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Sample records for 3d reservoir simulation

  1. 3D scientific visualization of reservoir simulation post-processing

    SciTech Connect

    Sousa, M.C.; Miranda-Filho, D.N.

    1994-12-31

    This paper describes a 3D visualization software designed at PETROBRAS and TecGraf/PUC-RJ in Brazil for the analysis of reservoir engineering post-processing data. It offers an advanced functional environment on graphical workstations with intuitive and ergonomic interface. Applications to real reservoir models show the enriching features of the software.

  2. The benefits of enhanced integration capabilities in 3-D reservoir modelling and simulation

    SciTech Connect

    O`Rourke, S.T.; Ikwumonu, A.

    1996-12-31

    The use of proprietary, closely linked 3-D geological and reservoir simulation software has greatly enhanced the reservoir modelling process by enabling complete integration of geological and engineering data in a 3-D manner. The software were used to model and simulate a deltaic sandstone reservoir in the Nigerian Forcados Yokri field in order to describe the reservoir sweep pattern. A simple simulation of the reservoir was first carried out to identify the main controls on the reservoir performance, which in this case were the intra-reservoir shales. As they are the only baffles or barriers to flow, proper modelling of them was critical to achieving a history match. Well logs, 3-D seismic, limited core data and sequence stratigraphic concepts were used to define a three dimensional depositional model which was then used to guide the 3-D reservoir architecture modelling. The reservoir model was evaluated in the 3-D simulator and, when the initial model did not yield a proper match with the historical production data, alternative models were easily generated and simulated until an acceptable match was achieved. The result was a 10% increase in predicted ultimate recovery, a better understanding of the reservoir and an optimized reservoir depletion plan.

  3. Simulation of water temperature in two reservoirs with Delft3d

    NASA Astrophysics Data System (ADS)

    Yang, J. Y.; Zhou, L. Y.

    2016-08-01

    The proposeled Guanjingkou and Fengdou reservoir will be constructed at Chongqing city and Muling city in China respectively. The water temperature in the reservoir, in the downstream, and the aquatic ecosystem would be altered by the construction of the reservoirs. This paper simulates the water temperature in the two reservoirs by using the Delft3d z-layer model, which uses the fixed elevation for layers. According to the simulation results, the temperature profile in the reservoirs can be divided into three layers: the upmost epilimnion layer, the beneathed thermocline layer, and the constant tepmerature layer at bottom. The temperature effects can be reduced by measurements of stoplogs gates and mutiple gates, respectively. Based on the simulation results in the wet, nomal, and dry year, the temperature of water released from the stoplogs gates at Guanjingkou reservior can be respectively increased by 5.7°C, 6.8°C, 9.6°C, and 5.5°C in the irrigation season from May to August. The temperature of water released from the mutiple gates at Fengdou reservior can be respectively increased by 7.7 °C, 1.9 °C, 9.5 °C, and 10.1 °C from May to August. The negative impacts from the water with lower temperature on the related ecosystem can be significently alleviated.

  4. Predicting the natural state of fractured carbonate reservoirs: An Andector Field, West Texas test of a 3-D RTM simulator

    SciTech Connect

    Tuncay, K.; Romer, S.; Ortoleva, P.; Hoak, T.; Sundberg, K.

    1998-12-31

    The power of the reaction, transport, mechanical (RTM) modeling approach is that it directly uses the laws of geochemistry and geophysics to extrapolate fracture and other characteristics from the borehole or surface to the reservoir interior. The objectives of this facet of the project were to refine and test the viability of the basin/reservoir forward modeling approach to address fractured reservoir in E and P problems. The study attempts to resolve the following issues: role of fracturing and timing on present day location and characteristics; clarifying the roles and interplay of flexure dynamics, changing rock rheological properties, fluid pressuring and tectonic/thermal histories on present day reservoir location and characteristics; and test the integrated RTM modeling/geological data approach on a carbonate reservoir. Sedimentary, thermal and tectonic data from Andector Field, West Texas, were used as input to the RTM basin/reservoir simulator to predict its preproduction state. The results were compared with data from producing reservoirs to test the RTM modeling approach. The effects of production on the state of the field are discussed in a companion report. The authors draw the following conclusions: RTM modeling is an important new tool in fractured reservoir E and P analysis; the strong coupling of RTM processes and the geometric and tensorial complexity of fluid flow and stresses require the type of fully coupled, 3-D RTM model for fracture analysis as pioneered in this project; flexure analysis cannot predict key aspects of fractured reservoir location and characteristics; fracture history over the lifetime of a basin is required to understand the timing of petroleum expulsion and migration and the retention properties of putative reservoirs.

  5. Sensitivity Studies of 3D Geothermal Reservoir Simulation: A Case Study in I-Lan Plain, Taiwan

    NASA Astrophysics Data System (ADS)

    Kuo, C. W.; Song, S. R.

    2015-12-01

    A large scale geothermal project conducted by Ministry of Science and Technology is initiated recently in I-Lan south area, northeastern Taiwan. The ultimate goal of this national project is to increase the percentage of renewable energy (ex. geothermal energy) to generate electricity. An integrated team which consists of various specialties are held together to investigate I-Lan area comprehensively. For example, I-Lan geological data, petrophysical analysis, seismicity, temperature gradient and distribution, hydrology, geochemistry, and heat source study etc. The geothermal gradient measured at one drilling well (1200m deep) is up to 50˚C/km and the prediction of temperature based on fluid inclusion analysis could be up to 300˚C. The geothermal reservoir is expected to occur at a fractured geological formation, Siling sandstone layer. A 3D subsurface geological model is built mainly based on the seismic exploration of the subsurface structure and well log data. According to the current conceptual model, the target area is bounded by two main faults, Jiaosi and Choshui faults. The preliminary results from all the investigations are integrated and used as input parameters to create a realistic numerical reservoir model. Numerical simulator TOUGH2 is used to study the geothermal energy potential. The initial state of temperature distribution is simulated and compared to the high resolution of magnetotelluric (MT) data. Simulation results show that they have similar pattern and therefore the prediction of geothermal potential in this area would be more reliable. Based on the realistic initial state, sensitivity studies are performed to investigate effects of relevant parameters on temperature distribution.

  6. Geological and Petrophysical Characterization of the Ferron Sandstone for 3-D Simulation of a Fluvial-Deltaic Reservoir

    SciTech Connect

    Chidsey Jr., Thomas C.

    2001-10-31

    The objective of the Ferron Sandstone project was to develop a comprehensive, interdisciplinary, quantitative characterization f fluvial-deltaic reservoir to allow realistic interwell and reservoir-scale models to be developed for improved oil-field development in similar reservoirs world-wide. Quantitative geological and petrophysical information on the Cretaceous Ferron Sandstone in east-central Utah was collected. Both new and existing data was integrated into a three-dimensional model of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Simulation results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations.

  7. 3D Surgical Simulation

    PubMed Central

    Cevidanes, Lucia; Tucker, Scott; Styner, Martin; Kim, Hyungmin; Chapuis, Jonas; Reyes, Mauricio; Proffit, William; Turvey, Timothy; Jaskolka, Michael

    2009-01-01

    This paper discusses the development of methods for computer-aided jaw surgery. Computer-aided jaw surgery allows us to incorporate the high level of precision necessary for transferring virtual plans into the operating room. We also present a complete computer-aided surgery (CAS) system developed in close collaboration with surgeons. Surgery planning and simulation include construction of 3D surface models from Cone-beam CT (CBCT), dynamic cephalometry, semi-automatic mirroring, interactive cutting of bone and bony segment repositioning. A virtual setup can be used to manufacture positioning splints for intra-operative guidance. The system provides further intra-operative assistance with the help of a computer display showing jaw positions and 3D positioning guides updated in real-time during the surgical procedure. The CAS system aids in dealing with complex cases with benefits for the patient, with surgical practice, and for orthodontic finishing. Advanced software tools for diagnosis and treatment planning allow preparation of detailed operative plans, osteotomy repositioning, bone reconstructions, surgical resident training and assessing the difficulties of the surgical procedures prior to the surgery. CAS has the potential to make the elaboration of the surgical plan a more flexible process, increase the level of detail and accuracy of the plan, yield higher operative precision and control, and enhance documentation of cases. Supported by NIDCR DE017727, and DE018962 PMID:20816308

  8. BM platform, B Field, Offshore Northwest Java: A case history of multi-disciplinary integration including 3D seismic, reservoir simulation and horizontal drilling

    SciTech Connect

    Cooke, D.; Aziz, A.; Baldauff, J.; Diswarin, N.

    1996-12-31

    This case history describes how a multidisciplinary team used a 3D survey and reservoir simulation to review and revise the development plans for the BM platform, located in the B Field, Offshore Northwest Java, Indonesia. The case history starts with the collection of necessary parophysical, geologic and production data. These data are input to a reservoir simulation which shows there should be no problems with the new platform. However, this initial simulation has known problems with contradicting input structure maps and fluid contacts. Hopefully, these problems can be addressed with a new 3D seismic survey - if the seismic data can be acquired, processed, interpreted and input to the simulation before drilling starts at the BM platform. The seismic acquisition could not be done with the traditional towed seismic streamer cables - instead stationary ocean bottom cables with dual geophone-hydrophone sensors were used. Processing of the seismic data was done in a way that allowed interpretation of the critical area even before acquisition of the entire survey was finished. The new 3D structure maps changed the MDT`s opinion of what reservoir and what areas contained the bulk of the oil reserves. Unfortunately, the new maps were not available until after the jacket was set but before the wells drilled. The NMT updated the simulation with the new 3D data, which led to changes in development well bottom hole locations and an ambitious horizontal well.

  9. Geological and Petrophysical Characterization of the Ferron Sandstone for 3-D Simulation of a Fluvial-Deltaic Reservoir

    SciTech Connect

    M. Lee Allison

    1997-03-01

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reser v oir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similiar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined . Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations . Transfer of the project results to the petroleum industry is an integral component of the project. Four activities continued this quarter as part of the geological and petrophysical characterization of the fluvial-deltaic Ferron Sandstone in the Ivie Creek case-study area: (1) geostatistics, (2) field description of clinoform bounding surfaces, (3) reservoir modeling, and (4) technology transfer.

  10. Geology and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Annual report, October 1, 1996--September 30, 1997

    SciTech Connect

    Chidsey, T.C. Jr.; Anderson, P.B.; Morris, T.H.; Dewey, J.A. Jr.; Mattson, A.; Foster, C.B.; Snelgrove, S.H.; Ryer, T.A.

    1998-05-01

    The objective of the Ferron Sandstone (Utah) project is to develop a comprehensive, interdisciplinary, quantitative characterization of a fluvial-deltaic reservoir to allow realistic interwell and reservoir-scale models to be developed for improved oil-field development in similar reservoirs world-wide. Both new and existing data is being integrated into a 3-D model of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Simulation results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. The project is divided into four tasks: (1) regional stratigraphic analysis, (2) case studies, (3) reservoirs models, and (4) field-scale evaluation of exploration strategies. The primary objective of the regional stratigraphic analysis is to provide a more detailed interpretation of the stratigraphy and gross reservoir characteristics of the Ferron Sandstone as exposed in outcrop. The primary objective of the case-studies work is to develop a detailed geological and petrophysical characterization, at well-sweep scale or smaller, of the primary reservoir lithofacies typically found in a fluvial-dominated deltaic reservoir. Work on tasks 3 and 4 consisted of developing two- and three-dimensional reservoir models at various scales. The bulk of the work on these tasks is being completed primarily during the last year of the project, and is incorporating the data and results of the regional stratigraphic analysis and case-studies tasks.

  11. Reservoir geology using 3D modelling tools

    SciTech Connect

    Dubrule, O.; Samson, P.; Segonds, D.

    1996-12-31

    The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified. Once the tectonic framework has been obtained, intermediate stratigraphic surfaces can be constructed between the main structural surfaces. Within each layer, reservoir attributes can be represented using various techniques. Examples show how the distribution of different facies (i.e. from fine to coarse grain) can be represented, or how various depositional units (for instance channels, crevasses and lobes in a turbidite setting) can be modelled as geological {open_quotes}objects{close_quotes} with complex geometries. Elf Aquitaine, in close co-operation with the GOCAD project in Nancy (France) is investigating how geological models can be made more realistic by developing interactive functionalities. Examples show that, contrary to standard deterministic or geostatistical modelling techniques (which tend to be difficult to control) the use of new 3D tools allows the geologist to interactively modify geological surfaces (including faults) or volumetric properties. Thus, the sensitivity of various economic parameters (oil in place, connected volumes, reserves) to major geological uncertainties can be evaluated. It is argued that future breakthroughs in geological modelling techniques are likely to happen in the development of interactive approaches rather than in the research of new mathematical algorithms.

  12. Reservoir geology using 3D modelling tools

    SciTech Connect

    Dubrule, O. ); Samson, P. ); Segonds, D. )

    1996-01-01

    The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified. Once the tectonic framework has been obtained, intermediate stratigraphic surfaces can be constructed between the main structural surfaces. Within each layer, reservoir attributes can be represented using various techniques. Examples show how the distribution of different facies (i.e. from fine to coarse grain) can be represented, or how various depositional units (for instance channels, crevasses and lobes in a turbidite setting) can be modelled as geological [open quotes]objects[close quotes] with complex geometries. Elf Aquitaine, in close co-operation with the GOCAD project in Nancy (France) is investigating how geological models can be made more realistic by developing interactive functionalities. Examples show that, contrary to standard deterministic or geostatistical modelling techniques (which tend to be difficult to control) the use of new 3D tools allows the geologist to interactively modify geological surfaces (including faults) or volumetric properties. Thus, the sensitivity of various economic parameters (oil in place, connected volumes, reserves) to major geological uncertainties can be evaluated. It is argued that future breakthroughs in geological modelling techniques are likely to happen in the development of interactive approaches rather than in the research of new mathematical algorithms.

  13. How 3-D, 3-C seismic characterized a carbonate reservoir

    SciTech Connect

    Arestad, J.F.; Mattocks, B.W.; Davis, T.L.; Benson, R.D.

    1995-04-01

    The Reservoir Characterization Project (RCP) at the Colorado School of Mines has pioneered research into 3-D, 3-C (multicomponent) reflection seismology for nearly a decade utilizing both P-wave and S-wave sources. Multicomponent-seismic surveys provide significantly more information about petroleum reservoirs than compressional-wave surveys. Initial 3-D, 3-C surveys acquired by RCP were targeted at characterizing naturally fractured reservoirs. The current phase of the project is oriented towards utilizing shear waves to discriminate lithologic and diagenetic changes within stratigraphic reservoirs where compressional-seismic data has not be effective. The Joffre field, Nisku reservoir, is the site of RCP`s ongoing multidisciplinary research effort in Western Canada. The research team is directed by Colorado School of Mines faculty with graduate team members from geology, geophysics and petroleum engineering departments. While this study is still in progress, some key findings and directions of this research are reported here. The following topics will be discussed: Joffre field 3-D, 3-C survey; compressional wave 3-D technique; shear-wave 3-D technique; converted-wave 3-D technique; reservoir characterization, and future directions.

  14. Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Technical progress report, July 1, 1996--September 30, 1996

    SciTech Connect

    Allison, M.L.

    1996-10-01

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project.

  15. Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Technical progress report, April 1--June 30, 1995

    SciTech Connect

    Allison, M.L.

    1995-07-28

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Technical progress this quarter is divided into regional stratigraphy, case studies, stochastic modeling and fluid-flow simulation, and technology transfer activities. The regional stratigraphy of the Ferron Sandstone outcrop belt from Last Chance Creek to Ferron Creek is being described and interpreted. Photomosaics and a database of existing surface and subsurface data are being used to determine the extent and depositional environment of each parasequence, and the nature of the contacts with adjacent rocks or flow units. For the second field season, detailed geological and petrophysical characterization of the primary reservoir lithofacies typically found in a fluvial-dominated deltaic reservoir, is continuing at selected case-study areas.

  16. Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Annual report, October 1, 1995--September 30, 1996

    SciTech Connect

    Chidsey, T.C. Jr.

    1997-05-01

    The objective of the Ferron Sandstone project is to develop a comprehensive, interdisciplinary, quantitative characterization of a fluvial-deltaic reservoir to allow realistic inter-well and reservoir-scale models to be developed for improved oil-field development in similar reservoirs world-wide. Quantitative geological and petrophysical information on the Cretaceous Ferron Sandstone in east-central Utah was collected. Both new and existing data is being integrated into a three-dimensional model of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Simulation results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project. This report covers research activities for fiscal year 1995-96, the third year of the project. Most work consisted of interpreting the large quantity of data collected over two field seasons. The project is divided into four tasks: (1) regional stratigraphic analysis, (2) case studies, (3) reservoirs models, and (4) field-scale evaluation of exploration strategies. The primary objective of the regional stratigraphic analysis is to provide a more detailed interpretation of the stratigraphy and gross reservoir characteristics of the Ferron Sandstone as exposed in outcrop. The primary objective of the case-studies work is to develop a detailed geological and petrophysical characterization, at well-sweep scale or smaller, of the primary reservoir lithofacies typically found in a fluvial-dominated deltaic reservoir.

  17. Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Quarterly progress report, July 1--September 30, 1995

    SciTech Connect

    Allison, M.L.

    1995-10-30

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project. Technical progress this quarter is divided into regional stratigraphy, case studies, stochastic modeling and fluid-flow simulation, and technology transfer activities. The regional stratigraphy of the Ferron Sandstone outcrop belt is being described and interpreted. Detailed geological and petrophysical characterization of the primary reservoir lithofacies typically found in a fluvial-dominated deltaic reservoir, is continuing at selected case-study areas. Interpretations of lithofacies, bounding surfaces, and other geologic information are being combined with permeability measurements from closely spaced traverses and from drill-hole cores (existing and two drilled during the quarter). Petrophysical and statistical analyses are being incorporated with the geological characterization to develop a three-dimensional model of the reservoirs through fluid-flow simulation.

  18. Interactive 3D visualization speeds well, reservoir planning

    SciTech Connect

    Petzet, G.A.

    1997-11-24

    Texaco Exploration and Production has begun making expeditious analyses and drilling decisions that result from interactive, large screen visualization of seismic and other three dimensional data. A pumpkin shaped room or pod inside a 3,500 sq ft, state-of-the-art facility in Southwest Houston houses a supercomputer and projection equipment Texaco said will help its people sharply reduce 3D seismic project cycle time, boost production from existing fields, and find more reserves. Oil and gas related applications of the visualization center include reservoir engineering, plant walkthrough simulation for facilities/piping design, and new field exploration. The center houses a Silicon Graphics Onyx2 infinite reality supercomputer configured with 8 processors, 3 graphics pipelines, and 6 gigabytes of main memory.

  19. Geological and petrophysical characterization of the ferron sandstone for 3-D simulation of a fluvial-deltaic reservoir. Annual report, October 1, 1994--September 30, 1995

    SciTech Connect

    Chidsey, T.C. Jr.; Allison, M.L.

    1996-05-01

    The objective of the Ferron Sandstone project is to develop a comprehensive, interdisciplinary, quantitative characterization of a fluvial-deltaic reservoir to allow realistic interwell and reservoir-scale models to be developed for improved oil-field development in similar reservoirs world-wide. Quantitative geological and petrophysical information on the Cretaceous Ferron Sandstone in east-central Utah was collected. Both new and existing data is being integrated into a three-dimensional model of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Simulation results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project. This report covers research activities for fiscal year 1994-95, the second year of the project. Most work consisted of developing field methods and collecting large quantities of existing and new data. We also continued to develop preliminary regional and case-study area interpretations. The project is divided into four tasks: (1) regional stratigraphic analysis, (2) case studies, (3) reservoirs models, and (4) field-scale evaluation of exploration strategies.

  20. Geological and petrophysical characterization of the ferron sandstone for 3-D simulation of a fluvial-deltaic reservoir. Quarterly report, January 1 - March 31, 1996

    SciTech Connect

    Allison, M.L.

    1996-04-01

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial- deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Technical progress this quarter is divided into case-study evaluation, geostatistics, and technology transfer activities. The work focused on one parasequence set, referred to as the Kf-1, in the Willow Springs Wash and Ivie Creek case-study areas. In the Ivie Creek case-study area the Kf-1 represents a river-dominated delta deposit which changes from proximal to distal from east to west. In the Willow Springs Wash case-study area the Kf-1 contains parasequences which represent river-dominated and wave-modified environments of deposition. Interpretations of lithofacies, bounding surfaces, and other geologic information are being used to determine reservoir architecture. Graphical interpretations of important flow boundaries in the case-study areas, identified on photomosaics, are being used to construct cross sections, paleogeographic, maps, and reservoir models. Geostatistical analyses are being incorporated with the geological characterization to develop a three-dimensional model of the reservoirs for fluid-flow simulation.

  1. Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Quarterly report, July 1--September 30, 1997

    SciTech Connect

    Allison, M.L.

    1997-11-01

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Two activities continued this quarter as part of the geological and petrophysical characterization of the fluvial-deltaic Ferron Sandstone: (1) evaluation of the Ivie Creek and Willow Springs Wash case-study areas and (2) technology transfer.

  2. Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Quarterly report, April 1--June 30, 1998

    SciTech Connect

    Chidsey, T.C. Jr.

    1998-07-01

    The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project. Two activities continued this quarter as part of the geological and petrophysical characterization of the fluvial-deltaic Ferron Sandstone: (1) preparation of the project final report and (2) technology transfer.

  3. 3D Simulation: Microgravity Environments and Applications

    NASA Technical Reports Server (NTRS)

    Hunter, Steve L.; Dischinger, Charles; Estes, Samantha; Parker, Nelson C. (Technical Monitor)

    2001-01-01

    Most, if not all, 3-D and Virtual Reality (VR) software programs are designed for one-G gravity applications. Space environments simulations require gravity effects of one one-thousandth to one one-million of that of the Earth's surface (10(exp -3) - 10(exp -6) G), thus one must be able to generate simulations that replicate those microgravity effects upon simulated astronauts. Unfortunately, the software programs utilized by the National Aeronautical and Space Administration does not have the ability to readily neutralize the one-G gravity effect. This pre-programmed situation causes the engineer or analysis difficulty during micro-gravity simulations. Therefore, microgravity simulations require special techniques or additional code in order to apply the power of 3D graphic simulation to space related applications. This paper discusses the problem and possible solutions to allow microgravity 3-D/VR simulations to be completed successfully without program code modifications.

  4. Building the 3-D jugsaw puzzle: Applications of sequence stratigraphy to 3-D reservoir characterization, Permian basin

    SciTech Connect

    Tinker, S.W.

    1996-04-01

    Reservoir characterization involves the quantification, integration, reduction, and analysis of geological, petrophysical, seismic, and engineering data. This is no small task. A principal goal of reservoir characterization is to derive a spatial understanding of interwell heterogeneity. Traditionally, geologic attempts to characterize interwell heterogeneity have been done using hand-drawn or computer-generated two-dimensional (2-D) maps and cross sections. Results can be improved dramatically using three-dimensional (3-D) interpretation and analysis techniques. Three-dimensional reservoir characterization requires the same input data used in 2-D approaches, and the cost is equal to, and commonly lower than, traditional 2-D methods. The product of 3-D reservoir characterization is a 3-D reservoir model. The language used to communicate the results of a 3-D reservoir model is visualization; i.e., visual images of numerical data. All of the available log and core data in a model area are incorporated in a 3-D model, but the data are depicted as colored cells rather than as log traces. The integrity of the 3-D reservoir model is largely a function of the stratigraphic framework. Interpreting the correct stratigraphic framework for a subsurface reservoir is the most difficult and creative part of the 3-D modeling process. Sequence and seismic stratigraphic interpretation provide the best stratigraphic framework for 3-D reservoir modeling. The purpose of this paper is to discuss the pro- cess of 3-D deterministic reservoir modeling and to illustrate the advantages of using a sequence stratigraphic framework in 3-D modeling. Mixed carbonate and siliciclastic sediment outcrop and subsurface examples from the Permian basin of west Texas and New Mexico will be used as examples, but the concepts and techniques can be applied to reservoirs of any age.

  5. An Assessment of Some Design Constraints on Heat Production of a 3D Conceptual EGS Model Using an Open-Source Geothermal Reservoir Simulation Code

    SciTech Connect

    Yidong Xia; Mitch Plummer; Robert Podgorney; Ahmad Ghassemi

    2016-02-01

    Performance of heat production process over a 30-year period is assessed in a conceptual EGS model with a geothermal gradient of 65K per km depth in the reservoir. Water is circulated through a pair of parallel wells connected by a set of single large wing fractures. The results indicate that the desirable output electric power rate and lifespan could be obtained under suitable material properties and system parameters. A sensitivity analysis on some design constraints and operation parameters indicates that 1) the fracture horizontal spacing has profound effect on the long-term performance of heat production, 2) the downward deviation angle for the parallel doublet wells may help overcome the difficulty of vertical drilling to reach a favorable production temperature, and 3) the thermal energy production rate and lifespan has close dependence on water mass flow rate. The results also indicate that the heat production can be improved when the horizontal fracture spacing, well deviation angle, and production flow rate are under reasonable conditions. To conduct the reservoir modeling and simulations, an open-source, finite element based, fully implicit, fully coupled hydrothermal code, namely FALCON, has been developed and used in this work. Compared with most other existing codes that are either closed-source or commercially available in this area, this new open-source code has demonstrated a code development strategy that aims to provide an unparalleled easiness for user-customization and multi-physics coupling. Test results have shown that the FALCON code is able to complete the long-term tests efficiently and accurately, thanks to the state-of-the-art nonlinear and linear solver algorithms implemented in the code.

  6. INCORPORATING DYNAMIC 3D SIMULATION INTO PRA

    SciTech Connect

    Steven R Prescott; Curtis Smith

    2011-07-01

    Through continued advancement in computational resources, development that was previously done by trial and error production is now performed through computer simulation. These virtual physical representations have the potential to provide accurate and valid modeling results and are being used in many different technical fields. Risk assessment now has the opportunity to use 3D simulation to improve analysis results and insights, especially for external event analysis. By using simulations, the modeler only has to determine the likelihood of an event without having to also predict the results of that event. The 3D simulation automatically determines not only the outcome of the event, but when those failures occur. How can we effectively incorporate 3D simulation into traditional PRA? Most PRA plant modeling is made up of components with different failure modes, probabilities, and rates. Typically, these components are grouped into various systems and then are modeled together (in different combinations) as a “system” with logic structures to form fault trees. Applicable fault trees are combined through scenarios, typically represented by event tree models. Though this method gives us failure results for a given model, it has limitations when it comes to time-based dependencies or dependencies that are coupled to physical processes which may themselves be space- or time-dependent. Since, failures from a 3D simulation are naturally time related, they should be used in that manner. In our simulation approach, traditional static models are converted into an equivalent state diagram representation with start states, probabilistic driven movements between states and terminal states. As the state model is run repeatedly, it converges to the same results as the PRA model in cases where time-related factors are not important. In cases where timing considerations are important (e.g., when events are dependent upon each other), then the simulation approach will typically

  7. 3D inversion of time-lapse CSEM data for reservoir monitoring

    NASA Astrophysics Data System (ADS)

    Black, N.; Wilson, G. A.; Zhdanov, M. S.

    2010-12-01

    Effective reservoir monitoring requires time-lapse reservoir information throughout the interwell volume. The ability to understand and control reservoir behavior over the course of production allows for optimization of reservoir performance and production strategies. Good monitoring information makes it possible to improve the timing and location of new drilling (for both production and injection wells), to recognize flow paths, and to map oil that has been bypassed. Recent studies have inferred the feasibility of time-lapse marine controlled-source electromagnetic (CSEM) methods for the monitoring of offshore oil and gas fields. However, quantitative interpretations to ascertain what reservoir information may be recovered have not been performed. The time-lapse CSEM inverse problem can be highly constrained since the geometry of the reservoir is established prior from high resolution seismic surveys, rock and fluid properties are measured from well logs, and multiple history matched production scenarios are contained in dynamic reservoir models. We present a 3D inversion study of synthetic time-lapse CSEM data modeled from dynamic reservoir simulations. We demonstrate that even with few constraints on the model, the hydrocarbon-water front can be recovered from 3D inversion.

  8. Simulation of 3D diamond detectors

    NASA Astrophysics Data System (ADS)

    Forcolin, G. T.; Oh, A.; Murphy, S. A.

    2017-02-01

    3D diamond detectors present an interesting prospect for future Particle Physics experiments. They have been studied in detail at beam tests with 120 GeV protons and 4 MeV protons. To understand the observations that have been made, simulations have been carried out using Synopsys TCAD in order to explain the movement of charge carriers within the sample, as well as the effects of charge sharing. Reasonable agreement has been observed between simulation and experiment.

  9. Integration of 3D photogrammetric outcrop models in the reservoir modelling workflow

    NASA Astrophysics Data System (ADS)

    Deschamps, Remy; Joseph, Philippe; Lerat, Olivier; Schmitz, Julien; Doligez, Brigitte; Jardin, Anne

    2014-05-01

    3D technologies are now widely used in geosciences to reconstruct outcrops in 3D. The technology used for the 3D reconstruction is usually based on Lidar, which provides very precise models. Such datasets offer the possibility to build well-constrained outcrop analogue models for reservoir study purposes. The photogrammetry is an alternate methodology which principles are based in determining the geometric properties of an object from photographic pictures taken from different angles. Outcrop data acquisition is easy, and this methodology allows constructing 3D outcrop models with many advantages such as: - light and fast acquisition, - moderate processing time (depending on the size of the area of interest), - integration of field data and 3D outcrops into the reservoir modelling tools. Whatever the method, the advantages of digital outcrop model are numerous as already highlighted by Hodgetts (2013), McCaffrey et al. (2005) and Pringle et al. (2006): collection of data from otherwise inaccessible areas, access to different angles of view, increase of the possible measurements, attributes analysis, fast rate of data collection, and of course training and communication. This paper proposes a workflow where 3D geocellular models are built by integrating all sources of information from outcrops (surface picking, sedimentological sections, structural and sedimentary dips…). The 3D geomodels that are reconstructed can be used at the reservoir scale, in order to compare the outcrop information with subsurface models: the detailed facies models of the outcrops are transferred into petrophysical and acoustic models, which are used to test different scenarios of seismic and fluid flow modelling. The detailed 3D models are also used to test new techniques of static reservoir modelling, based either on geostatistical approaches or on deterministic (process-based) simulation techniques. A modelling workflow has been designed to model reservoir geometries and properties from

  10. Faster Aerodynamic Simulation With Cart3D

    NASA Technical Reports Server (NTRS)

    2003-01-01

    A NASA-developed aerodynamic simulation tool is ensuring the safety of future space operations while providing designers and engineers with an automated, highly accurate computer simulation suite. Cart3D, co-winner of NASA's 2002 Software of the Year award, is the result of over 10 years of research and software development conducted by Michael Aftosmis and Dr. John Melton of Ames Research Center and Professor Marsha Berger of the Courant Institute at New York University. Cart3D offers a revolutionary approach to computational fluid dynamics (CFD), the computer simulation of how fluids and gases flow around an object of a particular design. By fusing technological advancements in diverse fields such as mineralogy, computer graphics, computational geometry, and fluid dynamics, the software provides a new industrial geometry processing and fluid analysis capability with unsurpassed automation and efficiency.

  11. Crashworthiness simulations with DYNA3D

    SciTech Connect

    Schauer, D.A.; Hoover, C.G.; Kay, G.J.; Lee, A.S.; De Groot, A.J.

    1996-04-01

    Current progress in parallel algorithm research and applications in vehicle crash simulation is described for the explicit, finite element algorithms in DYNA3D. Problem partitioning methods and parallel algorithms for contact at material interfaces are the two challenging algorithm research problems that are addressed. Two prototype parallel contact algorithms have been developed for treating the cases of local and arbitrary contact. Demonstration problems for local contact are crashworthiness simulations with 222 locally defined contact surfaces and a vehicle/barrier collision modeled with arbitrary contact. A simulation of crash tests conducted for a vehicle impacting a U-channel small sign post embedded in soil has been run on both the serial and parallel versions of DYNA3D. A significant reduction in computational time has been observed when running these problems on the parallel version. However, to achieve maximum efficiency, complex problems must be appropriately partitioned, especially when contact dominates the computation.

  12. 3D modelling and characterization of delta reservoir in SE-Hungary

    SciTech Connect

    Geiger, J.; Komlosi, J.

    1995-08-01

    The Algyo field is the largest field of Hungary consisting of more than 40 oil and gas bearing layers. The upper part of this field developed in delta slope and delta plain units of a progradational delta system, the lower members are turbidity rock bodies of prodelta and deep basin fans. As a type analogy ofthe reservoirs developed in Miocene-Pliocene progradational delta systems, the reservoir {open_quotes}Szeged-1{close_quotes} of the Algyo field has been chosen. It has been penetrated by 912 wells over an area of about 60 square km. This reservoir is interpreted as an alternation of distributary channels and inter-distributary swamp areas. About 40 cores with 100% core recovery was taken. The reservoir has been on stream since the late 60`-s, the geological model can be controlled by the data of the reservoir engineering. An integrated 3-D reservoir description based on a grid-oriented 3-D geostatistical visualisation of the internal lithological and petrophysical heterogeneity has been developed, This system integrates data of core descriptions, standard and special core analyses, and petrophysical well-log interpretations. The reservoir geometry and lithological heterogenity have been characterized by two models: Markov-model for the lithological transitions, and the 3D-grid-based geostatistical model for the visualisation. The 3-D visualization of the petrophysical data expresses the dependence of recovery mechanism, and injection schemes on the real internal heterogeneity. These images may be generalized and used as conditional constraints for the simulation of internal heterogeneity of other Pannonian fields developed only by few wells.

  13. Evaluation of field development plans using 3-D reservoir modelling

    SciTech Connect

    Seifert, D.; Lewis, J.J.M.; Newbery, J.D.H.

    1997-08-01

    Three-dimensional reservoir modelling has become an accepted tool in reservoir description and is used for various purposes, such as reservoir performance prediction or integration and visualisation of data. In this case study, a small Northern North Sea turbiditic reservoir was to be developed with a line drive strategy utilising a series of horizontal producer and injector pairs, oriented north-south. This development plan was to be evaluated and the expected outcome of the wells was to be assessed and risked. Detailed analyses of core, well log and analogue data has led to the development of two geological {open_quotes}end member{close_quotes} scenarios. Both scenarios have been stochastically modelled using the Sequential Indicator Simulation method. The resulting equiprobable realisations have been subjected to detailed statistical well placement optimisation techniques. Based upon bivariate statistical evaluation of more than 1000 numerical well trajectories for each of the two scenarios, it was found that the wells inclinations and lengths had a great impact on the wells success, whereas the azimuth was found to have only a minor impact. After integration of the above results, the actual well paths were redesigned to meet external drilling constraints, resulting in substantial reductions in drilling time and costs.

  14. 3D liver surgery simulation: computer-assisted surgical planning with 3D simulation software and 3D printing.

    PubMed

    Oshiro, Yukio; Ohkohchi, Nobuhiro

    2017-03-27

    To perform accurate hepatectomy without injury, it is necessary to understand the anatomical relationship among the branches of Glisson's sheath, hepatic veins, and tumor. In Japan, three-dimensional (3D) preoperative simulation for liver surgery is becoming increasingly common, and liver 3D modeling and 3D hepatectomy simulation by 3D analysis software for liver surgery have been covered by universal healthcare insurance since 2012. Herein, we review the history of virtual hepatectomy using computer-aided surgery (CAS) and our research to date, and we discuss the future prospects of CAS. We have used the SYNAPSE VINCENT medical imaging system (Fujifilm Medical, Tokyo, Japan) for 3D visualization and virtual resection of the liver since 2010. We developed a novel fusion imaging technique combining 3D computed tomography (CT) with magnetic resonance imaging (MRI). The fusion image enables us to easily visualize anatomic relationships among the hepatic arteries, portal veins, bile duct, and tumor in the hepatic hilum. In 2013, we developed an original software, called Liversim, that enables real-time deformation of the liver using physical simulation, and a randomized control trial has recently been conducted to evaluate the use of Liversim and SYNAPSE VINCENT for preoperative simulation and planning. Furthermore, we developed a novel hollow 3D-printed liver model whose surface is covered with frames. This model is useful for safe liver resection, has better visibility, and the production cost is reduced to one-third of a previous model. Preoperative simulation and navigation with CAS in liver resection are expected to help planning and conducting a surgery and surgical education. Thus, a novel CAS system will contribute to not only the performance of reliable hepatectomy but also to surgical education.

  15. Quasi-3D space charge simulation

    SciTech Connect

    Yang, Xi; /Fermilab

    2007-04-01

    The longitudinal space charge effect is simulated by binning the longitudinal beam profile in order to calculate the force on the bins using the binned particle distribution via FFT, and applying momentum kick based upon this space charge force to macro-particles. Usually, the longitudinal space charge kick is calculated once per turn since the longitudinal profile doesn't change much in a single turn. Besides, the longitudinal profile is used as a weighting factor for the transverse space charge force. The transverse space charge effect is simulated by projecting the 3-D beam to a 2-D Gaussian distribution in order to use the complex error function to compute the transverse space charge force, and applying this space charge force to macro-particles. One transverse space charge calculation per scale length of the beam shape variation requires at least ten transverse space charge force calculations per betatron oscillation.

  16. (abstract) 3D Electromagnetic Plasma Particle Simulations

    NASA Technical Reports Server (NTRS)

    Wang, J.; Liewer, P. C.; Lyster, P.; Decyk, V. K.

    1993-01-01

    A 3D electromagnetic plasma particle-in-cell code has been developed using the General Concurrent PIC algorithm. The GCPIC algorithm uses a domain decomposition to divide the computation among the processors. Particles must be exchanged between processors as they move. The efficiencies for 1-, 2-, and 3-dimensional partitions of the three dimensional domain are compared, and the algorithm is found to be very efficient even when a large fraction (e.g., 30%) of the particles must be exchanged at every time step. This PIC code has been used to perform simulations of a variety of space plasma physics problems. Results of three applications will be discussed: 1) plasma disturbances induced by moving conducting bodies in a magnetized plasma; 2) plasma plume interactions; and 3) solar wind termination shock.

  17. Non-isothermal 3D SDPD Simulations

    NASA Astrophysics Data System (ADS)

    Yang, Jun; Potami, Raffaele; Gatsonis, Nikolaos

    2012-11-01

    The study of fluids at micro and nanoscale requires new modeling and computational approaches. Smooth Particle Dissipative Dynamics (SDPD) is a mesh-free method that provides a bridge between the continuum equations of hydrodynamics embedded in the Smooth Particle Hydrodynamics approach and the molecular nature embedded in the DPD approach. SDPD is thermodynamically consistent, does not rely on arbitrary coefficients for its thermostat, involves realistic transport coefficients, and includes fluctuation terms. SDPD is implemented in our work for arbitrary 3D geometries with a methodology to model solid wall boundary conditions. We present simulations for isothermal flows for verification of our approach. The entropy equation is implemented with a velocity-entropy Verlet integration algorithm Flows with heat transfer are simulated for verification of the SDPD. We present also the self-diffusion coefficient derived from SDPD simulations for gases and liquids. Results show the scale dependence of self-diffusion coefficient on SDPD particle size. Computational Mathematics Program of the Air Force Office of Scientific Research under grant/contract number FA9550-06-1-0236.

  18. 3D electrohydrodynamic simulation of electrowetting displays

    NASA Astrophysics Data System (ADS)

    Hsieh, Wan-Lin; Lin, Chi-Hao; Lo, Kuo-Lung; Lee, Kuo-Chang; Cheng, Wei-Yuan; Chen, Kuo-Ching

    2014-12-01

    The fluid dynamic behavior within a pixel of an electrowetting display (EWD) is thoroughly investigated through a 3D simulation. By coupling the electrohydrodynamic (EHD) force deduced from the Maxwell stress tensor with the laminar phase field of the oil-water dual phase, the complete switch processes of an EWD, including the break-up and the electrowetting stages in the switch-on process (with voltage) and the oil spreading in the switch-off process (without voltage), are successfully simulated. By considering the factor of the change in the apparent contact angle at the contact line, the electro-optic performance obtained from the simulation is found to agree well with its corresponding experiment. The proposed model is used to parametrically predict the effect of interfacial (e.g. contact angle of grid) and geometric (e.g. oil thickness and pixel size) properties on the defects of an EWD, such as oil dewetting patterns, oil overflow, and oil non-recovery. With the help of the defect analysis, a highly stable EWD is both experimentally realized and numerically analyzed.

  19. Integration of Petrophysical Methods and 3D Printing Technology to Replicate Reservoir Pore Systems

    NASA Astrophysics Data System (ADS)

    Ishutov, S.; Hasiuk, F.; Gray, J.; Harding, C.

    2014-12-01

    Pore-scale imaging and modeling are becoming routine geoscience techniques of reservoir analysis and simulation in oil and gas industry. Three-dimensional printing may facilitate the transformation of pore-space imagery into rock models, which can be compared to traditional laboratory methods and literature data. Although current methodologies for rapid rock modeling and printing obscure many details of grain geometry, computed tomography data is one route to refine pore networks and experimentally test hypotheses related to rock properties, such as porosity and permeability. This study uses three-dimensional printing as a novel way of interacting with x-ray computed tomography data from reservoir core plugs based on digital modeling of pore systems in coarse-grained sandstones and limestones. The advantages of using artificial rocks as a proxy are to better understand the contributions of pore system characteristics at various scales to petrophysical properties in oil and gas reservoirs. Pore radii of reservoir sandstones used in this study range from 1 to 100s of microns, whereas the pore radii for limestones vary from 0.01 to 10s of microns. The resolution of computed tomography imaging is ~10 microns; the resolution of 3D digital printing used in the study varies from 2.5 to 300 microns. For this technology to be useful, loss of pore network information must be minimized in the course of data acquisition, modeling, and production as well as verified against core-scale measurements. The ultimate goal of this study is to develop a reservoir rock "photocopier" that couples 3D scanning and modeling with 3D printing to reproduce a) petrophyscially accurate copies of reservoir pore systems and b) digitally modified pore systems for testing hypotheses about reservoir flow. By allowing us to build porous media with known properties (porosity, permeability, surface area), technology will also advance our understanding of the tools used to measure these quantities (e

  20. FRACTURED RESERVOIR E&P IN ROCKY MOUNTAIN BASINS: A 3-D RTM MODELING APPROACH

    SciTech Connect

    P. Ortoleva; J. Comer; A. Park; D. Payne; W. Sibo; K. Tuncay

    2001-11-26

    Key natural gas reserves in Rocky Mountain and other U.S. basins are in reservoirs with economic producibility due to natural fractures. In this project, we evaluate a unique technology for predicting fractured reservoir location and characteristics ahead of drilling based on a 3-D basin/field simulator, Basin RTM. Recommendations are made for making Basin RTM a key element of a practical E&P strategy. A myriad of reaction, transport, and mechanical (RTM) processes underlie the creation, cementation and preservation of fractured reservoirs. These processes are often so strongly coupled that they cannot be understood individually. Furthermore, sedimentary nonuniformity, overall tectonics and basement heat flux histories make a basin a fundamentally 3-D object. Basin RTM is the only 3-D, comprehensive, fully coupled RTM basin simulator available for the exploration of fractured reservoirs. Results of Basin RTM simulations are presented, that demonstrate its capabilities and limitations. Furthermore, it is shown how Basin RTM is a basis for a revolutionary automated methodology for simultaneously using a range of remote and other basin datasets to locate reservoirs and to assess risk. Characteristics predicted by our model include reserves and composition, matrix and fracture permeability, reservoir rock strength, porosity, in situ stress and the statistics of fracture aperture, length and orientation. Our model integrates its input data (overall sedimentation, tectonic and basement heat flux histories) via the laws of physics and chemistry that describe the RTM processes to predict reservoir location and characteristics. Basin RTM uses 3-D, finite element solutions of the equations of rock mechanics, organic and inorganic diagenesis and multi-phase hydrology to make its predictions. As our model predicts reservoir characteristics, it can be used to optimize production approaches (e.g., assess the stability of horizontal wells or vulnerability of fractures to

  1. 3D Simulations of the Beehive Proplyd

    NASA Astrophysics Data System (ADS)

    Feitosa, J. A.; Vasconcelos, M. J.; Cerqueira, A. H.

    2014-10-01

    Some star formation regions, like the Orion nebula, have stars of different masses, from massive stars, responsible for strong ionizing winds and HII regions, to low-mass stars, which spend a long time in the protostellar phase, and are frequently associated with protostellar disks and jets. Massive O or B stars emit a great deal of UV radiation, able to dissociate the hydrogen molecule (FUV radiation, energies between 6-13 eV), to ionize the atomic hydrogen (EUV radiation, energies greater than 13.6 eV) and heat the gas. Around these stars, a large and hot (10^{4}K) region is formed, known as HII region. T-Tauri stars inside HII regions produce a type of young stellar object, a proplyd, described with accuracy in O'Dell et al. (1993). Proplyds exhibit a cometary shape from which we can distinguish a central low-mass star with an accretion disk, an ionization front, a photodissociation region and, sometimes, an external bow shock and a protostellar jet. Its morphological characteristics depends on the distance between the low-mass star and the source of the ionizing radiation. The Beehive, a giant proplyd in Orion Nebula, has attracted attention due to its exotic system of rings coaxial to the HH540 jet's axis. Bally et al. (2005) suggested that the rings are perturbations due to the crossing of the ionization front by the jet. In this work, we test this hypothesis making 3D hydrodynamic numerical simulations over an adaptive grid, using the Yguazú-A code (Raga et al., 2000), properly adapted for the Beehive conditions. Our results show that the jet causes a perturbation in the ionization front of the proplyd, but is necessary to adjust carefully some parameters of the jet like its velocity and ejection frequency in order to have the results matching the observations.

  2. Geothermal reservoir simulation

    NASA Technical Reports Server (NTRS)

    Mercer, J. W., Jr.; Faust, C.; Pinder, G. F.

    1974-01-01

    The prediction of long-term geothermal reservoir performance and the environmental impact of exploiting this resource are two important problems associated with the utilization of geothermal energy for power production. Our research effort addresses these problems through numerical simulation. Computer codes based on the solution of partial-differential equations using finite-element techniques are being prepared to simulate multiphase energy transport, energy transport in fractured porous reservoirs, well bore phenomena, and subsidence.

  3. 3D Numerical simulations of oblique subduction

    NASA Astrophysics Data System (ADS)

    Malatesta, C.; Gerya, T.; Scambelluri, M.; Crispini, L.; Federico, L.; Capponi, G.

    2012-04-01

    In the past 2D numerical studies (e.g. Gerya et al., 2002; Gorczyk et al., 2007; Malatesta et al., 2012) provided evidence that during intraoceanic subduction a serpentinite channel forms above the downgoing plate. This channel forms as a result of hydration of the mantle wedge by uprising slab-fluids. Rocks buried at high depths are finally exhumed within this buoyant low-viscosity medium. Convergence rate in these 2D models was described by a trench-normal component of velocity. Several present and past subduction zones worldwide are however driven by oblique convergence between the plates, where trench-normal motion of the subducting slab is coupled with trench-parallel displacement of the plates. Can the exhumation mechanism and the exhumation rates of high-pressure rocks be affected by the shear component of subduction? And how uprise of these rocks can vary along the plate margin? We tried to address these questions performing 3D numerical models that simulate an intraoceanic oblique subduction. The models are based on thermo-mechanical equations that are solved with finite differences method and marker-in-cell techniques combined with multigrid approach (Gerya, 2010). In most of the models a narrow oceanic basin (500 km-wide) surrounded by continental margins is depicted. The basin is floored by either layered or heterogeneous oceanic lithosphere with gabbro as discrete bodies in serpentinized peridotite and a basaltic layer on the top. A weak zone in the mantle is prescribed to control the location of subduction initiation and therefore the plate margins geometry. Finally, addition of a third dimension in the simulations allowed us to test the role of different plate margin geometries on oblique subduction dynamics. In particular in each model we modified the dip angle of the weak zone and its "lateral" geometry (e.g. continuous, segmented). We consider "continuous" weak zones either parallel or increasingly moving away from the continental margins

  4. Simulation of 3D Chaotic Electroconvection in Shear Flow

    NASA Astrophysics Data System (ADS)

    Davidson, Scott; Mani, Ali

    2016-11-01

    Electroconvection, a microscale electrohydrodynamic phenomenon with chaotic features reminiscent of turbulence, provides the dominant transport mechanism in many electrochemical processes where ions are driven through ion-selective surfaces under large applied voltages. Electrodialysis, for example, desalinates water by flowing it between layers of ion-selective membranes with alternating selectivity while an electric field is applied normal to the membranes. This process leads to alternating channels becoming enriched and depleted of ions. Despite its key importance, much about how electroconvection enhances ion transport, particularly in the presence of crossflow, remains a mystery. We present results of 3D direct numerical simulations of electroconvection in a canonical geometry of an electrolyte between an ion-selective membrane and a reservoir with periodic sides subject to applied shear flow. We analyze the effects of crossflow on both flow statistics and qualitative structures in the fully chaotic regime. Stanford Graduate Fellowship, NSF GRFP.

  5. Porosity, permeability and 3D fracture network characterisation of dolomite reservoir rock samples.

    PubMed

    Voorn, Maarten; Exner, Ulrike; Barnhoorn, Auke; Baud, Patrick; Reuschlé, Thierry

    2015-03-01

    With fractured rocks making up an important part of hydrocarbon reservoirs worldwide, detailed analysis of fractures and fracture networks is essential. However, common analyses on drill core and plug samples taken from such reservoirs (including hand specimen analysis, thin section analysis and laboratory porosity and permeability determination) however suffer from various problems, such as having a limited resolution, providing only 2D and no internal structure information, being destructive on the samples and/or not being representative for full fracture networks. In this paper, we therefore explore the use of an additional method - non-destructive 3D X-ray micro-Computed Tomography (μCT) - to obtain more information on such fractured samples. Seven plug-sized samples were selected from narrowly fractured rocks of the Hauptdolomit formation, taken from wellbores in the Vienna basin, Austria. These samples span a range of different fault rocks in a fault zone interpretation, from damage zone to fault core. We process the 3D μCT data in this study by a Hessian-based fracture filtering routine and can successfully extract porosity, fracture aperture, fracture density and fracture orientations - in bulk as well as locally. Additionally, thin sections made from selected plug samples provide 2D information with a much higher detail than the μCT data. Finally, gas- and water permeability measurements under confining pressure provide an important link (at least in order of magnitude) towards more realistic reservoir conditions. This study shows that 3D μCT can be applied efficiently on plug-sized samples of naturally fractured rocks, and that although there are limitations, several important parameters can be extracted. μCT can therefore be a useful addition to studies on such reservoir rocks, and provide valuable input for modelling and simulations. Also permeability experiments under confining pressure provide important additional insights. Combining these and

  6. Porosity, permeability and 3D fracture network characterisation of dolomite reservoir rock samples

    PubMed Central

    Voorn, Maarten; Exner, Ulrike; Barnhoorn, Auke; Baud, Patrick; Reuschlé, Thierry

    2015-01-01

    With fractured rocks making up an important part of hydrocarbon reservoirs worldwide, detailed analysis of fractures and fracture networks is essential. However, common analyses on drill core and plug samples taken from such reservoirs (including hand specimen analysis, thin section analysis and laboratory porosity and permeability determination) however suffer from various problems, such as having a limited resolution, providing only 2D and no internal structure information, being destructive on the samples and/or not being representative for full fracture networks. In this paper, we therefore explore the use of an additional method – non-destructive 3D X-ray micro-Computed Tomography (μCT) – to obtain more information on such fractured samples. Seven plug-sized samples were selected from narrowly fractured rocks of the Hauptdolomit formation, taken from wellbores in the Vienna basin, Austria. These samples span a range of different fault rocks in a fault zone interpretation, from damage zone to fault core. We process the 3D μCT data in this study by a Hessian-based fracture filtering routine and can successfully extract porosity, fracture aperture, fracture density and fracture orientations – in bulk as well as locally. Additionally, thin sections made from selected plug samples provide 2D information with a much higher detail than the μCT data. Finally, gas- and water permeability measurements under confining pressure provide an important link (at least in order of magnitude) towards more realistic reservoir conditions. This study shows that 3D μCT can be applied efficiently on plug-sized samples of naturally fractured rocks, and that although there are limitations, several important parameters can be extracted. μCT can therefore be a useful addition to studies on such reservoir rocks, and provide valuable input for modelling and simulations. Also permeability experiments under confining pressure provide important additional insights. Combining these

  7. Interactive reservoir simulation

    SciTech Connect

    Regtien, J.M.M. Por, G.J.A.; Stiphout, M.T. van; Vlugt, F.F. van der

    1995-12-31

    Shell`s new Modular Reservoir Simulator (MoReS) has been equipped with a comprehensive and versatile user interface called FrontEnd. Apart from providing a user-friendly environment for interactive reservoir simulation, FrontEnd serves a software platform for other dynamic simulation and reservoir-engineering applications. It offers to all supported applications a common user interface, enables the re-use of code and reduces overall maintenance and support costs associated with the embedded applications. Because of its features, FrontEnd facilitates the transfer of research results in the form of operational software to end users. When coupled with MoReS, FrontEnd can be used for pre- and post-processing and interactive simulation. The pre-processing options allow data to be inputted by means of various OSF/Motif widgets containing a spreadsheet, text editors, dialogues and graphical input. The display of the input data as well as the post-processing of all simulation results is made possible by a variety of user-defined plot of tabular (e.g. timestep summary) and array (simulation grid) data. During a simulation user-defined plots can be displayed and edited, allowing a close inspection of the results as they are being calculated. FrontEnd has been equipped with a powerful input command language, which gives the batch user as much flexibility and control over the input as the interactive user.

  8. Next generation oil reservoir simulations

    SciTech Connect

    Joubert, W.

    1996-04-01

    This paper describes a collaborative effort between Amoco Production Company, Los Alamos National Laboratory and Cray Research Inc. to develop a next-generation massively parallel oil reservoir simulation code. The simulator, code-named Falcon, enables highly detailed simulations to be performed on a range of platforms such as the Cray T3D and T3E. The code is currently being used by Amoco to perform a sophisticated field study using multiple geostatistical realizations on a scale of 2-5 million grid blocks and 1000-2000 wells. In this paper we discuss the nature of this collaborative effort, the software design and engineering aspects of the code, parallelization experiences, and performance studies. The code will be marketed to the oil industry by a third-party independent software vendor in mid-1996.

  9. 3D visualization of port simulation.

    SciTech Connect

    Horsthemke, W. H.; Macal, C. M.; Nevins, M. R.

    1999-06-14

    Affordable and realistic three dimensional visualization technology can be applied to large scale constructive simulations such as the port simulation model, PORTSIM. These visualization tools enhance the experienced planner's ability to form mental models of how seaport operations will unfold when the simulation model is implemented and executed. They also offer unique opportunities to train new planners not only in the use of the simulation model but on the layout and design of seaports. Simulation visualization capabilities are enhanced by borrowing from work on interface design, camera control, and data presentation. Using selective fidelity, the designers of these visualization systems can reduce their time and efforts by concentrating on those features which yield the most value for their simulation. Offering the user various observational tools allows the freedom to simply watch or engage in the simulation without getting lost. Identifying the underlying infrastructure or cargo items with labels can provide useful information at the risk of some visual clutter. The PortVis visualization expands the PORTSIM user base which can benefit from the results provided by this capability, especially in strategic planning, mission rehearsal, and training. Strategic planners will immediately reap the benefits of seeing the impact of increased throughput visually without keeping track of statistical data. Mission rehearsal and training users will have an effective training tool to supplement their operational training exercises which are limited in number because of their high costs. Having another effective training modality in this visualization system allows more training to take place and more personnel to gain an understanding of seaport operations. This simulation and visualization training can be accomplished at lower cost than would be possible for the operational training exercises alone. The application of PORTSIM and PortVis will lead to more efficient

  10. 3D simulation for falling papers

    NASA Astrophysics Data System (ADS)

    Aoki, Takayuki

    2001-12-01

    The combination of IDO (Interpolated Differential Operator) scheme, Cut Cell technique, and overlapping grid method make it possible to simulate the falling process of papers. We have the result of the falling with fluttering trajectory for a certain initial angle of the paper, and the fluttering mechanism becomes clear. It is shown that the simulation is applicable to the phenomena of falling leaves with complex shape.

  11. Interactive 3D display simulator for autostereoscopic smart pad

    NASA Astrophysics Data System (ADS)

    Choe, Yeong-Seon; Lee, Ho-Dong; Park, Min-Chul; Son, Jung-Young; Park, Gwi-Tae

    2012-06-01

    There is growing interest of displaying 3D images on a smart pad for entertainments and information services. Designing and realizing various types of 3D displays on the smart pad is not easy for costs and given time. Software simulation can be an alternative method to save and shorten the development. In this paper, we propose a 3D display simulator for autostereoscopic smart pad. It simulates light intensity of each view and crosstalk for smart pad display panels. Designers of 3D display for smart pad can interactively simulate many kinds of autostereoscopic displays interactively by changing parameters required for panel design. Crosstalk to reduce leakage of one eye's image into the image of the other eye, and light intensity for computing visual comfort zone are important factors in designing autostereoscopic display for smart pad. Interaction enables intuitive designs. This paper describes an interactive 3D display simulator for autostereoscopic smart pad.

  12. Surviving sepsis--a 3D integrative educational simulator.

    PubMed

    Ježek, Filip; Tribula, Martin; Kulhánek, Tomáš; Mateják, Marek; Privitzer, Pavol; Šilar, Jan; Kofránek, Jiří; Lhotská, Lenka

    2015-08-01

    Computer technology offers greater educational possibilities, notably simulation and virtual reality. This paper presents a technology which serves to integrate multiple modalities, namely 3D virtual reality, node-based simulator, Physiomodel explorer and explanatory physiological simulators employing Modelica language and Unity3D platform. This emerging tool chain should allow the authors to concentrate more on educational content instead of application development. The technology is demonstrated through Surviving sepsis educational scenario, targeted on Microsoft Windows Store platform.

  13. Improving Geologic and Engineering Models of Midcontinent Fracture and Karst-Modified Reservoirs Using New 3-D Seismic Attributes

    SciTech Connect

    Susan Nissen; Saibal Bhattacharya; W. Lynn Watney; John Doveton

    2009-03-31

    Our project goal was to develop innovative seismic-based workflows for the incremental recovery of oil from karst-modified reservoirs within the onshore continental United States. Specific project objectives were: (1) to calibrate new multi-trace seismic attributes (volumetric curvature, in particular) for improved imaging of karst-modified reservoirs, (2) to develop attribute-based, cost-effective workflows to better characterize karst-modified carbonate reservoirs and fracture systems, and (3) to improve accuracy and predictiveness of resulting geomodels and reservoir simulations. In order to develop our workflows and validate our techniques, we conducted integrated studies of five karst-modified reservoirs in west Texas, Colorado, and Kansas. Our studies show that 3-D seismic volumetric curvature attributes have the ability to re-veal previously unknown features or provide enhanced visibility of karst and fracture features compared with other seismic analysis methods. Using these attributes, we recognize collapse features, solution-enlarged fractures, and geomorphologies that appear to be related to mature, cockpit landscapes. In four of our reservoir studies, volumetric curvature attributes appear to delineate reservoir compartment boundaries that impact production. The presence of these compartment boundaries was corroborated by reservoir simulations in two of the study areas. Based on our study results, we conclude that volumetric curvature attributes are valuable tools for mapping compartment boundaries in fracture- and karst-modified reservoirs, and we propose a best practices workflow for incorporating these attributes into reservoir characterization. When properly calibrated with geological and production data, these attributes can be used to predict the locations and sizes of undrained reservoir compartments. Technology transfer of our project work has been accomplished through presentations at professional society meetings, peer-reviewed publications

  14. 3D simulation for solitons used in optical fibers

    NASA Astrophysics Data System (ADS)

    Vasile, F.; Tebeica, C. M.; Schiopu, P.; Vladescu, M.

    2016-12-01

    In this paper is described 3D simulation for solitions used in optical fibers. In the scientific works is started from nonlinear propagation equation and the solitons represents its solutions. This paper presents the simulation of the fundamental soliton in 3D together with simulation of the second order soliton in 3D. These simulations help in the study of the optical fibers for long distances and in the interactions between the solitons. This study helps the understanding of the nonlinear propagation equation and for nonlinear waves. These 3D simulations are obtained using MATLAB programming language, and we can observe fundamental difference between the soliton and the second order/higher order soliton and in their evolution.

  15. Determining the 3-D fracture structure in the Geysers geothermal reservoir

    SciTech Connect

    Sammis, Charles G.; Linji An; Iraj Ershaghi

    1992-01-01

    The bulk of the steam at the Geysers geothermal field is produced from fractures in a relatively impermeable graywacke massif which has been heated by an underlying felsite intrusion. The largest of these fractures are steeply dipping right lateral strike-slip faults which are subparallel to the NW striking Collayomi and Mercuryville faults which form the NE and SW boundaries of the known reservoir. Where the graywacke source rock outcrops at the surface it is highly sheared and fractured over a wide range of scale lengths. Boreholes drilled into the reservoir rock encounter distinct ''steam entries'' at which the well head pressure jumps from a few to more than one hundred psi. This observation that steam is produced from a relatively small number of major fractures has persuaded some analysts to use the Warren and Root (1963) dual porosity model for reservoir simulation purposes. The largest fractures in this model are arranged in a regular 3-D array which partitions the reservoir into cubic ''matrix'' blocks. The net storage and transport contribution of all the smaller fractures in the reservoir are lumped into average values for the porosity and permeability of these matrix blocks which then feed the large fractures. Recent improvements of this model largely focus on a more accurate representation of the transport from matrix to fractures (e.g. Pruess et al., 1983; Ziminerman et al., 1992), but the basic geometry is rarely questioned. However, it has long been recognized that steam entries often occur in clusters separated by large intervals of unproductive rock (Thomas et al., 1981). Such clustering of fixtures at all scale lengths is one characteristic of self-similar distributions in which the fracture distribution is scale-independent. Recent studies of the geometry of fracture networks both in the laboratory and in the field are finding that such patterns are self-similar and can be best described using fractal geometry. Theoretical simulations of

  16. Using 3D visualization and seismic attributes to improve structural and stratigraphic resolution of reservoirs

    SciTech Connect

    Kerr, J. ); Jones, G.L. )

    1996-01-01

    Recent advances in hardware and software have given the interpreter and engineer new ways to view 3D seismic data and well bore information. Recent papers have also highlighted the use of various statistics and seismic attributes. By combining new 3D rendering technologies with recent trends in seismic analysis, the interpreter can improve the structural and stratigraphic resolution of hydrocarbon reservoirs. This paper gives several examples using 3D visualization to better define both the structural and stratigraphic aspects of several different structural types from around the world. Statistics, 3D visualization techniques and rapid animation are used to show complex faulting and detailed channel systems. These systems would be difficult to map using either 2D or 3D data with conventional interpretation techniques.

  17. Using 3D visualization and seismic attributes to improve structural and stratigraphic resolution of reservoirs

    SciTech Connect

    Kerr, J.; Jones, G.L.

    1996-12-31

    Recent advances in hardware and software have given the interpreter and engineer new ways to view 3D seismic data and well bore information. Recent papers have also highlighted the use of various statistics and seismic attributes. By combining new 3D rendering technologies with recent trends in seismic analysis, the interpreter can improve the structural and stratigraphic resolution of hydrocarbon reservoirs. This paper gives several examples using 3D visualization to better define both the structural and stratigraphic aspects of several different structural types from around the world. Statistics, 3D visualization techniques and rapid animation are used to show complex faulting and detailed channel systems. These systems would be difficult to map using either 2D or 3D data with conventional interpretation techniques.

  18. Design of 3D simulation engine for oilfield safety training

    NASA Astrophysics Data System (ADS)

    Li, Hua-Ming; Kang, Bao-Sheng

    2015-03-01

    Aiming at the demand for rapid custom development of 3D simulation system for oilfield safety training, this paper designs and implements a 3D simulation engine based on script-driven method, multi-layer structure, pre-defined entity objects and high-level tools such as scene editor, script editor, program loader. A scripting language been defined to control the system's progress, events and operating results. Training teacher can use this engine to edit 3D virtual scenes, set the properties of entity objects, define the logic script of task, and produce a 3D simulation training system without any skills of programming. Through expanding entity class, this engine can be quickly applied to other virtual training areas.

  19. An Evaluative Review of Simulated Dynamic Smart 3d Objects

    NASA Astrophysics Data System (ADS)

    Romeijn, H.; Sheth, F.; Pettit, C. J.

    2012-07-01

    Three-dimensional (3D) modelling of plants can be an asset for creating agricultural based visualisation products. The continuum of 3D plants models ranges from static to dynamic objects, also known as smart 3D objects. There is an increasing requirement for smarter simulated 3D objects that are attributed mathematically and/or from biological inputs. A systematic approach to plant simulation offers significant advantages to applications in agricultural research, particularly in simulating plant behaviour and the influences of external environmental factors. This approach of 3D plant object visualisation is primarily evident from the visualisation of plants using photographed billboarded images, to more advanced procedural models that come closer to simulating realistic virtual plants. However, few programs model physical reactions of plants to external factors and even fewer are able to grow plants based on mathematical and/or biological parameters. In this paper, we undertake an evaluation of plant-based object simulation programs currently available, with a focus upon the components and techniques involved in producing these objects. Through an analytical review process we consider the strengths and weaknesses of several program packages, the features and use of these programs and the possible opportunities in deploying these for creating smart 3D plant-based objects to support agricultural research and natural resource management. In creating smart 3D objects the model needs to be informed by both plant physiology and phenology. Expert knowledge will frame the parameters and procedures that will attribute the object and allow the simulation of dynamic virtual plants. Ultimately, biologically smart 3D virtual plants that react to changes within an environment could be an effective medium to visually represent landscapes and communicate land management scenarios and practices to planners and decision-makers.

  20. Petroleum reservoir simulation in a virtual environment

    SciTech Connect

    Jacobsen, J.S.; Bethel, E.W.; Datta-Gupta, A.; Holland, P.J.

    1995-12-31

    In this paper, the authors describe an approach to combining a reservoir simulation with 3-D visualization and virtual reality technology. Their prototype VR/visualization system minimizes human-machine interface barriers and provides enhanced control over the simulation, thereby maximizing scientific judgment and use of intuition. They illustrate the practical advantage of using the VR/visualization prototype system in reservoir engineering by visualizing the results of a waterflood in an oil field with a three-dimensional, spatially correlated heterogeneous permeability field.

  1. Preliminary investigations on 3D PIC simulation of DPHC structure using NEPTUNE3D code

    NASA Astrophysics Data System (ADS)

    Zhao, Hailong; Dong, Ye; Zhou, Haijing; Zou, Wenkang; Wang, Qiang

    2016-10-01

    Cubic region (34cm × 34cm × 18cm) including the double post-hole convolute (DPHC) structure was chosen to perform a series of fully 3D PIC simulations using NEPTUNE3D codes, massive data ( 200GB) could be acquired and solved in less than 5 hours. Cold-chamber tests were performed during which only cathode electron emission was considered without temperature rise or ion emission, current loss efficiency was estimated by comparisons between output magnetic field profiles with or without electron emission. PIC simulation results showed three stages of current transforming process with election emission in DPHC structure, the maximum ( 20%) current loss was 437kA at 15ns, while only 0.46% 0.48% was lost when driving current reached its peak. DPHC structure proved valuable functions during energy transform process in PTS facility, and NEPTUNE3D provided tools to explore this sophisticated physics. Project supported by the National Natural Science Foundation of China, Grant No. 11571293, 11505172.

  2. A probabilistic approach to jointly integrate 3D/4D seismic, production data and geological information for building reservoir models

    NASA Astrophysics Data System (ADS)

    Castro, Scarlet A.

    Reservoir modeling aims at understanding static and dynamic components of the reservoir in order to make decisions about future surface operations. The practice of reservoir modeling calls for the integration of expertise from different disciplines, as well as the in tegration of a wide variety of data: geological data, (core data, well-logs, etc.), production data (fluid rates or volumes, pressure data, etc.), and geophysical data (3D seismic data). Although a single 3D seismic survey is the most common geophysical data available for most reservoirs, a suite of several 3D seismic surveys (4D seismic data) acquired for monitoring production can be available for mature reservoirs. The main contribution of this dissertation is to incorporate 4D seismic data within the reservoir modeling workflow while honoring all other available data. This dissertation proposes two general approaches to include 4D seismic data into the reservoir modeling workflow. The Probabilistic Data Integration approach (PDI), which consists of modeling the information content of 4D seismic through a spatial probability of facies occurrence; and the Forward Modeling (FM) approach, which consists of matching 4D seismic along with production data. The FM approach requires forward modeling the 4D seismic response, which requires to downscale the flow simulation response. This dissertation introduces a novel dynamic downscaling method that takes into account both static information (high-resolution per meability field) and dynamic information in the form of coarsened fluxes and saturations (flow simulation on the coarsened grid). The two proposed approaches (PDI and FM approaches) are applied to a prominent field in the North Sea, to model the channel facies of a fluvial reservoir. The PDI approach constrained the reservoir model to the spatial probability of facies occurrence (obtained from a calibration between well-log and 4D seismic data) as well as other static data while satisfactorily history

  3. 3D Ultrasonic Wave Simulations for Structural Health Monitoring

    NASA Technical Reports Server (NTRS)

    Campbell, Leckey Cara A/; Miler, Corey A.; Hinders, Mark K.

    2011-01-01

    Structural health monitoring (SHM) for the detection of damage in aerospace materials is an important area of research at NASA. Ultrasonic guided Lamb waves are a promising SHM damage detection technique since the waves can propagate long distances. For complicated flaw geometries experimental signals can be difficult to interpret. High performance computing can now handle full 3-dimensional (3D) simulations of elastic wave propagation in materials. We have developed and implemented parallel 3D elastodynamic finite integration technique (3D EFIT) code to investigate ultrasound scattering from flaws in materials. EFIT results have been compared to experimental data and the simulations provide unique insight into details of the wave behavior. This type of insight is useful for developing optimized experimental SHM techniques. 3D EFIT can also be expanded to model wave propagation and scattering in anisotropic composite materials.

  4. M3D project for simulation studies of plasmas

    SciTech Connect

    Park, W.; Belova, E.V.; Fu, G.Y.; Strauss, H.R.; Sugiyama, L.E.

    1998-12-31

    The M3D (Multi-level 3D) project carries out simulation studies of plasmas of various regimes using multi-levels of physics, geometry, and mesh schemes in one code package. This paper and papers by Strauss, Sugiyama, and Belova in this workshop describe the project, and present examples of current applications. The currently available physics models of the M3D project are MHD, two-fluids, gyrokinetic hot particle/MHD hybrid, and gyrokinetic particle ion/two-fluid hybrid models. The code can be run with both structured and unstructured meshes.

  5. Geothermal Project Den Haag - 3-D models for temperature prediction and reservoir characterization

    NASA Astrophysics Data System (ADS)

    Mottaghy, D.; Pechnig, R.; Willemsen, G.; Simmelink, H. J.; Vandeweijer, V.

    2009-04-01

    In the framework of the "Den Haag Zuidwest" geothermal district heating system a deep geothermal installation is projected. The target horizon of the planned doublet is the "Delft sandstone" which has been extensively explored for oil- and gas reservoirs in the last century. In the target area, this upper Jurassic sandstone layer is found at a depth of about 2300 m with an average thickness of about 50 m. The study presented here focuses on the prediction of reservoir temperatures and production behavior which is crucial for planning a deep geothermal installation. In the first phase, the main objective was to find out whether there is a significant influence of the 3-dimensional structures of anticlines and synclines on the temperature field, which could cause formation temperatures deviating from the predicted extrapolated temperature data from oil and gas exploration wells. To this end a regional model was set up as a basis for steady state numerical simulations. Since representative input parameters are decisive for reliable model results, all available information was compiled: a) the subsurface geometry, depth and thickness of the stratigraphic layers known from seismic data sets 2) borehole geophysical data and c) geological and petrographical information from exploration wells. In addition 50 cuttings samples were taken from two selected key wells in order to provide direct information on thermal properties of the underlying strata. Thermal conductivity and rock matrix density were measured in the laboratory. These data were combined with a petrophysical log analysis (Gamma Ray, Sonic, Density and Resistivity), which resulted in continuous profiles of porosity, effective thermal conductivity and radiogenetic heat production. These profiles allowed to asses in detail the variability of the petrophysical properties with depth and to check for lateral changes between the wells. All this data entered the numerical simulations which were performed by a 3-D

  6. Comparison of Actual Surgical Outcomes and 3D Surgical Simulations

    PubMed Central

    Tucker, Scott; Cevidanes, Lucia; Styner, Martin; Kim, Hyungmin; Reyes, Mauricio; Proffit, William; Turvey, Timothy

    2009-01-01

    Purpose The advent of imaging software programs have proved to be useful for diagnosis, treatment planning, and outcome measurement, but precision of 3D surgical simulation still needs to be tested. This study was conducted to determine if the virtual surgery performed on 3D models constructed from Cone-beam CT (CBCT) can correctly simulate the actual surgical outcome and to validate the ability of this emerging technology to recreate the orthognathic surgery hard tissue movements in 3 translational and 3 rotational planes of space. Methods Construction of pre- and post-surgery 3D models from CBCTs of 14 patients who had combined maxillary advancement and mandibular setback surgery and 6 patients who had one-piece maxillary advancement surgery was performed. The post-surgery and virtually simulated surgery 3D models were registered at the cranial base to quantify differences between simulated and actual surgery models. Hotelling T-test were used to assess the differences between simulated and actual surgical outcomes. Results For all anatomic regions of interest, there was no statistically significant difference between the simulated and the actual surgical models. The right lateral ramus was the only region that showed a statistically significant, but small difference when comparing two- and one-jaw surgeries. Conclusions Virtual surgical methods were reliably reproduced, oral surgery residents could benefit from virtual surgical training, and computer simulation has the potential to increase predictability in the operating room. PMID:20591553

  7. Development of a Simulation Tool for 3D Braiding Architectures

    NASA Astrophysics Data System (ADS)

    Tolosana, N.; Lomov, S.; Stüve, J.; Miravete, A.

    2007-04-01

    The usage of textile technologies for composites is widely extended in aeronautic applications. They provide an improvement on mechanical properties in the thickness direction, and offer some other advantages in comparison with prepreg technology regarding production. Nowadays 3D-braiding machines do not only enable the production of solid profiles but enable also the production of complex near-net-shape reinforcement structures with changing cross section geometry. In order to attain a full understanding on structure of 3d braids to be able to predict mechanical properties, simulation tools including machine operation are needed. A simulation tool is being developed as a part of the EU project "Integrated Tool for Simulation of Textile Composites", starting from 3d braiding machinery description and operation. This information is required to reproduce yarn paths in the produced unit cell, based on the interlacing pattern of the braid.

  8. 3d visualization of atomistic simulations on every desktop

    NASA Astrophysics Data System (ADS)

    Peled, Dan; Silverman, Amihai; Adler, Joan

    2013-08-01

    Once upon a time, after making simulations, one had to go to a visualization center with fancy SGI machines to run a GL visualization and make a movie. More recently, OpenGL and its mesa clone have let us create 3D on simple desktops (or laptops), whether or not a Z-buffer card is present. Today, 3D a la Avatar is a commodity technique, presented in cinemas and sold for home TV. However, only a few special research centers have systems large enough for entire classes to view 3D, or special immersive facilities like visualization CAVEs or walls, and not everyone finds 3D immersion easy to view. For maximum physics with minimum effort a 3D system must come to each researcher and student. So how do we create 3D visualization cheaply on every desktop for atomistic simulations? After several months of attempts to select commodity equipment for a whole room system, we selected an approach that goes back a long time, even predating GL. The old concept of anaglyphic stereo relies on two images, slightly displaced, and viewed through colored glasses, or two squares of cellophane from a regular screen/projector or poster. We have added this capability to our AViz atomistic visualization code in its new, 6.1 version, which is RedHat, CentOS and Ubuntu compatible. Examples using data from our own research and that of other groups will be given.

  9. 3D Fiber Orientation Simulation for Plastic Injection Molding

    NASA Astrophysics Data System (ADS)

    Lin, Baojiu; Jin, Xiaoshi; Zheng, Rong; Costa, Franco S.; Fan, Zhiliang

    2004-06-01

    Glass fiber reinforced polymer is widely used in the products made using injection molding processing. The distribution of fiber orientation inside plastic parts has direct effects on quality of molded parts. Using computer simulation to predict fiber orientation distribution is one of most efficient ways to assist engineers to do warpage analysis and to find a good design solution to produce high quality plastic parts. Fiber orientation simulation software based on 2-1/2D (midplane /Dual domain mesh) techniques has been used in industry for a decade. However, the 2-1/2D technique is based on the planar Hele-Shaw approximation and it is not suitable when the geometry has complex three-dimensional features which cannot be well approximated by 2D shells. Recently, a full 3D simulation software for fiber orientation has been developed and integrated into Moldflow Plastics Insight 3D simulation software. The theory for this new 3D fiber orientation calculation module is described in this paper. Several examples are also presented to show the benefit in using 3D fiber orientation simulation.

  10. Geological characterization of Italian reservoirs and numerical 3D modelling of CO2 storage scenarios into saline aquifers

    NASA Astrophysics Data System (ADS)

    Beretta, S.; Moia, F.; Guandalini, R.; Cappelletti, F.

    2012-04-01

    The research activities carried out by the Environment and Sustainable Development Department of RSE S.p.A. aim to evaluate the feasibility of CO2 geological sequestration in Italy, with particular reference to the storage into saline aquifers. The identification and geological characterization of the Italian potential storage sites, together with the study of the temporal and spatial evolution of the CO2 plume within the caprock-reservoir system, are performed using different modelling tools available in the Integrated Analysis Modelling System (SIAM) entirely powered in RSE. The numerical modelling approach is the only one that allows to investigate the behaviour of the injected CO2 regarding the fluid dynamic, geochemical and geomechanical aspects and effects due to its spread, in order to verify the safety of the process. The SIAM tools allow: - Selection of potential Italian storage sites through geological and geophysical data collected in the GIS-CO2 web database; - Characterization of caprock and aquifer parameters, seismic risk and environmental link for the selected site; - Creation of the 3D simulation model for the selected domain, using the modeller METHODRdS powered by RSE and the mesh generator GMSH; - Simulation of the injection and the displacement of CO2: multiphase fluid 3D dynamics is based on the modified version of TOUGH2 model; - Evaluation of geochemical reaction effects; - Evaluation of geomechanic effects, using the coupled 3D CANT-SD finite elements code; - Detailed local analysis through the use of open source auxiliary tools, such as SHEMAT and FEHM. - 3D graphic analysis of the results. These numerical tools have been successfully used for simulating the injection and the spread of CO2 into several real Italian reservoirs and have allowed to achieve accurate results in terms of effective storage capacity and safety analysis. The 3D geological models represent the high geological complexity of the Italian subsoil, where reservoirs are

  11. 3D characterization of the fracture network in a deformed chalk reservoir analogue: The Lagerdorf case

    SciTech Connect

    Koestler, A.G.; Reksten, K.

    1994-12-31

    Quantitative descriptions of the 3D fracture networks in terms of connectivity, fracture types, fracture surface roughness and flow characteristics are necessary for reservoir evaluation, management, and enhanced oil recovery programs of fractured reservoirs. For a period of 2 years, a research project focused on an analogue to fractured chalk reservoirs excellently exposed near Laegerdorf, NW Germany. Upper Cretaceous chalk has been uplifted and deformed by an underlying salt diapir, and is now exploited for the cement industry. In the production wall of a quarry, the fracture network of the deformed chalk was characterized and mapped at different scales. The wall was scraped off as chalk exploitation proceeded, continuously revealing new sections through the faulted and fractured chalk body. A 230 m long part of the 35m high production wall was investigated during its recess of 25m. The large amount of fracture data were analyzed with respect to parameters such as fracture density distribution, orientation- and length distribution, and in terms of the representativity of data sets collected from restricted rock volumes. This 3D description and analysis of a fracture network revealed quantitative generic parameters of importance for modeling chalk reservoirs with less data and lower data quality.

  12. 3D stress field simulation for Greater Munich, Germany

    NASA Astrophysics Data System (ADS)

    Ziegler, Moritz; Heidbach, Oliver; Reinecker, John; Przybycin, Anna Maria; Scheck-Wenderoth, Magdalena

    2016-04-01

    Geotechnical applications such as tunneling, storage of waste, wellbore planning, or reservoir engineering requires detailed 3D information on the rock properties and behavior of the continuum. One of the key parameters is the contemporary crustal in-situ stress state. However, generally the availability of stress data on reservoir scale is scarce or no data exists at all. Furthermore, stress data is often limited to the orientation of the maximum horizontal stress. Hence, geomechanical-numerical modelling provides an approximation of a continuous description of the 3D in-situ stress state. We present a model workflow that shows (1) how to calibrate a regional scale model of Greater Munich with stress orientations and magnitudes mainly from borehole data and (2) how to derive from the regional model boundary conditions for a local high-resolution model of a geothermal reservoir site. This approach using two models is an alternative to the required trade-off between resolution, computational cost and a sufficient number of calibration data which is otherwise inevitable for a single model. The incorporated 3D geological models contain the topography from a digital elevation model and 6 stratigraphic units with different elasto-plastic rock properties. The local model mimics the area of a planned reservoir and its resolution is significantly higher than in the regional model and down to 10 m near the planned borehole trajectories using 21×106 tetrahedron finite elements with linear approximation functions. The uncertainties of the calibrated regional model are large since no information on the magnitude of the maximum horizontal stress is available. Even in the entire Greater Munich area only two reliable leak-off tests that deliver the magnitude of the minimum horizontal stress could be used. These uncertainties are transferred also to the local model. Hence we also show how to quantify for the workflow in general the systematic uncertainties and discuss

  13. Advancing New 3D Seismic Interpretation Methods for Exploration and Development of Fractured Tight Gas Reservoirs

    SciTech Connect

    James Reeves

    2005-01-31

    In a study funded by the U.S. Department of Energy and GeoSpectrum, Inc., new P-wave 3D seismic interpretation methods to characterize fractured gas reservoirs are developed. A data driven exploratory approach is used to determine empirical relationships for reservoir properties. Fractures are predicted using seismic lineament mapping through a series of horizon and time slices in the reservoir zone. A seismic lineament is a linear feature seen in a slice through the seismic volume that has negligible vertical offset. We interpret that in regions of high seismic lineament density there is a greater likelihood of fractured reservoir. Seismic AVO attributes are developed to map brittle reservoir rock (low clay) and gas content. Brittle rocks are interpreted to be more fractured when seismic lineaments are present. The most important attribute developed in this study is the gas sensitive phase gradient (a new AVO attribute), as reservoir fractures may provide a plumbing system for both water and gas. Success is obtained when economic gas and oil discoveries are found. In a gas field previously plagued with poor drilling results, four new wells were spotted using the new methodology and recently drilled. The wells have estimated best of 12-months production indicators of 2106, 1652, 941, and 227 MCFGPD. The latter well was drilled in a region of swarming seismic lineaments but has poor gas sensitive phase gradient (AVO) and clay volume attributes. GeoSpectrum advised the unit operators that this location did not appear to have significant Lower Dakota gas before the well was drilled. The other three wells are considered good wells in this part of the basin and among the best wells in the area. These new drilling results have nearly doubled the gas production and the value of the field. The interpretation method is ready for commercialization and gas exploration and development. The new technology is adaptable to conventional lower cost 3D seismic surveys.

  14. Cooperative 3D Path Optimization (C3PO) Simulation

    DTIC Science & Technology

    2015-11-10

    knowledge, the group would elect a leader, plan a path using Rapidly-Exploring Random Trees (RRTs), and move to the goal using Artificial Potential...Exploring Random Trees (RRTs), and move to the goal using Artificial Potential Field. The simulation was created in the MASON multi-agent simulation...affect the ability to plan paths quickly. 15. SUBJECT TERMS Cooperative 3D Path Optimization Planning dimension swarm RRT artificial potential field

  15. Flexible simulation framework to couple processes in complex 3D models for subsurface utilization assessment

    NASA Astrophysics Data System (ADS)

    Kempka, Thomas; Nakaten, Benjamin; De Lucia, Marco; Nakaten, Natalie; Otto, Christopher; Pohl, Maik; Tillner, Elena; Kühn, Michael

    2016-04-01

    Utilization of the geological subsurface for production and storage of hydrocarbons, chemical energy and heat as well as for waste disposal requires the quantification and mitigation of environmental impacts as well as the improvement of georesources utilization in terms of efficiency and sustainability. The development of tools for coupled process simulations is essential to tackle these challenges, since reliable assessments are only feasible by integrative numerical computations. Coupled processes at reservoir to regional scale determine the behaviour of reservoirs, faults and caprocks, generally demanding for complex 3D geological models to be considered besides available monitoring and experimenting data in coupled numerical simulations. We have been developing a flexible numerical simulation framework that provides efficient workflows for integrating the required data and software packages to carry out coupled process simulations considering, e.g., multiphase fluid flow, geomechanics, geochemistry and heat. Simulation results are stored in structured data formats to allow for an integrated 3D visualization and result interpretation as well as data archiving and its provision to collaborators. The main benefits in using the flexible simulation framework are the integration of data geological and grid data from any third party software package as well as data export to generic 3D visualization tools and archiving formats. The coupling of the required process simulators in time and space is feasible, while different spatial dimensions in the coupled simulations can be integrated, e.g., 0D batch with 3D dynamic simulations. User interaction is established via high-level programming languages, while computational efficiency is achieved by using low-level programming languages. We present three case studies on the assessment of geological subsurface utilization based on different process coupling approaches and numerical simulations.

  16. 3-D General Relativistic MHD Simulations of Generating Jets

    NASA Astrophysics Data System (ADS)

    Nishikawa, K.-I.; Koide, S.; Shibata, K.; Kudoh, T.; Frank, J.; Sol, H.

    1999-05-01

    Koide et al have investigated the dynamics of an accretion disk initially threaded by a uniform poloidal magnetic field in a non-rotating corona (either in a steady-state infalling state or in hydrostatic equilibrium) around a non-rotating black hole using a 3-D GRMHD with the ``axisymmetry'' along the z-direction. Magnetic field is tightly twisted by the rotation of the disk, and plasmas in the shocked region of the disk are accelerated by J x B force to form bipolar relativistic jets. In order to investigate variabilities of generated relativistic jets and magnetic field structure inside jets, we have performed calculations using the 3-D GRMHD code on a full 3-dimensional system. We will investigate how the third dimension affects the global disk dynamics. 3-D RMHD simulations wil be also performed to investigate the dynamics of a jet with a helical mangetic field in it.

  17. VISRAD, 3-D Target Design and Radiation Simulation Code

    NASA Astrophysics Data System (ADS)

    Golovkin, Igor; Macfarlane, Joseph; Golovkina, Viktoriya

    2016-10-01

    The 3-D view factor code VISRAD is widely used in designing HEDP experiments at major laser and pulsed-power facilities, including NIF, OMEGA, OMEGA-EP, ORION, LMJ, Z, and PLX. It simulates target designs by generating a 3-D grid of surface elements, utilizing a variety of 3-D primitives and surface removal algorithms, and can be used to compute the radiation flux throughout the surface element grid by computing element-to-element view factors and solving power balance equations. Target set-up and beam pointing are facilitated by allowing users to specify positions and angular orientations using a variety of coordinates systems (e.g., that of any laser beam, target component, or diagnostic port). Analytic modeling for laser beam spatial profiles for OMEGA DPPs and NIF CPPs is used to compute laser intensity profiles throughout the grid of surface elements. We will discuss recent improvements to the software package and plans for future developments.

  18. Areal 3-D seismic technique for reservoir delineation: Case history from offshore Niger Delta

    SciTech Connect

    Idowu, A.O. )

    1993-02-01

    In the 1950s, early exploration period in the Niger Delta witnessed the use of 2-D (two dimensional) seismic reflection method which adequate for imaging large subsurface geologic features including growth faulting and roll-over anticlines. This technique involves the Common-Depth-Point method (CDP) which acquires a plane of seismic information in distance along the surface and in time into the geological section, and is used to improve the signal-to-noise (S/N) ratio, to remove multiples and consequently give a representation of the subsurface particularly if the data are collected up- or downdip. By mid-1980s, the obvious geological structures have, in general, been discovered and it became necessary to adopt a more sophisticated technique such as the 3-D (three dimensional) seismic method to delineate more subtle reservoirs and resolve complex fault patterns in order to aid exploration as well as facilitate efficient field development. The case history discussed in this paper involves the use of areal 3-D seismic method for delineating the reservoir characterization of the O-field located in a shallow water area of the western Niger Delta. The areal 3-D seismic technique is superior to the earlier CDP method in that a cube of seismic data can be collected in two dimensions in space and one in time by a variety of techniques including the swath seismic shooting pattern adopted for gathering the 3-D data for the O-field's reservoir which involves the line of sources. The objective is to adequately sample the subsurface so that changes in various parameters such as the amplitude phase or power in the siesmic signal or velocity of propagation can be mapped areally and interpreted as an indication of changes in the physical properties of the rock matrix.

  19. 3D finite element simulations of high velocity projectile impact

    NASA Astrophysics Data System (ADS)

    Ožbolt, Joško; İrhan, Barış; Ruta, Daniela

    2015-09-01

    An explicit three-dimensional (3D) finite element (FE) code is developed for the simulation of high velocity impact and fragmentation events. The rate sensitive microplane material model, which accounts for large deformations and rate effects, is used as a constitutive law. In the code large deformation frictional contact is treated by forward incremental Lagrange multiplier method. To handle highly distorted and damaged elements the approach based on the element deletion is employed. The code is then used in 3D FE simulations of high velocity projectile impact. The results of the numerical simulations are evaluated and compared with experimental results. It is shown that it realistically predicts failure mode and exit velocities for different geometries of plain concrete slab. Moreover, the importance of some relevant parameters, such as contact friction, rate sensitivity, bulk viscosity and deletion criteria are addressed.

  20. 3D simulation of coaxial carbon nanotube field effect transistor

    NASA Astrophysics Data System (ADS)

    Hien, Dinh Sy; Thi Luong, Nguyen; Tuan, Thi Tran Anh; Viet Nga, Dinh

    2009-09-01

    We provide a model of coaxial CNTFET geometry. Coaxial devices are of special interest because their geometry allows for better electrostatics. We explore the possibilities of using non-equilibrium Green's function method to get I-V characteristics for CNTFETs. This simulator also includes a graphic user interface (GUI) of Matlab. We review the capabilities of the simulator, and give examples of typical CNTFET's 3D simulations (current-voltage characteristics are a function of parameters such as the length of CNTFET, gate thickness and temperature). The obtained I-V characteristics of the CNTFET are also presented by analytical equations.

  1. SMALL, GEOLOGICALLY COMPLEX RESERVOIRS CAN BENEFIT FROM RESERVOIR SIMULATION

    SciTech Connect

    Richard E. Bennett

    2002-06-24

    on, and an expansion of the scope of the reservoir simulation and modeling effort was initiated, using DOE's BOAST98 (a visual, dynamic, interactive update of BOAST3), 3D, black oil reservoir simulation package as the basis for developing the reservoir model. Reservoir characterization, modeling, and reservoir simulation resulted in a significant change in the depletion strategy. Information from the reservoir characterization and modeling effort indicate that in-fill drilling and relying on natural water influx from the aquifer could increase remaining reserves by 125,000 barrels of oil per well, and that up to 10 infill wells could be drilled in the field. Through this scenario, field production could be increased two to three times over the current 65 bopd. Based on the results of the study, permits have been applied for to drill a directional infill well to encounter the productive zone at a high angle in order to maximize the amount of pay and reservoirs encountered.

  2. Comparative visual analysis of 3D urban wind simulations

    NASA Astrophysics Data System (ADS)

    Röber, Niklas; Salim, Mohamed; Grawe, David; Leitl, Bernd; Böttinger, Michael; Schlünzen, Heinke

    2016-04-01

    Climate simulations are conducted in large quantity for a variety of different applications. Many of these simulations focus on global developments and study the Earth's climate system using a coupled atmosphere ocean model. Other simulations are performed on much smaller regional scales, to study very small fine grained climatic effects. These microscale climate simulations pose similar, yet also different, challenges for the visualization and the analysis of the simulation data. Modern interactive visualization and data analysis techniques are very powerful tools to assist the researcher in answering and communicating complex research questions. This presentation discusses comparative visualization for several different wind simulations, which were created using the microscale climate model MITRAS. The simulations differ in wind direction and speed, but are all centered on the same simulation domain: An area of Hamburg-Wilhelmsburg that hosted the IGA/IBA exhibition in 2013. The experiments contain a scenario case to analyze the effects of single buildings, as well as examine the impact of the Coriolis force within the simulation. The scenario case is additionally compared with real measurements from a wind tunnel experiment to ascertain the accuracy of the simulation and the model itself. We also compare different approaches for tree modeling and evaluate the stability of the model. In this presentation, we describe not only our workflow to efficiently and effectively visualize microscale climate simulation data using common 3D visualization and data analysis techniques, but also discuss how to compare variations of a simulation and how to highlight the subtle differences in between them. For the visualizations we use a range of different 3D tools that feature techniques for statistical data analysis, data selection, as well as linking and brushing.

  3. Analysis of fracture networks in a reservoir dolomite by 3D micro-imaging

    NASA Astrophysics Data System (ADS)

    Voorn, Maarten; Hoyer, Stefan; Exner, Ulrike; Reuschlé, Thierry

    2013-04-01

    Narrow fractures in reservoir rocks can be of great importance when determining the hydrocarbon potential of such a reservoir. Such fractures can contribute significantly to - or even be dominant for - the porosity and permeability characteristics of such rocks. Investigating these narrow fractures is therefore important, but not always trivial. Standard laboratory measurements on sample plugs from a reservoir are not always suitable for fractured rocks. Thin section analysis can provide very important information, but mostly only in 2D. Also other sources of information have major drawbacks, such as FMI (Formation Micro-Imager) during coring (insufficient resolution) and hand specimen analysis (no internal information). 3D imaging of reservoir rock samples is a good alternative and extension to the methods mentioned above. The 3D information is in our case obtained by X-ray Micro-Computed Tomography (µCT) imaging. Our used samples are 2 and 3 cm diameter plugs of a narrowly fractured (apertures generally <200 µm) reservoir dolomite (Hauptdolomit formation) from below the Vienna Basin, Austria. µCT has the large advantage of being non-destructive to the samples, and with the chosen sample sizes and settings, the sample rocks and fractures can be imaged with sufficient quality at sufficient resolution. After imaging, the fracture networks need to be extracted (segmented) from the background. Unfortunately, available segmentation approaches in the literature do not provide satisfactory results on such narrow fractures. We therefore developed the multiscale Hessian fracture filter, with which we are able to extract the fracture networks from the datasets in a better way. The largest advantages of this technique are that it is inherently 3D, runs on desktop computers with limited resources, and is implemented in public domain software (ImageJ / FIJI). The results from the multiscale Hessian fracture filtering approach serve as input for porosity determination. Also

  4. Implementation of virtual models from sheet metal forming simulation into physical 3D colour models using 3D printing

    NASA Astrophysics Data System (ADS)

    Junk, S.

    2016-08-01

    Today the methods of numerical simulation of sheet metal forming offer a great diversity of possibilities for optimization in product development and in process design. However, the results from simulation are only available as virtual models. Because there are any forming tools available during the early stages of product development, physical models that could serve to represent the virtual results are therefore lacking. Physical 3D-models can be created using 3D-printing and serve as an illustration and present a better understanding of the simulation results. In this way, the results from the simulation can be made more “comprehensible” within a development team. This paper presents the possibilities of 3D-colour printing with particular consideration of the requirements regarding the implementation of sheet metal forming simulation. Using concrete examples of sheet metal forming, the manufacturing of 3D colour models will be expounded upon on the basis of simulation results.

  5. 3-D Particle Simulation of Current Sheet Instabilities

    NASA Astrophysics Data System (ADS)

    Wang, Zhenyu; Lin, Yu; Wang, Xueyi; Tummel, Kurt; Chen, Liu

    2015-11-01

    The electrostatic (ES) and electromagnetic (EM) instabilities of a Harris current sheet are investigated using a 3-D linearized (δf) gyrokinetic (GK) electron and fully kinetic (FK) ion (GeFi) particle simulation code. The equilibrium magnetic field consists of an asymptotic anti-parallel Bx 0 and a guide field BG. The ES simulations show the excitation of lower-hybrid drift instability (LHDI) at the current sheet edge. The growth rate of the 3-D LHDI is scanned through the (kx ,ky) space. The most unstable modes are found to be at k∥ = 0 for smaller ky. As ky increases, the growth rate shows two peaks at k∥ ≠ 0 , consistent with analytical GK theory. The eigenmode structure and growth rate of LHDI obtained from the GeFi simulation agree well with those obtained from the FK PIC simulation. Decreasing BG, the asymptotic βe 0, or background density can destabilize the LHDI. In the EM simulation, tearing mode instability is dominant in the cases with ky kx , there exist two unstable modes: a kink-like (LHDI) mode at the current sheet edge and a sausage-like mode at the sheet center. The results are compared with the GK eigenmode theory and the FK simulation.

  6. Simulation of human ischemic stroke in realistic 3D geometry

    NASA Astrophysics Data System (ADS)

    Dumont, Thierry; Duarte, Max; Descombes, Stéphane; Dronne, Marie-Aimée; Massot, Marc; Louvet, Violaine

    2013-06-01

    In silico research in medicine is thought to reduce the need for expensive clinical trials under the condition of reliable mathematical models and accurate and efficient numerical methods. In the present work, we tackle the numerical simulation of reaction-diffusion equations modeling human ischemic stroke. This problem induces peculiar difficulties like potentially large stiffness which stems from the broad spectrum of temporal scales in the nonlinear chemical source term as well as from the presence of steep spatial gradients in the reaction fronts, spatially very localized. Furthermore, simulations on realistic 3D geometries are mandatory in order to describe correctly this type of phenomenon. The main goal of this article is to obtain, for the first time, 3D simulations on realistic geometries and to show that the simulation results are consistent with those obtain in experimental studies or observed on MRI images in stroke patients. For this purpose, we introduce a new resolution strategy based mainly on time operator splitting that takes into account complex geometry coupled with a well-conceived parallelization strategy for shared memory architectures. We consider then a high order implicit time integration for the reaction and an explicit one for the diffusion term in order to build a time operator splitting scheme that exploits efficiently the special features of each problem. Thus, we aim at solving complete and realistic models including all time and space scales with conventional computing resources, that is on a reasonably powerful workstation. Consequently and as expected, 2D and also fully 3D numerical simulations of ischemic strokes for a realistic brain geometry, are conducted for the first time and shown to reproduce the dynamics observed on MRI images in stroke patients. Beyond this major step, in order to improve accuracy and computational efficiency of the simulations, we indicate how the present numerical strategy can be coupled with spatial

  7. 3-D Modeling of Pore Pressure Diffusion Beneath Koyna and Warna Reservoirs, Western India

    NASA Astrophysics Data System (ADS)

    Yadav, Amrita; Gahalaut, Kalpna; Purnachandra Rao, N.

    2017-03-01

    The mechanism of reservoir-triggered seismicity is well-understood and explains the earthquake occurrence at different reservoir sites. It can be attributed to the stresses due to water loading and to changes in fluid pressure in pores within the rock matrix. In the present study a 3-D fluid flow numerical model is used to investigate the pore pressure diffusion as a cause for continued seismicity in the Koyna-Warna region in western India. It is shown that reservoir water level fluctuations are sufficient to trigger earthquakes at the seismogenic depths in the region. Our numerical model suggests that a vertical fault with hydraulic conductivity in the range 2-6 m/day facilitates the diffusion of pressure at focal depths of earthquakes in the Koyna-Warna region. Also, for triggering of earthquakes a higher vertical conductivity is required for the Warna region than for the Koyna region. A lag of two months period is found between the maximum water level and the significant hydraulic head required to trigger earthquakes at the focal depth using the appropriate hydraulic conductivity for both the reservoirs.

  8. Stochastic Representation and Uncertainty Assessment of a Deep Geothermal Reservoir Using Cross-Borehole ERT: A 3D Synthetic Case

    NASA Astrophysics Data System (ADS)

    Brunet, P.; Gloaguen, E.

    2014-12-01

    Designing and monitoring of geothermal systems is a complex task which requires a multidisciplinary approach. Deep geothermal reservoir models are prone to greater uncertainty, with a lack of direct data and lower resolution of surface geophysical methods. However, recent technical advances have enabled the potential use of permanent downhole vertical resistivity arrays for monitoring fluid injection. As electrical resistivity is sensitive to temperature changes, such data could provide valuable information for deep geothermal reservoir characterization. The objective of this study is to assess the potential of time-lapse cross-borehole ERT to constrain 3D realizations of geothermal reservoir properties. The synthetic case of a permeable geothermal reservoir in a sedimentary basin was set up, as a confined deep and saline sandstone aquifer with intermediate reservoir temperatures (150ºC), depth (1 km) and 30m thickness. The reservoir permeability distribution is heterogeneous, as the result of a fluvial depositional environment. The ERT monitoring system design is a triangular arrangement of 3 wells at 150 m spacing, including 1 injection and 1 extraction well. The optimal number and spacing of electrodes of the ERT array design is site-specific and has been assessed through a sensibility study. Dipole-dipole and pole-pole electrode configurations were used. The study workflow was the following: 1) Generation of a reference reservoir model and 100 stochastic realizations of permeability; 2) Simulation of saturated single-phase flow and heat transport of reinjection of cooled formation fluid (50ºC) with TOUGH2 software; 3) Time-lapse forward ERT modeling on the reference model and all realizations (observed and simulated apparent resistivity change); 4) heuristic optimization on ERT computed and calculated data. Preliminary results show significant reduction of parameter uncertainty, hence realization space, with assimilation of cross-borehole ERT data. Loss in

  9. 3D Numerical Simulations of the Breakout Model

    NASA Astrophysics Data System (ADS)

    Choe, G. S.; Cheng, C. Z.; Lee, J.; Lynch, B. J.; Antiochos, S. K.; DeVore, C. R.; Zurbuchen, T. H.

    2005-05-01

    We present the continuing progress of the numerical simulations of the breakout model for coronal mass ejection initiation. To validate the 3D spherical ARMS code we have run the 2.5D breakout problem and compare the eruption to the published 2D results. The ARMS 2.5D CME also forms a large magnetic island ahead of the erupting plasmoid due to the code's excellent maintenance of equatorial symmetry. Progress on the fully 3D breakout problem is also discussed. To build up enough magnetic free energy for an eruption the active region field must be strong with a steep gradient near the polarity inversion line and the shear must be highly concentrated there. This requires adaptive griding techniques. In the current simulation, the active region to background field ratio is 20-to-1 and the neutral line is long compared to the active region width. We present the evolution of this topology under Br-conserving shearing flow and discuss implications for a 3D eruption. This work is supported by NASA and ONR. BJL is supported by NASA GSRP grant NGT5-50453.

  10. 3D EFT imaging with planar electrode array: Numerical simulation

    NASA Astrophysics Data System (ADS)

    Tuykin, T.; Korjenevsky, A.

    2010-04-01

    Electric field tomography (EFT) is the new modality of the quasistatic electromagnetic sounding of conductive media recently investigated theoretically and realized experimentally. The demonstrated results pertain to 2D imaging with circular or linear arrays of electrodes (and the linear array provides quite poor quality of imaging). In many applications 3D imaging is essential or can increase value of the investigation significantly. In this report we present the first results of numerical simulation of the EFT imaging system with planar array of electrodes which allows 3D visualization of the subsurface conductivity distribution. The geometry of the system is similar to the geometry of our EIT breast imaging system providing 3D conductivity imaging in form of cross-sections set with different depth from the surface. The EFT principle of operation and reconstruction approach differs from the EIT system significantly. So the results of numerical simulation are important to estimate if comparable quality of imaging is possible with the new contactless method. The EFT forward problem is solved using finite difference time domain (FDTD) method for the 8×8 square electrodes array. The calculated results of measurements are used then to reconstruct conductivity distributions by the filtered backprojections along electric field lines. The reconstructed images of the simple test objects are presented.

  11. Computational issues connected with 3D N-body simulations

    NASA Astrophysics Data System (ADS)

    Pfenniger, D.; Friedli, D.

    1993-03-01

    Computational problems related to modeling gravitational systems, and running and analyzing 3D N-body models are discussed. N-body simulations using Particle-Mesh techniques with polar grids are especially well-suited, and physically justified, when studying quiet evolutionary processes in disk galaxies. This technique allows large N, high central resolution, and is still the fastest one. Regardless of the method chosen to compute gravitation, softening is a compromise between HF amplification and resolution. Softened spherical and ellipsoidal kernels with variable resolution are set up. Detailed characteristics of the 3D polar grid, tests, code performances, and vectorization rates are also given. For integrating motion in rotating coordinates, a stable symplectic extension of the leap-frog algorithm is described. The technique used to search for periodic orbits in arbitrary N-body potentials and to determine their stability is explained.

  12. 3-D General Relativistic MHD Simulations of Generating Jets

    NASA Astrophysics Data System (ADS)

    Nishikawa, K.-I.; Koide, S.; Shibata, K.; Kudoh, T.; Sol, H.; Hughes, J. P.

    2001-12-01

    We have investigated the dynamics of an accretion disk around Schwarzschild black holes initially threaded by a uniform poloidal magnetic field in a non-rotating corona (either in a steady-state infalling state) around a non-rotating black hole using a 3-D GRMHD with the ``axisymmetry'' along the z-direction. Magnetic field is tightly twisted by the rotation of the disk, and plasmas in the shocked region of the disk are accelerated by J x B force to form bipolar relativistic jets. In order to investigate variabilities of generated relativistic jets and magnetic field structure inside jets, we have performed calculations using the 3-D GRMHD code with a full 3-dimensional system without the axisymmetry. We have investigated how the third dimension affects the global disk dynamics and jet generation. We will perform simulations with various incoming flows from an accompanying star.

  13. Jet Formation with 3-D General Relativistic MHD Simulations

    NASA Astrophysics Data System (ADS)

    Richardson, G. A.; Nishikawa, K.-I.; Preece, R.; Hardee, P.; Koide, S.; Shibata, K.; Kudoh, T.; Sol, H.; Hughes, J. P.; Fishman, J.

    2002-12-01

    We have investigated the dynamics of an accretion disk around Schwarzschild black holes initially threaded by a uniform poloidal magnetic field in a non-rotating corona (in a steady-state infalling state) around a non-rotating black hole using 3-D GRMHD with the ``axisymmetry'' along the z-direction. The magnetic field is tightly twisted by the rotation of the accretion disk, and plasmas in the shocked region of the disk are accelerated by the J x B force to form bipolar relativistic jets. In order to investigate variabilities of generated relativistic jets and the magnetic field structure inside jets, we have performed calculations using the 3-D GRMHD code with a full 3-dimensional system without the axisymmetry. We have investigated how the third dimension affects the global disk dynamics and jet generation. We will perform simulations with various incoming flows from an accompanying star.

  14. 3-D General Relativistic MHD Simulations of Generating Jets

    NASA Astrophysics Data System (ADS)

    Nishikawa, Ken-Ichi; Koide, Shinji; Shibata, Kazunari; Kudoh, Takashiro; Sol, Helene; Hughes, John

    2002-04-01

    We have investigated the dynamics of an accretion disk around Schwarzschild black holes initially threaded by a uniform poloidal magnetic field in a non-rotating corona (either in a steady-state infalling state) around a non-rotating black hole using a 3-D GRMHD with the ``axisymmetry'' along the z-direction. Magnetic field is tightly twisted by the rotation of the disk, and plasmas in the shocked region of the disk are accelerated by J × B force to form bipolar relativistic jets. In order to investigate variabilities of generated relativistic jets and magnetic field structure inside jets, we have performed calculations using the 3-D GRMHD code with a full 3-dimensional system without the axisymmetry. We have investigated how the third dimension affects the global disk dynamics and jet generation. We will perform simulations with various incoming flows from an accompanying star.

  15. Virtual environment display for a 3D audio room simulation

    NASA Technical Reports Server (NTRS)

    Chapin, William L.; Foster, Scott H.

    1992-01-01

    The development of a virtual environment simulation system integrating a 3D acoustic audio model with an immersive 3D visual scene is discussed. The system complements the acoustic model and is specified to: allow the listener to freely move about the space, a room of manipulable size, shape, and audio character, while interactively relocating the sound sources; reinforce the listener's feeling of telepresence in the acoustical environment with visual and proprioceptive sensations; enhance the audio with the graphic and interactive components, rather than overwhelm or reduce it; and serve as a research testbed and technology transfer demonstration. The hardware/software design of two demonstration systems, one installed and one portable, are discussed through the development of four iterative configurations.

  16. 3D-CANVENT: An interactive mine ventilation simulator

    SciTech Connect

    Hardcastle, S.G.

    1995-12-31

    3D-CANVENT is a software package that integrates advanced computer aided design (ACAD) true 3D graphics with a mine ventilation simulator. The package runs as a Windows{trademark} application to access its printer drivers environment and does not need third party CAD software. It is composed of two primary modules: DMVENT and MINEDESIGNER. DMVENT is a traditional Fortran coded Hardy-Cross iterative ventilation network solver written in 1980 with thermodynamic capabilities. This module is relatively unchanged with the traditional data input options for branch type, specified or calculated resistances, fixed flows, and fixed or variable pressure fans. MINEDESIGNER is the graphics engine that optimizes the ventilation design process. It performs the front-end transformation of input data entered in the graphical interface into the correct format for the solver. At the back-end it reconverts the historically standard tabular data output from the solver into an easily viewed graphical format. ACAD features of MINEDESIGNER are used to generate a 3D wire-frame node and branch network of the mine`s ventilation system. The network can be displayed in up to 4 views orientated to XYZ planes or a 3D view. AU the views have zoom, pan, slice and rotate options. The graphical interface efficiently permits data entry and editing via a mouse with pick-and-point item selection. Branches can be found or added with {open_quotes}search{close_quotes} and {open_quotes}join{close_quotes} options. Visual interpretation is enhanced by the 16 colour options for branches and numerous graphical attributes. Network locations are readily identified by alpha-numeric names for branches, junctions and fans, and also the logical numbering of junctions. The program is also readily expandable for pollutant simulation and control/monitoring applications.

  17. Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Deliverable 2.5.4, Ferron Sandstone lithologic strip logs, Emergy & Sevier Counties, Utah: Volume I

    SciTech Connect

    Allison, M.L.

    1995-12-08

    Strip logs for 491 wells were produced from a digital subsurface database of lithologic descriptions of the Ferron Sandstone Member of the Mancos Shale. This subsurface database covers wells from the parts of Emery and Sevier Counties in central Utah that occur between Ferron Creek on the north and Last Chance Creek on the south. The lithologic descriptions were imported into a logging software application designed for the display of stratigraphic data. Strip logs were produced at a scale of one inch equals 20 feet. The strip logs were created as part of a study by the Utah Geological Survey to develop a comprehensive, interdisciplinary, and qualitative characterization of a fluvial-deltaic reservoir using the Ferron Sandstone as a surface analogue. The study was funded by the U.S. Department of Energy (DOE) under the Geoscience/Engineering Reservoir Characterization Program.

  18. Using Delft3D to Simulate Current Energy Conversion

    NASA Astrophysics Data System (ADS)

    James, S. C.; Chartrand, C.; Roberts, J.

    2015-12-01

    As public concern with renewable energy increases, current energy conversion (CEC) technology is being developed to optimize energy output and minimize environmental impact. CEC turbines generate energy from tidal and current systems and create wakes that interact with turbines located downstream of a device. The placement of devices can greatly influence power generation and structural reliability. CECs can also alter the ecosystem process surrounding the turbines, such as flow regimes, sediment dynamics, and water quality. Software is needed to investigate specific CEC sites to simulate power generation and hydrodynamic responses of a flow through a CEC turbine array. This work validates Delft3D against several flume experiments by simulating the power generation and hydrodynamic response of flow through a turbine or actuator disc(s). Model parameters are then calibrated against these data sets to reproduce momentum removal and wake recovery data with 3-D flow simulations. Simulated wake profiles and turbulence intensities compare favorably to the experimental data and demonstrate the utility and accuracy of a fast-running tool for future siting and analysis of CEC arrays in complex domains.

  19. 3-D Imaging and Simulation for Nephron Sparing Surgical Training.

    PubMed

    Ahmadi, Hamed; Liu, Jen-Jane

    2016-08-01

    Minimally invasive partial nephrectomy (MIPN) is now considered the procedure of choice for small renal masses largely based on functional advantages over traditional open surgery. Lack of haptic feedback, the need for spatial understanding of tumor borders, and advanced operative techniques to minimize ischemia time or achieve zero-ischemia PN are among factors that make MIPN a technically demanding operation with a steep learning curve for inexperienced surgeons. Surgical simulation has emerged as a useful training adjunct in residency programs to facilitate the acquisition of these complex operative skills in the setting of restricted work hours and limited operating room time and autonomy. However, the majority of available surgical simulators focus on basic surgical skills, and procedure-specific simulation is needed for optimal surgical training. Advances in 3-dimensional (3-D) imaging have also enhanced the surgeon's ability to localize tumors intraoperatively. This article focuses on recent procedure-specific simulation models for laparoscopic and robotic-assisted PN and advanced 3-D imaging techniques as part of pre- and some cases, intraoperative surgical planning.

  20. Joint Stochastic Inversion of Pre-Stack 3D Seismic Data and Well Logs for High Resolution Hydrocarbon Reservoir Characterization

    NASA Astrophysics Data System (ADS)

    Torres-Verdin, C.

    2007-05-01

    This paper describes the successful implementation of a new 3D AVA stochastic inversion algorithm to quantitatively integrate pre-stack seismic amplitude data and well logs. The stochastic inversion algorithm is used to characterize flow units of a deepwater reservoir located in the central Gulf of Mexico. Conventional fluid/lithology sensitivity analysis indicates that the shale/sand interface represented by the top of the hydrocarbon-bearing turbidite deposits generates typical Class III AVA responses. On the other hand, layer- dependent Biot-Gassmann analysis shows significant sensitivity of the P-wave velocity and density to fluid substitution. Accordingly, AVA stochastic inversion, which combines the advantages of AVA analysis with those of geostatistical inversion, provided quantitative information about the lateral continuity of the turbidite reservoirs based on the interpretation of inverted acoustic properties (P-velocity, S-velocity, density), and lithotype (sand- shale) distributions. The quantitative use of rock/fluid information through AVA seismic amplitude data, coupled with the implementation of co-simulation via lithotype-dependent multidimensional joint probability distributions of acoustic/petrophysical properties, yields accurate 3D models of petrophysical properties such as porosity and permeability. Finally, by fully integrating pre-stack seismic amplitude data and well logs, the vertical resolution of inverted products is higher than that of deterministic inversions methods.

  1. Development of a 3D particle treecode for plasma simulations

    NASA Astrophysics Data System (ADS)

    Ong, Benjamin; Christlieb, Andrew; Krasny, Robert

    2008-11-01

    In this work we present a fully 3-D Boundary Integral Treecode (BIT). We apply the method to several classic problems such as sheath formation and 3D simulations of a Penning trap. In addition, we investigate the ability of the solver to naturally capture Coloumb scattering. A key point in the investigation is to understand the effect of different types of regularizations, and how to appropriately incorporate the regularization in the BIT framework. This work builds on substantial efforts in 1- and 2-D. [1] R. Krasny and K. Lindsay, A particle method and adaptive treecode for vortex sheet motion in 3-D flow, JCP, Vol. 172, No. 2, 879-907 [2] K. Matyash, R. Schneider, R. Sydora, and F. Taccogna, Application of a Grid-Free Kinetic Model to the Collisionless Sheath, Contrib. Plasma Phys, Vol. 48, No. 1-3, 116-120 (2008) [3] K. Cartwright and A. Christlieb, Boundary Integral Corrected Particle in Cell, SIAM Journal on Sci. Comput., submitted [4] A. Christlieb, R. Krasny, B. Ong and J. Qiu, A Step Towards Addressing Temporal Multi-scale Problems in Plasma Physics, in prep.

  2. Fracture-network 3D characterization in a deformed chalk reservoir analogue -- the Laegerdorf case

    SciTech Connect

    Koestler, A.G.; Reksten, K.

    1995-09-01

    Quantitative descriptions of 3D fracture networks in terms of fracture characteristics and connectivity are necessary for reservoir evaluation, management, and EOR programs of fractured reservoirs. The author`s research has focused on an analogue to North Sea fractured chalk reservoirs that is excellently exposed near Laegerdorf, northwest Germany. An underlying salt diapir uplifted and deformed Upper Cretaceous chalk; the cement industry now exploits it. The fracture network in the production wall of the quarry was characterized and mapped at different scales, and 12 profiles of the 230-m wide and 35-m high production wall were investigated as the wall receded 25 m. In addition, three wells were drilled into the chalk volume. The wells were cored and the wellbores were imaged with both the resistivity formation micro scanner (FMS) and the sonic circumferential borehole image logger (CBIL). The large amount of fracture data was analyzed with respect to parameters, such as fracture density distribution, orientation, and length distribution, and in terms of the representativity and predictability of data sets collected from restricted rock volumes.

  3. Advanced system for 3D dental anatomy reconstruction and 3D tooth movement simulation during orthodontic treatment

    NASA Astrophysics Data System (ADS)

    Monserrat, Carlos; Alcaniz-Raya, Mariano L.; Juan, M. Carmen; Grau Colomer, Vincente; Albalat, Salvador E.

    1997-05-01

    This paper describes a new method for 3D orthodontics treatment simulation developed for an orthodontics planning system (MAGALLANES). We develop an original system for 3D capturing and reconstruction of dental anatomy that avoid use of dental casts in orthodontic treatments. Two original techniques are presented, one direct in which data are acquired directly form patient's mouth by mean of low cost 3D digitizers, and one mixed in which data are obtained by 3D digitizing of hydrocollids molds. FOr this purpose we have designed and manufactured an optimized optical measuring system based on laser structured light. We apply these 3D dental models to simulate 3D movement of teeth, including rotations, during orthodontic treatment. The proposed algorithms enable to quantify the effect of orthodontic appliance on tooth movement. The developed techniques has been integrated in a system named MAGALLANES. This original system present several tools for 3D simulation and planning of orthodontic treatments. The prototype system has been tested in several orthodontic clinic with very good results.

  4. Interfacing 3D micro/nanochannels with a branch-shaped reservoir enhances fluid and mass transport

    NASA Astrophysics Data System (ADS)

    Kumar, Prasoon; Gandhi, Prasanna S.; Majumder, Mainak

    2017-01-01

    Three-dimensional (3D) micro/nanofluidic devices can accelerate progress in numerous fields such as tissue engineering, drug delivery, self-healing and cooling devices. However, efficient connections between networks of micro/nanochannels and external fluidic ports are key to successful applications of 3D micro/nanofluidic devices. Therefore, in this work, the extent of the role of reservoir geometry in interfacing with vascular (micro/nanochannel) networks, and in the enabling of connections with external fluidic ports while maintaining the compactness of devices, has been experimentally and theoretically investigated. A statistical modelling suggested that a branch-shaped reservoir demonstrates enhanced interfacing with vascular networks when compared to other regular geometries of reservoirs. Time-lapse dye flow experiments by capillary action through fabricated 3D micro/nanofluidic devices confirmed the connectivity of branch-shaped reservoirs with micro/nanochannel networks in fluidic devices. This demonstrated a ~2.2-fold enhancement of the volumetric flow rate in micro/nanofluidic networks when interfaced to branch-shaped reservoirs over rectangular reservoirs. The enhancement is due to a ~2.8-fold increase in the perimeter of the reservoirs. In addition, the mass transfer experiments exhibited a ~1.7-fold enhancement in solute flux across 3D micro/nanofluidic devices that interfaced with branch-shaped reservoirs when compared to rectangular reservoirs. The fabrication of 3D micro/nanofluidic devices and their efficient interfacing through branch-shaped reservoirs to an external fluidic port can potentially enable their use in complex applications, in which enhanced surface-to-volume interactions are desirable.

  5. Composite manufacturing: Simulation of 3-D resin transfer molding

    NASA Astrophysics Data System (ADS)

    Tan, Cheng Ping

    1998-10-01

    A technique was developed for simulating the resin transfer molding (RTM) process. The major feature of the technique is a computational steering system that enables the user to make changes during the simulation. Specifically, at any instance, the user can inspect the progress of the resin front. On the basis of the observed resin front position, the user can, as needed, change the port and vent locations, open and close ports and vents, adjust the inlet and exit pressures or flow rates, and reorient the mold with respect to the gravitational field. Additionally, the user can "rewind" the simulator to any previous time in the mold filling process, make any of the above changes and then continue the simulation. The technique is augmented by a computer code which has three main components, the Simulator, the Graphics User Interface (GUI), and the Global Data Storage. The Simulator is a finite element code that calculates the resin flow inside the fiber preform. The GUI serves as the interface between the user and the Simulator; it provides the commands to the Simulator and displays the results. The Global Data Storage is the module that manages the exchange of data between the GUI and the Simulator. The computer code (designated as SUPERTMsb-3D) is suitable for simulating the resin flow inside two-dimensional as well as three-dimensional fiber preforms of arbitrary shapes. The use of this computer code is illustrated through sample problems. These problems demonstrate how (with this code) the designer can establish the port and vent locations, opening and closing sequences of ports and vents such that the fiber preform is filled completely in the shortest time with the fewest number of vents.

  6. 3D FEM Simulation of Flank Wear in Turning

    NASA Astrophysics Data System (ADS)

    Attanasio, Aldo; Ceretti, Elisabetta; Giardini, Claudio

    2011-05-01

    This work deals with tool wear simulation. Studying the influence of tool wear on tool life, tool substitution policy and influence on final part quality, surface integrity, cutting forces and power consumption it is important to reduce the global process costs. Adhesion, abrasion, erosion, diffusion, corrosion and fracture are some of the phenomena responsible of the tool wear depending on the selected cutting parameters: cutting velocity, feed rate, depth of cut, …. In some cases these wear mechanisms are described by analytical models as a function of process variables (temperature, pressure and sliding velocity along the cutting surface). These analytical models are suitable to be implemented in FEM codes and they can be utilized to simulate the tool wear. In the present paper a commercial 3D FEM software has been customized to simulate the tool wear during turning operations when cutting AISI 1045 carbon steel with uncoated tungsten carbide tip. The FEM software was improved by means of a suitable subroutine able to modify the tool geometry on the basis of the estimated tool wear as the simulation goes on. Since for the considered couple of tool-workpiece material the main phenomena generating wear are the abrasive and the diffusive ones, the tool wear model implemented into the subroutine was obtained as combination between the Usui's and the Takeyama and Murata's models. A comparison between experimental and simulated flank tool wear curves is reported demonstrating that it is possible to simulate the tool wear development.

  7. Simulation of 3D Global Wave Propagation Through Geodynamic Models

    NASA Astrophysics Data System (ADS)

    Schuberth, B.; Piazzoni, A.; Bunge, H.; Igel, H.; Steinle-Neumann, G.

    2005-12-01

    This project aims at a better understanding of the forward problem of global 3D wave propagation. We use the spectral element program "SPECFEM3D" (Komatitsch and Tromp, 2002a,b) with varying input models of seismic velocities derived from mantle convection simulations (Bunge et al., 2002). The purpose of this approach is to obtain seismic velocity models independently from seismological studies. In this way one can test the effects of varying parameters of the mantle convection models on the seismic wave field. In order to obtain the seismic velocities from the temperature field of the geodynamical simulations we follow a mineral physics approach. Assuming a certain mantle composition (e.g. pyrolite with CMASF composition) we compute the stable phases for each depth (i.e. pressure) and temperature by system Gibbs free energy minimization. Elastic moduli and density are calculated from the equations of state of the stable mineral phases. For this we use a mineral physics database derived from calorimetric experiments (enthalphy and entropy of formation, heat capacity) and EOS parameters.

  8. Dust emission in simulated dwarf galaxies using GRASIL-3D

    NASA Astrophysics Data System (ADS)

    Santos-Santos, I. M.; Domínguez-Tenreiro, R.; Granato, G. L.; Brook, C. B.; Obreja, A.

    2017-03-01

    Recent Herschel observations of dwarf galaxies have shown a wide diversity in the shapes of their IR-submm spectral energy distributions as compared to more massive galaxies, presenting features that cannot be explained with the current models. In order to understand the physics driving these differences, we have computed the emission of a sample of simulated dwarf galaxies using the radiative transfer code GRASIL-3D. This code separately treats the radiative transfer in dust grains from molecular clouds and cirri. The simulated galaxies have masses ranging from 10^6-10^9 M_⊙ and have evolved within a Local Group environment by using CLUES initial conditions. We show that their IR band luminosities are in agreement with observations, with their SEDs reproducing naturally the particular spectral features observed. We conclude that the GRASIL-3D two-component model gives a physical interpretation to the emission of dwarf galaxies, with molecular clouds (cirri) as the warm (cold) dust components needed to recover observational data.

  9. GBS: Global 3D simulation of tokamak edge region

    NASA Astrophysics Data System (ADS)

    Zhu, Ben; Fisher, Dustin; Rogers, Barrett; Ricci, Paolo

    2012-10-01

    A 3D two-fluid global code, namely Global Braginskii Solver (GBS), is being developed to explore the physics of turbulent transport, confinement, self-consistent profile formation, pedestal scaling and related phenomena in the edge region of tokamaks. Aimed at solving drift-reduced Braginskii equations [1] in complex magnetic geometry, the GBS is used for turbulence simulation in SOL region. In the recent upgrade, the simulation domain is expanded into close flux region with twist-shift boundary conditions. Hence, the new GBS code is able to explore global transport physics in an annular full-torus domain from the top of the pedestal into the far SOL. We are in the process of identifying and analyzing the linear and nonlinear instabilities in the system using the new GBS code. Preliminary results will be presented and compared with other codes if possible.[4pt] [1] A. Zeiler, J. F. Drake and B. Rogers, Phys. Plasmas 4, 2134 (1997)

  10. Coniferous Canopy BRF Simulation Based on 3-D Realistic Scene

    NASA Technical Reports Server (NTRS)

    Wang, Xin-yun; Guo, Zhi-feng; Qin, Wen-han; Sun, Guo-qing

    2011-01-01

    It is difficulties for the computer simulation method to study radiation regime at large-scale. Simplified coniferous model was investigate d in the present study. It makes the computer simulation methods such as L-systems and radiosity-graphics combined method (RGM) more powerf ul in remote sensing of heterogeneous coniferous forests over a large -scale region. L-systems is applied to render 3-D coniferous forest scenarios: and RGM model was used to calculate BRF (bidirectional refle ctance factor) in visible and near-infrared regions. Results in this study show that in most cases both agreed well. Meanwhiie at a tree and forest level. the results are also good.

  11. 3-D MHD Simulation of Oscillating Field Current Drive

    NASA Astrophysics Data System (ADS)

    Ebrahimi, F.; Prager, S. C.; Wright, J. C.

    2000-10-01

    Oscillating Field Current Drive (OFCD) is a proposed low frequency steady-state current drive technique for the Reversed Field Pinch (RFP). In OFCD toroidal and poloidal oscillating electric fields are applied with 90^circ phase difference to inject magnetic helicity. In the present work, the 3-D nonlinear, resistive MHD code DEBS is used to simulate OFCD in relaxed RFP plasmas. The present simulations are at high Lundquist number S=10^5 and low spect ratio R/a=1.5. The physics issues investigated are the response of background magnetic fluctuations to the oscillating fields, the relative contributions of the tearing mode dynamo and the oscillating fields to the current profile, and the sustainment and control of the steady-state current profile. Initial results with low amplitude oscillating fields show the expected increase in magnetic helicity and current. Results with higher amplitude will also be presented.

  12. Physics and 3D in Flash Simulations: Open Source Reality

    NASA Astrophysics Data System (ADS)

    Harold, J. B.; Dusenbery, P.

    2009-12-01

    Over the last decade our ability to deliver simulations over the web has steadily advanced. The improvements in speed of the Adobe Flash engine, and the development of open source tools to expand it, allow us to deliver increasingly sophisticated simulation based games through the browser, with no additional downloads required. In this paper we will present activities we are developing as part of two asteroids education projects: Finding NEO (funded through NSF and NASA SMD), and Asteroids! (funded through NSF). The first activity is Rubble!, an asteroids deflection game built on the open source Box2D physics engine. This game challenges players to push asteroids in to safe orbits before they crash in to the Earth. The Box2D engine allows us to go well beyond simple 2-body orbital calculations and incorporate “rubble piles”. These objects, which are representative of many asteroids, are composed of 50 or more individual rocks which gravitationally bind and separate in realistic ways. Even bombs can be modeled with sufficient physical accuracy to convince players of the hazards of trying to “blow up” incoming asteroids. The ability to easily build games based on underlying physical models allows us to address physical misconceptions in a natural way: by having the player operate in a world that directly collides with those misconceptions. Rubble! provides a particularly compelling example of this due to the variety of well documented misconceptions regarding gravity. The second activity is a Light Curve challenge, which uses the open source PaperVision3D tools to analyze 3D asteroid models. The goal of this activity is to introduce the player to the concept of “light curves”, measurements of asteroid brightness over time which are used to calculate the asteroid’s period. These measurements can even be inverted to generate three dimensional models of asteroids that are otherwise too small and distant to directly image. Through the use of the Paper

  13. Optimizing prostate needle biopsy through 3D simulation

    NASA Astrophysics Data System (ADS)

    Zeng, Jianchao; Kaplan, Charles; Xuan, Jian Hua; Sesterhenn, Isabell A.; Lynch, John H.; Freedman, Matthew T.; Mun, Seong K.

    1998-06-01

    Prostate needle biopsy is used for the detection of prostate cancer. The protocol of needle biopsy that is currently routinely used in the clinical environment is the systematic sextant technique, which defines six symmetric locations on the prostate surface for needle insertion. However, this protocol has been developed based on the long-term observation and experience of urologists. Little quantitative or scientific evidence supports the use of this biopsy technique. In this research, we aim at developing a statistically optimized new prostate needle biopsy protocol to improve the quality of diagnosis of prostate cancer. This new protocol will be developed by using a three-dimensional (3-D) computer- based probability map of prostate cancer. For this purpose, we have developed a computer-based 3-D visualization and simulation system with prostate models constructed from the digitized prostate specimens, in which the process of prostate needle biopsy can be simulated automatically by the computer. In this paper, we first develop an interactive biopsy simulation mode in the system, and evaluate the performance of the automatic biopsy simulation with the sextant biopsy protocol by comparing the results by the urologist using the interactive simulation mode with respect to 53 prostate models. This is required to confirm that the automatic simulation is accurate and reliable enough for the simulation with respect to a large number of prostate models. Then we compare the performance of the existing protocols using the automatic biopsy simulation system with respect to 107 prostate models, which will statistically identify if one protocol is better than another. Since the estimation of tumor volume is extremely important in determining the significance of a tumor and in deciding appropriate treatment methods, we further investigate correlation between the tumor volume and the positive core volume with 89 prostate models. This is done in order to develop a method to

  14. 3-D reservoir characterization of the House Creek oil field, Powder River Basin, Wyoming

    USGS Publications Warehouse

    Higley, Debra K.; Pantea, Michael P.; Slatt, Roger M.

    1997-01-01

    This CD-ROM is intended to serve a broad audience. An important purpose is to explain geologic and geochemical factors that control petroleum production from the House Creek Field. This information may serve as an analog for other marine-ridge sandstone reservoirs. The 3-D slide and movie images are tied to explanations and 2-D geologic and geochemical images to visualize geologic structures in three dimensions, explain the geologic significance of porosity/permeability distribution across the sandstone bodies, and tie this to petroleum production characteristics in the oil field. Movies, text, images including scanning electron photomicrographs (SEM), thin-section photomicrographs, and data files can be copied from the CD-ROM for use in external mapping, statistical, and other applications.

  15. Ground Motion and Variability from 3-D Deterministic Broadband Simulations

    NASA Astrophysics Data System (ADS)

    Withers, Kyle Brett

    The accuracy of earthquake source descriptions is a major limitation in high-frequency (> 1 Hz) deterministic ground motion prediction, which is critical for performance-based design by building engineers. With the recent addition of realistic fault topography in 3D simulations of earthquake source models, ground motion can be deterministically calculated more realistically up to higher frequencies. We first introduce a technique to model frequency-dependent attenuation and compare its impact on strong ground motions recorded for the 2008 Chino Hills earthquake. Then, we model dynamic rupture propagation for both a generic strike-slip event and blind thrust scenario earthquakes matching the fault geometry of the 1994 Mw 6.7 Northridge earthquake along rough faults up to 8 Hz. We incorporate frequency-dependent attenuation via a power law above a reference frequency in the form Q0fn, with high accuracy down to Q values of 15, and include nonlinear effects via Drucker-Prager plasticity. We model the region surrounding the fault with and without small-scale medium complexity in both a 1D layered model characteristic of southern California rock and a 3D medium extracted from the SCEC CVMSi.426 including a near-surface geotechnical layer. We find that the spectral acceleration from our models are within 1-2 interevent standard deviations from recent ground motion prediction equations (GMPEs) and compare well with that of recordings from strong ground motion stations at both short and long periods. At periods shorter than 1 second, Q(f) is needed to match the decay of spectral acceleration seen in the GMPEs as a function of distance from the fault. We find that the similarity between the intraevent variability of our simulations and observations increases when small-scale heterogeneity and plasticity are included, extremely important as uncertainty in ground motion estimates dominates the overall uncertainty in seismic risk. In addition to GMPEs, we compare with simple

  16. Study, simulation and design of a 3D clinostat

    NASA Astrophysics Data System (ADS)

    Pavone, Valentina; Guarnieri, Vincenzo; Lobascio, Cesare; Soma, Aurelio; Bosso, Nicola; Lamantea, Matteo Maria

    High cost and limited number of physically executable experiments in space have introduced the need for ground simulation systems that enable preparing experiments to be carried out on board, identifying phenomena associated with the altered gravity conditions, and taking advantage of these conditions, as in Biotechnology. Among systems developed to simulate microgravity, especially for life sciences experiments, different types of clinostats were realized. This work deals with mechanical design of a three-dimensional clinostat and simulation of the dynamic behavior of the system by varying the operating parameters. The design and simulation phase was preceded by a careful analysis of the state of art and by the review of the most recent results, in particular from the major investigators of Life Sciences in Space. The mechanical design is quite innovative by adoption of a structure entirely in aluminum, which allows robustness while reducing the overall weight. The transmission system of motion has been optimized by means of brushless DC micro motors, light and compact, which helped to reduce weight, dimensions, power consumption and increase the reliability and durability of the system. The study of the dynamic behavior using SIMPACK, a multibody simulation software, led to results in line with those found in the most important and recent scientific publications. This model was also appropriately configured to represent any desired operating condition, and for eventual system scalability. It would be interesting to generate simulated hypogravity - e.g.: 0.38-g (Mars) or 0.17-g (Moon). This would allow to investigate how terrestrial life forms can grow in other planetary habitats, or to determine the gravity threshold response of different organisms. At the moment, such a system can only be achieved by centrifuges in real microgravity. We are confident that simulation and associated tests with our 3D clinostat can help adjusting the parameters allowing variable g

  17. 3D Simulation Modeling of the Tooth Wear Process.

    PubMed

    Dai, Ning; Hu, Jian; Liu, Hao

    2015-01-01

    Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation.

  18. Unsteady 3D flow simulations in cranial arterial tree

    NASA Astrophysics Data System (ADS)

    Grinberg, Leopold; Anor, Tomer; Madsen, Joseph; Karniadakis, George

    2008-11-01

    High resolution unsteady 3D flow simulations in major cranial arteries have been performed. Two cases were considered: 1) a healthy volunteer with a complete Circle of Willis (CoW); and 2) a patient with hydrocephalus and an incomplete CoW. Computation was performed on 3344 processors of the new half petaflop supercomputer in TACC. Two new numerical approaches were developed and implemented: 1) a new two-level domain decomposition method, which couples continuous and discontinuous Galerkin discretization of the computational domain; and 2) a new type of outflow boundary conditions, which imposes, in an accurate and computationally efficient manner, clinically measured flow rates. In the first simulation, a geometric model of 65 cranial arteries was reconstructed. Our simulation reveals a high degree of asymmetry in the flow at the left and right parts of the CoW and the presence of swirling flow in most of the CoW arteries. In the second simulation, one of the main findings was a high pressure drop at the right anterior communicating artery (PCA). Due to the incompleteness of the CoW and the pressure drop at the PCA, the right internal carotid artery supplies blood to most regions of the brain.

  19. 3D Simulation Modeling of the Tooth Wear Process

    PubMed Central

    Dai, Ning; Hu, Jian; Liu, Hao

    2015-01-01

    Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation. PMID:26241942

  20. MPSalsa 3D Simulations of Chemically Reacting Flows

    DOE Data Explorer

    Many important scientific and engineering applications require a detailed analysis of complex systems with coupled fluid flow, thermal energy transfer, mass transfer and nonequilibrium chemical reactions. Currently, computer simulations of these complex reacting flow problems are limited to idealized systems in one or two spatial dimensions when coupled with a detailed, fundamental chemistry model. The goal of our research is to develop, analyze and implement advanced MP numerical algorithms that will allow high resolution 3D simulations with an equal emphasis on fluid flow and chemical kinetics modeling. In our research, we focus on the development of new, fully coupled, implicit solution strategies that are based on robust MP iterative solution methods (copied from http://www.cs.sandia.gov/CRF/MPSalsa/). These simulations are needed for scientific and technical areas such as: combustion research for transportation, atmospheric chemistry modeling for pollution studies, chemically reacting flow models for analysis and control of manufacturing processes, surface catalytic reactors for methane to methanol conversion and chemical vapor deposition (CVD) process modeling for production of advanced semiconductor materials (http://www.cs.sandia.gov/CRF/MPSalsa/).

    This project website provides six QuickTime videos of these simulations, along with a small image gallery and slideshow animations. A list of related publications and conference presentations is also made available.

  1. Application of Cutting-Edge 3D Seismic Attribute Technology to the Assessment of Geological Reservoirs for CO2 Sequestration

    SciTech Connect

    Christopher Liner; Jianjun Zeng; Po Geng Heather King Jintan Li; Jennifer Califf; John Seales

    2010-03-31

    The goals of this project were to develop innovative 3D seismic attribute technologies and workflows to assess the structural integrity and heterogeneity of subsurface reservoirs with potential for CO{sub 2} sequestration. Our specific objectives were to apply advanced seismic attributes to aide in quantifying reservoir properies and lateral continuity of CO{sub 2} sequestration targets. Our study area is the Dickman field in Ness County, Kansas, a type locality for the geology that will be encountered for CO{sub 2} sequestration projects from northern Oklahoma across the U.S. midcontent to Indiana and beyond. Since its discovery in 1962, the Dickman Field has produced about 1.7 million barrels of oil from porous Mississippian carbonates with a small structural closure at about 4400 ft drilling depth. Project data includes 3.3 square miles of 3D seismic data, 142 wells, with log, some core, and oil/water production data available. Only two wells penetrate the deep saline aquifer. Geological and seismic data were integrated to create a geological property model and a flow simulation grid. We systematically tested over a dozen seismic attributes, finding that curvature, SPICE, and ANT were particularly useful for mapping discontinuities in the data that likely indicated fracture trends. Our simulation results in the deep saline aquifer indicate two effective ways of reducing free CO{sub 2}: (a) injecting CO{sub 2} with brine water, and (b) horizontal well injection. A tuned combination of these methods can reduce the amount of free CO{sub 2} in the aquifer from over 50% to less than 10%.

  2. Photon Scattering in 3D Radiative MHD Simulations

    NASA Astrophysics Data System (ADS)

    Hayek, Wolfgang

    2009-09-01

    Recent results from 3D time-dependent radiative hydrodynamic simulations of stellar atmospheres are presented, which include the effects of coherent scattering in the radiative transfer treatment. Rayleigh scattering and electron scattering are accounted for in the source function, requiring an iterative solution of the transfer equation. Opacities and scattering coefficients are treated in the multigroup opacity approximation. The impact of scattering on the horizontal mean temperature structure is investigated, which is an important diagnostic for model atmospheres, with implications for line formation and stellar abundance measurements. We find that continuum scattering is not important for the atmosphere of a metal-poor Sun with metailicity [Fe/H] = -3.0, similar to the previously investigated photosphere at solar metallicity.

  3. Colossal Tooling Design: 3D Simulation for Ergonomic Analysis

    NASA Technical Reports Server (NTRS)

    Hunter, Steve L.; Dischinger, Charles; Thomas, Robert E.; Babai, Majid

    2003-01-01

    The application of high-level 3D simulation software to the design phase of colossal mandrel tooling for composite aerospace fuel tanks was accomplished to discover and resolve safety and human engineering problems. The analyses were conducted to determine safety, ergonomic and human engineering aspects of the disassembly process of the fuel tank composite shell mandrel. Three-dimensional graphics high-level software, incorporating various ergonomic analysis algorithms, was utilized to determine if the process was within safety and health boundaries for the workers carrying out these tasks. In addition, the graphical software was extremely helpful in the identification of material handling equipment and devices for the mandrel tooling assembly/disassembly process.

  4. 3D simulations of an electrostatic quadrupole injector

    SciTech Connect

    Grote, D.P. |; Friedman, A.; Yu, S.

    1993-02-01

    Analysis of the dynamics of a space charge dominated beam in a lattice of electrostatic focusing structures requires a full three-dimensional conic that includes self-consistent space charge fields and the fields from the complex conductor shapes. The existing WARP3d code, a particle simulation code which has been developed for heavy-ion fusion (HIF) applications contains machinery for handling particles in three-dimensional fields. A successive overrelaxation field solver with subgrid-scale placement of boundaries for rounded surface and four-fold symmetry has been added to the code. The electrostatic quadrupole (ESQ) injector for the ILSE accelerator facility being planned at Lawrence Berkeley Laboratory is shown as an application. The issue of concern is possible emittance degradation because the focusing voltages are a significant fraction of the particles` energy and because there are significant nonlinear fields arising from the shapes of the quadrupole structures.

  5. 3D geomechanical-numerical modelling of the absolute stress state for geothermal reservoir exploration

    NASA Astrophysics Data System (ADS)

    Reiter, Karsten; Heidbach, Oliver; Moeck, Inga

    2013-04-01

    For the assessment and exploration of a potential geothermal reservoir, the contemporary in-situ stress is of key importance in terms of well stability and orientation of possible fluid pathways. However, available data, e.g. Heidbach et al. (2009) or Zang et al. (2012), deliver only point wise information of parts of the six independent components of the stress tensor. Moreover most measurements of the stress orientation and magnitude are done for hydrocarbon industry obvious in shallow depth. Interpolation across long distances or extrapolation into depth is unfavourable, because this would ignore structural features, inhomogeneity's in the crust or other local effects like topography. For this reasons geomechanical numerical modelling is the favourable method to quantify orientations and magnitudes of the 3D stress field for a geothermal reservoir. A geomechanical-numerical modelling, estimating the 3D absolute stress state, requires the initial stress state as model constraints. But in-situ stress measurements within or close by a potential reservoir are rare. For that reason a larger regional geomechanical-numerical model is necessary, which derive boundary conditions for the wanted local reservoir model. Such a large scale model has to be tested against in-situ stress measurements, orientations and magnitudes. Other suitable and available data, like GPS measurements or fault slip rates are useful to constrain kinematic boundary conditions. This stepwise approach from regional to local scale takes all stress field factors into account, from first over second up to third order. As an example we present a large scale crustal and upper mantle 3D-geomechanical-numerical model of the Alberta Basin and the surroundings, which is constructed to describe continuously the full stress tensor. In-situ stress measurements are the most likely data, because they deliver the most direct information's of the stress field and they provide insights into different depths, a

  6. 3D Dynamic Earthquake Fracture Simulation (Test Case)

    NASA Astrophysics Data System (ADS)

    Korkusuz Öztürk, Yasemin; Meral Özel, Nurcan; Ando, Ryosuke

    2016-04-01

    A 3D dynamic earthquake fracture simulation is being developed for the fault structures which are non-planar to understand heterogeneous stress states in the Marmara Sea. Locating in a seismic gap, a large earthquake is expected in the center of the Sea of Marmara. Concerning the fact that more than 14 million inhabitants of İstanbul, located very closely to the Marmara Sea, the importance of the analysis of the Central Marmara Sea is extremely high. A few 3D dynamic earthquake fracture studies have been already done in the Sea of Marmara for pure right lateral strike-slip stress regimes (Oglesby and Mai, 2012; Aochi and Ulrich, 2015). In this study, a 3D dynamic earthquake fracture model with heterogeneous stress patches from the TPV5, a SCEC code validation case, is adapted. In this test model, the fault and the ground surfaces are gridded by a scalene triangulation technique using GMSH program. For a grid size changing between 0.616 km and 1.050 km the number of elements for the fault surface is 1984 and for the ground surface is 1216. When these results are compared with Kaneko's results for TPV5 from SPECFEM3D, reliable findings could be observed for the first 6.5 seconds (stations on the fault) although a stability problem is encountered after this time threshold. To solve this problem grid sizes are made smaller, so the number of elements increase 7986 for the fault surface and 4867 for the ground surface. On the other hand, computational problems arise in that case, since the computation time is directly proportional to the number of total elements and the required memory also increases with the square of that. Therefore, it is expected that this method can be adapted for less coarse grid cases, regarding the main difficulty coming from the necessity of an effective supercomputer and run time limitations. The main objective of this research is to obtain 3D dynamic earthquake rupture scenarios, concerning not only planar and non-planar faults but also

  7. 3D mapping and simulation of Geneva Lake environmental data

    NASA Astrophysics Data System (ADS)

    Villard, Roch; Maignan, Michel; Kanevski, Mikhail; Rapin, Francois; Klein, Audrey

    2010-05-01

    The Geneva Lake is the biggest alpine and subalpine lake in central Europe. The depth of this lake is 309 meters and its total volume of water is 89 billions m3. It takes, on average, around twelve years so that waters of the lake are completely brewed. Furthermore the Geneva lake waters are rich in dissolved substances as carbonate, sulfate. The quantity of particles in suspension in the lake, which mainly arrived from the Rhône, is nowadays around height million of tones. The International Commission for the Leman Lake (CIPEL) works about the improvement of the quality of this lake since 1962. In the present study three dimensional environmental data (temperature, oxygen and nitrate) which cover the period from 1954 to 2008, for a total of 27'500 cases are investigated. We are interested to study the evolution of the temperature of the lake because there is an impact on the reproduction of fishes and also because the winter brewing of the water makes the re-oxygenation of deep-water. In order that biological balance is maintained in a lake, there must be enough oxygen in the water. Moreover, we work on nitrate distribution and evolution because contributions in fertilizers cause eutrophication of lake. The data are very numerous when we consider the time series, some of them with more than 300 occurrences, but there are between 2 and 15 data available for spatial cartography. The basic methodology used for the analysis, mapping and simulations of 3D patterns of environmental data is based on geostatistical predictions (family of kriging models) and conditional stochastic simulations. Spatial and temporal variability, 3D monitoring networks changing over time, make this study challenging. An important problem is also to make interpolation/simulations over a long period of time, like ten years. One way used to overcome this problem, consists in using a weighted average of ten variograms during this period. 3D mapping was carried out using environment data for

  8. First 3-D simulations of meteor plasma dynamics and turbulence

    NASA Astrophysics Data System (ADS)

    Oppenheim, Meers M.; Dimant, Yakov S.

    2015-02-01

    Millions of small but detectable meteors hit the Earth's atmosphere every second, creating trails of hot plasma that turbulently diffuse into the background atmosphere. For over 60 years, radars have detected meteor plasmas and used these signals to infer characteristics of the meteoroid population and upper atmosphere, but, despite the importance of meteor radar measurements, the complex processes by which these plasmas evolve have never been thoroughly explained or modeled. In this paper, we present the first fully 3-D simulations of meteor evolution, showing meteor plasmas developing instabilities, becoming turbulent, and inhomogeneously diffusing into the background ionosphere. These instabilities explain the characteristics and strength of many radar observations, in particular the high-resolution nonspecular echoes made by large radars. The simulations reveal how meteors create strong electric fields that dig out deep plasma channels along the Earth's magnetic fields. They also allow researchers to explore the impacts of the intense winds and wind shears, commonly found at these altitudes, on meteor plasma evolution. This study will allow the development of more sophisticated models of meteor radar signals, enabling the extraction of detailed information about the properties of meteoroid particles and the atmosphere.

  9. 3D radiative transfer in colliding wind binaries: Application of the SimpleX algorithm to 3D SPH simulations

    NASA Astrophysics Data System (ADS)

    Madura, Thomas; Clementel, Nicola; Kruip, Chael; Icke, Vincent; Gull, Theodore

    2014-09-01

    We present the first results of full 3D radiative transfer simulations of the colliding stellar winds in a massive binary system. We accomplish this by applying the SIMPLEX algorithm for 3D radiative transfer on an unstructured Delaunay grid to recent 3D smoothed particle hydrodynamics (SPH) simulations of the colliding winds in the binary system η Carinae. We use SIMPLEX to obtain detailed ionization fractions of hydrogen and helium, in 3D, at the resolution of the original SPH simulations. We show how the SIMPLEX simulations can be used to generate synthetic spectral data cubes for comparison to data obtained with the Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph as part of a multi-cycle program to map changes in η Car's extended interacting wind structures across one binary cycle. Comparison of the HST observations to the SIMPLEX models can help lead to more accurate constraints on the orbital, stellar, and wind parameters of the η Car system, such as the primary's mass-loss rate and the companion's temperature and luminosity. While we initially focus specifically on the η Car binary, the numerical methods employed can be applied to numerous other colliding wind (WR140, WR137, WR19) and dusty 'pinwheel' (WR104, WR98a) binary systems. One of the biggest remaining mysteries is how dust can form and survive in such systems that contain a hot, luminous O star. Coupled with 3D hydrodynamical simulations, SIMPLEX simulations have the potential to help determine the regions where dust can form and survive in these unique objects.

  10. 3D Numerical Simulation on the Rockslide Generated Tsunamis

    NASA Astrophysics Data System (ADS)

    Chuang, M.; Wu, T.; Wang, C.; Chu, C.

    2013-12-01

    The rockslide generated tsunami is one of the most devastating nature hazards. However, the involvement of the moving obstacle and dynamic free-surface movement makes the numerical simulation a difficult task. To describe both the fluid motion and solid movement at the same time, we newly developed a two-way fully-coupled moving solid algorithm with 3D LES turbulent model. The free-surface movement is tracked by volume of fluid (VOF) method. The two-step projection method is adopted to solve the Navier-Stokes type government equations. In the new moving solid algorithm, a fictitious body force is implicitly prescribed in MAC correction step to make the cell-center velocity satisfied with the obstacle velocity. We called this method the implicit velocity method (IVM). Because no extra terms are added to the pressure Poission correction, the pressure field of the fluid part is stable, which is the key of the two-way fluid-solid coupling. Because no real solid material is presented in the IVM, the time marching step is not restricted to the smallest effective grid size. Also, because the fictitious force is implicitly added to the correction step, the resulting velocity is accurate and fully coupled with the resulting pressure field. We validated the IVM by simulating a floating box moving up and down on the free-surface. We presented the time-history obstacle trajectory and compared it with the experimental data. Very accurate result can be seen in terms of the oscillating amplitude and the period (Fig. 1). We also presented the free-surface comparison with the high-speed snapshots. At the end, the IVM was used to study the rock-slide generated tsunamis (Liu et al., 2005). Good validations on the slide trajectory and the free-surface movement will be presented in the full paper. From the simulation results (Fig. 2), we observed that the rockslide generated waves are manly caused by the rebounding waves from two sides of the sliding rock after the water is dragging

  11. Studying methane migration mechanisms at Walker Ridge, Gulf of Mexico, via 3D methane hydrate reservoir modeling

    SciTech Connect

    Nole, Michael; Daigle, Hugh; Mohanty, Kishore; Cook, Ann; Hillman, Jess

    2015-12-15

    We have developed a 3D methane hydrate reservoir simulator to model marine methane hydrate systems. Our simulator couples highly nonlinear heat and mass transport equations and includes heterogeneous sedimentation, in-situ microbial methanogenesis, the influence of pore size contrast on solubility gradients, and the impact of salt exclusion from the hydrate phase on dissolved methane equilibrium in pore water. Using environmental parameters from Walker Ridge in the Gulf of Mexico, we first simulate hydrate formation in and around a thin, dipping, planar sand stratum surrounded by clay lithology as it is buried to 295mbsf. We find that with sufficient methane being supplied by organic methanogenesis in the clays, a 200x pore size contrast between clays and sands allows for a strong enough concentration gradient to significantly drop the concentration of methane hydrate in clays immediately surrounding a thin sand layer, a phenomenon that is observed in well log data. Building upon previous work, our simulations account for the increase in sand-clay solubility contrast with depth from about 1.6% near the top of the sediment column to 8.6% at depth, which leads to a progressive strengthening of the diffusive flux of methane with time. By including an exponentially decaying organic methanogenesis input to the clay lithology with depth, we see a decrease in the aqueous methane supplied to the clays surrounding the sand layer with time, which works to further enhance the contrast in hydrate saturation between the sand and surrounding clays. Significant diffusive methane transport is observed in a clay interval of about 11m above the sand layer and about 4m below it, which matches well log observations. The clay-sand pore size contrast alone is not enough to completely eliminate hydrate (as observed in logs), because the diffusive flux of aqueous methane due to a contrast in pore size occurs slower than the rate at which methane is supplied via organic methanogenesis

  12. Parallel Cartesian grid refinement for 3D complex flow simulations

    NASA Astrophysics Data System (ADS)

    Angelidis, Dionysios; Sotiropoulos, Fotis

    2013-11-01

    A second order accurate method for discretizing the Navier-Stokes equations on 3D unstructured Cartesian grids is presented. Although the grid generator is based on the oct-tree hierarchical method, fully unstructured data-structure is adopted enabling robust calculations for incompressible flows, avoiding both the need of synchronization of the solution between different levels of refinement and usage of prolongation/restriction operators. The current solver implements a hybrid staggered/non-staggered grid layout, employing the implicit fractional step method to satisfy the continuity equation. The pressure-Poisson equation is discretized by using a novel second order fully implicit scheme for unstructured Cartesian grids and solved using an efficient Krylov subspace solver. The momentum equation is also discretized with second order accuracy and the high performance Newton-Krylov method is used for integrating them in time. Neumann and Dirichlet conditions are used to validate the Poisson solver against analytical functions and grid refinement results to a significant reduction of the solution error. The effectiveness of the fractional step method results in the stability of the overall algorithm and enables the performance of accurate multi-resolution real life simulations. This material is based upon work supported by the Department of Energy under Award Number DE-EE0005482.

  13. Higher Order Finite Element Methods for Compositional Simulation in 3D Multiphase Multicomponent Flow

    NASA Astrophysics Data System (ADS)

    Shahraeeni, E.; Firoozabadi, A.

    2012-12-01

    We present a 3D model for fully compositional multi-phase multi-component flow in porous media with species transfer between the phases. Phase properties are modeled with the Peng-Robinson equation of state. Because phase properties may exhibit strong discontinuities, we approximate the mass transport update by the means of discontinuous Galerkin method. Pressure and velocity fields are continuous across the whole domain of solution, which is guaranteed by using the mixed hybrid finite element method. Complexity of the flow necessitates the use of either very fine mesh or higher-order schemes. The use of higher-order finite element methods significantly reduces numerical dispersion and grid orientation effects that plague traditional finite difference methods. We have shown that in 3D the convergence rate of our scheme is twice as first order method and the CPU time may improve up to three orders of magnitude for the same level of accuracy. Our numerical model facilitates accurate simulation of delicate feature of compositional flow like fingering and CO2 injection in complex reservoirs for a broad range of applications, including CO2 sequestration in finite aquifer and water flooded reservoirs with transfer of all species between the phases.

  14. 3-D numerical simulations of volcanic ash transport and deposition

    NASA Astrophysics Data System (ADS)

    Suzuki, Y. J.; Koyaguchi, T.

    2012-12-01

    During an explosive volcanic eruption, volcanic gas and pyroclasts are ejected from the volcanic vent. The pyroclasts are carried up within a convective plume, advected by the surrounding wind field, and sediment on the ground depending on their terminal velocity. The fine ash are expected to have atmospheric residence, whereas the coarser particles form fall deposits. Accurate modeling of particle transport and deposition is of critical importance from the viewpoint of disaster prevention. Previously, some particle-tracking models (e.g., PUFF) and advection-diffusion models (e.g., TEPHRA2 and FALL3D) tried to forecast particle concentration in the atmosphere and particle loading at ground level. However, these models assumed source conditions (the grain-size distribution, plume height, and mass release location) based on the simple 1-D model of convective plume. In this study, we aim to develop a new 3-D model which reproduces both of the dynamics of convective plume and the ash transport. The model is designed to describe the injection of eruption cloud and marker particles from a circular vent above a flat surface into the stratified atmosphere. Because the advection is the predominant mechanism of particle transport near the volcano, the diffusive process is not taken into account in this model. The distribution of wind velocity is given as an initial condition. The model of the eruption cloud dynamics is based on the 3-D time-dependent model of Suzuki et al. (2005). We apply a pseudo-gas model to calculate the eruption cloud dynamics: the effect of particle separation on the cloud dynamics is not considered. In order to reproduce the drastic change of eruption cloud density, we change the effective gas constant and heat capacity of the mixture in the equation of state for ideal gases with the mixing ratio between the ejected material and entrained air. In order to calculate the location and movement of ash particles, the present model employs Lagrangian marker

  15. 20 and 3D Numerical Simulations of Flux Cancellation

    NASA Technical Reports Server (NTRS)

    Karpen, Judith T.; DeVore, C.; Antiochos, S. K.; Linton, M. G.

    2009-01-01

    Cancellation of magnetic flux in the solar photosphere and chromosphere has been linked observationally and theoretically to a broad range of solar activity, from filament channel formation to CME initiation. Because this phenomenon is typically measured at only a single layer in the atmosphere, in the radial (line of sight) component of the magnetic field, the actual processes behind this observational signature are ambiguous. It is clear that reconnection is involved in some way, but the location of the reconnection sites and associated connectivity changes remain uncertain in most cases. We are using numerical modeling to demystify flux cancellation, beginning with the simplest possible configuration: a subphotospheric Lundquist flux tube surrounded by a potential field, immersed in a gravitationally stratified atmosphere, spanning many orders of magnitude in plasma beta. In this system, cancellation is driven slowly by a 2-cell circulation pattern imposed in the convection zone, such that the tops of the cells are located around the beta= 1 level (Le., the photosphere) and the flows converge and form a downdraft at the polarity inversion line; note however that no flow is imposed along the neutral line. We will present the results of 2D and 3D MHD-AMR simulations of flux cancellation, in which the flux at the photosphere begins in either an unsheared or sheared state. In all cases, a lOW-lying flux rope is formed by reconnection at the polarity inversion line within a few thousand seconds. The flux rope remains stable and does not rise, however, in contrast to models which do not include the presence of significant mass loading.

  16. 2D and 3D Numerical Simulations of Flux Cancellation

    NASA Technical Reports Server (NTRS)

    Karpen, Judith T.; DeVore, C.; Antiochos, S. K.; Linton, M. G.

    2009-01-01

    Cancellation of magnetic flux in the solar photosphere and chromosphere has been linked observationally and theoretically to a broad range of solar activity, from filament channel formation to CME initiation. Because this phenomenon is typically measured at only a single layer in the atmosphere, in the radial (line of sight) component of the magnetic field, the actual processes behind this observational signature are ambiguous. It is clear that reconnection is involved in some way, but the location of the reconnection sites and associated connectivity changes remain uncertain in most cases. We are using numerical modeling to demystify flux cancellation, beginning with the simplest possible configuration: a subphotospheric Lundquist flux tube surrounded by a potential field, immersed in a gravitationally stratified atmosphere, spanning many orders of magnitude in plasma beta. In this system, cancellation is driven slowly by a 2-cell circulation pattern imposed in the convection zone, such that the tops of the cells are located around the beta=1 level (i.e., the photosphere) and the flows converge and form a downdraft at the polarity inversion line; note however that no flow is imposed along the neutral line. We will present the results of 2D and 3D MHD-AMR simulations of flux cancellation, in which the flux at the photosphere begins in either an unsheared or sheared state. In all cases, a low-lying flux rope is formed by reconnection at the polarity inversion line within a few thousand seconds. The flux rope remains stable and does not rise, however, in contrast to models which do not include the presence of significant mass loading.

  17. 3D modelling of a dolomitized syn-sedimentary structure: an exhumed potential analogue of hydrocarbon reservoir.

    NASA Astrophysics Data System (ADS)

    Martinelli, Mattia; Franceschi, Marco; Massironi, Matteo; Bistacchi, Andrea; Di Cuia, Raffaele; Rizzi, Alessandro

    2016-04-01

    further increase the potential creation of potential hydrocarbon traps. These complex conditions are visible in a syn-sedimentary structure spectacularly exposed on the Monte Testo (Trentino, Italy). In this contribution, we present a 3D geo-model of this structure, obtained with SKUA-gOcad, based on 3D photogrammetric modelling, detailed geological mapping and structural analysis, porosity analysis carried out on representative sections, and geostatistical simulation of porosity on dolomitized bodies. Thanks to the 3D model we obtained: i) a thickness map of the Rotzo Formation that allow us to understand which faults were active during the deposition of the formation and which areas could have been more suitable for hydrocarbon accumulation; ii) a geometric and volumetric model of the structure that permitted us to study the porosity distribution and to define the potential volume of hydrocarbons that could be hosted by a similar structure. These results were eventually extrapolated to the entire platform, providing clues on the hydrocarbon potential of similar buried geologic bodies.

  18. Petroleum reservoir data for testing simulation models

    SciTech Connect

    Lloyd, J.M.; Harrison, W.

    1980-09-01

    This report consists of reservoir pressure and production data for 25 petroleum reservoirs. Included are 5 data sets for single-phase (liquid) reservoirs, 1 data set for a single-phase (liquid) reservoir with pressure maintenance, 13 data sets for two-phase (liquid/gas) reservoirs and 6 for two-phase reservoirs with pressure maintenance. Also given are ancillary data for each reservoir that could be of value in the development and validation of simulation models. A bibliography is included that lists the publications from which the data were obtained.

  19. Multigrid methods with applications to reservoir simulation

    SciTech Connect

    Xiao, Shengyou

    1994-05-01

    Multigrid methods are studied for solving elliptic partial differential equations. Focus is on parallel multigrid methods and their use for reservoir simulation. Multicolor Fourier analysis is used to analyze the behavior of standard multigrid methods for problems in one and two dimensions. Relation between multicolor and standard Fourier analysis is established. Multiple coarse grid methods for solving model problems in 1 and 2 dimensions are considered; at each coarse grid level we use more than one coarse grid to improve convergence. For a given Dirichlet problem, a related extended problem is first constructed; a purification procedure can be used to obtain Moore-Penrose solutions of the singular systems encountered. For solving anisotropic equations, semicoarsening and line smoothing techniques are used with multiple coarse grid methods to improve convergence. Two-level convergence factors are estimated using multicolor. In the case where each operator has the same stencil on each grid point on one level, exact multilevel convergence factors can be obtained. For solving partial differential equations with discontinuous coefficients, interpolation and restriction operators should include information about the equation coefficients. Matrix-dependent interpolation and restriction operators based on the Schur complement can be used in nonsymmetric cases. A semicoarsening multigrid solver with these operators is used in UTCOMP, a 3-D, multiphase, multicomponent, compositional reservoir simulator. The numerical experiments are carried out on different computing systems. Results indicate that the multigrid methods are promising.

  20. 3D GRMHD and GRPIC Simulations of Disk-Jet Coupling and Emission

    SciTech Connect

    Nishikawa, Ken-Ichi; Mizuno, Y.; Watson, M.; Hardee, P.; Fuerst, S.; Wu, K.; Fishman, G.J.; /NASA, Marshall

    2006-12-19

    We investigate jet formation in black-hole systems using 3-D General Relativistic Particle-In-Cell (GRPIC) and 3-D GRMHD simulations. GRPIC simulations, which allow charge separations in a collisionless plasma, do not need to invoke the frozen condition as in GRMHD simulations. 3-D GRPIC simulations show that jets are launched from Kerr black holes as in 3-D GRMHD simulations, but jet formation in the two cases may not be identical. Comparative study of black hole systems with GRPIC and GRMHD simulations with the inclusion of radiate transfer will further clarify the mechanisms that drive the evolution of disk-jet systems.

  1. 3-D simulation of urban warming in Tokyo and proposal of air-cooled city project

    SciTech Connect

    Saitoh, T.S.; Yamada, Noboru

    1999-07-01

    Recent computer projection of the urban warming in Tokyo metropolitan area around the year 2030 showed the authors that the urban temperature near Otemachi, heart of Tokyo, will exceed 43{+-}2 degree Celsius (110 degree Fahrenheit) at 6 p.m. in the summer. In the present paper, modeling and 3-D simulation results of urban warming in the Tokyo metropolitan area were presented and discussed. Furthermore, the effect of the reduction of carbon dioxide (CO{sub 2}) emissions was discussed by using a newly developed 3-D simulation code. Finally, the authors proposed a new concept; cool-air ventilated city project, which alleviates the urban warming, air pollution, and urban discomfort. In this project, the urban outdoor and indoor spaces are ventilated by clean cooled-air, which is produced in the rural or mountainous regions located far away from the urban area. Water of a huge reservoir is cooled below 4 degree Celsius in winter by utilizing sky radiation cooling and will be kept until the summer for indoor and outdoor space cooling. In this study, the feasibility of this system was discussed.

  2. Classification and quantification of pore shapes in sandstone reservoir rocks with 3-D X-ray micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Schmitt, M.; Halisch, M.; Müller, C.; Fernandes, C. P.

    2015-12-01

    Recent years have seen a growing interest in the characterization of the pore morphologies of reservoir rocks and how the spatial organization of pore traits affects the macro behaviour of rock-fluid systems. With the availability of 3-D high-resolution imaging (e.g. μ-CT), the detailed quantification of particle shapes has been facilitated by progress in computer science. Here, we show how the shapes of irregular rock particles (pores) can be classified and quantified based on binary 3-D images. The methodology requires the measurement of basic 3-D particle descriptors and a shape classification that involves the similarity of artificial objects, which is based on main pore network detachments and 3-D sample sizes. The results were validated for three sandstones (S1, S2 and S3) from distinct reservoirs, and most of the pore shapes were found to be plate- and cube-like. Furthermore, this study generalizes a practical way to correlate specific particle shapes, such as rods, blades, cuboids, plates and cubes, to characterize asymmetric particles of any material type with 3-D image analysis.

  3. Assessing Methane Migration Mechanisms at Walker Ridge, Gulf of Mexico, via 3D Methane Hydrate Reservoir Modeling

    NASA Astrophysics Data System (ADS)

    Nole, M.; Daigle, H.; Mohanty, K. K.; Hillman, J. I. T.; Cook, A.

    2015-12-01

    We employ a 3D methane hydrate reservoir simulator to model marine methane hydrate systems. Our simulator couples highly nonlinear heat and mass transport equations and includes heterogeneous sedimentation, in-situ organic methanogenesis, and the influences of both pore size contrast and salt exclusion from the hydrate phase on solubility gradients. Using environmental parameters of Walker Ridge, Gulf of Mexico, we first simulate hydrate formation in and around a thin, dipping, planar sand stratum surrounded by clay lithology as it is buried to 295mbsf. With sufficient methane supplied by methanogenesis in the clays, a 200x sand-clay pore size contrast allows for a strong enough concentration gradient to significantly drop the concentration of hydrate in clays immediately surrounding a thin sand, a phenomenon observed in corresponding well log data. Building upon previous work, our simulations account for a depth-wise increase in sand-clay solubility contrast from about 1.6% near the seafloor to 8.6% at depth, progressively strengthening the diffusive flux of methane with time. An exponentially decaying methanogenesis input to the clay lithology decreases the methane supplied to clays surrounding the sand layer with time, further enhancing the sand-clay hydrate saturation contrast. Significant diffusive methane transport occurs in a clay interval of about 11m above the sand and 4m below it, matching well log observations. Clay-sand pore size contrast alone is not enough to create hydrate-free zones seen in logs, because the corresponding diffusive methane flux is slower than the rate at which methanogenesis supplies methane. Therefore, it is likely that additional mechanisms are at play, notably bound water activity reduction in clays. Three-dimensionality allows for inclusion of lithologic heterogeneities, which focus flow and allow for heterogeneity in locally dominant methane migration mechanisms. Incorporating recent 3D seismic data to inform the model

  4. Reservoir simulation of a high viscous crude and strong water drive reservoir in Sarawak, Malaysia

    SciTech Connect

    Ramli, A.

    1995-10-01

    The Bokor field is located offshore Sarawak, Malaysia and is one of the largest fields in the Baram Delta Province. The A3/6 group of reservoirs is the largest among the Bokor reservoir groups. The reservoir comprises a series of multiple, stacked, well-developed, fluviomarine sandstones connected to a large aquifer. Production from this reservoir started in 1983 and since then some 15 MMstb of oil have been produced. To better understand the production performance, displacement mechanism and further development opportunities in this high viscous crude (10 cP) and strong water drive reservoir, a 3D sector reservoir simulation has been carried out. The model comprises 8640 active grid blocks, with 14 strings completed on four reservoir units with separate fluid contacts. The layering system and grid dimensions were found to be critical in the history matching process, which was supported by a X-sectional study carried out prior to embarking on the 3D model. Based on the history match, remaining oil was identified on the eastern flank, at the top of each sand unit (due to water under-running) and in the downdip area due to the existing crestal oriented development. The history matched model was subsequently used to aid further development planning and to formulate a cost-effective reservoir management strategy. Various development scenarios were tested in this 3D model, which include infill drilling, horizontal wells and pressure maintenance by water injection. This paper describes the various steps taken to obtain a good history match over the 10 years of production history and discusses the findings of the prediction runs.

  5. 3-D General Relativistic MHD Simulations of Generating Jets

    NASA Astrophysics Data System (ADS)

    Nishikawa, K.-I.; Koide, S.; Shibata, K.; Kudoh, T.; Frank, J.; Sol, H.

    1999-12-01

    We have investigated the dynamics of an accretion disk around Schwarzschild black holes initially threaded by a uniform poloidal magnetic field in a non-rotating corona (either in a steady-state infalling state or in hydrostatic equilibrium) around a non-rotating black hole using a 3-D GRMHD with the ``axisymmetry'' along the z-direction. Magnetic field is tightly twisted by the rotation of the disk, and plasmas in the shocked region of the disk are accelerated by J x B force to form bipolar relativistic jets. In order to investigate variabilities of generated relativistic jets and magnetic field structure inside jets, we have performed calculations using the 3-D GRMHD code with a full 3-dimensional system. We will investigate how the third dimension affects the global disk dynamics and jet generation.

  6. 3-D General Relativistic MHD Simulations of Generating Jets

    NASA Astrophysics Data System (ADS)

    Nishikawa, K.-I.; Koide, S.; Shibata, K.; Kudoh, T.; Sol, H.; Hughes, J. P.

    2000-12-01

    We have investigated the dynamics of an accretion disk around Schwarzschild black holes initially threaded by a uniform poloidal magnetic field in a non-rotating corona (either in a steady-state infalling state) around a non-rotating black hole using a 3-D GRMHD with the ``axisymmetry'' along the z-direction. Magnetic field is tightly twisted by the rotation of the disk, and plasmas in the shocked region of the disk are accelerated by J x B force to form bipolar relativistic jets. In order to investigate variabilities of generated relativistic jets and magnetic field structure inside jets, we have performed calculations using the 3-D GRMHD code with a full 3-dimensional system. We will investigate how the third dimension affects the global disk dynamics and jet generation.

  7. DREAM3D simulations of inner-belt dynamics

    SciTech Connect

    Cunningham, Gregory Scott

    2015-05-26

    A 1973 paper by Lyons and Thorne explains the two-belt structure for electrons in the inner magnetosphere as a balance between inward radial diffusion and loss to the atmosphere, where the loss to the atmosphere is enabled by pitch-angle scattering from Coulomb and wave-particle interactions. In the 1973 paper, equilibrium solutions to a decoupled set of 1D radial diffusion equations, one for each value of the first invariant of motion, μ, were computed to produce the equilibrium two-belt structure. Each 1D radial diffusion equation incorporated an L-and μ-dependent `lifetime' due to the Coulomb and wave-particle interactions. This decoupling of the problem is appropriate under the assumption that radial diffusion is slow in comparison to pitch-angle scattering. However, for some values of μ and L the lifetime associated with pitch-angle scattering is comparable to the timescale associated with radial diffusion, suggesting that the true equilibrium solutions might reflect `coupled modes' involving pitch-angle scattering and radial diffusion and thus requiring a 3D diffusion model. In the work we show here, we have computed the equilibrium solutions using our 3D diffusion model, DREAM3D, that allows for such coupling. We find that the 3D equilibrium solutions are quite similar to the solutions shown in the 1973 paper when we use the same physical models for radial diffusion and pitch-angle scattering from hiss. However, we show that the equilibrium solutions are quite sensitive to various aspects of the physics model employed in the 1973 paper that can be improved, suggesting that additional work needs to be done to understand the two-belt structure.

  8. Using 3-D Numerical Weather Data in Piloted Simulations

    NASA Technical Reports Server (NTRS)

    Daniels, Taumi S.

    2016-01-01

    This report describes the process of acquiring and using 3-D numerical model weather data sets in NASA Langley's Research Flight Deck (RFD). A set of software tools implement the process and can be used for other purposes as well. Given time and location information of a weather phenomenon of interest, the user can download associated numerical weather model data. These data are created by the National Oceanic and Atmospheric Administration (NOAA) High Resolution Rapid Refresh (HRRR) model, and are then processed using a set of Mathworks' Matlab(TradeMark) scripts to create the usable 3-D weather data sets. Each data set includes radar re ectivity, water vapor, component winds, temperature, supercooled liquid water, turbulence, pressure, altitude, land elevation, relative humidity, and water phases. An open-source data processing program, wgrib2, is available from NOAA online, and is used along with Matlab scripts. These scripts are described with sucient detail to make future modi cations. These software tools have been used to generate 3-D weather data for various RFD experiments.

  9. Method and simulation to study 3D crosstalk perception

    NASA Astrophysics Data System (ADS)

    Khaustova, Dar'ya; Blondé, Laurent; Huynh-Thu, Quan; Vienne, Cyril; Doyen, Didier

    2012-03-01

    To various degrees, all modern 3DTV displays suffer from crosstalk, which can lead to a decrease of both visual quality and visual comfort, and also affect perception of depth. In the absence of a perfect 3D display technology, crosstalk has to be taken into account when studying perception of 3D stereoscopic content. In order to improve 3D presentation systems and understand how to efficiently eliminate crosstalk, it is necessary to understand its impact on human perception. In this paper, we present a practical method to study the perception of crosstalk. The approach consists of four steps: (1) physical measurements of a 3DTV, (2) building of a crosstalk surface based on those measurements and representing specifically the behavior of that 3TV, (3) manipulation of the crosstalk function and application on reference images to produce test images degraded by crosstalk in various ways, and (4) psychophysical tests. Our approach allows both a realistic representation of the behavior of a 3DTV and the easy manipulation of its resulting crosstalk in order to conduct psycho-visual experiments. Our approach can be used in all studies requiring the understanding of how crosstalk affects perception of stereoscopic content and how it can be corrected efficiently.

  10. Use of 3D Seismic Azimuthal Iso-Frequency Volumes for the Detection and Characterization of High Porosity/Permeability Zones in Carbonate Reservoirs

    NASA Astrophysics Data System (ADS)

    Toelle, Brian E.

    Among the most important properties controlling the production from conventional oil and gas reservoirs is the distribution of porosity and permeability within the producing geologic formation. The geometry of the pore space within these reservoirs, and the permeability associated with this pore space geometry, impacts not only where production can occur and at what flow rates but can also have significant influence on many other rock properties. Zones of high matrix porosity can result in an isotropic response for certain reservoir properties whereas aligned porosity/permeability, such as open, natural fracture trends, have been shown to result in reservoirs being anisotropic in many properties. The ability to identify zones within a subsurface reservoir where porosity/permeability is significantly higher and to characterize them according to their geometries would be of great significance when planning where new boreholes, particularly horizontal boreholes, should be drilled. The detection and characterization of these high porosity/permeability zones using their isotropic and anisotropic responses may be possible through the analysis of azimuthal (also referred to as azimuth-limited) 3D seismic volumes. During this study the porosity/permeability systems of a carbonate, pinnacle reef within the northern Michigan Basin undergoing enhanced oil recovery were investigated using selected seismic attributes extracted from azimuthal 3D seismic volumes. Based on the response of these seismic attributes an interpretation of the geometry of the porosity/permeability system within the reef was made. This interpretation was supported by well data that had been obtained during the primary production phase of the field. Additionally, 4D seismic data, obtained as part of the CO2 based EOR project, supported reservoir simulation results that were based on the porosity/permeability interpretation.

  11. Multimodal reservoir porosity simulation: An application to a tight oil reservoir

    NASA Astrophysics Data System (ADS)

    Sauvageau, Mathieu; Gloaguen, Erwan; Claprood, Maxime; Lefebvre, René; Bêche, Martin

    2014-08-01

    At appraisal stage of a reservoir characterization, a key step is the inference of the reservoir static properties, such as porosity. In this study, we present a new nested workflow that optimally integrates 3D acoustic impedance and geophysical log data for the estimation of the spatial distribution of reservoir porosity, which is applied to a tight sandstone oil reservoir located in Quebec, Canada. In this workflow, 3D seismic is the main source of spatial information. First, the statistical petrophysical relationship between acoustic impedance and reservoir porosity is established using collocated geophysical log data. Second, a conventional least-squares post-stack inversion of the impedance is computed on the seismic grid. The fit between well log data and numerically computed traces was found to be inaccurate. This leads to the third step, involving a post-stack stochastic impedance inversion using the same seismic traces not only to improve well and trace fit but also to estimate the uncertainty on the inverted impedances. Finally, a Bayesian simulation algorithm adapted to the estimation of a multi-modal porosity distribution is used to simulate realizations of porosity over the entire seismic grid. Results show that the over-smoothing effect of least-squares inversion has a major impact on resource evaluation, especially by not reproducing the high-valued tail of the porosity distribution. The adapted Bayesian algorithm combined with stochastic impedance inversion thus allows a better reproduction of the porosity distribution and improves estimation of the geophysical and geological uncertainty.

  12. The thermal regime of the Campi Flegrei magmatic system reconstructed through 3D numerical simulations

    NASA Astrophysics Data System (ADS)

    Di Renzo, Valeria; Wohletz, Kenneth; Civetta, Lucia; Moretti, Roberto; Orsi, Giovanni; Gasparini, Paolo

    2016-12-01

    We illustrate a quantitative conductive/convective thermal model incorporating a wide range of geophysical, petrological, geological, geochemical and isotopical observations that constrain the thermal evolution and present state of the Campi Flegrei caldera (CFc) magmatic system. The proposed model has been computed on the basis of the current knowledge of: (1) the volcanic and magmatic history of the volcano over the last 44 ka, (2) its underlying crustal structure, and (3) the physical properties of the erupted magmas. 3D numerical simulations of heat conduction and convection within heterogeneous rock/magma materials with evolving heat sources and boundary conditions that simulate magma rise from a deep (≥ 8 km depth) to shallow (2-6 km) reservoirs, magma chamber formation, magma extrusion, caldera collapse, and intra-caldera hydrothermal convection, have been carried out. The evolution of the CFc magmatic system through time has been simulated through different steps related to its changes in terms of depth, location and size of magma reservoirs and their replenishment. The thermal modeling results show that both heat conduction and convection have played an important role in the CFc thermal evolution, although with different timing. The simulated present heat distribution is in agreement with the measured geothermal profiles (Agip, 1987), reproduces the thermal gradient peaks at the CFc margins in correspondence to the anomalies in surface gradients (Corrado et al., 1998), and suggests temperatures of 700 °C at depth of 4 km in the central portion of the caldera, in agreement with the estimated temperature for the brittle-ductile transition (Hill, 1992).

  13. Development of hydraulic fracture network propagation model in shale gas reservoirs: 2D, single-phase and 3D, multi-phase model development, parametric studies, and verification

    NASA Astrophysics Data System (ADS)

    Ahn, Chong Hyun

    The most effective method for stimulating shale gas reservoirs is a massive hydraulic fracture treatment. Recent analysis using microseismic technology have shown that complex fracture networks are commonly created in the field as a result of the stimulation of shale wells. The interaction between pre-existing natural fractures and the propagating hydraulic fracture is a critical factor affecting the created complex fracture network; however, many existing numerical models simulate only planar hydraulic fractures without considering the pre-existing fractures in the formation. The shale formations already contain a large number of natural fractures, so an accurate fracture propagation model needs to be developed to optimize the fracturing process. In this research, we first characterized the mechanics of hydraulic fracturing and fluid flow in the shale gas reservoir. Then, a 2D, single-phase numerical model and a 3D, 2-phase coupled model were developed, which integrate dynamic fracture propagation, interactions between hydraulic fractures and pre-existing natural fractures, fracture fluid leakoff, and fluid flow in a petroleum reservoir. By using the developed model, we conducted parametric studies to quantify the effects of treatment rate, treatment size, fracture fluid viscosity, differential horizontal stress, natural fracture spacing, fracture toughness, matrix permeability, and proppant size on the geometry of the hydraulic fracture network. The findings elucidate important trends in hydraulic fracturing of shale reservoirs that are useful in improving the design of treatments for specific reservoir settings.

  14. Building a 3D Virtual Liver: Methods for Simulating Blood Flow and Hepatic Clearance on 3D Structures

    PubMed Central

    Rezania, Vahid; Tuszynski, Jack

    2016-01-01

    In this paper, we develop a spatio-temporal modeling approach to describe blood and drug flow, as well as drug uptake and elimination, on an approximation of the liver. Extending on previously developed computational approaches, we generate an approximation of a liver, which consists of a portal and hepatic vein vasculature structure, embedded in the surrounding liver tissue. The vasculature is generated via constrained constructive optimization, and then converted to a spatial grid of a selected grid size. Estimates for surrounding upscaled lobule tissue properties are then presented appropriate to the same grid size. Simulation of fluid flow and drug metabolism (hepatic clearance) are completed using discretized forms of the relevant convective-diffusive-reactive partial differential equations for these processes. This results in a single stage, uniformly consistent method to simulate equations for blood and drug flow, as well as drug metabolism, on a 3D structure representative of a liver. PMID:27649537

  15. 3D Reservoir Modeling of Semutang Gas Field: A lonely Gas field in Chittagong-Tripura Fold Belt, with Integrated Well Log, 2D Seismic Reflectivity and Attributes.

    NASA Astrophysics Data System (ADS)

    Salehin, Z.; Woobaidullah, A. S. M.; Snigdha, S. S.

    2015-12-01

    Bengal Basin with its prolific gas rich province provides needed energy to Bangladesh. Present energy situation demands more Hydrocarbon explorations. Only 'Semutang' is discovered in the high amplitude structures, where rest of are in the gentle to moderate structures of western part of Chittagong-Tripura Fold Belt. But it has some major thrust faults which have strongly breached the reservoir zone. The major objectives of this research are interpretation of gas horizons and faults, then to perform velocity model, structural and property modeling to obtain reservoir properties. It is needed to properly identify the faults and reservoir heterogeneities. 3D modeling is widely used to reveal the subsurface structure in faulted zone where planning and development drilling is major challenge. Thirteen 2D seismic and six well logs have been used to identify six gas bearing horizons and a network of faults and to map the structure at reservoir level. Variance attributes were used to identify faults. Velocity model is performed for domain conversion. Synthetics were prepared from two wells where sonic and density logs are available. Well to seismic tie at reservoir zone shows good match with Direct Hydrocarbon Indicator on seismic section. Vsh, porosity, water saturation and permeability have been calculated and various cross plots among porosity logs have been shown. Structural modeling is used to make zone and layering accordance with minimum sand thickness. Fault model shows the possible fault network, those liable for several dry wells. Facies model have been constrained with Sequential Indicator Simulation method to show the facies distribution along the depth surfaces. Petrophysical models have been prepared with Sequential Gaussian Simulation to estimate petrophysical parameters away from the existing wells to other parts of the field and to observe heterogeneities in reservoir. Average porosity map for each gas zone were constructed. The outcomes of the research

  16. 3-D Simulations of NSTAR Ion Thruster Plasma Interactions

    NASA Technical Reports Server (NTRS)

    Wang, J.; Brophy, J.; Polk, J.; Brinza, D.

    1996-01-01

    Described is a Particle-in-Cell with Monte Carlo Collision code developed to perform detailed three-dimensional ion thruster simulations. To capture the full kinetic behavior of ion thruster plumes, both the electrons and ions are treated as test particles. Simulation results are given of the NSTAR ion thruster under ground test and in space conditions. Numerical results are compared.

  17. Modeling Airport Ground Operations using Discrete Event Simulation (DES) and X3D Visualization

    DTIC Science & Technology

    2008-03-01

    studies, because it offers a number of features as for example: 12 1. Open source 2. Character animation support (CAL3D) 3. Game engine with...Simulation, DES, Simkit, Diskit, Viskit, Savage, XML, Distributed Interactive Simulation, DIS, Blender , X3D Edit 16. PRICE CODE 17. SECURITY...10 5. Blender Authoring Tool

  18. Simple 3-D stimulus for motion parallax and its simulation.

    PubMed

    Ono, Hiroshi; Chornenkyy, Yevgen; D'Amour, Sarah

    2013-01-01

    Simulation of a given stimulus situation should produce the same perception as the original. Rogers et al (2009 Perception 38 907-911) simulated Wheeler's (1982, PhD thesis, Rutgers University, NJ) motion parallax stimulus and obtained quite different perceptions. Wheeler's observers were unable to reliably report the correct direction of depth, whereas Rogers's were. With three experiments we explored the possible reasons for the discrepancy. Our results suggest that Rogers was able to see depth from the simulation partly due to his experience seeing depth with random dot surfaces.

  19. Classification and quantification of pore shapes in sandstone reservoir rocks with 3-D X-ray micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Schmitt, Mayka; Halisch, Matthias; Müller, Cornelia; Peres Fernandes, Celso

    2016-02-01

    Recent years have seen a growing interest in the characterization of the pore morphologies of reservoir rocks and how the spatial organization of pore traits affects the macro behavior of rock-fluid systems. With the availability of 3-D high-resolution imaging, such as x-ray micro-computed tomography (µ-CT), the detailed quantification of particle shapes has been facilitated by progress in computer science. Here, we show how the shapes of irregular rock particles (pores) can be classified and quantified based on binary 3-D images. The methodology requires the measurement of basic 3-D particle descriptors (length, width, and thickness) and a shape classification that involves the similarity of artificial objects, which is based on main pore network detachments and 3-D sample sizes. Two main pore components were identified from the analyzed volumes: pore networks and residual pore ganglia. A watershed algorithm was applied to preserve the pore morphology after separating the main pore networks, which is essential for the pore shape characterization. The results were validated for three sandstones (S1, S2, and S3) from distinct reservoirs, and most of the pore shapes were found to be plate- and cube-like, ranging from 39.49 to 50.94 % and from 58.80 to 45.18 % when the Feret caliper descriptor was investigated in a 10003 voxel volume. Furthermore, this study generalizes a practical way to correlate specific particle shapes, such as rods, blades, cuboids, plates, and cubes to characterize asymmetric particles of any material type with 3-D image analysis.

  20. Tensor3D: A computer graphics program to simulate 3D real-time deformation and visualization of geometric bodies

    NASA Astrophysics Data System (ADS)

    Pallozzi Lavorante, Luca; Dirk Ebert, Hans

    2008-07-01

    Tensor3D is a geometric modeling program with the capacity to simulate and visualize in real-time the deformation, specified through a tensor matrix and applied to triangulated models representing geological bodies. 3D visualization allows the study of deformational processes that are traditionally conducted in 2D, such as simple and pure shears. Besides geometric objects that are immediately available in the program window, the program can read other models from disk, thus being able to import objects created with different open-source or proprietary programs. A strain ellipsoid and a bounding box are simultaneously shown and instantly deformed with the main object. The principal axes of strain are visualized as well to provide graphical information about the orientation of the tensor's normal components. The deformed models can also be saved, retrieved later and deformed again, in order to study different steps of progressive strain, or to make this data available to other programs. The shape of stress ellipsoids and the corresponding Mohr circles defined by any stress tensor can also be represented. The application was written using the Visualization ToolKit, a powerful scientific visualization library in the public domain. This development choice, allied to the use of the Tcl/Tk programming language, which is independent on the host computational platform, makes the program a useful tool for the study of geometric deformations directly in three dimensions in teaching as well as research activities.

  1. Demonstration of a Novel, Integrated, Multi-Scale Procedure for High-Resolution 3D Reservoir Characterization and Improved CO2-EOR/Sequestration Management, SACROC Unit

    SciTech Connect

    Scott R. Reeves

    2007-09-30

    relational model to predict porosity and permeability profiles from well logs at each well location, and a 3D geostatistical variogram to generate the reservoir characterization over the reservoir volume of interest. A reservoir simulation model was built based upon this characterization and history-matched without making significant changes to it, thus validating the procedure. While not the same procedure as originally planned, the procedure ultimately employed proved successful and demonstrated that the general concepts proposed (i.e., data mining and advanced pattern recognition methods) have the flexibility to achieve the reservoir characterization objectives sought even with imperfect or incomplete data.

  2. 3-D Spreadsheet Simulation of a Modern Particle Detector

    ERIC Educational Resources Information Center

    Scott, Alan J.

    2004-01-01

    A spreadsheet simulation of a modern particle detector has been developed and can be readily used as an instructional tool in the physics classroom. The spreadsheet creates a three-dimensional model that can be rotated and helical trajectories can be highlighted. An associated student worksheet is also presented.

  3. 3-D MHD disk wind simulations of protostellar jets

    NASA Astrophysics Data System (ADS)

    Staff, Jan E.; Koning, Nico; Ouyed, Rachid; Tanaka, Kei; Tan, Jonathan C.

    2016-01-01

    We present the results of large scale, three-dimensional magnetohydrodynamics simulations of disk winds for different initial magnetic field configurations. The jets are followed from the source to distances, which are resolvable by HST and ALMA observations. Our simulations show that jets are heated along their length by many shocks. The mass of the protostar is a free parameter that can be inserted in the post processing of the data, and we apply the simulations to both low mass and high mass protostars. For the latter we also compute the expected diagnostics when the outflow is photoionized by the protostar. We compute the emission lines that are produced, and find excellent agreement with observations. For a one solar mass protostar, we find the jet width to be between 20 and 30 au while the maximum velocities perpendicular to the jet are found to be 100 km s-1. The initially less open magnetic field configuration simulations result in a wider, two-component jet; a cylindrically shaped outer jet surrounding a narrow and much faster, inner jet. For the initially most open magnetic field configuration the kink mode creates a narrow corkscrew-like jet without a clear Keplerian rotation profile and even regions where we observe rotation opposite to the disk (counter-rotating). This is not seen in the less open field configurations.

  4. 3D Continuum-Particle Simulations for Multiscale Hydrodynamics

    NASA Astrophysics Data System (ADS)

    Wijesinghe, Sanith; Hornung, Richard; Garcia, Alejandro; Hadjiconstantinou, Nicolas

    2001-06-01

    An adaptive mesh and algorithmic refinement (AMAR) scheme to model multi-scale, continuum-particle hydrodynamic flows is presented. AMAR ensures the particle description is applied exclusively in regions with high flow gradients and discontinous material interfaces, i.e. regions where the continuum flow assumptions are typically invalid. Direct Simulation Monte Carlo (DSMC) is used to model the particle regions on the finest grid of the adaptive hierarchy. The continuum flow is modelled using the compressible flow Euler equations and is solved using a second order Godunov scheme. Coupling is achieved by conservation of fluxes across the continuum-particle grid boundaries. The AMAR data structures are supported by a C++ object oriented framework (Structured Adaptive Mesh Refinement Application Infrastructure - SAMRAI) which allows for efficient parallel implementation. The scheme also extends to simulations of gas mixtures. Results for test cases are compared with theory and experiment.

  5. ROAR: A 3-D tethered rocket simulation code

    SciTech Connect

    York, A.R. II; Ludwigsen, J.S.

    1992-04-01

    A high-velocity impact testing technique, utilizing a tethered rocket, is being developed at Sandia National Laboratories. The technique involves tethering a rocket assembly to a pivot location and flying it in a semicircular trajectory to deliver the rocket and payload to an impact target location. Integral to developing this testing technique is the parallel development of accurate simulation models. An operational computer code, called ROAR (Rocket-on-a-Rope), has been developed to simulate the three-dimensional transient dynamic behavior of the tether and motor/payload assembly. This report presents a discussion of the parameters modeled, the governing set of equations, the through-time integration scheme, and the input required to set up a model. Also included is a sample problem and a comparison with experimental results.

  6. A 3D Geostatistical Mapping Tool

    SciTech Connect

    Weiss, W. W.; Stevenson, Graig; Patel, Ketan; Wang, Jun

    1999-02-09

    This software provides accurate 3D reservoir modeling tools and high quality 3D graphics for PC platforms enabling engineers and geologists to better comprehend reservoirs and consequently improve their decisions. The mapping algorithms are fractals, kriging, sequential guassian simulation, and three nearest neighbor methods.

  7. Photorealistic 3D omni-directional stereo simulator

    NASA Astrophysics Data System (ADS)

    Reiners, Dirk; Cruz-Neira, Carolina; Neumann, Carsten

    2015-03-01

    While a lot of areas in VR have made significant advances, visual rendering in VR is often not quite keeping up with the state of the art. There are many reasons for this, but one way to alleviate some of the issues is by using ray tracing instead of rasterization for image generation. Contrary to popular belief, ray tracing is a realistic, competitive technology nowadays. This paper looks at the pros and cons of using ray tracing and demonstrates the feasibility of employing it using the example of a helicopter flight simulator image generator.

  8. 3D modeling of gas/water distribution in water-bearing carbonate gas reservoirs: the Longwangmiao gas field, China

    NASA Astrophysics Data System (ADS)

    Ou, Chenghua; Li, ChaoChun; Ma, Zhonggao

    2016-10-01

    A water-bearing carbonate gas reservoir is an important natural gas resource being developed worldwide. Due to the long-term water/rock/gas interaction during geological evolution, complex gas/water distribution has formed under the superposed effect of sedimentary facies, reservoir space facies and gravity difference of fluid facies. In view of these challenges, on the basis of the conventional three-stage modeling method, this paper presents a modelling method controlled by four-stage facies to develop 3D model of a water-bearing carbonate gas reservoir. Key to this method is the reservoir property modelling controlled by two-stage facies, and the fluid property modelling controlled by another two-stage facies. The prerequisite of this method is a reliable database obtained from solid geological investigation. On the basis of illustrating the principles of the modelling method controlled by four-stage facies, this paper further implements systematically modeling of the heterogeneous gas/water distribution of the Longwangmiao carbonate formation in the Moxi-Gaoshiti area, Sichuan basin, China.

  9. Numerical grid generation in 3D Euler-flow simulation

    NASA Astrophysics Data System (ADS)

    Boerstoel, J. W.

    1988-04-01

    The technical problems with grid generation are analyzed and an overview of proposed solutions is given. The usefulness of grid-generation techniques, for the numerical simulation of Euler (and Navier-Stokes) flows around complex three-dimensional aerodynamic configurations, is illustrated. It is shown that the core of the grid-generation problem is a topology problem. The following remarks are sketched: grid generation is a subtask in a numerical simulation of a flow in industrial and research environments; the design requirements of a grid generation concern the geometrical imput, the desired grid as output, the technical means to control grid resolution and quality and turnaround time performance; the construction of a blocked grid can be subdivided in a block-decomposition task and a grid-point distribution task. A technique for using connectivity relations to define conventions about local coordinate systems in edges, faces and blocks is presented. Experiences are reported and an example concerning a 96-blocked grid around a complex aerodynamic configuration is given. Concepts for improvements in the presented technique are discussed.

  10. Linking continuum mechanics and 3D discrete dislocation simulations

    SciTech Connect

    El-Azab, A. A.; Fivel, M.

    1998-10-18

    A technique is developed for linking the methods of discrete dislocation dynamics simulation and finite element to treat elasto-plasticity problems. The overall formulation views the plastically deforming crystal as an elastic crystal with continuously changing dislocation microstructure which is tracked by the numerical dynamics simulation. The FEM code needed in this regard is based on linear elasticity only. This formulation presented here is focused on a continuous updating of the outer shape of the crystal, for possible regeneration of the FEM mesh, and adjustment of the surface geometry, in particular the surface normal. The method is expected to be potentially applicable to the nano- indentation experiments, where the zone around the indenter-crystal contact undergoes significant permanent deformation, the rigorous determination of which is very important to the calculation of the indentation print area and in turn, the surface hardness. Furthermore, the technique is expected to account for the plastic history of the surface displacement under the indenter. Other potential applications are mentioned in the text.

  11. 3-D description of fracture surfaces and stress-sensitivity analysis for naturally fractured reservoirs

    SciTech Connect

    Zhang, S.Q.; Jioa, D.; Meng, Y.F.; Fan, Y.

    1997-08-01

    Three kinds of reservoir cores (limestone, sandstone, and shale with natural fractures) were used to study the effect of morphology of fracture surfaces on stress sensitivity. The cores, obtained from the reservoirs with depths of 2170 to 2300 m, have fractures which are mated on a large scale, but unmated on a fine scale. A specially designed photoelectric scanner with a computer was used to describe the topography of the fracture surfaces. Then, theoretical analysis of the fracture closure was carried out based on the fracture topography generated. The scanning results show that the asperity has almost normal distributions for all three types of samples. For the tested samples, the fracture closure predicted by the elastic-contact theory is different from the laboratory measurements because plastic deformation of the aspirates plays an important role under the testing range of normal stresses. In this work, the traditionally used elastic-contact theory has been modified to better predict the stress sensitivity of reservoir fractures. Analysis shows that the standard deviation of the probability density function of asperity distribution has a great effect on the fracture closure rate.

  12. Development of 3D beam-beam simulation for the Tevatron

    SciTech Connect

    Stern, E.; Amundson, J.; Spentzouris, P.; Valishev, A.; Qiang, J.; Ryne, R.; /LBL, Berkeley

    2007-06-01

    We present status of development of a 3D Beam-Beam simulation code for simulating the Fermilab Tevatron collider. The essential features of the code are 3D particle-in-cell Poisson solver for calculating the Beam-Beam electromagnetic interactions with additional modules for linear optics, machine impedance and chromaticity, and multiple bunch tracking. The simulations match synchrobetatron oscillations measured at the VEPP-2M collider. The impedance calculations show beam instability development consistent with analytic expressions.

  13. Dynamic 3D simulations of earthquakes on en echelon faults

    USGS Publications Warehouse

    Harris, R.A.; Day, S.M.

    1999-01-01

    One of the mysteries of earthquake mechanics is why earthquakes stop. This process determines the difference between small and devastating ruptures. One possibility is that fault geometry controls earthquake size. We test this hypothesis using a numerical algorithm that simulates spontaneous rupture propagation in a three-dimensional medium and apply our knowledge to two California fault zones. We find that the size difference between the 1934 and 1966 Parkfield, California, earthquakes may be the product of a stepover at the southern end of the 1934 earthquake and show how the 1992 Landers, California, earthquake followed physically reasonable expectations when it jumped across en echelon faults to become a large event. If there are no linking structures, such as transfer faults, then strike-slip earthquakes are unlikely to propagate through stepovers >5 km wide. Copyright 1999 by the American Geophysical Union.

  14. 3D Simulation and Validation of Tube Piercing Process

    NASA Astrophysics Data System (ADS)

    Ceretti, Elisabetta; Giardini, Claudio; Attanasio, Aldo

    2007-05-01

    In many cases the development of analytical or simulative models of actual production processes can help in improving the product quality furnishing defect-free parts. In particular, when tube piercing processes are referring to, the main problem that can arise is the low quality of the internal tube surface. This type of defect cannot be eliminated during the successive production phases so compromising the final part quality. It is possible to overcome this problem by placing in the correct position the internal plug which defines the internal tube diameter. This position greatly depends on where the tube material begins to break due the acting internal stresses. This phenomenon is called Mannesmann effect. The farther the plug from the Mannesmann cone formation, the higher the oxidation of the internal tube surface. On the contrary the closer the plug, the higher the wear of the plug. In actual practice an on-line control of the position of the Mannesmann cone is impossible to be implemented. In the past, the Authors have developed a model to help the production line technicians in determining where to place the plug. This model was a two dimensional representation of the actual phenomenon, and it has already been proved to correctly represent the actual tube behavior since it was validated by comparing its results with experiments. Using the results of a wide simulation campaign, a neural network was trained and now it is used as an on-line plug position definition support. In the present paper the results obtained using a fully three dimensional model of the process are reported. This model will allow to confirm some simplifying assumption made in the 2D model definition and to study the tube behavior when it reaches and moves on the plug, too. Some comparisons with practical evidences are reported.

  15. Petroleum Systems of South Kara Basin: 3D stratigraphic simulation and basin modeling results

    NASA Astrophysics Data System (ADS)

    Malysheva, S.; Vasilyev, V.; Verzhbitsky, V.; Ananyev, V.; Murzin, R.; Komissarov, D.; Kosenkova, N.; Roslov, Yu.

    2012-04-01

    Petroleum systems of South Kara Basin are still poorly studied and hydrocarbon resource estimates vary depending on geological models and understanding of the basin evolution. The main purpose of the regional studies of South Kara Basin was to produce a consistent model, which would be able to explain the existence of the fields discovered in the area as well as to determine the most favorable hydrocarbon accumulation zones in the study area for further exploration. In the study 3D stratigraphic simulation and basin modeling of South Kara Basin was carried out. The stratigraphic simulation results, along with geological, geophysical and geochemical data for the inland areas of Yamal and Gydan peninsulas and South Kara islands enabled to predict the lithological composition and distribution of source rocks, reservoirs and seals in the Kara Sea offshore area. Based on the basin modeling results hydrocarbon accumulations may occur in the reservoir facies of the wide stratigraphic range from Jurrasic to Cretaceous. The main source for the hydrocarbons, accumulated in the South Kara Basin Neocomian and Cenomanian reservoirs are the J3-K1 (the northward extension of Bazhenov Formation and its analogs of West Siberia), as well as J1 and probably J2 shales with predominantly marine type of kerogen (type II). Thermal and burial history restorations show that Lower Cretaceous (Aptian-Albian) sediments enriched with terrigenous organic matter (kerogen of type III) and containing coaly layers could not produce the hydrocarbon volumes to fill the giant Rusanovskoye and Leningradskoye gas-condensate fields as the K1 source rocks are not mature enough. The modeling results, in particular, suggest that the geologic conditions in the South Kara Basin are favorable for further discoveries of giant fields. Although gas accumulations are predominating in the basin, oil-and-gascondensate fields (not a pure oil fields though) with sufficient part of liquid hydrocarbons might be present

  16. Detailed 3D Simulation of the GEM-based detector

    NASA Astrophysics Data System (ADS)

    Bhattacharya, P.; Biswas, S.; Mohanty, B.; Majumdar, N.; Mukhopadhyay, S.

    2016-10-01

    The operation of Micro Pattern Gaseous Detectors (MPGDs) has often suffered from effects such as distortion of the electric field due to space charge, despite their widespread use in particle-physics and nuclear-physics experiments, astro-particle research, medical imaging, material science etc. To keep distortions due to space-charge at a manageable level, a lower ion feedback is required while maintaining substantial detector gain and good resolution. Thus, a proper optimization of the detector geometry, field configuration and gas mixtures are required to have a higher electron transparency and lower ion backflow. In our work, Garfield simulation framework has been adopted as a tool to evaluate the fundamental features of Gas Electron Multiplier (GEM). Our study begins with the computation of electrostatic field and its variation with different geometrical and electrical parameters using the neBEM toolkit. Different efficient algorithms have been implemented to increase the computational efficiency of the field solver. Finally, ion backflow and electron transparency of single and quadruple GEMs with different geometry and field configurations suitable for the ALICE-TPC, have been studied.

  17. The Virtual Radiopharmacy Laboratory: A 3-D Simulation for Distance Learning

    ERIC Educational Resources Information Center

    Alexiou, Antonios; Bouras, Christos; Giannaka, Eri; Kapoulas, Vaggelis; Nani, Maria; Tsiatsos, Thrasivoulos

    2004-01-01

    This article presents Virtual Radiopharmacy Laboratory (VR LAB), a virtual laboratory accessible through the Internet. VR LAB is designed and implemented in the framework of the VirRAD European project. This laboratory represents a 3D simulation of a radio-pharmacy laboratory, where learners, represented by 3D avatars, can experiment on…

  18. Real-Time Climate Simulations in the Interactive 3D Game Universe Sandbox ²

    NASA Astrophysics Data System (ADS)

    Goldenson, N. L.

    2014-12-01

    Exploration in an open-ended computer game is an engaging way to explore climate and climate change. Everyone can explore physical models with real-time visualization in the educational simulator Universe Sandbox ² (universesandbox.com/2), which includes basic climate simulations on planets. I have implemented a time-dependent, one-dimensional meridional heat transport energy balance model to run and be adjustable in real time in the midst of a larger simulated system. Universe Sandbox ² is based on the original game - at its core a gravity simulator - with other new physically-based content for stellar evolution, and handling collisions between bodies. Existing users are mostly science enthusiasts in informal settings. We believe that this is the first climate simulation to be implemented in a professionally developed computer game with modern 3D graphical output in real time. The type of simple climate model we've adopted helps us depict the seasonal cycle and the more drastic changes that come from changing the orbit or other external forcings. Users can alter the climate as the simulation is running by altering the star(s) in the simulation, dragging to change orbits and obliquity, adjusting the climate simulation parameters directly or changing other properties like CO2 concentration that affect the model parameters in representative ways. Ongoing visuals of the expansion and contraction of sea ice and snow-cover respond to the temperature calculations, and make it accessible to explore a variety of scenarios and intuitive to understand the output. Variables like temperature can also be graphed in real time. We balance computational constraints with the ability to capture the physical phenomena we wish to visualize, giving everyone access to a simple open-ended meridional energy balance climate simulation to explore and experiment with. The software lends itself to labs at a variety of levels about climate concepts including seasons, the Greenhouse effect

  19. 3-D RESERVOIR AND STOCHASTIC FRACTURE NETWORK MODELING FOR ENHANCED OIL RECOVERY, CIRCLE RIDGE PHOSPHORIA/TENSLEEP RESERVOIR, WIND RIVER RESERVATION, ARAPAHO AND SHOSHONE TRIBES, WYOMING

    SciTech Connect

    Paul La Pointe; Jan Hermanson; Robert Parney; Thorsten Eiben; Mike Dunleavy; Ken Steele; John Whitney; Darrell Eubanks; Roger Straub

    2002-11-18

    This report describes the results made in fulfillment of contract DE-FG26-00BC15190, ''3-D Reservoir and Stochastic Fracture Network Modeling for Enhanced Oil Recovery, Circle Ridge Phosphoria/Tensleep Reservoir, Wind River Reservation, Arapaho and Shoshone Tribes, Wyoming''. The goal of this project is to improve the recovery of oil from the Tensleep and Phosphoria Formations in Circle Ridge Oilfield, located on the Wind River Reservation in Wyoming, through an innovative integration of matrix characterization, structural reconstruction, and the characterization of the fracturing in the reservoir through the use of discrete fracture network models. Fields in which natural fractures dominate reservoir permeability, such as the Circle Ridge Field, often experience sub-optimal recovery when recovery processes are designed and implemented that do not take advantage of the fracture systems. For example, a conventional waterflood in a main structural block of the Field was implemented and later suspended due to unattractive results. It is estimated that somewhere less than 20% of the OOIP in the Circle Ridge Field have been recovered after more than 50 years' production. Marathon Oil Company identified the Circle Ridge Field as an attractive candidate for several advanced IOR processes that explicitly take advantage of the natural fracture system. These processes require knowledge of the distribution of matrix porosity, permeability and oil saturations; and understanding of where fracturing is likely to be well-developed or poorly developed; how the fracturing may compartmentalize the reservoir; and how smaller, relatively untested subthrust fault blocks may be connected to the main overthrust block. For this reason, the project focused on improving knowledge of the matrix properties, the fault block architecture and to develop a model that could be used to predict fracture intensity, orientation and fluid flow/connectivity properties. Knowledge of matrix properties was

  20. Recent advances in 3D computed tomography techniques for simulation and navigation in hepatobiliary pancreatic surgery.

    PubMed

    Uchida, Masafumi

    2014-04-01

    A few years ago it could take several hours to complete a 3D image using a 3D workstation. Thanks to advances in computer science, obtaining results of interest now requires only a few minutes. Many recent 3D workstations or multimedia computers are equipped with onboard 3D virtual patient modeling software, which enables patient-specific preoperative assessment and virtual planning, navigation, and tool positioning. Although medical 3D imaging can now be conducted using various modalities, including computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and ultrasonography (US) among others, the highest quality images are obtained using CT data, and CT images are now the most commonly used source of data for 3D simulation and navigation image. If the 2D source image is bad, no amount of 3D image manipulation in software will provide a quality 3D image. In this exhibition, the recent advances in CT imaging technique and 3D visualization of the hepatobiliary and pancreatic abnormalities are featured, including scan and image reconstruction technique, contrast-enhanced techniques, new application of advanced CT scan techniques, and new virtual reality simulation and navigation imaging.

  1. Build-and-fill sequences: How subtle paleotopography affects 3-D heterogeneity of potential reservoir facies

    USGS Publications Warehouse

    McKirahan, J.R.; Goldstein, R.H.; Franseen, E.K.

    2005-01-01

    This study analyzes the three-dimensional variability of a 20-meter-thick section of Pennsylvanian (Missourian) strata over a 600 km2 area of northeastern Kansas, USA. It hypothesizes that sea-level changes interact with subtle variations in paleotopography to influence the heterogeneity of potential reservoir systems in mixed carbonate-silidclastic systems, commonly produdng build-and-fill sequences. For this analysis, ten lithofacies were identified: (1) phylloid algal boundstone-packstone, (2) skeletal wackestone-packstone, (3) peloidal, skeletal packstone, (4) sandy, skeletal grainstone-packstone, (5) oolite grainstone-packstone, (6) Osagia-brachiopod packstone, (7) fossiliferous siltstone, (8) lenticular bedded-laminated siltstone and fine sandstone, (9) organic-rich mudstone and coal, and (10) massive mudstone. Each facies can be related to depositional environment and base-level changes to develop a sequence stratigraphy consisting of three sequence boundaries and two flooding surfaces. Within this framework, eighteen localities are used to develop a threedimensional framework of the stratigraphy and paleotopography. The studied strata illustrate the model of "build-and-fill". In this example, phylloid algal mounds produce initial relief, and many of the later carbonate and silidclastic deposits are focused into subtle paleotopographic lows, responding to factors related to energy, source, and accommodation, eventually filling the paleotopography. After initial buildup of the phylloid algal mounds, marine and nonmarine siliciclastics, with characteristics of both deltaic lobes and valley fills, were focused into low areas between mounds. After a sea-level rise, oolitic carbonates formed on highs and phylloid algal facies accumulated in lows. A shift in the source direction of siliciclastics resulted from flooding or filling of preexisting paleotopographic lows. Fine-grained silidclastics were concentrated in paleotopographic low areas and resulted in clay

  2. Geomechanically Coupled Simulation of Flow in Fractured Reservoirs

    NASA Astrophysics Data System (ADS)

    Barton, C.; Moos, D.; Hartley, L.; Baxter, S.; Foulquier, L.; Holl, H.; Hogarth, R.

    2012-12-01

    Capturing the necessary and sufficient detail of reservoir hydraulics to accurately evaluate reservoir behavior remains a significant challenge to the exploitation and management of fracture-dominated geothermal reservoirs. In these low matrix permeability reservoirs, stimulation response is controlled largely by the properties of natural and induced fracture networks, which are in turn controlled by the in situ stresses, the fracture distribution and connectivity and the hydraulic behavior of the fractures. This complex interaction of fracture flow systems with the present-day stress field compounds the problem of developing an effective and efficient simulation to characterize, model and predict fractured reservoir performance. We discuss here a case study of the integration of geological, geophysical, geomechanical, and reservoir engineering data to characterize the in situ stresses, the natural fracture network and the controls on fracture permeability in geothermal reservoirs. A 3D geomechanical reservoir model includes constraints on stress magnitudes and orientations, and constraints on mechanical rock properties and the fractures themselves. Such a model is essential to understanding reservoir response to stimulation and production in low matrix permeability, fracture-dominated reservoirs. The geomechanical model for this study was developed using petrophysical, drilling, and wellbore image data along with direct well test measurements and was mapped to a 3D structural grid to facilitate coupled simulation of the fractured reservoir. Wellbore image and stimulation test data were used along with microseismic data acquired during the test to determine the reservoir fracture architecture and to provide control points for a realistic inter-connected discrete fracture network. As most fractures are stress-sensitive, their hydraulic conductivities will change with changes in bottomhole flowing and reservoir pressures, causing variations in production profiles

  3. 13. Symposium on reservoir simulation: Proceedings

    SciTech Connect

    1995-12-31

    This is a conference proceedings which deals with the latest developments and trends in reservoir simulation techniques and modeling. It includes papers dealing with multiphase flow in oil and gas wells; flow calculation methods in deviated and horizontal wells; fluid flow in fractured reservoirs; and simulation techniques for enhanced recovery and well stimulation processes. Most papers provide case studies using the various computer models or computer systems, including numerous studies on parallel processing equipment.

  4. 3D simulations of multipacting in the 56 MHz SRF cavity

    SciTech Connect

    Wu Q.; Belomestnykh, S.; Ge, L.; Ko, K.; Li, Z.; Ng, C.; Xiao, L.

    2012-05-20

    The 56 MHz SRF Quarter-Wave Resonator (QWR) is designed for RHIC as a storage cavity to improve the collider performance. 2D multipacting simulation has been done for the cavity alone. Ripples were added to the outer body of the cavity for multipacting suppression based on the simulation findings. During operation, there will be four higher order mode (HOM) couplers. All of these components will be exposed to high RF fields. In this paper we compare 2D and 3D codes simulation results for multipacting in the cavity. We also report 3D simulation results for multipacting simulation at the couplers.

  5. 3-D seismic evidence of the effects of carbonate karst collapse on overlying clastic stratigraphy and reservoir compartmentalization

    SciTech Connect

    Hardage, B.A.; Carr, D.L.; Simmons, J.L. Jr.; Jons, R.A.; Lancaster, D.E.; Elphick, R.Y.; Pendleton, V.M.

    1996-09-01

    A multidisciplinary team, composed of stratigraphers, petrophysicists, reservoir engineers, and geophysicists, studied a portion of Boonsville gas field in the Fort Worth Basin of north-central Texas to determine how modern techniques can be combined to understand the mechanisms by which fluvio-deltaic depositional processes create reservoir compartmentalization in a low- to moderate-accommodation basin. An extensive database involving well logs, cores, production, and pressure data from more than 200 wells, 26 mi{sup 2} of 3-D seismic data, vertical seismic profiles, and checkshots was assembled to support this investigation. The authors found the most important geologic influence on stratigraphy and reservoir compartmentalization in this basin to be the existence of numerous karst collapse chimneys over the area covered. These near-vertical karst collapses originated in, or near, the deep Ordovician-age Ellenburger carbonate section and created vertical chimneys extending as high as 2,500 ft above their point of origin, causing significant disruptions in the overlying clastic strata.

  6. Representativeness of 2D models to simulate 3D unstable variable density flow in porous media

    NASA Astrophysics Data System (ADS)

    Knorr, Bastian; Xie, Yueqing; Stumpp, Christine; Maloszewski, Piotr; Simmons, Craig T.

    2016-11-01

    Variable density flow in porous media has been studied primarily using numerical models because it is a semi-chaotic and transient process. Most of these studies have been 2D, owing to the computational restrictions on 3D simulations, and the ability to observe variable density flow in 2D experimentation. However, it is recognised that variable density flow is a three-dimensional process. A 3D system may cause weaker variable density flow than a 2D system due to stronger dispersion, but may also result in bigger fingers and hence stronger variable density flow because of more space for fingers to coalesce. This study aimed to determine the representativeness of 2D modelling to simulate 3D variable density flow. 3D homogeneous sand column experiments were conducted at three different water flow velocities with three different bromide tracer solutions mixed with methanol resulting in different density ratios. Both 2D axisymmetric and 3D numerical simulations were performed to reproduce experimental data. Experimental results showed that the magnitude of variable density flow increases with decreasing flow rates and decreasing density ratios. The shapes of the observed breakthrough curves differed significantly from those produced by 2D axisymmetric and 3D simulations. Compared to 2D simulations, the onset of instabilities was delayed but the growth was more pronounced in 3D simulations. Despite this difference, both 2D axisymmetric and 3D models successfully simulated mass recovery with high efficiency (between 77% and 99%). This study indicates that 2D simulations are sufficient to understand integrated features of variable density flow in homogeneous sand column experiments.

  7. Characterization of fluvial sedimentology for reservoir simulation modeling

    SciTech Connect

    Henriquez, A.; Tyler, K.J.; Hurst, A. )

    1990-09-01

    This paper presents a critical study of 3D stochastic simulation of a fluvial reservoir and of the transfer of the geological model to a reservoir simulation grid. The stochastic model is conditioned by sand-body thickness and position in wellbores. Geological input parameters-sand-body orientation and width/thickness ratios-are often difficult to determine, and are invariably subject to interpretation. Net/gross ratio (NGR) and sand-body thickness are more easily estimated. Sand-body connectedness varies, depending on the modeling procedure; however, a sedimentary process-related model gives intermediate values for connectedness between the values for a regular packing model and the stochastic model. The geological model is transferred to a reservoir simulation grid by use of transmissibility multipliers and an NGR value for each block. The transfer of data smooths out much of the detailed geological information, and the calculated recovery factors are insensitive to the continuity measured in the geological model. Hence, the authors propose improvements to the interface between geological and reservoir simulation models.

  8. The Effects of 3D Computer Simulation on Biology Students' Achievement and Memory Retention

    ERIC Educational Resources Information Center

    Elangovan, Tavasuria; Ismail, Zurida

    2014-01-01

    A quasi experimental study was conducted for six weeks to determine the effectiveness of two different 3D computer simulation based teaching methods, that is, realistic simulation and non-realistic simulation on Form Four Biology students' achievement and memory retention in Perak, Malaysia. A sample of 136 Form Four Biology students in Perak,…

  9. Reservoir lithofacies analysis using 3D seismic data in dissimilarity space

    NASA Astrophysics Data System (ADS)

    Bagheri, M.; Riahi, M. A.; Hashemi, H.

    2013-06-01

    Seismic data interpretation is one of the most important steps in exploration seismology. Seismic facies analysis (SFA) with emphasis on lithofacies can be used to extract more information about structures and geology, which results in seismic interpretation enhancement. Facies analysis is based on unsupervised and supervised classification using seismic attributes. In this paper, supervised classification by a support vector machine using well logs and seismic attributes is applied. Dissimilarity as a new measuring space is employed, after which classification is carried out. Often, SFA is carried out in a feature space in which each dimension stands as a seismic attribute. Different facies show lots of class overlap in the feature space; hence, high classification error values are reported. Therefore, decreasing class overlap before classification is a necessary step to be targeted. To achieve this goal, a dissimilarity space is initially created. As a result of the definition of the new space, the class overlap between objects (seismic samples) is reduced and hence the classification can be done reliably. This strategy causes an increase in the accuracy of classification, and a more trustworthy lithofacies analysis is attained. For applying this method, 3D seismic data from an oil field in Iran were selected and the results obtained by a support vector classifier (SVC) in dissimilarity space are presented, discussed and compared with the SVC applied in conventional feature space.

  10. Integration of reservoir simulation and geomechanics

    NASA Astrophysics Data System (ADS)

    Zhao, Nan

    Fluid production from tight and shale gas formations has increased significantly, and this unconventional portfolio of low-permeability reservoirs accounts for more than half of the gas produced in the United States. Stimulation and hydraulic fracturing are critical in making these systems productive, and hence it is important to understand the mechanics of the reservoir. When modeling fractured reservoirs using discrete-fracture network representation, the geomechanical effects are expected to have a significant impact on important reservoir characteristics. It has become more accepted that fracture growth, particularly in naturally fractured reservoirs with extremely low permeability, cannot be reliably represented by conventional planar representations. Characterizing the evolution of multiple, nonplanar, interconnected and possibly nonvertical hydraulic fractures requires hydraulic and mechanical characterization of the matrix, as well as existing latent or healed fracture networks. To solve these challenging problems, a reservoir simulator (Advanced Reactive Transport Simulator (ARTS)) capable of performing unconventional reservoir simulation is developed in this research work. A geomechanical model has been incorporated into the simulation framework with various coupling schemes and this model is used to understand the geomechanical effects in unconventional oil and gas recovery. This development allows ARTS to accept geomechanical information from external geomechanical simulators (soft coupling) or the solution of the geomechanical coupled problem (hard coupling). An iterative solution method of the flow and geomechanical equations has been used in implementing the hard coupling scheme. The hard coupling schemes were verified using one-dimensional and two-dimensional analytical solutions. The new reservoir simulator is applied to learn the influence of geomechanical impact on unconventional oil and gas production in a number of practical recovery scenarios

  11. 3D gravity inversion and thermodynamic modelling reveal properties of shallow silicic magma reservoir beneath Laguna del Maule, Chile

    NASA Astrophysics Data System (ADS)

    Miller, Craig A.; Williams-Jones, Glyn; Fournier, Dominique; Witter, Jeff

    2017-02-01

    Active, large volume, silicic magma systems are potentially the most hazardous form of volcanism on Earth. Knowledge of the location, size, and physical properties of silicic magma reservoirs, is therefore important for providing context in which to accurately interpret monitoring data and make informed hazard assessments. Accordingly, we present the first geophysical image of the Laguna del Maule volcanic field magmatic system, using a novel 3D inversion of gravity data constrained by thermodynamic modelling. The joint analysis of gravity and thermodynamic data allows for a rich interpretation of the magma system, and highlights the importance of considering the full thermodynamic effects on melt density, when interpreting gravity models of active magmatic systems. We image a 30 km3, low density, volatile rich magma reservoir, at around 2 km depth, containing at least 85% melt, hosted within a broader 115 km3 body interpreted as wholly or partially crystallised (>70% crystal) cumulate mush. Our model suggests a magmatic system with shallow, crystal poor magma, overlying deeper, crystal rich magma. Even though a large density contrast (-600 kg/m3) with the surrounding crust exists, the lithostatic load is 50% greater than the magma buoyancy force, suggesting buoyancy alone is insufficient to trigger an eruption. The reservoir is adjacent to the inferred extension of the Troncoso fault and overlies the location of an intruding sill, driving present day deformation. The reservoir is in close proximity to the 2.0 km3 Nieblas (rln) eruption at 2-3 ka, which we calculate tapped approximately 7% of the magma reservoir. However, we suggest that the present day magma system is not large enough to have fed all post-glacial eruptions, and that the location, or size of the system may have migrated or varied over time, with each eruption tapping only a small aliquot of the available magma. The presence of a shallow reservoir of volatile rich, near liquidus magma, in close

  12. An integrated data model for reservoir simulation

    SciTech Connect

    Aydelotte, S.R.

    1994-02-01

    This paper describes the capability of the Epicenter data model to manage reservoir-simulation information, including the spatial model used to describe the properties of the earth and the product-flow network mode used to describe production performance. In addition to data values, the data model describes data creation and quality and provides a reliable means of understanding the source. To use the data model, reservoir-simulation applications need to be rewritten to conform to the data-model nomenclature and conventions. While this is a significant task, the benefit to reservoir simulation practitioners and vendors includes integration of technical applications (such as mapping, well logging, and geophysical interpretation systems), data portability (allowing Vendor A's simulator to use data prepared by Vendor B's preprocessor), and interpretability such as using a third-party optimization package to conduct a series of simulations.

  13. Models for naturally fractured, carbonate reservoir simulations

    SciTech Connect

    Tuncay, K.; Park, A.; Ozkan, G.; Zhan, X.; Ortoleva, P.; Hoak, T.; Sundberg, K.

    1998-12-31

    This report outlines the need for new tools for the simulation of fractured carbonate reservoirs. Several problems are identified that call for the development of new reservoir simulation physical models and numerical techniques. These include: karst and vuggy media wherein Darcy`s and traditional multi-phase flow laws do not apply; the need for predicting the preproduction state of fracturing and stress so that the later response of effective stress-dependent reservoirs can be predicted; and methods for predicting the fracturing and collapse of vuggy and karst reservoirs in response to draw-down pressure created during production. Specific research directions for addressing each problem are outlined and preliminary results are noted.

  14. Three-dimensional (3D) printed endovascular simulation models: a feasibility study

    PubMed Central

    Nesbitt, Craig; McCaslin, James; Bagnall, Alan; Davey, Philip; Bose, Pentop; Williams, Rob

    2017-01-01

    Background Three-dimensional (3D) printing is a manufacturing process in which an object is created by specialist printers designed to print in additive layers to create a 3D object. Whilst there are initial promising medical applications of 3D printing, a lack of evidence to support its use remains a barrier for larger scale adoption into clinical practice. Endovascular virtual reality (VR) simulation plays an important role in the safe training of future endovascular practitioners, but existing VR models have disadvantages including cost and accessibility which could be addressed with 3D printing. Methods This study sought to evaluate the feasibility of 3D printing an anatomically accurate human aorta for the purposes of endovascular training. Results A 3D printed model was successfully designed and printed and used for endovascular simulation. The stages of development and practical applications are described. Feedback from 96 physicians who answered a series of questions using a 5 point Likert scale is presented. Conclusions Initial data supports the value of 3D printed endovascular models although further educational validation is required. PMID:28251121

  15. Quasi-3D Modeling and Efficient Simulation of Laminar Flows in Microfluidic Devices.

    PubMed

    Islam, Md Zahurul; Tsui, Ying Yin

    2016-10-03

    A quasi-3D model has been developed to simulate the flow in planar microfluidic systems with low Reynolds numbers. The model was developed by decomposing the flow profile along the height of a microfluidic system into a Fourier series. It was validated against the analytical solution for flow in a straight rectangular channel and the full 3D numerical COMSOL Navier-Stokes solver for flow in a T-channel. Comparable accuracy to the full 3D numerical solution was achieved by using only three Fourier terms with a significant decrease in computation time. The quasi-3D model was used to model flows in a micro-flow cytometer chip on a desktop computer and good agreement between the simulation and the experimental results was found.

  16. Quasi-3D Modeling and Efficient Simulation of Laminar Flows in Microfluidic Devices

    PubMed Central

    Islam, Md. Zahurul; Tsui, Ying Yin

    2016-01-01

    A quasi-3D model has been developed to simulate the flow in planar microfluidic systems with low Reynolds numbers. The model was developed by decomposing the flow profile along the height of a microfluidic system into a Fourier series. It was validated against the analytical solution for flow in a straight rectangular channel and the full 3D numerical COMSOL Navier-Stokes solver for flow in a T-channel. Comparable accuracy to the full 3D numerical solution was achieved by using only three Fourier terms with a significant decrease in computation time. The quasi-3D model was used to model flows in a micro-flow cytometer chip on a desktop computer and good agreement between the simulation and the experimental results was found. PMID:27706104

  17. New insights on pulsating white dwarfs from 3D radiation-hydrodynamical simulations

    NASA Astrophysics Data System (ADS)

    Tremblay, Pier-Emmanuel; Fontaine, Gilles; Ludwig, Hans-Günter; Gianninas, Alexandros; Kilic, Mukremin

    We have recently computed a grid of 3D radiation-hydrodynamical simulations for the atmosphere of pure-hydrogen DA white dwarfs in the range 5.0 < log g < 9.0. Our grid covers the full ZZ Ceti instability strip where pulsating DA white dwarfs are located. We have significantly improved the theoretical framework to study these objects by removing the free parameters of 1D convection, which were previously a major modeling hurdle. We present improved atmospheric parameter determinations based on spectroscopic fits with 3D model spectra, allowing for an updated definition of the empirical edges of the ZZ Ceti instability strip. Our 3D simulations also precisely predict the depth of the convection zones, narrowing down the internal layers where pulsation are being driven. We hope that these 3D effects will be included in asteroseismic models in the future to predict the region of the HR diagram where white dwarfs are expected to pulsate.

  18. 3D Simulation of External Flooding Events for the RISMC Pathway

    SciTech Connect

    Prescott, Steven; Mandelli, Diego; Sampath, Ramprasad; Smith, Curtis; Lin, Linyu

    2015-09-01

    Incorporating 3D simulations as part of the Risk-Informed Safety Margins Characterization (RISMIC) Toolkit allows analysts to obtain a more complete picture of complex system behavior for events including external plant hazards. External events such as flooding have become more important recently – however these can be analyzed with existing and validated simulated physics toolkits. In this report, we describe these approaches specific to flooding-based analysis using an approach called Smoothed Particle Hydrodynamics. The theory, validation, and example applications of the 3D flooding simulation are described. Integrating these 3D simulation methods into computational risk analysis provides a spatial/visual aspect to the design, improves the realism of results, and can prove visual understanding to validate the analysis of flooding.

  19. Simulations of Coulomb systems with slab geometry using an efficient 3D Ewald summation method.

    PubMed

    dos Santos, Alexandre P; Girotto, Matheus; Levin, Yan

    2016-04-14

    We present a new approach to efficiently simulate electrolytes confined between infinite charged walls using a 3d Ewald summation method. The optimal performance is achieved by separating the electrostatic potential produced by the charged walls from the electrostatic potential of electrolyte. The electric field produced by the 3d periodic images of the walls is constant inside the simulation cell, with the field produced by the transverse images of the charged plates canceling out. The non-neutral confined electrolyte in an external potential can be simulated using 3d Ewald summation with a suitable renormalization of the electrostatic energy, to remove a divergence, and a correction that accounts for the conditional convergence of the resulting lattice sum. The new algorithm is at least an order of magnitude more rapid than the usual simulation methods for the slab geometry and can be further sped up by adopting a particle-particle particle-mesh approach.

  20. 3-D GRMHD Simulations of Disk-Jet Coupling and Emission

    NASA Technical Reports Server (NTRS)

    Nishikawa, K.-I.; Mizuno, Y.; Fuerst, S.; zei. zl/; Watson, M.; Hardee, P.; Koide, S.; Fishman, G. J.

    2006-01-01

    We have performed a fully 3-D GRMHD simulation of jet formation from a thin accretion disk around a Schwarzschild black hole with a free-falling corona. The simulation results show that a bipolar jet is initially created. At later times, the accretion disk becomes thick and the jet fades resulting in a wind that is ejected from the surface of the thickened (torus-like) disk. This evolution of disk-jet coupling suggests that the jet fades with a thickened accretion disk. Recently we have developed two new codes: 3 -D GRMHD: RelAtivIStic magnetoHydrodynamica1 sImulatioN (RAISHIN) code constructed by modern high-resolution shock-capturing (HRSC) techniques and 3-D GRPIC code. We have calculated free-free and synchrotron emission from the disks and jet/outflows obtained from our GRMHD simulations using a fully covariant radiative transfer formulation.

  1. Prototype Development Capabilities of 3D Spatial Interactions and Failures During Scenario Simulation

    SciTech Connect

    Steven Prescott; Ramprasad Sampath; Curtis Smith; Tony Koonce

    2014-09-01

    Computers have been used for 3D modeling and simulation, but only recently have computational resources been able to give realistic results in a reasonable time frame for large complex models. This report addressed the methods, techniques, and resources used to develop a prototype for using 3D modeling and simulation engine to improve risk analysis and evaluate reactor structures and components for a given scenario. The simulations done for this evaluation were focused on external events, specifically tsunami floods, for a hypothetical nuclear power facility on a coastline.

  2. Scalable Iterative Solvers Applied to 3D Parallel Simulation of Advanced Semiconductor Devices

    NASA Astrophysics Data System (ADS)

    García-Loureiro, A. J.; Aldegunde, M.; Seoane, N.

    2009-08-01

    We have studied the performance of a preconditioned iterative solver to speed up a 3D semiconductor device simulator. Since 3D simulations necessitate large computing resources, the choice of algorithms and their parameters become of utmost importance. This code uses a density gradient drift-diffusion semiconductor transport model based on the finite element method which is one of the most general and complex discretisation techniques. It has been implemented for a distributed memory multiprocessor environment using the Message Passing Interface (MPI) library. We have applied this simulator to a 67 nm effective gate length Si MOSFET.

  3. Different pressure grids for reservoir simulation in heterogeneous reservoirs

    SciTech Connect

    Guerillot, D.R.; Verdiere, S.

    1995-12-31

    Petroleum reservoirs are made of highly heterogeneous rocks. These reservoirs could be described by geostatistical models composed of millions of cells. Currently, fluid flow simulations performed within these media need upscaling (or averaging) techniques. Hence, their results are given by averaging on cells which are much larger than the geological model cells. To overcome this problem, the Dual Mesh Method is proposed here, whose purpose is to solve the pressure equation on a low resolution grid, and then to interpolate pressure over the fine mesh by taking into account small scale heterogeneities of the mediums. The aim of this paper is the interpolation step; its implementation is presented and illustrated in a five-spot pattern for three different rock characteristics.

  4. Massachusetts reservoir simulation tool—User’s manual

    USGS Publications Warehouse

    Levin, Sara B.

    2016-10-06

    IntroductionThe U.S. Geological Survey developed the Massachusetts Reservoir Simulation Tool to examine the effects of reservoirs on natural streamflows in Massachusetts by simulating the daily water balance of reservoirs. The simulation tool was developed to assist environmental managers to better manage water withdrawals in reservoirs and to preserve downstream aquatic habitats.

  5. Wavelet based Simulation of Reservoir Flow

    NASA Astrophysics Data System (ADS)

    Siddiqi, A. H.; Verma, A. K.; Noor-E-Zahra, Noor-E.-Zahra; Chandiok, Ashish; Hasan, A.

    2009-07-01

    Petroleum reservoirs consist of hydrocarbons and other chemicals trapped in the pores of a rock. The exploration and production of hydrocarbon reservoirs is still the most important technology to develop natural energy resources. Therefore, fluid flow simulators play a key role in order to help oil companies. In fact, simulation is the most important tool to model changes in a reservoir over the time. The main problem in petroleum reservoir simulation is to model the displacement of one fluid by another within a porous medium. A typical problem is characterized by the injection of a wetting fluid, for example water into the reservoir at a particular location displacing to the non wetting fluid, for example oil, which is extracted or produced at another location. Buckley-Leverett equation [1] models this process and its numerical simulation and visualization is of paramount importance. There are several numerical methods applied for numerical solution of partial differential equations modeling real world problems. We review in this paper the numerical solution of Buckley-Leverett equation for flat and non flat structures with special focus on wavelet method. We also indicate a few new avenues for further research.

  6. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N.P. Paulsson

    2005-08-21

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently hampered by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver arrays will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of

  7. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N. P. Paulsson

    2005-09-30

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently hampered by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver arrays will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of

  8. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N.P Paulsson

    2006-05-05

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently hampered by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver arrays will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of

  9. DEVELOPMENT OF A 400 LEVEL 3C CLAMPED DOWNHOLE SEISMIC RECEIVER ARRAY FOR 3D BOREHOLE SEISMIC IMAGING OF GAS RESERVOIRS

    SciTech Connect

    Bjorn N.P. Paulsson

    2004-05-01

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently frustrated by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. 3D VSP and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver array will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of the rock and the

  10. 3D simulation of tungsten low-pressure chemical vapor deposition in contact holes

    NASA Astrophysics Data System (ADS)

    Bär, E.; Lorenz, J.

    1995-10-01

    We present a new method for three-dimensional (3D) simulation of low-pressure chemical vapor deposition in arbitrary geometries using a segment-based topography discretization with triangles combined with the calculation of particle fluxes to the wafer surface. The simulation program is applied to tungsten LPCVD using the reduction of tungsten hexafluoride (WF 6) by silane (SiH 4). We found that an approach in which the redistribution of the SiH 4 molecules is simulated and a constant reaction probability after collision of a SiH 4 molecule with the surface is assumed allows the simulation of this process with a reaction probability which is consistent with thermodynamic calculations. A comparison between a simulated 3D profile and experimental data from tungsten LPCVD in a contact hole shows very good agreement between experiment and simulation.

  11. Stem dependence on stiffness in 3D RNA simulation using SimRNA

    NASA Astrophysics Data System (ADS)

    Dawson, Wayne; Boniecki, Michal; Bujnicki, Janusz

    2015-03-01

    SimRNA is a recently developed de novo 3D structure prediction program in our laboratory that uses the Monte Carlo method to search the conformation space of RNA using knowledge based energy functions. In developing the 3D model, we have also be exploring the larger physical questions about what generates differences in Kuhn length (a measure of stiffness) in biopolymers. In previoius work, this was shown to depend on the stem length and to be a function of the length and Young's modulus. A complete theoretical model was of the entropy changes due to the freezing out of degrees of freedom was developed base on this model. In this study, we find that this is further supported in the development of the 3D statitstical potentials for actual 3D simulations of RNA.

  12. 3D current source density imaging based on acoustoelectric effect: a simulation study using unipolar pulses

    PubMed Central

    Yang, Renhuan; Li, Xu; Liu, Jun; He, Bin

    2011-01-01

    It is of importance to image electrical activity and properties of biological tissues. Recently hybrid imaging modality combing ultrasound scanning and source imaging through the acousto-electric (AE) effect has generated considerable interest. Such modality has the potential to provide high spatial resolution current density imaging by utilizing the pressure induced AE resistivity change confined at the ultrasound focus. In this study, we investigate a novel 3-dimensional (3D) ultrasound current source density imaging (UCSDI) approach using unipolar ultrasound pulses. Utilizing specially designed unipolar ultrasound pulses and by combining AE signals associated to the local resistivity changes at the focusing point, we are able to reconstruct the 3D current density distribution with the boundary voltage measurements obtained while performing a 3D ultrasound scan. We have shown in computer simulation that using the present method, it is feasible to image with high spatial resolution an arbitrary 3D current density distribution in an inhomogeneous conductive media. PMID:21628774

  13. Mixed reality orthognathic surgical simulation by entity model manipulation and 3D-image display

    NASA Astrophysics Data System (ADS)

    Shimonagayoshi, Tatsunari; Aoki, Yoshimitsu; Fushima, Kenji; Kobayashi, Masaru

    2005-12-01

    In orthognathic surgery, the framing of 3D-surgical planning that considers the balance between the front and back positions and the symmetry of the jawbone, as well as the dental occlusion of teeth, is essential. In this study, a support system for orthodontic surgery to visualize the changes in the mandible and the occlusal condition and to determine the optimum position in mandibular osteotomy has been developed. By integrating the operating portion of a tooth model that is to determine the optimum occlusal position by manipulating the entity tooth model and the 3D-CT skeletal images (3D image display portion) that are simultaneously displayed in real-time, the determination of the mandibular position and posture in which the improvement of skeletal morphology and occlusal condition is considered, is possible. The realistic operation of the entity model and the virtual 3D image display enabled the construction of a surgical simulation system that involves augmented reality.

  14. 3D Printing Meets Computational Astrophysics: Deciphering the Structure of Eta Carinae’s Colliding Winds Using 3D Prints of Smoothed Particle Hydrodynamics Simulations

    NASA Astrophysics Data System (ADS)

    Madura, Thomas; Gull, Theodore R.; Clementel, Nicola; Paardekooper, Jan-Pieter; Kruip, Chael; Corcoran, Michael F.; Hamaguchi, Kenji; Teodoro, Mairan

    2015-01-01

    We present the first 3D prints of output from a supercomputer simulation of a complex astrophysical system, the colliding stellar winds in the massive (>120 MSun), highly eccentric (e ~ 0.9) binary Eta Carinae. Using a consumer-grade 3D printer (Makerbot Replicator 2X), we successfully printed 3D smoothed particle hydrodynamics simulations of Eta Carinae's inner (r ~110 AU) wind-wind collision interface at multiple orbital phases. These 3D prints reveal important, previously unknown 'finger-like' structures at orbital phases shortly after periastron (φ ~1.045) that protrude radially outward from the spiral wind-wind collision region. We speculate that these fingers are related to instabilities (e.g. Rayleigh-Taylor) that arise at the interface between the radiatively-cooled layer of dense post-shock primary-star wind and the hot, adiabatic post-shock companion-star wind. The success of our work and easy identification of previously unknown physical features highlight the important role 3D printing can play in the visualization and understanding of complex 3D time-dependent numerical simulations of astrophysical phenomena.

  15. Simulation approach of atomic layer deposition in large 3D structures

    NASA Astrophysics Data System (ADS)

    Schwille, Matthias C.; Barth, Jonas; Schössler, Timo; Schön, Florian; Bartha, Johann W.; Oettel, Martin

    2017-04-01

    We present a new simulation method predicting thicknesses of thin films obtained by atomic layer deposition in high aspect ratio 3D geometries as they appear in MEMS manufacturing. The method features a Monte-Carlo computation of film deposition in free molecular flow, as well as in the Knudsen and diffusive gas regime, applicable for large structures. We compare our approach to analytic and simulation results from the literature. The capability of the method is demonstrated by a comparison to experimental film thicknesses in a large 3D structure. Finally, the feasability to extract process parameters, i.e. sticking coefficients is shown.

  16. Ground motion simulations in Marmara (Turkey) region from 3D finite difference method

    NASA Astrophysics Data System (ADS)

    Aochi, Hideo; Ulrich, Thomas; Douglas, John

    2016-04-01

    In the framework of the European project MARSite (2012-2016), one of the main contributions from our research team was to provide ground-motion simulations for the Marmara region from various earthquake source scenarios. We adopted a 3D finite difference code, taking into account the 3D structure around the Sea of Marmara (including the bathymetry) and the sea layer. We simulated two moderate earthquakes (about Mw4.5) and found that the 3D structure improves significantly the waveforms compared to the 1D layer model. Simulations were carried out for different earthquakes (moderate point sources and large finite sources) in order to provide shake maps (Aochi and Ulrich, BSSA, 2015), to study the variability of ground-motion parameters (Douglas & Aochi, BSSA, 2016) as well as to provide synthetic seismograms for the blind inversion tests (Diao et al., GJI, 2016). The results are also planned to be integrated in broadband ground-motion simulations, tsunamis generation and simulations of triggered landslides (in progress by different partners). The simulations are freely shared among the partners via the internet and the visualization of the results is diffused on the project's homepage. All these simulations should be seen as a reference for this region, as they are based on the latest knowledge that obtained during the MARSite project, although their refinement and validation of the model parameters and the simulations are a continuing research task relying on continuing observations. The numerical code used, the models and the simulations are available on demand.

  17. 2D-3D hybrid stabilized finite element method for tsunami runup simulations

    NASA Astrophysics Data System (ADS)

    Takase, S.; Moriguchi, S.; Terada, K.; Kato, J.; Kyoya, T.; Kashiyama, K.; Kotani, T.

    2016-09-01

    This paper presents a two-dimensional (2D)-three-dimensional (3D) hybrid stabilized finite element method that enables us to predict a propagation process of tsunami generated in a hypocentral region, which ranges from offshore propagation to runup to urban areas, with high accuracy and relatively low computational costs. To be more specific, the 2D shallow water equation is employed to simulate the propagation of offshore waves, while the 3D Navier-Stokes equation is employed for the runup in urban areas. The stabilized finite element method is utilized for numerical simulations for both of the 2D and 3D domains that are independently discretized with unstructured meshes. The multi-point constraint and transmission methods are applied to satisfy the continuity of flow velocities and pressures at the interface between the resulting 2D and 3D meshes, since neither their spatial dimensions nor node arrangements are consistent. Numerical examples are presented to demonstrate the performance of the proposed hybrid method to simulate tsunami behavior, including offshore propagation and runup to urban areas, with substantially lower computation costs in comparison with full 3D computations.

  18. Simulation-Guided 3D Nanomanufacturing via Focused Electron Beam Induced Deposition

    SciTech Connect

    Fowlkes, Jason D.; Winkler, Robert; Lewis, Brett B.; Stanford, Michael G.; Plank, Harald; Rack, Philip D.

    2016-06-10

    Focused electron beam induced deposition (FEBID) is one of the few techniques that enables direct-write synthesis of free-standing 3D nanostructures. While the fabrication of simple architectures such as vertical or curving nanowires has been achieved by simple trial and error, processing complex 3D structures is not tractable with this approach. This is due, inpart, to the dynamic interplay between electron–solid interactions and the transient spatial distribution of absorbed precursor molecules on the solid surface. Here, we demonstrate the ability to controllably deposit 3D lattice structures at the micro/nanoscale, which have received recent interest owing to superior mechanical and optical properties. Moreover, a hybrid Monte Carlo–continuum simulation is briefly overviewed, and subsequently FEBID experiments and simulations are directly compared. Finally, a 3D computer-aided design (CAD) program is introduced, which generates the beam parameters necessary for FEBID by both simulation and experiment. In using this approach, we demonstrate the fabrication of various 3D lattice structures using Pt-, Au-, and W-based precursors.

  19. Simulation-Guided 3D Nanomanufacturing via Focused Electron Beam Induced Deposition

    DOE PAGES

    Fowlkes, Jason D.; Winkler, Robert; Lewis, Brett B.; ...

    2016-06-10

    Focused electron beam induced deposition (FEBID) is one of the few techniques that enables direct-write synthesis of free-standing 3D nanostructures. While the fabrication of simple architectures such as vertical or curving nanowires has been achieved by simple trial and error, processing complex 3D structures is not tractable with this approach. This is due, inpart, to the dynamic interplay between electron–solid interactions and the transient spatial distribution of absorbed precursor molecules on the solid surface. Here, we demonstrate the ability to controllably deposit 3D lattice structures at the micro/nanoscale, which have received recent interest owing to superior mechanical and optical properties.more » Moreover, a hybrid Monte Carlo–continuum simulation is briefly overviewed, and subsequently FEBID experiments and simulations are directly compared. Finally, a 3D computer-aided design (CAD) program is introduced, which generates the beam parameters necessary for FEBID by both simulation and experiment. In using this approach, we demonstrate the fabrication of various 3D lattice structures using Pt-, Au-, and W-based precursors.« less

  20. Accurate load prediction by BEM with airfoil data from 3D RANS simulations

    NASA Astrophysics Data System (ADS)

    Schneider, Marc S.; Nitzsche, Jens; Hennings, Holger

    2016-09-01

    In this paper, two methods for the extraction of airfoil coefficients from 3D CFD simulations of a wind turbine rotor are investigated, and these coefficients are used to improve the load prediction of a BEM code. The coefficients are extracted from a number of steady RANS simulations, using either averaging of velocities in annular sections, or an inverse BEM approach for determination of the induction factors in the rotor plane. It is shown that these 3D rotor polars are able to capture the rotational augmentation at the inner part of the blade as well as the load reduction by 3D effects close to the blade tip. They are used as input to a simple BEM code and the results of this BEM with 3D rotor polars are compared to the predictions of BEM with 2D airfoil coefficients plus common empirical corrections for stall delay and tip loss. While BEM with 2D airfoil coefficients produces a very different radial distribution of loads than the RANS simulation, the BEM with 3D rotor polars manages to reproduce the loads from RANS very accurately for a variety of load cases, as long as the blade pitch angle is not too different from the cases from which the polars were extracted.

  1. 3D simulations of fluctuation spectra in the hall-MHD plasma.

    PubMed

    Shaikh, Dastgeer; Shukla, P K

    2009-01-30

    Turbulent spectral cascades are investigated by means of fully three-dimensional (3D) simulations of a compressible Hall-magnetohydrodynamic (H-MHD) plasma in order to understand the observed spectral break in the solar wind turbulence spectra in the regime where the characteristic length scales associated with electromagnetic fluctuations are smaller than the ion gyroradius. In this regime, the results of our 3D simulations exhibit that turbulent spectral cascades in the presence of a mean magnetic field follow an omnidirectional anisotropic inertial-range spectrum close to k(-7/3). The latter is associated with the Hall current arising from nonequal electron and ion fluid velocities in our 3D H-MHD plasma model.

  2. 3-D FDTD simulation of shear waves for evaluation of complex modulus imaging.

    PubMed

    Orescanin, Marko; Wang, Yue; Insana, Michael

    2011-02-01

    The Navier equation describing shear wave propagation in 3-D viscoelastic media is solved numerically with a finite differences time domain (FDTD) method. Solutions are formed in terms of transverse scatterer velocity waves and then verified via comparison to measured wave fields in heterogeneous hydrogel phantoms. The numerical algorithm is used as a tool to study the effects on complex shear modulus estimation from wave propagation in heterogeneous viscoelastic media. We used an algebraic Helmholtz inversion (AHI) technique to solve for the complex shear modulus from simulated and experimental velocity data acquired in 2-D and 3-D. Although 3-D velocity estimates are required in general, there are object geometries for which 2-D inversions provide accurate estimations of the material properties. Through simulations and experiments, we explored artifacts generated in elastic and dynamic-viscous shear modulus images related to the shear wavelength and average viscosity.

  3. Stochastic microstructure modeling and electrochemical simulation of lithium-ion cell anodes in 3D

    NASA Astrophysics Data System (ADS)

    Hein, Simon; Feinauer, Julian; Westhoff, Daniel; Manke, Ingo; Schmidt, Volker; Latz, Arnulf

    2016-12-01

    Thermodynamically consistent transport theory is used to compare 3D images of real anode microstructures from lithium-ion batteries to virtual ones created by a parametric stochastic 3D microstructure model. Half-cell simulations in 3D with spatially resolved microstructures at different applied currents show that for low currents the deviations between various electrochemical quantities like current density or overpotential are negligibly small. For larger currents small differences become more pronounced. Qualitative and quantitative differences of these features are discussed with respect to the microstructure and it is shown that the real and virtual structures behave similar during electrochemical simulations. Extensions of the stochastic microstructure model, which overcome small differences in electrochemical behavior, are proposed.

  4. 3D numerical simulation analysis of passive drag near free surface in swimming

    NASA Astrophysics Data System (ADS)

    Zhan, Jie-min; Li, Tian-zeng; Chen, Xue-bin; Li, Yok-sheung; Wai, Wing-hong Onyx

    2015-04-01

    The aim of this work is to build a 3D numerical model to study the characteristics of passive drag on competitive swimmers taking into account the impact of the free surface. This model solves the 3D incompressible Navier-Stokes equations using RNG k- ɛ turbulence closure. The volume of fluid (VOF) method is used to locate the free surface. The 3D virtual model is created by Computer Aided Industrial Design (CAID) software, Rhinoceros. Firstly, a specific posture of swimming is studied. The simulation results are in good agreement with the data from mannequin towing experiments. The effects of a swimmer's arms and legs positions on swimming performance are then studied. Finally, it is demonstrated that the present method is capable of simulating gliding near the free surface.

  5. Numerical simulations and vorticity dynamics of self-propelled swimming of 3D bionic fish

    NASA Astrophysics Data System (ADS)

    Xin, ZhiQiang; Wu, ChuiJie

    2012-02-01

    Numerical simulations and the control of self-propelled swimming of three-dimensional bionic fish in a viscous flow and the mechanism of fish swimming are carried out in this study, with a 3D computational fluid dynamics package, which includes the immersed boundary method and the volume of fluid method, the adaptive multi-grid finite volume method, and the control strategy of fish swimming. Firstly, the mechanism of 3D fish swimming was studied and the vorticity dynamics root was traced to the moving body surface by using the boundary vorticity-flux theory. With the change of swimming speed, the contributions of the fish body and caudal fin to thrust are analyzed quantitatively. The relationship between vortex structures of fish swimming and the forces exerted on the fish body are also given in this paper. Finally, the 3D wake structure of self-propelled swimming of 3D bionic fish is presented. The in-depth analysis of the 3D vortex structure in the role of 3D biomimetic fish swimming is also performed.

  6. Peach Bottom 2 Turbine Trip Simulation Using TRAC-BF1/COS3D, a Best-Estimate Coupled 3-D Core and Thermal-Hydraulic Code System

    SciTech Connect

    Ui, Atsushi; Miyaji, Takamasa

    2004-10-15

    The best-estimate coupled three-dimensional (3-D) core and thermal-hydraulic code system TRAC-BF1/COS3D has been developed. COS3D, based on a modified one-group neutronic model, is a 3-D core simulator used for licensing analyses and core management of commercial boiling water reactor (BWR) plants in Japan. TRAC-BF1 is a plant simulator based on a two-fluid model. TRAC-BF1/COS3D is a coupled system of both codes, which are connected using a parallel computing tool. This code system was applied to the OECD/NRC BWR Turbine Trip Benchmark. Since the two-group cross-section tables are provided by the benchmark team, COS3D was modified to apply to this specification. Three best-estimate scenarios and four hypothetical scenarios were calculated using this code system. In the best-estimate scenario, the predicted core power with TRAC-BF1/COS3D is slightly underestimated compared with the measured data. The reason seems to be a slight difference in the core boundary conditions, that is, pressure changes and the core inlet flow distribution, because the peak in this analysis is sensitive to them. However, the results of this benchmark analysis show that TRAC-BF1/COS3D gives good precision for the prediction of the actual BWR transient behavior on the whole. Furthermore, the results with the modified one-group model and the two-group model were compared to verify the application of the modified one-group model to this benchmark. This comparison shows that the results of the modified one-group model are appropriate and sufficiently precise.

  7. [Pre-surgical simulation of microvascular decompression for hemifacial spasm using 3D-models].

    PubMed

    Mashiko, Toshihiro; Yang, Qiang; Kaneko, Naoki; Konno, Takehiko; Yamaguchi, Takashi; Watanabe, Eiju

    2015-01-01

    We have been performing pre-surgical simulations using custom-built patient-specific 3D-models. Here we report the advantageous use of 3D-models for simulating microvascular decompression(MVD)for hemifacial spasms. Seven cases of MVD surgery were performed. Two types of 3D-printers were used to fabricate the 3D-models:one using plaster as the modeling material(Z Printer®450, 3D systems, Rock Hill, SC, USA)and the other using acrylonitrile butadiene styrene(ABS)(UP! Plus 3D printer®, Beijing Tiertime Technology, Beijing). We tested three types of models. Type 1 was a plaster model of the brainstem, cerebellum, facial nerve, and the artery compressing the root exit zone of the facial nerve. Part of the cerebellum was digitally trimmed off to observe "the compressing point" from the same angle as that used during actual surgery. Type 2 was a modified Type 1 in which part of the skull was opened digitally to mimic a craniectomy. Type 3 was a combined model in which the cerebellum and the artery of the Type 2 model were replaced by a soft retractable cerebellum and an elastic artery. The cerebellum was made from polyurethane and cast from a plaster prototype. To fabricate elastic arteries, liquid silicone was painted onto the surface of an ABS artery and the inner ABS model was dissolved away using solvent. In all cases, the 3D-models were very useful. Although each type has advantages, the Type-3 model was judged extremely useful for training junior surgeons in microsurgical approaches.

  8. Qualitative Assessment of a 3D Simulation Program: Faculty, Students, and Bio-Organic Reaction Animations

    ERIC Educational Resources Information Center

    Günersel, Adalet B.; Fleming, Steven A.

    2013-01-01

    Research shows that computer-based simulations and animations are especially helpful in fields such as chemistry where concepts are abstract and cannot be directly observed. Bio-Organic Reaction Animations (BioORA) is a freely available 3D visualization software program developed to help students understand the chemistry of biomolecular events.…

  9. Learning Patterns as Criterion for Forming Work Groups in 3D Simulation Learning Environments

    ERIC Educational Resources Information Center

    Maria Cela-Ranilla, Jose; Molías, Luis Marqués; Cervera, Mercè Gisbert

    2016-01-01

    This study analyzes the relationship between the use of learning patterns as a grouping criterion to develop learning activities in the 3D simulation environment at University. Participants included 72 Spanish students from the Education and Marketing disciplines. Descriptive statistics and non-parametric tests were conducted. The process was…

  10. Online Stereo 3D Simulation in Studying the Spherical Pendulum in Conservative Force Field

    ERIC Educational Resources Information Center

    Zabunov, Svetoslav S.

    2013-01-01

    The current paper aims at presenting a modern e-learning method and tool that is utilized in teaching physics in the universities. An online stereo 3D simulation is used for e-learning mechanics and specifically the teaching of spherical pendulum as part of the General Physics course for students in the universities. This approach was realized on…

  11. Structured light imaging system for structural and optical characterization of 3D tissue-simulating phantoms

    NASA Astrophysics Data System (ADS)

    Liu, Songde; Smith, Zach; Xu, Ronald X.

    2016-10-01

    There is a pressing need for a phantom standard to calibrate medical optical devices. However, 3D printing of tissue-simulating phantom standard is challenged by lacking of appropriate methods to characterize and reproduce surface topography and optical properties accurately. We have developed a structured light imaging system to characterize surface topography and optical properties (absorption coefficient and reduced scattering coefficient) of 3D tissue-simulating phantoms. The system consisted of a hyperspectral light source, a digital light projector (DLP), a CMOS camera, two polarizers, a rotational stage, a translation stage, a motion controller, and a personal computer. Tissue-simulating phantoms with different structural and optical properties were characterized by the proposed imaging system and validated by a standard integrating sphere system. The experimental results showed that the proposed system was able to achieve pixel-level optical properties with a percentage error of less than 11% for absorption coefficient and less than 7% for reduced scattering coefficient for phantoms without surface curvature. In the meanwhile, 3D topographic profile of the phantom can be effectively reconstructed with an accuracy of less than 1% deviation error. Our study demonstrated that the proposed structured light imaging system has the potential to characterize structural profile and optical properties of 3D tissue-simulating phantoms.

  12. PEGASUS. 3D Direct Simulation Monte Carlo Code Which Solves for Geometrics

    SciTech Connect

    Bartel, T.J.

    1998-12-01

    Pegasus is a 3D Direct Simulation Monte Carlo Code which solves for geometries which can be represented by bodies of revolution. Included are all the surface chemistry enhancements in the 2D code Icarus as well as a real vacuum pump model. The code includes multiple species transport.

  13. 3D Direct Simulation Monte Carlo Code Which Solves for Geometrics

    SciTech Connect

    Bartel, Timothy J.

    1998-01-13

    Pegasus is a 3D Direct Simulation Monte Carlo Code which solves for geometries which can be represented by bodies of revolution. Included are all the surface chemistry enhancements in the 2D code Icarus as well as a real vacuum pump model. The code includes multiple species transport.

  14. Results of a 3-D full particle simulation of quasi-perpendicular shock

    NASA Astrophysics Data System (ADS)

    Shinohara, I.; Fujimoto, M.

    2010-12-01

    Recent progress of computational power enables us to perform really macro-scale three-dimensional situations with full particle codes. In this presentation, we will report results of a three-dimensional simulation of a quasi-perpendicular shock. The simulation parameters were selected to simulate a Cluster-II observational result reported by Seki et al. (2009), M_A=7.4 and beta=0.16. The realistic mass ratio mi/me=1840 was taken, and almost one ion inertia length square could be allocated to the plane perpendicular to the upstream flow axis. The result shows that both the self-reformation process and whistler emission are observed. However, the 3-D result is not a simple superposition of 2-D results. The most impressive feature is that quite complicated wave activity is found in the shock foot region. With the help of this wave activity, electron heating observed in the 3-D run is more efficient than those in the 1-D and 2-D runs with the same shock parameters. Moreover, non-thermal electrons are also produced only in the 3D run. In this paper, comparing the 3-D result with previous 1-D and 2-D simulation results, three dimensional nature of the shock transition region of quasi-perpendicular shock is discussed.

  15. 3D simulation of silicon micro-ring resonator with Comsol

    NASA Astrophysics Data System (ADS)

    Degtyarev, S. A.; Podlipnov, V. V.; Verma, Payal; Khonina, S. N.

    2016-12-01

    In this paper we provide 3d full-vector static electromagnetic simulation of silicon micro-ring resonator operating. We show that geometrical and scalar approaches are not sufficiently accurate for calculating resonator parameters. Quite strong dependence of ring resonator radius on waveguide width is revealed.

  16. An object-oriented simulator for 3D digital breast tomosynthesis imaging system.

    PubMed

    Seyyedi, Saeed; Cengiz, Kubra; Kamasak, Mustafa; Yildirim, Isa

    2013-01-01

    Digital breast tomosynthesis (DBT) is an innovative imaging modality that provides 3D reconstructed images of breast to detect the breast cancer. Projections obtained with an X-ray source moving in a limited angle interval are used to reconstruct 3D image of breast. Several reconstruction algorithms are available for DBT imaging. Filtered back projection algorithm has traditionally been used to reconstruct images from projections. Iterative reconstruction algorithms such as algebraic reconstruction technique (ART) were later developed. Recently, compressed sensing based methods have been proposed in tomosynthesis imaging problem. We have developed an object-oriented simulator for 3D digital breast tomosynthesis (DBT) imaging system using C++ programming language. The simulator is capable of implementing different iterative and compressed sensing based reconstruction methods on 3D digital tomosynthesis data sets and phantom models. A user friendly graphical user interface (GUI) helps users to select and run the desired methods on the designed phantom models or real data sets. The simulator has been tested on a phantom study that simulates breast tomosynthesis imaging problem. Results obtained with various methods including algebraic reconstruction technique (ART) and total variation regularized reconstruction techniques (ART+TV) are presented. Reconstruction results of the methods are compared both visually and quantitatively by evaluating performances of the methods using mean structural similarity (MSSIM) values.

  17. Multi-scale simulations of space problems with iPIC3D

    NASA Astrophysics Data System (ADS)

    Lapenta, Giovanni; Bettarini, Lapo; Markidis, Stefano

    The implicit Particle-in-Cell method for the computer simulation of space plasma, and its im-plementation in a three-dimensional parallel code, called iPIC3D, are presented. The implicit integration in time of the Vlasov-Maxwell system removes the numerical stability constraints and enables kinetic plasma simulations at magnetohydrodynamics scales. Simulations of mag-netic reconnection in plasma are presented to show the effectiveness of the algorithm. In particular we will show a number of simulations done for large scale 3D systems using the physical mass ratio for Hydrogen. Most notably one simulation treats kinetically a box of tens of Earth radii in each direction and was conducted using about 16000 processors of the Pleiades NASA computer. The work is conducted in collaboration with the MMS-IDS theory team from University of Colorado (M. Goldman, D. Newman and L. Andersson). Reference: Stefano Markidis, Giovanni Lapenta, Rizwan-uddin Multi-scale simulations of plasma with iPIC3D Mathematics and Computers in Simulation, Available online 17 October 2009, http://dx.doi.org/10.1016/j.matcom.2009.08.038

  18. 3D Radiative Transfer in Eta Carinae: Application of the SimpleX Algorithm to 3D SPH Simulations of Binary Colliding Winds

    NASA Technical Reports Server (NTRS)

    Clementel, N.; Madura, T. I.; Kruip, C.J.H.; Icke, V.; Gull, T. R.

    2014-01-01

    Eta Carinae is an ideal astrophysical laboratory for studying massive binary interactions and evolution, and stellar wind-wind collisions. Recent three-dimensional (3D) simulations set the stage for understanding the highly complex 3D flows in eta Car. Observations of different broad high- and low-ionization forbidden emission lines provide an excellent tool to constrain the orientation of the system, the primary's mass-loss rate, and the ionizing flux of the hot secondary. In this work we present the first steps towards generating synthetic observations to compare with available and future HST/STIS data. We present initial results from full 3D radiative transfer simulations of the interacting winds in eta Car.We use the SimpleX algorithm to post-process the output from 3D SPH simulations and obtain the ionization fractions of hydrogen and helium assuming three different mass-loss rates for the primary star. The resultant ionization maps of both species constrain the regions where the observed forbidden emission lines can form. Including collisional ionization is necessary to achieve a better description of the ionization states, especially in the areas shielded from the secondary's radiation. We find that reducing the primary's mass-loss rate increases the volume of ionized gas, creating larger areas where the forbidden emission lines can form.We conclude that post processing 3D SPH data with SimpleX is a viable tool to create ionization maps for eta Car.

  19. 3D Radiative Transfer in Eta Carinae: Application of the SimpleX Algorithm to 3D SPH Simulations of Binary Colliding Winds

    NASA Technical Reports Server (NTRS)

    Clementel, N.; Madura, T. I.; Kruip, C. J. H.; Icke, V.; Gull, T. R.

    2014-01-01

    Eta Carinae is an ideal astrophysical laboratory for studying massive binary interactions and evolution, and stellar wind-wind collisions. Recent three-dimensional (3D) simulations set the stage for understanding the highly complex 3D flows in Eta Car. Observations of different broad high- and low-ionization forbidden emission lines provide an excellent tool to constrain the orientation of the system, the primary's mass-loss rate, and the ionizing flux of the hot secondary. In this work we present the first steps towards generating synthetic observations to compare with available and future HST/STIS data. We present initial results from full 3D radiative transfer simulations of the interacting winds in Eta Car. We use the SimpleX algorithm to post-process the output from 3D SPH simulations and obtain the ionization fractions of hydrogen and helium assuming three different mass-loss rates for the primary star. The resultant ionization maps of both species constrain the regions where the observed forbidden emission lines can form. Including collisional ionization is necessary to achieve a better description of the ionization states, especially in the areas shielded from the secondary's radiation. We find that reducing the primary's mass-loss rate increases the volume of ionized gas, creating larger areas where the forbidden emission lines can form. We conclude that post processing 3D SPH data with SimpleX is a viable tool to create ionization maps for Eta Car.

  20. The Vajont disaster: a 3D numerical simulation for the slide and the waves

    NASA Astrophysics Data System (ADS)

    Rubino, Angelo; Androsov, Alexey; Vacondio, Renato; Zanchettin, Davide; Voltzinger, Naum

    2016-04-01

    A very high resolution O(5 m), 3D hydrostatic nonlinear numerical model was used to simulate the dynamics of both the slide and the surface waves produced during the Vajont disaster (north Italy, 1963), one of the major landslide-induced tsunamis ever documented. Different simulated wave phenomena like, e.g., maximum run-up on the opposite shore, maximum height, and water velocity were analyzed and compared with data available in literature, including the results of a fully 3D simulation obtained with a Smoothed Particle Hydrodynamic code. The difference between measured and simulated after-slide bathymetries was calculated and used in an attempt to quantify the relative magnitude and extension of rigid and fluid motion components during the event.

  1. The computer simulation of 3d gas dynamics in a gas centrifuge

    NASA Astrophysics Data System (ADS)

    Borman, V. D.; Bogovalov, S. V.; Borisevich, V. D.; Tronin, I. V.; Tronin, V. N.

    2016-09-01

    We argue on the basis of the results of 2D analysis of the gas flow in gas centrifuges that a reliable calculation of the circulation of the gas and gas content in the gas centrifuge is possible only in frameworks of 3D numerical simulation of gas dynamics in the gas centrifuge (hereafter GC). The group from National research nuclear university, MEPhI, has created a computer code for 3D simulation of the gas flow in GC. The results of the computer simulations of the gas flows in GC are presented. A model Iguassu centrifuge is explored for the simulations. A nonaxisymmetric gas flow is produced due to interaction of the hypersonic rotating flow with the scoops for extraction of the product and waste flows from the GC. The scoops produce shock waves penetrating into a working camera of the GC and form spiral waves there.

  2. GPU accelerated simulations of 3D deterministic particle transport using discrete ordinates method

    SciTech Connect

    Gong Chunye; Liu Jie; Chi Lihua; Huang Haowei; Fang Jingyue; Gong Zhenghu

    2011-07-01

    Graphics Processing Unit (GPU), originally developed for real-time, high-definition 3D graphics in computer games, now provides great faculty in solving scientific applications. The basis of particle transport simulation is the time-dependent, multi-group, inhomogeneous Boltzmann transport equation. The numerical solution to the Boltzmann equation involves the discrete ordinates (S{sub n}) method and the procedure of source iteration. In this paper, we present a GPU accelerated simulation of one energy group time-independent deterministic discrete ordinates particle transport in 3D Cartesian geometry (Sweep3D). The performance of the GPU simulations are reported with the simulations of vacuum boundary condition. The discussion of the relative advantages and disadvantages of the GPU implementation, the simulation on multi GPUs, the programming effort and code portability are also reported. The results show that the overall performance speedup of one NVIDIA Tesla M2050 GPU ranges from 2.56 compared with one Intel Xeon X5670 chip to 8.14 compared with one Intel Core Q6600 chip for no flux fixup. The simulation with flux fixup on one M2050 is 1.23 times faster than on one X5670.

  3. Evolution of analyzing reservoir simulation data

    SciTech Connect

    Phelps, R.E.; Huang, A.Y.

    1994-12-31

    Numerical Reservoir Simulation is routinely used by the petroleum producing companies world-wide as an engineering tool to efficiently manage their hydrocarbon reservoirs. The task of building models with a large number of grid-blocks is not easy, and to analyze the voluminous results produced by such models is even more difficult. This paper discusses the historical evolution of techniques used to analyze reservoir simulation data over the past decade. It outlines how the advancement of workstation technology and the introduction of X-Window System opened up an entirely new way of utilizing mainframe computing power and workstation graphical display capabilities, simultaneously. The paper also discusses Saudi Aramco`s experience in the development of sophisticated reservoir simulation post-processing packages. The need for direct communication between the programmer and end-users to facilitate a user-friendly package is emphasized. A practical example illustrating the benefit of these post-processing packages in the construction and history matching of a large model with approximately 52,000 cells is presented. Savings in manpower and computer resources using current technology are estimated.

  4. Evolution of analyzing reservoir simulation data

    SciTech Connect

    Phelps, R.E.; Huang, A.Y.

    1995-12-01

    Petroleum-producing companies world-wide routinely use numerical reservoir simulation as an engineering tool to manage their hydrocarbon reservoirs efficiently. The task of building models with a large number of gridblocks is not easy, and analyzing the voluminous results produced by such models is even more difficult. This paper discusses the historical evolution of techniques used to analyze reservoir simulation data over the past decade. It outlines how the advancement of workstation technology and the introduction of an X-Window system opened up an entirely new way of using mainframe computing power and workstation graphical display capabilities simultaneously. The paper also discusses Saudi Aramco`s experience in the development of sophisticated reservoir simulation postprocessing packages. The authors emphasize the need for direct communication between the programmer and end users to facilitate a user-friendly package. They present a practical example illustrating the benefit of these postprocessing packages in the construction and history matching of a large model with approximately 52,000 cells. They estimate savings in manpower and computer resources using current technology.

  5. The program FANS-3D (finite analytic numerical simulation 3-dimensional) and its applications

    NASA Technical Reports Server (NTRS)

    Bravo, Ramiro H.; Chen, Ching-Jen

    1992-01-01

    In this study, the program named FANS-3D (Finite Analytic Numerical Simulation-3 Dimensional) is presented. FANS-3D was designed to solve problems of incompressible fluid flow and combined modes of heat transfer. It solves problems with conduction and convection modes of heat transfer in laminar flow, with provisions for radiation and turbulent flows. It can solve singular or conjugate modes of heat transfer. It also solves problems in natural convection, using the Boussinesq approximation. FANS-3D was designed to solve heat transfer problems inside one, two and three dimensional geometries that can be represented by orthogonal planes in a Cartesian coordinate system. It can solve internal and external flows using appropriate boundary conditions such as symmetric, periodic and user specified.

  6. 3D dynamic simulation of crack propagation in extracorporeal shock wave lithotripsy

    NASA Astrophysics Data System (ADS)

    Wijerathne, M. L. L.; Hori, Muneo; Sakaguchi, Hide; Oguni, Kenji

    2010-06-01

    Some experimental observations of Shock Wave Lithotripsy(SWL), which include 3D dynamic crack propagation, are simulated with the aim of reproducing fragmentation of kidney stones with SWL. Extracorporeal shock wave lithotripsy (ESWL) is the fragmentation of kidney stones by focusing an ultrasonic pressure pulse onto the stones. 3D models with fine discretization are used to accurately capture the high amplitude shear shock waves. For solving the resulting large scale dynamic crack propagation problem, PDS-FEM is used; it provides numerically efficient failure treatments. With a distributed memory parallel code of PDS-FEM, experimentally observed 3D photoelastic images of transient stress waves and crack patterns in cylindrical samples are successfully reproduced. The numerical crack patterns are in good agreement with the experimental ones, quantitatively. The results shows that the high amplitude shear waves induced in solid, by the lithotriptor generated shock wave, play a dominant role in stone fragmentation.

  7. Simulations of 3D-Si sensors for the innermost layer of the ATLAS pixel upgrade

    NASA Astrophysics Data System (ADS)

    Baselga, M.; Pellegrini, G.; Quirion, D.

    2017-03-01

    The LHC is expected to reach luminosities up to 3000 fb-1 and the innermost layer of the ATLAS upgrade plans to cope with higher occupancy and to decrease the pixel size. 3D-Si sensors are a good candidate for the innermost layer of the ATLAS pixel upgrade since they exhibit good performance under high fluences and the new designs will have smaller pixel size to fulfill the electronics expectations. This paper reports TCAD simulations of the 3D-Si sensors designed at IMB-CNM with non-passing-through columns that are being fabricated for the next innermost layer of the ATLAS pixel upgrade. It shows the charge collection response before and after irradiation, and the response of 3D-Si sensors located at large η angles.

  8. Parallel implementation of 3D FFT with volumetric decomposition schemes for efficient molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Jung, Jaewoon; Kobayashi, Chigusa; Imamura, Toshiyuki; Sugita, Yuji

    2016-03-01

    Three-dimensional Fast Fourier Transform (3D FFT) plays an important role in a wide variety of computer simulations and data analyses, including molecular dynamics (MD) simulations. In this study, we develop hybrid (MPI+OpenMP) parallelization schemes of 3D FFT based on two new volumetric decompositions, mainly for the particle mesh Ewald (PME) calculation in MD simulations. In one scheme, (1d_Alltoall), five all-to-all communications in one dimension are carried out, and in the other, (2d_Alltoall), one two-dimensional all-to-all communication is combined with two all-to-all communications in one dimension. 2d_Alltoall is similar to the conventional volumetric decomposition scheme. We performed benchmark tests of 3D FFT for the systems with different grid sizes using a large number of processors on the K computer in RIKEN AICS. The two schemes show comparable performances, and are better than existing 3D FFTs. The performances of 1d_Alltoall and 2d_Alltoall depend on the supercomputer network system and number of processors in each dimension. There is enough leeway for users to optimize performance for their conditions. In the PME method, short-range real-space interactions as well as long-range reciprocal-space interactions are calculated. Our volumetric decomposition schemes are particularly useful when used in conjunction with the recently developed midpoint cell method for short-range interactions, due to the same decompositions of real and reciprocal spaces. The 1d_Alltoall scheme of 3D FFT takes 4.7 ms to simulate one MD cycle for a virus system containing more than 1 million atoms using 32,768 cores on the K computer.

  9. Magnetic Dissipation in Asymmetric Strong Guide 3D Simulations: Examples of Magnetic Diffusion and Reconnection

    NASA Astrophysics Data System (ADS)

    Scudder, J. D.; Karimabadi, H.; Daughton, W. S.

    2013-12-01

    Interpretations of 2D simulations of magnetic reconnection are greatly simplified by using the flux function, usually the out of plane component of the vector potential. This theoretical device is no longer available when simulations are analyzed in 3-D. We illustrate the results of determining the locale rates of flux slippage in simulations by a technique based on Maxwell's equations. The technique recovers the usual results obtained for the flux function in 2D simulations, but remains viable in 3D simulations where there is no flux function. The method has also been successfully tested for full PIC simulations where reconnection is geometrically forbiddden. While such layers possess measurable flux slippages (diffusion) their level is not as strong as recorded in known 2D PIC reconnection sites using the same methodology. This approach will be used to explore the spatial incidence and strength of flux slippages across a 3D, asymmetric, strong guide field run discussed previously in the literature. Regions of diffusive behavior are illustrated where LHDI has been previously identified out on the separatrices, while much stronger flux slippages, typical of the X-regions of 2D simulations, are shown to occur elsewhere throughout the simulation. These results suggest that reconnection requires sufficiently vigorous flux slippage to be self sustaining, while non-zero flux slippage can and does occur without being at the reconnection site. A cross check of this approach is provided by the mixing ratio of tagged simulation particles of known spatial origin discussed by Daughton et al., 2013 (this meeting); they provide an integral measure of flux slippage up to the present point in the simulation. We will discuss the correlations between our Maxwell based flux slippage rates and the inferred rates of change of this mixing ratio (as recorded in the local fluid frame).

  10. Simulation of bootstrap current in 2D and 3D ideal magnetic fields in tokamaks

    NASA Astrophysics Data System (ADS)

    Raghunathan, M.; Graves, J. P.; Cooper, W. A.; Pedro, M.; Sauter, O.

    2016-09-01

    We aim to simulate the bootstrap current for a MAST-like spherical tokamak using two approaches for magnetic equilibria including externally caused 3D effects such as resonant magnetic perturbations (RMPs), the effect of toroidal ripple, and intrinsic 3D effects such as non-resonant internal kink modes. The first approach relies on known neoclassical coefficients in ideal MHD equilibria, using the Sauter (Sauter et al 1999 Phys. Plasmas 6 2834) expression valid for all collisionalities in axisymmetry, and the second approach being the quasi-analytic Shaing-Callen (Shaing and Callen 1983 Phys. Fluids 26 3315) model in the collisionless regime for 3D. Using the ideal free-boundary magnetohydrodynamic code VMEC, we compute the flux-surface averaged bootstrap current density, with the Sauter and Shaing-Callen expressions for 2D and 3D ideal MHD equilibria including an edge pressure barrier with the application of resonant magnetic perturbations, and equilibria possessing a saturated non-resonant 1/1 internal kink mode with a weak internal pressure barrier. We compare the applicability of the self-consistent iterative model on the 3D applications and discuss the limitations and advantages of each bootstrap current model for each type of equilibrium.

  11. 3-D land subsidence simulation using the NDIS package for MODFLOW

    NASA Astrophysics Data System (ADS)

    Kang, D. H.; Li, J.

    2015-11-01

    The standard subsidence package for MODFLOW, MODFLOW-SUB simulates aquifer-system compaction and subsidence assuming that only 1-D-vertical displacement of the aquifer system occurs in response to applied stresses such as drawdowns accompanying groundwater extraction. In the present paper, 3-D movement of an aquifer system in responses to one or more pumping wells is considered using the new aquifer-system deformation package for MODFLOW, NDIS. The simulation of aquifer- system 3-D movement using NDIS was conducted with a stress or hydraulic head dependent specific storage coefficient to simulate nonlinear deformation behavior of aquifer-system sedimentary materials. NDIS's numerical simulation for aquifer horizontal movement is consistent with an analytic solution for horizontal motion in response to pumping from a leaky confined aquifer (Li, 2007). For purposes of comparison, vertical subsidence of the aquifer system in response to groundwater pumping is simulated by the both the NDIS and MODFLOW-SUB models. The results of the simulations show that land subsidence simulated by MODFLOW-SUB is significantly larger and less sensitive to pumping rate and time than that simulated by NDIS. The NDIS simulations also suggest that if the total pumpage is the same, pumping from a single well may induce more land subsidence than pumping from multiple wells.

  12. The simulation of 3D microcalcification clusters in 2D digital mammography and breast tomosynthesis

    SciTech Connect

    Shaheen, Eman; Van Ongeval, Chantal; Zanca, Federica; Cockmartin, Lesley; Marshall, Nicholas; Jacobs, Jurgen; Young, Kenneth C.; Dance, David R.; Bosmans, Hilde

    2011-12-15

    Purpose: This work proposes a new method of building 3D models of microcalcification clusters and describes the validation of their realistic appearance when simulated into 2D digital mammograms and into breast tomosynthesis images. Methods: A micro-CT unit was used to scan 23 breast biopsy specimens of microcalcification clusters with malignant and benign characteristics and their 3D reconstructed datasets were segmented to obtain 3D models of microcalcification clusters. These models were then adjusted for the x-ray spectrum used and for the system resolution and simulated into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. Six radiologists were asked to distinguish between 40 real and 40 simulated clusters of microcalcifications in two separate studies on 2D mammography and tomosynthesis datasets. Receiver operating characteristic (ROC) analysis was used to test the ability of each observer to distinguish between simulated and real microcalcification clusters. The kappa statistic was applied to assess how often the individual simulated and real microcalcification clusters had received similar scores (''agreement'') on their realistic appearance in both modalities. This analysis was performed for all readers and for the real and the simulated group of microcalcification clusters separately. ''Poor'' agreement would reflect radiologists' confusion between simulated and real clusters, i.e., lesions not systematically evaluated in both modalities as either simulated or real, and would therefore be interpreted as a success of the present models. Results: The area under the ROC curve, averaged over the observers, was 0.55 (95% confidence interval [0.44, 0.66]) for the 2D study, and 0.46 (95% confidence interval [0.29, 0.64]) for the tomosynthesis study, indicating no statistically significant difference between real and simulated

  13. Imaging Sand Bars using 3D GPR in an Outcrop Reservoir Analog: Cretaceous Ferron Sandstone, South-East Utah

    NASA Astrophysics Data System (ADS)

    Aziz, A. S.; Stewart, R. R.; Ullah, M. S.; Bhattacharya, J.

    2015-12-01

    Outcrop analog studies provide crucial information on geometry and facies patterns to improve the understanding of the complex subsurface reservoir architecture for enhanced oil recovery (EOR) planning during field development. Ground-penetrating radar (GPR) has greatly facilitated analog outcrop study progress by bridging the gap in image resolution between seismic and well data. A 3D GPR survey was conducted to visualize architectural elements of friction-dominated distributary mouth bars within proximal delta front deposits in Cretaceous Ferron Sandstone at the top of the Notom Delta in south-east Utah. Sensors and Software's Noggin 250 MHz system was used over a 25 m x 15 m grid. We employed a spatial sampling of 0.5 m for the inline (dip direction) and 1.5 m for the crossline (strike direction). Standard processing flows including time-zero correction, dewow, gain, background subtraction and 2D migration were used to increase the signal-to-noise ratio. Formation velocity estimates from the hyperbola matching yielded 0.131 m/ns which is comparable to the literature velocity of about 0.125 m/ns. The calculated average dielectric constant (directly related to volumetric water content) is 5.2 matches unsaturated sandstone. The depth of GPR penetration is limited to approximately 3 m - likely due to the compaction/carbonate cementation in the rock and interbedded layers of finer-grained material contributing to higher attenuation of the GPR signal. The vertical resolution is about 0.125 m, enabling the imaging of the dune-scale cross sets (15-20 cm thickness). Calculation of the medium porosity via an adapted Wyllie Time Average equation yields 7.8 % which is consistent with the average porosity (5-10%) obtained from the literature. Bedding diagrams from local cliff exposures in the previous studies show gently NE dipping accretion of single large foresets that were interpreted as small-scale unit bars, the amalgamation of which resulted in the progradation of

  14. Development of discrete gas kinetic scheme for simulation of 3D viscous incompressible and compressible flows

    NASA Astrophysics Data System (ADS)

    Yang, L. M.; Shu, C.; Wang, Y.; Sun, Y.

    2016-08-01

    The sphere function-based gas kinetic scheme (GKS), which was presented by Shu and his coworkers [23] for simulation of inviscid compressible flows, is extended to simulate 3D viscous incompressible and compressible flows in this work. Firstly, we use certain discrete points to represent the spherical surface in the phase velocity space. Then, integrals along the spherical surface for conservation forms of moments, which are needed to recover 3D Navier-Stokes equations, are approximated by integral quadrature. The basic requirement is that these conservation forms of moments can be exactly satisfied by weighted summation of distribution functions at discrete points. It was found that the integral quadrature by eight discrete points on the spherical surface, which forms the D3Q8 discrete velocity model, can exactly match the integral. In this way, the conservative variables and numerical fluxes can be computed by weighted summation of distribution functions at eight discrete points. That is, the application of complicated formulations resultant from integrals can be replaced by a simple solution process. Several numerical examples including laminar flat plate boundary layer, 3D lid-driven cavity flow, steady flow through a 90° bending square duct, transonic flow around DPW-W1 wing and supersonic flow around NACA0012 airfoil are chosen to validate the proposed scheme. Numerical results demonstrate that the present scheme can provide reasonable numerical results for 3D viscous flows.

  15. Numerical simulation of 3D boundary-driven acoustic streaming in microfluidic devices.

    PubMed

    Lei, Junjun; Hill, Martyn; Glynne-Jones, Peter

    2014-02-07

    This article discusses three-dimensional (3D) boundary-driven streaming in acoustofluidic devices. Firstly, the 3D Rayleigh streaming pattern in a microchannel is simulated and its effect on the movement of microparticles of various sizes is demonstrated. The results obtained from this model show good comparisons with 3D experimental visualisations and demonstrate the fully 3D nature of the acoustic streaming field and the associated acoustophoretic motion of microparticles in acoustofluidic devices. This method is then applied to another acoustofluidic device in order to gain insights into an unusual in-plane streaming pattern. The origin of this streaming has not been fully described and its characteristics cannot be explained from the classical theory of Rayleigh streaming. The simulated in-plane streaming pattern was in good agreement with the experimental visualisation. The mechanism behind it is shown to be related to the active sound intensity field, which supports our previous findings on the mechanism of the in-plane acoustic streaming pattern visualised and modelled in a thin-layered capillary device.

  16. 3D thermal modeling of TRISO fuel coupled with neutronic simulation

    SciTech Connect

    Hu, Jianwei; Uddin, Rizwan

    2010-01-01

    The Very High Temperature Gas Reactor (VHTR) is widely considered as one of the top candidates identified in the Next Generation Nuclear Power-plant (NGNP) Technology Roadmap under the U.S . Depanment of Energy's Generation IV program. TRlSO particle is a common element among different VHTR designs and its performance is critical to the safety and reliability of the whole reactor. A TRISO particle experiences complex thermo-mechanical changes during reactor operation in high temperature and high burnup conditions. TRISO fuel performance analysis requires evaluation of these changes on micro scale. Since most of these changes are temperature dependent, 3D thermal modeling of TRISO fuel is a crucial step of the whole analysis package. In this paper, a 3D numerical thermal model was developed to calculate temperature distribution inside TRISO and pebble under different scenarios. 3D simulation is required because pebbles or TRISOs are always subjected to asymmetric thermal conditions since they are randomly packed together. The numerical model was developed using finite difference method and it was benchmarked against ID analytical results and also results reported from literature. Monte-Carlo models were set up to calculate radial power density profile. Complex convective boundary condition was applied on the pebble outer surface. Three reactors were simulated using this model to calculate temperature distribution under different power levels. Two asymmetric boundary conditions were applied to the pebble to test the 3D capabilities. A gas bubble was hypothesized inside the TRISO kernel and 3D simulation was also carried out under this scenario. Intuition-coherent results were obtained and reported in this paper.

  17. Real-time 3D radiation risk assessment supporting simulation of work in nuclear environments.

    PubMed

    Szőke, I; Louka, M N; Bryntesen, T R; Bratteli, J; Edvardsen, S T; RøEitrheim, K K; Bodor, K

    2014-06-01

    This paper describes the latest developments at the Institute for Energy Technology (IFE) in Norway, in the field of real-time 3D (three-dimensional) radiation risk assessment for the support of work simulation in nuclear environments. 3D computer simulation can greatly facilitate efficient work planning, briefing, and training of workers. It can also support communication within and between work teams, and with advisors, regulators, the media and public, at all the stages of a nuclear installation's lifecycle. Furthermore, it is also a beneficial tool for reviewing current work practices in order to identify possible gaps in procedures, as well as to support the updating of international recommendations, dissemination of experience, and education of the current and future generation of workers.IFE has been involved in research and development into the application of 3D computer simulation and virtual reality (VR) technology to support work in radiological environments in the nuclear sector since the mid 1990s. During this process, two significant software tools have been developed, the VRdose system and the Halden Planner, and a number of publications have been produced to contribute to improving the safety culture in the nuclear industry.This paper describes the radiation risk assessment techniques applied in earlier versions of the VRdose system and the Halden Planner, for visualising radiation fields and calculating dose, and presents new developments towards implementing a flexible and up-to-date dosimetric package in these 3D software tools, based on new developments in the field of radiation protection. The latest versions of these 3D tools are capable of more accurate risk estimation, permit more flexibility via a range of user choices, and are applicable to a wider range of irradiation situations than their predecessors.

  18. A cut cell method for the 3D simulation of Crookes radiometer

    SciTech Connect

    Dechriste, Guillaume; Mieussens, Luc

    2014-12-09

    Devices involved in engineering applications, such as vacuum pumps or MEMS, may be made of several moving parts. This raise the issue of the simulation of rarefied gas flow around moving boundaries. We propose a simple process, known as cut cell method, to treat the motion of a solid body in the framework of the deterministic solving of a kinetic equation. Up to our knowledge, this is the first time that this approach has been used for this kind of simulations. The method is illustrated by the 2D and 3D simulations of a Crookes radiometer.

  19. A cut cell method for the 3D simulation of Crookes radiometer

    NASA Astrophysics Data System (ADS)

    Dechriste, Guillaume; Mieussens, Luc

    2014-12-01

    Devices involved in engineering applications, such as vacuum pumps or MEMS, may be made of several moving parts. This raise the issue of the simulation of rarefied gas flow around moving boundaries. We propose a simple process, known as cut cell method, to treat the motion of a solid body in the framework of the deterministic solving of a kinetic equation. Up to our knowledge, this is the first time that this approach has been used for this kind of simulations. The method is illustrated by the 2D and 3D simulations of a Crookes radiometer.

  20. Determination of key parameters of SEU occurrence using 3-D full cell SRAM simulations

    SciTech Connect

    Roche, P.; Palau, J.M.; Bruguier, G.; Tavernier, C.; Ecoffet, R.; Gasiot, J.

    1999-12-01

    A 3-D entire SRAM cell, based on a 0.35-{micro}m current CMOS technology, is simulated in this work with a DEVICE simulator. The transient current, resulting from a heavy ion strike in the most sensitive region of the cell, is studied as a function of the LET value, the cell layout and the ion penetration depth. A definition of the critical charge is proposed and two new methods are presented to compute this basic amount of charge only using SPICE simulations. Numerical applications are performed with two different generations of submicron CMOS technologies, including the determination of the sensitive thicknesses.

  1. Reactive Flow Modeling of Liquid Explosives via ALE3D/Cheetah Simulations

    SciTech Connect

    Kuo, I W; Bastea, S; Fried, L E

    2010-03-10

    We carried out reactive flow simulations of liquid explosives such as nitromethane using the hydrodynamic code ALE3D coupled with equations of state and reaction kinetics modeled by the thermochemical code Cheetah. The simulation set-up was chosen to mimic cylinder experiments. For pure unconfined nitromethane we find that the failure diameter and detonation velocity dependence on charge diameter are in agreement with available experimental results. Such simulations are likely to be useful for determining detonability and failure behavior for a wide range of experimental conditions and explosive compounds.

  2. Characteristics of tumor and host cells in 3-D simulated microgravity environment

    NASA Astrophysics Data System (ADS)

    Chopra, V.; Dinh, T.; Wood, T.; Pellis, N.; Hannigan, E.

    Co-cultures of three-dimensional (3-D) constructs of one cell type with dispersed cells of a second cell type in low-shear rotating suspension cultures in simulated microgravity environment have been used to investigate invasive properties of normal and malignant cell types. We have shown that the epithelial and endothelial cells undergo a switch in characteristics when grown in an in vitro 3-D environment, that mimics the in vivo host environment as compared with conventional two-dimensional (2-D) monolayer cultures. Histological preparations and immunohistochemical staining procedures of cocultured harvests demonstrated various markers of interest: like collagen vimentin, mucin, elastin, fibrin, fibrinogen, cytokeratin, adhesion molecules and various angiogenic factors by tumor cells from gynecological cancer patients along with fibroblasts, endothelial cells and patient-derived mononuclear cells (n=8). The growth rate was enhanced 10-15 folds by 3-D cocultures of patient-derived cells as compared with 2-D monolayer cultures and 3-D monocultures. The production of interleukin-2, interleukin-6, interleukin -8, vascular endothelial cell growth factor, basic fibroblast growth factor, and angiogenin was studied by using ELISA and RT- PCR. Human umbilical vein-derived endothelial cell (HUVEC) were used to study the mitogenic response of the conditioned medium collected from 3-D monocultures and cocultures during proliferation and migration assays. The conditioned medium collected from 3-D cocultures of cancer cells also 1) increased the expression of message levels of vascular endothelial growth factor and its receptor flt-1 and KDR was observed by HUVEC, and 2) increased the expression of intracellular and vascular cell adhesion molecules on the surface of HUVEC, when measured by using Live cell ELISA assays and immunofluorescent staining as compared with 3-D monocultures of normal epithelial cells. There was an increase in production of 1) enzymatic activity that

  3. Momentum Transport: 2D and 3D Cloud Resolving Model Simulations

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2001-01-01

    The major objective of this study is to investigate the momentum budgets associated with several convective systems that developed during the TOGA COARE IOP (west Pacific warm pool region) and GATE (east Atlantic region). The tool for this study is the improved Goddard Cumulas Ensemble (GCE) model which includes a 3-class ice-phase microphysical scheme, explicit cloud radiative interactive processes and air-sea interactive surface processes. The model domain contains 256 x 256 grid points (with 2 km resolution) in the horizontal and 38 grid points (to a depth of 22 km) in the vertical. The 2D domain has 1024 grid points. The simulations were performed over a 7-day time period (December 19-26, 1992, for TOGA COARE and September 1-7, 1994 for GATE). Cyclic literal boundary conditions are required for this type of long-term integration. Two well organized squall systems (TOGA, COARE February 22, 1993, and GATE September 12, 1994) were also simulated using the 3D GCE model. Only 9 h simulations were required to cover the life time of the squall systems. the lateral boundary conditions were open for these two squall systems simulations. the following will be examined: (1) the momentum budgets in the convective and stratiform regions, (2) the relationship between momentum transport and cloud organization (i.e., well organized squall lines versus less organized convective), (3) the differences and similarities in momentum transport between 2D and 3D simulated convective systems, and (4) the differences and similarities in momentum budgets between cloud systems simulated with open and cyclic lateral boundary conditions. Preliminary results indicate that there are only small differences between 2D and 3D simulated momentum budgets. Major differences occur, however, between momentum budgets associated with squall systems simulated using different lateral boundary conditions.

  4. Stability of 3D Textile Composite Reinforcement Simulations: Solutions to Spurious Transverse Modes

    NASA Astrophysics Data System (ADS)

    Mathieu, S.; Hamila, N.; Dupé, F.; Descamps, C.; Boisse, P.

    2016-08-01

    The simulation of thick 3D composite reinforcement forming brings to light new modeling challenges. The specific anisotropic material behavior due to the possible slippage between fibers induces, among other phenomena, the development of spurious transverse modes in bending-dominated 3D simulations. To obtain coherent finite element responses, two solutions are proposed. The first one uses a simple assumed strain formulation usually prescribed to prevent volumetric locking. This solution avoids spurious transverse modes by stiffening of the hourglass modes. Nevertheless the deformation obtained by this approach still suffers from the inability of the standard continuum mechanics of Cauchy to describe fibrous material deformation. The second proposed approach is based on the introduction of a bending stiffness which both avoids the spurious transverse modes and also improves the global behavior of the element formulation by enriching the underlying continuum. To emphasize the differences between different formulations, element stiffnesses are explicitly calculated and compared.

  5. Blob Dynamics in 3D BOUT Simulations of Tokamak Edge Turbulence

    SciTech Connect

    Russell, D; D'Ippolito, D; Myra, J; Nevins, W; Xu, X

    2004-08-23

    Propagating filaments of enhanced plasma density, or blobs, observed in 3D numerical simulations of a diverted, neutral-fueled tokamak are studied. Fluctuations of vorticity, electrical potential {phi}, temperature T{sub e} and current density J{sub {parallel}} associated with the blobs have a dipole structure perpendicular to the magnetic field and propagate radially with large E {center_dot} B drift velocities (> 1 km/s). The simulation results are consistent with a 3D blob dynamics model that incorporates increased parallel plasma resistivity (from neutral cooling of the X-point region), blob disconnection from the divertor sheath, X-point closure of the current loops, and collisional physics to sustain the {phi}, T{sub e}, J{sub {parallel}} dipoles.

  6. 3D Kinetic Simulation of Plasma Jet Penetration in Magnetic Field

    NASA Astrophysics Data System (ADS)

    Galkin, Sergei A.; Bogatu, I. N.; Kim, J. S.

    2009-11-01

    A high velocity plasmoid penetration through a magnetic barrier is a problem of a great experimental and theoretical interest. Our LSP PIC code 3D fully kinetic numerical simulations of high density (10^16 cm-3) high velocity (30-140 km/sec) plasma jet/bullet, penetrating through the transversal magnetic field, demonstrate three different regimes: reflection by field, penetration by magnetic field expulsion and penetration by magnetic self-polarization. The behavior depends on plasma jet parameters and its composition: hydrogen, carbon (A=12) and C60-fullerene (A=720) plasmas were investigated. The 3D simulation of two plasmoid head-on injections along uniform magnetic field lines is analyzed. Mini rail plasma gun (accelerator) modeling is also presented and discussed.

  7. Determination of porosity and facies trends in a complex carbonate reservoir, by using 3-D seismic, borehole tools, and outcrop geology

    SciTech Connect

    Zacharakis, T.G. Jr.; Comet, J.N.; Murillo, A.A.

    1996-08-01

    Mesozoic carbonate reservoirs are found in the Mediterranean Sea, off the east coast of Spain. A wide variation of porosities are found in the core samples and logs: vuggy, breccia, fractures, and cavern porosity. In addition, complex Tertiary carbonate geometries include olistostromes, breccia bodies, and reef buildups, which are found on top of Mesozoic carbonates. Predicting the porosity trends within these oil productive reservoirs requires an understanding of how primary porosity was further enhanced by secondary processes, including fractures, karstification, and dolomitization in burial conditions. Through an extensive investigation of field histories, outcrop geology, and seismic data, a series of basic reservoir styles have been identified and characterized by well log signature and seismic response. The distribution pattern of the different reservoirs styles is highly heterogeneous, but by integrating subsurface data and outcrop analogs, it is possible to distinguish field-scale and local patterns of both vertical and local variations in reservoir properties. Finally, it is important to quantify these reservoir properties through the study of seismic attributes, such as amplitude variations, and log responses at the reservoir interval. By incorporating 3-D seismic data, through the use of seismic inversion, it is possible to predict porosity trends. Further, the use of geostatistics can lead to the prediction of reservoir development within the carbonate facies.

  8. Effectiveness Evaluation of Force Protection Training Using Computer-Based Instruction and X3d Simulation

    DTIC Science & Technology

    2007-09-01

    to growing operational constraints accelerated by the Global War on Terror, the United States Navy is looking for alternative methods of training to...accomplished efficiently and effectively, saving the U.S. Navy time and resources while maintaining a high state of readiness. The goal of this thesis is...COMPUTER-BASED INSTRUCTION AND X3D SIMULATION Wilfredo Cruzbaez Lieutenant, United States Navy B.A., Norfolk State University, 2001 Submitted in

  9. Modeling and 3-D Simulation of Biofilm Dynamics in Aqueous Environment

    NASA Astrophysics Data System (ADS)

    Wang, Qi

    2011-11-01

    We present a complex fluid model for biofilms growing in an aqueous environment. The modeling approach represents a new paradigm to develop models for biofilm-environment interaction that can be used to systematically incorporate refined chemical and physiological mechanisms. Special solutions of the model are presented and analyzed. 3-D numerical simulations in aqueous environment with emphasis on biofilm- ambient fluid interaction will be discussed in detail.

  10. Rabi multi-sector reservoir simulation model

    SciTech Connect

    Bruijnzeels, C.; O`Halloran, C.

    1995-12-31

    To ensure optimum ultimate recovery of the 46 meter thick oil rim of the Rabi Field in Gabon, a full field simulation model was required. Due to it`s size and complexity, with local cusping, coning and geological circumstances dominating individual well behavior, a single full field model would be too large for existing hardware. A method was developed to simulate the full field with 5 separate sector models, whilst allowing the development in one sector model to have an effect on the boundary conditions of another sector. In this manner, the 13 x 4.5 km field could be simulated with a horizontal well spacing down to 175 meter. This paper focuses on the method used to attach single 3-phase tank cells to a sector simulation grid in order to represent non-simulated parts of the field. It also describes the history matching methodology and how to run a multisector model in forecasting mode. This method can be used for any reservoir, where size and complexity require large reservoir simulation models that normally could not be modeled within the constraints of available computer facilities. Detailed studies can be conducted on specific parts of a field, whilst allowing for dynamic flow and pressure effects caused by the rest of the field.

  11. Meso-Scale Damage Simulation of 3D Braided Composites under Quasi-Static Axial Tension

    NASA Astrophysics Data System (ADS)

    Zhang, Chao; Mao, Chunjian; Zhou, Yexin

    2017-01-01

    The microstructure of 3D braided composites is composed of three phases: braiding yarn, matrix and interface. In this paper, a representative unit-cell (RUC) model including these three phases is established. Coupling with the periodical boundary condition, the damage behavior of 3D braided composites under quasi-static axial tension is simulated by using finite element method based on this RUC model. An anisotropic damage model based on Murakami damage theory is proposed to predict the damage evolution of yarns and matrix; a damage-friction combination interface constitutive model is adopted to predict the interface debonding behavior. A user material subroutine (VUMAT) involving these damage models is developed and implemented in the finite element software ABAQUS/Explicit. The whole process of damage evolution of 3D braided composites under quasi-static axial tension with typical braiding angles is simulated, and the damage mechanisms are revealed in detail in the simulation process. The tensile strength properties of the braided composites are predicted from the calculated stress-strain curves. Numerical results agree with the available experiment data and thus validates the proposed damage analysis model. The effects of certain material parameters on the predicted stress-strain responses are also discussed by numerical parameter study.

  12. Simulation of a true-triaxial deformation test on anisotropic gneiss using FLAC3D

    NASA Astrophysics Data System (ADS)

    Ye, Shenghua; Sehizadeh, Mehdi; Nasseri, Mohammad; Young, Paul

    2016-04-01

    A series of true-triaxial experiments have been carried out at the University of Toronto's Rock Fracture Dynamics Laboratory. Isotropic pegmatite and gneiss have been used to systematically study the effect of anisotropy on the strength, behaviour and seismic response. Samples were loaded under true-triaxial stress conditions and subjected to complex loading and unloading histories associated with rock deformation around underground openings. The results show expected patterns of weakness from preferentially oriented samples and highlight the importance of unloading history under true-triaxial conditions on the deformation and seismic response of the samples. These tests have been used to validate a synthetic simulation using the Itasca FLAC3D numerical code. The paper describes the FLAC3D simulations of the complex true-triaxial loading and unloading history of the different anisotropic samples. Various parameters were created to describe the physico-mechanical properties of the synthetic rock samples. Foliation planes of preferential orientations with respect to the primary loading direction were added to the synthetic rock samples to reflect the anisotropy of the gneiss. These synthetic rock samples were subjected to the same loading and unloading paths as the real rock samples, and failed in the same mechanism as what was observed from the experiments, and thus it proved the validity of this numerical simulation with FLAC3D.

  13. Simulation and testing of a multichannel system for 3D sound localization

    NASA Astrophysics Data System (ADS)

    Matthews, Edward Albert

    Three-dimensional (3D) audio involves the ability to localize sound anywhere in a three-dimensional space. 3D audio can be used to provide the listener with the perception of moving sounds and can provide a realistic listening experience for applications such as gaming, video conferencing, movies, and concerts. The purpose of this research is to simulate and test 3D audio by incorporating auditory localization techniques in a multi-channel speaker system. The objective is to develop an algorithm that can place an audio event in a desired location by calculating and controlling the gain factors of each speaker. A MATLAB simulation displays the location of the speakers and perceived sound, which is verified through experimentation. The scenario in which the listener is not equidistant from each of the speakers is also investigated and simulated. This research is envisioned to lead to a better understanding of human localization of sound, and will contribute to a more realistic listening experience.

  14. 3D printing method for freeform fabrication of optical phantoms simulating heterogeneous biological tissue

    NASA Astrophysics Data System (ADS)

    Wang, Minjie; Shen, Shuwei; Yang, Jie; Dong, Erbao; Xu, Ronald

    2014-03-01

    The performance of biomedical optical imaging devices heavily relies on appropriate calibration. However, many of existing calibration phantoms for biomedical optical devices are based on homogenous materials without considering the multi-layer heterogeneous structures observed in biological tissue. Using such a phantom for optical calibration may result in measurement bias. To overcome this problem, we propose a 3D printing method for freeform fabrication of tissue simulating phantoms with multilayer heterogeneous structure. The phantom simulates not only the morphologic characteristics of biological tissue but also absorption and scattering properties. The printing system is based on a 3D motion platform with coordinated control of the DC motors. A special jet nozzle is designed to mix base, scattering, and absorption materials at different ratios. 3D tissue structures are fabricated through layer-by-layer printing with selective deposition of phantom materials of different ingredients. Different mixed ratios of base, scattering and absorption materials have been tested in order to optimize the printing outcome. A spectrometer and a tissue spectrophotometer are used for characterizing phantom absorption and scattering properties. The goal of this project is to fabricate skin tissue simulating phantoms as a traceable standard for the calibration of biomedical optical spectral devices.

  15. Understanding the mixing process in 3D microfluidic nozzle/diffuser systems: simulations and experiments

    NASA Astrophysics Data System (ADS)

    Sayah, Abdeljalil; Gijs, Martin A. M.

    2016-11-01

    We characterise computationally and experimentally a three-dimensional (3D) microfluidic passive mixer for various Reynolds numbers ranging from 1 to 100, corresponding to primary flow rates of 10-870 µl min-1. The 3D mixing channel is composed of multiple curved segments: circular arcs situated in the substrate plane and curved nozzle/diffuser elements normal to the substrate plane. Numerical simulation provides a detailed understanding of the mixing mechanism resulting from the geometrical topology of the mixer. These Comsol software-based simulations reveal the development of two secondary flows perpendicular to the primary flow: a swirling flow resulting from tangential injection of the flow into the nozzle holes and Dean vortices present in the circular arcs. These phenomena are particularly important at a Reynolds number larger than 30, where mixing occurs by chaotic advection. Experimentally, the 3D mixer is fabricated in a monolithic glass substrate by powder blasting machining, exploiting eroding powder beams at various angles of impact with respect to the substrate plane. Experimental mixing was characterised using two coloured dyes, showing nearly perfect mixing for a microfluidic footprint of the order of a few mm2, in good agreement with the simulations.

  16. 3D Numerical Simulation on the Sloshing Waves Excited by the Seismic Shacking

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Wu, Tso-Ren

    2016-04-01

    In the event of 2015 Nepal earthquake, a video clip broadcasted worldwide showed a violent water spilling in a hotel swimming pool. This sloshing phenomenon indicates a potential water loss in the sensitive facilities, e.g. the spent fuel pools in nuclear power plant, has to be taken into account carefully under the consideration of seismic-induced ground acceleration. In the previous studies, the simulation of sloshing mainly focused on the pressure force on the structure by using a simplified Spring-Mass Method developed in the field of solid mechanics. However, restricted by the assumptions of plane water surface and limited wave height, significant error will be made in evaluating the amount of water loss in the tank. In this paper, the computational fluid dynamical model, Splash3D, was adopted for studying the sloshing problem accurately. Splash3D solved 3D Navier-Stokes Equation directly with Large-Eddy Simulation (LES) turbulent closure. The Volume-of-fluid (VOF) method with piecewise linear interface calculation (PLIC) was used to track the complex breaking water surface. The time series acceleration of a design seismic was loaded to excite the water. With few restrictions from the assumptions, the accuracy of the simulation results were improved dramatically. A series model validations were conducted by compared to a 2D theoretical solution, and a 3D experimental data. Good comparisons can be seen. After the validation, we performed the simulation for considering a sloshing case in a rectangular water tank with a dimension of 12 m long, 8 m wide, 8 m deep, which contained water with 7 m in depth. The seismic movement was imported by considering time-series acceleration in three dimensions, which were about 0.5 g to 1.2 g in the horizontal directions, and 0.3 g to 1 g in the vertical direction. We focused the discussions on the kinematics of the water surface, wave breaking, velocity field, pressure field, water force on the side walls, and, most

  17. High Resolution 3D Simulations of the Impacts of Asteroids into the Venusian Atmosphere

    NASA Astrophysics Data System (ADS)

    Korycansky, D. G.; Zahnle, K. J.; Mac Low, M.-M.

    2000-10-01

    We compare high-resolution 2D and 3D numerical hydrocode simulations of asteroids striking the atmosphere of Venus. Our focus is on aerobraking and its effect on the size of impact craters. We consider impacts both by spheres and by the real asteroid 4769 Castalia, a severely nonspherical body in a Venus-crossing orbit. We compute mass and momentum fluxes as functions of altitude as global measures of the asteroid's progress. We find that, on average, the 2D and 3D simulations are in broad agreement over how quickly an asteroid slows down, but that the scatter about the average is much larger for the 2D models than for the 3D models. The 2D models appear to be strongly susceptible to the ``butterfly effect'', in which tiny changes in initial conditions (e.g., 0.05% change in the impact velocity) produce quite different chaotic evolutions. By contrast the global properties of the 3D models appear more reproducible despite seemingly large differences in initial conditions. We argue that this difference between 2D and 3D models has its root in the greater geometrical constraints present in any 2D model, and in particular in the conservation of enstrophy in 2D that forces energy to pool in large-scale structures. It is the interaction of these artificial large-scale structures that causes slightly different 2D models to diverge so greatly. These constraints do not apply in 3D and large scale structures are not observed to form. A one-parameter modified pancake model reproduces the crater-forming potential of the 3D Castalias quite well. This work was supported by NASA's Exobiology and Planetary Atmospheres Programs. Image rendering was done using the resources of UCSC Vizualizaton Lab. M-MML is partially supported by a CAREER fellowship from the US NSF. This work was partially supported by the National Computational Science Alliance, utilizing the NCSA SGI/CRAY Power Challenge array at the University of Illinois, Urbana-Champaign.

  18. Metos3D: the Marine Ecosystem Toolkit for Optimization and Simulation in 3-D - Part 1: Simulation Package v0.3.2

    NASA Astrophysics Data System (ADS)

    Piwonski, Jaroslaw; Slawig, Thomas

    2016-10-01

    We designed and implemented a modular software framework for the offline simulation of steady cycles of 3-D marine ecosystem models based on the transport matrix approach. It is intended for parameter optimization and model assessment experiments. We defined a software interface for the coupling of a general class of water column-based biogeochemical models, with six models being part of the package. The framework offers both spin-up/fixed-point iteration and a Jacobian-free Newton method for the computation of steady states. The simulation package has been tested with all six models. The Newton method converged for four models when using standard settings, and for two more complex models after alteration of a solver parameter or the initial guess. Both methods delivered the same steady states (within a reasonable precision) on convergence for all models employed, with the Newton iteration generally operating 6 times faster. The effects on performance of both the biogeochemical and the Newton solver parameters were investigated for one model. A profiling analysis was performed for all models used in this work, demonstrating that the number of tracers had a dominant impact on overall performance. We also implemented a geometry-adapted load balancing procedure which showed close to optimal scalability up to a high number of parallel processors.

  19. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N. P. Paulsson

    2006-09-30

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to perform high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology has been hampered by the lack of acquisition technology necessary to record large volumes of high frequency, high signal-to-noise-ratio borehole seismic data. This project took aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array has removed the technical acquisition barrier for recording the data volumes necessary to do high resolution 3D VSP and 3D cross-well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that promise to take the gas industry to the next level in their quest for higher resolution images of deep and complex oil and gas reservoirs. Today only a fraction of the oil or gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of detailed compartmentalization of oil and gas reservoirs. In this project, we developed a 400 level 3C borehole seismic receiver array that allows for economic use of 3D borehole seismic imaging for reservoir characterization and monitoring. This new array has significantly increased the efficiency of recording large data volumes at sufficiently dense spatial sampling to resolve reservoir complexities. The receiver pods have been fabricated and tested to withstand high temperature (200 C/400 F) and high pressure (25,000 psi), so that they can operate in wells up to 7,620 meters (25,000 feet) deep. The receiver array is deployed on standard production or drill tubing. In combination with 3C surface seismic or 3C borehole seismic sources, the 400

  20. The Impact of 3D Data Quality on Improving GNSS Performance Using City Models Initial Simulations

    NASA Astrophysics Data System (ADS)

    Ellul, C.; Adjrad, M.; Groves, P.

    2016-10-01

    There is an increasing demand for highly accurate positioning information in urban areas, to support applications such as people and vehicle tracking, real-time air quality detection and navigation. However systems such as GPS typically perform poorly in dense urban areas. A number of authors have made use of 3D city models to enhance accuracy, obtaining good results, but to date the influence of the quality of the 3D city model on these results has not been tested. This paper addresses the following question: how does the quality, and in particular the variation in height, level of generalization and completeness and currency of a 3D dataset, impact the results obtained for the preliminary calculations in a process known as Shadow Matching, which takes into account not only where satellite signals are visible on the street but also where they are predicted to be absent. We describe initial simulations to address this issue, examining the variation in elevation angle - i.e. the angle above which the satellite is visible, for three 3D city models in a test area in London, and note that even within one dataset using different available height values could cause a difference in elevation angle of up to 29°. Missing or extra buildings result in an elevation variation of around 85°. Variations such as these can significantly influence the predicted satellite visibility which will then not correspond to that experienced on the ground, reducing the accuracy of the resulting Shadow Matching process.

  1. OptogenSIM: a 3D Monte Carlo simulation platform for light delivery design in optogenetics

    PubMed Central

    Liu, Yuming; Jacques, Steven L.; Azimipour, Mehdi; Rogers, Jeremy D.; Pashaie, Ramin; Eliceiri, Kevin W.

    2015-01-01

    Optimizing light delivery for optogenetics is critical in order to accurately stimulate the neurons of interest while reducing nonspecific effects such as tissue heating or photodamage. Light distribution is typically predicted using the assumption of tissue homogeneity, which oversimplifies light transport in heterogeneous brain. Here, we present an open-source 3D simulation platform, OptogenSIM, which eliminates this assumption. This platform integrates a voxel-based 3D Monte Carlo model, generic optical property models of brain tissues, and a well-defined 3D mouse brain tissue atlas. The application of this platform in brain data models demonstrates that brain heterogeneity has moderate to significant impact depending on application conditions. Estimated light density contours can show the region of any specified power density in the 3D brain space and thus can help optimize the light delivery settings, such as the optical fiber position, fiber diameter, fiber numerical aperture, light wavelength and power. OptogenSIM is freely available and can be easily adapted to incorporate additional brain atlases. PMID:26713200

  2. Compositional reservoir simulation in parallel supercomputing environments

    SciTech Connect

    Briens, F.J.L. ); Wu, C.H. ); Gazdag, J.; Wang, H.H. )

    1991-09-01

    A large-scale compositional reservoir simulation ({gt}1,000 cells) is not often run on a conventional mainframe computer owing to excessive turnaround times. This paper presents programming and computational techniques that fully exploit the capabilities of parallel supercomputers for a large-scale compositional simulation. A novel algorithm called sequential staging of tasks (SST) that can take full advantage of parallel-vector processing to speed up the solution of a large linear system is introduced. The effectiveness of SST is illustrated with results from computer experiments conducted on an IBM 3090-600E.

  3. Spatial distribution of hydrocarbon reservoirs in the West Korea Bay Basin in the northern part of the Yellow Sea, estimated by 3-D gravity forward modelling

    NASA Astrophysics Data System (ADS)

    Choi, Sungchan; Ryu, In-Chang; Götze, H.-J.; Chae, Y.

    2017-01-01

    Although an amount of hydrocarbon has been discovered in the West Korea Bay Basin (WKBB), located in the North Korean offshore area, geophysical investigations associated with these hydrocarbon reservoirs are not permitted because of the current geopolitical situation. Interpretation of satellite-derived potential field data can be alternatively used to image the 3-D density distribution in the sedimentary basin associated with hydrocarbon deposits. We interpreted the TRIDENT satellite-derived gravity field data to provide detailed insights into the spatial distribution of sedimentary density structures in the WKBB. We used 3-D forward density modelling for the interpretation that incorporated constraints from existing geological and geophysical information. The gravity data interpretation and the 3-D forward modelling showed that there are two modelled areas in the central subbasin that are characterized by very low density structures, with a maximum density of about 2000 kg m-3, indicating some type of hydrocarbon reservoir. One of the anticipated hydrocarbon reservoirs is located in the southern part of the central subbasin with a volume of about 250 km3 at a depth of about 3000 m in the Cretaceous/Jurassic layer. The other hydrocarbon reservoir should exist in the northern part of the central subbasin, with an average volume of about 300 km3 at a depth of about 2500 m.

  4. Spatial distribution of Hydrocarbon Reservoirs in the West Korea Bay Basin in the northern part of the Yellow Sea, estimated by 3D gravity forward modeling

    NASA Astrophysics Data System (ADS)

    Choi, Sungchan; Ryu, In-Chang; Götze, H.-J.; Chae, Y.

    2016-10-01

    Although an amount of hydrocarbon has been discovered in the West Korea Bay Basin (WKBB), located in the North Korean offshore area, geophysical investigations associated with these hydrocarbon reservoirs are not permitted because of the current geopolitical situation. Interpretation of satellite- derived potential field data can be alternatively used to image the three-dimensional (3D) density distribution in the sedimentary basin associated with hydrocarbon deposits. We interpreted the TRIDENT satellite-derived gravity field data to provide detailed insights into the spatial distribution of sedimentary density structures in the WKBB. We used 3D forward density modeling for the interpretation that incorporated constraints from existing geological and geophysical information. The gravity data interpretation and the 3D forward modeling showed that there are two modeled areas in the central subbasin that are characterized by very low density structures, with a maximum density of about 2000 kg/m3, indicating some type of hydrocarbon reservoir. One of the anticipated hydrocarbon reservoirs is located in the southern part of the central subbasin with a volume of about 250 km3 at a depth of about 3000 m in the Cretaceous/Jurassic layer. The other hydrocarbon reservoir should exist in the northern part of the central subbasin, with an average volume of about 300 km3 at a depth of about 2500 m.

  5. Sedimentary basin effects in Seattle, Washington: Ground-motion observations and 3D simulations

    USGS Publications Warehouse

    Frankel, Arthur; Stephenson, William; Carver, David

    2009-01-01

    Seismograms of local earthquakes recorded in Seattle exhibit surface waves in the Seattle basin and basin-edge focusing of S waves. Spectral ratios of Swaves and later arrivals at 1 Hz for stiff-soil sites in the Seattle basin show a dependence on the direction to the earthquake, with earthquakes to the south and southwest producing higher average amplification. Earthquakes to the southwest typically produce larger basin surface waves relative to S waves than earthquakes to the north and northwest, probably because of the velocity contrast across the Seattle fault along the southern margin of the Seattle basin. S to P conversions are observed for some events and are likely converted at the bottom of the Seattle basin. We model five earthquakes, including the M 6.8 Nisqually earthquake, using 3D finite-difference simulations accurate up to 1 Hz. The simulations reproduce the observed dependence of amplification on the direction to the earthquake. The simulations generally match the timing and character of basin surface waves observed for many events. The 3D simulation for the Nisqually earth-quake produces focusing of S waves along the southern margin of the Seattle basin near the area in west Seattle that experienced increased chimney damage from the earthquake, similar to the results of the higher-frequency 2D simulation reported by Stephenson et al. (2006). Waveforms from the 3D simulations show reasonable agreement with the data at low frequencies (0.2-0.4 Hz) for the Nisqually earthquake and an M 4.8 deep earthquake west of Seattle.

  6. Implementation of Headtracking and 3D Stereo with Unity and VRPN for Computer Simulations

    NASA Technical Reports Server (NTRS)

    Noyes, Matthew A.

    2013-01-01

    This paper explores low-cost hardware and software methods to provide depth cues traditionally absent in monocular displays. The use of a VRPN server in conjunction with a Microsoft Kinect and/or Nintendo Wiimote to provide head tracking information to a Unity application, and NVIDIA 3D Vision for retinal disparity support, is discussed. Methods are suggested to implement this technology with NASA's EDGE simulation graphics package, along with potential caveats. Finally, future applications of this technology to astronaut crew training, particularly when combined with an omnidirectional treadmill for virtual locomotion and NASA's ARGOS system for reduced gravity simulation, are discussed.

  7. Improving light propagation Monte Carlo simulations with accurate 3D modeling of skin tissue

    SciTech Connect

    Paquit, Vincent C; Price, Jeffery R; Meriaudeau, Fabrice; Tobin Jr, Kenneth William

    2008-01-01

    In this paper, we present a 3D light propagation model to simulate multispectral reflectance images of large skin surface areas. In particular, we aim to simulate more accurately the effects of various physiological properties of the skin in the case of subcutaneous vein imaging compared to existing models. Our method combines a Monte Carlo light propagation model, a realistic three-dimensional model of the skin using parametric surfaces and a vision system for data acquisition. We describe our model in detail, present results from the Monte Carlo modeling and compare our results with those obtained with a well established Monte Carlo model and with real skin reflectance images.

  8. 2-D and 3-D PIC simulations of a SLAC Klystrino

    NASA Astrophysics Data System (ADS)

    Spencer, Thomas; Luginsland, John; Hackett, Kirk; Haworth, Michael; Song, Liqun; Scheitrum, Glenn

    2000-10-01

    The Air Force Research Laboratory is collaborating with the Stanford Linear Accelerator Center in performing 3-D PIC simulations using ARGUS and ICEPIC on a klystrino with the following parameters: voltage of 110 kV, current of 2.4 A, frequency of 94 GHz, peak magnetic field of 4 kG. Results wll be presented and will be compared to 2-D MAGIC simulations, as well as to experimental test data. This work is supported in part by the Air Force Office of Scientific Research.

  9. Numerical simulation of the 3D unsteady turbulent flow in a combustion chamber

    NASA Astrophysics Data System (ADS)

    Stuparu, Adrian; Holotescu, Sorin

    2011-06-01

    The influence of turbulence models on the 3D unsteady flow in a combustion chamber with a central bluff body is analyzed. Three different turbulence models are used (realizable k-ɛ, Reynolds Stress Model and Large Eddy Simulation) and a comparison is made on the evolution of the velocity field over time. The numerical simulation of the gas flow in the combustion chamber was performed using FLUENT 6.3 software and the computational geometry, consisting of a structured mesh with 810,000 cells, was built using the pre-processor GAMBIT 2.4. The extent of the recirculation region behind the bluff body was determined for each turbulence model.

  10. Numerical simulation of the 3D unsteady turbulent flow in a combustion chamber

    NASA Astrophysics Data System (ADS)

    Stuparu, Adrian; Holotescu, Sorin

    2011-06-01

    The influence of turbulence models on the 3D unsteady flow in a combustion chamber with a central bluff body is analyzed. Three different turbulence models are used ( realizable k-ɛ, Reynolds Stress Model and Large Eddy Simulation) and a comparison is made on the evolution of the velocity field over time. The numerical simulation of the gas flow in the combustion chamber was performed using FLUENT 6.3 software and the computational geometry, consisting of a structured mesh with 810,000 cells, was built using the pre-processor GAMBIT 2.4. The extent of the recirculation region behind the bluff body was determined for each turbulence model.

  11. Simulation of the impact of 3-D porosity distribution in metallic U-10Zr fuels

    NASA Astrophysics Data System (ADS)

    Yun, Di; Yacout, Abdellatif M.; Stan, Marius; Bauer, Theodore H.; Wright, Arthur E.

    2014-05-01

    Evolution of porosity generated in metallic U-Zr fuel irradiated in fast spectrum reactors leads to changes in fuel properties and impacts important phenomena such as heat transport and constituent redistribution. The porosity is generated as a result of the accumulation of fission gases and is affected by the possible bond sodium infiltration into the fuel. Typically, the impact of porosity development on properties, such as thermal conductivity, is accounted for through empirical correlations that are dependent on porosity and infiltrated sodium fractions. Currently available simulation tools make it possible to take into account fuel 3-D porosity distributions, potentially eliminating the need for such correlations. This development allows for a more realistic representation of the porosity evolution in metallic fuel and creates a framework for truly mechanistic fuel development models. In this work, COMSOL multi-physics simulation platform is used to model 3-D porosity distributions and simulate heat transport in metallic U-10Zr fuel. Available experimental data regarding microstructural evolution of fuel that was irradiated in EBR-II and associated phase stability information are used to guide the simulation. The impact of changes in porosity characteristics on material properties is estimated and the results are compared with calculated temperature distributions. The simulations demonstrate the developed capability and importance of accounting for detailed porosity distribution features for accurate fuel performance evaluation.

  12. Performance of dental students versus prosthodontics residents on a 3D immersive haptic simulator.

    PubMed

    Eve, Elizabeth J; Koo, Samuel; Alshihri, Abdulmonem A; Cormier, Jeremy; Kozhenikov, Maria; Donoff, R Bruce; Karimbux, Nadeem Y

    2014-04-01

    This study evaluated the performance of dental students versus prosthodontics residents on a simulated caries removal exercise using a newly designed, 3D immersive haptic simulator. The intent of this study was to provide an initial assessment of the simulator's construct validity, which in the context of this experiment was defined as its ability to detect a statistically significant performance difference between novice dental students (n=12) and experienced prosthodontics residents (n=14). Both groups received equivalent calibration training on the simulator and repeated the same caries removal exercise three times. Novice and experienced subjects' average performance differed significantly on the caries removal exercise with respect to the percentage of carious lesion removed and volume of surrounding sound tooth structure removed (p<0.05). Experienced subjects removed a greater portion of the carious lesion, but also a greater volume of the surrounding tooth structure. Efficiency, defined as percentage of carious lesion removed over drilling time, improved significantly over the course of the experiment for both novice and experienced subjects (p<0.001). Within the limitations of this study, experienced subjects removed a greater portion of carious lesion on a 3D immersive haptic simulator. These results are a first step in establishing the validity of this device.

  13. Method for identifying subsurface fluid migration and drainage pathways in and among oil and gas reservoirs using 3-D and 4-D seismic imaging

    DOEpatents

    Anderson, R.N.; Boulanger, A.; Bagdonas, E.P.; Xu, L.; He, W.

    1996-12-17

    The invention utilizes 3-D and 4-D seismic surveys as a means of deriving information useful in petroleum exploration and reservoir management. The methods use both single seismic surveys (3-D) and multiple seismic surveys separated in time (4-D) of a region of interest to determine large scale migration pathways within sedimentary basins, and fine scale drainage structure and oil-water-gas regions within individual petroleum producing reservoirs. Such structure is identified using pattern recognition tools which define the regions of interest. The 4-D seismic data sets may be used for data completion for large scale structure where time intervals between surveys do not allow for dynamic evolution. The 4-D seismic data sets also may be used to find variations over time of small scale structure within individual reservoirs which may be used to identify petroleum drainage pathways, oil-water-gas regions and, hence, attractive drilling targets. After spatial orientation, and amplitude and frequency matching of the multiple seismic data sets, High Amplitude Event (HAE) regions consistent with the presence of petroleum are identified using seismic attribute analysis. High Amplitude Regions are grown and interconnected to establish plumbing networks on the large scale and reservoir structure on the small scale. Small scale variations over time between seismic surveys within individual reservoirs are identified and used to identify drainage patterns and bypassed petroleum to be recovered. The location of such drainage patterns and bypassed petroleum may be used to site wells. 22 figs.

  14. Method for identifying subsurface fluid migration and drainage pathways in and among oil and gas reservoirs using 3-D and 4-D seismic imaging

    DOEpatents

    Anderson, Roger N.; Boulanger, Albert; Bagdonas, Edward P.; Xu, Liqing; He, Wei

    1996-01-01

    The invention utilizes 3-D and 4-D seismic surveys as a means of deriving information useful in petroleum exploration and reservoir management. The methods use both single seismic surveys (3-D) and multiple seismic surveys separated in time (4-D) of a region of interest to determine large scale migration pathways within sedimentary basins, and fine scale drainage structure and oil-water-gas regions within individual petroleum producing reservoirs. Such structure is identified using pattern recognition tools which define the regions of interest. The 4-D seismic data sets may be used for data completion for large scale structure where time intervals between surveys do not allow for dynamic evolution. The 4-D seismic data sets also may be used to find variations over time of small scale structure within individual reservoirs which may be used to identify petroleum drainage pathways, oil-water-gas regions and, hence, attractive drilling targets. After spatial orientation, and amplitude and frequency matching of the multiple seismic data sets, High Amplitude Event (HAE) regions consistent with the presence of petroleum are identified using seismic attribute analysis. High Amplitude Regions are grown and interconnected to establish plumbing networks on the large scale and reservoir structure on the small scale. Small scale variations over time between seismic surveys within individual reservoirs are identified and used to identify drainage patterns and bypassed petroleum to be recovered. The location of such drainage patterns and bypassed petroleum may be used to site wells.

  15. Full Core 3-D Simulation of a Partial MOX LWR Core

    SciTech Connect

    S. Bays; W. Skerjanc; M. Pope

    2009-05-01

    A comparative analysis and comparison of results obtained between 2-D lattice calculations and 3-D full core nodal calculations, in the frame of MOX fuel design, was conducted. This study revealed a set of advantages and disadvantages, with respect to each method, which can be used to guide the level of accuracy desired for future fuel and fuel cycle calculations. For the purpose of isotopic generation for fuel cycle analyses, the approach of using a 2-D lattice code (i.e., fuel assembly in infinite lattice) gave reasonable predictions of uranium and plutonium isotope concentrations at the predicted 3-D core simulation batch average discharge burnup. However, it was found that the 2-D lattice calculation can under-predict the power of pins located along a shared edge between MOX and UO2 by as much as 20%. In this analysis, this error did not occur in the peak pin. However, this was a coincidence and does not rule out the possibility that the peak pin could occur in a lattice position with high calculation uncertainty in future un-optimized studies. Another important consideration in realistic fuel design is the prediction of the peak axial burnup and neutron fluence. The use of 3-D core simulation gave peak burnup conditions, at the pellet level, to be approximately 1.4 times greater than what can be predicted using back-of-the-envelope assumptions of average specific power and irradiation time.

  16. One-dimensional simulation of stratification and dissolved oxygen in McCook Reservoir, Illinois

    USGS Publications Warehouse

    Robertson, Dale M.

    2000-01-01

    As part of the Chicagoland Underflow Plan/Tunnel and Reservoir Plan, the U.S. Army Corps of Engineers, Chicago District, plans to build McCook Reservoir.a flood-control reservoir to store combined stormwater and raw sewage (combined sewage). To prevent the combined sewage in the reservoir from becoming anoxic and producing hydrogen sulfide gas, a coarse-bubble aeration system will be designed and installed on the basis of results from CUP 0-D, a zero-dimensional model, and MAC3D, a three-dimensional model. Two inherent assumptions in the application of MAC3D are that density stratification in the simulated water body is minimal or not present and that surface heat transfers are unimportant and, therefore, may be neglected. To test these assumptions, the previously tested, one-dimensional Dynamic Lake Model (DLM) was used to simulate changes in temperature and dissolved oxygen in the reservoir after a 1-in-100-year event. Results from model simulations indicate that the assumptions made in MAC3D application are valid as long as the aeration system, with an air-flow rate of 1.2 cubic meters per second or more, is operated while the combined sewage is stored in the reservoir. Results also indicate that the high biochemical oxygen demand of the combined sewage will quickly consume the dissolved oxygen stored in the reservoir and the dissolved oxygen transferred through the surface of the reservoir; therefore, oxygen must be supplied by either the rising bubbles of the aeration system (a process not incorporated in DLM) or some other technique to prevent anoxia.

  17. Reconstruction of quadratic curves in 3D using two or more perspective views: simulation studies

    NASA Astrophysics Data System (ADS)

    Kumar, Sanjeev; Sukavanam, N.; Balasubramanian, R.

    2006-01-01

    The shapes of many natural and man-made objects have planar and curvilinear surfaces. The images of such curves usually do not have sufficient distinctive features to apply conventional feature-based reconstruction algorithms. In this paper, we describe a method of reconstruction of a quadratic curve in 3-D space as an intersection of two cones containing the respective projected curve images. The correspondence between this pair of projections of the curve is assumed to be established in this work. Using least-square curve fitting, the parameters of a curve in 2-D space are found. From this we are reconstructing the 3-D quadratic curve. Relevant mathematical formulations and analytical solutions for obtaining the equation of reconstructed curve are given. The result of the described reconstruction methodology are studied by simulation studies. This reconstruction methodology is applicable to LBW decision in cricket, path of the missile, Robotic Vision, path lanning etc.

  18. Anomalous Surface Deformation of Sapphire Clarified by 3D-FEM Simulation of the Nanoindentation

    NASA Astrophysics Data System (ADS)

    Nowak, Roman; Manninen, Timo; Li, Chunliang; Heiskanen, Kari; Hannula, Simo-Pekka; Lindroos, Veikko; Soga, Tetsuo; Yoshida, Fusahito

    This work clarifies the origin of anomalous surface deformation reflected by peculiar surface patterns around indentation impressions on various crystallographic planes of sapphire. The three-dimensional finite element simulation (3D-FEM) of nanoindentation in Al2O3 crystal allowed the authors to localize the regions in which various kinds of twinning and slip are most prone to be activated. The work provides a novel approach to the “hardness anisotropy”, which was modeled so far using a modified uniaxial-stress approximation of this essentially 3D, non-isotropic contact problem. The calculated results enabled the authors to unravel the asymmetric surface deformation detected on prismatic planes by the high-resolution microscopy, which cannot be explained using simple crystallographic considerations.

  19. Application of FUN3D Solver for Aeroacoustics Simulation of a Nose Landing Gear Configuration

    NASA Technical Reports Server (NTRS)

    Vatsa, Veer N.; Lockard, David P.; Khorrami, Mehdi R.

    2011-01-01

    Numerical simulations have been performed for a nose landing gear configuration corresponding to the experimental tests conducted in the Basic Aerodynamic Research Tunnel at NASA Langley Research Center. A widely used unstructured grid code, FUN3D, is examined for solving the unsteady flow field associated with this configuration. A series of successively finer unstructured grids has been generated to assess the effect of grid refinement. Solutions have been obtained on purely tetrahedral grids as well as mixed element grids using hybrid RANS/LES turbulence models. The agreement of FUN3D solutions with experimental data on the same size mesh is better on mixed element grids compared to pure tetrahedral grids, and in general improves with grid refinement.

  20. Mapping 3D thin shale and permeability pathway within a reservoir system: Case study from the Sleipner Field

    NASA Astrophysics Data System (ADS)

    Ponfa Bitrus, Roy; Iacopini, David; Bond, Clare

    2016-04-01

    Reservoir architecture plays an integral part of seismic reservoir characterization. The characteristics of a reservoir which includes its external and internal geometry are important as they influence the production and development strategy employed in the oil and gas sector. Reservoir architecture is defined by the interpretation of seismic data, thus identifying the basic structural and stratigraphic geometrical framework of a trapping and flow system for hydrocarbon and fluids. One major issue though is the interpretation of thin shales and identification of permeability pathways within the reservoir system. This paper employs a method using attributes to map thin shales and identify permeability pathways or transmissitives that exist within a reservoir taking into consideration the seismic resolution and available data. Case study is the Utsira Formation in the Sleipner field, Norwegian North sea. The Utsira formation presents a classic case of thin beds within a sandstone formation and transmissitives that exist as chimneys within the formation. A total of 10 intra reservoir horizon units of shales where interpreted using complex trace seismic attributes. These interpreted horizons where further analysed through spectral decomposition to reveal possible facies distribution and unit thickness within the horizon. Reservoir transmissitives identified as vertical curvilinear structures were also analysed using unique seismic attributes in other to delineate their extent and characterise their occurrence These interpreted shales and pathway transmissitives illuminate the geometry of the formation, the reservoir heterogeneities on a finer-scale and, in the long term, constrain the migration prediction of reservoir fluids, hydrocarbons and injected CO2 when matched across a 4D seismic data survey. As such, useful insights into the key elements operating within the reservoir can be provided, giving a good indication of the long and short term reservoir performance.

  1. Methods to improve the resolution of prestack migrated images, with application to a 3D dataset from a fractured reservoir

    NASA Astrophysics Data System (ADS)

    Perez, Gabriel

    I present three different methods to achieve increased definition in images from conventional seismic data, as illustrated with 3D data from the Fort Worth Basin's Barnett Shale fractured reservoir play, currently one of the hottest exploration and production trends in continental U.S. First, I present a method to correct for wavelet stretch in common-angle prestack migrated data. Wavelet stretch adversely influences contributions to the image from large angle or long offset data. Increasing the fidelity of large angles improves the vertical and lateral resolution in images from seismic data and from derived attributes, and positively impact AVA/AVO analysis. Achieving the greatest potential of this technique demands that I address the increased sensitivity to velocity errors and anisotropy. The other two methods presented here benefit from the balance in spectral content of the imaged data across angles and the increased resolution that are achieved from correcting for wavelet stretch. Then I introduce a new way to define azimuth binning in Kirchhoff prestack migration. This approach avoids mixing the typically weaker side-scattered energy with the stronger reflections from the sagittal plane. With the modified binning, signal and noise events are preferentially imaged in azimuth orientations normal to their apparent strike orientation, in surface- or map-views. This modified azimuthal binning also results in improved detection of out-of-the-plane steeply dipping reflectors, fractures and faults and their orientation, especially when combined with attributes such as curvature and coherence. Finally, I present an approach to measure lateral misalignment in prestack migrated seismic images and then correct for it by applying a warping procedure to these images. Though velocity errors are the most likely source for misalignment between images, it can also result from other imperfections in the imaging procedure. Lateral misalignment is most easily recognized and

  2. Lightning strike simulation using coaxial line technique and 3D linear injection current analysis

    NASA Astrophysics Data System (ADS)

    Flourens, F.; Gauthier, D.; Serafin, D.

    1989-09-01

    The GORFFD code for determining aircraft responses to either a lightning event or to simulated current injection is based on the finite-difference solution of Maxwell's equation, and allows the simulation of complex, 3D metallic and dielectric composite structures. A transfer method is used to analyze the EM environment associated with in-flight measurements. Attention is given to a linear-analysis numerical model in which the lightning channel is simulated as a thin wire that is driven by a current source. Surface E-fields and current mappings are produced for the Transall transport and Mirage fighter aircraft. An experimental method has been devised for verification of these lightning-strike simulations.

  3. Toward high-speed 3D nonlinear soft tissue deformation simulations using Abaqus software.

    PubMed

    Idkaidek, Ashraf; Jasiuk, Iwona

    2015-12-01

    We aim to achieve a fast and accurate three-dimensional (3D) simulation of a porcine liver deformation under a surgical tool pressure using the commercial finite element software Abaqus. The liver geometry is obtained using magnetic resonance imaging, and a nonlinear constitutive law is employed to capture large deformations of the tissue. Effects of implicit versus explicit analysis schemes, element type, and mesh density on computation time are studied. We find that Abaqus explicit and implicit solvers are capable of simulating nonlinear soft tissue deformations accurately using first-order tetrahedral elements in a relatively short time by optimizing the element size. This study provides new insights and guidance on accurate and relatively fast nonlinear soft tissue simulations. Such simulations can provide force feedback during robotic surgery and allow visualization of tissue deformations for surgery planning and training of surgical residents.

  4. Numerical simulation of pulsation processes in hydraulic turbine based on 3D model of cavitating flow

    NASA Astrophysics Data System (ADS)

    Panov, L. V.; Chirkov, D. V.; Cherny, S. G.; Pylev, I. M.

    2014-01-01

    A new approach was proposed for simulation of unsteady cavitating flow in the flow passage of a hydraulic power plant. 1D hydro-acoustics equations are solved in the penstock domain. 3D equations of turbulent flow of isothermal compressible liquid-vapor mixture are solved in the turbine domain. Cavitation is described by a transfer equation for liquid phase with a source term which is responsible for evaporation and condensation. The developed method was applied for simulation of pulsations in pressure, discharge, and total energy propagating along the flow conduit of the hydraulic power plant. Simulation results are in qualitative and quantitative agreement with experiment. The influence of key physical and numerical parameters like discharge, cavitation number, penstock length, time step, and vapor density on simulation results was studied.

  5. Characterization of fracture reservoirs using static and dynamic data: From sonic and 3D seismic to permeability distribution

    SciTech Connect

    Parra, J.O.; Hackett, C.L.; Brown, R.L.; Collier, H.A.; Datta-Gupta, A.

    1998-10-01

    To characterize the Buena Vista Hills field, the authors have implemented methods of modeling, processing and interpretation. The modeling methods are based on deterministic and stochastic solutions. Deterministic solutions were developed in Phase 1 and applied in Phase 2 to simulate acoustic responses of laminated reservoirs. Specifically, the simulations were aimed at implementing processing techniques to correct P-wave and S-wave velocity logs for scattering effects caused by thin layering. The authors are also including a summary of the theory and the processing steps of this new method for predicting intrinsic dispersion and attenuation in Section 2. Since the objective for correcting velocity scattering effects is to predict intrinsic dispersion from velocity data, they are presenting an application to illustrate how to relate permeability anisotropy with intrinsic dispersion. Also, the theoretical solution for calculating full waveform dipole sonic that was developed in Phase 1 was applied to simulate dipole responses at different azimuthal source orientations. The results will be used to interpret the effects of anisotropy associated with the presence of vertical fractures at Buena Vista Hills. The results of the integration of core, well logs, and geology of Buena Vista Hills is also given in Section 2. The results of this integration will be considered as the input model for the inversion technique for processing production data. Section 3 summarizes accomplishments. In Section 4 the authors present a summary of the technology transfer and promotion efforts associated with this project. In the last section, they address the work to be done in the next six months and future work by applying the processing, modeling and inversion techniques developed in Phases 1 and 2 of this project.

  6. 3D simulations of young core-collapse supernova remnants undergoing efficient particle acceleration

    NASA Astrophysics Data System (ADS)

    Ferrand, Gilles; Safi-Harb, Samar

    2016-06-01

    Within our Galaxy, supernova remnants are believed to be the major sources of cosmic rays up to the 'knee'. However important questions remain regarding the share of the hadronic and leptonic components, and the fraction of the supernova energy channelled into these components. We address such question by the means of numerical simulations that combine a hydrodynamic treatment of the shock wave with a kinetic treatment of particle acceleration. Performing 3D simulations allows us to produce synthetic projected maps and spectra of the thermal and non-thermal emission, that can be compared with multi-wavelength observations (in radio, X-rays, and γ-rays). Supernovae come in different types, and although their energy budget is of the same order, their remnants have different properties, and so may contribute in different ways to the pool of Galactic cosmic-rays. Our first simulations were focused on thermonuclear supernovae, like Tycho's SNR, that usually occur in a mostly undisturbed medium. Here we present our 3D simulations of core-collapse supernovae, like the Cas A SNR, that occur in a more complex medium bearing the imprint of the wind of the progenitor star.

  7. Novel 3D/VR interactive environment for MD simulations, visualization and analysis.

    PubMed

    Doblack, Benjamin N; Allis, Tim; Dávila, Lilian P

    2014-12-18

    The increasing development of computing (hardware and software) in the last decades has impacted scientific research in many fields including materials science, biology, chemistry and physics among many others. A new computational system for the accurate and fast simulation and 3D/VR visualization of nanostructures is presented here, using the open-source molecular dynamics (MD) computer program LAMMPS. This alternative computational method uses modern graphics processors, NVIDIA CUDA technology and specialized scientific codes to overcome processing speed barriers common to traditional computing methods. In conjunction with a virtual reality system used to model materials, this enhancement allows the addition of accelerated MD simulation capability. The motivation is to provide a novel research environment which simultaneously allows visualization, simulation, modeling and analysis. The research goal is to investigate the structure and properties of inorganic nanostructures (e.g., silica glass nanosprings) under different conditions using this innovative computational system. The work presented outlines a description of the 3D/VR Visualization System and basic components, an overview of important considerations such as the physical environment, details on the setup and use of the novel system, a general procedure for the accelerated MD enhancement, technical information, and relevant remarks. The impact of this work is the creation of a unique computational system combining nanoscale materials simulation, visualization and interactivity in a virtual environment, which is both a research and teaching instrument at UC Merced.

  8. Magnetospheric Magnetic Reconnection with Southward IMF by a 3D EMPM Simulation

    NASA Technical Reports Server (NTRS)

    Nishikawa, K.-I.; Yan, X. Y.; Cai, D. S.; Lembege, B.

    2004-01-01

    We report our new simulation results on magnetospheric magnetic reconnection with southward IMF using a 3D EMPM model, with greater resolution and more particles using the parallelized 3D HPF TRISTAN code on VPP5000 supercomputer. Main parameters used in the new simulation are: domain size is 215 x 145 x 145, grid size = 0.5 Earth radius, initial particle number is 16 per cell, the IMF is southward. Arrival of southward IMF will cause reconnection in the magnetopause, thus allowing particles to enter into the inner magnetosphere. Sunward and tailward high particle flow are observed by satellites, and these phenomena are also observed in the simulation near the neutral line (X line) of the near-Earth magnetotail. This high particle flow goes along with the reconnected island. The magnetic reconnection process contributes to direct plasma entry between the magnetosheath to the inner magnetosphere and plasma sheet, in which the entry process eats the magnetosheath plasma to plasma sheet temperatures. We investigate magnetic, electric fields, density, and current during this magnetic reconnection with southward IMF. Further investigation with this simulation will provide insight into unsolved problems, such as the triggering of storms and substorms, and the storm-substorm relationship. New results will be presented at the meeting.

  9. Novel 3D/VR Interactive Environment for MD Simulations, Visualization and Analysis

    PubMed Central

    Doblack, Benjamin N.; Allis, Tim; Dávila, Lilian P.

    2014-01-01

    The increasing development of computing (hardware and software) in the last decades has impacted scientific research in many fields including materials science, biology, chemistry and physics among many others. A new computational system for the accurate and fast simulation and 3D/VR visualization of nanostructures is presented here, using the open-source molecular dynamics (MD) computer program LAMMPS. This alternative computational method uses modern graphics processors, NVIDIA CUDA technology and specialized scientific codes to overcome processing speed barriers common to traditional computing methods. In conjunction with a virtual reality system used to model materials, this enhancement allows the addition of accelerated MD simulation capability. The motivation is to provide a novel research environment which simultaneously allows visualization, simulation, modeling and analysis. The research goal is to investigate the structure and properties of inorganic nanostructures (e.g., silica glass nanosprings) under different conditions using this innovative computational system. The work presented outlines a description of the 3D/VR Visualization System and basic components, an overview of important considerations such as the physical environment, details on the setup and use of the novel system, a general procedure for the accelerated MD enhancement, technical information, and relevant remarks. The impact of this work is the creation of a unique computational system combining nanoscale materials simulation, visualization and interactivity in a virtual environment, which is both a research and teaching instrument at UC Merced. PMID:25549300

  10. Using microstructure observations to quantify fracture properties and improve reservoir simulations. Final report, September 1998

    SciTech Connect

    Laubach, S.E.; Marrett, R.; Rossen, W.; Olson, J.; Lake, L.; Ortega, O.; Gu, Y.; Reed, R.

    1999-01-01

    The research for this project provides new technology to understand and successfully characterize, predict, and simulate reservoir-scale fractures. Such fractures have worldwide importance because of their influence on successful extraction of resources. The scope of this project includes creation and testing of new methods to measure, interpret, and simulate reservoir fractures that overcome the challenge of inadequate sampling. The key to these methods is the use of microstructures as guides to the attributes of the large fractures that control reservoir behavior. One accomplishment of the project research is a demonstration that these microstructures can be reliably and inexpensively sampled. Specific goals of this project were to: create and test new methods of measuring attributes of reservoir-scale fractures, particularly as fluid conduits, and test the methods on samples from reservoirs; extrapolate structural attributes to the reservoir scale through rigorous mathematical techniques and help build accurate and useful 3-D models of the interwell region; and design new ways to incorporate geological and geophysical information into reservoir simulation and verify the accuracy by comparison with production data. New analytical methods developed in the project are leading to a more realistic characterization of fractured reservoir rocks. Testing diagnostic and predictive approaches was an integral part of the research, and several tests were successfully completed.

  11. Nanoelectronic Modeling (NEMO): Moving from commercial grade 1-D simulation to prototype 3-D simulation

    NASA Astrophysics Data System (ADS)

    Klimeck, Gerhard

    2001-03-01

    The quantum mechanical functionality of commercially pursued heterostructure devices such as resonant tunneling diodes (RTDs), quantum well infrared photodetectors, and quantum well lasers are enabled by material variations on an atomic scale. The creation of these heterostructure devices is realized in a vast design space of material compositions, layer thicknesses and doping profiles. The full experimental exploration of this design space is unfeasible and a reliable design tool is needed. The Nanoelectronic Modeling tool (NEMO) is one of the first commercial grade attempts for such a modeling tool. NEMO was developed as a general-purpose quantum mechanics-based 1-D device design and analysis tool from 1993-97 by the Central Research Laboratory of Texas Instruments (later Raytheon Systems). NEMO enables(R. Lake, G. Klimeck, R. C. Bowen, and D. Jovanovic, J. Appl. Phys. 81), 7845 (1997). the fundamentally sound inclusion of the required(G. Klimeck et al.), in the 1997 55th Annual Device Research Conference Digest, (IEEE, NJ, 1997), p. 92^,(R. C. Bowen et al.), J. Appl. Phys 81, 3207 (1997). physics: bandstructure, scattering, and charge self-consistency based on the non-equilibrium Green function approach. A new class of devices which require full 3-D quantum mechanics based models is starting to emerge: quantum dots, or in general semiconductor based deca-nano devices. We are currently building a 3-D modeling tool based on NEMO to include the important physics to understand electronic stated in such superscaled structures. This presentation will overview various facets of the NEMO 1-D tool such electron transport physics in RTDs, numerical technology, software engineering and graphical user interface. The lessons learned from that work are now entering the 3D>NEMO 3-D development and first results using the NEMO 3-D prototype will be shown. More information about

  12. Recent Developments in the VISRAD 3-D Target Design and Radiation Simulation Code

    NASA Astrophysics Data System (ADS)

    Macfarlane, Joseph; Woodruff, P.; Golovkin, I.

    2011-10-01

    The 3-D view factor code VISRAD is widely used in designing HEDP experiments at major laser and pulsed-power facilities, including NIF, OMEGA, OMEGA-EP, ORION, Z, and PLX. It simulates target designs by generating a 3-D grid of surface elements, utilizing a variety of 3-D primitives and surface removal algorithms, and can be used to compute the radiation flux throughout the surface element grid by computing element-to-element view factors and solving power balance equations. Target set-up and beam pointing are facilitated by allowing users to specify positions and angular orientations using a variety of coordinates systems (e . g . , that of any laser beam, target component, or diagnostic port). Analytic modeling for laser beam spatial profiles for OMEGA DPPs and NIF CPPs is used to compute laser intensity profiles throughout the grid of surface elements. VISRAD includes a variety of user-friendly graphics for setting up targets and displaying results, can readily display views from any point in space, and can be used to generate image sequences for animations. We will discuss recent improvements to the software package and plans for future developments.

  13. 2-D/3-D ECE imaging data for validation of turbulence simulations

    NASA Astrophysics Data System (ADS)

    Choi, Minjun; Lee, Jaehyun; Yun, Gunsu; Lee, Woochang; Park, Hyeon K.; Park, Young-Seok; Sabbagh, Steve A.; Wang, Weixing; Luhmann, Neville C., Jr.

    2015-11-01

    The 2-D/3-D KSTAR ECEI diagnostic can provide a local 2-D/3-D measurement of ECE intensity. Application of spectral analysis techniques to the ECEI data allows local estimation of frequency spectra S (f) , wavenumber spectra S (k) , wavernumber and frequency spectra S (k , f) , and bispectra b (f1 ,f2) of ECE intensity over the 2-D/3-D space, which can be used to validate turbulence simulations. However, the minimum detectable fluctuation amplitude and the maximum detectable wavenumber are limited by the temporal and spatial resolutions of the diagnostic system, respectively. Also, the finite measurement area of the diagnostic channel could introduce uncertainty in the spectra estimation. The limitations and accuracy of the ECEI estimated spectra have been tested by a synthetic ECEI diagnostic with the model and/or fluctuations calculated by GTS. Supported by the NRF of Korea under Contract No. NRF-2014M1A7A1A03029881 and NRF-2014M1A7A1A03029865 and by U.S. DOE grant DE-FG02-99ER54524.

  14. SVD-GFD scheme to simulate complex moving body problems in 3D space

    NASA Astrophysics Data System (ADS)

    Wang, X. Y.; Yu, P.; Yeo, K. S.; Khoo, B. C.

    2010-03-01

    The present paper presents a hybrid meshfree-and-Cartesian grid method for simulating moving body incompressible viscous flow problems in 3D space. The method combines the merits of cost-efficient and accurate conventional finite difference approximations on Cartesian grids with the geometric freedom of generalized finite difference (GFD) approximations on meshfree grids. Error minimization in GFD is carried out by singular value decomposition (SVD). The Arbitrary Lagrangian-Eulerian (ALE) form of the Navier-Stokes equations on convecting nodes is integrated by a fractional-step projection method. The present hybrid grid method employs a relatively simple mode of nodal administration. Nevertheless, it has the geometrical flexibility of unstructured mesh-based finite-volume and finite element methods. Boundary conditions are precisely implemented on boundary nodes without interpolation. The present scheme is validated by a moving patch consistency test as well as against published results for 3D moving body problems. Finally, the method is applied on low-Reynolds number flapping wing applications, where large boundary motions are involved. The present study demonstrates the potential of the present hybrid meshfree-and-Cartesian grid scheme for solving complex moving body problems in 3D.

  15. ShrinkWrap: 3D model abstraction for remote sensing simulation

    SciTech Connect

    Pope, Paul A

    2009-01-01

    Remote sensing simulations often require the use of 3D models of objects of interest. There are a multitude of these models available from various commercial sources. There are image processing, computational, database storage, and . data access advantages to having a regularized, encapsulating, triangular mesh representing the surface of a 3D object model. However, this is usually not how these models are stored. They can have too much detail in some areas, and not enough detail in others. They can have a mix of planar geometric primitives (triangles, quadrilaterals, n-sided polygons) representing not only the surface of the model, but also interior features. And the exterior mesh is usually not regularized nor encapsulating. This paper presents a method called SHRlNKWRAP which can be used to process 3D object models to achieve output models having the aforementioned desirable traits. The method works by collapsing an encapsulating sphere, which has a regularized triangular mesh on its surface, onto the surface of the model. A GUI has been developed to make it easy to leverage this capability. The SHRlNKWRAP processing chain and use of the GUI are described and illustrated.

  16. Assessment of inlet efficiency through a 3D simulation: numerical and experimental comparison.

    PubMed

    Gómez, Manuel; Recasens, Joan; Russo, Beniamino; Martínez-Gomariz, Eduardo

    2016-10-01

    Inlet efficiency is a requirement for characterizing the flow transfers between surface and sewer flow during rain events. The dual drainage approach is based on the joint analysis of both upper and lower drainage levels, and the flow transfer is one of the relevant elements to define properly this joint behaviour. This paper presents the results of an experimental and numerical investigation about the inlet efficiency definition. A full scale (1:1) test platform located in the Technical University of Catalonia (UPC) reproduces both the runoff process in streets and the water entering the inlet. Data from tests performed on this platform allow the inlet efficiency to be estimated as a function of significant hydraulic and geometrical parameters. A reproduction of these tests through a numerical three-dimensional code (Flow-3D) has been carried out simulating this type of flow by solving the RANS equations. The aim of the work was to reproduce the hydraulic performance of a previously tested grated inlet under several flow and geometric conditions using Flow-3D as a virtual laboratory. This will allow inlet efficiencies to be obtained without previous experimental tests. Moreover, the 3D model allows a better understanding of the hydraulics of the flow interception and the flow patterns approaching the inlet.

  17. 3-D imaging and quantitative comparison of human dentitions and simulated bite marks.

    PubMed

    Blackwell, S A; Taylor, R V; Gordon, I; Ogleby, C L; Tanijiri, T; Yoshino, M; Donald, M R; Clement, J G

    2007-01-01

    This study presents a technique developed for 3-D imaging and quantitative comparison of human dentitions and simulated bite marks. A sample of 42 study models and the corresponding bites, made by the same subjects in acrylic dental wax, were digitised by laser scanning. This technique allows image comparison of a 3-D dentition with a 3-D bite mark, eliminating distortion due to perspective as experienced in conventional photography. Cartesian co-ordinates of a series of landmarks were used to describe the dentitions and bite marks, and a matrix was created to compare all possible combinations of matches and non-matches using cross-validation techniques. An algorithm, which estimated the probability of a dentition matching its corresponding bite mark, was developed. A receiver operating characteristic graph illustrated the relationship between values for specificity and sensitivity. This graph also showed for this sample that 15% of non-matches could not be distinguished from the true match, translating to a 15% probability of falsely convicting an innocent person.

  18. The application of seismic stratigraphic methods on exploration 3D seismic data to define a reservoir model in OPL 210, Deepwater Nigeria

    SciTech Connect

    Ragnhild, L.; Ventris, P.; Osahon, G.

    1995-08-01

    OPL 210 lies in deepwater on the northwestern flank of the Niger Delta. The partners in this block are Allied Energy and The Statoil and BP Alliance. The license has a 5 year initial exploration phase and carries a 2 well commitment. At present the database comprises a 1 x 1 km grid of 2D seismic across the block, and 450 sq. km of 3D in an area of special interest. A larger 3D survey is planned for 1995. Little is known about the reservoir in the deep water, but we expect our main target to be ponded slope and basin turbidites. As such the bulk of the shelf well data available has little or no relevance to the play type likely to be encountered. Prior to drilling, seismic stratigraphy has been one of several methods used to generate a consistent predictive reservoir model. The excellent quality and high resolution of the 3D data have allowed identification and detailed description of several distinctive seismic facies. These facies are described in terms of their internal geometries and stacking patterns. The geometries are then interpreted based on a knowledge of depositional processes from analog slope settings. This enables a predictive model to be constructed for the distribution of reservoir within the observed facies. These predictions will be tested by one of the first wells drilled in the Nigerian deepwater in mid 1995.

  19. pF3D Simulations of SBS and SRS in NIF Hohlraum Experiments

    NASA Astrophysics Data System (ADS)

    Langer, Steven; Strozzi, David; Amendt, Peter; Chapman, Thomas; Hopkins, Laura; Kritcher, Andrea; Sepke, Scott

    2016-10-01

    We present simulations of stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS) for NIF experiments using high foot pulses in cylindrical hohlraums and for low foot pulses in rugby-shaped hohlraums. We use pF3D, a massively-parallel, paraxial-envelope laser plasma interaction code, with plasma profiles obtained from the radiation-hydrodynamics codes Lasnex and HYDRA. We compare the simulations to experimental data for SBS and SRS power and spectrum. We also show simulated SRS and SBS intensities at the target chamber wall and report the fraction of the backscattered light that passes through and misses the lenses. Work performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344. Release number LLNL-ABS-697482.

  20. M3D-K simulations of sawteeth and energetic particle transport in tokamak plasmas

    SciTech Connect

    Shen, Wei; Sheng, Zheng-Mao; Fu, G. Y.; Breslau, J. A.; Wang, Feng

    2014-09-15

    Nonlinear simulations of sawteeth and related energetic particle transport are carried out using the kinetic/magnetohydrodynamic (MHD) hybrid code M3D-K. MHD simulations show repeated sawtooth cycles for a model tokamak equilibrium. Furthermore, test particle simulations are carried out to study the energetic particle transport due to a sawtooth crash. The results show that energetic particles are redistributed radially in the plasma core, depending on pitch angle and energy. For trapped particles, the redistribution occurs for particle energy below a critical value in agreement with existing theories. For co-passing particles, the redistribution is strong with little dependence on particle energy. In contrast, the redistribution level of counter-passing particles decreases with increasing particle energy.

  1. 3D MHD Simulations of accreting neutron stars: evidence of QPO emission from the surface

    SciTech Connect

    Bachetti, Matteo; Burderi, Luciano; Romanova, Marina M.; Kulkarni, Akshay; Salvo, Tiziana di

    2010-07-15

    3D Magnetohydrodynamic simulations show that when matter accretes onto neutron stars, in particular if the misalignment angle is small, it does not constantly fall at a fixed spot. Instead, the location at which matter reaches the star moves. These moving hot spots can be produced both during stable accretion, where matter falls near the magnetic poles of the star, and unstable accretion, characterized by the presence of several tongues of matter which fall on the star near the equator, due to Rayleigh-Taylor instabilities. Precise modeling with Monte Carlo simulations shows that those movements could be observed as high frequency Quasi Periodic Oscillations. We performed a number of new simulation runs with a much wider set of parameters, focusing on neutron stars with a small misalignment angle. In most cases we observe oscillations whose frequency is correlated with the mass accretion rate M. Moreover, in some cases double QPOs appear, each of them showing the same correlation with M.

  2. 3D Integration of MEMS and IC: Design, Technology and Simulations

    NASA Astrophysics Data System (ADS)

    Taklo, Maaike M. V.; Schjølberg-Henriksen, Kari; Lietaer, Nicolas; Prainsack, Josef; Elfving, Anders; Weber, Josef; Klein, Matthias; Schneider, Peter; Reitz, Sven

    A 3D integrated silicon stack consisting of two MEMS devices and two IC devices is presented. The MEMS devices are a pressure sensor and a bulk acoustic resonator (BAR). The stack was constructed for a tire pressure monitoring system (TPMS) which was one out of three demonstrators for an EU funded project called e-CUBES. Thermal simulations were performed to check the level of thermo-mechanical stresses induced on the pressure sensor membrane during extreme environmental conditions. Additional simulations were made to calculate the exact temperature on the BAR device during operation as this was important for the operational frequency. This paper presents and discusses the technology choices made for the stacking of the pressure sensor and the BAR. Results are given from simulations, initial short-loop experiments and for the final stacking.

  3. Three-dimensional simulations of high-current beams in induction accelerators with WARP3d

    SciTech Connect

    Grote, D.P.; Friedman, A.; Haber, I.

    1995-09-01

    For many issues relevant to acceleration and propagation of heavy-ion beams for inertial confinement fusion, understanding the behavior of the beam requires the self-consistent inclusion of the self-fields of the beams in multiple dimensions. For these reasons, the three-dimensional simulation code WARP3d A.Friedman was developed. The code combines the particle-in-cell plasma simulation technique with a realistic description of the elements which make up an accelerator. In this paper, the general structure of the code is reviewed and details of two ongoing applications are presented along with a discussion of simulation techniques used. The most important results of this work are presented.

  4. Fully 3D Multiple Beam Dynamics Processes Simulation for the Fermilab Tevatron

    SciTech Connect

    Stern, E.; Amundson, J.; Spentzouris, P; Valishev, A.; /Fermilab

    2010-06-01

    The Fermilab Tevatron has been, until 2010, the premier high-energy physics collider in the world. The data collected over the last decade by high-energy physics experiments running at the Tevatron have been analyzed to make important measurements in fundamental areas such as B meson masses and flavor oscillation, searches for the Higgs boson, and supersymmetry. Collecting these data at the limits of detectability has required the Tevatron to operate reliably at high beam intensities to maximize the number of collisions to analyze. This impressive achievement has been assisted by the use of HPC resources and software provided through the SciDAC program. This paper describes the enhancements to the BeamBeam3d code to realistically simulate the Tevatron, the validation of these simulations, and the improvement in equipment reliability and personal safety achieved with the aid of simulations.

  5. Balloon Ascent: 3-D Simulation Tool for the Ascent and Float of High-Altitude Balloons

    NASA Technical Reports Server (NTRS)

    Farley, Rodger E.

    2005-01-01

    The BalloonAscent balloon flight simulation code represents a from-scratch development using Visual Basic 5 as the software platform. The simulation code is a transient analysis of balloon flight, predicting the skin and gas temperatures along with the 3-D position and velocity in a time and spatially varying environment. There are manual and automated controls for gas valving and the dropping of ballast. Also, there are many handy calculators, such as appropriate free lift, and steady-state thermal solutions with temperature gradients. The strength of this simulation model over others in the past is that the infrared environment is deterministic rather than guessed at. The ground temperature is specified along with the emissivity, which creates a ground level IR environment that is then partially absorbed as it travels upward through the atmosphere to the altitude of the balloon.

  6. 3-D Simulations of Plasma Wakefield Acceleration with Non-Idealized Plasmas and Beams

    SciTech Connect

    Deng, S.; Katsouleas, T.; Lee, S.; Muggli, P.; Mori, W.B.; Hemker, R.; Ren, C.; Huang, C.; Dodd, E.; Blue, B.E.; Clayton, C.E.; Joshi, C.; Wang, S.; Decker, F.J.; Hogan, M.J.; Iverson, R.H.; O'Connell, C.; Raimondi, P.; Walz, D.; /SLAC

    2005-09-27

    3-D Particle-in-cell OSIRIS simulations of the current E-162 Plasma Wakefield Accelerator Experiment are presented in which a number of non-ideal conditions are modeled simultaneously. These include tilts on the beam in both planes, asymmetric beam emittance, beam energy spread and plasma inhomogeneities both longitudinally and transverse to the beam axis. The relative importance of the non-ideal conditions is discussed and a worst case estimate of the effect of these on energy gain is obtained. The simulation output is then propagated through the downstream optics, drift spaces and apertures leading to the experimental diagnostics to provide insight into the differences between actual beam conditions and what is measured. The work represents a milestone in the level of detail of simulation comparisons to plasma experiments.

  7. Study of the internal magnetic field of Mercury through 3D hybrid simulations

    NASA Astrophysics Data System (ADS)

    Leclercq, Ludivine; Marcel Chanteur, Gerard; Modolo, Ronan; Leblanc, Francois; Schmidt, Carl; Langlais, Benoît; Thebault, Erwan

    2016-10-01

    In 1974, Mariner 10 discovered the intrinsic magnetic field of Mercury which interacts with the solar wind, leading to the formation of a magnetosphere. In spite of the recent MESSENGER observations, this magnetosphere remains quite unknown, especially in the Southern hemisphere. In order to improve our understanding of the Hermean magnetosphere, and to prepare the Bepi-Colombo mission (ESA/JAXA), we simulated the magnetized environment of Mercury using the model named LatHyS (LATMOS Hybrid Simulation). LatHyS is a 3D parallel multi-species hybrid code which has been applied to Mars, Titan and Ganymede, which has recently be improved by the implementation of a multi-grid method allowing to refine the spatial resolution near the planetary object (40 km in the case of Mercury). In order to investigate the Hermean environment, several hybrid simulations have been performed considering different internal field models, and results are compared with MESSENGER observations.

  8. 3-D Simulations Of AGN Feedback via Radiation and Radiation-driven Outflows

    NASA Astrophysics Data System (ADS)

    Kurosawa, Ryuichi; Proga, D.

    2009-01-01

    We present numerical studies of non-axisymmetric, time-dependent gas hydrodynamic in a relatively large scale ( 10 pc). We consider the gas under the influence of the gravity of a super massive black hole (SMBH) and the radiation produced by a radiatively efficient flow accreting onto the SMBH. We examine two cases: (1) the formation of an outflow from the accretion of the ambient gas without rotation and (2) that with rotation. Our 3-D simulations of a non-rotating gas show small yet noticeable non-axisymmetric small-scale features inside the outflow; however, the outflow as a whole and the inflow do not seem to suffer from any large-scale instability. In the rotating case, the non-axisymmetric features are very prominent, especially in the outflow which consists of many cold dense clouds entrained in a smoother hot component. The 3-D outflow becomes non-axisymmetric due to the shear and thermal instabilities. We find that gas rotation increases the outflow thermal energy flux, but it reduces the outflow mass and kinetic energy fluxes and the outflow collimation. The virial mass estimated from the kinematics of the cold clouds found in our 3-D simulations of rotating gas underestimates the actual mass used in the simulations by about 40%. Overall the large scale outflow significantly reduces the rate at which mass accretes onto the SMBH. This work was supported by NASA through grant HST-AR-11276 from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  9. RF study and 3-D simulations of a side-coupling thermionic RF-gun

    NASA Astrophysics Data System (ADS)

    Rimjaem, S.; Kusoljariyakul, K.; Thongbai, C.

    2014-02-01

    A thermionic RF-gun for generating ultra-short electron bunches was optimized, developed and used as a source at a linac-based THz radiation research laboratory of the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The RF-gun is a π/2-mode standing wave structure, which consists of two S-band accelerating cells and a side-coupling cavity. The 2856 MHz RF wave is supplied from an S-band klystron to the gun through the waveguide input-port at the cylindrical wall of the second cell. A fraction of the RF power is coupled from the second cell to the first one via a side-coupling cavity. Both the waveguide input-port and the side-coupling cavity lead to an asymmetric geometry of the gun. RF properties and electromagnetic field distributions inside the RF-gun were studied and numerically simulated by using computer codes SUPERFISH 7.19 and CST Microwave Studio 2012©. RF characterizations and tunings of the RF-gun were performed to ensure the reliability of the gun operation. The results from 3D simulations and measurements are compared and discussed in this paper. The influence of asymmetric field distributions inside the RF-gun on the electron beam properties was investigated via 3D beam dynamics simulations. A change in the coupling-plane of the side-coupling cavity is suggested to improve the gun performance.

  10. 3D printing of tissue-simulating phantoms for calibration of biomedical optical devices

    NASA Astrophysics Data System (ADS)

    Zhao, Zuhua; Zhou, Ximing; Shen, Shuwei; Liu, Guangli; Yuan, Li; Meng, Yuquan; Lv, Xiang; Shao, Pengfei; Dong, Erbao; Xu, Ronald X.

    2016-10-01

    Clinical utility of many biomedical optical devices is limited by the lack of effective and traceable calibration methods. Optical phantoms that simulate biological tissues used for optical device calibration have been explored. However, these phantoms can hardly simulate both structural and optical properties of multi-layered biological tissue. To address this limitation, we develop a 3D printing production line that integrates spin coating, light-cured 3D printing and Fused Deposition Modeling (FDM) for freeform fabrication of optical phantoms with mechanical and optical heterogeneities. With the gel wax Polydimethylsiloxane (PDMS), and colorless light-curable ink as matrix materials, titanium dioxide (TiO2) powder as the scattering ingredient, graphite powder and black carbon as the absorption ingredient, a multilayer phantom with high-precision is fabricated. The absorption and scattering coefficients of each layer are measured by a double integrating sphere system. The results demonstrate that the system has the potential to fabricate reliable tissue-simulating phantoms to calibrate optical imaging devices.

  11. High-resolution 3D simulations of NIF ignition targets performed on Sequoia with HYDRA

    NASA Astrophysics Data System (ADS)

    Marinak, M. M.; Clark, D. S.; Jones, O. S.; Kerbel, G. D.; Sepke, S.; Patel, M. V.; Koning, J. M.; Schroeder, C. R.

    2015-11-01

    Developments in the multiphysics ICF code HYDRA enable it to perform large-scale simulations on the Sequoia machine at LLNL. With an aggregate computing power of 20 Petaflops, Sequoia offers an unprecedented capability to resolve the physical processes in NIF ignition targets for a more complete, consistent treatment of the sources of asymmetry. We describe modifications to HYDRA that enable it to scale to over one million processes on Sequoia. These include new options for replicating parts of the mesh over a subset of the processes, to avoid strong scaling limits. We consider results from a 3D full ignition capsule-only simulation performed using over one billion zones run on 262,000 processors which resolves surface perturbations through modes l = 200. We also report progress towards a high-resolution 3D integrated hohlraum simulation performed using 262,000 processors which resolves surface perturbations on the ignition capsule through modes l = 70. These aim for the most complete calculations yet of the interactions and overall impact of the various sources of asymmetry for NIF ignition targets. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

  12. Aeroacoustic Simulation of a Nose Landing Gear in an Open Jet Facility Using FUN3D

    NASA Technical Reports Server (NTRS)

    Vatsa, Veer N.; Lockhard, David P.; Khorrami, Mehdi R.; Carlson, Jan-Renee

    2012-01-01

    Numerical simulations have been performed for a partially-dressed, cavity-closed nose landing gear configuration that was tested in NASA Langley s closed-wall Basic Aerodynamic Research Tunnel (BART) and in the University of Florida s open-jet acoustic facility known as UFAFF. The unstructured-grid flow solver, FUN3D, developed at NASA Langley Research center is used to compute the unsteady flow field for this configuration. A hybrid Reynolds-averaged Navier-Stokes/large eddy simulation (RANS/LES) turbulence model is used for these computations. Time-averaged and instantaneous solutions compare favorably with the measured data. Unsteady flowfield data obtained from the FUN3D code are used as input to a Ffowcs Williams-Hawkings noise propagation code to compute the sound pressure levels at microphones placed in the farfield. Significant improvement in predicted noise levels is obtained when the flowfield data from the open jet UFAFF simulations is used as compared to the case using flowfield data from the closed-wall BART configuration.

  13. Aeroacoustic Simulation of Nose Landing Gear on Adaptive Unstructured Grids With FUN3D

    NASA Technical Reports Server (NTRS)

    Vatsa, Veer N.; Khorrami, Mehdi R.; Park, Michael A.; Lockhard, David P.

    2013-01-01

    Numerical simulations have been performed for a partially-dressed, cavity-closed nose landing gear configuration that was tested in NASA Langley s closed-wall Basic Aerodynamic Research Tunnel (BART) and in the University of Florida's open-jet acoustic facility known as the UFAFF. The unstructured-grid flow solver FUN3D, developed at NASA Langley Research center, is used to compute the unsteady flow field for this configuration. Starting with a coarse grid, a series of successively finer grids were generated using the adaptive gridding methodology available in the FUN3D code. A hybrid Reynolds-averaged Navier-Stokes/large eddy simulation (RANS/LES) turbulence model is used for these computations. Time-averaged and instantaneous solutions obtained on these grids are compared with the measured data. In general, the correlation with the experimental data improves with grid refinement. A similar trend is observed for sound pressure levels obtained by using these CFD solutions as input to a FfowcsWilliams-Hawkings noise propagation code to compute the farfield noise levels. In general, the numerical solutions obtained on adapted grids compare well with the hand-tuned enriched fine grid solutions and experimental data. In addition, the grid adaption strategy discussed here simplifies the grid generation process, and results in improved computational efficiency of CFD simulations.

  14. 3D numerical simulation of the evolutionary process of aeolian downsized crescent-shaped dunes

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaosi; Zhang, Yang; Wang, Yuan; Li, Min

    2016-06-01

    A dune constitutive model was coupled with a large eddy simulation (LES) with the Smagorinsky subgrid-scale (SGS) model to accurately describe the evolutionary process of dunes from the macroscopic perspective of morphological dynamics. A 3D numerical simulation of the evolution of aeolian downsized crescent-shaped dunes was then performed. The evolution of the 3D structure of Gaussian-shaped dunes was simulated under the influence of gravity modulation, which was the same with the vertical oscillation of the sand bed to adjust the threshold of sand grain liftoff in wind tunnel experiments under the same wind speed. The influence of gravity modulation intensity on the characteristic scale parameter of the dune was discussed. Results indicated that the crescent shape of the dune was reproduced with the action of gravity during regulation of the saturation of wind-sand flow at specific times. The crescent shape was not dynamically maintained as time passed, and the dunes dwindled until they reached final decomposition because of wind erosion. The height of the dunes decreased over time, and the height-time curve converged as the intensity of modulation increased linearly. The results qualitatively agreed with those obtained from wind tunnel experiments.

  15. BioFVM: an efficient, parallelized diffusive transport solver for 3-D biological simulations

    PubMed Central

    Ghaffarizadeh, Ahmadreza; Friedman, Samuel H.; Macklin, Paul

    2016-01-01

    Motivation: Computational models of multicellular systems require solving systems of PDEs for release, uptake, decay and diffusion of multiple substrates in 3D, particularly when incorporating the impact of drugs, growth substrates and signaling factors on cell receptors and subcellular systems biology. Results: We introduce BioFVM, a diffusive transport solver tailored to biological problems. BioFVM can simulate release and uptake of many substrates by cell and bulk sources, diffusion and decay in large 3D domains. It has been parallelized with OpenMP, allowing efficient simulations on desktop workstations or single supercomputer nodes. The code is stable even for large time steps, with linear computational cost scalings. Solutions are first-order accurate in time and second-order accurate in space. The code can be run by itself or as part of a larger simulator. Availability and implementation: BioFVM is written in C ++ with parallelization in OpenMP. It is maintained and available for download at http://BioFVM.MathCancer.org and http://BioFVM.sf.net under the Apache License (v2.0). Contact: paul.macklin@usc.edu. Supplementary information: Supplementary data are available at Bioinformatics online. PMID:26656933

  16. A 3D simulation of the early winter distribution of reactive chlorine in the north polar vortex

    NASA Technical Reports Server (NTRS)

    Douglass, A.; Rood, R.; Waters, J.; Froidevaux, L.; Read, W.; Elson, L.; Geller, M.; Chi, Y.; Cerniglia, M.; Steenrod, S.

    1993-01-01

    Early in December 1991, high values of ClO are seen by the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite at latitudes south of areas of temperatures cold enough to form polar stratospheric clouds (PSCs). A 3D simulation shows that the heterogeneous conversion of chlorine reservoirs to reactive chlorine on the surfaces of PSCs (processing) takes place at high latitudes. Often the processed air must be transported to lower latitudes, where the reactive chlorine is photochemically converted to ClO, to be observed by MLS. In this simulation, one incidence of cold temperatures is associated with an anticyclone, and a second with a cyclone. The transport of processed air associated with the anticyclone is marked by shearing; a decrease in the maximum of the processed air is accompanied by growth of the area influenced by the processing. In contrast, the air processed in the cyclonic event spreads more slowly. This shows that transport and shearing is a crucial element to the evolution of reactive chlorine associated with a processing event. In particular, transport and shearing, as well as photochemical processes, can cause variations in observed ClO.

  17. Visualization of reservoir simulation data with an immersive virtual reality system

    SciTech Connect

    Williams, B.K.

    1996-10-01

    This paper discusses an investigation into the use of an immersive virtual reality (VR) system to visualize reservoir simulation output data. The hardware and software configurations of the test-immersive VR system are described and compared to a nonimmersive VR system and to an existing workstation screen-based visualization system. The structure of 3D reservoir simulation data and the actions to be performed on the data within the VR system are discussed. The subjective results of the investigation are then presented, followed by a discussion of possible future work.

  18. Numerical simulation of a combined oxidation ditch flow using 3D k-epsilon turbulence model.

    PubMed

    Luo, Lin; Li, Wei-min; Deng, Yong-sen; Wang, Tao

    2005-01-01

    The standard three dimensional(3D) k-epsilon turbulence model was applied to simulate the flow field of a small scale combined oxidation ditch. The moving mesh approach was used to model the rotor of the ditch. Comparison of the computed and the measured data is acceptable. A vertical reverse flow zone in the ditch was found, and it played a very important role in the ditch flow behavior. The flow pattern in the ditch is discussed in detail, and approaches are suggested to improve the hydrodynamic performance in the ditch.

  19. 3-D Hybrid Simulation of Quasi-Parallel Bow Shock and Its Effects on the Magnetosphere

    SciTech Connect

    Lin, Y.; Wang, X.Y.

    2005-08-01

    A three-dimensional (3-D) global-scale hybrid simulation is carried out for the structure of the quasi-parallel bow shock, in particular the foreshock waves and pressure pulses. The wave evolution and interaction with the dayside magnetosphere are discussed. It is shown that diamagnetic cavities are generated in the turbulent foreshock due to the ion beam plasma interaction, and these compressional pulses lead to strong surface perturbations at the magnetopause and Alfven waves/field line resonance in the magnetosphere.

  20. A uniform input data convention for the CALL 3-D crash victim simulation

    NASA Astrophysics Data System (ADS)

    Shaibani, S. J.

    1982-07-01

    Logical schemes for the labelling of planes (cards D) and functions (cards E) in the input decks used for the Calspan 3-D Crash Victim Simulation (CVS) program are proposed. One benefit of introducing such a standardized format for these inputs would be to facilitate greatly the interchange of data for different vehicles. A further advantage would be that the table of allowed contacts (cards F) could remain largely unaltered. It is hoped that the uniformity of the convention described by these schemes would help to promote the exchange of readily usable data between CVS users.

  1. 3D Simulations for a Micron-Scale, Dielectric-Based Acceleration Experiment

    SciTech Connect

    Yoder, R. B.; Travish, G.; Xu Jin; Rosenzweig, J. B.

    2009-01-22

    An experimental program to demonstrate a dielectric, slab-symmetric accelerator structure has been underway for the past two years. These resonant devices are driven by a side-coupled 800-nm laser and can be configured to maintain the field profile necessary for synchronous acceleration and focusing of relativistic or nonrelativistic particles. We present 3D simulations of various versions of the structure geometry, including a metal-walled structure relevant to ongoing cold tests on resonant properties, and an all-dielectric structure to be constructed for a proof-of-principle acceleration experiment.

  2. 3D Simulation of an Audible Ultrasonic Electrolarynx Using Difference Waves

    PubMed Central

    Mills, Patrick; Zara, Jason

    2014-01-01

    A total laryngectomy removes the vocal folds which are fundamental in forming voiced sounds that make speech possible. Although implanted prosthetics are commonly used in developed countries, simple handheld vibrating electrolarynxes are still common worldwide. These devices are easy to use but suffer from many drawbacks including dedication of a hand, mechanical sounding voice, and sound leakage. To address some of these drawbacks, we introduce a novel electrolarynx that uses vibro-acoustic interference of dual ultrasonic waves to generate an audible fundamental frequency. A 3D simulation of the principles of the device is presented in this paper. PMID:25401965

  3. Parallel implementation of the FETI-DPEM algorithm for general 3D EM simulations

    NASA Astrophysics Data System (ADS)

    Li, Yu-Jia; Jin, Jian-Ming

    2009-05-01

    A parallel implementation of the electromagnetic dual-primal finite element tearing and interconnecting algorithm (FETI-DPEM) is designed for general three-dimensional (3D) electromagnetic large-scale simulations. As a domain decomposition implementation of the finite element method, the FETI-DPEM algorithm provides fully decoupled subdomain problems and an excellent numerical scalability, and thus is well suited for parallel computation. The parallel implementation of the FETI-DPEM algorithm on a distributed-memory system using the message passing interface (MPI) is discussed in detail along with a few practical guidelines obtained from numerical experiments. Numerical examples are provided to demonstrate the efficiency of the parallel implementation.

  4. 3D Flow Simulation Using Lattice Boltzmann Method on Real Carbonate Core-Plug Samples

    NASA Astrophysics Data System (ADS)

    Islam, A.; Faisal, T. F.; Chevalier, S.; Jouini, M. S.; Jouiad, M.; Sassi, M.

    2014-12-01

    Digital Rock Physics (DRP) is a novel technology that could be used to generate accurate, fast and cost effective special core analysis (SCAL) properties to support reservoir characterization and simulation tools. This work focuses on running numerical simulations using the Lattice Boltzmann algorithm on reconstructed volume from microCT images of carbonate core-plug samples at different resolutions. The porous media was first reconstructed from the retrieved image slices. Then the open-source software, Palabos was used to run the Lattice Boltzmann algorithm to simulate single phase flow in the medium and determine the permeability. The results were analyzed according to the resolutions of the original microCT images and the scale of the micro-plug.

  5. Exploratory Analysis Of The 3D Cloud Resolving Model Simulations of TOGA COARE: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Mendes, S.; Bretherton, C.

    2007-12-01

    Global climate model studies suggest that cumulus momentum transport (CMT) in tropical oceanic convective cloud systems plays a significant role in the tropical mean circulation and transient variability. CMT is difficult to measure directly and can depend on the detailed structure and organization of the convection. Yet there have been comparatively few evaluations of CMT parameterizations and the assumptions underlying them using 3D cloud resolving model (CRM) simulations. We have analyzed CMT in a four month 3D 64x64x64 gridpoint CRM simulation of TOGA COARE with 1 km horizontal resolution. An additional 256x256x64 large-domain simulation was performed for a 10 day subperiod with strong convection combined with substantial mean vertical zonal wind shear, conditions favorably for strong CMT. Both simulations were identically forced with prescribed vertical motion, horizontal temperature and moisture advection, and relaxation of the domain-mean wind profile to observations on a one-hour timescale. Both were initialized with small amplitude white noise, but spun up realistic convection in less than a day. The domain-mean CMT in the small and large domain simulations for the 10-day common simulation period was compared. The two simulations showed remarkably similar CMT profiles on daily-mean timescales, suggesting that mesoscale contributions to CMT of scales greater than 64 km were small. The skill of a downgradient mixing-length parameterization CMT = Mc*L*DU/Dz was also tested. Here , Mc is convective mass flux, dU/dz is mean vertical shear, and L is a mixing length for updraft zonal velocity perturbations associated with entrainment and horizontal pressure gradient accelerations. This was done by regressing CMT at each height was regressed against Mc*DU/Dz at the same height across all 3D model snapshots over the 10 days. The correlation coefficient describes the accuracy of this downgradient parameterization, and L was calculated as the regression slope. In the

  6. Characterization of fracture reservoirs using static and dynamic data: From sonic and 3D seismic to permeability distribution. Annual report, March 1, 1996--February 28, 1997

    SciTech Connect

    Parra, J.O.; Collier, H.A.; Owen, T.E.

    1997-06-01

    In low porosity, low permeability zones, natural fractures are the primary source of permeability which affect both production and injection of fluids. The open fractures do not contribute much to porosity, but they provide an increased drainage network to any porosity. They also may connect the borehole to remote zones of better reservoir characteristics. An important approach to characterizing the fracture orientation and fracture permeability of reservoir formations is one based on the effects of such conditions on the propagation of acoustic and seismic waves in the rock. The project is a study directed toward the evaluation of acoustic logging and 3D-seismic measurement techniques as well as fluid flow and transport methods for mapping permeability anisotropy and other petrophysical parameters for the understanding of the reservoir fracture systems and associated fluid dynamics. The principal application of these measurement techniques and methods is to identify and investigate the propagation characteristics of acoustic and seismic waves in the Twin Creek hydrocarbon reservoir owned by Union Pacific Resources (UPR) and to characterize the fracture permeability distribution using production data. This site is located in the overthrust area of Utah and Wyoming. UPR drilled six horizontal wells, and presently UPR has two rigs running with many established drill hole locations. In addition, there are numerous vertical wells that exist in the area as well as 3D seismic surveys. Each horizontal well contains full FMS logs and MWD logs, gamma logs, etc.

  7. Advanced Reservoir Characterization and Development through High-Resolution 3C3D Seismic and Horizontal Drilling: Eva South Marrow Sand Unit, Texas County, Oklahoma

    SciTech Connect

    Wheeler,David M.; Miller, William A.; Wilson, Travis C.

    2002-03-11

    The Eva South Morrow Sand Unit is located in western Texas County, Oklahoma. The field produces from an upper Morrow sandstone, termed the Eva sandstone, deposited in a transgressive valley-fill sequence. The field is defined as a combination structural stratigraphic trap; the reservoir lies in a convex up -dip bend in the valley and is truncated on the west side by the Teepee Creek fault. Although the field has been a successful waterflood since 1993, reservoir heterogeneity and compartmentalization has impeded overall sweep efficiency. A 4.25 square mile high-resolution, three component three-dimensional (3C3D) seismic survey was acquired in order to improve reservoir characterization and pinpoint the optimal location of a new horizontal producing well, the ESU 13-H.

  8. Terascale direct numerical simulations of turbulent combustion using S3D

    NASA Astrophysics Data System (ADS)

    Chen, J. H.; Choudhary, A.; de Supinski, B.; DeVries, M.; Hawkes, E. R.; Klasky, S.; Liao, W. K.; Ma, K. L.; Mellor-Crummey, J.; Podhorszki, N.; Sankaran, R.; Shende, S.; Yoo, C. S.

    2009-01-01

    Computational science is paramount to the understanding of underlying processes in internal combustion engines of the future that will utilize non-petroleum-based alternative fuels, including carbon-neutral biofuels, and burn in new combustion regimes that will attain high efficiency while minimizing emissions of particulates and nitrogen oxides. Next-generation engines will likely operate at higher pressures, with greater amounts of dilution and utilize alternative fuels that exhibit a wide range of chemical and physical properties. Therefore, there is a significant role for high-fidelity simulations, direct numerical simulations (DNS), specifically designed to capture key turbulence-chemistry interactions in these relatively uncharted combustion regimes, and in particular, that can discriminate the effects of differences in fuel properties. In DNS, all of the relevant turbulence and flame scales are resolved numerically using high-order accurate numerical algorithms. As a consequence terascale DNS are computationally intensive, require massive amounts of computing power and generate tens of terabytes of data. Recent results from terascale DNS of turbulent flames are presented here, illustrating its role in elucidating flame stabilization mechanisms in a lifted turbulent hydrogen/air jet flame in a hot air coflow, and the flame structure of a fuel-lean turbulent premixed jet flame. Computing at this scale requires close collaborations between computer and combustion scientists to provide optimized scaleable algorithms and software for terascale simulations, efficient collective parallel I/O, tools for volume visualization of multiscale, multivariate data and automating the combustion workflow. The enabling computer science, applied to combustion science, is also required in many other terascale physics and engineering simulations. In particular, performance monitoring is used to identify the performance of key kernels in the DNS code, S3D and especially memory

  9. Insights from 3D numerical simulations on the dynamics of the India-Asia collision zone

    NASA Astrophysics Data System (ADS)

    Pusok, A. E.; Kaus, B.; Popov, A.

    2013-12-01

    The dynamics of the India-Asia collision zone remains one of the most remarkable topics of the current research interest: the transition from subduction to collision and uplift, followed by the rise of the abnormally thick Tibetan plateau, and the deformation at its Eastern and Western syntaxes, are processes still not fully understood. Models that have addressed this topic include wholescale underthrusting of Indian lithospheric mantle under Tibet, distributed homogeneous shortening or the thin-sheet model, slip-line field model for lateral extrusion or lower crustal flow models for the exhumation of the Himalayan units and lateral spreading of the Tibetan plateau. Of these, the thin-sheet model has successfully illustrated some of the basic physics of continental collision and has the advantage of a 3D model being reduced to 2D, but one of its major shortcomings is that it cannot simultaneously represent channel flow and gravitational collapse of the mantle lithosphere, since these mechanisms require the lithosphere to interact with the underlying mantle, or to have a vertically non-homogeneous rheology. As a consequence, 3D models are emerging as powerful tools to understand the dynamics of coupled systems. However, because of yet recent developments and various complexities, the current 3D models simulating the dynamics of continent collision zones have relied on certain explicit assumptions, such as replacing part of the asthenosphere with various types of boundary conditions that mimic the effect of mantle flow, in order to focus on the lithospheric/crustal deformation. Here, we employ the parallel 3D code LaMEM (Lithosphere and Mantle Evolution Model), with a finite difference staggered grid solver, which is capable of simulating lithospheric deformation while simultaneously taking mantle flow and a free surface into account. We present qualitative results on lithospheric and upper-mantle scale simulations in which the Indian lithosphere is subducted and

  10. A 3-D nonisothermal flow simulation and pulling force model for injection pultrusion processes

    NASA Astrophysics Data System (ADS)

    Mustafa, Ibrahim

    1998-12-01

    Injected Pultrusion (IP) is an efficient way of producing high quality, low cost, high volume and constant cross-section polymeric composites. This process has been developed recently, and the efforts to optimize it are still underway. This work is related to the development of a 3-D non-isothermal flow model for the IP processes. The governing equations for transport of mass, momentum and, energy are formulated by using a local volume averaging approach, and the Finite Element/Control Volume method is used to solve the system of equations numerically. The chemical species balance equation is solved in the Lagrangian frame of reference whereas the energy equation is solved using Galerkin, SU (Streamline Upwind), and SUPG (Streamline Upwind Petrov Galerkin) approaches. By varying degrees of freedom and the flow rates of the resin, it is shown that at high Peclet numbers the SUPG formulation performs better than the SU and the Galerkin methods in all cases. The 3-D model predictions for degree of cure and temperature are compared with a one dimensional analytical solution and the results are found satisfactory. Moreover, by varying the Brinkman Number, it is shown that the effect of viscous dissipation is insignificant. The 3-D flow simulations have been carried out for both thin and thick parts and the results are compared with the 2-D model. It is shown that for thick parts 2-D simulations render erroneous results. The effect of changing permeability on the flow fronts is also addressed. The effect of increasing taper angle on the model prediction is also investigated. A parametric study is conducted to isolate optimum conditions for both isothermal and non-isothermal cases using a straight rectangular die and a die with a tapered inlet. Finally, a simple pulling force model is developed and the pulling force required to pull the carbon-epoxy fiber resin system is estimated for dies of varying tapered inlet.

  11. Representation of wells in numerical reservoir simulation

    SciTech Connect

    Ding, Y.; Renard, G.; Weill, L.

    1995-12-31

    In reservoir simulation, linear approximations are generally used for well modeling. However, this type of approximations can be inaccurate for fluid flow calculation in the vicinity of wells leading to incorrect well performance predictions. To overcome such problems, a new well representation has been proposed that uses a ``logarithmic`` type of approximation for vertical wells. In this paper, it is shown how the new well model can be easily implemented in existing simulator through the conventional PI. The relationship between wellbore pressure, wellblock pressure and flow rate is discussed in more detail, especially for the definition of wellblock pressure. Extension of the new approach to off-center wells and to flexible grids are both presented. Through this extension, the equivalence of various gridding techniques for the well model is emphasized. The key element is the accurate calculation of flow components in the vicinity of wells.

  12. ALE3D Simulation of Heating and Violence in a Fast Cookoff Experiment with LX-10

    SciTech Connect

    McClelland, M A; Maienschein, J L; Howard, W M; Nichols, A L; deHaven, M R; Strand, O T

    2006-06-26

    We performed a computational and experimental analysis of fast cookoff of LX-10 (94.7% HMX, 5.3% Viton A) confined in a 2 kbar steel tube with reinforced end caps. A Scaled-Thermal-Explosion-eXperiment (STEX) was completed in which three radiant heaters were used to heat the vessel until ignition, resulting in a moderately violent explosion after 20.4 minutes. Thermocouple measurements showed tube temperatures as high as 340 C at ignition and LX-10 surface temperatures as high as 279 C, which is near the melting point of HMX. Three micro-power radar systems were used to measure mean fragment velocities of 840 m/s. Photonics Doppler Velocimeters (PDVs) showed a rapid acceleration of fragments over 80 {micro}s. A one-dimensional ALE3D cookoff model at the vessel midplane was used to simulate the heating, thermal expansion, LX-10 decomposition composition, and closing of the gap between the HE (High Explosive) and vessel wall. Although the ALE3D simulation terminated before ignition, the model provided a good representation of heat transfer through the case and across the dynamic gap to the explosive.

  13. ALE3D Simulation and Measurement of Violence in a Fast Cookoff Experiment with LX-10

    SciTech Connect

    McClelland, M A; Maienschein, J L; Howard, W M; deHaven, M R

    2006-11-22

    We performed a computational and experimental analysis of fast cookoff of LX-10 (94.7% HMX, 5.3% Viton A) confined in a 2 kbar steel tube with reinforced end caps. A Scaled-Thermal-Explosion-eXperiment (STEX) was completed in which three radiant heaters were used to heat the vessel until ignition, resulting in a moderately violent explosion after 20.4 minutes. Thermocouple measurements showed tube temperatures as high as 340 C at ignition and LX-10 surface temperatures as high as 279 C, which is near the melting point of HMX. Three micro-power radar systems were used to measure mean fragment velocities of 840 m/s. Photonics Doppler Velocimeters (PDVs) showed a rapid acceleration of fragments over 80 {micro}s. A one-dimensional ALE3D cookoff model at the vessel midplane was used to simulate the heating, thermal expansion, LX-10 decomposition composition, and closing of the gap between the HE (High Explosive) and vessel wall. Although the ALE3D simulation terminated before ignition, the model provided a good representation of heat transfer through the case and across the dynamic gap to the explosive.

  14. Simulation of metal forming processes with a 3D adaptive remeshing procedure

    NASA Astrophysics Data System (ADS)

    Zeramdini, Bessam; Robert, Camille; Germain, Guenael; Pottier, Thomas

    2016-10-01

    In this paper, a fully adaptive 3D numerical methodology based on a tetrahedral element was proposed in order to improve the finite element simulation of any metal forming process. This automatic methodology was implemented in a computational platform which integrates a finite element solver, 3D mesh generation and a field transfer algorithm. The proposed remeshing method was developed in order to solve problems associated with the severe distortion of elements subject to large deformations, to concentrate the elements where the error is large and to coarsen the mesh where the error is small. This leads to a significant reduction in the computation times while maintaining simulation accuracy. In addition, in order to enhance the contact conditions, this method has been coupled with a specific operator to maintain the initial contact between the workpiece nodes and the rigid tool after each remeshing step. In this paper special attention is paid to the data transfer methods and the necessary adaptive remeshing steps are given. Finally, a numerical example is detailed to demonstrate the efficiency of the approach and to compare the results for the different field transfer strategies.

  15. 3D Global Two-Fluid Simulations of Turbulence in LAPD

    NASA Astrophysics Data System (ADS)

    Fisher, Dustin; Rogers, Barrett; Ricci, Paolo

    2012-10-01

    3D global two-fluid simulations are presented in an ongoing effort to identify and understand the physics of instabilities that arise in the Large Plasma Device (LAPD) at UCLA's Basic Science Facility. The LAPD, with its wide range of tunable parameters and device configurations, is ideally suited for studying space and laboratory plasmas. Moreover, the highly detailed and reproducible measurements of the LAPD lend themselves amicably to comparisons with simulations. Ongoing modeling is done using a modified version of the Global Braginskii Solver (GBS) [1] that models the plasma from source to edge region in a fully 3D two-fluid code. The reduced Braginskii equations are solved on a field-aligned grid using a finite difference method and 4th order Runge-Kutta time stepping and are parallelized on Dartmouth's Discovery cluster. Recent progress has been made to account for the thermionic cathode emission of fast electrons at the source, the axial dependence of the plasma source, and it is now possible to vary the potential on the front and side walls. Preliminary results, seen from the density and temperature profiles, show that the low frequency Kelvin Helmholtz instability still dominates the turbulence in the device.[4pt] [1] B. Rogers and P. Ricci. Phys. Rev. Lett. 104:225002, 2010

  16. Temporal 3D refined simulation of SF6 release in the ionosphere

    NASA Astrophysics Data System (ADS)

    Xu, Zheng-Wen; Zhao, Hai-Sheng; Wu, Jian; Feng, Jie; Xu, Bin; Zhang, Ya-Bin; Xue, Kun; Ma, Zheng-Zheng

    2017-04-01

    A number of significant studies have been dedicated to SF6 releases. However, given the complicated nature, the simulations provided at the design phases are still not consistent with those diagnosed in experiments. It is mainly because the actual conditions of experiments have not been fully introduced in the state-of-art models. A temporal 3D refined simulation model of SF6 release by a rocket payload is proposed in this paper. It first considers the release status (rocket attitude, velocity, etc.), release process (duration, injection velocity, the flux of the chemical release, etc.) and ambient neutral wind. This model is better than existing ones; the latter can only deal with release from a point source. The time-dependent drift of the released cloud, driven by the velocities of the rocket inertia and neutral wind, are calculated accurately. The non-uniform spherical structure of the electron density hole driven by the lasting release along the trajectory and the injection velocity are also described. The release flow field is calculated by using a new microcell method. The temporal 3D refined model proposed could be useful for improving the diagnosis and also helpful for the theory on chemical releases.

  17. Vortices and spirals at gap edges in 3D self-gravitating disk-planet simulations

    NASA Astrophysics Data System (ADS)

    Lin, M.

    2012-12-01

    Numerical simulations of global 3D self-gravitating protoplanetary disks with a gap opened by an embedded planet are presented. The simulations are customised to examine planetary gap stability. Previous results, obtained by Lin & Papaloizou from 2D disk models, are reproduced in 3D. These include (i) the development of vortices associated with local potential vorticity minima at gap edges and their merging on dynamical timescales in weakly self-gravitating disks, (ii) the increased number of vortices as the strength of self-gravity is increased and their resisted merging, and (iii) suppression of the vortex instability and development of global spiral arms associated with local potential vorticity maxima in massive disks. The vertical structure of these disturbances are examined. In terms of the relative density perturbation, the vortex disturbance has weak vertical dependence when self-gravity is neglected. Vortices become more stratified with increasing self-gravity. This effect is seen even when the unperturbed region around the planet's orbital radius has a Toomre stability parameter ~ 10. The spiral modes display significant vertical structure at the gap edge, with the midplane density enhancement being several times larger than that near the upper disk boundary. However, for both instabilities the vertical Mach number is small, and on average vertical motions near the gap edge do not dominate over horizontal motions.

  18. Surface rippling during solidification of binary polycrystalline alloy: Insights from 3-D phase-field simulations

    NASA Astrophysics Data System (ADS)

    Ankit, Kumar; Xing, Hui; Selzer, Michael; Nestler, Britta; Glicksman, Martin E.

    2017-01-01

    The mechanisms by which crystalline imperfections initiate breakdown of a planar front during directional solidification remain a topic of longstanding interest. Previous experimental findings show that the solid-liquid interface adjacent to a grain boundary provides a potential site where morphological instabilities initiate. However, interpretation of experimental data is difficult for complex 3-D diffusion fields that develop around grain multi-junctions and boundary ridges. We apply a phase-field approach to investigate factors that induce interfacial instabilities during directional solidification of a binary polycrystalline alloy. Using 2-D simulations, we establish the influence of solid-liquid interfacial energies on the spatial localization of initial interfacial perturbations. Based on parametric studies, we predict that grain misorientation and supersaturation in the melt provide major crystal growth factors determining solute segregation responsible for surface rippling. Subsequent breakdown of boundary ridges into periodic rows of hills, as simulated in 3-D, conform well with experiments. Finally, the significance of crystal misorientation relationships is elucidated in inducing spatial alignment of surface ripples.

  19. Comparing TID simulations using 3-D ray tracing and mirror reflection

    NASA Astrophysics Data System (ADS)

    Huang, X.; Reinisch, B. W.; Sales, G. S.; Paznukhov, V. V.; Galkin, I. A.

    2016-04-01

    Measuring the time variations of Doppler frequencies and angles of arrival (AoA) of ionospherically reflected HF waves has been proposed as a means of detecting the occurrence of traveling ionospheric disturbances (TIDs). Simulations are made using ray tracing through the International Reference Ionosphere (IRI) electron density model in an effort to reproduce measured signatures. The TID is represented by a wavelike perturbation of the 3-D electron density traveling horizontally in the ionosphere with an amplitude that varies sinusoidally with time. By judiciously selecting the TID parameters the ray tracing simulation reproduces the observed Doppler frequencies and AoAs. Ray tracing in a 3-D realistic ionosphere is, however, excessively time consuming considering the involved homing procedures. It is shown that a carefully selected reflecting corrugated mirror can reproduce the time variations of the AoA and Doppler frequency. The results from the ray tracing through the IRI model ionosphere and the mirror model reflections are compared to assess the applicability of the mirror-reflection model.

  20. 3D simulation of the image formation in soft x-ray microscopes.

    PubMed

    Selin, Mårten; Fogelqvist, Emelie; Holmberg, Anders; Guttmann, Peter; Vogt, Ulrich; Hertz, Hans M

    2014-12-15

    In water-window soft x-ray microscopy the studied object is typically larger than the depth of focus and the sample illumination is often partially coherent. This blurs out-of-focus features and may introduce considerable fringing. Understanding the influence of these phenomena on the image formation is therefore important when interpreting experimental data. Here we present a wave-propagation model operating in 3D for simulating the image formation of thick objects in partially coherent soft x-ray microscopes. The model is compared with present simulation methods as well as with experiments. The results show that our model predicts the image formation of transmission soft x-ray microscopes more accurately than previous models.

  1. Efficient physics-based predictive 3D image modeling and simulation of optical atmospheric refraction phenomena

    NASA Astrophysics Data System (ADS)

    Reinhardt, Colin N.; Hammel, Stephen M.; Tsintikidis, Dimitris

    2016-09-01

    We present some preliminary results and discussion of our ongoing effort to develop a prototype volumetric atmospheric optical refraction simulator which uses 3D nonlinear ray-tracing and state-of-art physics-based rendering techniques. The tool will allow simulation of optical curved-ray propagation through nonlinear refractivity gradient profiles in volumetric atmospheric participating media, and the generation of radiometrically accurate images of the resulting atmospheric refraction phenomena, including inferior and superior mirages, over-the-horizon viewing conditions, looming and sinking, towering and stooping of distant objects. The ability to accurately model and predict atmospheric optical refraction conditions and phenomena is important in both defense and commercial applications. Our nonlinear refractive ray-trace method is currently CPU-parallelized and is well-suited for GPU compute implementation.

  2. 3D nozzle flow simulations including state-to-state kinetics calculation

    NASA Astrophysics Data System (ADS)

    Cutrone, L.; Tuttafesta, M.; Capitelli, M.; Schettino, A.; Pascazio, G.; Colonna, G.

    2014-12-01

    In supersonic and hypersonic flows, thermal and chemical non-equilibrium is one of the fundamental aspects that must be taken into account for the accurate characterization of the plasma. In this paper, we present an optimized methodology to approach plasma numerical simulation by state-to-state kinetics calculations in a fully 3D Navier-Stokes CFD solver. Numerical simulations of an expanding flow are presented aimed at comparing the behavior of state-to-state chemical kinetics models with respect to the macroscopic thermochemical non-equilibrium models that are usually used in the numerical computation of high temperature hypersonic flows. The comparison is focused both on the differences in the numerical results and on the computational effort associated with each approach.

  3. Nonintrusive 3D reconstruction of human bone models to simulate their bio-mechanical response

    NASA Astrophysics Data System (ADS)

    Alexander, Tsouknidas; Antonis, Lontos; Savvas, Savvakis; Nikolaos, Michailidis

    2012-06-01

    3D finite element models representing functional parts of the human skeletal system, have been repeatedly introduced over the last years, to simulate biomechanical response of anatomical characteristics or investigate surgical treatment. The reconstruction of geometrically accurate FEM models, poses a significant challenge for engineers and physicians, as recent advances in tissue engineering dictate highly customized implants, while facilitating the production of alloplast materials that are employed to restore, replace or supplement the function of human tissue. The premises of every accurate reconstruction method, is to encapture the precise geometrical characteristics of the examined tissue and thus the selection of a sufficient imaging technique is of the up-most importance. This paper reviews existing and potential applications related to the current state-of-the-art of medical imaging and simulation techniques. The procedures are examined by introducing their concepts; strengths and limitations, while the authors also present part of their recent activities in these areas. [Figure not available: see fulltext.

  4. Use of albedo for neutron reflector regions in reactor core 3-D simulations

    NASA Astrophysics Data System (ADS)

    Mohanakrishnan, P.

    1989-10-01

    In this paper we present two new simplified schemes for the application of the albedo concept of replacing the reflector in 3-D reactor core simulations. Both involve the numerical derivation of albedoes from the fluxes at the core- (blanket-) reflector interface obtained from sample calculations including the reflector. Diffusion theory is used for core calculations in both cases. In the first scheme a new method for "diagonalising" the albedo matrix is demonstrated. This achieves easy applicability of the albedo parameters in core simulations of a fast breeder reactor core, resulting in significant savings in computing efforts. The second scheme, applied to light water reactors, achieves better accuracy in core periphery power predictions with the use of only uniform coarse meshes throughout the core and the numerically derived albedoes.

  5. M3D-K Simulations of Beam-Driven Fishbone Instability in DIIID

    NASA Astrophysics Data System (ADS)

    Fu, Guoyong; Tobias, Benjamin; van Zeeland, Michael

    2013-10-01

    Fishbone instability is often observed between sawtooth crashes in DIII-D with sufficient on-axis neutral beam power. In this work, hybrid simulations with the global kinetic/MHD hybrid code M3D-K have been carried out to investigate the linear stability and nonlinear dynamics of n = 1 mode with effects of energetic beam ions for parameters and profiles of a DIII-D discharge. The results show that the n = 1 internal kink mode is unstable in MHD limit. However, with kinetic effects of beam ions, a fishbone-like mode is found to be unstable with mode frequency about a few kHz, consistent with experimental observation. Nonlinear simulations are being performed to investigate mode saturation, frequency chirping as well as energetic particle transport. Numerical results will be compared with the experimental data from DIII-D.

  6. Activity of sulfate-reducing bacteria under simulated reservoir conditions

    SciTech Connect

    Rosnes, J.T.; Graue, A.; Lien, T. )

    1991-05-01

    This paper reports on sulfate-reducing bacteria (SRB) that have been isolated from hot oilfield waters from subsea oil reservoirs in the North Sea. Experiments with these bacteria in a reservoir simulator indicate that SRB may maintain their activity in the conditions found in most North Sea reservoirs and, if precautions are not taken, may contribute to souring of the oil and gas.

  7. Synthetic 3D modeling of active regions and simulation of their multi-wavelength emission

    NASA Astrophysics Data System (ADS)

    Nita, Gelu M.; Fleishman, Gregory; Kuznetsov, Alexey A.; Loukitcheva, Maria A.; Viall, Nicholeen M.; Klimchuk, James A.; Gary, Dale E.

    2015-04-01

    To facilitate the study of solar active regions, we have created a synthetic modeling framework that combines 3D magnetic structures obtained from magnetic extrapolations with simplified 1D thermal models of the chromosphere, transition region, and corona. To handle, visualize, and use such synthetic data cubes to compute multi-wavelength emission maps and compare them with observations, we have undertaken a major enhancement of our simulation tools, GX_Simulator (ftp://sohoftp.nascom.nasa.gov/solarsoft/packages/gx_simulator/), developed earlier for modeling emission from flaring loops. The greatly enhanced, object-based architecture, which now runs on Windows, Mac, and UNIX platform, offers important new capabilities that include the ability to either import 3D density and temperature distribution models, or to assign to each individual voxel numerically defined coronal or chromospheric temperature and densities, or coronal Differential Emission Measure distributions. Due to these new capabilities, the GX_Simulator can now apply parametric heating models involving average properties of the magnetic field lines crossing a given voxel volume, as well as compute and investigate the spatial and spectral properties of radio (to be compared with VLA or EOVSA data), (sub-)millimeter (ALMA), EUV (AIA/SDO), and X-ray (RHESSI) emission calculated from the model. The application integrates shared-object libraries containing fast free-free, gyrosynchrotron, and gyroresonance emission codes developed in FORTRAN and C++, and soft and hard X-ray and EUV codes developed in IDL. We use this tool to model and analyze an active region and compare the synthetic emission maps obtained in different wavelengths with observations.This work was partially supported by NSF grants AGS-1250374, AGS-1262772, NASA grant NNX14AC87G, the Marie Curie International Research Staff Exchange Scheme "Radiosun" (PEOPLE-2011-IRSES-295272), RFBR grants 14-02-91157, 15-02-01089, 15-02-03717, 15

  8. Multi-Purpose, Multi-Reservoir Simulation on a PC

    DTIC Science & Technology

    1988-08-01

    The methodology and difficulties in converting a large, general purpose, mainframe, batch oriented computer program (for reservoir simulation ) to...work effectively in the PC environment are described in this paper. A brief overview of the present capabilities of the general purpose reservoir ... simulation program (HEC-5), that works on mainframe and MS DOS compatible computers, is also presented. Keywords: Simulation, Personal computer, Reservior

  9. A simulation technique for 3D MR-guided acoustic radiation force imaging

    PubMed Central

    Payne, Allison; de Bever, Josh; Farrer, Alexis; Coats, Brittany; Parker, Dennis L.; Christensen, Douglas A.

    2015-01-01

    Purpose: In magnetic resonance-guided focused ultrasound (MRgFUS) therapies, the in situ characterization of the focal spot location and quality is critical. MR acoustic radiation force imaging (MR-ARFI) is a technique that measures the tissue displacement caused by the radiation force exerted by the ultrasound beam. This work presents a new technique to model the displacements caused by the radiation force of an ultrasound beam in a homogeneous tissue model. Methods: When a steady-state point-source force acts internally in an infinite homogeneous medium, the displacement of the material in all directions is given by the Somigliana elastostatic tensor. The radiation force field, which is caused by absorption and reflection of the incident ultrasound intensity pattern, will be spatially distributed, and the tensor formulation takes the form of a convolution of a 3D Green’s function with the force field. The dynamic accumulation of MR phase during the ultrasound pulse can be theoretically accounted for through a time-of-arrival weighting of the Green’s function. This theoretical model was evaluated experimentally in gelatin phantoms of varied stiffness (125-, 175-, and 250-bloom). The acoustic and mechanical properties of the phantoms used as parameters of the model were measured using independent techniques. Displacements at focal depths of 30- and 45-mm in the phantoms were measured by a 3D spin echo MR-ARFI segmented-EPI sequence. Results: The simulated displacements agreed with the MR-ARFI measured displacements for all bloom values and focal depths with a normalized RMS difference of 0.055 (range 0.028–0.12). The displacement magnitude decreased and the displacement pattern broadened with increased bloom value for both focal depths, as predicted by the theory. Conclusions: A new technique that models the displacements caused by the radiation force of an ultrasound beam in a homogeneous tissue model theory has been rigorously validated through comparison

  10. A simulation technique for 3D MR-guided acoustic radiation force imaging

    SciTech Connect

    Payne, Allison; Bever, Josh de; Farrer, Alexis; Coats, Brittany; Parker, Dennis L.; Christensen, Douglas A.

    2015-02-15

    Purpose: In magnetic resonance-guided focused ultrasound (MRgFUS) therapies, the in situ characterization of the focal spot location and quality is critical. MR acoustic radiation force imaging (MR-ARFI) is a technique that measures the tissue displacement caused by the radiation force exerted by the ultrasound beam. This work presents a new technique to model the displacements caused by the radiation force of an ultrasound beam in a homogeneous tissue model. Methods: When a steady-state point-source force acts internally in an infinite homogeneous medium, the displacement of the material in all directions is given by the Somigliana elastostatic tensor. The radiation force field, which is caused by absorption and reflection of the incident ultrasound intensity pattern, will be spatially distributed, and the tensor formulation takes the form of a convolution of a 3D Green’s function with the force field. The dynamic accumulation of MR phase during the ultrasound pulse can be theoretically accounted for through a time-of-arrival weighting of the Green’s function. This theoretical model was evaluated experimentally in gelatin phantoms of varied stiffness (125-, 175-, and 250-bloom). The acoustic and mechanical properties of the phantoms used as parameters of the model were measured using independent techniques. Displacements at focal depths of 30- and 45-mm in the phantoms were measured by a 3D spin echo MR-ARFI segmented-EPI sequence. Results: The simulated displacements agreed with the MR-ARFI measured displacements for all bloom values and focal depths with a normalized RMS difference of 0.055 (range 0.028–0.12). The displacement magnitude decreased and the displacement pattern broadened with increased bloom value for both focal depths, as predicted by the theory. Conclusions: A new technique that models the displacements caused by the radiation force of an ultrasound beam in a homogeneous tissue model theory has been rigorously validated through comparison

  11. Parallel computing simulation of electrical excitation and conduction in the 3D human heart.

    PubMed

    Di Yu; Dongping Du; Hui Yang; Yicheng Tu

    2014-01-01

    A correctly beating heart is important to ensure adequate circulation of blood throughout the body. Normal heart rhythm is produced by the orchestrated conduction of electrical signals throughout the heart. Cardiac electrical activity is the resulted function of a series of complex biochemical-mechanical reactions, which involves transportation and bio-distribution of ionic flows through a variety of biological ion channels. Cardiac arrhythmias are caused by the direct alteration of ion channel activity that results in changes in the AP waveform. In this work, we developed a whole-heart simulation model with the use of massive parallel computing with GPGPU and OpenGL. The simulation algorithm was implemented under several different versions for the purpose of comparisons, including one conventional CPU version and two GPU versions based on Nvidia CUDA platform. OpenGL was utilized for the visualization / interaction platform because it is open source, light weight and universally supported by various operating systems. The experimental results show that the GPU-based simulation outperforms the conventional CPU-based approach and significantly improves the speed of simulation. By adopting modern computer architecture, this present investigation enables real-time simulation and visualization of electrical excitation and conduction in the large and complicated 3D geometry of a real-world human heart.

  12. 3D Multistage Simulation of Each Component of the GE90 Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Turner, Mark; Topp, Dave; Veres, Joe

    1999-01-01

    A 3D multistage simulation of each component of the GE90 Turbofan engine has been made. This includes 49 blade rows. A coupled simulation of all blade rows will be made very soon. The simulation is running using two levels of parallelism. The first level is on a blade row basis with information shared using files. The second level is using a grid domain decomposition with information shared using MPI. Timings will be shown for running on the SP2, an SGI Origin and a distributed system of HP workstations. On the HP workstations, the CHIMP version of MPI is used, with queuing supplied by LSF (Load Sharing Facility). A script-based control system is used to ensure reliability. An MPEG movie illustrating the flow simulation of the engine has been created using PV3, a parallel visualization library created by Bob Haimes of MIT. PVM is used to create a virtual machine from 10 HP workstations and display on an SGI workstation. A representative component simulation will be compared to rig data to demonstrate its usefulness in turbomachinery design and analysis.

  13. The Shock Dynamics of Heterogeneous YSO Jets: 3D Simulations Meet Multi-epoch Observations

    NASA Astrophysics Data System (ADS)

    Hansen, E. C.; Frank, A.; Hartigan, P.; Lebedev, S. V.

    2017-03-01

    High-resolution observations of young stellar object (YSO) jets show them to be composed of many small-scale knots or clumps. In this paper, we report results of 3D numerical simulations designed to study how such clumps interact and create morphologies and kinematic patterns seen in emission line observations. Our simulations focus on clump scale dynamics by imposing velocity differences between spherical, over-dense regions, which then lead to the formation of bow shocks as faster clumps overtake slower material. We show that much of the spatial structure apparent in emission line images of jets arises from the dynamics and interactions of these bow shocks. Our simulations show a variety of time-dependent features, including bright knots associated with Mach stems where the shocks intersect, a “frothy” emission structure that arises from the presence of the Nonlinear Thin Shell Instability along the surfaces of the bow shocks, and the merging and fragmentation of clumps. Our simulations use a new non-equilibrium cooling method to produce synthetic emission maps in Hα and [S ii]. These are directly compared to multi-epoch Hubble Space Telescope observations of Herbig–Haro jets. We find excellent agreement between features seen in the simulations and the observations in terms of both proper motion and morphologies. Thus we conclude that YSO jets may be dominated by heterogeneous structures and that interactions between these structures and the shocks they produce can account for many details of YSO jet evolution.

  14. Transient 3D numerical simulations of column collapse and pyroclastic density current scenarios at Vesuvius

    NASA Astrophysics Data System (ADS)

    Esposti Ongaro, T.; Neri, A.; Menconi, G.; de'Michieli Vitturi, M.; Marianelli, P.; Cavazzoni, C.; Erbacci, G.; Baxter, P. J.

    2008-12-01

    Numerical simulations of column collapse and pyroclastic density current (PDC) scenarios at Vesuvius were carried out using a transient 3D flow model based on multiphase transport laws. The model describes the dynamics of the collapse as well as the effects of the 3D topography of the volcano on PDC propagation. Source conditions refer to a medium-scale sub-Plinian event and consider a pressure-balanced jet. Simulation results provide new insights into the complex dynamics of these phenomena. In particular: 1) column collapse can be characterized by different regimes, from incipient collapse to partial or nearly total collapse, thus confirming the possibility of a transitional field of behaviour of the column characterized by the contemporaneous and/or intermittent occurrence of ash fallout and PDCs; 2) the collapse regime can be characterized by its fraction of eruptive mass reaching the ground and generating PDCs; 3) within the range of the investigated source conditions, the propagation and hazard potential of PDCs appear to be directly correlated with the flow-rate of the mass collapsing to the ground, rather than to the collapse height of the column (this finding is in contrast with predictions based on the energy-line concept, which simply correlates the PDC runout and kinetic energy with the collapse height of the column); 4) first-order values of hazard variables associated with PDCs (i.e., dynamic pressure, temperature, airborne ash concentration) can be derived from simulation results, thereby providing initial estimates for the quantification of damage scenarios; 5) for scenarios assuming a location of the central vent coinciding with that of the present Gran Cono, Mount Somma significantly influences the propagation of PDCs, largely reducing their propagation in the northern sector, and diverting mass toward the west and southeast, accentuating runouts and hazard variables for these sectors; 6) the 2D modelling approximation can force an artificial

  15. The simulation of 3D mass models in 2D digital mammography and breast tomosynthesis

    SciTech Connect

    Shaheen, Eman De Keyzer, Frederik; Bosmans, Hilde; Ongeval, Chantal Van; Dance, David R.; Young, Kenneth C.

    2014-08-15

    Purpose: This work proposes a new method of building 3D breast mass models with different morphological shapes and describes the validation of the realism of their appearance after simulation into 2D digital mammograms and breast tomosynthesis images. Methods: Twenty-five contrast enhanced MRI breast lesions were collected and each mass was manually segmented in the three orthogonal views: sagittal, coronal, and transversal. The segmented models were combined, resampled to have isotropic voxel sizes, triangularly meshed, and scaled to different sizes. These masses were referred to as nonspiculated masses and were then used as nuclei onto which spicules were grown with an iterative branching algorithm forming a total of 30 spiculated masses. These 55 mass models were projected into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. The realism of the appearance of these mass models was assessed by five radiologists via receiver operating characteristic (ROC) analysis when compared to 54 real masses. All lesions were also given a breast imaging reporting and data system (BIRADS) score. The data sets of 2D mammography and tomosynthesis were read separately. The Kendall's coefficient of concordance was used for the interrater observer agreement assessment for the BIRADS scores per modality. Further paired analysis, using the Wilcoxon signed rank test, of the BIRADS assessment between 2D and tomosynthesis was separately performed for the real masses and for the simulated masses. Results: The area under the ROC curves, averaged over all observers, was 0.54 (95% confidence interval [0.50, 0.66]) for the 2D study, and 0.67 (95% confidence interval [0.55, 0.79]) for the tomosynthesis study. According to the BIRADS scores, the nonspiculated and the spiculated masses varied in their degrees of malignancy from normal (BIRADS 1) to highly

  16. Augmented reality intravenous injection simulator based 3D medical imaging for veterinary medicine.

    PubMed

    Lee, S; Lee, J; Lee, A; Park, N; Lee, S; Song, S; Seo, A; Lee, H; Kim, J-I; Eom, K

    2013-05-01

    Augmented reality (AR) is a technology which enables users to see the real world, with virtual objects superimposed upon or composited with it. AR simulators have been developed and used in human medicine, but not in veterinary medicine. The aim of this study was to develop an AR intravenous (IV) injection simulator to train veterinary and pre-veterinary students to perform canine venipuncture. Computed tomographic (CT) images of a beagle dog were scanned using a 64-channel multidetector. The CT images were transformed into volumetric data sets using an image segmentation method and were converted into a stereolithography format for creating 3D models. An AR-based interface was developed for an AR simulator for IV injection. Veterinary and pre-veterinary student volunteers were randomly assigned to an AR-trained group or a control group trained using more traditional methods (n = 20/group; n = 8 pre-veterinary students and n = 12 veterinary students in each group) and their proficiency at IV injection technique in live dogs was assessed after training was completed. Students were also asked to complete a questionnaire which was administered after using the simulator. The group that was trained using an AR simulator were more proficient at IV injection technique using real dogs than the control group (P ≤ 0.01). The students agreed that they learned the IV injection technique through the AR simulator. Although the system used in this study needs to be modified before it can be adopted for veterinary educational use, AR simulation has been shown to be a very effective tool for training medical personnel. Using the technology reported here, veterinary AR simulators could be developed for future use in veterinary education.

  17. A faster method for 3D/2D medical image registration—a simulation study

    NASA Astrophysics Data System (ADS)

    Birkfellner, Wolfgang; Wirth, Joachim; Burgstaller, Wolfgang; Baumann, Bernard; Staedele, Harald; Hammer, Beat; Claudius Gellrich, Niels; Jacob, Augustinus Ludwig; Regazzoni, Pietro; Messmer, Peter

    2003-08-01

    3D/2D patient-to-computed-tomography (CT) registration is a method to determine a transformation that maps two coordinate systems by comparing a projection image rendered from CT to a real projection image. Iterative variation of the CT's position between rendering steps finally leads to exact registration. Applications include exact patient positioning in radiation therapy, calibration of surgical robots, and pose estimation in computer-aided surgery. One of the problems associated with 3D/2D registration is the fact that finding a registration includes solving a minimization problem in six degrees of freedom (dof) in motion. This results in considerable time requirements since for each iteration step at least one volume rendering has to be computed. We show that by choosing an appropriate world coordinate system and by applying a 2D/2D registration method in each iteration step, the number of iterations can be grossly reduced from n6 to n5. Here, n is the number of discrete variations around a given coordinate. Depending on the configuration of the optimization algorithm, this reduces the total number of iterations necessary to at least 1/3 of it's original value. The method was implemented and extensively tested on simulated x-ray images of a tibia, a pelvis and a skull base. When using one projective image and a discrete full parameter space search for solving the optimization problem, average accuracy was found to be 1.0 +/- 0.6(°) and 4.1 +/- 1.9 (mm) for a registration in six parameters, and 1.0 +/- 0.7(°) and 4.2 +/- 1.6 (mm) when using the 5 + 1 dof method described in this paper. Time requirements were reduced by a factor 3.1. We conclude that this hardware-independent optimization of 3D/2D registration is a step towards increasing the acceptance of this promising method for a wide number of clinical applications.

  18. A faster method for 3D/2D medical image registration--a simulation study.

    PubMed

    Birkfellner, Wolfgang; Wirth, Joachim; Burgstaller, Wolfgang; Baumann, Bernard; Staedele, Harald; Hammer, Beat; Gellrich, Niels Claudius; Jacob, Augustinus Ludwig; Regazzoni, Pietro; Messmer, Peter

    2003-08-21

    3D/2D patient-to-computed-tomography (CT) registration is a method to determine a transformation that maps two coordinate systems by comparing a projection image rendered from CT to a real projection image. Iterative variation of the CT's position between rendering steps finally leads to exact registration. Applications include exact patient positioning in radiation therapy, calibration of surgical robots, and pose estimation in computer-aided surgery. One of the problems associated with 3D/2D registration is the fact that finding a registration includes solving a minimization problem in six degrees of freedom (dof) in motion. This results in considerable time requirements since for each iteration step at least one volume rendering has to be computed. We show that by choosing an appropriate world coordinate system and by applying a 2D/2D registration method in each iteration step, the number of iterations can be grossly reduced from n6 to n5. Here, n is the number of discrete variations around a given coordinate. Depending on the configuration of the optimization algorithm, this reduces the total number of iterations necessary to at least 1/3 of it's original value. The method was implemented and extensively tested on simulated x-ray images of a tibia, a pelvis and a skull base. When using one projective image and a discrete full parameter space search for solving the optimization problem, average accuracy was found to be 1.0 +/- 0.6(degrees) and 4.1 +/- 1.9 (mm) for a registration in six parameters, and 1.0 +/- 0.7(degrees) and 4.2 +/- 1.6 (mm) when using the 5 + 1 dof method described in this paper. Time requirements were reduced by a factor 3.1. We conclude that this hardware-independent optimization of 3D/2D registration is a step towards increasing the acceptance of this promising method for a wide number of clinical applications.

  19. Velocity and Density Models Incorporating the Cascadia Subduction Zone for 3D Earthquake Ground Motion Simulations

    USGS Publications Warehouse

    Stephenson, William J.

    2007-01-01

    INTRODUCTION In support of earthquake hazards and ground motion studies in the Pacific Northwest, three-dimensional P- and S-wave velocity (3D Vp and Vs) and density (3D rho) models incorporating the Cascadia subduction zone have been developed for the region encompassed from about 40.2?N to 50?N latitude, and from about -122?W to -129?W longitude. The model volume includes elevations from 0 km to 60 km (elevation is opposite of depth in model coordinates). Stephenson and Frankel (2003) presented preliminary ground motion simulations valid up to 0.1 Hz using an earlier version of these models. The version of the model volume described here includes more structural and geophysical detail, particularly in the Puget Lowland as required for scenario earthquake simulations in the development of the Seattle Urban Hazards Maps (Frankel and others, 2007). Olsen and others (in press) used the model volume discussed here to perform a Cascadia simulation up to 0.5 Hz using a Sumatra-Andaman Islands rupture history. As research from the EarthScope Program (http://www.earthscope.org) is published, a wealth of important detail can be added to these model volumes, particularly to depths of the upper-mantle. However, at the time of development for this model version, no EarthScope-specific results were incorporated. This report is intended to be a reference for colleagues and associates who have used or are planning to use this preliminary model in their research. To this end, it is intended that these models will be considered a beginning template for a community velocity model of the Cascadia region as more data and results become available.

  20. Large-eddy simulation of 3D turbulent flow past a complete marine hydrokinetic turbine

    NASA Astrophysics Data System (ADS)

    Kang, S.; Sotiropoulos, F.

    2011-12-01

    A high-resolution computational framework was recently developed by Kang et al (Adv. Water Resour., submitted) for simulating three-dimensional (3D), turbulent flow past real-life, complete marine hydrokinetic (MHK) turbine configurations. In this model the complex turbine geometry is resolved by employing the curvilinear immersed boundary (CURVIB) method, which solves the 3D unsteady incompressible Navier-Stokes equations in generalized curvilinear domains with embedded arbitrarily complex, moving and/or stationary immersed boundaries (Ge and Sotiropoulos, 2007). Turbulence is simulated using the large-eddy simulation (LES) approach adapted in the context of the CURVIB method, with a wall model based on solving the simplified boundary layer equations used to reconstruct boundary conditions near all solid surfaces (Kang et al., 2011). The model can resolve the flow patterns generated by the rotor and all stationary components of the turbine as well as the interactions of the flow structures with the channel bed. We apply this model to carry out LES of the flow past the model-size hydrokinetic turbine deployed in the St. Anthony Falls Laboratory main channel. The mean velocities and second-order turbulence statistics measured in the downstream wake using acoustic Doppler velocimetry (ADV) are compared with the LES results. The comparisons show that the computed mean velocities and turbulent stresses are in good agreement with the measurements. The high-resolution LES data are used to explore physically important downstream flow characteristics such as the time-averaged wake structure, recovery of cross-sectionally averaged power potential, near-bed scour potential, etc. This work is supported by Verdant Power.

  1. The dark side of photovoltaic — 3D simulation of glare assessing risk and discomfort

    SciTech Connect

    Rose, Thomas; Wollert, Alexander

    2015-04-15

    Photovoltaic (PV) systems form an important force in the implementation of renewable energies, but as we all know, the force has always its dark side. Besides efficiency considerations and discussions about architectures of power distribution networks, the increasing numbers of installations of PV systems for implementing renewable energies have secondary effects. PV systems can generate glare due to optical reflections and hence might be a serious concern. On the one hand, glare could affect safety, e.g. regarding traffic. On the other hand, glare is a constant source of discomfort in vicinities of PV systems. Hence, assessment of glare is decisive for the success of renewable energies near municipalities and traffic zones for the success of solar power. Several courts decided on the change of PV systems and even on their de-installation because of glare effects. Thus, location-based assessments are required to limit potential reflections and to avoid risks for public infrastructure or discomfort of residents. The question arises on how to calculate reflections accurately according to the environment's topography. Our approach is founded in a 3D-based simulation methodology to calculate and visualize reflections based on the geometry of the environment of PV systems. This computational model is implemented by an interactive tool for simulation and visualization. Hence, project planners receive flexible assistance for adjusting the parameters of solar panels amid the planning process and in particular before the installation of a PV system. - Highlights: • Solar panels cause glare that impacts neighborhoods and traffic infrastructures. • Glare might cause disability and discomfort. • 3D environment for the calculation of glare • Interactive tool to simulate and visualize reflections • Impact assessment of solar power plant farms.

  2. A Completely 3D Model for the Simulation of Mechanized Tunnel Excavation

    NASA Astrophysics Data System (ADS)

    Zhao, Kai; Janutolo, Michele; Barla, Giovanni

    2012-07-01

    For long deep tunnels as currently under construction through the Alps, mechanized excavation using tunnel boring machines (TBMs) contributes significantly to savings in construction time and costs. Questions are, however, posed due to the severe ground conditions which are in cases anticipated or encountered along the main tunnel alignment. A major geological hazard is the squeezing of weak rocks, but also brittle failure can represent a significant problem. For the design of mechanized tunnelling in such conditions, the complex interaction between the rock mass, the tunnel machine, its system components, and the tunnel support need to be analysed in detail and this can be carried out by three-dimensional (3D) models including all these components. However, the state-of-the-art shows that very few fully 3D models for mechanical deep tunnel excavation in rock have been developed so far. A completely three-dimensional simulator of mechanised tunnel excavation is presented in this paper. The TBM of reference is a technologically advanced double shield TBM designed to cope with both conditions. Design analyses with reference to spalling hazard along the Brenner and squeezing along the Lyon-Turin Base Tunnel are discussed.

  3. New Insights on Pulsating White Dwarfs from 3D Radiation-Hydrodynamical Simulations

    NASA Astrophysics Data System (ADS)

    Tremblay, Pier-Emmanuel; Fontaine, Gilles; Ludwig, Hans-Günter

    2015-08-01

    We have recently computed a grid of 3D radiation-hydrodynamical simulations for the atmosphere of 70 pure-hydrogen DA white dwarfs in the range 7.0 < log g < 9.0. This includes the full ZZ Ceti instability strip where DA white dwarfs are pulsating, by far the most common type of degenerate pulsators. We have significantly improved the theoretical framework to study these objects by removing the free parameters of 1D convection, which were previously a major modeling hurdle. We will compare our new models with the observed sample of ZZ Ceti stars and highlight the improved derived properties of these objects. In particular, the new spectroscopically determined 3D atmospheric parameters allow for an improved definition of instability strip edges. We have also made new predictions for the size of convection zones, which significantly impact the position where the pulsations are driven, and the region of the HR diagram where white dwarfs are expected to pulsate. Finally, we will present new results from non-adiabatic pulsation calculations.

  4. Simulation of 3-D Nonequilibrium Seeded Air Flow in the NASA-Ames MHD Channel

    NASA Technical Reports Server (NTRS)

    Gupta, Sumeet; Tannehill, John C.; Mehta, Unmeel B.

    2004-01-01

    The 3-D nonequilibrium seeded air flow in the NASA-Ames experimental MHD channel has been numerically simulated. The channel contains a nozzle section, a center section, and an accelerator section where magnetic and electric fields can be imposed on the flow. In recent tests, velocity increases of up to 40% have been achieved in the accelerator section. The flow in the channel is numerically computed us ing a 3-D parabolized Navier-Stokes (PNS) algorithm that has been developed to efficiently compute MHD flows in the low magnetic Reynolds number regime: The MHD effects are modeled by introducing source terms into the PNS equations which can then be solved in a very efficient manner. The algorithm has been extended in the present study to account for nonequilibrium seeded air flows. The electrical conductivity of the flow is determined using the program of Park. The new algorithm has been used to compute two test cases that match the experimental conditions. In both cases, magnetic and electric fields are applied to the seeded flow. The computed results are in good agreement with the experimental data.

  5. 3D design and electric simulation of a silicon drift detector using a spiral biasing adapter

    NASA Astrophysics Data System (ADS)

    Li, Yu-yun; Xiong, Bo; Li, Zheng

    2016-09-01

    The detector system of combining a spiral biasing adapter (SBA) with a silicon drift detector (SBA-SDD) is largely different from the traditional silicon drift detector (SDD), including the spiral SDD. It has a spiral biasing adapter of the same design as a traditional spiral SDD and an SDD with concentric rings having the same radius. Compared with the traditional spiral SDD, the SBA-SDD separates the spiral's functions of biasing adapter and the p-n junction definition. In this paper, the SBA-SDD is simulated using a Sentaurus TCAD tool, which is a full 3D device simulation tool. The simulated electric characteristics include electric potential, electric field, electron concentration, and single event effect. Because of the special design of the SBA-SDD, the SBA can generate an optimum drift electric field in the SDD, comparable with the conventional spiral SDD, while the SDD can be designed with concentric rings to reduce surface area. Also the current and heat generated in the SBA are separated from the SDD. To study the single event response, we simulated the induced current caused by incident heavy ions (20 and 50 μm penetration length) with different linear energy transfer (LET). The SBA-SDD can be used just like a conventional SDD, such as X-ray detector for energy spectroscopy and imaging, etc.

  6. Application Of Moldex3D For Thin-wall Injection Moulding Simulation

    NASA Astrophysics Data System (ADS)

    Šercer, Mladen; Godec, Damir; Bujanić, Božo

    2007-05-01

    The benefits associated with decreasing wall thicknesses below their current values are still measurable and desired even if the final wall thickness is nowhere near those of the aggressive portable electronics industry. It is important to note that gains in wall section reduction do not always occur without investment, in this case, in tooling and machinery upgrades. Equally important is the fact that productivity and performance benefits of reduced material usage, fast cycle times, and lighter weight can often outweigh most of the added costs. In order to eliminate unnecessary mould trials, minimize product development cycle, reduce overall costs and improve product quality, polymeric engineers use new CAE technology (Computer Aided Engineering). This technology is a simulation tool, which combines proven theories, material properties and process conditions to generate realistic simulations and produce valuable recommendations. Based on these recommendations, an optional combination of product design, material and process conditions can be identified. In this work, Moldex3D software was used for simulation of injection moulding in order to avoid potential moulding problems. The results gained from the simulation were used for the optimization of an existing product design, for mould development and for optimization of processing parameters, e.g. injection pressure, mould cavity temperature, etc.

  7. Aeroacoustic Simulations of a Nose Landing Gear Using FUN3D on Pointwise Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Vatsa, Veer N.; Khorrami, Mehdi R.; Rhoads, John; Lockard, David P.

    2015-01-01

    Numerical simulations have been performed for a partially-dressed, cavity-closed (PDCC) nose landing gear configuration that was tested in the University of Florida's open-jet acoustic facility known as the UFAFF. The unstructured-grid flow solver FUN3D is used to compute the unsteady flow field for this configuration. Mixed-element grids generated using the Pointwise(TradeMark) grid generation software are used for these simulations. Particular care is taken to ensure quality cells and proper resolution in critical areas of interest in an effort to minimize errors introduced by numerical artifacts. A hybrid Reynolds-averaged Navier-Stokes/large eddy simulation (RANS/LES) turbulence model is used for these simulations. Solutions are also presented for a wall function model coupled to the standard turbulence model. Time-averaged and instantaneous solutions obtained on these Pointwise grids are compared with the measured data and previous numerical solutions. The resulting CFD solutions are used as input to a Ffowcs Williams-Hawkings noise propagation code to compute the farfield noise levels in the flyover and sideline directions. The computed noise levels compare well with previous CFD solutions and experimental data.

  8. Finite element simulation of HIP-process to produce 3d near net shape parts

    SciTech Connect

    Zadeh, M.K.

    1996-12-31

    One of the major problems when producing powder metallurgy parts through hot isostatic pressing (HIP) is the non homogeneous shrinkage of HIP-capsule during the process. This leads to time and cost consuming machining of the HIP parts. In order to reduce the machining to a minimum, one can try to simulate the HIP-process by means of numerical methods. Hereby, the part distortion can be predicted, and hence a new HIP-capsule can be designed in such a way to prevent the distortion partly or even completely. In the following, a finite element method is used, on one hand, to simulate part shrinkage during HIP process; on the other hand a method is integrated in this simulation to optimize the HIP-capsule geometry. For the determination of material dependent parameters, a mixture of theoretical and experimental methods is used. Results of simulation are verified for a complex 3d HIP part out of TiAl6V4.

  9. Validation of 3-D Ice Accretion Measurement Methodology for Experimental Aerodynamic Simulation

    NASA Technical Reports Server (NTRS)

    Broeren, Andy P.; Addy, Harold E., Jr.; Lee, Sam; Monastero, Marianne C.

    2015-01-01

    Determining the adverse aerodynamic effects due to ice accretion often relies on dry-air wind-tunnel testing of artificial, or simulated, ice shapes. Recent developments in ice-accretion documentation methods have yielded a laser-scanning capability that can measure highly three-dimensional (3-D) features of ice accreted in icing wind tunnels. The objective of this paper was to evaluate the aerodynamic accuracy of ice-accretion simulations generated from laser-scan data. Ice-accretion tests were conducted in the NASA Icing Research Tunnel using an 18-in. chord, two-dimensional (2-D) straight wing with NACA 23012 airfoil section. For six ice-accretion cases, a 3-D laser scan was performed to document the ice geometry prior to the molding process. Aerodynamic performance testing was conducted at the University of Illinois low-speed wind tunnel at a Reynolds number of 1.8 × 10(exp 6) and a Mach number of 0.18 with an 18-in. chord NACA 23012 airfoil model that was designed to accommodate the artificial ice shapes. The ice-accretion molds were used to fabricate one set of artificial ice shapes from polyurethane castings. The laser-scan data were used to fabricate another set of artificial ice shapes using rapid prototype manufacturing such as stereolithography. The iced-airfoil results with both sets of artificial ice shapes were compared to evaluate the aerodynamic simulation accuracy of the laser-scan data. For five of the six ice-accretion cases, there was excellent agreement in the iced-airfoil aerodynamic performance between the casting and laser-scan based simulations. For example, typical differences in iced-airfoil maximum lift coefficient were less than 3 percent with corresponding differences in stall angle of approximately 1 deg or less. The aerodynamic simulation accuracy reported in this paper has demonstrated the combined accuracy of the laser-scan and rapid-prototype manufacturing approach to simulating ice accretion for a NACA 23012 airfoil. For several

  10. 3D Simulation of Missing Pellet Surface Defects in Light Water Reactor Fuel Rods

    SciTech Connect

    B.W. Spencer; J.D. Hales; S.R. Novascone; R.L. Williamson

    2012-09-01

    The cladding on light water reactor (LWR) fuel rods provides a stable enclosure for fuel pellets and serves as a first barrier against fission product release. Consequently, it is important to design fuel to prevent cladding failure due to mechanical interactions with fuel pellets. Cladding stresses can be effectively limited by controlling power increase rates. However, it has been shown that local geometric irregularities caused by manufacturing defects known as missing pellet surfaces (MPS) in fuel pellets can lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. Nuclear fuel performance codes commonly use a 1.5D (axisymmetric, axially-stacked, one-dimensional radial) or 2D axisymmetric representation of the fuel rod. To study the effects of MPS defects, results from 1.5D or 2D fuel performance analyses are typically mapped to thermo-mechanical models that consist of a 2D plane-strain slice or a full 3D representation of the geometry of the pellet and clad in the region of the defect. The BISON fuel performance code developed at Idaho National Laboratory employs either a 2D axisymmetric or 3D representation of the full fuel rod. This allows for a computational model of the full fuel rod to include local defects. A 3D thermo-mechanical model is used to simulate the global fuel rod behavior, and includes effects on the thermal and mechanical behavior of the fuel due to accumulation of fission products, fission gas production and release, and the effects of fission gas accumulation on thermal conductivity across the fuel-clad gap. Local defects can be modeled simply by including them in the 3D fuel rod model, without the need for mapping between two separate models. This allows for the complete set of physics used in a fuel performance analysis to be included naturally in the computational representation of the local defect, and for the effects of the

  11. Application of advanced reservoir characterization, simulation and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Annual report

    SciTech Connect

    Dutton, S.P.; Asquith, G.B.; Barton, M.D.; Cole, A.G.; Gogas, J.; Malik, M.A.; Clift, S.J.; Guzman, J.I.

    1997-11-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. This project involves reservoir characterization of two Late Permian slope and basin clastic reservoirs in the Delaware Basin, West Texas, followed by a field demonstration in one of the fields. The fields being investigated are Geraldine Ford and Ford West fields in Reeves and Culberson Counties, Texas. Project objectives are divided into two major phases, reservoir characterization and implementation. The objectives of the reservoir characterization phase of the project were to provide a detailed understanding of the architecture and heterogeneity of the two fields, the Ford Geraldine unit and Ford West field. Reservoir characterization utilized 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once reservoir characterized was completed, a pilot area of approximately 1 mi{sup 2} at the northern end of the Ford Geraldine unit was chosen for reservoir simulation. This report summarizes the results of the second year of reservoir characterization.

  12. GPU-advanced 3D electromagnetic simulations of superconductors in the Ginzburg–Landau formalism

    SciTech Connect

    Stošić, Darko; Stošić, Dušan; Ludermir, Teresa

    2016-10-01

    Ginzburg–Landau theory is one of the most powerful phenomenological theories in physics, with particular predictive value in superconductivity. The formalism solves coupled nonlinear differential equations for both the electronic and magnetic responsiveness of a given superconductor to external electromagnetic excitations. With order parameter varying on the short scale of the coherence length, and the magnetic field being long-range, the numerical handling of 3D simulations becomes extremely challenging and time-consuming for realistic samples. Here we show precisely how one can employ graphics-processing units (GPUs) for this type of calculations, and obtain physics answers of interest in a reasonable time-frame – with speedup of over 100× compared to best available CPU implementations of the theory on a 256{sup 3} grid.

  13. 3D MHD SIMULATION OF FLARE SUPRA-ARCADE DOWNFLOWS IN A TURBULENT CURRENT SHEET MEDIUM

    SciTech Connect

    Cécere, M.; Zurbriggen, E.; Costa, A.; Schneiter, M.

    2015-07-01

    Supra-arcade downflows (SADs) are sunward, generally dark, plasma density depletions originated above posteruption flare arcades. In this paper, using 3D MHD simulations we investigate whether the SAD cavities can be produced by a direct combination of the tearing mode and Kelvin–Helmholtz instabilities leading to a turbulent current sheet (CS) medium or if the current sheet is merely the background where SADs are produced, triggered by an impulsive deposition of energy. We find that to give an account of the observational dark lane structures an addition of local energy, provided by a reconnection event, is required. We suggest that there may be a closed relation between characteristic SAD sizes and CS widths that must be satisfied to obtain an observable SAD.

  14. PAB3D Simulations of a Nozzle with Fluidic Injection for Yaw Thrust-Vector Control

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.

    1998-01-01

    An experimental and computational study was conducted on an exhaust nozzle with fluidic injection for yaw thrust-vector control. The nozzle concept was tested experimentally in the NASA Langley Jet Exit Test Facility (JETF) at nozzle pressure ratios up to 4 and secondary fluidic injection flow rates up to 15 percent of the primary flow rate. Although many injection-port geometries and two nozzle planforms (symmetric and asymmetric) were tested experimentally, this paper focuses on the computational results of the more successful asymmetric planform with a slot injection port. This nozzle concept was simulated with the Navier-Stokes flow solver, PAB3D, invoking the Shih, Zhu, and Lumley algebraic Reynolds stress turbulence model (ASM) at nozzle pressure ratios (NPRs) of 2,3, and 4 with secondary to primary injection flow rates (w(sub s)/w(sub p)) of 0, 2, 7 and 10 percent.

  15. Parallel 3D Finite Element Particle-in-Cell Simulations with Pic3P

    SciTech Connect

    Candel, A.; Kabel, A.; Lee, L.; Li, Z.; Ng, C.; Schussman, G.; Ko, K.; Ben-Zvi, I.; Kewisch, J.; /Brookhaven

    2009-06-19

    SLAC's Advanced Computations Department (ACD) has developed the parallel 3D Finite Element electromagnetic Particle-In-Cell code Pic3P. Designed for simulations of beam-cavity interactions dominated by space charge effects, Pic3P solves the complete set of Maxwell-Lorentz equations self-consistently and includes space-charge, retardation and boundary effects from first principles. Higher-order Finite Element methods with adaptive refinement on conformal unstructured meshes lead to highly efficient use of computational resources. Massively parallel processing with dynamic load balancing enables large-scale modeling of photoinjectors with unprecedented accuracy, aiding the design and operation of next-generation accelerator facilities. Applications include the LCLS RF gun and the BNL polarized SRF gun.

  16. Simulation of a 3D unsteady flow in an axial turbine stage

    NASA Astrophysics Data System (ADS)

    Straka, Petr

    2012-04-01

    The contribution deals with a numerical simulation of an unsteady flow in an axial turbine stage. The solution is performed using an in-house numerical code developed in the Aeronautical and Test Institute, Plc. in Prague. The numerical code is based on a finite volume discretization of governing equations (Favre averaged Navier-Stokes equations) and a two-equations turbulence model. The temporal integration is based on the implicit second-order backward Euler formula, which is realized through the iteration process in dual time. The proposed numerical method is used for solution of the 3D, unsteady, viscous turbulent flow of a perfect gas in the axial turbine stage. The flow path consists of an input nozzle, stator blade-wheel, rotor blade-wheel, a shroud-seal gap and a diffuser. Attention is paid to the influence of a secondary flow structures, such as generated vortices and flow in shroud-seal gap.

  17. GPU-advanced 3D electromagnetic simulations of superconductors in the Ginzburg-Landau formalism

    NASA Astrophysics Data System (ADS)

    Stošić, Darko; Stošić, Dušan; Ludermir, Teresa; Stošić, Borko; Milošević, Milorad V.

    2016-10-01

    Ginzburg-Landau theory is one of the most powerful phenomenological theories in physics, with particular predictive value in superconductivity. The formalism solves coupled nonlinear differential equations for both the electronic and magnetic responsiveness of a given superconductor to external electromagnetic excitations. With order parameter varying on the short scale of the coherence length, and the magnetic field being long-range, the numerical handling of 3D simulations becomes extremely challenging and time-consuming for realistic samples. Here we show precisely how one can employ graphics-processing units (GPUs) for this type of calculations, and obtain physics answers of interest in a reasonable time-frame - with speedup of over 100× compared to best available CPU implementations of the theory on a 2563 grid.

  18. Billion-atom synchronous parallel kinetic Monte Carlo simulations of critical 3D Ising systems

    SciTech Connect

    Martinez, E.; Monasterio, P.R.; Marian, J.

    2011-02-20

    An extension of the synchronous parallel kinetic Monte Carlo (spkMC) algorithm developed by Martinez et al. [J. Comp. Phys. 227 (2008) 3804] to discrete lattices is presented. The method solves the master equation synchronously by recourse to null events that keep all processors' time clocks current in a global sense. Boundary conflicts are resolved by adopting a chessboard decomposition into non-interacting sublattices. We find that the bias introduced by the spatial correlations attendant to the sublattice decomposition is within the standard deviation of serial calculations, which confirms the statistical validity of our algorithm. We have analyzed the parallel efficiency of spkMC and find that it scales consistently with problem size and sublattice partition. We apply the method to the calculation of scale-dependent critical exponents in billion-atom 3D Ising systems, with very good agreement with state-of-the-art multispin simulations.

  19. Venus resurfacing rates: Constraints provided by 3-D Monte Carlo simulations

    NASA Technical Reports Server (NTRS)

    Bullock, M. A.; Grinspoon, D. H.; Head, J. W.

    1993-01-01

    A 3-D Monte Carlo model that simulates the evolving surface of Venus under the influence of a flux of impacting objects and a variety of styles of volcanic resurfacing was implemented. For given rates of impact events and resurfacing, the model predicts the size-frequency and areal distributions of surviving impact craters as a function of time. The number of craters partially modified by volcanic events is also calculated as the surface evolves. It was found that a constant, global resurfacing rate of approximately 0.4 km(sup 3)/yr is required to explain the observed distributions of both the entire crater population, and the population of craters partially modified by volcanic processes.

  20. Evaluation of simulation-based scatter correction for 3-D PET cardiac imaging

    SciTech Connect

    Watson, C.C.; Newport, D.; Casey, M.E.; Kemp, R.A. de; Beanlands, R.S.; Schmand, M. |

    1997-02-01

    Quantitative imaging of the human thorax poses one of the most difficult challenges for three-dimensional (3-D) (septaless) positron emission tomography (PET), due to the strong attenuation of the annihilation radiation and the large contribution of scattered photons to the data. In [{sup 18}F] fluorodeoxyglucose (FDG) studies of the heart with the patient`s arms in the field of view, the contribution of scattered events can exceed 50% of the total detected coincidences. Accurate correction for this scatter component is necessary for meaningful quantitative image analysis and tracer kinetic modeling. For this reason, the authors have implemented a single-scatter simulation technique for scatter correction in positron volume imaging. In this paper they describe this algorithm and present scatter correction results from human and chest phantom studies.

  1. Cognitive/emotional models for human behavior representation in 3D avatar simulations

    NASA Astrophysics Data System (ADS)

    Peterson, James K.

    2004-08-01

    Simplified models of human cognition and emotional response are presented which are based on models of auditory/ visual polymodal fusion. At the core of these models is a computational model of Area 37 of the temporal cortex which is based on new isocortex models presented recently by Grossberg. These models are trained using carefully chosen auditory (musical sequences), visual (paintings) and higher level abstract (meta level) data obtained from studies of how optimization strategies are chosen in response to outside managerial inputs. The software modules developed are then used as inputs to character generation codes in standard 3D virtual world simulations. The auditory and visual training data also enable the development of simple music and painting composition generators which significantly enhance one's ability to validate the cognitive model. The cognitive models are handled as interacting software agents implemented as CORBA objects to allow the use of multiple language coding choices (C++, Java, Python etc) and efficient use of legacy code.

  2. 3D visualization of ultra-fine ICON climate simulation data

    NASA Astrophysics Data System (ADS)

    Röber, Niklas; Spickermann, Dela; Böttinger, Michael

    2016-04-01

    Advances in high performance computing and model development allow the simulation of finer and more detailed climate experiments. The new ICON model is based on an unstructured triangular grid and can be used for a wide range of applications, ranging from global coupled climate simulations down to very detailed and high resolution regional experiments. It consists of an atmospheric and an oceanic component and scales very well for high numbers of cores. This allows us to conduct very detailed climate experiments with ultra-fine resolutions. ICON is jointly developed in partnership with DKRZ by the Max Planck Institute for Meteorology and the German Weather Service. This presentation discusses our current workflow for analyzing and visualizing this high resolution data. The ICON model has been used for eddy resolving (<10km) ocean simulations, as well as for ultra-fine cloud resolving (120m) atmospheric simulations. This results in very large 3D time dependent multi-variate data that need to be displayed and analyzed. We have developed specific plugins for the free available visualization software ParaView and Vapor, which allows us to read and handle that much data. Within ParaView, we can additionally compare prognostic variables with performance data side by side to investigate the performance and scalability of the model. With the simulation running in parallel on several hundred nodes, an equal load balance is imperative. In our presentation we show visualizations of high-resolution ICON oceanographic and HDCP2 atmospheric simulations that were created using ParaView and Vapor. Furthermore we discuss our current efforts to improve our visualization capabilities, thereby exploring the potential of regular in-situ visualization, as well as of in-situ compression / post visualization.

  3. Simulation of light transport in scintillators based on 3D characterization of crystal surfaces.

    PubMed

    Roncali, Emilie; Cherry, Simon R

    2013-04-07

    In the development of positron emission tomography (PET) detectors, understanding and optimizing scintillator light collection is critical for achieving high performance, particularly when the design incorporates depth-of-interaction (DOI) encoding or time-of-flight information. Monte-Carlo simulations play an important role in guiding research in detector designs and popular software such as GATE now include models of light transport in scintillators. Although current simulation toolkits are able to provide accurate models of perfectly polished surfaces, they do not successfully predict light output for other surface finishes, for example those often used in DOI-encoding detectors. The lack of accuracy of those models mainly originates from a simplified description of rough surfaces as an ensemble of micro-facets determined by the distribution of their normal, typically a gaussian distribution. The user can specify the standard deviation of this distribution, but this parameter does not provide a full description of the surface reflectance properties. We propose a different approach based on 3D measurements of the surface using atomic force microscopy. Polished and rough (unpolished) crystals were scanned to compute the surface reflectance properties. The angular distributions of reflectance and reflected rays were computed and stored in look-up tables (LUTs). The LUTs account for the effect of incidence angle and were integrated in a light transport model. Crystals of different sizes were simulated with and without reflector. The simulated maximum light output and the light output as a function of DOI showed very good agreement with experimental characterization of the crystals, indicating that our approach provides an accurate model of polished and rough surfaces and could be used to predict light collection in scintillators. This model is based on a true 3D representation of the surface, makes no assumption about the surface and provides insight on the optical

  4. Simulation of light transport in scintillators based on 3D characterization of crystal surfaces

    NASA Astrophysics Data System (ADS)

    Roncali, Emilie; Cherry, Simon R.

    2013-04-01

    In the development of positron emission tomography (PET) detectors, understanding and optimizing scintillator light collection is critical for achieving high performance, particularly when the design incorporates depth-of-interaction (DOI) encoding or time-of-flight information. Monte-Carlo simulations play an important role in guiding research in detector designs and popular software such as GATE now include models of light transport in scintillators. Although current simulation toolkits are able to provide accurate models of perfectly polished surfaces, they do not successfully predict light output for other surface finishes, for example those often used in DOI-encoding detectors. The lack of accuracy of those models mainly originates from a simplified description of rough surfaces as an ensemble of micro-facets determined by the distribution of their normal, typically a Gaussian distribution. The user can specify the standard deviation of this distribution, but this parameter does not provide a full description of the surface reflectance properties. We propose a different approach based on 3D measurements of the surface using atomic force microscopy. Polished and rough (unpolished) crystals were scanned to compute the surface reflectance properties. The angular distributions of reflectance and reflected rays were computed and stored in look-up tables (LUTs). The LUTs account for the effect of incidence angle and were integrated in a light transport model. Crystals of different sizes were simulated with and without reflector. The simulated maximum light output and the light output as a function of DOI showed very good agreement with experimental characterization of the crystals, indicating that our approach provides an accurate model of polished and rough surfaces and could be used to predict light collection in scintillators. This model is based on a true 3D representation of the surface, makes no assumption about the surface and provides insight on the optical

  5. Curvilinear Immersed Boundary Method for Simulating Fluid Structure Interaction with Complex 3D Rigid Bodies

    PubMed Central

    Borazjani, Iman; Ge, Liang; Sotiropoulos, Fotis

    2010-01-01

    The sharp-interface CURVIB approach of Ge and Sotiropoulos [L. Ge, F. Sotiropoulos, A Numerical Method for Solving the 3D Unsteady Incompressible Navier-Stokes Equations in Curvilinear Domains with Complex Immersed Boundaries, Journal of Computational Physics 225 (2007) 1782–1809] is extended to simulate fluid structure interaction (FSI) problems involving complex 3D rigid bodies undergoing large structural displacements. The FSI solver adopts the partitioned FSI solution approach and both loose and strong coupling strategies are implemented. The interfaces between immersed bodies and the fluid are discretized with a Lagrangian grid and tracked with an explicit front-tracking approach. An efficient ray-tracing algorithm is developed to quickly identify the relationship between the background grid and the moving bodies. Numerical experiments are carried out for two FSI problems: vortex induced vibration of elastically mounted cylinders and flow through a bileaflet mechanical heart valve at physiologic conditions. For both cases the computed results are in excellent agreement with benchmark simulations and experimental measurements. The numerical experiments suggest that both the properties of the structure (mass, geometry) and the local flow conditions can play an important role in determining the stability of the FSI algorithm. Under certain conditions unconditionally unstable iteration schemes result even when strong coupling FSI is employed. For such cases, however, combining the strong-coupling iteration with under-relaxation in conjunction with the Aitken’s acceleration technique is shown to effectively resolve the stability problems. A theoretical analysis is presented to explain the findings of the numerical experiments. It is shown that the ratio of the added mass to the mass of the structure as well as the sign of the local time rate of change of the force or moment imparted on the structure by the fluid determine the stability and convergence of the

  6. A graphical user interface for calculation of 3D dose distribution using Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Chow, J. C. L.; Leung, M. K. K.

    2008-02-01

    A software graphical user interface (GUI) for calculation of 3D dose distribution using Monte Carlo (MC) simulation is developed using MATLAB. This GUI (DOSCTP) provides a user-friendly platform for DICOM CT-based dose calculation using EGSnrcMP-based DOSXYZnrc code. It offers numerous features not found in DOSXYZnrc, such as the ability to use multiple beams from different phase-space files, and has built-in dose analysis and visualization tools. DOSCTP is written completely in MATLAB, with integrated access to DOSXYZnrc and CTCREATE. The program function may be divided into four subgroups, namely, beam placement, MC simulation with DOSXYZnrc, dose visualization, and export. Each is controlled by separate routines. The verification of DOSCTP was carried out by comparing plans with different beam arrangements (multi-beam/photon arc) on an inhomogeneous phantom as well as patient CT between the GUI and Pinnacle3. DOSCTP was developed and verified with the following features: (1) a built-in voxel editor to modify CT-based DOSXYZnrc phantoms for research purposes; (2) multi-beam placement is possible, which cannot be achieved using the current DOSXYZnrc code; (3) the treatment plan, including the dose distributions, contours and image set can be exported to a commercial treatment planning system such as Pinnacle3 or to CERR using RTOG format for plan evaluation and comparison; (4) a built-in RTOG-compatible dose reviewer for dose visualization and analysis such as finding the volume of hot/cold spots in the 3D dose distributions based on a user threshold. DOSCTP greatly simplifies the use of DOSXYZnrc and CTCREATE, and offers numerous features that not found in the original user-code. Moreover, since phase-space beams can be defined and generated by the user, it is a particularly useful tool to carry out plans using specifically designed irradiators/accelerators that cannot be found in the Linac library of commercial treatment planning systems.

  7. Simulation of bacteria transport processes in a river with Flow3D

    NASA Astrophysics Data System (ADS)

    Schwarzwälder, Kordula; Bui, Minh Duc; Rutschmann, Peter

    2014-05-01

    Water quality aspects are getting more and more important due to the European water Framework directive (WFD). One problem related to this topic is the inflow of untreated wastewater due to combined sewer overflows into a river. The wastewater mixture contains even bacteria like E. coli and Enterococci which are markers for water quality. In our work we investigated the transport of these bacteria in river Isar by using a large-scale flume in the outside area of our lab (Oskar von Miller Institute). Therefor we could collect basic data and knowledge about the processes which occur during bacteria sedimentation and remobilisation. In our flume we could use the real grain with the exact size distribution curve as in the river Isar which we want to simulate and we had the chance to nurture a biofilm which is realistic for the analysed situation. This biofilm plays an important role in the remobilisation processes, because the bacteria are hindered to be washed out back into the bulk phase as fast and in such an amount as this would happen without biofilm. The results of our experiments are now used for a module in the 3D software Flow3D to simulate the effects of a point source inlet of raw wastewater on the water quality. Therefor we have to implement the bacteria not as a problem of concentration with advection and diffusion but as single particles which can be inactivated during the process of settling and need to be hindered from remobilisation by the biofilm. This biofilm has special characteristic, it is slippery and has a special thickness which influences the chance of bacteria being removed. To achieve realistic results we have to include the biofilm with more than a probabilistic-tool to make sure that our module is transferable. The module should be as flexible as possible to be improved step by step with increasing quality of dataset.

  8. Monte carlo simulation of 3-D buffered Ca(2+) diffusion in neuroendocrine cells.

    PubMed Central

    Gil, A; Segura, J; Pertusa, J A; Soria, B

    2000-01-01

    Buffered Ca(2+) diffusion in the cytosol of neuroendocrine cells is a plausible explanation for the slowness and latency in the secretion of hormones. We have developed a Monte Carlo simulation to treat the problem of 3-D diffusion and kinetic reactions of ions and buffers. The 3-D diffusion is modeled as a random walk process that follows the path of each ion and buffer molecule, combined locally with a stochastic treatment of the first-order kinetic reactions involved. Such modeling is able to predict [Ca(2+)] and buffer concentration time courses regardless of how low the calcium influx is, and it is therefore a convenient method for dealing with physiological calcium currents and concentrations. We study the effects of the diffusional and kinetic parameters of the model on the concentration time courses as well as on the local equilibrium of buffers with calcium. An in-mobile and fast endogenous buffer as described by, Biophys. J. 72:674-690) was able to reach local equilibrium with calcium; however, the exogenous buffers considered are displaced drastically from equilibrium at the start of the calcium pulse, particularly below the pores. The versatility of the method also allows the effect of different arrangements of calcium channels on submembrane gradients to be studied, including random distribution of calcium channels and channel clusters. The simulation shows how the particular distribution of channels or clusters can be of relevance for secretion in the case where the distribution of release granules is correlated with the channels or clusters. PMID:10620270

  9. 3-D Numerical Simulation of Hydrostatic Tests of Porous Rocks Using Adapted Constitutive Model

    NASA Astrophysics Data System (ADS)

    Chemenda, A. I.; Daniel, M.

    2014-12-01

    The high complexity and poor knowledge of the constitutive properties of porous rocks are principal obstacles for the modeling of their deformation. Normally, the constitutive lows are to be derived from the experimental data (nominal strains and stresses). They are known, however, to be sensitive to the mechanical instabilities within the rock specimen and the boundary (notably friction) conditions at its ends. To elucidate the impact of these conditions on the measured mechanical response we use 3-D finite-difference simulations of experimental tests. Modeling of hydrostatic tests was chosen because it does not typically involve deformation instabilities. The ends of the cylindrical 'rock sample' are in contact with the 'steel' elastic platens through the frictional interfaces. The whole system is subjected to a normal stress Pc applied to the external model surface. A new constitutive model of porous rocks with the cap-type yield function is used. This function is quadratic in the mean stress σm and depends on the inelastic strain γp in a way to generate strain softening at small σm and strain-hardening at high σm. The corresponding material parameters are defined from the experimental data and have clear interpretation in terms of the geometry of the yield surface. The constitutive model with this yield function and the Drucker-Prager plastic potential has been implemented in 3-D dynamic explicit code Flac3D. The results of an extensive set of numerical simulations at different model parameters will be presented. They show, in particular, that the shape of the 'numerical' hydrostats is very similar to that obtained from the experimental tests and that it is practically insensitive to the interface friction. On the other hand, the stress and strain fields within the specimen dramatically depend on this parameter. The inelastic deformation at the specimen's ends starts well before reaching the grain crushing pressure P* and evolves heterogeneously with Pc

  10. Simulation of instrumental intensities in the Tokyo Metropolitan area using a 3D attenuation structure model.

    NASA Astrophysics Data System (ADS)

    Panayotopoulos, Y.; Hirata, N.; Sakai, S.; Nakagawa, S.; Kasahara, K.

    2015-12-01

    In recent years the development of dense seismic networks in Japan has enabled high quality observations of instrumental intensities. However, the distribution of intensities of historical earthquakes can only be retrieved by the damage reports on historical documents. Their epicenter and magnitude can be roughly estimated from the intensity distribution, assuming that seismic intensity decays with distance. This approximation is not always accurate, since the amplitude of short period ground motion decays with focal distance and is affected by the 3D attenuation structure along the path and in addition displays frequency dependence. In order to estimate the location and size of a large historical earthquake, we need to accurately simulate the seismic intensity distribution, accounting for non linear attenuation of seismic waves along the path. The instrumental seismic intensities inside the Kanto basin observed at the Tokyo Metropolitan Seismic Observation network (MeSO-net) and Hi-net stations display unusual distribution patterns, with peak intensities observed several km away from the epicenter rather than at the stations closer to it. In order to understand the source of this intensity distribution, we estimated the theoretical instrumental intensities using a 3D attenuation structure and compare it to the observed intensity distribution. We first estimated a 3D attenuation structure using the spectral decay of seismic waves, by fitting the observed seismic wave spectrum to a theoretical spectrum using an ω2 model. The obtained model suggests Qs values of 50˜100 inside the Kanto basin and low Qs values < 300 in the area where the Philippine Sea plate meets the upper part of the Pacific plate. We then use an ω2 model in order to estimate the source acceleration spectrum of several earthquakes occurring below the Kanto basin at depths ranging 30~80 km. Our simulation shows that earthquakes occurring on the Pacific plate pass through the low Qs area inside the

  11. Realistic 3D Terrain Roaming and Real-Time Flight Simulation

    NASA Astrophysics Data System (ADS)

    Que, Xiang; Liu, Gang; He, Zhenwen; Qi, Guang

    2014-12-01

    This paper presents an integrate method, which can provide access to current status and the dynamic visible scanning topography, to enhance the interactive during the terrain roaming and real-time flight simulation. A digital elevation model and digital ortho-photo map data integrated algorithm is proposed as the base algorithm for our approach to build a realistic 3D terrain scene. A new technique with help of render to texture and head of display for generating the navigation pane is used. In the flight simulating, in order to eliminate flying "jump", we employs the multidimensional linear interpolation method to adjust the camera parameters dynamically and steadily. Meanwhile, based on the principle of scanning laser imaging, we draw pseudo color figures by scanning topography in different directions according to the real-time flying status. Simulation results demonstrate that the proposed algorithm is prospective for applications and the method can improve the effect and enhance dynamic interaction during the real-time flight.

  12. 3-D simulation of gases transport under condition of inert gas injection into goaf

    NASA Astrophysics Data System (ADS)

    Liu, Mao-Xi; Shi, Guo-Qing; Guo, Zhixiong; Wang, Yan-Ming; Ma, Li-Yang

    2016-12-01

    To prevent coal spontaneous combustion in mines, it is paramount to understand O2 gas distribution under condition of inert gas injection into goaf. In this study, the goaf was modeled as a 3-D porous medium based on stress distribution. The variation of O2 distribution influenced by CO2 or N2 injection was simulated based on the multi-component gases transport and the Navier-Stokes equations using Fluent. The numerical results without inert gas injection were compared with field measurements to validate the simulation model. Simulations with inert gas injection show that CO2 gas mainly accumulates at the goaf floor level; however, a notable portion of N2 gas moves upward. The evolution of the spontaneous combustion risky zone with continuous inert gas injection can be classified into three phases: slow inerting phase, rapid accelerating inerting phase, and stable inerting phase. The asphyxia zone with CO2 injection is about 1.25-2.4 times larger than that with N2 injection. The efficacy of preventing and putting out mine fires is strongly related with the inert gas injecting position. Ideal injections are located in the oxidation zone or the transitional zone between oxidation zone and heat dissipation zone.

  13. Simulation of abrasive flow machining process for 2D and 3D mixture models

    NASA Astrophysics Data System (ADS)

    Dash, Rupalika; Maity, Kalipada

    2015-12-01

    Improvement of surface finish and material removal has been quite a challenge in a finishing operation such as abrasive flow machining (AFM). Factors that affect the surface finish and material removal are media viscosity, extrusion pressure, piston velocity, and particle size in abrasive flow machining process. Performing experiments for all the parameters and accurately obtaining an optimized parameter in a short time are difficult to accomplish because the operation requires a precise finish. Computational fluid dynamics (CFD) simulation was employed to accurately determine optimum parameters. In the current work, a 2D model was designed, and the flow analysis, force calculation, and material removal prediction were performed and compared with the available experimental data. Another 3D model for a swaging die finishing using AFM was simulated at different viscosities of the media to study the effects on the controlling parameters. A CFD simulation was performed by using commercially available ANSYS FLUENT. Two phases were considered for the flow analysis, and multiphase mixture model was taken into account. The fluid was considered to be a

  14. 3D Visualization of Monte-Carlo Simulation's of HZE Track Structure and Initial Chemical Species

    NASA Technical Reports Server (NTRS)

    Plante, Ianik; Cucinotta, Francis A.

    2009-01-01

    Heavy ions biophysics is important for space radiation risk assessment [1] and hadron-therapy [2]. The characteristic of heavy ions tracks include a very high energy deposition region close to the track (<20 nm) denoted as the track core, and an outer penumbra region consisting of individual secondary electrons (6-rays). A still open question is the radiobiological effects of 6- rays relative to the track core. Of importance is the induction of double-strand breaks (DSB) [3] and oxidative damage to the biomolecules and the tissue matrix, considered the most important lesions for acute and long term effects of radiation. In this work, we have simulated a 56Fe26+ ion track of 1 GeV/amu with our Monte-Carlo code RITRACKS [4]. The simulation results have been used to calculate the energy depiction and initial chemical species in a "voxelized" space, which is then visualized in 3D. Several voxels with dose >1000 Gy are found in the penumbra, some located 0.1 mm from the track core. In computational models, the DSB induction probability is calculated with radial dose [6], which may not take into account the higher RBE of electron track ends for DSB induction. Therefore, these simulations should help improve models of DSB induction and our understanding of heavy ions biophysics.

  15. Numerical simulation of unsteady flow characteristics for cavitation around a 3-D hydrofoil

    NASA Astrophysics Data System (ADS)

    Ahn, S. H.; Xiao, Y. X.; Wang, Z. W.

    2015-01-01

    At present it is possible to predict more accurately by various numerical methods established for cavitation simulation around a hydrofoil. However, for the solution of the complex unsteady cavity flow, it is still marginal. In this paper, numerical method is adopted to simulate cavitation around 3-D NACA0015 hydrofoil with homogeneous two-phase flow calculation using commercial code CFX-solver with two turbulence models, the standard RNG k-epsilon turbulence model and the modified RNG k-epsilon turbulence model respectively. First, pressure coefficient for non-cavitating flow, time averaged values of unsteady cavity flow around a hydrofoil are verified to simulate more closely to an actual cavity flow. And then frequency analysis is performed with Fast Fourier Transform. The results show that the calculation results with modified RNG k-epsilon turbulence model agree with experimental results in terms of mean cavity length and pressure drop, but the unsteady flow characteristics of oscillating cavitation still deviate slightly in terms of unsteady cavity flow.

  16. 3D optical simulation formalism OPTOS for textured silicon solar cells.

    PubMed

    Tucher, Nico; Eisenlohr, Johannes; Kiefel, Peter; Höhn, Oliver; Hauser, Hubert; Peters, Marius; Müller, Claas; Goldschmidt, Jan Christoph; Bläsi, Benedikt

    2015-11-30

    In this paper we introduce the three-dimensional formulation of the OPTOS formalism, a matrix-based method that allows for the efficient simulation of non-coherent light propagation and absorption in thick textured sheets. As application examples, we calculate the absorptance of solar cells featuring textures on front and rear side with different feature sizes operating in different optical regimes. A discretization of polar and azimuth angle enables a three-dimensional description of systems with arbitrary surface textures. We present redistribution matrices for 3D surface textures, including pyramidal textures, binary crossed gratings and a Lambertian scatterer. The results of the OPTOS simulations for silicon sheets with different combinations of these surfaces are in accordance with both optical measurements and results based on established simulation methods like ray tracing. Using OPTOS, we show that the integration of a diffractive grating at the rear side of a silicon solar cell featuring a pyramidal front side results in absorption close to the Yablonovitch Limit enhancing the photocurrent density by 0.6 mA/cm2 for a 200 µm thick cell.

  17. Study on 3-D simulation of flow and turbidity in an oxbow lake in tidal compartment

    NASA Astrophysics Data System (ADS)

    Yokoyama, H.; Momonoe, H.; Hamamoto, S.

    2010-12-01

    We aimed to make flow and turbidity simulation model for an oxbow lake in tidal compartment. The oxbow has two bottle-necks and inflow river from urban district. Bed topography of the oxbow is former meandering channel of large-basin river. Therefore characteristic of flow and water quality is complex. First, field observation was conducted to clarify the characteristics of flow and water quality in the oxbow. From observation results, flow and resuspension phenomena in the oxbow were affected by wind and tide, and the balance of the two factors changed longitudinally. Next, we built 3-D simulation model of flow which took account of the field observation results. In order to investigate effective water quality improvement, we set some test cases: condition of wind, inflow river were changed. From the simulation results, tide was the most important factor, however at the upper part of the oxbow, where the tidal power seemed to be weaker, flow and turbidity were clearly affected by the wind.

  18. Kinematic ground motion simulations on rough faults including effects of 3D stochastic velocity perturbations

    USGS Publications Warehouse

    Graves, Robert; Pitarka, Arben

    2016-01-01

    We describe a methodology for generating kinematic earthquake ruptures for use in 3D ground‐motion simulations over the 0–5 Hz frequency band. Our approach begins by specifying a spatially random slip distribution that has a roughly wavenumber‐squared fall‐off. Given a hypocenter, the rupture speed is specified to average about 75%–80% of the local shear wavespeed and the prescribed slip‐rate function has a Kostrov‐like shape with a fault‐averaged rise time that scales self‐similarly with the seismic moment. Both the rupture time and rise time include significant local perturbations across the fault surface specified by spatially random fields that are partially correlated with the underlying slip distribution. We represent velocity‐strengthening fault zones in the shallow (<5  km) and deep (>15  km) crust by decreasing rupture speed and increasing rise time in these regions. Additional refinements to this approach include the incorporation of geometric perturbations to the fault surface, 3D stochastic correlated perturbations to the P‐ and S‐wave velocity structure, and a damage zone surrounding the shallow fault surface characterized by a 30% reduction in seismic velocity. We demonstrate the approach using a suite of simulations for a hypothetical Mw 6.45 strike‐slip earthquake embedded in a generalized hard‐rock velocity structure. The simulation results are compared with the median predictions from the 2014 Next Generation Attenuation‐West2 Project ground‐motion prediction equations and show very good agreement over the frequency band 0.1–5 Hz for distances out to 25 km from the fault. Additionally, the newly added features act to reduce the coherency of the radiated higher frequency (f>1  Hz) ground motions, and homogenize radiation‐pattern effects in this same bandwidth, which move the simulations closer to the statistical characteristics of observed motions as illustrated by comparison with recordings from

  19. Tropical Oceanic Precipitation Processes over Warm Pool: 2D and 3D Cloud Resolving Model Simulations

    NASA Technical Reports Server (NTRS)

    Tao, W.- K.; Johnson, D.

    1998-01-01

    stratiform regions; (3) the cloud (upward-downward) mass fluxes in convective and stratiform regions; (4) characteristics of clouds (such as cloud size, updraft intensity and cloud lifetime) and the comparison of clouds with Radar observations. Differences and similarities in organization of convection between simulated 2D and 3D cloud systems. Preliminary results indicated that there is major differences between 2D and 3D simulated stratiform rainfall amount and convective updraft and downdraft mass fluxes.

  20. Simulated Microgravity and 3D Culture Enhance Induction, Viability, Proliferation and Differentiation of Cardiac Progenitors from Human Pluripotent Stem Cells

    PubMed Central

    Jha, Rajneesh; Wu, Qingling; Singh, Monalisa; Preininger, Marcela K.; Han, Pengcheng; Ding, Gouliang; Cho, Hee Cheol; Jo, Hanjoong; Maher, Kevin O.; Wagner, Mary B.; Xu, Chunhui

    2016-01-01

    Efficient generation of cardiomyocytes from human pluripotent stem cells is critical for their regenerative applications. Microgravity and 3D culture can profoundly modulate cell proliferation and survival. Here, we engineered microscale progenitor cardiac spheres from human pluripotent stem cells and exposed the spheres to simulated microgravity using a random positioning machine for 3 days during their differentiation to cardiomyocytes. This process resulted in the production of highly enriched cardiomyocytes (99% purity) with high viability (90%) and expected functional properties, with a 1.5 to 4-fold higher yield of cardiomyocytes from each undifferentiated stem cell as compared with 3D-standard gravity culture. Increased induction, proliferation and viability of cardiac progenitors as well as up-regulation of genes associated with proliferation and survival at the early stage of differentiation were observed in the 3D culture under simulated microgravity. Therefore, a combination of 3D culture and simulated microgravity can be used to efficiently generate highly enriched cardiomyocytes. PMID:27492371

  1. Comparison of simulated and experimental 3D laser images using a GmAPD array: application to long range detection

    NASA Astrophysics Data System (ADS)

    Coyac, Antoine; Riviere, Nicolas; Hespel, Laurent; Briottet, Xavier

    2016-05-01

    In this paper, we show the feasibility and the benefit to use a Geiger-mode Avalanche Photo-Diode (GmAPD) array for long range detection, up to several kilometers. A simulation of a Geiger detection sensor is described, which is a part of our end-to-end laser simulator, to generate simulated 3D laser images from synthetic scenes. Resulting 3D point clouds have been compared to experimental acquisitions, performed with our GmAPD 3D camera on similar scenarios. An operational case of long range detection is presented: a copper cable outstretched above the ground, 1 kilometer away the experimental system and with a horizontal line-of-sight (LOS). The detection of such a small object from long distance observation strongly suggests that GmAPD focal plane arrays could be easily used for real-time 3D mapping or surveillance applications from airborne platforms, with good spatial and temporal resolutions.

  2. Suitable Conditions of Reservoir Simulation for Searching Rule Curves

    NASA Astrophysics Data System (ADS)

    Kangrang, Anongrit; Chaleeraktrakoon, Chavalit

    The objective of this study is to carry out a suitable length of inflow record using in the simulation model. The second objective is to find an effect of initial reservoir capacity of reservoir simulation for searching the optimal rule curves. The reservoir simulation model was connected with genetic algorithms to search the optimal rule curves quickly. The model has been applied to determine the optimal rule curves of the Bhumibol and Sirikit Reservoirs (the Chao Phraya River Basin, Thailand). The optimal rule curves of each condition were used to assess by a Monte Carlo simulation. The results show that the shortest period of dry inflow record using in the simulation model in order to search the optimal rule curves is 10 year. Furthermore, the minimum initial capacity of reservoir for searching optimal rule curves is 10% of full capacity.

  3. Compositional and black oil reservoir simulation

    SciTech Connect

    Coats, K.H.; Thomas, L.K.; Pierson, R.G.

    1995-12-31

    This paper describes a three-dimensional, three-phase reservoir simulation model for black oil and compositional applications. Both IMPES and fully implicit formulations are included. The model`s use of a relaxed volume balance concept effectively conserves both mass and volume and reduces Newton iterations. A new implicit well rate calculation method improves IMPES stability. It approximates wellbore crossflow effects with high efficiency and relative simplicity in both IMPES and fully implicit formulations. Multiphase flow in the tubing and near-well turbulent gas flow effects are treated implicitly. Initial saturations are calculated as a function of water-oil and gas-oil capillary pressures which are optimally dependent upon the Leverett J function or initial saturations may be entered as data arrays. A normalization of the relative permeability and capillary pressure curves is used to calculate these terms as a function of rock type and grid block residual saturations. Example problems are presented, including several of the SPE Comparative Solution problems and field simulations. 48 refs.

  4. Role of 3D photo-resist simulation for advanced technology nodes

    NASA Astrophysics Data System (ADS)

    Narayana Samy, Aravind; Seltmann, Rolf; Kahlenberg, Frank; Schramm, Jessy; Küchler, Bernd; Klostermann, Ulrich

    2013-04-01

    3D Resist Models are gaining significant interest for advanced technology node development. Correct prediction of resist profiles, resist top-loss and top-rounding are acquiring higher importance in ORC hotspot verification due to impact on etch resistance and post etch results. We would like to highlight the specific calibration procedure to calibrate a rigorous 3D model. Special focus is on the importance of high quality metrology data for both a successful calibration and for allowing a reduction of the number of data points used for calibration [1]. In a productive application the calibration could be performed using a subset of 20 features measured through dose and focus and model validation was done with 500 features through dose and focus. This data reduction minimized the actual calibration effort of the 3D resist model and enabled calibration run times of less than one hour. The successful validation with the complete data set showed that the data reduction did not cause over- fitting of the model. The model is applied and verified at hotspots showing defects such as bottom bridging or top loss that would not be visible in a 2D resist model. The model performance is also evaluated with a conventional CD error metric where CD at Bottom of simulation and measurement are compared. We could achieve excellent results for both metrics using SEM CD, SEM images, AFM measurements and wafer cross sections. Additional modeling criterion is resist model portability. A prerequisite is the separability of resist model and optical model, i.e. the resist model shall characterize the resist only and should not lump characteristics from the optical model. This is a requirement to port the resist model to different optical setups such as another illumination source without the need of re-calibration. Resist model portability is shown by validation and application of the model to a second process with significantly different optical settings. The resist model can predict hot

  5. Compressible magma/mantle dynamics: 3-D, adaptive simulations in ASPECT

    NASA Astrophysics Data System (ADS)

    Dannberg, Juliane; Heister, Timo

    2016-12-01

    Melt generation and migration are an important link between surface processes and the thermal and chemical evolution of the Earth's interior. However, their vastly different timescales make it difficult to study mantle convection and melt migration in a unified framework, especially for 3-D global models. And although experiments suggest an increase in melt volume of up to 20 per cent from the depth of melt generation to the surface, previous computations have neglected the individual compressibilities of the solid and the fluid phase. Here, we describe our extension of the finite element mantle convection code ASPECT that adds melt generation and migration. We use the original compressible formulation of the McKenzie equations, augmented by an equation for the conservation of energy. Applying adaptive mesh refinement to this type of problems is particularly advantageous, as the resolution can be increased in areas where melt is present and viscosity gradients are high, whereas a lower resolution is sufficient in regions without melt. Together with a high-performance, massively parallel implementation, this allows for high-resolution, 3-D, compressible, global mantle convection simulations coupled with melt migration. We evaluate the functionality and potential of this method using a series of benchmarks and model setups, compare results of the compressible and incompressible formulation, and show the effectiveness of adaptive mesh refinement when applied to melt migration. Our model of magma dynamics provides a framework for modelling processes on different scales and investigating links between processes occurring in the deep mantle and melt generation and migration. This approach could prove particularly useful applied to modelling the generation of komatiites or other melts originating in greater depths. The implementation is available in the Open Source ASPECT repository.

  6. High speed and flexible PEB 3D diffusion simulation based on Sylvester equation

    NASA Astrophysics Data System (ADS)

    Lin, Pei-Chun; Chen, Charlie Chung-Ping

    2013-04-01

    Post exposure bake (PEB) Diffusion effect is one of the most difficult issues in modeling chemically amplified resists. These model equations result in a system of nonlinear partial differential equations describing the time rate of change reaction and diffusion. Verifying such models are difficult, so numerical simulations are needed to solve the model equations. In this paper, we propose a high speed 3D resist image simulation algorithm based on a novel method to solve the PEB Diffusion equation. Our major discovery is that the matrix formulation of the diffusion equation under the Crank- Nicolson scheme can be derived into a special form, AX+XB=C, where the X matrix is a 3D resist image after diffusion effect, A and B matrices contain the diffusion coefficients and the space relationship between directions x, y and z. These matrices are sparse, symmetric and diagonal dominant. The C matrix is the last time-step resist image. The Sylvester equation can be reduced to another form as (I⊗A + BT⊗I) X =C, in which the operator ⊗ is the Kronecker product notation. Compared with a traditional convolution method, our method is more useful in a way that boundary conditions can be more flexible. From our experimental results, we see that the error of the convolution method can be as high as 30% at borders of the design pattern. Furthermore, since the PEB temperature may not be uniform at multi-zone PEB, the convolution method might not be directly applicable in this scenario. Our method is about 20 times faster than the convolution method for a single time step (2 seconds) as illustrated in the attached figure. To simulate 50 seconds of the flexible PEB diffusion process, our method only takes 210 seconds with a convolution set up for a 1240×1240 working area. We use the typical 45nm immersion lithography in our work. The exposure wavelength is set to 193nm; the NA is 1.3775; and the diffusion coefficient is 1.455×10-17m2/s at PEB temperature 150°C along with PEB

  7. Secondary reconnection, energisation and turbulence in dipolarisation fronts: results of a 3D kinetic simulation campaign

    NASA Astrophysics Data System (ADS)

    Lapenta, Giovanni; Goldman, Martin; Newman, David; olshevskyi, Vyacheslav; Markidis, Stefano

    2016-04-01

    Dipolarization fronts (DF) are formed by reconnection outflows interacting with the pre-existing environment. These regions are host of important energy exchanges [1], particle acceleration [2] and a complex structure and evolution [3]. Our recent work has investigated these regions via fully kinetic 3D simulations [4]. As reported recently on Nature Physics [3], based on 3D fully kinetic simulations started with a well defined x-line, we observe that in the DF reconnection transitions towards a more chaotic regime. In the fronts an instability devel- ops caused by the local gradients of the density and by the unfavourable acceleration and field line curvature. The consequence is the break up of the fronts in a fashion similar to the classical fluid Rayleigh-Taylor instability with the formation of "fingers" of plasma and embedded magnetic fields. These fingers interact and produce secondary reconnection sites. We present several different diagnostics that prove the existence of these secondary reconnection sites. Each site is surrounded by its own electron diffusion region. At the fronts the ions are generally not magnetized and considerable ion slippage is present. The discovery we present is that electrons are also slipping, forming localized diffusion regions near secondary reconnection sites [1]. The consequence of this discovery is twofold. First, the instability in the fronts has strong energetic implications. We observe that the energy transfer locally is very strong, an order of magnitude stronger than in the "X" line. However, this energy transfer is of both signs as it is natural for a wavy rippling with regions of magnetic to kinetic and regions of kinetic to magnetic energy conversion. Second, and most important for this session, is that MMS should not limit the search for electron diffusion regions to the location marked with X in all reconnection cartoons. Our simulations predict more numerous and perhaps more easily measurable electron diffusion

  8. Effects of inhomogeneity at stagnation in 3D simulations of ICF implosions

    NASA Astrophysics Data System (ADS)

    Appelbe, Brian

    2016-10-01

    The stagnation phase of an ICF implosion is characterized by a hotspot and dense fuel layer that are spatially and temporally inhomogeneous. Perturbation growth during the implosion results in significant asymmetry at stagnation while the hotspot size, density and temperature change rapidly, even in non-igniting capsules. Diagnosing these inhomogeneities is necessary to increase yield in ICF experiments. In this work, 3D radiation hydrodynamic simulations of perturbed indirect drive ICF capsules are carried out using the CHIMERA code. During the stagnation phase a suite of novel and computationally efficient simulation tools are used to produce synthetic time-resolved neutron spectra and images. These tools allow a detailed study of the effects of hotspot inhomogeneities on diagnostic signals. Results show that the burn-averaged ion temperature drops rapidly during thermonuclear burn as the hotspot evolves from a localised, shock-heated region to a more massive, non-uniform plasma. Primary DD and DT neutron spectra show that there is significant residual bulk fluid motion at stagnation, complicating the measurement of ion temperature. Different perturbation modes cause different levels of anisotropic spectra shifts and broadening. However, in all cases the discrepancies between the DD and DT spectra are a reliable indicator of residual motion at stagnation. The simulations are used to examine the relationship between neutron scattering and areal density (ρR). Three measures of areal density are simulated: downscattered neutron ratio, attenuated primary neutron yield and nT backscatter edge. Each of these diagnoses the magnitude and anisotropy of the ρR with varying success, with accuracy decreasing for higher mode perturbations. Contributions to the neutron energy spectra from T +T reactions, secondary DT reactions and deuteron break-up are also evaluated.

  9. Quantification of Ground Motion Reductions by Fault Zone Plasticity with 3D Spontaneous Rupture Simulations

    NASA Astrophysics Data System (ADS)

    Roten, D.; Olsen, K. B.; Cui, Y.; Day, S. M.

    2015-12-01

    We explore the effects of fault zone nonlinearity on peak ground velocities (PGVs) by simulating a suite of surface rupturing earthquakes in a visco-plastic medium. Our simulations, performed with the AWP-ODC 3D finite difference code, cover magnitudes from 6.5 to 8.0, with several realizations of the stochastic stress drop for a given magnitude. We test three different models of rock strength, with friction angles and cohesions based on criteria which are frequently applied to fractured rock masses in civil engineering and mining. We use a minimum shear-wave velocity of 500 m/s and a maximum frequency of 1 Hz. In rupture scenarios with average stress drop (~3.5 MPa), plastic yielding reduces near-fault PGVs by 15 to 30% in pre-fractured, low-strength rock, but less than 1% in massive, high quality rock. These reductions are almost insensitive to the scenario earthquake magnitude. In the case of high stress drop (~7 MPa), however, plasticity reduces near-fault PGVs by 38 to 45% in rocks of low strength and by 5 to 15% in rocks of high strength. Because plasticity reduces slip rates and static slip near the surface, these effects can partially be captured by defining a shallow velocity-strengthening layer. We also perform a dynamic nonlinear simulation of a high stress drop M 7.8 earthquake rupturing the southern San Andreas fault along 250 km from Indio to Lake Hughes. With respect to the viscoelastic solution (a), nonlinearity in the fault damage zone and in near-surface deposits would reduce long-period (> 1 s) peak ground velocities in the Los Angeles basin by 15-50% (b), depending on the strength of crustal rocks and shallow sediments. These simulation results suggest that nonlinear effects may be relevant even at long periods, especially for earthquakes with high stress drop.

  10. Characteristic wavefield in an experimental rock sample inferred from a 3D FDM simulation

    NASA Astrophysics Data System (ADS)

    Yoshimitsu, N.; Furumura, T.; Maeda, T.

    2014-12-01

    We investigate the origin of wave packets in elastic waves propagate through a rock sample based on a 3D finite difference method (FDM) simulation. Though direct waves of the transmitted waves have been applied to estimate the internal structure of a rock sample, later part of the waveforms did not utilized because their origin were unclear. Understanding the reflection and conversion effect in a rock sample would help to retrieve more information from whole waveform as with the analysis in natural fields. We numerically simulated the elastic wave propagation in a medium model which covers a cylindrical shape of a rock sample. The model was discretized into 1024 x 1024 x 2048 grid points with an interval of 54 micrometer in horizontal direction and 60 micrometer in vertical direction. The density, P wave velocity, and S wave velocity of the each grid point are assumed to be proportional to the X-ray absorption coefficient derived from the micro focus X-ray CT images of a Westery granite sample. We applied a single point force on the boundary of the model sample which mimics realistic transducer movement. The wave propagation movie obtained from the numerical simulation shows very complicated wavefield in a rock sample. Because a rock sample is small and closed, once waves are radiated, they were trapped in the sample by repeating reflection and conversion. Many reflected waves which followed by the converted waves were generated at the sample side surface as well as the upper and lower end. The phase with the largest amplitude propagate along the curved boundary was detected as Rayleigh wave from the particle motions on the sample side surface. Additionally, the surface waves were observed not only in the horizontal section but also in the vertical section. Our simulation indicated that the later phases of the transmitted waves are highly affected by the sample boundary. In order to extract accurate interior information from the transmitted waves, elimination

  11. Multigrid direct numerical simulation of the whole process of flow transition in 3-D boundary layers

    NASA Technical Reports Server (NTRS)

    Liu, Chaoqun; Liu, Zhining

    1993-01-01

    A new technology was developed in this study which provides a successful numerical simulation of the whole process of flow transition in 3-D boundary layers, including linear growth, secondary instability, breakdown, and transition at relatively low CPU cost. Most other spatial numerical simulations require high CPU cost and blow up at the stage of flow breakdown. A fourth-order finite difference scheme on stretched and staggered grids, a fully implicit time marching technique, a semi-coarsening multigrid based on the so-called approximate line-box relaxation, and a buffer domain for the outflow boundary conditions were all used for high-order accuracy, good stability, and fast convergence. A new fine-coarse-fine grid mapping technique was developed to keep the code running after the laminar flow breaks down. The computational results are in good agreement with linear stability theory, secondary instability theory, and some experiments. The cost for a typical case with 162 x 34 x 34 grid is around 2 CRAY-YMP CPU hours for 10 T-S periods.

  12. Comparison of two different surfaces for 3d model abstraction in support of remote sensing simulations

    SciTech Connect

    Pope, Paul A; Ranken, Doug M

    2010-01-01

    A method for abstracting a 3D model by shrinking a triangular mesh, defined upon a best fitting ellipsoid surrounding the model, onto the model's surface has been previously described. This ''shrinkwrap'' process enables a semi-regular mesh to be defined upon an object's surface. This creates a useful data structure for conducting remote sensing simulations and image processing. However, using a best fitting ellipsoid having a graticule-based tessellation to seed the shrinkwrap process suffers from a mesh which is too dense at the poles. To achieve a more regular mesh, the use of a best fitting, subdivided icosahedron was tested. By subdividing each of the twenty facets of the icosahedron into regular triangles of a predetermined size, arbitrarily dense, highly-regular starting meshes can be created. Comparisons of the meshes resulting from these two seed surfaces are described. Use of a best fitting icosahedron-based mesh as the seed surface in the shrinkwrap process is preferable to using a best fitting ellipsoid. The impacts to remote sensing simulations, specifically generation of synthetic imagery, is illustrated.

  13. Pelton turbine Needle erosion prediction based on 3D three- phase flow simulation

    NASA Astrophysics Data System (ADS)

    Chongji, Z.; Yexiang, X.; Wei, Z.; Yangyang, Y.; Lei, C.; Zhengwei, W.

    2014-03-01

    Pelton turbine, which applied to the high water head and small flow rate, is widely used in the mountainous area. During the operation period the sediment contained in the water does not only induce the abrasion of the buckets, but also leads to the erosion at the nozzle which may damage the needle structure. The nozzle and needle structure are mainly used to form high quality cylindrical jet and increase the efficiency of energy exchange in the runner to the most. Thus the needle erosion will lead to the deformation of jet, and then may cause the efficiency loss and cavitation. The favourable prediction of abrasion characteristic of needle can effectively guide the optimization design and maintenance of needle structure. This paper simulated the unsteady three-dimensional multi-phase flow in the nozzle and injected jet flow. As the jet containing water and sediment is injected into the free atmosphere air with high velocity, the VOF model was adopted to predict the water and air flow. The sediment is simplified into round solid particle and the discrete particle model (DPM) was employed to predict the needle abrasion characteristic. The sand particle tracks were analyzed to interpret the mechanism of sand erosion on the needle surface. And the numerical result of needle abrasion was obtained and compared with the abrasion field observation. The similarity of abrasion pattern between the numerical results and field observation illustrated the validity of the 3D multi-phase flow simulation method.

  14. 3D SIMULATIONS OF REALISTIC POWER HALOS IN MAGNETOHYDROSTATIC SUNSPOT ATMOSPHERES: LINKING THEORY AND OBSERVATION

    SciTech Connect

    Rijs, Carlos; Przybylski, Damien; Moradi, Hamed; Cally, Paul S.; Shelyag, Sergiy; Rajaguru, S. P.

    2016-01-20

    The well-observed acoustic halo is an enhancement in time-averaged Doppler velocity and intensity power with respect to quiet-Sun values that is prominent for the weak and highly inclined field around the penumbra of sunspots and active regions. We perform 3D linear wave modeling with realistic distributed acoustic sources in a magnetohydrostatic sunspot atmosphere and compare the resultant simulation enhancements with multiheight SDO observations of the phenomenon. We find that simulated halos are in good qualitative agreement with observations. We also provide further proof that the underlying process responsible for the halo is the refraction and return of fast magnetic waves that have undergone mode conversion at the critical a = c atmospheric layer. In addition, we also find strong evidence that fast Alfvén mode conversion plays a significant role in the structure of the halo, taking energy away from photospheric and chromospheric heights in the form of field-aligned Alfvén waves. This conversion process may explain the observed “dual-ring” halo structure at higher (>8 mHz) frequencies.

  15. EMPulse, a new 3-D simulation code for electromagnetic pulse studies

    NASA Astrophysics Data System (ADS)

    Cohen, Bruce; Eng, Chester; Farmer, William; Friedman, Alex; Grote, David; Kruger, Hans; Larson, David

    2016-10-01

    EMPulse is a comprehensive and modern 3-D simulation code for electro-magnetic pulse (EMP) formation and propagation studies, being developed at LLNL as part of a suite of codes to study E1 EMP originating from prompt gamma rays. EMPulse builds upon the open-source Warp particle-in-cell code framework developed by members of this team and collaborators at other institutions. The goal of this endeavor is a new tool enabling the detailed and self-consistent study of multi-dimensional effects in geometries that have typically been treated only approximately. Here we present an overview of the project, the models and methods that have been developed and incorporated into EMPulse, tests of these models, comparisons to simulations undertaken in CHAP-lite (derived from the legacy code CHAP due to C. Longmire and co-workers), and some approaches to increased computational efficiency being studied within our project. This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Security, LLC, Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  16. Nonlinear 3-D simulation of high-intensity focused ultrasound therapy in the Kidney.

    PubMed

    Suomi, Visa; Jaros, Jiri; Treeby, Bradley; Cleveland, Robin

    2016-08-01

    Kidney cancer is a severe disease which can be treated non-invasively using high-intensity focused ultrasound (HIFU) therapy. However, tissue in front of the transducer and the deep location of kidney can cause significant losses to the efficiency of the treatment. The effect of attenuation, refraction and reflection due to different tissue types on HIFU therapy of the kidney was studied using a nonlinear ultrasound simulation model. The geometry of the tissue was derived from a computed tomography (CT) dataset of a patient which had been segmented for water, bone, soft tissue, fat and kidney. The combined effect of inhomogeneous attenuation and soundspeed was found to result in an 11.0 dB drop in spatial peak-temporal average (SPTA) intensity in the kidney compared to pure water. The simulation without refraction effects showed a 6.3 dB decrease indicating that both attenuation and refraction contribute to the loss in focal intensity. The losses due to reflections at soft tissue interfaces were less than 0.1 dB. Focal point shifting due to refraction effects resulted in -1.3, 2.6 and 1.3 mm displacements in x-, y- and z-directions respectively. Furthermore, focal point splitting into several smaller subvolumes was observed. The total volume of the secondary focal points was approximately 46% of the largest primary focal point. This could potentially lead to undesired heating outside the target location and longer therapy times.

  17. Assessing soil water storage distribution under sprinkler irrigation by coupling 3D simulations and field observations

    NASA Astrophysics Data System (ADS)

    Taha, Uday; Shabeeb, Ahmed; dragonetti, giovanna; Lamaddalena, Nicola; Coppola, Antonio

    2016-04-01

    This work analyzed the variability of sprinkler irrigation application over a bare soil, both in terms of water application efficiency and uniformity, by integrating and comparing the information on the irrigation depth data (ID), as measured by catch cans, soil water storage in the upper root zone, as measured by TDR probes, and a 3D simulations of water flow in soils. Three irrigation tests were performed at three different pressures (2, 3 and 4 bar). A lateral water redistribution was observed and simulated after each irrigation event by comparing spatial distributions of site-specific water application efficiency (AEs), as well as ratios of site-specific actual water storage increase (SWEs) and irrigation depth (IDs) to the water content before irrigation. Because of soil water redistribution processes, distribution uniformity based on soil storages was systematically higher than the catch can uniformity. The obvious consequence of lateral water redistribution processes was that the soil smoothing action on non-uniformity observed at the surface increased both with depth and over time. At a given depth the uniformity of soil water storages always attained the same value, whatever the pressure considered and the catch can-based uniformity coefficient. It was concluded that, for the case of random distribution of ID, the uniformity of water storages is driven by the soil behavior rather than by the irrigation system.

  18. A 3D numerical simulation of different phases of friction stir welding

    NASA Astrophysics Data System (ADS)

    Guerdoux, S.; Fourment, L.

    2009-10-01

    An adaptive arbitrary Lagrangian-Eulerian formulation is developed to compute the material flow and the temperature evolution during the three phases of the friction stir welding (FSW) process. It follows a splitting approach: after the calculations of the velocity/pressure and temperature fields, the mesh velocity is derived from the domain boundary evolution and from an adaptive refinement criterion provided by error estimation, and finally state variables are remapped. In this way, the unilateral contact conditions between the plate and the tool are accurately taken into account, so allowing one to model various instabilities that may occur during the process, such as the role played by the plunge depth of the tool on the formations of flashes, the possible appearance of non-steady voids or tunnel holes and the influence of the threads on the material flow, the temperature field and the welding efforts. This formulation is implemented in the 3D Forge3 FE software with automatic remeshing. The non-steady phases of FSW can so be simulated, as well as the steady welding phase. The study of different process conditions shows that the main phenomena taking place during FSW can be simulated with the right sensitivities.

  19. 3D-Simulation Of Concentration Distributions Inside Large-Scale Circulating Fluidized Bed Combustors

    NASA Astrophysics Data System (ADS)

    Wischnewski, R.; Ratschow, L.; Hartge, E. U.; Werthe, J.

    With increasing size of modern CFB combustors the lateral mixing of fuels and secondary air gains more and more importance. Strong concentration gradients, which result from improper lateral mixing, can lead to operational problems, high flue gas emissions and lower boiler efficiencies. A 3D-model for the simulation of local gas and solids concentrations inside industrial-sized CFB boilers has been developed. The model is based on a macroscopic approach and considers all major mechanisms during fuel spreading and subsequent combustion of char and volatiles. Typical characteristics of modern boilers like staged combustion, a smaller cross-sectional area in the lower section of the combustion chamber and the co-combustion of additional fuels with coal can be considered. The 252 MWth combustor of Stadtwerke Duisburg AG is used for the validation of the model. A comprehensive picture of the local conditions inside the combustion chamber is achieved by the combination of local gas measurements and the three-dimensional simulation of concentration distributions.

  20. Simulations of Coalescence and Breakup of Interfaces Using a 3D Front-tracking Method

    NASA Astrophysics Data System (ADS)

    Lu, Jiacai; Tryggvason, Gretar

    2015-11-01

    Direct Numerical Simulations (DNS) of complex multiphase flows with coalescing and breaking-up of interfaces are conducted using a 3D front-tracking method. Front-tracking method has been successfully used in DNS of turbulent channel bubbly flows and many other multiphase flows, but as the void fraction increases changes in the interface topology, though coalescence and breakup, become more common and have to be accounted for. Topology changes have often been identified as a challenge for front tracking, where the interface is represented using a triangular mesh, but here we present an efficient algorithm to change the topology of triangular elements of interfaces. In the current implementation we have not included any small-scale attractive forces so thin films coalesce either at prescribed times or when their thickness reaches a given value. Simulations of the collisions of two drops and comparisons with experimental results have been used to validate the algorithm but the main applications have been to flow regime transitions in gas-liquid flows in pressure driven channel flows. The evolution of flow, including flow rate, wall shear, projected interface areas, pseudo-turbulence, and the average size of the various flow structures, is examined as the topology of the interface changes through coalescence and breakup. Research supported by DOE (CASL).

  1. Characterization of an SRF gun: a 3D full wave simulation

    SciTech Connect

    Wang, E.; Ben-Zvi, I.; Wang, J.

    2011-03-28

    We characterized a BNL 1.3GHz half-cell SRF gun is tested for GaAs photocathode. The gun already was simulated several years ago via two-dimensional (2D) numerical codes (i.e., Superfish and Parmela) with and without the beam. In this paper, we discuss our investigation of its characteristics using a three dimensional (3D) full-wave code (CST STUDIO SUITE{trademark}).The input/pickup couplers are sited symmetrically on the same side of the gun at an angle of 180{sup o}. In particular, the inner conductor of the pickup coupler is considerably shorter than that of the input coupler. We evaluated the cross-talk between the beam (trajectory) and the signal on the input coupler compared our findings with published results based on analytical models. The CST STUDIO SUITE{trademark} also was used to predict the field within the cavity; particularly, a combination of transient/eigenmode solvers was employed to accurately construct the RF field for the particles, which also includes the effects of the couplers. Finally, we explored the beam's dynamics with a particle in cell (PIC) simulation, validated the results and compare them with 2D code result.

  2. The plasma interaction of Enceladus: 3D hybrid simulations and comparison with Cassini MAG data

    NASA Astrophysics Data System (ADS)

    Kriegel, H.; Simon, S.; Müller, J.; Motschmann, U.; Saur, J.; Glassmeier, K.-H.; Dougherty, M. K.

    2009-12-01

    We study the interaction of Saturn's small, icy moon Enceladus and its plume with the corotating magnetospheric plasma by means of a 3D hybrid simulation model, which treats the ions as individual particles and the electrons as a massless, charge-neutralizing fluid. We analyze systematically how Enceladus' internal conductivity and plasma absorption at the surface as well as charge exchange and pick-up in the plume contribute to the overall structure of the interaction region. Furthermore, we provide a comparison of our simulation results to data obtained by the Cassini magnetometer instrument. The major findings of this study are: (1) the magnetic field diffuses through the solid body of Enceladus almost unaffected, whereas plasma absorption gives rise to a symmetric depletion wake downstream of the moon; (2) due to the small gyroradii of the newly generated plume ions, the pick-up tail possesses a 2D structure; (3) the magnetic field lines drape around the plume, which triggers an Alfvén wing system that dominates the structure of Enceladus' plasma environment. Inside the plume itself, a magnetic cavity is formed; (4) besides the reproduction of the key features of the observed magnetic field signatures, evidence for variability in the locations of the active jets and in the total gas content of the plume are shown.

  3. Modeling dolomitized carbonate-ramp reservoirs: A case study of the Seminole San Andres unit. Part 2 -- Seismic modeling, reservoir geostatistics, and reservoir simulation

    SciTech Connect

    Wang, F.P.; Dai, J.; Kerans, C.

    1998-11-01

    In part 1 of this paper, the authors discussed the rock-fabric/petrophysical classes for dolomitized carbonate-ramp rocks, the effects of rock fabric and pore type on petrophysical properties, petrophysical models for analyzing wireline logs, the critical scales for defining geologic framework, and 3-D geologic modeling. Part 2 focuses on geophysical and engineering characterizations, including seismic modeling, reservoir geostatistics, stochastic modeling, and reservoir simulation. Synthetic seismograms of 30 to 200 Hz were generated to study the level of seismic resolution required to capture the high-frequency geologic features in dolomitized carbonate-ramp reservoirs. Outcrop data were collected to investigate effects of sampling interval and scale-up of block size on geostatistical parameters. Semivariogram analysis of outcrop data showed that the sill of log permeability decreases and the correlation length increases with an increase of horizontal block size. Permeability models were generated using conventional linear interpolation, stochastic realizations without stratigraphic constraints, and stochastic realizations with stratigraphic constraints. Simulations of a fine-scale Lawyer Canyon outcrop model were used to study the factors affecting waterflooding performance. Simulation results show that waterflooding performance depends strongly on the geometry and stacking pattern of the rock-fabric units and on the location of production and injection wells.

  4. 3-D Reservoir and Stochastic Fracture Network Modeling for Enhanced Oil Recovery, Circle Ridge Phosphoria/Tensleep Reservoir, and River Reservation, Arapaho and Shoshone Tribes, Wyoming

    SciTech Connect

    La Pointe, Paul R.; Hermanson, Jan

    2002-09-09

    The goal of this project is to improve the recovery of oil from the Circle Ridge Oilfield, located on the Wind River Reservation in Wyoming, through an innovative integration of matrix characterization, structural reconstruction, and the characterization of the fracturing in the reservoir through the use of discrete fracture network models.

  5. Fully Kinetic 3D Simulations of the Interaction of the Solar Wind with Mercury

    NASA Astrophysics Data System (ADS)

    Amaya, J.; Deca, J.; Lembege, B.; Lapenta, G.

    2015-12-01

    The planet Mercury has been studied by the space mission Mariner 10, in the 1970's, and by the MESSENGER mission launched in 2004. Interest in the first planet of the Solar System has now been renewed by the launch in 2017 of the BepiColombo mission. MESSENGER and BepiColombo give access to information about the local conditions of the magnetosphere of Mercury. This data must be evaluated in the context of the global interaction between the solar wind and the planet's magnetosphere. Global scale simulations of the planet's environment are necessary to fully understand the data gathered from in-situ measurements. We use three-dimensional simulations to support the scientific goals of the two missions. In contrast with the results based on MHD (Kabin et al., 2000) and hybrid codes (Kallio et Janhumen, 2003; Travnicek et al., 2007, 2010; Richer et al., 2012), the present work is based on the implicit moment Particle-in-Cell (PiC) method, which allows to use large time and space steps, while granting access to the dynamics of the smaller electron scales in the plasma. The purpose of these preliminary PIC simulations is to retrieve the top-level features of Mercury's magnetosphere and its frontiers. We compare the results obtained with the implicit moment PiC method against 3D hybrid simulations. We perform simulations of the global plasma environment of Mercury using the solar wind conditions measured by MESSENGER. We show that complex flows form around the planet, including the development of Kelvin-Helmoltz instabilities at the flanks. We evaluate the dynamics of the shock, magnetosheath, magnetopause, the reconnection areas, the formation of plasma sheet and magnetotail, and the variation of ion/electron plasma flows when crossing these frontiers. The simulations also give access to detailed information about the particle dynamics and their velocity distribution at locations that can be used for comparison with data from MESSENGER and later on with the forthcoming

  6. 3D dynamic rupture simulation and local tomography studies following the 2010 Haiti earthquake

    NASA Astrophysics Data System (ADS)

    Douilly, Roby

    The 2010 M7.0 Haiti earthquake was the first major earthquake in southern Haiti in 250 years. As this event could represent the beginning of a new period of active seismicity in the region, and in consideration of how vulnerable the population is to earthquake damage, it is important to understand the nature of this event and how it has influenced seismic hazards in the region. Most significantly, the 2010 earthquake occurred on the secondary Leogâne thrust fault (two fault segments), not the Enriquillo Fault, the major strike-slip fault in the region, despite it being only a few kilometers away. We first use a finite element model to simulate rupture along the Leogâne fault. We varied friction and background stress to investigate the conditions that best explain observed surface deformations and why the rupture did not to jump to the nearby Enriquillo fault. Our model successfully replicated rupture propagation along the two segments of the Leogâne fault, and indicated that a significant stress increase occurred on the top and to the west of the Enriquillo fault. We also investigated the potential ground shaking level in this region if a rupture similar to the Mw 7.0 2010 Haiti earthquake were to occur on the Enriquillo fault. We used a finite element method and assumptions on regional stress to simulate low frequency dynamic rupture propagation for the segment of the Enriquillo fault closer to the capital. The high-frequency ground motion components were calculated using the specific barrier model, and the hybrid synthetics were obtained by combining the low-frequencies ( 1Hz) from the stochastic simulation using matched filtering at a crossover frequency of 1 Hz. The average horizontal peak ground acceleration, computed at several sites of interest through Port-au-Prince (the capital), has a value of 0.35g. Finally, we investigated the 3D local tomography of this region. We considered 897 high-quality records from the earthquake catalog as recorded by

  7. From micro-scale 3D simulations to macro-scale model of periodic porous media

    NASA Astrophysics Data System (ADS)

    Crevacore, Eleonora; Tosco, Tiziana; Marchisio, Daniele; Sethi, Rajandrea; Messina, Francesca

    2015-04-01

    In environmental engineering, the transport of colloidal suspensions in porous media is studied to understand the fate of potentially harmful nano-particles and to design new remediation technologies. In this perspective, averaging techniques applied to micro-scale numerical simulations are a powerful tool to extrapolate accurate macro-scale models. Choosing two simplified packing configurations of soil grains and starting from a single elementary cell (module), it is possible to take advantage of the periodicity of the structures to reduce the computation costs of full 3D simulations. Steady-state flow simulations for incompressible fluid in laminar regime are implemented. Transport simulations are based on the pore-scale advection-diffusion equation, that can be enriched introducing also the Stokes velocity (to consider the gravity effect) and the interception mechanism. Simulations are carried on a domain composed of several elementary modules, that serve as control volumes in a finite volume method for the macro-scale method. The periodicity of the medium involves the periodicity of the flow field and this will be of great importance during the up-scaling procedure, allowing relevant simplifications. Micro-scale numerical data are treated in order to compute the mean concentration (volume and area averages) and fluxes on each module. The simulation results are used to compare the micro-scale averaged equation to the integral form of the macroscopic one, making a distinction between those terms that could be computed exactly and those for which a closure in needed. Of particular interest it is the investigation of the origin of macro-scale terms such as the dispersion and tortuosity, trying to describe them with micro-scale known quantities. Traditionally, to study the colloidal transport many simplifications are introduced, such those concerning ultra-simplified geometry that usually account for a single collector. Gradual removal of such hypothesis leads to a

  8. Validation of 3-D Ice Accretion Measurement Methodology for Experimental Aerodynamic Simulation

    NASA Technical Reports Server (NTRS)

    Broeren, Andy P.; Addy, Harold E., Jr.; Lee, Sam; Monastero, Marianne C.

    2014-01-01

    Determining the adverse aerodynamic effects due to ice accretion often relies on dry-air wind-tunnel testing of artificial, or simulated, ice shapes. Recent developments in ice accretion documentation methods have yielded a laser-scanning capability that can measure highly three-dimensional features of ice accreted in icing wind tunnels. The objective of this paper was to evaluate the aerodynamic accuracy of ice-accretion simulations generated from laser-scan data. Ice-accretion tests were conducted in the NASA Icing Research Tunnel using an 18-inch chord, 2-D straight wing with NACA 23012 airfoil section. For six ice accretion cases, a 3-D laser scan was performed to document the ice geometry prior to the molding process. Aerodynamic performance testing was conducted at the University of Illinois low-speed wind tunnel at a Reynolds number of 1.8 x 10(exp 6) and a Mach number of 0.18 with an 18-inch chord NACA 23012 airfoil model that was designed to accommodate the artificial ice shapes. The ice-accretion molds were used to fabricate one set of artificial ice shapes from polyurethane castings. The laser-scan data were used to fabricate another set of artificial ice shapes using rapid prototype manufacturing such as stereolithography. The iced-airfoil results with both sets of artificial ice shapes were compared to evaluate the aerodynamic simulation accuracy of the laser-scan data. For four of the six ice-accretion cases, there was excellent agreement in the iced-airfoil aerodynamic performance between the casting and laser-scan based simulations. For example, typical differences in iced-airfoil maximum lift coefficient were less than 3% with corresponding differences in stall angle of approximately one degree or less. The aerodynamic simulation accuracy reported in this paper has demonstrated the combined accuracy of the laser-scan and rapid-prototype manufacturing approach to simulating ice accretion for a NACA 23012 airfoil. For several of the ice

  9. Understanding the core-halo relation of quantum wave dark matter from 3D simulations.

    PubMed

    Schive, Hsi-Yu; Liao, Ming-Hsuan; Woo, Tak-Pong; Wong, Shing-Kwong; Chiueh, Tzihong; Broadhurst, Tom; Hwang, W-Y Pauchy

    2014-12-31

    We examine the nonlinear structure of gravitationally collapsed objects that form in our simulations of wavelike cold dark matter, described by the Schrödinger-Poisson (SP) equation with a particle mass ∼10(-22)  eV. A distinct gravitationally self-bound solitonic core is found at the center of every halo, with a profile quite different from cores modeled in the warm or self-interacting dark matter scenarios. Furthermore, we show that each solitonic core is surrounded by an extended halo composed of large fluctuating dark matter granules which modulate the halo density on a scale comparable to the diameter of the solitonic core. The scaling symmetry of the SP equation and the uncertainty principle tightly relate the core mass to the halo specific energy, which, in the context of cosmological structure formation, leads to a simple scaling between core mass (Mc) and halo mass (Mh), Mc∝a(-1/2)Mh(1/3), where a is the cosmic scale factor. We verify this scaling relation by (i) examining the internal structure of a statistical sample of virialized halos that form in our 3D cosmological simulations and by (ii) merging multiple solitons to create individual virialized objects. Sufficient simulation resolution is achieved by adaptive mesh refinement and graphic processing units acceleration. From this scaling relation, present dwarf satellite galaxies are predicted to have kiloparsec-sized cores and a minimum mass of ∼10(8)M⊙, capable of solving the small-scale controversies in the cold dark matter model. Moreover, galaxies of 2×10(12)M⊙ at z=8 should have massive solitonic cores of ∼2×10(9)M⊙ within ∼60  pc. Such cores can provide a favorable local environment for funneling the gas that leads to the prompt formation of early stellar spheroids and quasars.

  10. Canopy polarized BRDF simulation based on non-stationary Monte Carlo 3-D vector RT modeling

    NASA Astrophysics Data System (ADS)

    Kallel, Abdelaziz; Gastellu-Etchegorry, Jean Philippe

    2017-03-01

    Vector radiative transfer (VRT) has been largely used to simulate polarized reflectance of atmosphere and ocean. However it is still not properly used to describe vegetation cover polarized reflectance. In this study, we try to propose a 3-D VRT model based on a modified Monte Carlo (MC) forward ray tracing simulation to analyze vegetation canopy reflectance. Two kinds of leaf scattering are taken into account: (i) Lambertian diffuse reflectance and transmittance and (ii) specular reflection. A new method to estimate the condition on leaf orientation to produce reflection is proposed, and its probability to occur, Pl,max, is computed. It is then shown that Pl,max is low, but when reflection happens, the corresponding radiance Stokes vector, Io, is very high. Such a phenomenon dramatically increases the MC variance and yields to an irregular reflectance distribution function. For better regularization, we propose a non-stationary MC approach that simulates reflection for each sunny leaf assuming that its orientation is randomly chosen according to its angular distribution. It is shown in this case that the average canopy reflection is proportional to Pl,max ·Io which produces a smooth distribution. Two experiments are conducted: (i) assuming leaf light polarization is only due to the Fresnel reflection and (ii) the general polarization case. In the former experiment, our results confirm that in the forward direction, canopy polarizes horizontally light. In addition, they show that in inclined forward direction, diagonal polarization can be observed. In the latter experiment, polarization is produced in all orientations. It is particularly pointed out that specular polarization explains just a part of the forward polarization. Diffuse scattering polarizes light horizontally and vertically in forward and backward directions, respectively. Weak circular polarization signal is also observed near the backscattering direction. Finally, validation of the non

  11. Characterization of double modified internal gate pixel by 3D simulation study

    NASA Astrophysics Data System (ADS)

    Aurola, A.; Marochkin, V.; Tuuva, T.

    2015-01-01

    We have developed a novel detector concept based on Modified Internal Gate Field Effect Transistor (MIGFET) wherein a buried Modified Internal Gate (MIG) is implanted underneath a channel of a FET. In between the MIG and the channel of the FET there is a depleted semiconductor material forming a potential barrier between charges in the channel and similar type signal charges located in the MIG. The signal charges in the MIG have a measurable effect on the conductance of the channel. In this paper a double MIGFET pixel is investigated comprising two MIGFETs. By transferring the signal charges between the two MIGs Non-Destructive Correlated Double Sampling Readout (NDCDSR) is enabled. The proposed MIG radiation detector suits particularly well for low-light-level imaging, X-ray spectroscopy, as well as synchrotron and X-ray Free Electron Laser (XFEL) facilities. The reason for the excellent X-ray detection performance stems from the fact that interface related issues can be considerably mitigated since interface generated dark noise can be completely avoided and interface generated 1/f and Random Telegraph Signal (RTS) noise can be considerably reduced due to a deep buried channel readout configuration. Electrical parameters of the double MIGFET pixel have been evaluated by 3D TCAD simulation study. Simulation results show the absence of interface generated dark noise, significantly reduced interface generated 1/f and RTS noise, well performing NDCDSR operation, and blooming protection due to an inherent vertical anti-blooming structure. In addition, the backside illuminated thick fully depleted pixel design provides a homogeneous radiation entry window, low crosstalk due to lack of diffusion, and good quantum efficiency for low energy X-rays and NIR light. These facts result in excellent Signal-to-Noise Ratio (SNR) and very low crosstalk enabling thus excellent X-ray energy and spatial resolution. The simulation demonstrates the charge to current conversion gain for

  12. Application of a delumping procedure to compositional reservoir simulations

    SciTech Connect

    Stenby, E.H.; Christensen, J.R.; Knudsen, K.; Leibovici, C.

    1996-12-31

    Characterization and lumping are always performed when dealing with reservoir fluids. The number of pseudocomponents in a compositional reservoir simulation is normally between three and eight. In order to optimize the reservoir performance, it is necessary to know a detailed composition of the product stream from the reservoir. This paper deals with the problems of how to come from the lumped system (for which the reservoir simulation was performed) to a description of the full system (which is important in order to optimize the down-stream facilities). The equations of the delumping procedure are shown and the application of the method is illustrated through examples, including a constant volume depletion experiment and the fifth SPE Comparative example with a fluid description from a North Sea reservoir (with the calculated composition after a lumping, an experiment and a delumping).

  13. Software Development: 3D Animations and Creating User Interfaces for Realistic Simulations

    NASA Technical Reports Server (NTRS)

    Gordillo, Orlando Enrique

    2015-01-01

    My fall 2015 semester was spent at the Lyndon B. Johnson Space Center working in the Integrated Graphics, Operations, and Analysis Laboratory (IGOAL). My first project was to create a video animation that could tell the story of OMICS. OMICS is a term being used in the field of biomedical science to describe the collective technologies that study biological systems, such as what makes up a cell and how it functions with other systems. In the IGOAL I used a large 23 inch Wacom monitor to draw storyboards, graphics, and line art animations. I used Blender as the 3D environment to sculpt, shape, cut or modify the several scenes and models for the video. A challenge creating this video was to take a term used in biomedical science and describe it in such a way that an 8th grade student can understand. I used a line art style because it would visually set the tone for what we thought was an educational style. In order to get a handle on the perspective and overall feel for the animation without overloading my workspace, I split up the 2 minute animation into several scenes. I used Blender's python scripting capabilities which allowed for the addition of plugins to add or modify tools. The scripts can also directly interact with the objects to create naturalistic patterns or movements. After collecting the rendered scenes, I used Blender's built-in video editing workspace to output the animation. My second project was to write software that emulates a physical system's interface. The interface was to simulate a boat, ROV, and winch system. Simulations are a time and cost effective way to test complicated data and provide training for operators without having to use expensive hardware. We created the virtual controls with 3-D Blender models and 2-D graphics, and then add functionality in C# using the Unity game engine. The Unity engine provides several essential behaviors of a simulator, such as the start and update functions. A framework for Unity, which was developed in

  14. 3-D Direct Simulation Monte Carlo modeling of comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Liao, Y.; Su, C.; Finklenburg, S.; Rubin, M.; Ip, W.; Keller, H.; Knollenberg, J.; Kührt, E.; Lai, I.; Skorov, Y.; Thomas, N.; Wu, J.; Chen, Y.

    2014-07-01

    After deep-space hibernation, ESA's Rosetta spacecraft has been successfully woken up and obtained the first images of comet 67P /Churyumov-Gerasimenko (C-G) in March 2014. It is expected that Rosetta will rendezvous with comet 67P and start to observe the nucleus and coma of the comet in the middle of 2014. As the comet approaches the Sun, a significant increase in activity is expected. Our aim is to understand the physical processes in the coma with the help of modeling in order to interpret the resulting measurements and establish observational and data analysis strategies. DSMC (Direct Simulation Monte Carlo) [1] is a very powerful numerical method to study rarefied gas flows such as cometary comae and has been used by several authors over the past decade to study cometary outflow [2,3]. Comparisons between DSMC and fluid techniques have also been performed to establish the limits of these techniques [2,4]. The drawback with 3D DSMC is that it is computationally highly intensive and thus time consuming. However, the performance can be dramatically increased with parallel computing on Graphic Processor Units (GPUs) [5]. We have already studied a case with comet 9P/Tempel 1 where the Deep Impact observations were used to define the shape of the nucleus and the outflow was simulated with the DSMC approach [6,7]. For comet 67P, we intend to determine the gas flow field in the innermost coma and the surface outgassing properties from analyses of the flow field, to investigate dust acceleration by gas drag, and to compare with observations (including time variability). The boundary conditions are implemented with a nucleus shape model [8] and thermal models which are based on the surface heat-balance equation. Several different parameter sets have been investigated. The calculations have been performed using the PDSC^{++} (Parallel Direct Simulation Monte Carlo) code [9] developed by Wu and his coworkers [10-12]. Simulation tasks can be accomplished within 24

  15. Numerical Simulation of the Effect of 3D Needle Movement on Cavitation and Spray Formation in a Diesel Injector

    NASA Astrophysics Data System (ADS)

    Mandumpala Devassy, B.; Edelbauer, W.; Greif, D.

    2015-12-01

    Cavitation and its effect on spray formation and its dispersion play a crucial role in proper engine combustion and controlled emission. This study focuses on these effects in a typical common rail 6-hole diesel injector accounting for 3D needle movement and flow compressibility effects. Coupled numerical simulations using 1D and 3D CFD codes are used for this investigation. Previous studies in this direction have already presented a detailed structure of the adopted methodology. Compared to the previous analysis, the present study investigates the effect of 3D needle movement and cavitation on the spray formation for pilot and main injection events for a typical diesel engine operating point. The present setup performs a 3D compressible multiphase simulation coupled with a standalone 1D high pressure flow simulation. The simulation proceeds by the mutual communication between 1D and 3D solvers. In this work a typical common rail injector with a mini-sac nozzle is studied. The lateral and radial movement of the needle and its effect on the cavitation generation and the subsequent spray penetration are analyzed. The result indicates the effect of compressibility of the liquid on damping the needle forces, and also the difference in the spray penetration levels due to the asymmetrical flow field. Therefore, this work intends to provide an efficient and user-friendly engineering tool for simulating a complete fuel injector including spray propagation.

  16. A general formulation for compositional reservoir simulation

    SciTech Connect

    Rodriguez, F.; Guzman, J.; Galindo-Nava, A. |

    1994-12-31

    In this paper the authors present a general formulation to solve the non-linear difference equations that arise in compositional reservoir simulation. The general approach here presented is based on newton`s method and provides a systematic approach to generate several formulations to solve the compositional problem, each possessing a different degree of implicitness and stability characteristics. The Fully-Implicit method is at the higher end of the implicitness spectrum while the IMPECS method, implicit in pressure-explicit in composition and saturation, is at the lower end. They show that all methods may be obtained as particular cases of the fully-implicit method. Regarding the matrix problem, all methods have a similar matrix structure; the composition of the Jacobian matrix is however unique in each case, being in some instances amenable to reductions for optimal solution of the matrix problem. Based on this, a different approach to derive IMPECS type methods is proposed; in this case, the whole set of 2nc + 6 equations, that apply in each gridblock, is reduced to a single pressure equation through matrix reduction operations; this provides a more stable numerical scheme, compared to other published IMPCS methods, in which the subset of thermodynamic equilibrium equations is arbitrarily decoupled form the set of gridblock equations to perform such reduction. The authors discuss how the general formulation here presented can be used to formulate and construct an adaptive-implicit compositional simulators. They also present results on the numerical performance of FI, IMPSEC and IMPECS methods on some test problems.

  17. [Size dependent SERS activity of gold nanoparticles studied by 3D-FDTD simulation].

    PubMed

    Li, Li-mei; Fang, Ping-ping; Yang, Zhi-lin; Huang, Wen-da; Wu, De-yin; Ren, Bin; Tian, Zhong-qun

    2009-05-01

    By synthesizing Au nanoparticles with the controllable size from about 16 to 160 nm and measuring their SERS activity, the authors found that Au nanoparticles film with a size in the range of 120-135 nm showed the highest SERS activity with the 632.8 nm excitation, which is different from previous experimental results and theoretical predictions. The three dimensional finite difference time domain (3D-FDTD)method was employed to simulate the size dependent SERS activity. At the 632.8 nm excitation, the particles with a size of 110 nm shows the highest enhancement under coupling condition and presents an enhancement as high as 10(9) at the hot site. If the enhancement is averaged over the whole surface, the enhancement can still be as high as 10(7), in good agreement with our experimental data. For Au nanoparticles with a larger size such as 220 nm, the multipolar effect leads to the appearance of the second maximum enhancement with the increase in particles size. The averaged enhancement for the excitation line of 325 nm is only 10(2).

  18. 3D Simulation of the Growth of Alloy Semiconductor Quantum Dots Considering Morphological and Compositional Coupling

    NASA Astrophysics Data System (ADS)

    Guo, Junyan; Zhang, Yong-Wei; Narayanaswamy, Sridhar

    2012-02-01

    Fabrication of quantum dots (QDs) with high density may be realized by self-assembly via heteroepitaxial growth of thin films. Since the electronic and optoelectronic properties of QDs are sensitive to size, morphology, strain and especially composition, it is of great importance to control their composition profiles and morphology, and engineer the strain in them. Since the growth is a dynamic process, which carries out via surface diffusion driven primarily by strain relaxation and entropy change due to chemical intermixing, a strong coupling between morphological and composition evolutions during this process leads to a rather complex dynamics, which has not been fully understood. In this work, a 3-D finite element model is developed, which is capable of modeling the formation, self-assembly and coarsening of hetero-epitaxial alloy islands by considering the coupling of morphological and compositional evolution. Several interesting experimental observations, such as fast coarsening kinetics; asymmetries in composition profile and island shape; lateral motion of alloy islands have been observed in our simulations. Our model predictions have painted a rather complete picture for the entire dynamic evolution during the growth of nanoscale heteroepitaxial islands.

  19. Simulation study of a novel 3D SPAD pixel in an advanced FD-SOI technology

    NASA Astrophysics Data System (ADS)

    Vignetti, M. M.; Calmon, F.; Lesieur, P.; Savoy-Navarro, A.

    2017-02-01

    In this paper, a novel SPAD architecture implemented in a Fully-Depleted Silicon-On-Insulator (SOI) CMOS technology is presented. Thanks to its intrinsic vertical 3D structure, the proposed solution is expected to allow further scaling of the pixel size while ensuring high fill factors. Moreover the pixel and the detector electronics can benefit of the well-known advantages brought by SOI technology with respect to bulk CMOS, such as higher speed and lower power consumption. TCAD simulations based on realistic process parameters and dedicated post-processing analysis are carried out in order to optimize and validate the avalanche diode architecture for an optimal electric field distribution in the device but also to extract the main parameters of the SPAD, such as the breakdown voltage, the avalanche triggering probability, the dark count rate and the photon detection probability. A comparison between the efficiency in back-side and front-side approaches is carried out with a particular focus on time-of-flight applications.

  20. Accretion to magnetized stars through the Rayleigh-Taylor instability: global 3D simulations