Lerche, I. )
1989-01-01
The exploration for oil is a high-risk game. Worldwide drilling success is around 5-10%, the average cost of drilling is around $1000 a foot, and the average well is now around 15,000 feet deep. Over the years, two fundamental avenues of attack have been developed: methods designed to locate oil in situ from direct measurement ahead of the drill and methods focusing on the dynamic evolution of a sedimentary basin in relation to the timing of hydrocarbon generation, migration, and accumulation to provide an assessment of which areas in a basin might be the most prospective for oil accumulations today. This volume addresses the problem of quantitative basin analysis in relation to oil accumulations. Emphasis is placed on the uncertainties and resolution limits of basin analysis given constraints derived from surface and downhole data and the sensitivity to model input parameters and assumptions.
Porten, D.R.; Crowe, R.D.
1994-12-16
The purpose of this accident safety analysis is to document in detail, analyses whose results were reported in summary form in the K Basins Safety Analysis Report WHC-SD-SNF-SAR-001. The safety analysis addressed the potential for release of radioactive and non-radioactive hazardous material located in the K Basins and their supporting facilities. The safety analysis covers the hazards associated with normal K Basin fuel storage and handling operations, fuel encapsulation, sludge encapsulation, and canister clean-up and disposal. After a review of the Criticality Safety Evaluation of the K Basin activities, the following postulated events were evaluated: Crane failure and casks dropped into loadout pit; Design basis earthquake; Hypothetical loss of basin water accident analysis; Combustion of uranium fuel following dryout; Crane failure and cask dropped onto floor of transfer area; Spent ion exchange shipment for burial; Hydrogen deflagration in ion exchange modules and filters; Release of Chlorine; Power availability and reliability; and Ashfall.
WEBB, R.H.
1999-12-29
This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Safety Analysis Report (HNF-SD-WM-SAR-062, Rev.4). This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report.
PECH, S.H.
2000-08-23
This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Final Safety Analysis Report. This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report.
NASA Astrophysics Data System (ADS)
Guyennon, N.; Valerio, G.; Salerno, F.; Pilotti, M.; Tartari, G.; Copetti, D.
2014-09-01
The internal wave-field of a Y-shaped lake (Lake Como, North Italy) was investigated over a 3-year long period applying wavelet time-frequency analysis to temperature and wind data time series, recorded at the edge of each of the three arms. The comparison with the results from a modal model allowed to identify the presence of both first and second vertical modes of oscillations. The field data analysis underlined a heterogeneous baroclinic response with the eastern arm decoupled from the remaining part of the lake constituted by the northern and western arms (north-south west transect). This disjoined response is expected to enhance the water exchange between the northern and the western arm, with relevant consequences on the inter-basins water exchanges and on the distribution of chemical and biological species. In the north-south west transect the analysis of the low power signals in winter underlined a residual internal wave activity ascribed to the first vertical free mode of oscillation (V1H1).
Morgan, D.S.; Jones, J.L.
1996-01-01
A numerical ground-water flow model of a hypothetical basin was constructed and used to investigate the effects of ground-water withdrawals on rates of natural discharge to streams and springs in small basins of the Puget Sound Lowland. Definitions of the topography, geology, drainage, and climate of the hypothetical basin were based on the features of typical small basins in the Puget Sound Lowland. This information was used to construct a 13-layer numerical ground-water flow model capable of simulating water levels, hydraulic gradients, and discharge to streams and springs. Three sequences of glacial drift and interglacial deposits were simulated in the model; each sequence consisted of recessional outwash, till, advance, outwash, and fine-grained interglacial sediments. Alluvial sediments of the major stream valleys and undifferentiated glacial and interglacial deposits were also included in the model. The model was calibrated by comparing simulated hydrologic conditions with expected conditions and making adjustments to values of hydraulic characteristics as needed. The model was calibrated to predevelop- ment conditions (those prior to pumping), and then used to simulate the effects of pumping on natural discharge to streams and springs. Seven series of simulations were made to investigate the effects of (1) distance from the well to a stream, (2) the presence of confining layers, (3) pumping rate, (4) depth of the pumped aquifer, (5) distance from the well to a bluff, (6) well density, and (7) recharge rate. The discharge of wells pumping from unconfined outwash aquifers on the drift plains is derived almost entirely from capture of natural discharge to nearby stream reaches. Increasing the lateral distance between the well and stream caused more of the well discharge to be captured from other streams on the drift plain. Pumping from aquifers separated from the stream by one or more confining layers caused a reduction in the effects of pumping on discharge to
Oil and gas shows numerous in Nama basin, southern Africa
Walter, M.; Swart, R.; Summons, R.
1996-11-25
No local sources of oil and gas are on production in southwestern Africa. The as yet undeveloped Kudu gas field off Namibia is the first major discovery, but there are numerous shows in the onshore Nama basin that suggest there could be significant accumulations of hydrocarbons present. The Nama basin occupies 350,000 sq km of southern Namibia, western Botswana, and northwestern South Africa and contains 10 km or more of Neoproterozoic and Cambrian sediment. National petroleum Corp. of Namibia recently embarked on an assessment of the prospectivity of the basin, and there the authors report some of the first results.
Static Analysis Numerical Algorithms
2016-04-01
and Honeywell Aerospace Advanced Technology to combine model-based development of complex avionics control software with static analysis of the...numerical algorithms, software verification, formal methods 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18. NUMBER OF PAGES...18 3.3.4. Tool Software Integration Architecture
NASA Astrophysics Data System (ADS)
Henderson, Michael
1997-08-01
The Numerical Analysis Objects project (NAO) is a project in the Mathematics Department of IBM's TJ Watson Research Center. While there are plenty of numerical tools available today, it is not an easy task to combine them into a custom application. NAO is directed at the dual problems of building applications from a set of tools, and creating those tools. There are several "reuse" projects, which focus on the problems of identifying and cataloging tools. NAO is directed at the specific context of scientific computing. Because the type of tools is restricted, problems such as tools with incompatible data structures for input and output, and dissimilar interfaces to tools which solve similar problems can be addressed. The approach we've taken is to define interfaces to those objects used in numerical analysis, such as geometries, functions and operators, and to start collecting (and building) a set of tools which use these interfaces. We have written a class library (a set of abstract classes and implementations) in C++ which demonstrates the approach. Besides the classes, the class library includes "stub" routines which allow the library to be used from C or Fortran, and an interface to a Visual Programming Language. The library has been used to build a simulator for petroleum reservoirs, using a set of tools for discretizing nonlinear differential equations that we have written, and includes "wrapped" versions of packages from the Netlib repository. Documentation can be found on the Web at "http://www.research.ibm.com/nao". I will describe the objects and their interfaces, and give examples ranging from mesh generation to solving differential equations.
Numerical representation of rainfall field in the Yarmouk River Basin
NASA Astrophysics Data System (ADS)
Shentsis, Isabella; Inbar, Nimrod; Magri, Fabien; Rosenthal, Eliyahu
2017-04-01
, geomorphologic and climatic division of the basin. Difference between regional curves is comparable with amplitude of rainfall variance within the regions. In general, rainfall increases with altitude and decreases from west to east (south-east). It should be emphasized that (i) Lake Kinneret Basin (2,490 sq. km) was earlier divided into seven "orographic regions" and (ii) the Lake Kinneret Basin and the Yarmouk River Basin are presented by the system of regional curves X = f (Z) as one whole rainfall field in the Upper Jordan River Basin, where the mean annual rain (X) increases with altitude (Z) and decreases from west to east and from north to south. In the Yarmouk Basin there is much less rainfall (344 mm) than in the Lake Kinneret Basin (749 mm), wherein mean annual rain (2,352 MCM versus 1,865 MCM) is shared between Syria, Jordan and Israel as 80%, 15% and 5%, respectively. The provided rainfall data allow more precise estimations of surface water balances and of recharge to the regional aquifers in the Upper Jordan River Basin. The derived rates serve as fundamental input data for numerical modeling of groundwater flow. This method can be applied to other areas at different temporal and spatial scales. The general applicability makes it a very useful tool in several hydrological problems connected with assessment, management and policy-making of water resources, as well as their changes due to climate and anthropogenic factors. Reference: I. Shentsis (1990). Mathematical models for long-term prediction of mountainous river runoff: methods, information and results, Hydrological Sciences Journal, 35:5, 487-500, DOI: 10.1080/02626669009492453
BASIN: Beowulf Analysis Symbolic INterface
NASA Astrophysics Data System (ADS)
Vesperini, Enrico; Goldberg, David M.; McMillan, Stephen L. W.; Dura, James; Jones, Douglas
2013-08-01
BASIN (Beowulf Analysis Symbolic INterface) is a flexible, integrated suite of tools for multiuser parallel data analysis and visualization that allows researchers to harness the power of Beowulf PC clusters and multi-processor machines without necessarily being experts in parallel programming. It also includes general tools for data distribution and parallel operations on distributed data for developing libraries for specific tasks.
NASA Astrophysics Data System (ADS)
Clark, Martyn; Kavetski, Dmitri
2010-05-01
Much of the research in the PUB initiative is focused on the analysis and interpretation of model results in well instrumented watersheds, in order to inform appropriate model structures and parameter values for use in ungauged basins. However, many of the models used in PUB share a common characteristic: poor numerical implementation. It is likely that many published conclusions, including (i) parameter sensitivity, optima and uncertainty estimates, and, more disconcertingly, (ii) the interpretation of hydrologic model output to gain insights into internal catchment dynamics, including the relative significance and behavior of different processes, may be questionable due to numerical artifacts introduced by unreliable time stepping schemes. Such lack of attention to numerical schemes has almost certainly hindered progress in the PUB initiative. Here, we comprehensively evaluate several classes of time stepping schemes in terms of numerical fidelity, computational efficiency, and impact on model sensitivity analysis, calibration and prediction. Extensive numerical experiments are carried out using 8 distinct time stepping algorithms and 6 different conceptual hydrological models, applied in the densely gauged experimental Mahurangi catchment as well as in 12 MOPEX basins with diverse physical characteristics and hydroclimatic regimes. Results show that numerical errors of uncontrolled time stepping schemes, which remain widely used in hydrology, routinely dwarf the structural errors of the model conceptualization. This has serious implications for model analysis and predictive use, including inconsistent inferences of parameters and internal states even if the calibrated streamflow predictions are similar. Even when numerical errors allow "getting the right result for the wrong reason", they make the model unduly fragile in predictive mode, as evidenced in validation tests. The extensive analyses in this paper indicate that these deformations are not rare isolated
NASA Astrophysics Data System (ADS)
Li, Lu; Qiu, Nansheng; Xu, Wei
2016-04-01
Jiyang sub-basin is an oil-rich depression located in the southeast of Bohai Bay Basin, which is one of the most important hydrocarbon area in east of China. The thermal-rheological structure of the lithosphere can explain the dynamics evolution processes of basins, continental margins and orogenic belts, which directly reflects the characteristics of the lithosphere geodynamics. Nevertheless it is poorly to understand the evolution of lithospheric thermal-rheological structure in Jiyang sub-basin and its implication for basin extension. In this study, two dimensional numerical modelling is applied to calculate the paleo-temperature field and the thermo-lithospheric structure, which are used to estimate the evolution of lithospheric thermal-rheological structure. The results of study show that in Mesozoic the lithosphere was of relative rigidity and stable, as featured by large thickness and strength whereas after late Cretaceous the lithospheric strength decreased rapidly. The analysis of thermal-rheological properties shows that the lithospheric thermo-lithospheric structure is sandwiched-like with two ductile layers and two brittle layers. The upper crust is usually brittle. The brittle layers appear at outer 20km of the crust, below 20km ductile deformation predominates. There is also a 10km brittle layer on the top of the upper mantle. The integrated lithospheric yield strength is about 1.3-4.5×1012N/m, showing a weak lithosphere which may support the idea that the extension achieved by the ductile flow below the brittle layers. Keywords: lithospheric thermal-rheological structure; Jiyang sub-basin; Numerical modeling
Vertical Analysis of Martian Drainage Basins
NASA Technical Reports Server (NTRS)
Stepinski, T. F.; OHara, W. J.
2003-01-01
We have performed a vertical analysis of drainage basins on Mars that were computationally extracted from DEMs based on the MOLA data. Longitudinal profiles of main streams are calculated and the slope-area relation is established for 20 basins coming from assorted martian locations. An identical analysis is done for 19 terrestrial river basins. Our results show that, in comparison to terrestrial basins, martian basins have more linear longitudinal profiles, more frequent existence of knickpoints, predominance of asymmetric location of the main stream in the basin, and smaller values of concavity exponent. This suggests a limited role for surface runoff on the global scale. However, two basins extracted from the slopes of martian volcanoes show a strong similarity to terrestrial basins, indicating a possible local role for the process of surface runoff.
Numerical analysis of engine instability
NASA Astrophysics Data System (ADS)
Habiballah, M.; Dubois, I.
Following a literature review on numerical analyses of combustion instability, to give the state of the art in the area, the paper describes the ONERA methodology used to analyze the combustion instability in liquid propellant engines. Attention is also given to a model (named Phedre) which describes the unsteady turbulent two-phase reacting flow in a liquid rocket engine combustion chamber. The model formulation includes axial or radial propellant injection, baffles, and acoustic resonators modeling, and makes it possible to treat different engine types. A numerical analysis of a cryogenic engine stability is presented, and the results of the analysis are compared with results of tests of the Viking engine and the gas generator of the Vulcain engine, showing good qualitative agreement and some general trends between experiments and numerical analysis.
NASA Astrophysics Data System (ADS)
Moczo, P.; Kristek, J.; Galis, M.; Pazak, P.
2009-12-01
applicable to media with large Vp/Vs ratio and thus to real sedimentary basins. Surprisingly, FD_DS_PSG is the worst scheme for the lowest values of the Vp/Vs ratio. Errors of FD_DS_SG and FD_VS_SG are very close and small (relative to other schemes), and they are least sensitive to variation in Vp/Vs. In parallel with the numerical results and their analysis we compare the numerical schemes themselves in terms of their inherent structures and applied approximations. We also discuss properties of recent higher-order numerical schemes.
An Ensemble Numerical Modeling Study of Atlantic Basin Hurricane Intensification
NASA Astrophysics Data System (ADS)
Brown, Bonnie R.
Rapid intensification of tropical cyclones is an active area of research in the atmospheric sciences due to the difficulty of forecasting cyclone intensity and the unclear mechanism by which a hurricane my undergo explosive deepening. Ensemble numerical modeling studies of six tropical cyclones from 2009, 2010 and 2011 which underwent periods of strong intensification are conducted here. The goal is to identify common storm structures in intensifying hurricanes while filling a gap in the current research between case studies of rapid intensification and climatological/statistical type studies of hurricane intensification rates by using a compositing method. A 96-member ensemble is run for a 24 hour forecast using the Weather Research and Forecasting (WRF) model for hurricanes Bill (2009), Earl (2010), Igor (2010), Julia (2010), Katia (2011), and Ophelia (2011). Ensemble sensitivity analysis is used to investigate which patterns in the analysis have a strong influence on the forecast intensity and then a novel sensitivity compositing is used to identify common patterns which affect the forecast intensity. It is found that these hurricanes are all predicted to respond to an increased primary and secondary circulation, an increased warm core, a raised tropopause and moistening of rain bands with an increased forecast intensity. Perturbed initial conditions show a linear model response for small perturbations but also signs of non-linearity at large perturbations, indicating that these sensitivity patterns are robust for limited additional strengthening of the hurricane. When perturbations are partitioned into dry and moist variables, it is seen that most of the model response is achieved by the dry dynamics. Further investigation is conducted into the rapid intensification of Earl (2010) and Igor (2010) but creating ensemble forecasts with additional, high-resolution nested domains which allow explicit convection. When the ensemble sensitivity analysis is repeated
Numerical Simulation of Extent of Carbon Dioxide Plume Injected in the Gyeongsang Basin, Korea
NASA Astrophysics Data System (ADS)
Kihm, J.; Park, S.; Kim, J.
2012-12-01
A series of thermo-hydro-chemical numerical simulations was performed to evaluate extent of carbon dioxide plume injected in the Gyeongsang Basin, which is one of the prospective onshore sedimentary basins for geologic storage of carbon dioxide in Korea. The carbon dioxide plume extent is an important factor in estimating storage efficiency and thus storage capacity of carbon dioxide in a storage formation because it represents an actual volume of the storage formation, which is occupied by injected carbon dioxide. The carbon dioxide plume extent is also an essential component in risk analysis of geologic storage of carbon dioxide because most of thermo-hydro-mechanical-chemical responses to carbon dioxide injection occur within it. To evaluate impacts of injection scenarios (i.e., injection rate and period) of carbon dioxide and geological conditions (i.e., thickness and depth) and hydrogeochemical properties (i.e., porosity, intrinsic permeability, salt concentration in groundwater, and volume fraction of chlorite) of a storage formation on the carbon dioxide plume extent, a series of sensitivity tests was also performed. The numerical simulation results show that the carbon dioxide plume extent is significantly affected by such injection scenarios, geological conditions, and hydrogeochemical properties. The carbon dioxide plume extent increases as the injection rate (with a constant injection period) increases, and this trend does not change with time. The carbon dioxide plume extent decreases as the injection period (with a constant total injection amount) increases until about 50 years, while it is not sensitive to the injection period after about 50 years. The carbon dioxide plume extent also decreases as the thickness increases until about 100 years, while it is not sensitive to the thickness after about 100 years. In contrast, the carbon dioxide plume extent decreases as the depth increases, and this trend is intensified with time. On the other hand, the
BasinVis 1.0: A MATLAB®-based program for sedimentary basin subsidence analysis and visualization
NASA Astrophysics Data System (ADS)
Lee, Eun Young; Novotny, Johannes; Wagreich, Michael
2016-06-01
Stratigraphic and structural mapping is important to understand the internal structure of sedimentary basins. Subsidence analysis provides significant insights for basin evolution. We designed a new software package to process and visualize stratigraphic setting and subsidence evolution of sedimentary basins from well data. BasinVis 1.0 is implemented in MATLAB®, a multi-paradigm numerical computing environment, and employs two numerical methods: interpolation and subsidence analysis. Five different interpolation methods (linear, natural, cubic spline, Kriging, and thin-plate spline) are provided in this program for surface modeling. The subsidence analysis consists of decompaction and backstripping techniques. BasinVis 1.0 incorporates five main processing steps; (1) setup (study area and stratigraphic units), (2) loading well data, (3) stratigraphic setting visualization, (4) subsidence parameter input, and (5) subsidence analysis and visualization. For in-depth analysis, our software provides cross-section and dip-slip fault backstripping tools. The graphical user interface guides users through the workflow and provides tools to analyze and export the results. Interpolation and subsidence results are cached to minimize redundant computations and improve the interactivity of the program. All 2D and 3D visualizations are created by using MATLAB plotting functions, which enables users to fine-tune the results using the full range of available plot options in MATLAB. We demonstrate all functions in a case study of Miocene sediment in the central Vienna Basin.
Using PASCAL for numerical analysis
NASA Technical Reports Server (NTRS)
Volper, D.; Miller, T. C.
1978-01-01
The data structures and control structures of PASCAL enhance the coding ability of the programmer. Proposed extensions to the language further increase its usefulness in writing numeric programs and support packages for numeric programs.
Using PASCAL for numerical analysis
NASA Technical Reports Server (NTRS)
Volper, D.; Miller, T. C.
1978-01-01
The data structures and control structures of PASCAL enhance the coding ability of the programmer. Proposed extensions to the language further increase its usefulness in writing numeric programs and support packages for numeric programs.
Numerical Relativity meets Data Analysis
NASA Astrophysics Data System (ADS)
Schmidt, Patricia
2016-03-01
Gravitational waveforms (GW) from coalescing black hole binaries obtained by Numerical Relativity (NR) play a crucial role in the construction and validation of waveform models used as templates in GW matched filter searches and parameter estimation. In previous efforts, notably the NINJA and NINJA-2 collaborations, NR groups and data analysts worked closely together to use NR waveforms as mock GW signals to test the search and parameter estimation pipelines employed by LIGO. Recently, however, NR groups have been able to simulate hundreds of different binary black holes systems. It is desirable to directly use these waveforms in GW data analysis, for example to assess systematic errors in waveform models, to test general relativity or to appraise the limitations of aligned-spin searches among many other applications. In this talk, I will introduce recent developments that aim to fully integrate NR waveforms into the data analysis pipelines through a standardized interface. I will highlight a number of select applications for this new infrastructure.
The DESIRE Airborne gravity project in the Dead Sea Basin and 3D numerical gravity modeling
NASA Astrophysics Data System (ADS)
Choi, Sungchan; Götze, Hans-Jürgen; Meyer, Uwe; Desire-Group
2010-05-01
This geo-scientific research focuses on the geological setting of the Dead Sea Transform (DST) and the Dead Sea Basin (DSB) and its resulting pull-apart basins. Since the late 1970s, crustal scale geophysical experiments have been carried out in this region. However, the nature of the crust underlying the eastern and western shoulders of the DSB and underneath the DST itself is still a hotly debated topic among researchers. To address one of the central questions of plate tectonics - How do large transform systems work and what are their typical features? - An international geoscientific Dead Sea Integrated Research project (DESIRE) is being conducted by colleagues from Germany, Israel, Palestine, and Jordan. In order to provide a high resolution gravity database that support 3D numerical modeling and hence a more comprehensive understanding of the nature and segmentation of the DST, an airborne gravity survey as a part of the DESIRE project has been carried out from February to March 2007. The airborne gravity survey covered the DST from Elat/Aqaba in the South to the northern rim of the Dead Sea. The low speed and terrain-following helicopter gravity flights were performed to acquire the highest possible data quality. In total, 32 north-south profiles and 16 west-east profiles crossing the DST have been measured. Most of the profiles concentrated in areas that lacked terrestrial gravity data coverage, e. g. over the shoulders of the DSB. The airborne gravity data are merged with existing conventional (terrestrial) data sets to provide a seamless gravity map of the area of interest. The results of the 3D gravity modelling based the GPS analysis, magnetic field characters, seismic researches and analysis of earthquake data allow us to propose that (1) the DSB is divided into two tectonic blocks by the region between the Lisan peninsula and the southern margin of the northern DSB and (2) the tectonic system in the DSB is defined as a counter-clockwise rotating pull
NASA Astrophysics Data System (ADS)
Caldeira, R. M. A.; Couvelard, X.; Casella, E.; Vetrano, A.
2012-11-01
A high-resolution ocean circulation modelling system forced with a high-resolution numerical wind product was used to study the mesoscale and sub-mesoscale eddy population of the North-Western Mediterranean Sea, contrasting eddy-activity between the Tyrrhenian and Ligurian sub-basins. Numerical solutions reproduced some of the known regional dynamics, namely the occurrence and oceanic implications of Mistral events, the convective cell leeward of the Gulf of Lion, as well as the Balearic frontal system. Calculated transport across the Corsica Channel followed a similar trend, when compared to the transport computed from a moored current meter. The analysis of the results showed that surface eddy activity is mostly confined to the boundary-currents, whereas in the deeper layers most eddies are concentrated on the central-deeper part of the basins. The Liguro-Provençal basin shows a much higher concentration of intermediate and deep-water eddies, when compared to the Tyrrhenian basin. Sub-mesoscale surface eddies tend to merge and migrate vertically onto intermediate waters. Intense eddy activity in the boundary-current surrounding the Liguro-Provençal Gyre, concentrate high-productivity, manifested by higher concentrations of mean sea surface chlorophyll, in the central part of the gyre, defined herein as the Ligurian Productive Pool (LPP). On average, the Tyrrhenian was mostly oligotrophic except for a small productive vortice in the south-eastern (leeward) side of Corsica. The transport in the Tyrrhenian Gyre, and across the basin is one order of magnitude higher than the transport calculated for the Liguro-Provençal basin. A high concentration of eddies in the passage between the Balearic Archipelago and Sardinia suggests retention and longer residence times of nutrient rich water in the "Ligurian pool", compared to a "fast draining" Tyrrhenian basin. Previous studies support the cyclonic gyre circulation generated in the Liguro-Provençal basin but more
Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) is a multipurpose environmental analysis system designed to help regional, state, and local agencies perform watershed- and water quality-based studies.
Numerical Package in Computer Supported Numeric Analysis Teaching
ERIC Educational Resources Information Center
Tezer, Murat
2007-01-01
At universities in the faculties of Engineering, Sciences, Business and Economics together with higher education in Computing, it is stated that because of the difficulty, calculators and computers can be used in Numerical Analysis (NA). In this study, the learning computer supported NA will be discussed together with important usage of the…
Flemings, P.B.; Jordan, T.E.; Reynolds, S.
1986-05-01
Lithospheric flexure that generates basin in a broke foreland setting (e.g., the Laramide foreland of Wyoming) is a three-dimensional system related to shortening along basin-bounding faults. The authors modeled the elastic flexure in three dimensions for two broken foreland basins: the early Cenozoic Green River basin and the analogous late Cenozoic Bermejo basin of Argentina. Each basin is located between a thrust belt and a reverse-fault-bounded basement uplift. Both basins are asymmetric toward the basement uplifts and have a central basement high: the Rock Springs uplift and the Pie de Palo uplift, respectively. The model applies loads generated by crustal thickening to an elastic lithosphere overlying a fluid mantle. Using the loading conditions of the Bermejo basin based on topography, limited drilling, and reflection and earthquake seismology, the model predicts the current Bermejo basin geometry. Similarly, flexure under the loading conditions in the Green River basin, which are constrained by stratigraphy, well logs, and seismic profiling and summed for Late Cretaceous (Lance Formation) through Eocene (Wasatch Formation), successfully models the observed geometry of the pre-Lance surface. Basin depocenters (> 4 km for the Green River basin; > 7 km for the Bermejo basin) and central uplifts are predicted to result from constructive interference of the nonparallel applied loads. Their Bermejo model implies that instantaneous basin geometry is successfully modeled by crustal loading, whereas the Green River basin analysis suggests that basin evolution can be modeled over large time steps (e.g., 20 Ma). This result links instantaneous basin geometry to overall basin evolution and is a first step in predicting stratigraphic development.
NASA Astrophysics Data System (ADS)
Rybarski, S.; Pohll, G.; Pohlmann, K.; Plume, R.
2014-12-01
In recent years, hydraulic fracturing (fracking) has become an increasingly popular method for extraction of oil and natural gas from tight formations. Concerns have been raised over a number of environmental risks associated with fracking, including contamination of groundwater by fracking fluids, upwelling of deep subsurface brines, and methane migration. Given the potentially long time scale for contaminant transport associated with hydraulic fracturing, numerical modeling remains the best practice for risk assessment. Oil shale in the Humboldt basin of northeastern Nevada has now become a target for hydraulic fracturing operations. Analysis of regional and shallow groundwater flow is used to assess several potential migration pathways specific to the geology and hydrogeology of this basin. The model domain in all simulations is defined by the geologic structure of the basin as determined by deep oil and gas well bores and formation outcrops. Vertical transport of gaseous methane along a density gradient is simulated in TOUGH2, while fluid transport along faults and/or hydraulic fractures and lateral flow through more permeable units adjacent to the targeted shale are modeled in FEFLOW. Sensitivity analysis considers basin, fault, and hydraulic fracturing parameters, and results highlight key processes that control fracking fluid and methane migration and time scales under which it might occur.
Khangaonkar, Tarang; Yang, Zhaoqing; Kim, Tae Yun; Roberts, Mindy
2011-07-20
Through extensive field data collection and analysis efforts conducted since the 1950s, researchers have established an understanding of the characteristic features of circulation in Puget Sound. The pattern ranges from the classic fjordal behavior in some basins, with shallow brackish outflow and compensating inflow immediately below, to the typical two-layer flow observed in many partially mixed estuaries with saline inflow at depth. An attempt at reproducing this behavior by fitting an analytical formulation to past data is presented, followed by the application of a three-dimensional circulation and transport numerical model. The analytical treatment helped identify key physical processes and parameters, but quickly reconfirmed that response is complex and would require site-specific parameterization to include effects of sills and interconnected basins. The numerical model of Puget Sound, developed using unstructured-grid finite volume method, allowed resolution of the sub-basin geometric features, including presence of major islands, and site-specific strong advective vertical mixing created by bathymetry and multiple sills. The model was calibrated using available recent short-term oceanographic time series data sets from different parts of the Puget Sound basin. The results are compared against (1) recent velocity and salinity data collected in Puget Sound from 2006 and (2) a composite data set from previously analyzed historical records, mostly from the 1970s. The results highlight the ability of the model to reproduce velocity and salinity profile characteristics, their variations among Puget Sound subbasins, and tidally averaged circulation. Sensitivity of residual circulation to variations in freshwater inflow and resulting salinity gradient in fjordal sub-basins of Puget Sound is examined.
SE Great Basin Play Fairway Analysis
Adam Brandt
2015-11-15
Within this submission are multiple .tif images with accompanying metadata of magnetotelluric conductor occurrence, fault critical stress composite risk segment (CRS), permeability CRS, Quaternary mafic extrusions, Quaternary fault density, and Quaternary rhyolite maps. Each of these contributed to a final play fairway analysis (PFA) for the SE Great Basin study area.
NASA Astrophysics Data System (ADS)
Chernov, Anton; Kurkin, Andrey; Pelinovsky, Efim; Yalciner, Ahmet; Zaytsev, Andrey
2010-05-01
A short cut numerical method for evaluation of the modes of free oscillations of the basins which have irregular geometry and bathymetry was presented in the paper (Yalciner A.C., Pelinovsky E., 2007). In the method, a single wave is inputted to the basin as an initial impulse. The respective agitation in the basin is computed by using the numerical method solving the nonlinear form of long wave equations. The time histories of water surface fluctuations at different locations due to propagation of the waves in relation to the initial impulse are stored and analyzed by the fast Fourier transform technique (FFT) and energy spectrum curves for each location are obtained. The frequencies of each mode of free oscillations are determined from the peaks of the spectrum curves. Some main features were added for this method and will be discussed here: 1. Instead of small number of gauges which were manually installed in the studied area the information from numerical simulation now is recorded on the regular net of the «simulation» gauges which was place everywhere on the sea surface in the depth deeper than "coast" level with the fixed presetted distance between gauges. The spectral analysis of wave records was produced by Welch periodorgam method instead of simple FFT so it's possible to get spectral power estimation for wave process and determine confidence interval for spectra peaks. 2. After the power spectral estimation procedure the common peak of studied seiche can be found and mean spectral amplitudes for this peak were calculated numerically by a Simpson integration method for all gauges in the basin and the mean spectral amplitudes spatial distribution map can be ploted. The spatial distribution helps to study structure of seiche and determine effected dangerous areas. 3. Nested grid module in the NAMI-DANCE - nonlinear shallow water equations calculation software package was developed. This is very important feature for complicated different scale (ocean
Numerical Simulation of Petroleum Generation and Migration in the Song Hong Basin, Vietnam
NASA Astrophysics Data System (ADS)
Son, Byeong-Kook; Thi Nguyen, Hong; Park, Mee-Sook
2014-05-01
The numerical modeling of petroleum systems is an effective tool to understand generation, migration and accumulation of hydrocarbons in a sedimentary basin and hence to determine future targets for the hydrocarbon exploration. The numerical modeling identifies two petroleum systems in the Song Hong Basin, which is a petroliferous Cenozoic basin, offshore eastern Vietnam. These petroleum systems were named DinhCao-PhuCu(.) Petroleum System and SongHuong-BienDong(.) Petroleum System. DinhCao-PhuCu(.) Petroleum System covers northern and central parts of the Song Hong basin with Oligocene shale and coaly shale source rocks of Dinh Cao formation, which are dominated by type II-III kerogens. The hydrocarbon generation starts at 13 Ma within deeply buried Oligocene strata located in the centre of the basin. The hydrocarbon expels from the Oligocene source rock and migrates laterally and then up dip toward marginal areas where Middle Miocene sandstones of Phu Cu formation are present as major reservoirs. The numerical model shows that the critical moment occurs at about 3.5 Ma. The DinhCao-PhuCu(.) petroleum system is confirmed by sparse occurrence of oil and gas along the coast of eastern Vietnam. SongHuong-BienDong(.) Petroleum System is identified in limited areas of the central and southern Song Hong basin. The major source rock of this petroleum system is Lower Miocene dark claystones of Song Huong formation which contain gas prone, type III kerogen. The migration model shows that hydrocarbons are generated from the Miocene source rocks in the center of the basin at about 12 Ma, and migrates updip through sand bodies of Quang Ngai formation to the major boundaries faults, and further moves into highly permeable up-dipping units, the Bien Dong formation. The best depiction of the generation-migration-accumulation of hydrocarbons occurs at about 2 Ma. The presence of the SongHuong-BienDong(.) Petroleum System is indicated by the large gas fields in the central and
Mesoscale Circulations in the LOS Angeles Basin: a Numerical Modeling Study
NASA Astrophysics Data System (ADS)
Ulrickson, Brian Lee
1988-08-01
Mesoscale atmospheric forcing in the Los Angeles Basin was investigated by means of a numerical model and observations. Special attention was paid to airflows that are important to the transport of pollutants in the region. The numerical model was modified in order to improve its numerical stability and enhance its accuracy in the context of sharp topographic relief and strong sea/land thermal contrasts. Output from two simulations were compared with observations to document the model's strengths and weaknesses. Overall, the model results compared well with the observations. Large-scale conditions typical of summer and winter smog episodes were discovered by compositing cases described in the literature. Summer and winter simulations were performed, with and without the large-scale winds typical of the summer and winter episodes, and the results were analyzed. Light geostrophic winds were found to have little influence on the strong mesoscale circulations predicted for the summer day, but stronger geostrophic winds exerted considerable influence on the weaker mesoscale circulations that occurred on the winter day. Standard model predictions and computations of air-parcel trajectories indicate that daytime upslope flows near the mountains are a significant factor in the ventilation of the basin, inducing basin -wide airflow that modifies the sea breeze circulation, whose influence is limited to the coastal parts of the basin. Heating of the mountain slopes also induces a weak onshore flow in the inversion layer and above. Air that is transported from the basin's shallow boundary layer to the ridgetops is predicted to rise in updrafts there and be convectively mixed to great heights, where it is then transported horizontally by winds aloft. Boundary layer air is also predicted to leave the basin through three mountains passes, be convectively mixed through a much deeper boundary layer in the desert, and travel back into the basin above the inversion base. Air that is
NASA Astrophysics Data System (ADS)
Lin, S.; Chung, S.; Kuo, B.
2009-12-01
Backarc basin basalts can be characterized as fertile, MORB-like end-member mixed with water-rich, previously depleted, arc-like components in various proportions. In addition, an enriched component might also contribute to the magma generation. A number of melting processes have been proposed to account for the chemical systematics of the backarc basin basalts. Previous numerical model experiments for circulation and thermal evolution in the subduction zones generally consider a steady spreading center, corresponding to mature stages. In this study we attempt to better understand the roles of different melting mechanisms and magma sources using a series of thermomechemical models of evolution of backarc basins. In the models the effects of rifting-spreading transition, ridge migration and asymmetric spreading on the thermal field, fluid distribution and melting history are incorporated. We focused on the evolution of the Mariana subduction system because the Mariana subduction zone is one of the best sampled region and its tectonic environment and history are relatively simple. Furthermore, the variations along the strike of the Mariana trough represent the sequence of the evolution of a backarc basin from rifting to mature stages of spreading. The effects of modeling parameters including slab geometry, spreading rate, velocity of subducting slab, lithospheric rheology and crustal thickness have been investigated. How the melting regimes and magma sources may evolve with time in the Mariana arc-basin system will be presented.
Numerical Analysis in Fracture Mechanics.
1983-01-20
in the following. A. 2-D Elastic-Plastic Crack Problem In 1975, ASTh Committee E24.01.09 undertook a task to compare numerical solutions to elastic...Penalty Function and Superposition Method", Fracture Mechanics, 12th Symposium, ed. by P. C. Paris, ASTh SIP 700, p. 439, 1980. [44) Barsoum, R...Landes, J. A. Begley and G. A. Clarke, ASTh SIP 668, p. 65, 1979. [46) Benzley, S., "Nonlinear Calculations With a Quadratic Quarter-point Crack Tip
Precambrian shield and basement tectonics in sedimentary basin analysis
Touborg, J.F.
1984-04-01
This study focused on the use of (1) regional structural analysis of basement and Precambrian rocks surrounding a sedimentary basin, and (2) tracing basement structures into the sedimentary basin. The structural analysis of the Precambrian shield has a fundamental bearing on interpretation of overlying sedimentary cover rocks. This is expressed in the southern part of the Hudson's Bay basin and its southeastern arm, the Moose River basin. For instance, the rims of both basins are controlled by faults or graben structures. Approximately 13 major fault systems with strike lengths of 200-300 km (125-186 mi) or more can be traced from the exposed Precambrian shield into the basin in terms of lineament arrays and/or aeromagnetic and/or gravity signature. The data suggest reactivation of faults during basin sedimentation. This type of basement structural analysis in areas adjacent to sedimentary basins can provide a valuable interpretation base for subsequent seismic surveys and basin evaluation.
NASA Astrophysics Data System (ADS)
Girou, O.; Lemieux, J. M.; Malo, M.
2015-12-01
Full-scale carbon capture and storage in deep saline aquifers implies injecting important quantities of carbon in order to significantly reduce greenhouse gases emissions. At the basin scale, impacts related to CO2 injection are pressure perturbation as well as brine migration into freshwater aquifers. In this study, potential impacts of an industrial-scale carbon capture and storage project in Bécancour (Quebec, Canada), in the St. Lawrence Lowlands basin, are discussed, as well as the role played by regional normal faults that divide the basin into multiple compartments. The basin is 300 km long and 90 km wide, formed by sub-horizontal Paleozoic formations on top of which the Utica and Lorraine shale formations represent the caprock of the potential CO2reservoir. These formations cover most of the basin, except in its eroded northwestern part, located between 10 to 40 km away from the potential injection sites. Three injection scenarios were considered, corresponding to greenhouse gases emissions from large emitters located; in Bécancour industrial park, in a larger area that allow affordable transport and in the entire basin without considering transport costs (1, 5, 10 Mt/yr). The numerical model FEFLOW was used to simulate CO2 injection into different compartments to evaluate pressure build up propagation and brine migration in order to define which compartments are best suited for long-term storage. The simulations considered an injection period of 100 years and post-injections period of 1000 years. Numerical simulations indicate that normal faults, which exhibit a low hydraulic conductivity, play a major role orienting pressure build-up and brine migration. Due to the presence of normal faults, no pressure build up occurred close to the surface. Similarly, preliminary mass transport simulations show very limited brine migration. These first results indicate that basin-scale impacts of carbon injection are low for the 3 injection scenarios, however, the
Tularosa Basin Play Fairway Analysis: Strain Analysis
Adam Brandt
2015-11-15
A DEM of the Tularosa Basin was divided into twelve zones, each of which a ZR ratio was calculated for. This submission has a TIFF image of the zoning designations, along with a table with respective ZR ratio calculations in the metadata.
Analysis of K west basin canister gas
Trimble, D.J., Fluor Daniel Hanford
1997-03-06
Gas and Liquid samples have been collected from a selection of the approximately 3,820 spent fuel storage canisters in the K West Basin. The samples were taken to characterize the contents of the gas and water in the canisters providing source term information for two subprojects of the Spent Nuclear Fuel Project (SNFP) (Fulton 1994): the K Basins Integrated Water Treatment System Subproject (Ball 1996) and the K Basins Fuel Retrieval System Subproject (Waymire 1996). The barrels of ten canisters were sampled for gas and liquid in 1995, and 50 canisters were sampled in a second campaign in 1996. The analysis results from the first campaign have been reported (Trimble 1995a, 1995b, 1996a, 1996b). The analysis results from the second campaign liquid samples have been documented (Trimble and Welsh 1997; Trimble 1997). This report documents the results for the gas samples from the second campaign and evaluates all gas data in terms of expected releases when opening the canisters for SNFP activities. The fuel storage canisters consist of two closed and sealed barrels, each with a gas trap. The barrels are attached at a trunion to make a canister, but are otherwise independent (Figure 1). Each barrel contains up to seven N Reactor fuel element assemblies. A gas space of nitrogen was established in the top 2.2 to 2.5 inches (5.6 to 6.4 cm) of each barrel. Many of the fuel elements were damaged allowing the metallic uranium fuel to be corroded by the canister water. The corrosion releases fission products and generates hydrogen gas. The released gas mixes with the gas-space gas and excess gas passes through the gas trap into the basin water. The canister design does not allow canister water to be exchanged with basin water.
SE Great Basin Play Fairway Analysis
Adam Brandt
2015-11-15
This submission includes a Na/K geothermometer probability greater than 200 deg C map, as well as two play fairway analysis (PFA) models. The probability map acts as a composite risk segment for the PFA models. The PFA models differ in their application of magnetotelluric conductors as composite risk segments. These PFA models map out the geothermal potential in the region of SE Great Basin, Utah.
Numerical assessment of ASR recharge using small-diameter wells and surface basins
NASA Astrophysics Data System (ADS)
Händel, Falk; Liu, Gaisheng; Dietrich, Peter; Liedl, Rudolf; Butler, James J.
2014-09-01
Aquifer storage and recovery (ASR) methods are increasingly used to overcome the temporal imbalance between water demand and availability. Common ASR recharge methods utilize large-diameter injection wells or surface infiltration basins and trenches, and can be costly to implement. A new low-cost ASR recharge method is currently being developed. This approach is based on recharge via gravity in small-diameter wells installed with direct-push (DP) technology. Numerical modeling is used here to assess the potential of this new approach under conditions commonly faced in field settings. The primary objective is to investigate if a battery of small-diameter DP wells can serve as a viable alternative to a surface basin under typical field conditions, while the secondary objective is to assess which subsurface parameters have the greatest control on DP well performance. Simulation results indicate that gravity recharge via small-diameter wells appears to have a distinct advantage over recharge via surface infiltration basins. For example, two 0.05-m shallow vadose-zone wells with 9-m screens can recharge water at a greater rate than a 60 m2 basin. Also, results reveal that, contrary to an infiltration basin, the recharge rate in a DP well has a much stronger dependence on the horizontal component of hydraulic conductivity than on the vertical component. Moreover, near-surface layers of low hydraulic conductivity, which can significantly reduce the recharge capacity of a surface basin, have a relatively small impact on the recharge capacity of a well as long as a significant portion of the well screen is installed below those layers. Given that installation and operation costs can be low in comparison to common ASR recharge methods, this new approach appears to have great potential for recharging good quality water in shallow unconsolidated aquifers. A field investigation has recently been initiated to follow up the findings of this simulation assessment.
The application of environmental numerical simulation in pollutants migration into river basin
NASA Astrophysics Data System (ADS)
Liang, Z. R.; Qin, Y. J.; Zhou, J. G.; Nan, H. Y.
2017-01-01
For the sustainable development of the social economy, it is very important that the water environment quality is analyzed, evaluated and predicted rationally, so that it could be planned, harnessed and managed effectively. To analyze and predict the water environment, the hydrodynamics behaviors and water pollution situations of the water body must be analyzed first based on hydrodynamics and water quality models. The objective of this work is to introduce how to establish river water dynamics and water quality model through the environment in the basin pollutant migration transformation rule, to simulate the rules and dynamics of river water pollution situation, to introduce the water quality model with geographic information system (GIS), and to apply the combination of environment numerical simulation to basin pollutant migration problem.
A.B. Gilliam; R.W.H. Carroll; G. Pohll; R.L. Hershey
2006-01-01
A detailed, transient, three-dimensional, finite-difference groundwater flow model was created for the Mercury Valley Administrative Groundwater Basin (MVB). The MVB is a distinct groundwater basin as defined by the State of Nevada and is located partially within the boundary of the Nevada Test Site. This basin is being studied as a potential location for new industrial facilities and therefore would be subject to Nevada water-use limitations. The MVB model was used to estimate the volume of water that could be withdrawn from Mercury Valley without inducing laterally or vertically extensive water-table effects. In each model simulation, water-table drawdown was limited to a maximum of 0.5 m at the boundary of the basin and held within the screened interval of the well. Water withdrawal from Nevada groundwater basins is also limited to the State-defined perennial yield for that area. The perennial yield for the MVB is 27,036 m{sup 3}/day. The one existing water-supply well in Mercury Valley is capable of sustaining significantly higher withdrawal rates than it currently produces. Simulations showed this single well could produce 50 percent of the basin?s perennial yield with limited water-table drawdown. Pumping from six hypothetical water-supply wells was also simulated. Each hypothetical well was placed in an area of high hydraulic conductivity and far from the basin's boundaries. Each of these wells was capable of producing at least 50 percent of the basin's perennial yield. One of the hypothetical wells could simulate 100 percent of the perennial yield while staying within drawdown limitations. Multi-well simulations where two or more water-supply wells were simultaneously pumping were also conducted. These simulations almost always resulted in very limited lateral and vertical drawdown and produced 100 percent of Mercury Valley's perennial yield. A water-budget analysis was also conducted for each of the various stress simulations. Each of the stress scenarios
Simple numerical analysis of longboard speedometer data
NASA Astrophysics Data System (ADS)
Hare, Jonathan
2013-11-01
Simple numerical data analysis is described, using a standard spreadsheet program, to determine distance, velocity (speed) and acceleration from voltage data generated by a skateboard/longboard speedometer (Hare 2012 Phys. Educ. 47 409-17). This simple analysis is an introduction to data processing including scaling data as well as simple numerical differentiation and integration. This is an interesting, fun and instructive way to start to explore data manipulation at GCSE and A-level—analysis and skills so essential for the engineer and scientist.
Simple Numerical Analysis of Longboard Speedometer Data
ERIC Educational Resources Information Center
Hare, Jonathan
2013-01-01
Simple numerical data analysis is described, using a standard spreadsheet program, to determine distance, velocity (speed) and acceleration from voltage data generated by a skateboard/longboard speedometer (Hare 2012 "Phys. Educ." 47 409-17). This simple analysis is an introduction to data processing including scaling data as well as…
Simple Numerical Analysis of Longboard Speedometer Data
ERIC Educational Resources Information Center
Hare, Jonathan
2013-01-01
Simple numerical data analysis is described, using a standard spreadsheet program, to determine distance, velocity (speed) and acceleration from voltage data generated by a skateboard/longboard speedometer (Hare 2012 "Phys. Educ." 47 409-17). This simple analysis is an introduction to data processing including scaling data as well as…
Morphometric analysis of Suketi river basin, Himachal Himalaya, India
NASA Astrophysics Data System (ADS)
Pophare, Anil M.; Balpande, Umesh S.
2014-10-01
Suketi river basin is located in the Mandi district of Himachal Pradesh, India. It encompasses a central inter-montane valley and surrounding mountainous terrain in the Lower Himachal Himalaya. Morphometric analysis of the Suketi river basin was carried out to study its drainage characteristics and overall groundwater resource potential. The entire Suketi river basin has been divided into five sub-basins based on the catchment areas of Suketi trunk stream and its major tributaries. Quantitative assessment of each sub-basin was carried out for its linear, areal, and relief aspects. The analysis reveals that the drainage network of the entire Suketi river basin constitutes a 7th order basin. Out of five sub-basins, Kansa khad sub-basin (KKSB), Gangli khad sub-basin (GKSB) and Ratti khad sub-basin (RKSB) are 5th order sub-basins. The Dadour khad sub-basin (DKSB) is 6th order sub-basin, while Suketi trunk stream sub-basin (STSSB) is a 7th order sub-basin. The entire drainage basin area reflects late youth to early mature stage of development of the fluvial geomorphic cycle, which is dominated by rain and snow fed lower order streams. It has low stream frequency (Fs) and moderate drainage density (Dd) of 2.69 km/km 2. Bifurcation ratios (Rb) of various stream orders indicate that streams up to 3rd order are surging through highly dissected mountainous terrain, which facilitates high overland flow and less recharge into the sub-surface resulting in low groundwater potential in the zones of 1st, 2nd, and 3rd order streams of the Suketi river basin. The circulatory ratio (Rc) of 0.65 and elongation ratio (Re) of 0.80 show elongated nature of the Suketi river basin, while infiltration number (If) of 10.66 indicates dominance of relief features and low groundwater potential in the high altitude mountainous terrain. The asymmetry factor (Af) of Suketi river basin indicates that the palaeo-tectonic tilting, at drainage basin scale, was towards the downstream right side of the
Numerical simulation of groundwater flow in the Peshawar intermontane basin, northwest Himalayas
NASA Astrophysics Data System (ADS)
Yousafzai, Asim; Eckstein, Yoram; Dahl, Peter
2008-11-01
The hypothesis that abnormal fluid pressure is generated in basins under tectonic compression is tested. The study site, between the Main Karakoram Thrust (MKT), Main Mantle Thrust (MMT), Main Central Thrust (MCT), Main Boundary Thrust (MBT) and Salt Range Thrust (SRT) in northwest Pakistan, is experiencing a tectonic compression of 90 MPa. The Peshawar basin is a broad, oval depression comprising a thick sequence of lacustrine, deltaic and fluvial sediments overlain by loess and alluvial deposits dated at 2.8-0.6 Ma. It is surrounded by the Precambrian and Tertiary intrusive and metamorphic rocks on the north and sedimentary rocks of Paleogene and Neogene to the south. The basin was divided into four hydrostratigraphic units for numerical simulations using the three-dimensional finite-element model FEMWATER within groundwater modeling system (GMS) ver. 5.1. Simulated pressure head data have been compared with the field measurements of hydraulic heads. Transient simulations indicate that topography alone is not sufficient to induce the pressure heads observed in the field, generating consistently positive residuals 0.98-2.90 m over the topography-driven flow. The residuals disappeared after inclusion of the elastic properties of the four hydrostratigraphic units in the model, suggesting the effect of tectonic compression.
A numerical approach to thermal history modelling in an extensional basin
NASA Astrophysics Data System (ADS)
Tunwal, Mohit; Mulchrone, Kieran; Meere, Patrick
2017-04-01
Temperature plays an important role in many geological phenomena. In sedimentary basins, maturation of hydrocarbon source rocks depends on the temperature history after deposition. Sedimentation rate, geothermal gradient and duration of sedimentation are therefore key parameters controlling the thermal evolution. The McKenzie model is a widely accepted model for extensional basin formation which can be used for estimating post-rift subsidence, rate of sedimentation and basal heat flow. In this work, a numerical model in 1D has been implemented based on McKenzie's model and allows for the estimation of the thermal evolution of post-rift sediments and the rate of subsidence. The finite difference method is used to solve the heat equation in the sediments, crust and upper mantle. At each time step, subsidence due to thermal relaxation is calculated and added to the system. In this way the generalised moving boundary thermal diffusion problem is solved. Heat generated due to radioactivity may also be taken into account. The numerical model when compared to the McKenzie model gives significantly lower thermal subsidence estimates. Final thermal subsidence for the two models are compared with respect to the stretching factor. This model shows that significantly higher stretching is required to achieve the same level of thermal subsidence when compared to the McKenzie model. For example in the McKenzie model a 5 km of thermal subsidence is achieved with 280% stretching whereas this model requires 450% stretching.
5. Basin assessment and watershed analysis
Leslie M. Reid; Robert R. Ziemer
1994-01-01
Abstract - Basin assessment is an important component of the President's Forest Plan, yet it has received little attention. Basin assessments are intended both to guide watershed analyses by specifying types of issues and interactions that need to be understood, and, eventually, to integrate the results of watershed analyses occurring within a river basin....
NASA Astrophysics Data System (ADS)
Laviola, S.; Moscatello, A.; Miglietta, M. M.; Cattani, E.; Levizzani, V.
2012-04-01
The Mediterranean extreme rainfall events often develop at the end of the warm season when the sea surface temperature is higher than 15°C and the environmental conditions allow for the deepening of convection up to the formation of intense isolated cells and multicellular systems. Although the genesis of these phenomena are connected to the cold fronts in the westerlies with lifting of the oceanic systems operated by the Atlas mountains, the variation of a few local meteorological variables contributes to differentiate the developing stage of such systems. A study is proposed in which two heavy rain events over Mediterranean basin are analysed (Laviola et al., 2011). The investigation of cloud and precipitation properties are first assessed using a geostationary multifrequency satellite method for the identification of cloud type, hydrometeor phase, and cloud vertical extension. Then the study is carried out by means of a triple approach: (1) surface rain gauges, (2) satellite data, and (3) numerical model simulations. The satellite retrieval method 183-WSL (Laviola and Levizzani, 2009; 2011) is used to retrieve precipitation amount and classify precipitation type in terms of stratiform and convective rain. Furthermore, starting from two case studies, almost ten years of autumnal rain events over the Mediterranean are studied using a new method to identify the cloud type on the basis of the perturbation of the nominal signal in the microwave due to the presence of clouds. This technique exploits the properties of the three water vapour channels in the band at 183 GHz on board the NOAA-AMSU-B/MHS satellites. Due to the vertical development of the different cloud types, the typical extinction of radiation in clear sky conditions is perturbed as a function of cloud type and cloud top height. Stratified thin clouds, for example, usually impact less over the water vapour channels peaking at lower altitudes and often appear transparent or completely masked by the
NASA Astrophysics Data System (ADS)
Gramusset, Anneli; Herrera, Paulo; Parada, Miguel Angel
2014-05-01
A thorough understanding of the thermal processes that occur in aquifers is essential to assess local and regional low enthalpy geothermal resources. The relationship between heat convection and heat conduction has been widely studied in basins around the world at a regional scale. However, few studies have focused on smaller, shallower basins containing free aquifers hosted in unconsolidated fluvial-alluvial sediments, like Santiago Basin. We use numerical modeling to simulate the fluid dynamics of the Santiago basin groundwater system under different thermal conditions. Despite the current computational advances, modeling such a complex system with a full 3D approach is still numerically time demanding and unstable. Besides, the basin has irregular geometry and variable hydraulic and thermal features. Thus, we performed a 2D model comprising a thin water saturated slice of sediments beneath the central part of the city, where the basin morphology is well constrained. We simulate coupled groundwater and heat flow throughout this vertical slice and we compare results for different scenarios that comprise different hydraulic, thermal and geometric parameters. Results obtained with certain hydraulic conductivities show that instabilities appear giving rise to free thermal convection in the deepest parts of the basin. If the system is split into several hydrogeological units, the onset of these instabilities is inhibited. Consequently, we suggest that the stratigraphic complexities of a fluvial-alluvial deposit should be considered to better understanding the thermal-driven groundwater fluid dynamics.
Manufacturing in space: Fluid dynamics numerical analysis
NASA Technical Reports Server (NTRS)
Robertson, S. J.; Nicholson, L. A.; Spradley, L. W.
1981-01-01
Natural convection in a spherical container with cooling at the center was numerically simulated using the Lockheed-developed General Interpolants Method (GIM) numerical fluid dynamic computer program. The numerical analysis was simplified by assuming axisymmetric flow in the spherical container, with the symmetry axis being a sphere diagonal parallel to the gravity vector. This axisymmetric spherical geometry was intended as an idealization of the proposed Lal/Kroes growing experiments to be performed on board Spacelab. Results were obtained for a range of Rayleigh numbers from 25 to 10,000. For a temperature difference of 10 C from the cooling sting at the center to the container surface, and a gravitional loading of 0.000001 g a computed maximum fluid velocity of about 2.4 x 0.00001 cm/sec was reached after about 250 sec. The computed velocities were found to be approximately proportional to the Rayleigh number over the range of Rayleigh numbers investigated.
Ahmad, Zulfiqar; Ashraf, Arshad; Fryar, Alan; Akhter, Gulraiz
2011-02-01
The integration of the Geographic Information System (GIS) with groundwater modeling and satellite remote sensing capabilities has provided an efficient way of analyzing and monitoring groundwater behavior and its associated land conditions. A 3-dimensional finite element model (Feflow) has been used for regional groundwater flow modeling of Upper Chaj Doab in Indus Basin, Pakistan. The approach of using GIS techniques that partially fulfill the data requirements and define the parameters of existing hydrologic models was adopted. The numerical groundwater flow model is developed to configure the groundwater equipotential surface, hydraulic head gradient, and estimation of the groundwater budget of the aquifer. GIS is used for spatial database development, integration with a remote sensing, and numerical groundwater flow modeling capabilities. The thematic layers of soils, land use, hydrology, infrastructure, and climate were developed using GIS. The Arcview GIS software is used as additive tool to develop supportive data for numerical groundwater flow modeling and integration and presentation of image processing and modeling results. The groundwater flow model was calibrated to simulate future changes in piezometric heads from the period 2006 to 2020. Different scenarios were developed to study the impact of extreme climatic conditions (drought/flood) and variable groundwater abstraction on the regional groundwater system. The model results indicated a significant response in watertable due to external influential factors. The developed model provides an effective tool for evaluating better management options for monitoring future groundwater development in the study area.
Mesoscale circulations in the Los Angeles Basin: A numerical modeling study
Ulrickson, B.L.
1988-01-01
Mesoscale atmospheric forcing in the Los Angeles Basin was investigated by means of a numerical model and observations. Special attention was paid to airflows that are important to the transport of pollutants in the region. The numerical model was modified in order to improve its numerical stability and enhance its accuracy in the context of sharp topographic relief and strong sea/land thermal contrasts. Output from two simulations were compared with observations to document the model's strengths and weaknesses. Overall, the model results compared well with the observations. Large-scale conditions typical of summer and winter smog episodes were discovered by compositing cases described in the literature. Summer and winter simulations were performed, with and without the large-scale winds typical of the summer and winter episodes, and the results were analyzed. Light geostrophic winds were found to have little influence on the strong mesoscale circulations predicted for the summer day, but stronger geostrophic winds exerted considerable influence on the weaker mesoscale circulations that occurred on the winter day.
Biodegradation in numerical basin modelling: a case study from the Gifhorn Trough, N-Germany
NASA Astrophysics Data System (ADS)
Blumenstein, I. O.; Krooss, B. M.; di Primio, R.; Rottke, W.; Müller, E.; Westerlage, C.; Littke, R.
2008-09-01
A mass balance concept based on petroleum compositional description using 14 individual compound groups has been developed to reproduce the process of in-reservoir petroleum biodegradation. Individual compound groups have been attributed different “biodegradabilities” and biodegradation rates to account for observed differences in their susceptibility to biodegradation. Petroleum compositional information is derived from basin modelling, in addition to temperature histories, filling rates and volumetric information. This new method has been subsequently applied to model the biodegradation processes in a petroleum system in the North German Basin. The case study area is situated in the Gifhorn Trough, where Jurassic reservoirs contain oils of variable API gravity (24°-33°), although present depth and temperature are similar. Numerical modelling revealed, however, that the filling histories of the individual reservoir structures differ considerably. Taking into account filling and temperature history of the reservoir structures, the newly developed biodegradation algorithm Biodexx predicted compositional data and API gravities similar to those observed in the study area, whereas earlier biodegradation approaches such as the biodegradation index (BDI) by Yu et al. (2002) did not reproduce the different biodegradation levels in the two investigated fields.
NASA Astrophysics Data System (ADS)
Brown, M. R. M.; Ge, S.; Sheehan, A. F.
2016-12-01
Previous studies have correlated seismicity with high rate injection at Underground Injection Control Class II wastewater disposal wells. In this study, we examine the impact of injection in the Denver Basin combined disposal zone that is used by numerous Class II wells. The disposal zone includes the Lyons Formation, a sandstone unit, and the Fountain Formation, an arkose unit just above the basement. Within a 30-km radius of the deep Class II injection well (NGL C4A) closest to the June 1, 2014 M3.2 Greeley earthquake, there are fifteen deep wastewater disposal wells injecting into the disposal zone and two shallow wastewater disposal wells injecting into the Lyons Formation only. One of the shallow wells is located at the same disposal facility as NGL-C4A and started injection in October 2004; the earliest deep injection in this region, at well NGL-C6, began in November 2007. The major episode of seismicity in the area started in November 2013. The timing of injection operation and seismicity occurrence raises several questions. Why did seismicity not begin in the area until nearly 10 years after the start of injection? Nine of the deep wastewater disposal wells began injection after the M3.2 earthquake on June 1, 2014; how does the large increase in the number of injection wells in the area change the pore-pressure in the disposal zone? How does the injection from the various wells interact? Does this increase the chances of induced seismicity? We conduct numerical modeling of 18 injection wells from 2004 to 2016 to explore these questions by better understanding the pore-pressure changes through time, pore-pressure changes in areas of induced earthquakes, and the interactions between injection wells. We include the asymmetry of the basin geometry in the model. We also use this case study to refine how well spacing and injection rate influences the occurrence of induced earthquakes.
NASA Astrophysics Data System (ADS)
Fernandez, Naiara; Duffy, Oliver B.; Hudec, Michael R.; Jackson, Christopher A.-L.; Dooley, Tim P.; Jackson, Martin P. A.; Burg, George
2017-04-01
The SE Precaspian Basin is characterized by an assemblage of Upper Permian to Triassic minibasins. A recently acquired borehole-constrained 3D reflection dataset reveals the existence of abundant intrasalt reflection packages lying in between the Permo-Triassic minibasins. We propose that most of the mapped intrasalt reflection packages in the study area are minibasins originally deposited on top of salt that were later incorporated into salt by encasement processes. This makes the SE Precaspian Basin a new example of a salt province populated by encased minibasins, which until now had been mainly described from the Gulf of Mexico. Identifying salt-encased sediment packages in the study area has been crucial, not only because they provide a new exploration target, but also because they can play a key role on improving seismic imaging of adjacent or deeper stratigraphic sections. Another remarkable feature observed in the seismic dataset is the widespread occurrence of distinct seismic sequences in the Permo-Triassic minibasins. Bowl- and wedge-shaped seismic sequences define discrete periods of vertical and asymmetric minibasin subsidence. In the absence of shortening, the bowl-to-wedge transition is typically associated with the timing of basal welding and subsequent rotation of the minibasins. Timing of minibasin welding has important implications when addressing the likelihood of suprasalt reservoir charging. We performed a set of 2D numerical simulations aimed at investigating what drives the tilting of minibasins and how it relates to welding. A key observation from the numerical models is that the bowl-to-wedge transition can predate the time of basal welding.
Numerical Analysis Of Flows With FIDAP
NASA Technical Reports Server (NTRS)
Sohn, Jeong L.
1990-01-01
Report presents an evaluation of accuracy of Fluid Dynamics Package (FIDAP) computer program. Finite-element code for analysis of flows of incompressible fluids and transfers of heat in multidimensional domains. Includes both available methods for treatment of spurious numerical coupling between simulated velocity and simulated pressure; namely, penalty method and mixed-interpolation method with variable choices of interpolation polynomials for velocity and pressure. Streamwise upwind (STU) method included as option for flows dominated by convection.
Experimental and numerical analysis of convergent nozzlex
NASA Astrophysics Data System (ADS)
Srinivas, G.; Rakham, Bhupal
2017-05-01
In this paper the main focus was given to convergent nozzle where both the experimental and numerical calculations were carried out with the support of standardized literature. In the recent years the field of air breathing and non-air breathing engine developments significantly increase its performance. To enhance the performance of both the type of engines the nozzle is the one of the component which will play a vital role, especially selecting the type of nozzle depends upon the vehicle speed requirement and aerodynamic behavior at most important in the field of propulsion. The convergent nozzle flow experimental analysis done using scaled apparatus and the similar setup was arranged artificially in the ANSYS software for doing the flow analysis across the convergent nozzle. The consistent calculation analysis are done based on the public literature survey to validate the experimental and numerical simulation results of convergent nozzle. Using these two experimental and numerical simulation approaches the best fit results will bring up to meet the design requirements. However the comparison also made to meet the reliability of the work on design criteria of convergent nozzle which can entrench in the field of propulsion applications.
Transitional behavior of convective patterns in porous media: Insights from basin stability analysis
NASA Astrophysics Data System (ADS)
Karani, Hamid; Huber, Christian
2016-11-01
The present study investigates the transitional behavior of convective modes in Horton-Rogers-Lapwood convection (HRLC). We first provide new pore-scale numerical and experimental evidences on the variation of the stability level of single-cell and double-cell convection modes in a 2D HRLC problem. In order to interpret this transitional behavior, we employ the concept of basin stability and develop a basin stability diagram of the first four convection modes in HRLC. This is in contrast to the standard bifurcation analysis of HRLC using linear stability analysis and continuation techniques, which only provides local information about the (range of) existence, and any possible co-existence of different convection modes. The present basin stability analysis of HRLC not only provides the local information about the (co-)existence of different patterns, but also, it determines their relative stability as well as how the basin of stability of these modes contract or expands as the Rayleigh number varies. The results of the present study show how establishing the dependence of basin stability on the Rayleigh number is essential to analyze the transition between different convection patterns observed experimentally and numerically.
NASA Astrophysics Data System (ADS)
Kim, Yeseul; Lee, Changyeol
2017-04-01
Sedimentation on extensional basins allows fast cooling of the shallow crust because the overlying sediments efficiently transfer heats from the shallow crust to the surface and hinders heat transfer from the underlying deep crust and mantle to the surface, which lowers the surface heat flux (e.g., covering effect). Therefore, it is important to evaluate the impact of transient sedimentation on the thermal structure of the extensional basin. We designed a numerical model which considers transient sedimentation based on the kinematic basin extension formulated by Jarvis and McKenzie (1980). In the model study, we vary duration of extension, stretch factor (β) and sediment thickness of the basin with 100 Myr of cooling since the basin extension ceases. First, we evaluate the effect of duration of extension on the thermal structure of the basin by using the stretch factor (β) and sediment thickness of 2 and 2 km, respectively. Our model calculations show that longer duration of extension results in larger decreases in the geotherm and surface heat flux of the basin. Second, we evaluate the effect of stretch factor (β) on the thermal structure of the basin by using the duration of extension and sediment thickness of 20 Myr and 2 km, respectively. The results indicate that larger stretch factor (β) results in larger decreases in the geotherm and surface heat flux of the basin. Evaluation of the effect of the sediment thickness is ongoing by keeping the duration of extension and stretch factor (β) of 20 Myr and 2, respectively. We will apply our findings to analyze the thermal structure of the Ulleung and Yamato Basins in the East (Japan) Sea.
K basin sludge & water system preliminary hazard analysis
MARTIN, J.B.
2001-09-06
This report provides the initial Preliminary Hazard Analysis (PHA) for the Spent Nuclear Fuel (SNF) Project, Sludge and Water System (SWS) subproject. The purpose of the K East (KE) basins SWS is to provide a system that will transfer the KE basins sludge from in-basin storage or source locations to containment and loadout for subsequent transport to T Plant for storage. The SWS will provide a system (Phase I) to retrieve and contain the identified as-settled sludge volume in the KE basin, while maintaining basin water clarity and associated radioactive control limits in accordance with basin operation requirements, and to support the Fuel Transfer System (FTS) and Debris Removal System (DRS). The SWS will also provide a system (Phase II) to retrieve and contain the remaining as-settled sludge volume in the K East basin, while maintaining basin water clarity and associated radioactive control limits in accordance with basin operation requirements. The SWS is in the conceptual design phase. A primary purpose of this PHA is to support the Conceptual Design Document (draft). As details of the SWS process and design are developed, this initial PHA will require revision. The K Basin Hazard Analysis (HNF-3960) documents the hazard analysis previously performed on the K basins including the multi-canister overpack (MCO) and support buildings. HNF-3960 will be updated later to reflect future SWS activities for sludge and water transfer to ensure that all hazards are included. All operational activities and energy sources associated with the SWS are evaluated in this hazard analysis. Using a systematic approach, this document identifies hazards created by abnormal operating conditions, external events (e.g., range fire), and natural phenomena hazards (e.g., earthquake) with the potential for causing undesirable consequences to facility workers, on-site individuals, the public, or the environment.
Numerical flow analysis for axial flow turbine
NASA Astrophysics Data System (ADS)
Sato, T.; Aoki, S.
Some numerical flow analysis methods adopted in the gas turbine interactive design system, TDSYS, are described. In the TDSYS, a streamline curvature program for axisymmetric flows, quasi 3-D and fully 3-D time marching programs are used respectively for blade to blade flows and annular cascade flows. The streamline curvature method has some advantages in that it can include the effect of coolant mixing and choking flow conditions. Comparison of the experimental results with calculated results shows that the overall accuracy is determined more by the empirical correlations used for loss and deviation than by the numerical scheme. The time marching methods are the best choice for the analysis of turbine cascade flows because they can handle mixed subsonic-supersonic flows with automatic inclusion of shock waves in a single calculation. Some experimental results show that a time marching method can predict the airfoil surface Mach number distribution more accurately than a finite difference method. One weakpoint of the time marching methods is a long computer time; they usually require several times as much CPU time as other methods. But reductions in computer costs and improvements in numerical methods have made the quasi 3-D and fully 3-D time marching methods usable as design tools, and they are now used in TDSYS.
Numerical Analysis of Rocket Exhaust Cratering
NASA Technical Reports Server (NTRS)
2008-01-01
Supersonic jet exhaust impinging onto a flat surface is a fundamental flow encountered in space or with a missile launch vehicle system. The flow is important because it can endanger launch operations. The purpose of this study is to evaluate the effect of a landing rocket s exhaust on soils. From numerical simulations and analysis, we developed characteristic expressions and curves, which we can use, along with rocket nozzle performance, to predict cratering effects during a soft-soil landing. We conducted a series of multiphase flow simulations with two phases: exhaust gas and sand particles. The main objective of the simulation was to obtain the numerical results as close to the experimental results as possible. After several simulating test runs, the results showed that packing limit and the angle of internal friction are the two critical and dominant factors in the simulations.
Numerical analysis of Horvath-Kawazoe equation.
Kowalczyk, P; Terzyk, A P; Gauden, P A; Solarz, L
2002-01-01
A new Determining Horvath-Kawazoe (DHK) program for the evaluation of pore-size distribution curve based on the HK method (J. Chem. Eng. Jpn. 16 (1983) 470) is described. The standard bisection procedure (Gerald, C.F., 1977. Applied Numerical Analysis, 2nd ed. Addison-Wesley, CA) is used as a kernel in the proposed algorithm. The calculation of the effective pore-size distribution and the comparative analysis with the previous data published by Horvath and co-workers (J. Chem. Eng. Jpn. 16 (1983) 470; Fraissard, J., Conner, C.W., 1997. Physical Adsorption: Experiment, Theory and Applications. Kluwer Academic, London) and recalculated by Do (Do, D.D., 1998. Adsorption Analysis: Equilibria and Kinetics. Imperial College Press, London) were done.
The DESIRE Airborne gravity project in the Dead Sea Basin and 3D numerical gravity modeling
NASA Astrophysics Data System (ADS)
Choi, S.; Goetze, H.; Meyer, U.; Group, D.
2008-12-01
This geo-scientific research focuses on the geological setting of the Dead Sea Transform (DST) and the Dead Sea Basin (DSB) and its resulting pull-apart basins. Since the late 1970s, crustal scale geophysical experiments have been carried out in this region. However, the nature of the crust underlying the eastern and western shoulders of the DSB and underneath the DST itself is still a hotly debated topic among researchers. To address one of the central questions of plate tectonics - How do large transform systems work and what are their typical features? - An international geoscientific Dead Sea Integrated Research project (DESIRE) is being conducted by colleagues from Germany, Israel, Palestine, and Jordan. In order to provide a high resolution gravity database that support 3D numerical modeling and hence a more comprehensive understanding of the nature and segmentation of the DST, an airborne gravity survey as a part of the DESIRE project has been carried out from February to March 2007. The airborne gravity survey covered the DST from Elat/Aqaba in the South to the northern rim of the Dead Sea. The low speed and terrain-following helicopter gravity flights were performed to acquire the highest possible data quality. In total, 32 north-south profiles and 16 west-east profiles crossing the DST have been measured. Most of the profiles concentrated in areas that lacked terrestrial gravity data coverage, e. g. over the shoulders of the DSB. The airborne gravity data are merged with existing conventional (terrestrial) data sets to provide a seamless gravity map of the area of interest. Using that combined gravity dataset and DESIRE wide angle refractions seismic interpretation we modified density structures in the DSB. As results we estimated that (1) the Moho depth varies from 26 km in the Israel side to 34 km in the Jordan side. (2) The maximum thickness of the Dead Sea sediment Basin is about 15 km. (3) The salt rock with an average thickness of about 5 km is
Numerical analysis method for linear induction machines.
NASA Technical Reports Server (NTRS)
Elliott, D. G.
1972-01-01
A numerical analysis method has been developed for linear induction machines such as liquid metal MHD pumps and generators and linear motors. Arbitrary phase currents or voltages can be specified and the moving conductor can have arbitrary velocity and conductivity variations from point to point. The moving conductor is divided into a mesh and coefficients are calculated for the voltage induced at each mesh point by unit current at every other mesh point. Combining the coefficients with the mesh resistances yields a set of simultaneous equations which are solved for the unknown currents.
Numerical and experimental analysis of spallation phenomena
NASA Astrophysics Data System (ADS)
Martin, Alexandre; Bailey, Sean C. C.; Panerai, Francesco; Davuluri, Raghava S. C.; Zhang, Huaibao; Vazsonyi, Alexander R.; Lippay, Zachary S.; Mansour, Nagi N.; Inman, Jennifer A.; Bathel, Brett F.; Splinter, Scott C.; Danehy, Paul M.
2016-12-01
The spallation phenomenon was studied through numerical analysis using a coupled Lagrangian particle tracking code and a hypersonic aerothermodynamics computational fluid dynamics solver. The results show that carbon emission from spalled particles results in a significant modification of the gas composition of the post-shock layer. Results from a test campaign at the NASA Langley HYMETS facility are presented. Using an automated image processing of short exposure images, two-dimensional velocity vectors of the spalled particles were calculated. In a 30-s test at 100 W/cm2 of cold-wall heat flux, more than 722 particles were detected, with an average velocity of 110 m/s.
Numerical analysis method for linear induction machines.
NASA Technical Reports Server (NTRS)
Elliott, D. G.
1972-01-01
A numerical analysis method has been developed for linear induction machines such as liquid metal MHD pumps and generators and linear motors. Arbitrary phase currents or voltages can be specified and the moving conductor can have arbitrary velocity and conductivity variations from point to point. The moving conductor is divided into a mesh and coefficients are calculated for the voltage induced at each mesh point by unit current at every other mesh point. Combining the coefficients with the mesh resistances yields a set of simultaneous equations which are solved for the unknown currents.
Hybrid Experimental-Numerical Stress Analysis.
1983-04-01
tension testings of excised strips of the cornea (17] and the sclera E18 ] yielded erroneous modulus of elasticity and Poisson’s ratio by the...Clarke, ASTM 51? 668, 1979, pp. 121 -150. D. Lndet J A.Begley and G. A. Clarke, ASTM STP 668v 1979P pp. 65 - 120. 28. Wilson# W. K., and Oslas, 3. R...Paris, ASTM STP 700, 1900, pp. 174 - 188. 33. Nishioka, T. and Atluri, S. N., "Numerical Analysis of Dynamic Crack Propagation: Generation and
Numerical and experimental analysis of a retrievable offshore loading facility
Sterndorff, M.J.; O`Brien, P.
1995-12-31
ROLF (Retrievable Offshore Loading Facility) has been proposed as an alternative offshore oil export tanker loading system for the North Sea. The system consists of a flexible riser ascending from the seabed in a lazy wave configuration to the bow of a dynamically positioned tanker. In order to supplant and support the numerical analyses performed to design the system, an extensive model test program was carried out in a 3D offshore basin at scale 1:50. A model riser with properties equivalent to the properties of the oil filled prototype riser installed in seawater was tested in several combinations of waves and current. During the tests the forces at the bow of the tanker and at the pipeline end manifold were measured together with the motions of the tanker and the riser. The riser motions were measured by means of a video based 3D motion monitoring system. Of special importance was accurate determination of the minimum bending radius for the riser. This was derived based on the measured riser motions. The results of the model tests were compared to numerical analyses by an MCS proprietary riser analysis program.
Low noise propeller design using numerical analysis
NASA Astrophysics Data System (ADS)
Humpert, Bryce
The purpose of this study is to explore methods for reducing aircraft propeller noise with minimal losses in performance. Using numerical analysis, a standard two blade propeller configuration was taken from experiments conducted by Patrick, Finn, and Stich, and implemented into the numerical code XROTOR. The blade design modifications that were investigated to achieve the proposed goals include: increasing the number of blades, adjusting the chord length, beta distribution, radius of the blade, airfoil shape, and operating RPM. In order to determine the optimal blade design, a baseline case is first developed and the parameters listed earlier are then varied to create a new propeller design that reduces the sound pressure level (SPL) while maintaining performance levels within a predetermined range of the original specifications. From the analysis, the most significant improvements observed in lowering the acoustic signature are dominated by operating rpm and blade radius. A three-, four-, and five-blade configuration was developed that reduced the SPL generated by the propeller during cruise flight conditions. The optimum configuration that produced the greatest SPL reduction was the five-blade configuration. The resulting sound pressure level was reduced from the original 77 dB at 1000' ft above ground level (AGL), to 54 dB at 1000' AGL while remaining within 1.4% of the original thrust and efficiency.
Mapping Sedimentary Basins Across Canada Using Receiver Function Analysis
NASA Astrophysics Data System (ADS)
Cassidy, J. F.; Kao, H.; Kim, H.; Dehler, S.; Dosso, S.; Halliday, J.
2008-12-01
Receiver function studies are being applied within several sedimentary basins across Canada to map basin geometry and sediment thickness. Teleseismic receiver functions are ideal, in many ways, for this type of study. They provide site-specific information, constraints on the shear wave velocity, interface geometry, and they can be used to identify structures from the near-surface to mantle depths. Although the frequency content of teleseismic waveforms limits the resolution, high-frequency receiver functions can resolve layers as thin as 1-2 km. In the Western Canada Sedimentary Basin (near Edmonton, Alberta), receiver functions were used to image the 2.5-km-thick sedimentary package at this site and a low-velocity zone in the upper crust. Currently, a deployment of 10 broadband seismic stations in Atlantic Canada is targeting the Paleozoic and Carboniferous sedimentary basins in the Gulf of St. Lawrence. Significant variations in the arrival time of the continental Moho phase along a north-south transect indicate crustal thickness variations, with the earliest Moho arrivals being in the central part of the basin, indicating a thinner crust here. The direct arrivals in the receiver functions at stations in the southern part of the gulf are broad, indicating notable thicknesses of near-surface sediments. These observations are consistent with what is known about the regional geology and the centrally-located Maritimes Basin. These initial observations, and other geophysical data for the region, will feed into interpretations of crustal structure developed through numerical modelling.In the Nechako Basin of central BC, receiver functions from seven broadband seismograph stations are being used to map sediments in this basin that are overlain by volcanic basalts. These receiver function show clear evidence for shallow dipping low-velocity layers. Constrains on the basin geometry and sediment thickness will be used to improve assessments of oil and gas potential in
Nozzle Numerical Analysis Of The Scimitar Engine
NASA Astrophysics Data System (ADS)
Battista, F.; Marini, M.; Cutrone, L.
2011-05-01
This work describes part of the activities on the LAPCAT-II A2 vehicle, in which starting from the available conceptual vehicle design and the related pre- cooled turbo-ramjet engine called SCIMITAR, well- thought assumptions made for performance figures of different components during the iteration process within LAPCAT-I will be assessed in more detail. In this paper it is presented a numerical analysis aimed at the design optimization of the nozzle contour of the LAPCAT A2 SCIMITAR engine designed by Reaction Engines Ltd. (REL) (see Figure 1). In particular, nozzle shape optimization process is presented for cruise conditions. All the computations have been carried out by using the CIRA C3NS code in non equilibrium conditions. The effect of considering detailed or reduced chemical kinetic schemes has been analyzed with a particular focus on the production of pollutants. An analysis of engine performance parameters, such as thrust and combustion efficiency has been carried out.
Numerical Analysis of Convection/Transpiration Cooling
NASA Technical Reports Server (NTRS)
Glass, David E.; Dilley, Arthur D.; Kelly, H. Neale
1999-01-01
An innovative concept utilizing the natural porosity of refractory-composite materials and hydrogen coolant to provide CONvective and TRANspiration (CONTRAN) cooling and oxidation protection has been numerically studied for surfaces exposed to a high heat flux high temperature environment such as hypersonic vehicle engine combustor walls. A boundary layer code and a porous media finite difference code were utilized to analyze the effect of convection and transpiration cooling on surface heat flux and temperature. The boundary layer code determined that transpiration flow is able to provide blocking of the surface heat flux only if it is above a minimum level due to heat addition from combustion of the hydrogen transpirant. The porous media analysis indicated that cooling of the surface is attained with coolant flow rates that are in the same range as those required for blocking, indicating that a coupled analysis would be beneficial.
Numerical Analysis of Convection/Transpiration Cooling
NASA Technical Reports Server (NTRS)
Glass, David E.; Dilley, Arthur D.; Kelly, H. Neale
1999-01-01
An innovative concept utilizing the natural porosity of refractory-composite materials and hydrogen coolant to provide CONvective and TRANspiration (CONTRAN) cooling and oxidation protection has been numerically studied for surfaces exposed to a high heat flux, high temperature environment such as hypersonic vehicle engine combustor walls. A boundary layer code and a porous media finite difference code were utilized to analyze the effect of convection and transpiration cooling on surface heat flux and temperature. The boundary, layer code determined that transpiration flow is able to provide blocking of the surface heat flux only if it is above a minimum level due to heat addition from combustion of the hydrogen transpirant. The porous media analysis indicated that cooling of the surface is attained with coolant flow rates that are in the same range as those required for blocking, indicating that a coupled analysis would be beneficial.
Dynamic Numerical Analysis of Steel Footbridge
NASA Astrophysics Data System (ADS)
Major, Maciej; Minda, Izabela; Major, Izabela
2017-06-01
The study presents a numerical analysis of the arched footbridge designed in two variants, made of steel and aluminium. The first part presents the criteria for evaluation of the comfort of using the footbridges. The study examined the footbridge with arched design with span in the axis of 24 m and width of 1.4 m. Arch geometry was made as a part of the circle with radius of r = 20 m cut off with a chord with length equal to the calculation length of the girders. The model of the analysed footbridge was subjected to the dynamic effect of wind and the pedestrian traffic with variable flexibility. The analyses used Robot Structural Analysis software.
A theoretical analysis of basin-scale groundwater temperature distribution
NASA Astrophysics Data System (ADS)
An, Ran; Jiang, Xiao-Wei; Wang, Jun-Zhi; Wan, Li; Wang, Xu-Sheng; Li, Hailong
2015-03-01
The theory of regional groundwater flow is critical for explaining heat transport by moving groundwater in basins. Domenico and Palciauskas's (1973) pioneering study on convective heat transport in a simple basin assumed that convection has a small influence on redistributing groundwater temperature. Moreover, there has been no research focused on the temperature distribution around stagnation zones among flow systems. In this paper, the temperature distribution in the simple basin is reexamined and that in a complex basin with nested flow systems is explored. In both basins, compared to the temperature distribution due to conduction, convection leads to a lower temperature in most parts of the basin except for a small part near the discharge area. There is a high-temperature anomaly around the basin-bottom stagnation point where two flow systems converge due to a low degree of convection and a long travel distance, but there is no anomaly around the basin-bottom stagnation point where two flow systems diverge. In the complex basin, there are also high-temperature anomalies around internal stagnation points. Temperature around internal stagnation points could be very high when they are close to the basin bottom, for example, due to the small permeability anisotropy ratio. The temperature distribution revealed in this study could be valuable when using heat as a tracer to identify the pattern of groundwater flow in large-scale basins. Domenico PA, Palciauskas VV (1973) Theoretical analysis of forced convective heat transfer in regional groundwater flow. Geological Society of America Bulletin 84:3803-3814
NASA Astrophysics Data System (ADS)
Juza, Mélanie; Mourre, Baptiste; Lellouche, Jean-Michel; Tonani, Marina; Tintoré, Joaquin
2015-09-01
This study describes a quantitative evaluation of simulations in the western Mediterranean Sea at basin and sub-basin scales. The Mediterranean Forecasting System and the Mercator-Océan simulations provide operational ocean forecasts and hindcasts in the Mediterranean, and are also used as initial and boundary conditions for regional models. In this context, hindcast simulations from 2009 to 2012 are compared with available multi-platform observations at various spatial and temporal scales to evaluate their performance. Both simulations reproduce well the observed mean conditions and variability over the last years. The sub-basin scale analyses of the three-dimensional ocean structures and water mass properties reveal seasonal and regional temperature and salinity errors at the surface in both simulations, as well as significant biases at intermediate and deep layers in the Mediterranean Forecasting System. The simulated surface geostrophic velocities are weaker than those derived from altimetry, and circulation biases persist in the Balearic Sea. Additionally, the seasonal existence of the Alboran gyres is not well reproduced in either simulation. The identification of regional simulation biases is essential to advance from global to regional and local scale forecasting, in particular, improving the representation of the local physical processes and their interactions with the sub-basin dynamics and the general circulation.
Numerical modeling of tidal notch sequences on rocky coasts of the Mediterranean Basin
NASA Astrophysics Data System (ADS)
Schneiderwind, S.; Boulton, S. J.; Papanikolaou, I.; Kázmér, M.; Reicherter, K.
2017-05-01
Tidal notches have had the potential to form at sea level from 6.5 kyr B.P. in the Mediterranean Basin and preserve a symmetrical shape comparable to a quadric polynomial. Continuous erosion, predominantly by biological agents, affects a limestone cliff face from low- to high-tide level at <1 mm/yr. Statically determined, the roots of a quadric polynomial are defined by the tidal range representing the limits of effective erosion. However, gradual variations of eustatic sea level rise (slow) and coseismic uplift/subsidence (fast) in tectonically active regions contribute to vertical shifts in the erosional base at coastlines. As a consequence, the cliff morphology gets modified through time resulting in widening, deepening, and separation of notches and possible overprinting of older features. In order to investigate successive modifications of coastal cliff morphology, we developed a numerical model that considers the erosion rate, the erosion zone relative to sea level, the regional sea level curve, and tectonic motion. The results show how slow and rapid sea level changes bias the modern cliff face and highlight that the present-day notch sequence from top descending to sea level is not inevitably of decreasing age. Furthermore, the initiation of notch formation is not necessarily linked to the date of a certain seismic event. Especially in extensional tectonic settings where coseismic uplift is low and coastal morphological marks are not as distinct, knowledge about coastal evolution is beneficial for paleoseismological research.
Numerical modeling techniques for flood analysis
NASA Astrophysics Data System (ADS)
Anees, Mohd Talha; Abdullah, K.; Nawawi, M. N. M.; Ab Rahman, Nik Norulaini Nik; Piah, Abd. Rahni Mt.; Zakaria, Nor Azazi; Syakir, M. I.; Mohd. Omar, A. K.
2016-12-01
Topographic and climatic changes are the main causes of abrupt flooding in tropical areas. It is the need to find out exact causes and effects of these changes. Numerical modeling techniques plays a vital role for such studies due to their use of hydrological parameters which are strongly linked with topographic changes. In this review, some of the widely used models utilizing hydrological and river modeling parameters and their estimation in data sparse region are discussed. Shortcomings of 1D and 2D numerical models and the possible improvements over these models through 3D modeling are also discussed. It is found that the HEC-RAS and FLO 2D model are best in terms of economical and accurate flood analysis for river and floodplain modeling respectively. Limitations of FLO 2D in floodplain modeling mainly such as floodplain elevation differences and its vertical roughness in grids were found which can be improve through 3D model. Therefore, 3D model was found to be more suitable than 1D and 2D models in terms of vertical accuracy in grid cells. It was also found that 3D models for open channel flows already developed recently but not for floodplain. Hence, it was suggested that a 3D model for floodplain should be developed by considering all hydrological and high resolution topographic parameter's models, discussed in this review, to enhance the findings of causes and effects of flooding.
Numerical Simulation of Ground-Water Withdrawals in the Southern Lihue Basin, Kauai, Hawaii
Izuka, Scot K.; Oki, Delwyn S.
2002-01-01
Numerical simulations indicate that ground-water withdrawals from the Hanamaulu and Puhi areas of the southern Lihue Basin will result in a decline in water levels and reductions in base flows of streams near proposed new water-supply wells. Most of the changes will be attained within 10 to 20 years of the start of pumping. Except for areas such as Puhi and Kilohana, the freshwater lens in most inland areas of the southern Lihue Basin is thick and model simulations indicate that changes in water level and the position of the freshwater- saltwater interface in response to pumping will be small relative to the present thickness of the freshwater lens. Effects of the proposed withdrawals on streamflow depend on withdrawal rate and proximity of the wells to streams. Placing pumped wells away from streams with low base flow and toward streams with high base flow can reduce the relative effect on individual streams. Simulation of the 0.42-million-gallon-per-day increase in withdrawal projected for 2000 indicates that the resulting changes in water levels and interface position, relative to conditions prior to the withdrawal increase, will be small, and that stream base flow will be reduced by less than 10 percent. Simulation of the 0.83-million-gallon-per-day withdrawal projected for 2010 indicates further thinning of the freshwater lens in the Puhi area, where the lens already may be thin, as well as base-flow reduction in Nawiliwili Stream. Simulation of an alternative distribution of the 0.83-million-gallon-per-day withdrawal indicates that the effects can be reduced by shifting most of the new withdrawal to the Hanamaulu area where the freshwater lens is thicker and stream base flows are greater. Simulation of the 1.16-million-gallon-per-day increase in withdrawal projected for 2020 indicates that if withdrawal is distributed only among Hana-maulu wells 1, 3, and 4, and Puhi well 5A, further thinning of the already-thin freshwater lens in the Puhi area would occur
183-H Basin Mixed Waste Analysis and Testing Report
1995-04-01
The purpose of this sampling and analysis report is to provide data necessary to support treatment and disposal options for the low-level mixed waste from the 183-H solar evaporation ponds. In 1973, four of the 16 flocculation and sedimentation basins were designated for use as solar evaporation basins to provide waste reduction by natural evaporation of liquid chemical wastes from the 300 Area fuel fabrication facilities. The primary purpose of this effort is to gather chemical and bulk property data for the waste in the drums/boxes of sediment removed from the basin at Central Waste Complex.
NASA Astrophysics Data System (ADS)
Cédric, Guyonnet-Benaize; Fabrice, Hollender; Maria, Manakou; Alexandros, Savvaidis; Elena, Zargli; Cécile, Cornou; Nikolaos, Veranis; Dimitrios, Raptakis; Artemios, Atzemoglou; Pierre-Yves, Bard; Nikolaos, Theodulidis; Kyriazis, Pitilakis; Emmanuelle, Chaljub
2013-04-01
The Mygdonian basin, located 30 km E-NE close to Thessaloniki, is a typical active tectonic basin, trending E-NW, filled by sediments 200 to 400 m thick. This basin has been chosen as a European experimental site since 1993 (European Commission research projects - EUROSEISTEST). It has been investigated for experimental and theoretical studies on site effects. The Mygdonian basin is currently covered by a permanent seismological network and has been mainly characterized in 2D and 3D with geophysical and geotechnical studies (Bastani et al, 2011; Cadet and Savvaidis, 2011; Gurk et al, 2007; Manakou et al, 2007; Manakou et al, 2010; Pitilakis et al, 1999; Raptakis et al, 2000; Raptakis et al, 2005). All these studies allowed understanding the influence of geological structures and local site conditions on seismic site response. For these reasons, this site has been chosen for a verification exercise for numerical simulations in the framework of an ongoing international collaborative research project (Euroseistest Verification and Validation Project - E2VP). The verification phase has been made using a first 3D geophysical and geotechnical model (Manakou, 2007) about 5 km wide and 15 km long, centered on the Euroseistest site. After this verification phase, it has been decided to update, optimize and extend this model in order to obtain a more detailed model of the 3D geometry of the entire basin, especially the bedrock 3D geometry which can affect drastically the results of numerical simulations for site effect studies. In our study, we build a 3D geological model of the present-day structure of the entire Mygdonian basin. This "precise" model is 12 km wide, 65 km long and is 400 m deep in average. It has been built using geophysical, geotechnical and geological data. The database is heterogeneous and composed of hydrogeological boreholes, seismic refraction surveys, array microtremor measurements, electrical and geotechnical surveys. We propose an integrated
Tularosa Basin Play Fairway Analysis: Water Chemistry
Adam Brandt
2015-12-15
This shapefile contains 409 well data points on Tularosa Basin Water Chemistry, each of which have a location (UTM), temperature, quartz and Potassium/Magnesium geothermometer; as well as concentrations of chemicals like Mn, Fe, Ba, Sr, Cs, Rb, As, NH4, HCO3, SO4, F, Cl, B, SiO2, Mg, Ca, K, Na, and Li.
Numerical flow analysis of hydro power stations
NASA Astrophysics Data System (ADS)
Ostermann, Lars; Seidel, Christian
2017-07-01
For the hydraulic engineering and design of hydro power stations and their hydraulic optimisation, mainly experimental studies of the physical submodel or of the full model at the hydraulics laboratory are carried out. Partially, the flow analysis is done by means of computational fluid dynamics based on 2D and 3D methods and is a useful supplement to experimental studies. For the optimisation of hydro power stations, fast numerical methods would be appropriate to study the influence of a wide field of optimisation parameters and flow states. Among the 2D methods, especially the methods based on the shallow water equations are suitable for this field of application, since a lot of experience verified by in-situ measurements exists because of the widely used application of this method for the problems in hydraulic engineering. As necessary, a 3D model may supplement subsequently the optimisation of the hydro power station. The quality of the results of the 2D method for the optimisation of hydro power plants is investigated by means of the results of the optimisation of the hydraulic dividing pier compared to the results of the 3D flow analysis.
Neotectonics of the Surma Basin, Bangladesh from GPS analysis
NASA Astrophysics Data System (ADS)
Bulbul, M. A. U.
2015-12-01
The Surma Basin is a sub-basin of the Bengal Basin situated at the northeastern corner of Bangladesh. The tectonically-active basin lies at the junction of three tectonic plates: the Indian plate, the Eurasian plate and the Burma platelet. The Surma Basin is bounded on the north by the Shillong Massif, east and southeast by CTFB of the Indo-Burman Ranges, west by the Indian Shield and to the south and southeast it is open to the main part of Bengal Basin. The Surma basin is subsiding at a high rate, which is controlled by flexure loading along the southern margin of the 2-km high Shillong Massif because of Dauki thrust fault system. The objective of this study is to explore and reconstruct the present scenario of the tectonically active zone of the northeastern Bangladesh, identify the active faults, identify the relation between the neotectonic activities and seismicity, relation between neotectonic activities and natural hazards and describe the nature of the possible future earthquakes. The present effort to establish the tectonics of the Surma basin mainly utilizes the horizontal and vertical movements of the area using GPS geodetic data and other constraints on the structure of the region. We also make use historical seismologic data, field geology, and satellite image data. The GPS data has been processed using GAMIT-GLOBK. The analysis of 5 continuous GPS geodetic stations installed in the Surma Basin are combined with published data from the adjacent parts of India. While the area is moving northeast at a rate of 50-52 mm/year relative to ITRF2008 reference frame, it is moving south in an Indian reference frame. The velocities reflect that the Surma Basin being overthrust by both Shillong Plateau from the north and Burmese microplate from the east, respectively. The combined GPS velocity data indicates shortening across Dauki Fault and Indo Burman Ranges at a rate of 7 mm/yr and 18 mm/yr, respectively. The complex anticlinal structures in and around the
Numerical modeling of severe convective storms occurring in the Carpathian Basin
NASA Astrophysics Data System (ADS)
Horváth, Á.; Geresdi, I.; Németh, P.; Csirmaz, K.; Dombai, F.
Squall lines often cause serious damages due to the strong surface outflow, hail, or heavy precipitation in Hungary every summer. Squall lines in the Carpathian Basin can be classified into two main categories: pre-frontal squall-lines and frontal convective lines. In this paper, these two types of severe mesoscale phenomena are investigated using the high resolution numerical weather prediction model, the MM5. The case study for the first type of convective systems occurred on 18th May 2005 when two main convective lines with their embedded severe storms formed daytime and caused high-velocity wind events and extensive damages in the eastern part of Hungary. The second case study is a frontal squall line that hit Budapest on 20th August 2006 and the associated high precipitation (HP) supercells reached the capital of Hungary at same time when the traditional Constitution Day firework began. The consequences were catastrophic: five people were killed and more than one thousand were injured due to the extreme weather. The non-hydrostatic high resolution MM5 model was able to simulate and catch the severe weather events occurred on the days under discussion. Moreover, the model was able to compute the detailed structure of the supercells embedded in thunderstorm lines. By studying the equivalent potential temperature (EPT) fields at lower levels, we state that in the prefrontal case, there is a competition between the supercell thunderstorms for the wet and warm air. A thunderstorm that can collect the wet and warm air from larger area will have longer lifetime and more intense updraft. In the second case, the frontal squall lines, the movement and the behavior of the supercell storms embedded in the line was highly determined by the synoptic-scale motions and less affected by the EPT field of the prefrontal masses.
Sequence Stratigraphy and Frequency Analysis of the Zhada Basin, SW Tibet
NASA Astrophysics Data System (ADS)
Saylor, J. E.; Decelles, P. G.; Quade, J.
2008-12-01
Zhada basin is a large late Miocene - Pleistocene extensional sag basin in the Tethyan Himalaya of southwestern Tibet. Sequence stratigraphy in the basin reveals a long-term tectonic signal in the formation and filling of Zhada basin. The sedimentological record of the Zhada Formation also archives higher frequency cyclical expansion and contraction of a large paleolake. Expansion and contraction of lakes and wetlands has been linked to variability in the strength of the Asian monsoon and thought to be modulated by orbital cyclicity. In order to determine the forcing mechanism for Zhada paleolake expansion and contraction we created a wave form by assigning numerical values to the various depositional environments and applied spectral analysis to this record. Depositional environments in the South Zhada measured section were identified at 0.5 m increments or where the depositional environment changed. The result is a clipped waveform with uneven sample spacing and temporal resolution better than 4,000 yrs. In addition to a peak at 91.7 kyr (95% confidence level), spectral analysis reveals a peak at 22 kyr (85% confidence level). These are within 1/2 bandwidth (6 dB bandwidth = 2.4) of the eccentricity and precession frequencies. The record of Milankovitch cycles in Zhada basin implies that global climate drove lake and wetland expansion and contraction in the southern Tibetan Plateau from the late Miocene to the Pleistocene.
Sedimentary basin analysis using airborne gravity data: a case study from the Bohai Bay Basin, China
NASA Astrophysics Data System (ADS)
Li, Wenyong; Liu, Yanxu; Zhou, Jianxin; Zhou, Xihua; Li, Bing
2016-11-01
In this paper, we discuss the application of an airborne gravity survey to sedimentary basin analysis. Using high-precision airborne gravity data constrained by drilling and seismic data from the Bohai Bay Basin in eastern China, we interpreted faults, structural elements, sedimentary thickness, structural styles and local structures (belts) in the central area of the Basin by the wavelet transform method. Subsequently, these data were subtracted from the Bouguer gravity to calculate the residual gravity anomalies. On this basis, the faults were interpreted mainly by linear zones of high gravity gradients and contour distortion, while the sedimentary thicknesses were computed by the Euler deconvolution. The structural styles were identified by the combination of gravity anomalies and the local structures interpreted by the first vertical derivative of the residual gravity. The results showed evidence for seven faults, one sag and ten new local structure belts.
NASA Astrophysics Data System (ADS)
Niu, Jun; Chen, Ji; Sun, Liqun
2015-07-01
The knowledge of drought evolution characteristics may aid the decision making process in mitigating drought impacts. This study uses a macro-scale hydrological model, Variable Infiltration Capacity (VIC) model, to simulate terrestrial hydrological processes over the Xijiang (West River) basin in South China. Three drought indices, namely standardized precipitation index (SPI), standardized runoff index (SRI), and soil moisture anomaly index (SMAI), are employed to examine the spatio-temporal and evolution features of drought events. SPI, SRI and SMAI represent meteorological drought, hydrological drought and agricultural drought, respectively. The results reveal that the drought severity depicted by SPI and SRI is similar with increasing timescales; SRI is close to that of SPI in the wet season for the Liu River basin as the high-frequency precipitation is conserved more by runoff; the time lags appear between SPI and SRI due to the delay response of runoff to precipitation variability for the You River basin. The case study in 2010 spring drought further shows that the spatio-temporal evolutions are modulated by the basin-scale topography. There is more consistency between meteorological and hydrological droughts for the fan-like basin with a converged river network. For the west area of the Xijiang basin with the high elevation, the hydrological drought severity is less than meteorological drought during the developing stage. The recovery of hydrological and agricultural droughts is slower than that of meteorological drought for basins with a longer mainstream.
Numerical Flow Analysis of Planing Boats
NASA Astrophysics Data System (ADS)
Brucker, Kyle; O'Shea, Thomas; Dommermuth, Douglas; Fu, Thomas
2012-11-01
The focus of this presentation is to describe the recent effort to validate the computer code Numerical Flow Analysis (NFA) for the prediction of hydrodynamic forces and moments associated with deep-V planing craft. This detailed validation effort was composed of two parts. The first part focuses on assessing NFA's ability to predict pressures on the surface of a 10 degree deadrise wedge during impact with an undisturbed free surface. Detailed comparisons to pressure gauges are presented for two different drop heights, 6 inches and 10 inches. Results show NFA accurately predicted pressures during the slamming event. The second part of the validation study focused on assessing how well NFA was able to accurately model the complex multiphase flow associated with high Froude number flows, specifically the formation of the spray sheet. NFA simulations of a planing hull fixed at various angles of roll (0 degrees, 10 degrees, 20 degrees, and 30 degrees) were compared to experiments from Judge (2012). Comparisons to underwater photographs illustrate NFA's ability to model the formation of the spray sheet and the free surface turbulence associated with planing boat hydrodynamics.
Nonclassicality thresholds for multiqubit states: Numerical analysis
Gruca, Jacek; Zukowski, Marek; Laskowski, Wieslaw; Kiesel, Nikolai; Wieczorek, Witlef; Weinfurter, Harald; Schmid, Christian
2010-07-15
States that strongly violate Bell's inequalities are required in many quantum-informational protocols as, for example, in cryptography, secret sharing, and the reduction of communication complexity. We investigate families of such states with a numerical method which allows us to reveal nonclassicality even without direct knowledge of Bell's inequalities for the given problem. An extensive set of numerical results is presented and discussed.
Seismic stratigraphy and regional unconformity analysis of Chukchi Sea Basins
NASA Astrophysics Data System (ADS)
Agasheva, Mariia; Karpov, Yury; Stoupakova, Antonina; Suslova, Anna
2017-04-01
Russian Chukchi Sea Shelf one of petroleum potential province and still one of the most uninvestigated area. North and Sough Chukchi Trough that separated by Wrangel-Hearld Arch have different origin. The main challenge is stratigraphic sequences determination that filled North and South Chukchi basins. The joint tectonic evolution of the territory as Canada basin opening and Brooks Range-Wrangel Herald orogenic events enable to expect the analogous stratigraphy sequences in Russian Part. Analysis of 2D seismic data of Russian and American Chukchi Sea represent the major seismic reflectance that traced throughout the basins. Referring to this data North Chukchi basin includes four seismic stratigraphic sequences - Franklian (pre-Mississippian), Ellesmirian (Upper Devonian-Jurassic), Beaufortian (Jurassic-Lower Cretaceous) and Brookian (Lower Cretaceous-Cenozoic), as it is in North Slope Alaska [1]. South Chukchi basin has different tectonic nature, representing only Franclian basement and Brookian sequences. Sedimentary cover of North Chukchi basins starts with Ellesmirian sequence it is marked by bright reflector that separates from chaotic folded Franklian sequence. Lower Ellesmirian sequence fills of grabens that formed during upper Devonian rifting. Devonian extension event was initiated as a result of Post-Caledonian orogenic collapse, terminating with the opening of Arctic oceans. Beaufortian sequence is distinguished in Colville basin and Hanna Trough by seismically defined clinoforms. Paleozoic and Mesozoic strata are eroded by regional Lower Cretaceous Unconformity (LCU) linked with Canada basin opening. LCU is defined at seismic by angular unconformity, tracing at most arctic basins. Lower Cretaceous erosion and uplift event are of Hauterivian to Aptian age in Brooks Range and the Loppa High uplift refer to the early Barremian. The Lower Cretaceous clinoform complex downlaps to LCU horizon and filling North Chukchi basin (as in Colville basin Alska
Microfabric analysis of the Appalachian basin Williamson and Willowvale shales
Burkins, D.L.; Woodard, M. . Geology Dept.)
1993-03-01
Shale samples from the Williamson and Willovale formations (Upper Llandoverian, Silurian) were studied to determine the relationship of microfabric (particle orientation) to sedimentary environment and processes. The shales were sampled along a traverse from Utica to Rochester, New York in the Appalachian foreland basin. Samples were taken from proximal and distal parts of the basin and analyzed using a scanning electron microscope (SEM) and using thin sections to determine the relationship between microfabric and basin position. Results show samples taken from the proximal part of the basin contain large amounts of silt grains, random orientation of clay flakes, and a high degree of bioturbation. Basinward, the samples become less silty, less bioturbated, and have more preferred orientation of clay flakes. The samples at the basin axis show the highest degree of preferred orientation and contain no silt grains. It can be concluded that the shale fabrics vary basinward and microfabric analysis is useful in determining the relative position of samples within a sedimentary basin.
Morphometric analysis of the Marmara Sea river basins, Turkey
NASA Astrophysics Data System (ADS)
Elbaşı, Emre; Ozdemir, Hasan
2014-05-01
The drainage basin, the fundamental unit of the fluvial landscape, has been focus of research aimed at understanding the geometric characteristics of the master channel and its tributary network. This geometry is referred to as the basin morphometry and is nicely reviewed by Abrahams (1984). A great amount of research has focused on geometric characteristic of drainage basins, including the topology of the stream networks, and quantitative description of drainage texture, pattern, shape, and relief characteristics. Evaluation of morphometric parameters necessitates the analysis of various drainage parameters such as ordering of the various streams, measurement of basin area and perimeter, length of drainage channels, drainage density (Dd), stream frequency (Fs), bifurcation ratio (Rb), texture ratio (T), basin relief (Bh), Ruggedness number (Rn), time of concentration (Tc), hypsometric curve and integral (Hc and Hi) (Horton, 1932, Schumn, 1956, Strahler, 1957; Verstappen 1983; Keller and Pinter, 2002; Ozdemir and Bird, 2009). These morphometric parameters have generally been used to predict flood peaks, to assess sediment yield, and to estimate erosion rates in the basins. River basins of the Marmara Sea, has an area of approximately 40,000 sqkm, are the most important basins in Turkey based on their dense populations, industry and transportation systems. The primary aim of this study is to determine and analyse of morphometric characteristics of the Marmara Sea river basins using 10 m resolution Digital Elevation Model (DEM) and to evaluate of the results. For these purposes, digital 10 m contour maps scaled 1:25000 and geological maps scaled 1:100000 were used as the main data sources in the study. 10 m resolution DEM data were created using the contour maps and then drainage networks and their watersheds were extracted using D8 pour point model. Finally, linear, areal and relief morphometries were applied to the river basins using Geographic Information Systems
Status of NINJA: the Numerical INJection Analysis project
NASA Astrophysics Data System (ADS)
Cadonati, Laura; Aylott, Benjamin; Baker, John G.; Boggs, William D.; Boyle, Michael; Brady, Patrick R.; Brown, Duncan A.; Brügmann, Bernd; Buchman, Luisa T.; Buonanno, Alessandra; Camp, Jordan; Campanelli, Manuela; Centrella, Joan; Chatterji, Shourov; Christensen, Nelson; Chu, Tony; Diener, Peter; Dorband, Nils; Etienne, Zachariah B.; Faber, Joshua; Fairhurst, Stephen; Farr, Benjamin; Fischetti, Sebastian; Guidi, Gianluca; Goggin, Lisa M.; Hannam, Mark; Herrmann, Frank; Hinder, Ian; Husa, Sascha; Kalogera, Vicky; Keppel, Drew; Kidder, Lawrence E.; Kelly, Bernard J.; Krishnan, Badri; Laguna, Pablo; Lousto, Carlos O.; Mandel, Ilya; Marronetti, Pedro; Matzner, Richard; McWilliams, Sean T.; Matthews, Keith D.; Mercer, R. Adam; Mohapatra, Satyanarayan R. P.; Mroué, Abdul H.; Nakano, Hiroyuki; Ochsner, Evan; Pan, Yi; Pekowsky, Larne; Pfeiffer, Harald P.; Pollney, Denis; Pretorius, Frans; Raymond, Vivien; Reisswig, Christian; Rezzolla, Luciano; Rinne, Oliver; Robinson, Craig; Röver, Christian; Santamaría, Lucía; Sathyaprakash, Bangalore; Scheel, Mark A.; Schnetter, Erik; Seiler, Jennifer; Shapiro, Stuart L.; Shoemaker, Deirdre; Sperhake, Ulrich; Stroeer, Alexander; Sturani, Riccardo; Tichy, Wolfgang; Liu, Yuk Tung; van der Sluys, Marc; van Meter, James R.; Vaulin, Ruslan; Vecchio, Alberto; Veitch, John; Viceré, Andrea; Whelan, John T.; Zlochower, Yosef
2009-06-01
The 2008 NRDA conference introduced the Numerical INJection Analysis project (NINJA), a new collaborative effort between the numerical relativity community and the data analysis community. NINJA focuses on modeling and searching for gravitational wave signatures from the coalescence of binary system of compact objects. We review the scope of this collaboration and the components of the first NINJA project, where numerical relativity groups, shared waveforms and data analysis teams applied various techniques to detect them when embedded in colored Gaussian noise.
NASA Astrophysics Data System (ADS)
Benaïchouche, Abed; Stab, Olivier; Tessier, Bruno; Cojan, Isabelle
2016-01-01
In landscapes dominated by fluvial erosion, the landscape morphology is closely related to the hydrographic network system. In this paper, we investigate the hydrographic network reorganization caused by a headward piracy mechanism between two drainage basins in France, the Meuse and the Moselle. Several piracies occurred in the Meuse basin during the past one million years, and the basin's current characteristics are favorable to new piracies by the Moselle river network. This study evaluates the consequences over the next several million years of a relative lowering of the Moselle River (and thus of its basin) with respect to the Meuse River. The problem is addressed with a numerical modeling approach (landscape evolution model, hereafter LEM) that requires empirical determinations of parameters and threshold values. Classically, fitting of the parameters is based on analysis of the relationship between the slope and the drainage area and is conducted under the hypothesis of equilibrium. Application of this conventional approach to the capture issue yields incomplete results that have been consolidated by a parametric sensitivity analysis. The LEM equations give a six-dimensional parameter space that was explored with over 15,000 simulations using the landscape evolution model GOLEM. The results demonstrate that stream piracies occur in only four locations in the studied reach near the city of Toul. The locations are mainly controlled by the local topography and are model-independent. Nevertheless, the chronology of the captures depends on two parameters: the river concavity (given by the fluvial advection equation) and the hillslope erosion factor. Thus, the simulations lead to three different scenarios that are explained by a phenomenon of exclusion or a string of events.
NASA Astrophysics Data System (ADS)
Ings, Steven; Albertz, Markus
2014-05-01
Deformation of salt and sediments owing to the flow of weak evaporites is a common phenomenon in sedimentary basins worldwide, and the resulting structures and thermal regimes have a significant impact on hydrocarbon exploration. Evaporite sequences ('salt') of significant thickness (e.g., >1km) are typically deposited in many cycles of seawater inundation and evaporation in restricted basins resulting in layered autochthonous evaporite packages. However, analogue and numerical models of salt tectonics typically treat salt as a homogeneous viscous material, often with properties of halite, the weakest evaporite. In this study, we present results of two-dimensional plane-strain numerical experiments designed to illustrate the effects of variable evaporite viscosity and embedded frictional-plastic ('brittle') sediment layers on the style of salt flow and associated deformation of the sedimentary overburden. Evaporite viscosity is a first-order control on salt flow rate and the style of overburden deformation. Near-complete evacuation of low-viscosity salt occurs beneath expulsion basins, whereas significant salt is trapped when viscosity is high. Embedded frictional-plastic sediment layers (with finite yield strength) partition salt flow and develop transient contractional structures (folds, thrust faults, and folded faults) in a seaward salt-squeeze flow regime. Multiple internal sediment layers reduce the overall seaward salt flow during sediment aggradation, leaving more salt behind to be re-mobilized during subsequent progradation. This produces more seaward extensive allochthonous salt sheets. If there is a density difference between the embedded layers and the surrounding salt, then the embedded layers 'fractionate' during deformation and either float to the surface or sink to the bottom (depending on density), creating a thick zone of pure halite. Such a process of 'buoyancy fractionation' may partially explain the apparent paradox of layered salt in
NASA Astrophysics Data System (ADS)
Zodiatis, George; Radhakrishnan, Hari; Lardner, Robin; Hayes, Daniel; Gertman, Isaac; Menna, Milena; Poulain, Pierre-Marie
2014-05-01
The general anticlockwise circulation along the coastline of the Eastern Mediterranean Levantine Basin was first proposed by Nielsen in 1912. Half a century later the schematic of the circulation in the area was enriched with sub-basin flow structures. In late 1980s, a more detailed picture of the circulation composed of eddies, gyres and coastal-offshore jets was defined during the POEM cruises. In 2005, Millot and Taupier-Letage have used SST satellite imagery to argue for a simpler pattern similar to the one proposed almost a century ago. During the last decade, renewed in-situ multi-platforms investigations under the framework of CYBO, CYCLOPS, NEMED, GROOM, HaiSec and PERSEUS projects, as well the development of the operational ocean forecasts and hindcasts in the framework of the MFS, ECOOP, MERSEA and MyOcean projects, have made possible to obtain an improved, higher spatial and temporal resolution picture of the circulation in the area. After some years of scientific disputes on the circulation pattern of the region, the new in-situ data sets and the operational numerical simulations confirm the relevant POEM results. The existing POM-based Cyprus Coastal Ocean Forecasting System (CYCOFOS), downscaling the MyOcean MFS, has been providing operational forecasts in the Eastern Mediterranean Levantine Basin region since early 2002. Recently, Radhakrishnan et al. (2012) parallelized the CYCOFOS hydrodynamic flow model using MPI to improve the accuracy of predictions while reducing the computational time. The parallel flow model is capable of modeling the Eastern Mediterranean Levantine Basin flow at a resolution of 500 m. The model was run in hindcast mode during which the innovations were computed using the historical data collected using gliders and cruises. Then, DD-OceanVar (D'Amore et al., 2013), a data assimilation tool based on 3DVAR developed by CMCC was used to compute the temperature and salinity field corrections. Numerical modeling results after the
Fractal Analysis of Drainage Basins on Mars
NASA Technical Reports Server (NTRS)
Stepinski, T. F.; Marinova, M. M.; McGovern, P. J.; Clifford, S. M.
2002-01-01
We used statistical properties of drainage networks on Mars as a measure of martian landscape morphology and an indicator of landscape evolution processes. We utilize the Mars Orbiter Laser Altimeter (MOLA) data to construct digital elevation maps (DEMs) of several, mostly ancient, martian terrains. Drainage basins and channel networks are computationally extracted from DEMs and their structures are analyzed and compared to drainage networks extracted from terrestrial and lunar DEMs. We show that martian networks are self-affine statistical fractals with planar properties similar to terrestrial networks, but vertical properties similar to lunar networks. The uniformity of martian drainage density is between those for terrestrial and lunar landscapes. Our results are consistent with the roughening of ancient martian terrains by combination of rainfall-fed erosion and impacts, although roughening by other fluvial processes cannot be excluded. The notion of sustained rainfall in recent Mars history is inconsistent with our findings.
Fractal Analysis of Drainage Basins on Mars
NASA Technical Reports Server (NTRS)
Stepinski, T. F.; Marinova, M. M.; McGovern, P. J.; Clifford, S. M.
2002-01-01
We used statistical properties of drainage networks on Mars as a measure of martian landscape morphology and an indicator of landscape evolution processes. We utilize the Mars Orbiter Laser Altimeter (MOLA) data to construct digital elevation maps (DEMs) of several, mostly ancient, martian terrains. Drainage basins and channel networks are computationally extracted from DEMs and their structures are analyzed and compared to drainage networks extracted from terrestrial and lunar DEMs. We show that martian networks are self-affine statistical fractals with planar properties similar to terrestrial networks, but vertical properties similar to lunar networks. The uniformity of martian drainage density is between those for terrestrial and lunar landscapes. Our results are consistent with the roughening of ancient martian terrains by combination of rainfall-fed erosion and impacts, although roughening by other fluvial processes cannot be excluded. The notion of sustained rainfall in recent Mars history is inconsistent with our findings.
NASA Astrophysics Data System (ADS)
Mohite, A. R.; Beria, H.; Behera, A. K.; Chatterjee, C.; Singh, R.
2016-12-01
Flood forecasting using hydrological models is an important and cost-effective non-structural flood management measure. For forecasting at short lead times, empirical models using real-time precipitation estimates have proven to be reliable. However, their skill depreciates with increasing lead time. Coupling a hydrologic model with real-time rainfall forecasts issued from numerical weather prediction (NWP) systems could increase the lead time substantially. In this study, we compared 1-5 days precipitation forecasts from India Meteorological Department (IMD) Multi-Model Ensemble (MME) with European Center for Medium Weather forecast (ECMWF) NWP forecasts for over 86 major river basins in India. We then evaluated the hydrologic utility of these forecasts over Basantpur catchment (approx. 59,000 km2) of the Mahanadi River basin. Coupled MIKE 11 RR (NAM) and MIKE 11 hydrodynamic (HD) models were used for the development of flood forecast system (FFS). RR model was calibrated using IMD station rainfall data. Cross-sections extracted from SRTM 30 were used as input to the MIKE 11 HD model. IMD started issuing operational MME forecasts from the year 2008, and hence, both the statistical and hydrologic evaluation were carried out from 2008-2014. The performance of FFS was evaluated using both the NWP datasets separately for the year 2011, which was a large flood year in Mahanadi River basin. We will present figures and metrics for statistical (threshold based statistics, skill in terms of correlation and bias) and hydrologic (Nash Sutcliffe efficiency, mean and peak error statistics) evaluation. The statistical evaluation will be at pan-India scale for all the major river basins and the hydrologic evaluation will be for the Basantpur catchment of the Mahanadi River basin.
Ground water budget analysis and cross-formational leakage in an arid basin.
Hutchison, William R; Hibbs, Barry J
2008-01-01
Ground water budget analysis in arid basins is substantially aided by integrated use of numerical models and environmental isotopes. Spatial variability of recharge, storage of water of both modern and pluvial age, and complex three-dimensional flow processes in these basins provide challenges to the development of a good conceptual model. Ground water age dating and mixing analysis with isotopic tracers complement standard hydrogeologic data that are collected and processed as an initial step in the development and calibration of a numerical model. Environmental isotopes can confirm or refute a priori assumptions of ground water flow, such as the general assumption that natural recharge occurs primarily along mountains and mountain fronts. Isotopes also serve as powerful tools during postaudits of numerical models. Ground water models provide a means of developing ground water budgets for entire model domains or for smaller regions within the model domain. These ground water budgets can be used to evaluate the impacts of pumping and estimate the magnitude of capture in the form of induced recharge from streams, as well as quantify storage changes within the system. The coupled analyses of ground water budget analysis and isotope sampling and analysis provide a means to confirm, refute, or modify conceptual models of ground water flow.
NASA Astrophysics Data System (ADS)
Son, Byeong-Kook; Lee, Seul-A.; Park, Mee-Sook
2015-04-01
Petroleum system modeling calculates and visualizes how and when hydrocarbons generate, migrate, and accumulate in a sedimentary basin. Therefore, it can be used effectively to predict the future prospects of oil and gas based on the understanding of the petroleum system in time and space. The petroleum system modeling was performed on the Sora Basin which is a small Cenozoic basin located offshore southern Korea, also including the offshore area of western Kyushu, Japan. Oil and gas shows were detected in two wells drilled in the basin, indicating that petroleum systems are present in the basin. Input parameters were selected from the well data as well as previous geological and geophysical studies for the 1-D model, from which thermal parameters such as heat flow and thermal maturity are also calculated and applied to 2-D model. The 2-D modeling was performed on an E-W seismic section across the basin from western margin in the Korea Block to eastern margin in Japanese Block. The PetroMod software was employed in the 2-D modeling, and stratigraphy, including lithology and organic content, was obtained from the wells and previous geological studies. 2-D modeling shows that hydrocarbons were expelled from the pod of the Eocene source rock in the Miocene time. The hydrocarbons migrate vertically along faults to the upper Oligocene sandstone formation, rather than the updip migrations along the sandstone bed, and hence form small-sized accumulations in the upper part of the sandstone formation. 3-D model was also performed based on depth maps of each formation in the Sora basin. Hydrocarbons are generated and expelled from the pod of the source rock of Eocene formation from 32Ma. In addition, the 3-D model shows that the hydrocarbon migrates northwestward and eastward in the carrier bed of sandstone. The petroleum models indicate that only a small amount of hydrocarbons are accumulated in the reservoir formation, probably due to small size of the basin and low degree
SINFAC - SYSTEMS IMPROVED NUMERICAL FLUIDS ANALYSIS CODE
NASA Technical Reports Server (NTRS)
Costello, F. A.
1994-01-01
The Systems Improved Numerical Fluids Analysis Code, SINFAC, consists of additional routines added to the April 1983 revision of SINDA, a general thermal analyzer program. The purpose of the additional routines is to allow for the modeling of active heat transfer loops. The modeler can simulate the steady-state and pseudo-transient operations of 16 different heat transfer loop components including radiators, evaporators, condensers, mechanical pumps, reservoirs and many types of valves and fittings. In addition, the program contains a property analysis routine that can be used to compute the thermodynamic properties of 20 different refrigerants. SINFAC can simulate the response to transient boundary conditions. SINFAC was first developed as a method for computing the steady-state performance of two phase systems. It was then modified using CNFRWD, SINDA's explicit time-integration scheme, to accommodate transient thermal models. However, SINFAC cannot simulate pressure drops due to time-dependent fluid acceleration, transient boil-out, or transient fill-up, except in the accumulator. SINFAC also requires the user to be familiar with SINDA. The solution procedure used by SINFAC is similar to that which an engineer would use to solve a system manually. The solution to a system requires the determination of all of the outlet conditions of each component such as the flow rate, pressure, and enthalpy. To obtain these values, the user first estimates the inlet conditions to the first component of the system, then computes the outlet conditions from the data supplied by the manufacturer of the first component. The user then estimates the temperature at the outlet of the third component and computes the corresponding flow resistance of the second component. With the flow resistance of the second component, the user computes the conditions down stream, namely the inlet conditions of the third. The computations follow for the rest of the system, back to the first component
Numerical likelihood analysis of cosmic ray anisotropies
Carlos Hojvat et al.
2003-07-02
A numerical likelihood approach to the determination of cosmic ray anisotropies is presented which offers many advantages over other approaches. It allows a wide range of statistically meaningful hypotheses to be compared even when full sky coverage is unavailable, can be readily extended in order to include measurement errors, and makes maximum unbiased use of all available information.
Numerical analysis of Swiss roll metamaterials.
Demetriadou, A; Pendry, J B
2009-08-12
A Swiss roll metamaterial is a resonant magnetic medium, with a negative magnetic permeability for a range of frequencies, due to its self-inductance and self-capacitance components. In this paper, we discuss the band structure, S-parameters and effective electromagnetic parameters of Swiss roll metamaterials, with both analytical and numerical results, which show an exceptional convergence.
Tularosa Basin Play Fairway Analysis: Methodology Flow Charts
Adam Brandt
2015-11-15
These images show the comprehensive methodology used for creation of a Play Fairway Analysis to explore the geothermal resource potential of the Tularosa Basin, New Mexico. The deterministic methodology was originated by the petroleum industry, but was custom-modified to function as a knowledge-based geothermal exploration tool. The stochastic PFA flow chart uses weights of evidence, and is data-driven.
Application of Sediment Backstripping Corrections for Basin Analysis Using Microcomputers.
ERIC Educational Resources Information Center
Wilkerson, Marlon Scott; Hsui, Albert Tong-Kwan
1989-01-01
Discussed is a program created to serve as an instructional tool for teaching basin analysis. Described is the use of the program for interpreting plots resulting from backstripping methods. Included in the discussion are implementation, applications and availability of the "Subside!" program. (CW)
Application of Sediment Backstripping Corrections for Basin Analysis Using Microcomputers.
ERIC Educational Resources Information Center
Wilkerson, Marlon Scott; Hsui, Albert Tong-Kwan
1989-01-01
Discussed is a program created to serve as an instructional tool for teaching basin analysis. Described is the use of the program for interpreting plots resulting from backstripping methods. Included in the discussion are implementation, applications and availability of the "Subside!" program. (CW)
NASA Astrophysics Data System (ADS)
Mingari, Leonardo A.; Collini, Estela A.; Folch, Arnau; Báez, Walter; Bustos, Emilce; Soledad Osores, María; Reckziegel, Florencia; Alexander, Peter; Viramonte, José G.
2017-06-01
On 13 June 2015, the London Volcanic Ash Advisory Centre (VAAC) warned the Buenos Aires VAAC about a possible volcanic eruption from the Nevados Ojos del Salado volcano (6879 m), located in the Andes mountain range on the border between Chile and Argentina. A volcanic ash cloud was detected by the SEVIRI instrument on board the Meteosat Second Generation (MSG) satellites from 14:00 UTC on 13 June. In this paper, we provide the first comprehensive description of this event through observations and numerical simulations. Our results support the hypothesis that the phenomenon was caused by wind remobilization of ancient pyroclastic deposits (ca. 4.5 ka Cerro Blanco eruption) from the Bolsón de Fiambalá (Fiambalá Basin) in northwestern Argentina. We have investigated the spatiotemporal distribution of aerosols and the emission process over complex terrain to gain insight into the key role played by the orography and the condition that triggered the long-range transport episode. Numerical simulations of windblown dust were performed using the ARW (Advanced Research WRF) core of the WRF (Weather Research and Forecasting) model (WRF-ARW) and FALL3D modeling system with meteorological fields downscaled to a spatial resolution of 2 km in order to resolve the complex orography of the area. Results indicate that favorable conditions to generate dust uplifting occurred in northern Fiambalá Basin, where orographic effects caused strong surface winds. According to short-range numerical simulations, dust particles were confined to near-ground layers around the emission areas. In contrast, dust aerosols were injected up to 5-6 km high in central and southern regions of the Fiambalá Basin, where intense ascending airflows are driven by horizontal convergence. Long-range transport numerical simulations were also performed to model the dust cloud spreading over northern Argentina. Results of simulated vertical particle column mass were compared with the MSG-SEVIRI retrieval
Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby
2006-02-28
The principal research effort for Year 3 of the project is basin modeling and petroleum system identification, comparative basin evaluation and resource assessment. In the first six (6) months of Year 3, the research focus is on basin modeling and petroleum system identification and the remainder of the year the emphasis is on the comparative basin evaluation and resource assessment. No major problems have been encountered to date, and the project is on schedule. The principal objectives of the project are to develop through basin analysis and modeling the concept that petroleum systems acting in a basin can be identified through basin modeling and to demonstrate that the information and analysis resulting from characterizing and modeling of these petroleum systems in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin can be used in providing a more reliable and advanced approach for targeting stratigraphic traps and specific reservoir facies within a geologic system and in providing a refined assessment of undiscovered and underdeveloped reservoirs and associated oil and gas resources.
Analysis of single ring infiltrometer test by direct numerical modeling
NASA Astrophysics Data System (ADS)
Réfloch, Aurore; Oxarango, Laurent; Rossier, Yvan; Gaudet, Jean Paul
2016-04-01
The well field of the Lyon metropolitan area provides drinking water to approximately 1,300,000 inhabitants. It is equipped with 12 infiltration basins. These basins have two main goals: sustaining the water table in times of peak demand for water, and preventing a possible contamination from the Rhône river by inverting groundwater flow direction. The water infiltration under the basins is thus crucial for the overall hydrogeologic behavior of the site. In order to characterize this phenomenon, a set of infiltrometer tests were performed to estimate the soil hydraulic properties. The soil is a coarse alluvial deposits. In order to deal with its sparse granulometric curve, a large single ring infiltrometer (1 meter in diameter) was used. A constant hydraulic head (=0.07 m) was imposed during the test. Two kinds of data are recorded: the amount of water infiltrated over time and the extension of the moisture stain around the ring. The main hydraulic properties are estimated using Richard's equation in a 2D axi-symmetric configuration. Simulations are performed using a finite element commercial software package (Comsol Multiphysics 5.1). According to simplified numerical models, an average homogeneous saturated permeability of the alluvial deposits is estimated at 5.0 10-6 m.s-1. However, such a simple model is not able to represent accurately the moisture stain at the soil surface. More complex models introduce anisotropy of permeability in the alluvium layer, with mono or bi-layer domain. In these cases, experimental and modeling results are consistent, both for the amount of water infiltrated over time and the extension of the moisture stain around the ring. The hydraulic anisotropy in the soil could be due to the stratified nature of alluvial deposits and to soil compaction during the construction of infiltration basins. Keywords: Single ring infiltrometer test, artificial aquifer recharge, numerical modeling.
A Numerical Model for Atomtronic Circuit Analysis
Chow, Weng W.; Straatsma, Cameron J. E.; Anderson, Dana Z.
2015-07-16
A model for studying atomtronic devices and circuits based on finite-temperature Bose-condensed gases is presented. The approach involves numerically solving equations of motion for atomic populations and coherences, derived using the Bose-Hubbard Hamiltonian and the Heisenberg picture. The resulting cluster expansion is truncated at a level giving balance between physics rigor and numerical demand mitigation. This approach allows parametric studies involving time scales that cover both the rapid population dynamics relevant to nonequilibrium state evolution, as well as the much longer time durations typical for reaching steady-state device operation. This model is demonstrated by studying the evolution of a Bose-condensed gas in the presence of atom injection and extraction in a double-well potential. In this configuration phase locking between condensates in each well of the potential is readily observed, and its influence on the evolution of the system is studied.
Numerical analysis of single and multiple jets
NASA Astrophysics Data System (ADS)
Boussoufi, Mustapha; Sabeur-Bendehina, Amina; Ouadha, Ahmed; Morsli, Souad; El Ganaoui, Mohammed
2017-05-01
The present study aims to use the concept of entropy generation in order to study numerically the flow and the interaction of multiple jets. Several configurations of a single jet surrounded by equidistant 3, 5, 7 and 9 circumferential jets have been studied. The turbulent incompressible Navier-Stokes equations have been solved numerically using the commercial computational fluid dynamics code Fluent. The standard k-ɛ model has been selected to assess the eddy viscosity. The domain has been reduced to a quarter of the geometry due to symmetry. Results for axial and radial velocities have been compared with experimental measurements from the literature. Furthermore, additional results involving entropy generation rate have been presented and discussed. Contribution to the topical issue "Materials for Energy harvesting, conversion and storage II (ICOME 2016)", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui
Numerical Analysis of the SCHOLAR Supersonic Combustor
NASA Technical Reports Server (NTRS)
Rodriguez, Carlos G.; Cutler, Andrew D.
2003-01-01
The SCHOLAR scramjet experiment is the subject of an ongoing numerical investigation. The facility nozzle and combustor were solved separate and sequentially, with the exit conditions of the former used as inlet conditions for the latter. A baseline configuration for the numerical model was compared with the available experimental data. It was found that ignition-delay was underpredicted and fuel-plume penetration overpredicted, while the pressure rise was close to experimental values. In addition, grid-convergence by means of grid-sequencing could not be established. The effects of the different turbulence parameters were quantified. It was found that it was not possible to simultaneously predict the three main parameters of this flow: pressure-rise, ignition-delay, and fuel-plume penetration.
NASA Astrophysics Data System (ADS)
Aulicino, Giuseppe; Cotroneo, Yuri; Ruiz, Simon; Sanchez Roman, Antonio; Pascual, Ananda; Fusco, Giannetta; Tintoré, Joaquin; Budillon, Giorgio
2017-04-01
The Algerian Basin is a key-place for the study of the general circulation of the Western Mediterranean Sea and its role in reaction to climate change. The presence of both fresh Atlantic waters and more saline resident Mediterranean ones characterizes the basin with an intense inflow/outflow regime and complex circulation patterns. Very energetic mesoscale structures, that evolve from meander of the Algerian Current to isolated cyclonic and anti-cyclonic eddies, dominate the area with marked repercussions on the biological activity. Despite their remarkable importance, this region and its variability are still poorly known and basin-wide high resolution knowledge of its mesoscale and sub-mesoscale features is still incomplete. The monitoring of such complex processes requires a synergic approach that involves integrated observing systems. In recent years, several studies proved the advantages of the combined use of autonomous underwater vehicles, such as gliders, with a new generation of satellite altimeters. In this context, we present the first results of a new integrated oceanographic observing system built up in the Algerian Basin during fall 2014 and 2015, aiming at advancing our knowledge on its main features. The study was realized through the analysis of glider high resolutions three-dimensional observations, collected along the Algerian BAsin Circulation Unmanned Survey (ABACUS) monitoring line, in synergy with co-located SARAL/AltiKa altimetric products and CMEMS numerical simulations. The achieved results confirm that glider derived dynamic height and SARAL/AltiKa absolute dynamic topography present similar patterns, with RMS of the differences ranging between 1.11 and 2.90 cm. Generally, the maximum discrepancies are located nearby the Balearic Islands and the Algerian Coast, but it is important to remark that the correlation coefficients seem to mostly depend on the synopticity between in situ and satellite measurements. Still, this study confirm that
Numerical Analysis of Robust Phase Estimation
NASA Astrophysics Data System (ADS)
Rudinger, Kenneth; Kimmel, Shelby
Robust phase estimation (RPE) is a new technique for estimating rotation angles and axes of single-qubit operations, steps necessary for developing useful quantum gates [arXiv:1502.02677]. As RPE only diagnoses a few parameters of a set of gate operations while at the same time achieving Heisenberg scaling, it requires relatively few resources compared to traditional tomographic procedures. In this talk, we present numerical simulations of RPE that show both Heisenberg scaling and robustness against state preparation and measurement errors, while also demonstrating numerical bounds on the procedure's efficacy. We additionally compare RPE to gate set tomography (GST), another Heisenberg-limited tomographic procedure. While GST provides a full gate set description, it is more resource-intensive than RPE, leading to potential tradeoffs between the procedures. We explore these tradeoffs and numerically establish criteria to guide experimentalists in deciding when to use RPE or GST to characterize their gate sets.Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.
Sophocleous, M.A.; Koelliker, J.K.; Govindaraju, R.S.; Birdie, T.; Ramireddygari, S.R.; Perkins, S.P.
1999-01-01
The objective of this article is to develop and implement a comprehensive computer model that is capable of simulating the surface-water, ground-water, and stream-aquifer interactions on a continuous basis for the Rattlesnake Creek basin in south-central Kansas. The model is to be used as a tool for evaluating long-term water-management strategies. The agriculturally-based watershed model SWAT and the ground-water model MODFLOW with stream-aquifer interaction routines, suitably modified, were linked into a comprehensive basin model known as SWATMOD. The hydrologic response unit concept was implemented to overcome the quasi-lumped nature of SWAT and represent the heterogeneity within each subbasin of the basin model. A graphical user-interface and a decision support system were also developed to evaluate scenarios involving manipulation of water fights and agricultural land uses on stream-aquifer system response. An extensive sensitivity analysis on model parameters was conducted, and model limitations and parameter uncertainties were emphasized. A combination of trial-and-error and inverse modeling techniques were employed to calibrate the model against multiple calibration targets of measured ground-water levels, streamflows, and reported irrigation amounts. The split-sample technique was employed for corroborating the calibrated model. The model was run for a 40 y historical simulation period, and a 40 y prediction period. A number of hypothetical management scenarios involving reductions and variations in withdrawal rates and patterns were simulated. The SWATMOD model was developed as a hydrologically rational low-flow model for analyzing, in a user-friendly manner, the conditions in the basin when there is a shortage of water.
NASA Astrophysics Data System (ADS)
Sophocleous, M. A.; Koelliker, J. K.; Govindaraju, R. S.; Birdie, T.; Ramireddygari, S. R.; Perkins, S. P.
1999-01-01
The objective of this article is to develop and implement a comprehensive computer model that is capable of simulating the surface-water, ground-water, and stream-aquifer interactions on a continuous basis for the Rattlesnake Creek basin in south-central Kansas. The model is to be used as a tool for evaluating long-term water-management strategies. The agriculturally-based watershed model SWAT and the ground-water model MODFLOW with stream-aquifer interaction routines, suitably modified, were linked into a comprehensive basin model known as SWATMOD. The hydrologic response unit concept was implemented to overcome the quasi-lumped nature of SWAT and represent the heterogeneity within each subbasin of the basin model. A graphical user-interface and a decision support system were also developed to evaluate scenarios involving manipulation of water rights and agricultural land uses on stream-aquifer system response. An extensive sensitivity analysis on model parameters was conducted, and model limitations and parameter uncertainties were emphasized. A combination of trial-and-error and inverse modeling techniques were employed to calibrate the model against multiple calibration targets of measured ground-water levels, streamflows, and reported irrigation amounts. The split-sample technique was employed for corroborating the calibrated model. The model was run for a 40 y historical simulation period, and a 40 y prediction period. A number of hypothetical management scenarios involving reductions and variations in withdrawal rates and patterns were simulated. The SWATMOD model was developed as a hydrologically rational low-flow model for analyzing, in a user-friendly manner, the conditions in the basin when there is a shortage of water.
Detrital Zircon Geochronology Applied to Basin Analysis
NASA Astrophysics Data System (ADS)
Gehrels, G. E.
2014-12-01
pathways (commonly involving episodes of recycling), characterizing source regions, establishing connections between drainage areas and offshore basins, and evaluating reservoir characteristics.
NASA Astrophysics Data System (ADS)
Sehrt, Manuel; Glasmacher, Ulrich A.
2014-05-01
The Tarfaya Basin is the northern part of the Tarfaya-Laâyoune-Dakhla Basin that extends over 1000 km along the western Saharan margin from the Mauritanian border to the Canary Islands in the north. The basin is bounded by the Mauritanide thrust belt and Precambrian Reguibat Arch in the SE-E and the Palaeozoic fold belt of the Anti-Atlas in the NE. A large amount of Mesozoic terrigenous sedimentary rocks are deposited in most of the basins along the continental margin of Morocco indicating a major episode of erosion occurred during the rift and early post-rift period in the Central Atlantic. In the Tarfaya-Laâyoune-Dakhla Basin, the Mesozoic to Cenozoic sedimentary cover reaches a thickness of up to 12 km. The presence of high surface elevations in the Anti-Atlas mountain belt (2700 m) indicates a potential source area for the surrounding basins, i.e. the Tarfaya Basin. The present study was focused on the thermal and inversion history of the Tarfaya Basin, the provenance of the Meso-Cenozoic sedimentary rocks of the basin and additionally on the thermal and exhumation history of the Western Anti-Atlas. In order to characterize the t-T history, apatite and zircon fission-track dating, apatite and zircon (U-Th-Sm)/He dating and furthermore 2-D modelling with 'HeFTy' software has been carried out at Precambrian rocks of the Western Anti-Atlas and Cretaceous to Neogene sedimentary rocks from the Tarfaya Basin. Thermochronological data and t-T path modelling indicate an inversion of the onshore Tarfaya Basin in the Palaeogene. The provenance analysis suggests an almost continuous sediment transport from the Anti-Atlas to the Tarfaya Basin and a simultaneous sediment input from the Reguibat Shield.
Basin analysis studies of lower Paleozoic rocks, Powder River basin, Wyoming and Montana
Macke, D.L.
1988-07-01
The lower Paleozoic (Cambrian through Mississippian) sedimentary rocks of the Powder River basin represent nearly half of Phanerozoic time, yet they remain virtually unexplored in the subsurface. Rocks of the same age in the Big Horn and Williston basins and in the Central Montana trough have produced much oil and gas, as have the overlying Pennsylvanian strata of the Powder River basin. A synthesis of published stratigraphic information, together with a regional analysis of sedimentary sequences, has been undertaken to evaluate the economic potential of the lower Paleozoic formations. The lack of an economic impetus to study these rocks has hampered the development of precise depositional models for these sequences. Furthermore, the depths of prospective beds, as well as long-standing misconceptions about the regional stratigraphy, have also served to restrain exploration. Stratigraphic studies have documented a succession of marine transgressions and regressions on the flanks of a highland in southeastern Wyoming. The highland persisted as a subdued geographic feature through most of early Paleozoic time, until it rose at the end of the Mississippian. Erosion during the Late Silurian and Devonian removed much of the depositional record in the area, but onlap can be demonstrated with relative certainty for Ordovician and Mississippian rocks. The repetition of sedimentologic features indicates persistent geologic controls in the region and suggests that these paleoenvironments might provide good targets for exploration.
NASA Astrophysics Data System (ADS)
Zanini, A.; Tanda, M.
2007-12-01
The groundwater in Italy plays an important role as drinking water; in fact it covers about the 30% of the national demand (70% in Northern Italy). The mineral water distribution in Italy is an important business with an increasing demand from abroad countries. The mineral water Companies have a great interest in order to increase the water extraction, but for the delicate and complex geology of the subsoil, where such very high quality waters are contained, a particular attention must be paid in order to avoid an excessive lowering of the groundwater reservoirs or great changes in the groundwater flow directions. A big water Company asked our University to set up a numerical model of the groundwater basin, in order to obtain a useful tool which allows to evaluate the strength of the aquifer and to design new extraction wells. The study area is located along Appennini Mountains and it covers a surface of about 18 km2; the topography ranges from 200 to 600 m a.s.l.. In ancient times only a spring with naturally sparkling water was known in the area, but at present the mineral water is extracted from deep pumping wells. The area is characterized by a very complex geology: the subsoil structure is described by a sequence of layers of silt-clay, marl-clay, travertine and alluvial deposit. Different groundwater layers are present and the one with best quality flows in the travertine layer; the natural flow rate seems to be not subjected to seasonal variations. The water age analysis revealed a very old water which means that the mineral aquifers are not directly connected with the meteoric recharge. The Geologists of the Company suggest that the water supply of the mineral aquifers comes from a carbonated unit located in the deep layers of the mountains bordering the spring area. The valley is crossed by a river that does not present connections to the mineral aquifers. Inside the area there are about 30 pumping wells that extract water at different depths. We built a 3
Numerical analysis of slender vortex motion
Zhou, H.
1996-02-01
Several numerical methods for slender vortex motion (the local induction equation, the Klein-Majda equation, and the Klein-Knio equation) are compared on the specific example of sideband instability of Kelvin waves on a vortex. Numerical experiments on this model problem indicate that all these methods yield qualitatively similar behavior, and this behavior is different from the behavior of a non-slender vortex with variable cross-section. It is found that the boundaries between stable, recurrent, and chaotic regimes in the parameter space of the model problem depend on the method used. The boundaries of these domains in the parameter space for the Klein-Majda equation and for the Klein-Knio equation are closely related to the core size. When the core size is large enough, the Klein-Majda equation always exhibits stable solutions for our model problem. Various conclusions are drawn; in particular, the behavior of turbulent vortices cannot be captured by these local approximations, and probably cannot be captured by any slender vortex model with constant vortex cross-section. Speculations about the differences between classical and superfluid hydrodynamics are also offered.
Heilweil, V.M.; Freethey, G.W.; Wilkowske, C.D.; Stolp, B.J.; Wilberg, D.E.
2000-01-01
Because rapid growth of communities in Washington and Iron Counties, Utah, is expected to cause an increase in the future demand for water resources, a hydrologic investigation was done to better understand ground-water resources within the central Virgin River basin. This study focused on two of the principal ground-water reservoirs within the basin: the upper Ash Creek basin ground-water system and the Navajo and Kayenta aquifer system.The ground-water system of the upper Ash Creek drainage basin consists of three aquifers: the uppermost Quaternary basin-fill aquifer, the Tertiary alluvial-fan aquifer, and the Tertiary Pine Valley monzonite aquifer. These aquifers are naturally bounded by the Hurricane Fault and by drainage divides. On the basis of measurements, estimates, and numerical simulations of reasonable values for all inflow and outflow components, total water moving through the upper Ash Creek drainage basin ground-water system is estimated to be about 14,000 acre-feet per year. Recharge to the upper Ash Creek drainage basin ground-water system is mostly from infiltration of precipitation and seepage from ephemeral and perennial streams. The primary source of discharge is assumed to be evapotranspiration; however, subsurface discharge near Ash Creek Reservoir also may be important.The character of two of the hydrologic boundaries of the upper Ash Creek drainage basin ground-water system is speculative. The eastern boundary provided by the Hurricane Fault is assumed to be a no-flow boundary, and a substantial part of the ground-water discharge from the system is assumed to be subsurface outflow beneath Ash Creek Reservoir along the southern boundary. However, these assumptions might be incorrect because alternative numerical simulations that used different boundary conditions also proved to be feasible. The hydrogeologic character of the aquifers is uncertain because of limited data. Differences in well yield indicate that there is considerable
Numerical Modelling of multi-stage basin inversion in the western Barents Shelf
NASA Astrophysics Data System (ADS)
Armaghan Faisal Miraj, Muhammad; Pascal, Christphe; Gabrielsen, Roy H.; Faleide, Jan Inge
2016-04-01
Numerical modeling of inversion induced by different regional tectonic forces from Late Triassic to Miocene is presented. Our goal is to predict strain and stress pattern evolution and to test the observed tectonic inversion events in the western Barents Sea. We used a finite-element numerical code, namely ANSYS™, to simulate stress and fault slip patterns and four 2-D thin plate modelling setups with different boundary conditions were constructed. We assumed four different regional events: Late Triassic to Early Jurassic E-W compression presumably connected to westward translation of Novaya Zemlya (Model 1), Late Cretaceous NE-SW directed far field stresses (Model 2), dextral megashear between Greenland and the Barents Sea Shelf in Early Eocene (Model 3) and NW-SE Atlantic ridge push from Miocene to present-day (Model 4). Model 1 results show a strike-slip regime along the central segment of the Thor Iversen Fault Complex and the Troms-Finnmark Fault Complex. Compressive regimes along the Måsøy and Hoop fault complexes favor development of inversion structures in the study area during Late Triassic to Early Jurassic. Simulated stress patterns in Model 2 suggest a clockwise stress rotation along the Bjørnøyrenna Fault Complex and the Ringvassøy - Loppa Fault Complex and pronounced stress deflections along the Asterias Fault Complex. These modeled stress deflections support tectonic inversion during Late Cretaceous-early Tertiary along the corresponding fault complexes. The results obtained in Model 3 suggest that the interior of the western Barents Sea was not severely influenced by Early Eocene North Atlantic opening/shearing. Stress rotations are modelled along the Senja Fracture Zone and Hornsund Fault Complex which separate the study area into two different rheological domains. The results suggest that Early Eocene sea floor spreading caused stress partitioning along the Senja Fracture Zone. The observed inversion structures may be related to local
Numerical Sensitivity Analysis of a Composite Impact Absorber
NASA Astrophysics Data System (ADS)
Caputo, F.; Lamanna, G.; Scarano, D.; Soprano, A.
2008-08-01
This work deals with a numerical investigation on the energy absorbing capability of structural composite components. There are several difficulties associated with the numerical simulation of a composite impact-absorber, such as high geometrical non-linearities, boundary contact conditions, failure criteria, material behaviour; all those aspects make the calibration of numerical models and the evaluation of their sensitivity to the governing geometrical, physical and numerical parameters one of the main objectives of whatever numerical investigation. The last aspect is a very important one for designers in order to make the application of the model to real cases robust from both a physical and a numerical point of view. At first, on the basis of experimental data from literature, a preliminary calibration of the numerical model of a composite impact absorber and then a sensitivity analysis to the variation of the main geometrical and material parameters have been developed, by using explicit finite element algorithms implemented in the Ls-Dyna code.
Manufacturing in space: Fluid dynamics numerical analysis
NASA Technical Reports Server (NTRS)
Robertson, S. J.; Nicholson, L. A.; Spradley, L. W.
1982-01-01
Numerical computations were performed for natural convection in circular enclosures under various conditions of acceleration. It was found that subcritical acceleration vectors applied in the direction of the temperature gradient will lead to an eventual state of rest regardless of the initial state of motion. Supercritical acceleration vectors will lead to the same steady state condition of motion regardless of the initial state of motion. Convection velocities were computed for acceleration vectors at various angles of the initial temperature gradient. The results for Rayleigh numbers of 1000 or less were found to closely follow Weinbaum's first order theory. Higher Rayleigh number results were shown to depart significantly from the first order theory. Supercritical behavior was confirmed for Rayleigh numbers greater than the known supercritical value of 9216. Response times were determined to provide an indication of the time required to change states of motion for the various cases considered.
Numerical Analysis of Magnetic Sail Spacecraft
Sasaki, Daisuke; Yamakawa, Hiroshi; Usui, Hideyuki; Funaki, Ikkoh; Kojima, Hirotsugu
2008-12-31
To capture the kinetic energy of the solar wind by creating a large magnetosphere around the spacecraft, magneto-plasma sail injects a plasma jet into a strong magnetic field produced by an electromagnet onboard the spacecraft. The aim of this paper is to investigate the effect of the IMF (interplanetary magnetic field) on the magnetosphere of magneto-plasma sail. First, using an axi-symmetric two-dimensional MHD code, we numerically confirm the magnetic field inflation, and the formation of a magnetosphere by the interaction between the solar wind and the magnetic field. The expansion of an artificial magnetosphere by the plasma injection is then simulated, and we show that the magnetosphere is formed by the interaction between the solar wind and the magnetic field expanded by the plasma jet from the spacecraft. This simulation indicates the size of the artificial magnetosphere becomes smaller when applying the IMF.
Procedures for numerical analysis of circadian rhythms
REFINETTI, ROBERTO; LISSEN, GERMAINE CORNÉ; HALBERG, FRANZ
2010-01-01
This article reviews various procedures used in the analysis of circadian rhythms at the populational, organismal, cellular and molecular levels. The procedures range from visual inspection of time plots and actograms to several mathematical methods of time series analysis. Computational steps are described in some detail, and additional bibliographic resources and computer programs are listed. PMID:23710111
The Analysis, Numerical Simulation, and Diagnosis of Extratropical Weather Systems
1999-09-30
respectively, and iv ) the numerical simulation and observational validation of high-spatial resolution (~10 km) numerical predictions. APPROACH My approach...satellite and targeted dropwindsonde observations; in collaboration with Xiaolie Zou (Fla. State Univ.), Chris Velden (Univ. Wisc ./CIMMS), and Arlin...Univ. Wisc .), and Arlin Krueger (NASA/GSFC). Analysis and numerical simulation of the fine-scale structure of upper-level jet streams from high- spatial
Research in applied mathematics, numerical analysis, and computer science
NASA Technical Reports Server (NTRS)
1984-01-01
Research conducted at the Institute for Computer Applications in Science and Engineering (ICASE) in applied mathematics, numerical analysis, and computer science is summarized and abstracts of published reports are presented. The major categories of the ICASE research program are: (1) numerical methods, with particular emphasis on the development and analysis of basic numerical algorithms; (2) control and parameter identification; (3) computational problems in engineering and the physical sciences, particularly fluid dynamics, acoustics, and structural analysis; and (4) computer systems and software, especially vector and parallel computers.
Witkowski, W.R.; Eldred, M.S.; Harding, D.C.
1994-09-01
The use of state-of-the-art numerical analysis tools to determine the optimal design of a radioactive material (RAM) transportation container is investigated. The design of a RAM package`s components involves a complex coupling of structural, thermal, and radioactive shielding analyses. The final design must adhere to very strict design constraints. The current technique used by cask designers is uncoupled and involves designing each component separately with respect to its driving constraint. With the use of numerical optimization schemes, the complex couplings can be considered directly, and the performance of the integrated package can be maximized with respect to the analysis conditions. This can lead to more efficient package designs. Thermal and structural accident conditions are analyzed in the shape optimization of a simplified cask design. In this paper, details of the integration of numerical analysis tools, development of a process model, nonsmoothness difficulties with the optimization of the cask, and preliminary results are discussed.
Numerical analysis of ellipsometric critical adsorption data
NASA Astrophysics Data System (ADS)
Smith, Dan S. P.; Law, Bruce M.; Smock, Martin; Landau, David P.
1997-01-01
A recent study [Dan S. P. Smith and Bruce M. Law, Phys. Rev. E 54, 2727 (1996)] presented measurements of the ellipsometric coefficient at the Brewster angle ρ-bar on the liquid-vapor surface of four different binary liquid mixtures in the vicinity of their liquid-liquid critical point and analyzed the data analytically for large reduced temperatures t. In the current report we analyze this (ρ-bar,t) data numerically over the entire range of t. Theoretical universal surface scaling functions P+/-(x) from a Monte Carlo (MC) simulation [M. Smock, H. W. Diehl, and D. P. Landau, Ber. Bunsenges. Phys. Chem. 98, 486 (1994)] and a renormalization-group (RG) calculation [H. W. Diehl and M. Smock, Phys. Rev. B 47, 5841 (1993); 48, 6470(E) (1993)] are used in the numerical integration of Maxwell's equations to provide theoretical (ρ-bar,t) curves that can be compared directly with the experimental data. While both the MC and RG curves are in qualitative agreement with the experimental data, the agreement is generally found to be better for the MC curves. However, systematic discrepancies are found in the quantitative comparison between the MC and experimental (ρ-bar,t) curves, and it is determined that these discrepancies are too large to be due to experimental error. Finally, it is demonstrated that ρ-bar can be rescaled to produce an approximately universal ellipsometric curve as a function of the single variable ξ+/-/λ, where ξ is the correlation length and λ is the wavelength of light. The position of the maximum of this curve in the one-phase region, (ξ+/λ)peak, is approximately a universal number. It is determined that (ξ+/λ)peak is dependent primarily on the ratio c+/P∞,+, where P+(x)≅c+x-Β/ν for x<<1 and P+(x)≅P∞,+e-x for x>>:1. This enables the experimental estimate of c+/P∞,+=0.90+/-0.24, which is significantly large compared to the MC and RG values of 0.577 and 0.442, respectively.
Carlson, Carl S.; Mondazzi, Remo A.; Bjerklie, David M.; Brown, Craig J.
2010-01-01
A study of the groundwater and stream-aquifer interaction in the Pootatuck River Basin, Newtown, Connecticut, was conducted to analyze the effect of production wells on the groundwater levels and streamflow in the Pootatuck River as part of a cooperative program between the U.S. Geological Survey and Newtown, Connecticut. This study will help address concerns about the increasing competition for water for human uses and protection of aquatic habitat. The groundwater-flow model developed in the study was designed for use as a tool to assist planners in assessing the effects of potential future development, which will change the amount and distribution of recharge available to the groundwater system. Several different techniques were used to investigate the interconnection between the stream and the aquifer. Temperature, groundwater levels, stream stage, and stable-isotope data collected during aquifer tests at the principal production wells in the Pootatuck River Basin, as well as groundwater-flow simulations of the system, indicate that more than half of the water pumped from the wells comes from the Pootatuck River. This finding potentially has a large effect on approaches for protecting the water quality of the pumped water. Increases in the amount of impervious surface from future development will reduce and redistribute recharge to the groundwater system. The simulation of future development scenarios showed a decrease in the simulated base flow in the main stem of the Pootatuck River and in all of the 26 simulated subbasins, with some of the subbasins showing a decrease of more than 20 percent when new development had 85 percent impervious area. The groundwater-flow model and particle tracking were used to determine areas that contribute recharge to the five production wells available for use in the Pootatuck River Basin. These areas included narrow portions of the aquifer that extended beyond the immediate upgradient areas, probably because of deeper
NASA Astrophysics Data System (ADS)
Yamato, Philippe; Castelltort, Sébastien; Willett, Sean
2010-05-01
The last two decades have been marked by a large amount of studies on the relative influences of climate and tectonics on landscape evolution. Coevally, considerable advances have been achieved in numerical modelling of landscape evolution. These have been particularly useful in testing hypotheses and scenarios of the potential controls and feedbacks between climate, tectonics and landscape evolution. However, our current knowledge of the physical processes of erosion in nature remains incomplete. Indeed, although the predictions of landscape evolution models are often insightful, they are also sometimes overlooked due to their lack of physical basis. In parallel with current field and experimental investigations on erosion processes, one way to tackle this problem is to compare simulated and natural landscapes. Then, this allows us to know how can one assess whether a simulated landscape is realistic in a long-standing problem in geomorphology. The scaling between stream length and upstream drainage area, a relation known as Hack's law (Hack, 1957) provides a constrain on the geometry of natural landscapes. It is however notoriously difficult to use this law to assess the goodness of a landscape evolution model since it must be regarded over a logarithmic range of scales (stream orders), which is usually not possible in landscape evolution models because of their resolution. The convergence angle, a measure of a basin's elongation (Castelltort et al., 2009) is a similar metrics of drainage basin shape. It is controlled by the slope and roughness of the undissected surface on which a new basin develops. This relation arises from analytical predictions of water flow over simple topography and is supported by data on median to large-scale natural networks. In the present study we investigate the influence of slope and surface roughness on the shape of river basins using the CASCADE code (Braun and Sambridge, 1997). Results show that the rules used to route water in
Dongarra, J. . Dept. of Computer Science Oak Ridge National Lab., TN ); Rosener, B. . Dept. of Computer Science)
1991-12-01
This report describes a facility called NA-NET created to allow numerical analysts (na) an easy method of communicating with one another. The main advantage of the NA-NET is uniformity of addressing. All mail is addressed to the Internet host na-net.ornl.gov'' at Oak Ridge National Laboratory. Hence, members of the NA-NET do not need to remember complicated addresses or even where a member is currently located. As long as moving members change their e-mail address in the NA-NET everything works smoothly. The NA-NET system is currently located at Oak Ridge National Laboratory. It is running on the same machine that serves netlib. Netlib is a separate facility that distributes mathematical software via electronic mail. For more information on netlib consult, or send the one-line message send index'' to netlib{at}ornl.gov. The following report describes the current NA-NET system from both a user's perspective and from an implementation perspective. Currently, there are over 2100 members in the NA-NET. An average of 110 mail messages pass through this facility daily.
Dongarra, J. |; Rosener, B.
1991-12-01
This report describes a facility called NA-NET created to allow numerical analysts (na) an easy method of communicating with one another. The main advantage of the NA-NET is uniformity of addressing. All mail is addressed to the Internet host ``na-net.ornl.gov`` at Oak Ridge National Laboratory. Hence, members of the NA-NET do not need to remember complicated addresses or even where a member is currently located. As long as moving members change their e-mail address in the NA-NET everything works smoothly. The NA-NET system is currently located at Oak Ridge National Laboratory. It is running on the same machine that serves netlib. Netlib is a separate facility that distributes mathematical software via electronic mail. For more information on netlib consult, or send the one-line message ``send index`` to netlib{at}ornl.gov. The following report describes the current NA-NET system from both a user`s perspective and from an implementation perspective. Currently, there are over 2100 members in the NA-NET. An average of 110 mail messages pass through this facility daily.
Numerical analysis for finite Fresnel transform
NASA Astrophysics Data System (ADS)
Aoyagi, Tomohiro; Ohtsubo, Kouichi; Aoyagi, Nobuo
2016-10-01
The Fresnel transform is a bounded, linear, additive, and unitary operator in Hilbert space and is applied to many applications. In this study, a sampling theorem for a Fresnel transform pair in polar coordinate systems is derived. According to the sampling theorem, any function in the complex plane can be expressed by taking the products of the values of a function and sampling function systems. Sampling function systems are constituted by Bessel functions and their zeros. By computer simulations, we consider the application of the sampling theorem to the problem of approximating a function to demonstrate its validity. Our approximating function is a circularly symmetric function which is defined in the complex plane. Counting the number of sampling points requires the calculation of the zeros of Bessel functions, which are calculated by an approximation formula and numerical tables. Therefore, our sampling points are nonuniform. The number of sampling points, the normalized mean square error between the original function and its approximation function and phases are calculated and the relationship between them is revealed.
Basin Acoustic Seamount Scattering Experiment (BASSEX) Data Analysis and Modeling
2007-09-30
Basin Acoustic Seamount Scattering Experiment (BASSEX) Data Analysis and Modeling Kevin D. Heaney Ocean Acoustical Services and...propagation regimes are the focus of this work: 1.) seamount scattering, 2.) open ocean propagation and 3.) downslope propagation and subsequent deep...water propagation. The long-term goal is understand scattering off of seamounts and island slopes and to develop algorithms for modeling the acoustic
Basin Acoustic Seamount Scattering Experiment (BASSEX) Data Analysis and Modeling
2005-08-30
shadow zone produced by seamounts with vertical extensions into the sound channel axis have been made. Measurements of 3D propagation have been made off...Basin Acoustic Seamount Scattering Experiment (BASSEX) Data Analysis and Modeling Kevin D. Heaney Ocean Acoustical Services and...propagation regimes are the focus of this work: 1.) seamount scattering, 2.) open ocean propagation and 3.) downslope propagation in a
Numerical Analysis Of Interlaminar-Fracture Toughness
NASA Technical Reports Server (NTRS)
Chamis, C. C.; Murthy, P. L. N.
1988-01-01
Finite-element analysis applied in conjunction with strain-energy and micromechanical concepts. Computational procedure involves local, local-crack-closure, and/or the "unique" local-crack-closure method developed at NASA Lewis Research Center, for mathematical modeling of ENF and MMF. Methods based on three-dimensional finite-element analysis in conjunction with concept of strain-energy-release rate and with micromechanics of composite materials. Assists in interpretation of ENF and MMF fracture tests performed to obtain fracture-toughness parameters, by enabling evaluation of states of stress likely to induce interlaminar fractures.
An analysis of the carbon balance of the Arctic Basin
Mcguire, David; Hayes, Daniel J; Kicklighter, David W.; Manizza, Manfredi; Zhuang, Qianlai; Chen, Min; Follows, Michael J; Gurney, Kevin; Mcclelland, James W; Melillo, Jerry; Peterson, Bruce; Prinn, Ronald
2010-01-01
This study used several model-based tools to analyse the dynamics of the Arctic Basin between 1997 and 2006 as a linked system of land-ocean-atmosphere C exchange. The analysis estimates that terrestrial areas of the Arctic Basin lost 62.9 Tg C yr 1 and that the Arctic Ocean gained 94.1 Tg C yr 1. Arctic lands and oceans were a net CO2 sink of 108.9 Tg C yr 1, which is within the range of uncertainty in estimates from atmospheric inversions. Although both lands and oceans of the Arctic were estimated to be CO2 sinks, the land sink diminished in strength because of increased fire disturbance compared to previous decades, while the ocean sink increased in strength because of increased biological pump activity associated with reduced sea ice cover. Terrestrial areas of the Arctic were a net source of 41.5 Tg CH4 yr 1 that increased by 0.6 Tg CH4 yr 1 during the decade of analysis, a magnitude that is comparable with an atmospheric inversion of CH4. Because the radiative forcing of the estimated CH4 emissions is much greater than the CO2 sink, the analysis suggests that the Arctic Basin is a substantial net source of green house gas forcing to the climate system.
Hydrological regime analysis of the Selenge River basin, Mongolia
NASA Astrophysics Data System (ADS)
Ma, X.; Yasunari, T.; Ohata, T.; Natsagdorj, L.; Davaa, G.; Oyunbaatar, D.
2003-10-01
Arid and semi-arid regions are very vulnerable to environmental changes. Climate change studies indicate that the environment in such areas will steadily deteriorate with global warming; inland lakes will shrink and desert areas will expand. Mongolia is a landlocked country in north-central Asia that contains a unique ecological system consisting of taiga, steppe, and desert from north to south. The Selenge River basin (280 000 km2) in northern Mongolia is a semi-arid region underlain by permafrost, between latitudes 46 and 52Â°N, and longitudes 96 and 109Â°E. The issue of sustainable development of the basin is very important owing to its limited natural resources, including fresh water, forest, and rangeland. To examine the water cycle processes in the basin, a hydrological analysis was carried out using a simple scheme for the interaction between the land surface and atmosphere (big-leaf model) coupled to a hydrological model for the period 1988-92 to estimate the hydrological regime of the basin. Annual precipitation in this period averaged 298 mm, ranging from 212 to 352 mm at a 1 Â° × 1 Â° resolution based on data from 10 gauges, and the estimated annual evapotranspiration averaged 241 mm, ranging between 153 and 300 mm. This indicates that evapotranspiration accounts for the overwhelming majority of the annual precipitation, averaging 81% and ranging between 64 and 96%. The annual potential evapotranspiration in the basin averaged 2009 mm; the ratio of evapotranspiration (actual to potential evapotranspiration) was 0Â·12 and the wetness index (annual precipitation to potential evapotranspiration) was 0Â·15. Copyright
Synoptic climatological analysis of persistent cold air pools over the Carpathian Basin
NASA Astrophysics Data System (ADS)
Szabóné André, Karolina; Bartholy, Judit; Pongrácz, Rita
2016-04-01
A persistent cold air pool (PCAP) is a winter-time, anticyclone-related weather event over a relatively large basin. During this time the air is colder near the surface than aloft. This inversion near the surface can last even for weeks. As the cold air cools down, relative humidity increases and fog forms. The entire life cycle of a PCAP depends on the large scale circulation pattern. PCAP usually appears when an anticyclone builds up after a cold front passed over the examined basin, and it is usually destructed by a coming strong cold front of another midlatitude cyclone. Moreover, the intensity of the anticyclone affects the intensity of the PCAP. PCAP may result in different hazards for the population: (1) Temperature inversion in the surface layers together with weak wind may lead to severe air pollution causing health problems for many people, especially, elderly and children. (2) The fog and/or smog during chilly weather conditions often results in freezing rain. Both fog and freezing rain can distract transportation and electricity supply. Unfortunately, the numerical weather prediction models have difficulties to predict PCAP formation and destruction. One of the reasons is that PCAP is not defined objectively with a simple formula, which could be easily applied to the numerical output data. However, according to some recommendations from the synoptic literature, the shallow convective potential energy (SCPE) can be used to mathematically describe PCAP. In this study, we used the ERA-Interim reanalysis datasets to examine this very specific weather event (i.e., PCAP) over the Carpathian Basin. The connection between the mean sea level pressure and some PCAP measures (e.g., SCPE, energy deficit, etc.) is evaluated. For instance, we used logistic regression to identify PCAP periods over the Carpathian Basin. Then, further statistical analysis includes the evaluation of the length and intensity of these PCAP periods.
Numerical analysis of the orthogonal descent method
Shokov, V.A.; Shchepakin, M.B.
1994-11-01
The author of the orthogonal descent method has been testing it since 1977. The results of these tests have only strengthened the need for further analysis and development of orthogonal descent algorithms for various classes of convex programming problems. Systematic testing of orthogonal descent algorithms and comparison of test results with other nondifferentiable optimization methods was conducted at TsEMI RAN in 1991-1992 using the results.
NASA Astrophysics Data System (ADS)
Stanev, Emil Vassilev; Grashorn, Sebastian; Zhang, Yinglong Joseph
2017-08-01
In this paper, we use the unstructured grid model SCHISM to simulate the thermohydrodynamics in a chain of baroclinic, interconnected basins. The model shows a good skill in simulating the horizontal circulation and vertical profiles of temperature, salinity, and currents. The magnitude and phases of the seasonal changes of circulation are consistent with earlier observations. Among the mesoscale and subbasin-scale circulation features that are realistically simulated are the anticyclonic coastal eddies, the Sebastopol and Batumi eddies, the Marmara Sea outflow around the southern coast of the Limnos Island, and the pathway of the cold water originating from the shelf. The superiority of the simulations compared to earlier numerical studies is demonstrated with the example of model capabilities to resolve the strait dynamics, gravity currents originating from the straits, high-salinity bottom layer on the shallow shelf, as well as the multiple intrusions from the Bosporus Strait down to 700 m depth. The warm temperature intrusions from the strait produce the warm water mass in the intermediate layers of the Black Sea. One novel result is that the seasonal intensification of circulation affects the interbasin exchange, thus allowing us to formulate the concept of circulation-controlled interbasin exchange. To the best of our knowledge, the present numerical simulations, for the first time, suggest that the sea level in the interior part of the Black Sea can be lower than the sea level in the Marmara Sea and even in some parts of the Aegean Sea. The comparison with observations shows that the timings and magnitude of exchange flows are also realistically simulated, along with the blocking events. The short-term variability of the strait transports is largely controlled by the anomalies of wind. The simulations demonstrate the crucial role of the narrow and shallow strait of Bosporus in separating the two pairs of basins: Aegean-Marmara Seas from one side and Azov
Ernest A. Mancini
2004-02-05
The principal research effort for Year 1 of the project is data compilation and the determination of the tectonic and depositional histories of the North Louisiana Salt Basin. In the first three (3) to six (6) months of Year 1, the research focus is on data compilation and the remainder of the year the emphasis is on the tectonic and depositional histories of the basin. No major problems have been encountered to date, and the project is on schedule. The principal objectives of the project are to develop through basin analysis and modeling the concept that petroleum systems acting in a basin can be identified through basin modeling and to demonstrate that the information and analysis resulting from characterizing and modeling of these petroleum systems in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin can be used in providing a more reliable and advanced approach for targeting stratigraphic traps and specific reservoir facies within a geologic system and in providing a refined assessment of undiscovered and underdeveloped reservoirs and associated oil and gas resources.
NASA Astrophysics Data System (ADS)
Tallman, A. A.; Richards, K. E.; Stringer, A. C.; Weaver, J.; Daus, A.; Robinson, J. C.
2008-12-01
Geomatrix conducted a hydrogeologic assessment of the Inarajan and Tinaga River basins in southern Guam to develop a conceptual understanding of groundwater flow and occurrence in support of design, construction, and operation of a regional municipal landfill. Few previous hydrologic studies have focused on southern Guam, and thus this study provided the first detailed comprehensive assessment of groundwater and surface water conditions in the area. Data collected from an extensive field program, along with previous investigations were used to develop a hydrogeologic conceptual model describing regional and site geology, hydrostratigraphy, and groundwater and surface water flow. A three-dimensional numerical groundwater flow model of the system was developed using MODFLOW-SURFACT. The model was used to test various alternative conceptualizations and to provide a tool to evaluate landfill design and potential impacts to water resources from construction and operation of the landfill. The nature of the local watershed systems allowed for design of a basin-scale model. Historic USGS daily discharge measurements on the Inarajan and Tinaga Rivers coupled with historic precipitation records facilitated the basin scale approach. The model was calibrated to both steady state and transient conditions allowing for simulation of groundwater flow under a variety of conditions. Following calibration, predictive simulations were conducted to assess various aspects of landfill construction. The primary finding of the predictive assessments was that elimination of areal recharge resulting from construction of the landfill will cause a dramatic lowering of the water table in the weathered and fractured pyroclastic units that underlie the site. In addition, construction of the landfill will likely result in some reduction in stream base flow. Discharge of storm water runoff from the landfill into adjacent wetlands will mitigate some of the predicted impacts to base flow and
Numerical bifurcation analysis of immunological models with time delays
NASA Astrophysics Data System (ADS)
Luzyanina, Tatyana; Roose, Dirk; Bocharov, Gennady
2005-12-01
In recent years, a large number of mathematical models that are described by delay differential equations (DDEs) have appeared in the life sciences. To analyze the models' dynamics, numerical methods are necessary, since analytical studies can only give limited results. In turn, the availability of efficient numerical methods and software packages encourages the use of time delays in mathematical modelling, which may lead to more realistic models. We outline recently developed numerical methods for bifurcation analysis of DDEs and illustrate the use of these methods in the analysis of a mathematical model of human hepatitis B virus infection.
Numerical analysis on pump turbine runaway points
NASA Astrophysics Data System (ADS)
Guo, L.; Liu, J. T.; Wang, L. Q.; Jiao, L.; Li, Z. F.
2012-11-01
To research the character of pump turbine runaway points with different guide vane opening, a hydraulic model was established based on a pumped storage power station. The RNG k-ε model and SMPLEC algorithms was used to simulate the internal flow fields. The result of the simulation was compared with the test data and good correspondence was got between experimental data and CFD result. Based on this model, internal flow analysis was carried out. The result show that when the pump turbine ran at the runway speed, lots of vortexes appeared in the flow passage of the runner. These vortexes could always be observed even if the guide vane opening changes. That is an important way of energy loss in the runaway condition. Pressure on two sides of the runner blades were almost the same. So the runner power is very low. High speed induced large centrifugal force and the small guide vane opening gave the water velocity a large tangential component, then an obvious water ring could be observed between the runner blades and guide vanes in small guide vane opening condition. That ring disappeared when the opening bigger than 20°. These conclusions can provide a theory basis for the analysis and simulation of the pump turbine runaway points.
Numerical Uncertainty Quantification for Radiation Analysis Tools
NASA Technical Reports Server (NTRS)
Anderson, Brooke; Blattnig, Steve; Clowdsley, Martha
2007-01-01
Recently a new emphasis has been placed on engineering applications of space radiation analyses and thus a systematic effort of Verification, Validation and Uncertainty Quantification (VV&UQ) of the tools commonly used for radiation analysis for vehicle design and mission planning has begun. There are two sources of uncertainty in geometric discretization addressed in this paper that need to be quantified in order to understand the total uncertainty in estimating space radiation exposures. One source of uncertainty is in ray tracing, as the number of rays increase the associated uncertainty decreases, but the computational expense increases. Thus, a cost benefit analysis optimizing computational time versus uncertainty is needed and is addressed in this paper. The second source of uncertainty results from the interpolation over the dose vs. depth curves that is needed to determine the radiation exposure. The question, then, is what is the number of thicknesses that is needed to get an accurate result. So convergence testing is performed to quantify the uncertainty associated with interpolating over different shield thickness spatial grids.
Numerical analysis of soil-structure interaction
NASA Astrophysics Data System (ADS)
Vanlangen, Harry
1991-05-01
A study to improve some existing procedures for the finite element analysis of soil deformation and collapse is presented. Special attention is paid to problems of soil structure interaction. Emphasis is put on the behavior of soil rather than on that of structures. This seems to be justifiable if static interaction of stiff structures and soft soil is considered. In such a case nonlinear response will exclusively stem from soil deformation. In addition, the quality of the results depends to a high extent on the proper modeling of soil flow along structures and not on the modeling of the structure itself. An exception is made when geotextile reinforcement is considered. In that case the structural element, i.e., the geotextile, is highly flexible. The equation of continuum equilibrium, which serves as a starting point for the finite element formulation of large deformation elastoplasticity, is discussed with special attention being paid to the interpretation of some objective stress rate tensors. The solution of nonlinear finite element equations is addressed. Soil deformation in the prefailure range is discussed. Large deformation effect in the analysis of soil deformation is touched on.
Sampling and Analysis Plan for K Basins Debris
WESTCOTT, J.L.
2000-06-21
This Sampling and Analysis Plan presents the rationale and strategy for sampling and analysis activities to support removal of debris from the K-East and K-West Basins located in the 100K Area at the Hanford Site. This project is focused on characterization to support waste designation for disposal of waste at the Environmental Restoration Disposal Facility (ERDF). This material has previously been dispositioned at the Hanford Low-Level Burial Grounds or Central Waste Complex. The structures that house the basins are classified as radioactive material areas. Therefore, all materials removed from the buildings are presumed to be radioactively contaminated. Because most of the materials that will be addressed under this plan will be removed from the basins, and because of the cost associated with screening materials for release, it is anticipated that all debris will be managed as low-level waste. Materials will be surveyed, however, to estimate radionuclide content for disposal and to determine that the debris is not contaminated with levels of transuranic radionuclides that would designate the debris as transuranic waste.
Hurricane Debby - Analysis and numerical forecasts using VAS soundings
NASA Technical Reports Server (NTRS)
Le Marshall, J. F.; Smith, W. L.; Callan, G. M.
1984-01-01
The utility of VISSR Atmospheric Sounder (VAS) temperature and moisture soundings in defining the storm and its surroundings at subsynoptic scales has been examined using a numerical analysis and prognosis system. In particular, VAS temperature and moisture soundings and cloud and water vapor motion winds have been used in numerical analysis for three time periods. It is shown that the VAS temperature and moisture data which specify temperature and moisture well in cloud free regions are complemented by cloud and water vapor wind data which provide horizontal gradient information for the cloudy areas. The loss of analysis integrity due to the reduction of VAS data density in the cloudy regions associated with synoptic activity is ameliorated by using cloud and water vapor motion winds. The improvement in numerical forecasts resulting from the addition of these data to the numerical data base is also recorded.
Numerical analysis of human dental occlusal contact
NASA Astrophysics Data System (ADS)
Bastos, F. S.; Las Casas, E. B.; Godoy, G. C. D.; Meireles, A. B.
2010-06-01
The purpose of this study was to obtain real contact areas, forces, and pressures acting on human dental enamel as a function of the nominal pressure during dental occlusal contact. The described development consisted of three steps: characterization of the surface roughness by 3D contact profilometry test, finite element analysis of micro responses for each pair of main asperities in contact, and homogenization of macro responses using an assumed probability density function. The inelastic deformation of enamel was considered, adjusting the stress-strain relationship of sound enamel to that obtained from instrumented indentation tests conducted with spherical tip. A mechanical part of the static friction coefficient was estimated as the ratio between tangential and normal components of the overall resistive force, resulting in μd = 0.057. Less than 1% of contact pairs reached the yield stress of enamel, indicating that the occlusal contact is essentially elastic. The micro-models indicated an average hardness of 6.25GPa, and the homogenized result for macroscopic interface was around 9GPa. Further refinements of the methodology and verification using experimental data can provide a better understanding of processes related to contact, friction and wear of human tooth enamel.
NASCRIN - NUMERICAL ANALYSIS OF SCRAMJET INLET
NASA Technical Reports Server (NTRS)
Kumar, A.
1994-01-01
The NASCRIN program was developed for analyzing two-dimensional flow fields in supersonic combustion ramjet (scramjet) inlets. NASCRIN solves the two-dimensional Euler or Navier-Stokes equations in conservative form by an unsplit, explicit, two-step finite-difference method. A more recent explicit-implicit, two-step scheme has also been incorporated in the code for viscous flow analysis. An algebraic, two-layer eddy-viscosity model is used for the turbulent flow calculations. NASCRIN can analyze both inviscid and viscous flows with no struts, one strut, or multiple struts embedded in the flow field. NASCRIN can be used in a quasi-three-dimensional sense for some scramjet inlets under certain simplifying assumptions. Although developed for supersonic internal flow, NASCRIN may be adapted to a variety of other flow problems. In particular, it should be readily adaptable to subsonic inflow with supersonic outflow, supersonic inflow with subsonic outflow, or fully subsonic flow. The NASCRIN program is available for batch execution on the CDC CYBER 203. The vectorized FORTRAN version was developed in 1983. NASCRIN has a central memory requirement of approximately 300K words for a grid size of about 3,000 points.
NASCRIN - NUMERICAL ANALYSIS OF SCRAMJET INLET
NASA Technical Reports Server (NTRS)
Kumar, A.
1994-01-01
The NASCRIN program was developed for analyzing two-dimensional flow fields in supersonic combustion ramjet (scramjet) inlets. NASCRIN solves the two-dimensional Euler or Navier-Stokes equations in conservative form by an unsplit, explicit, two-step finite-difference method. A more recent explicit-implicit, two-step scheme has also been incorporated in the code for viscous flow analysis. An algebraic, two-layer eddy-viscosity model is used for the turbulent flow calculations. NASCRIN can analyze both inviscid and viscous flows with no struts, one strut, or multiple struts embedded in the flow field. NASCRIN can be used in a quasi-three-dimensional sense for some scramjet inlets under certain simplifying assumptions. Although developed for supersonic internal flow, NASCRIN may be adapted to a variety of other flow problems. In particular, it should be readily adaptable to subsonic inflow with supersonic outflow, supersonic inflow with subsonic outflow, or fully subsonic flow. The NASCRIN program is available for batch execution on the CDC CYBER 203. The vectorized FORTRAN version was developed in 1983. NASCRIN has a central memory requirement of approximately 300K words for a grid size of about 3,000 points.
Combustion irreversibilities: Numerical simulation and analysis
NASA Astrophysics Data System (ADS)
Silva, Valter; Rouboa, Abel
2012-08-01
An exergy analysis was performed considering the combustion of methane and agro-industrial residues produced in Portugal (forest residues and vines pruning). Regarding that the irreversibilities of a thermodynamic process are path dependent, the combustion process was considering as resulting from different hypothetical paths each one characterized by four main sub-processes: reactant mixing, fuel oxidation, internal thermal energy exchange (heat transfer), and product mixing. The exergetic efficiency was computed using a zero dimensional model developed by using a Visual Basic home code. It was concluded that the exergy losses were mainly due to the internal thermal energy exchange sub-process. The exergy losses from this sub-process are higher when the reactants are preheated up to the ignition temperature without previous fuel oxidation. On the other hand, the global exergy destruction can be minored increasing the pressure, the reactants temperature and the oxygen content on the oxidant stream. This methodology allows the identification of the phenomena and processes that have larger exergy losses, the understanding of why these losses occur and how the exergy changes with the parameters associated to each system which is crucial to implement the syngas combustion from biomass products as a competitive technology.
Regional Slip Tendency Analysis of the Great Basin Region
Faulds, James E.
2013-09-30
are shown on Figure 3. For faults within the Great Basin proper, we applied a normal faulting stress regime, where the vertical stress (sv) is larger than the maximum horizontal stress (shmax), which is larger than the minimum horizontal stress (sv>shmax>shmin). Based on visual inspection of the limited stress magnitude data in the Great Basin, we used magnitudes such that shmin/shmax = .527 and shmin/sv= .46. These values are consistent with stress magnitude data at both Dixie Valley (Hickman et al., 2000) and Yucca Mountain (Stock et al., 1985). For faults within the Walker Lane/Eastern California Shear Zone, we applied a strike‐slip faulting stress, where shmax > sv > shmin. Upon visual inspection of limited stress magnitude data from the Walker Lane and Eastern California Shear zone, we chose values such that SHmin/SHmax = .46 and Shmin/Sv= .527 representative of the region. Results: The results of our slip and dilation tendency analysis are shown in Figures 4 (dilation tendency), 5 (slip tendency) and 6 (slip tendency + dilation tendency). Shmin varies from northwest to east‐west trending throughout much of the Great Basin. As such, north‐ to northeast‐striking faults have the highest tendency to slip and to dilate, depending on the local trend of shmin. These results provide a first order filter on faults and fault systems in the Great Basin, affording focusing of local‐scale exploration efforts for blind or hidden geothermal resources.
Analysis of water level variations in Brazilian basins using GRACE
NASA Astrophysics Data System (ADS)
Matos, A.; Blitzkow, D.; Almeida, F.; Costa, S.; Campos, I.; Barbosa, A.
2012-01-01
A comparison between daily
NASA Astrophysics Data System (ADS)
Pfunt, Helena; Houben, Georg; Himmelsbach, Thomas
2016-09-01
Gas production from shale formations by hydraulic fracturing has raised concerns about the effects on the quality of fresh groundwater. The migration of injected fracking fluids towards the surface was investigated in the North German Basin, based on the known standard lithology. This included cases with natural preferential pathways such as permeable fault zones and fracture networks. Conservative assumptions were applied in the simulation of flow and mass transport triggered by a high pressure boundary of up to 50 MPa excess pressure. The results show no significant fluid migration for a case with undisturbed cap rocks and a maximum of 41 m vertical transport within a permeable fault zone during the pressurization. Open fractures, if present, strongly control the flow field and migration; here vertical transport of fracking fluids reaches up to 200 m during hydraulic fracturing simulation. Long-term transport of the injected water was simulated for 300 years. The fracking fluid rises vertically within the fault zone up to 485 m due to buoyancy. Progressively, it is transported horizontally into sandstone layers, following the natural groundwater flow direction. In the long-term, the injected fluids are diluted to minor concentrations. Despite the presence of permeable pathways, the injected fracking fluids in the reported model did not reach near-surface aquifers, either during the hydraulic fracturing or in the long term. Therefore, the probability of impacts on shallow groundwater by the rise of fracking fluids from a deep shale-gas formation through the geological underground to the surface is small.
Hamming, R W
1965-04-23
I hope I have shown not that mathematicians are incompetent or wrong, but why I believe that their interests, tastes, and objectives are frequently different from those of practicing numerical analysts, and why activity in numerical analysis should be evaluated by its own standards and not by those of pure mathematics. I hope I have also shown you that much of the "art form" of mathematics consists of delicate, "noise-free" results, while many areas of applied mathematics, especially numerical analysis, are dominated by noise. Again, in computing the process is fundamental, and rigorous mathematical proofs are often meaningless in computing situations. Finally, in numerical analysis, as in engineering, choosing the right model is more important than choosing the model with the elegant mathematics.
A hydrologic analysis for the infiltration basins planned on Jeju Island, Korea
NASA Astrophysics Data System (ADS)
Lee, S.; Kang, T.; Lee, J.; Kang, S.
2010-12-01
Urban development is a cause of expansion of impervious area. It reduces infiltration of rain water and may increase runoff volume from storms. Infiltration basins can be a method to receive storm water and to let the water move into the soil. The contents of the study include a hydrologic analysis on a site and an evaluation of the capacity of infiltration basins planned on the site. Most region of Jeju Island, Korea is highly pervious. Three infiltration basins were designed on the area of the Jeju English Education City. To evaluate adequacy of the capacities of the infiltration basins, infiltration rates were measured and storm water runoff was simulated. Infiltration rates on the surface of the reserved land for infiltration basins were measured by a standard double ring infiltrometer or a small infiltrometer. A FORTRAN version of SWMM was modified to incorporate the infiltration basin and the basic equations of the infiltration basin are same as those of the infiltration trench used in MIDUSS. The code modified was used to simulate storm runoff from watersheds, infiltration from the infiltration basins, and reservoir routing of the infiltration basins. The saturated hydraulic conductivities on the reserved sites were measured by 0.0068, 0.0038, and 0.00017 cm/sec. The return period of the design rainfall is fifty years. The following results were obtained from a hydrologic analysis on the watersheds and the infiltration basins to be built. The two infiltration basins with higher infiltration rates have adequate capacities to infiltrate the total water inflow to the basins. Some water, however releases from the other infiltration basin and the capacity of the basin is not sufficient to infiltrate the total runoff after the land use change. A channel is needed in which the water released from the less pervious basin flows. The hydrologic analysis method of the study can be used for capacity evaluation of future infiltration basins on highly pervious areas in
NASA Astrophysics Data System (ADS)
Lipsey, Lindsay; van Wees, Jan-Diederik; Pluymaekers, Maarten; Cloetingh, Sierd
2015-04-01
Thermal anomalies in deep sedimentary settings are largely controlled by fluid circulation within permeable zones. Convection is of particular interest in geothermal exploration, as it creates areas with anomalously high temperatures at shallow depths. Recent work on the temperature distribution in the Dutch subsurface revealed a thermal anomaly at the Luttelgeest-01 (LTG-01) at 4-5 km depth, which could be explained by thermal convection. Temperature measurements show a shift to higher temperatures at depths greater than 4000 m, corresponding the Dinantian carbonates. In order for convective heat transport to explain the anomaly, there must also be sufficient permeability. Rayleigh number calculations show that convection may be possible within the Dinantian carbonate layer, depending on its thickness, permeability and geothermal gradient. For example, an average permeability of 60 mD permits convection in a 600 m aquifer, given a geothermal gradient of 31°C/km. If the permeability is reduced to 20 mD, convection can only occur where the thickness of the aquifer is greater than 900 m. Interestingly, numerical simulations were able to come within 5-10 mD of the theoretical minimum permeability values calculated for each scenario. 3D numerical simulations provide insight on possible flow and thermal structures within the fractured carbonate interval, as well as illustrate the role of permeability on the timing of convection onset, convection cell structure development and the resulting temperature patterns. The development and number of convection cells is very much a time dependent process. Many cells may develop in the beginning of simulations, but they seem to gradually converge until steady state is reached. The shape of convective upwellings varies from roughly circular or hexagonal to more elongated upwellings and downwellings. Furthermore, the geometric aspects of the carbonate platform itself likely control the shape and location of upwellings, as well as
NASA Astrophysics Data System (ADS)
Ishitsuka, Y.; Yoshimura, K.
2016-12-01
Floods have a potential to be a major source of economic or human damage caused by natural disasters. Flood prediction systems were developed all over the world and to treat the uncertainty of the prediction ensemble simulation is commonly adopted. In this study, ensemble flood prediction system using global scale land surface and hydrodynamic model was developed. The system requests surface atmospheric forcing and Land Surface Model, MATSIRO, calculates runoff. Those generated runoff is inputted to hydrodynamic model CaMa-Flood to calculate discharge and flood inundation. CaMa-Flood can simulate flood area and its fraction by introducing floodplain connected to river channel. Forecast leadtime was set 39hours according to forcing data. For the case study, the flood occurred at Kinu river basin, Japan in 2015 was hindcasted. In a 1761 km² Kinu river basin, 3-days accumulated average rainfall was 384mm and over 4000 people was left in the inundated area. Available ensemble numerical weather prediction data at that time was inputted to the system in a resolution of 0.05 degrees and 1hour time step. As a result, the system predicted the flood occurrence by 45% and 84% at 23 and 11 hours before the water level exceeded the evacuation threshold, respectively. Those prediction lead time may provide the chance for early preparation for the floods such as levee reinforcement or evacuation. Adding to the discharge, flood area predictability was also analyzed. Although those models were applied for Japan region, this system can be applied easily to other region or even global scale. The areal flood prediction in meso to global scale would be useful for detecting hot zones or vulnerable areas over each region.
Mancini, Ernest A.
2003-02-06
The project objectives are improving access to information for the Mississippi Interior Salt Basin by inventorying data files and records of the major information repositories in the region, making these inventories easily accessible in electronic format, increasing the amount of information available on domestic sedimentary basins through a comprehensive analysis of the Mississippi Interior Salt Basin, and enhancing the understanding of the petroleum systems operating in the Mississippi Interior Salt Basin.
Tularosa Basin Play Fairway Analysis: Partial Basin and Range Heat and Zones of Critical Stress Maps
Adam Brandt
2015-11-15
Interpolated maps of heat flow, temperature gradient, and quartz geothermometers are included as TIF files. Zones of critical stress map is also included as a TIF file. The zones are given a 5km diameter buffer. The study area is only a part of the Basin and Range, but it does includes the Tularosa Basin.
Drought Analysis in the Tuz Lake Basin, Central Anatolia, Turkey
NASA Astrophysics Data System (ADS)
Ustaoglu, Beyza; Akın, Burcu
2017-04-01
The research area, Tuz Lake Basin is located in Central Anatolia Region in Turkey. The drought is observed in this area with the result of the meteorological data analysis, satellite imagery and field research. The aim of this study is to determine temporal and spatial characterists of the drought, frequency and extreme droughtness possibilities, drought period, amplitude of the drought and its severity which is observed in Tuz Lake within the context of climate change process effects in Turkey, by using Standart Precipitation Index (SPI) Palmer Drought Harshness Index, De Martonne and Erinç Method. Since the indexes which are used in the study have different parameters, not only meteorological results but also agricultural and hydrological drought results can be inferred. For this purpose, measurements of 12 meteorological stations in the basin between the years 1975-2015 will be studied applying the aforementioned methods in MATLAB. SRTM satellite images used in the study is provided by American Geological Survey (USGS). The findings from satellite imagery and meteorological data integrated into Geographic Information Systems Software ArcMap 10.1, then the effects of the drought to the Tuz Lake were analyzed. The findings of the analysis will be interpreted with the support of the field studies.
Classification and analysis of candidate impact crater-hosted closed-basin lakes on Mars
NASA Astrophysics Data System (ADS)
Goudge, Timothy A.; Aureli, Kelsey L.; Head, James W.; Fassett, Caleb I.; Mustard, John F.
2015-11-01
We present a new catalog of 205 candidate closed-basin lakes contained within impact craters across the surface of Mars. These basins have an inlet valley that incises the crater rim and flows into the basin but no visible outlet valley, and are considered candidate closed-basin lakes; the presence of a valley flowing into a basin does not necessitate the formation of a standing body of water. The major geomorphic distinction within our catalog of candidate paleolakes is the length of the inlet valley(s), with two major classes - basins with long (>20 km) inlet valleys (30 basins), and basins with short (<20 km) inlet valleys (175 basins). We identify 55 basins that contain sedimentary fan deposits at the mouths of their inlet valleys, of which nine are fed by long inlet valleys and 46 are fed by short inlet valleys. Analysis of the mineralogy of these fan deposits suggests that they are primarily composed of detrital material. Additionally, we find no evidence for widespread evaporite deposit formation within our catalog of candidate closed-basin lakes, which we conclude is indicative of a general transience for any lakes that did form within these basins. Morphometric characteristics for our catalog indicate that as an upper limit, these basins represent a volume of water equivalent to a ∼1.2 m global equivalent layer (GEL) of water spread evenly across the martian surface; this is a small fraction of the modern water ice reservoir on Mars. Our catalog offers a broader context within which results from the Mars Science Laboratory Curiosity rover can be interpreted, as Gale crater is a candidate closed-basin lake contained within our catalog. Gale is also one of 12 closed-basin lakes fed by both long and short inlet valleys, and so in situ analyses by Curiosity can shed light on the relative importance of these two types of inlets for any lacustrine activity within the basin.
Numerical analysis of eccentric orifice plate using ANSYS Fluent software
NASA Astrophysics Data System (ADS)
Zahariea, D.
2016-11-01
In this paper the eccentric orifice plate is qualitative analysed as compared with the classical concentric orifice plate from the point of view of sedimentation tendency of solid particles in the fluid whose flow rate is measured. For this purpose, the numerical streamlines pattern will be compared for both orifice plates. The numerical analysis has been performed using ANSYS Fluent software. The methodology of CFD analysis is presented: creating the 3D solid model, fluid domain extraction, meshing, boundary condition, turbulence model, solving algorithm, convergence criterion, results and validation. Analysing the numerical streamlines, for the concentric orifice plate can be clearly observed two circumferential regions of separated flows, upstream and downstream of the orifice plate. The bottom part of these regions are the place where the solid particles could sediment. On the other hand, for the eccentric orifice plate, the streamlines pattern suggest that no sedimentation will occur because at the bottom area of the pipe there are no separated flows.
A general numerical model for wave rotor analysis
NASA Technical Reports Server (NTRS)
Paxson, Daniel W.
1992-01-01
Wave rotors represent one of the promising technologies for achieving very high core temperatures and pressures in future gas turbine engines. Their operation depends upon unsteady gas dynamics and as such, their analysis is quite difficult. This report describes a numerical model which has been developed to perform such an analysis. Following a brief introduction, a summary of the wave rotor concept is given. The governing equations are then presented, along with a summary of the assumptions used to obtain them. Next, the numerical integration technique is described. This is an explicit finite volume technique based on the method of Roe. The discussion then focuses on the implementation of appropriate boundary conditions. Following this, some results are presented which first compare the numerical approximation to the governing differential equations and then compare the overall model to an actual wave rotor experiment. Finally, some concluding remarks are presented concerning the limitations of the simplifying assumptions and areas where the model may be improved.
A general numerical model for wave rotor analysis
NASA Astrophysics Data System (ADS)
Paxson, Daniel W.
1992-07-01
Wave rotors represent one of the promising technologies for achieving very high core temperatures and pressures in future gas turbine engines. Their operation depends upon unsteady gas dynamics and as such, their analysis is quite difficult. This report describes a numerical model which has been developed to perform such an analysis. Following a brief introduction, a summary of the wave rotor concept is given. The governing equations are then presented, along with a summary of the assumptions used to obtain them. Next, the numerical integration technique is described. This is an explicit finite volume technique based on the method of Roe. The discussion then focuses on the implementation of appropriate boundary conditions. Following this, some results are presented which first compare the numerical approximation to the governing differential equations and then compare the overall model to an actual wave rotor experiment. Finally, some concluding remarks are presented concerning the limitations of the simplifying assumptions and areas where the model may be improved.
Dupree, Jean A.; Crowfoot, Richard M.
2012-01-01
The drainage basin is a fundamental hydrologic entity used for studies of surface-water resources and during planning of water-related projects. Numeric drainage areas published by the U.S. Geological Survey water science centers in Annual Water Data Reports and on the National Water Information Systems (NWIS) Web site are still primarily derived from hard-copy sources and by manual delineation of polygonal basin areas on paper topographic map sheets. To expedite numeric drainage area determinations, the Colorado Water Science Center developed a digital database structure and a delineation methodology based on the hydrologic unit boundaries in the National Watershed Boundary Dataset. This report describes the digital database architecture and delineation methodology and also presents the results of a comparison of the numeric drainage areas derived using this digital methodology with those derived using traditional, non-digital methods. (Please see report for full Abstract)
Numerical Simulation of Several Tectonic Tsunami Sources at the Caribbean Basin
NASA Astrophysics Data System (ADS)
Chacon-Barrantes, S. E.; Lopez, A. M.; Macias, J.; Zamora, N.; Moore, C. W.; Llorente Isidro, M.
2016-12-01
The Tsunami Hazard Assessment Working Group (WG2) of the Intergovernmental Coordination Group for the Tsunami and Other Coastal Hazards Early Warning System for the Caribbean and Adjacent Regions (ICG/CARIBE-EWS), has been tasked to identify tsunami sources for the Caribbean region and evaluate their effects along Caribbean coasts. A list of tectonic sources was developed and presented at the Fall 2015 AGU meeting and the WG2 is currently working on a list of non-tectonic sources. In addition, three Experts Meetings have already been held in 2016 to define worst-case, most credible scenarios for southern Hispaniola and Central America. The WG2 has been tasked to simulate these scenarios to provide an estimate of the resulting effects on coastal areas within the Caribbean. In this study we simulated tsunamis with two leading numerical models (NEOWAVE and Tsunami-HySEA) to compare results among them and report on the consequences for the Caribbean region if a tectonically-induced tsunami occurs in any of these postulated sources. The considered sources are located offshore Central America, at the North Panamá Deformed Belt (NPDB), at the South Caribbean Deformed Belt (SCDB) and around La Hispaniola Island. Results obtained in this study are critical to develop a catalog of scenarios that can be used in future CaribeWave exercises, as well as their usage for ICG/CARIBE-EWS member states as input to model tsunami inundation for their coastal locations. Data from inundation parameters are an additional step to produce tsunami evacuation maps, and develop plans and procedures to increase tsunami awareness and preparedness within the Caribbean.
NASA Astrophysics Data System (ADS)
Singh, A.; Palombi, D.; Huff, G. F.
2014-12-01
A regional scale study of groundwater flow dynamics was undertaken in the Western Canada Sedimentary Basin (WCSB), comprising parts of Alberta, Saskatchewan and British Columbia. The objective of the study is to investigate basin-scale hydrogeology in WCSB and to establish boundary conditions for future local-scale groundwater management models. Earlier work in the Alberta basin has acknowledged the fact that in addition to topography controlled conditions, a substantial part of the basin exhibits sub-hydrostatic regimes. The basin-scale model (approx. 420,000 km2) includes Upper Cretaceous aquifers to Recent age sediments which collectively attain maximum thicknesses of >2600 m. Regional aquifer units considered for the numerical model are Quaternary sediments, and the sedimentary rocks of the Paskapoo, Scollard, Horseshoe Canyon formations and the Belly River Group. Regional aquitards delineated include the Battle and Bear Paw formations. The study area is bound to the west by the Brazeau-Waptiti thrust belt and to the south by the Canada-USA international border. The boundary to the north and east is delineated by the maximum extent of the Wapiti and Belly River groups and Judith River Formation. USGS MODFLOW was implemented for numerical simulation. The steady state numerical model was calibrated using a Response Surface based (Radial Basis Functions) optimization method. The calibration targets (~2000) were comprised of drill stem tests for deeper units and static water levels for shallower units. Petrophysical analyses of cores averaged K values from analyses of aquifer test results,and literature values were used to provide initial values and calibration ranges for hydraulic properties. Results indicate predominance of topography driven, local- to intermediate-scale flow systems in all hydrostratigraphic units with recharge of these units occurring in the foothills of the Rocky Mountains. The Battle aquitard, where present, acts to retard regional flow
Investigating Convergence Patterns for Numerical Methods Using Data Analysis
ERIC Educational Resources Information Center
Gordon, Sheldon P.
2013-01-01
The article investigates the patterns that arise in the convergence of numerical methods, particularly those in the errors involved in successive iterations, using data analysis and curve fitting methods. In particular, the results obtained are used to convey a deeper level of understanding of the concepts of linear, quadratic, and cubic…
Numerical analysis of strongly nonlinear extensional vibrations in elastic rods.
Vanhille, Christian; Campos-Pozuelo, Cleofé
2007-01-01
In the framework of transduction, nondestructive testing, and nonlinear acoustic characterization, this article presents the analysis of strongly nonlinear vibrations by means of an original numerical algorithm. In acoustic and transducer applications in extreme working conditions, such as the ones induced by the generation of high-power ultrasound, the analysis of nonlinear ultrasonic vibrations is fundamental. Also, the excitation and analysis of nonlinear vibrations is an emergent technique in nonlinear characterization for damage detection. A third-order evolution equation is derived and numerically solved for extensional waves in isotropic dissipative media. A nine-constant theory of elasticity for isotropic solids is constructed, and the nonlinearity parameters corresponding to extensional waves are proposed. The nonlinear differential equation is solved by using a new numerical algorithm working in the time domain. The finite-difference numerical method proposed is implicit and only requires the solution of a linear set of equations at each time step. The model allows the analysis of strongly nonlinear, one-dimensional vibrations and can be used for prediction as well as characterization. Vibration waveforms are calculated at different points, and results are compared for different excitation levels and boundary conditions. Amplitude distributions along the rod axis for every harmonic component also are evaluated. Special attention is given to the study of high-amplitude damping of vibrations by means of several simulations. Simulations are performed for amplitudes ranging from linear to nonlinear and weak shock.
Investigating Convergence Patterns for Numerical Methods Using Data Analysis
ERIC Educational Resources Information Center
Gordon, Sheldon P.
2013-01-01
The article investigates the patterns that arise in the convergence of numerical methods, particularly those in the errors involved in successive iterations, using data analysis and curve fitting methods. In particular, the results obtained are used to convey a deeper level of understanding of the concepts of linear, quadratic, and cubic…
Scilab and Maxima Environment: Towards Free Software in Numerical Analysis
ERIC Educational Resources Information Center
Mora, Angel; Galan, Jose Luis; Aguilera, Gabriel; Fernandez, Alvaro; Merida, Enrique; Rodriguez, Pedro
2010-01-01
In this work we will present the ScilabUMA environment we have developed as an alternative to Matlab. This environment connects Scilab (for numerical analysis) and Maxima (for symbolic computations). Furthermore, the developed interface is, in our opinion at least, as powerful as the interface of Matlab. (Contains 3 figures.)
Scilab and Maxima Environment: Towards Free Software in Numerical Analysis
ERIC Educational Resources Information Center
Mora, Angel; Galan, Jose Luis; Aguilera, Gabriel; Fernandez, Alvaro; Merida, Enrique; Rodriguez, Pedro
2010-01-01
In this work we will present the ScilabUMA environment we have developed as an alternative to Matlab. This environment connects Scilab (for numerical analysis) and Maxima (for symbolic computations). Furthermore, the developed interface is, in our opinion at least, as powerful as the interface of Matlab. (Contains 3 figures.)
MI-Sim: A MATLAB package for the numerical analysis of microbial ecological interactions.
Wade, Matthew J; Oakley, Jordan; Harbisher, Sophie; Parker, Nicholas G; Dolfing, Jan
2017-01-01
Food-webs and other classes of ecological network motifs, are a means of describing feeding relationships between consumers and producers in an ecosystem. They have application across scales where they differ only in the underlying characteristics of the organisms and substrates describing the system. Mathematical modelling, using mechanistic approaches to describe the dynamic behaviour and properties of the system through sets of ordinary differential equations, has been used extensively in ecology. Models allow simulation of the dynamics of the various motifs and their numerical analysis provides a greater understanding of the interplay between the system components and their intrinsic properties. We have developed the MI-Sim software for use with MATLAB to allow a rigorous and rapid numerical analysis of several common ecological motifs. MI-Sim contains a series of the most commonly used motifs such as cooperation, competition and predation. It does not require detailed knowledge of mathematical analytical techniques and is offered as a single graphical user interface containing all input and output options. The tools available in the current version of MI-Sim include model simulation, steady-state existence and stability analysis, and basin of attraction analysis. The software includes seven ecological interaction motifs and seven growth function models. Unlike other system analysis tools, MI-Sim is designed as a simple and user-friendly tool specific to ecological population type models, allowing for rapid assessment of their dynamical and behavioural properties.
MI-Sim: A MATLAB package for the numerical analysis of microbial ecological interactions
Oakley, Jordan; Harbisher, Sophie; Parker, Nicholas G.; Dolfing, Jan
2017-01-01
Food-webs and other classes of ecological network motifs, are a means of describing feeding relationships between consumers and producers in an ecosystem. They have application across scales where they differ only in the underlying characteristics of the organisms and substrates describing the system. Mathematical modelling, using mechanistic approaches to describe the dynamic behaviour and properties of the system through sets of ordinary differential equations, has been used extensively in ecology. Models allow simulation of the dynamics of the various motifs and their numerical analysis provides a greater understanding of the interplay between the system components and their intrinsic properties. We have developed the MI-Sim software for use with MATLAB to allow a rigorous and rapid numerical analysis of several common ecological motifs. MI-Sim contains a series of the most commonly used motifs such as cooperation, competition and predation. It does not require detailed knowledge of mathematical analytical techniques and is offered as a single graphical user interface containing all input and output options. The tools available in the current version of MI-Sim include model simulation, steady-state existence and stability analysis, and basin of attraction analysis. The software includes seven ecological interaction motifs and seven growth function models. Unlike other system analysis tools, MI-Sim is designed as a simple and user-friendly tool specific to ecological population type models, allowing for rapid assessment of their dynamical and behavioural properties. PMID:28273164
NASA Astrophysics Data System (ADS)
Kim, J.; Moridis, G. J.
2012-12-01
Gas hydrate reservoirs are currently considered as one of the clean future energy resources. Gas hydrates, which mainly consist of methane, are solid crystalline compounds in which gas molecules are trapped within the lattice of ice crystals. From their thermodynamic characteristics, they are typically found in the oceanic sediments or permafrost regions. One of the main concerns related to gas production from the hydrate deposits is geomechanical instability. When the hydrates, which support part of the stress in the formations, are dissociated or formed, the stress and strain fields are significantly changed. In particular, the oceanic hydrate sediments are highly affected by geomechanics, because of huge overburden. In this study, we investigate geomechanical responses from a marine hydrate accumulation at the Ulleung basin in the Korean East Sea, by numerical simulation, when gas is produced by depressurization. Depressurization is widely used for gas production from the hydrate deposits, dissociating the hydrates. We employ two-way coupling between flow and geomechanics, proposed by Kim et al. (SPE Journal 2012 17(2):485-501), in order to model variations in porosity and permeability more rigorously. From the numerical results, the geomechanical situation appears challenging, as significant subsidence (exceeding 3.5 m near the sea floor and 1.5 m at the top of the hydrate deposit) is estimated to occur along a large part of the wellbore, and geomechanical failure within the 20m-thick system is possible early in the production process. However, there is still significant uncertainty in geomechanical data, because the data are incomplete. Further simulations based on the experimental and field data will be required.
Numerical Analysis of Modal Instability Onset in Fiber Amplifiers
2014-03-11
ABSTRACT 16. SECURITY CLASSIFICATION OF: Numerical analysis of the onset of modal instability in fiber amplifiers is presented. Specifically calculations...analysis of modal instability onset in fiber amplifiers The views, opinions and/or findings contained in this report are those of the author(s) and...linear effects, thermal effects, power scaling, fiber lasers, modal instability, stimulated thermal Rayleigh scattering REPORT DOCUMENTATION PAGE 11
Numerical simulation of unidirectional irregular nonlinear waves in the basin of intermediate depth
NASA Astrophysics Data System (ADS)
Slunyaev, Alexey; Sergeeva, Anna; Didenkulova, Ira
2016-04-01
waves over intermediate-depth waves, we show that in the situation of very rough sea, the extreme waves possess noticeable front-rear asymmetry in all considered cases. In the situation of modulationaly stable waves, kph ≈ 1 < 1.36, the asymmetry is equally pronounced as in the deeper water situations. Thus the Benjamin - Feir instability seems to be irrelevant for this peculiarity of extreme wave shapes. The results of numerical simulations are discussed in view of available in-situ measurements at shallow regions of the Baltic Sea. [1] A. Sergeeva, A. Slunyaev, Rogue waves, rogue events and extreme wave kinematics in spatio-temporal fields of simulated sea states. Nat. Hazards Earth Syst. Sci. 13, 1759-1771 (2013).
Numerical analysis of ossicular chain lesion of human ear
NASA Astrophysics Data System (ADS)
Liu, Yingxi; Li, Sheng; Sun, Xiuzhen
2009-04-01
Lesion of ossicular chain is a common ear disease impairing the sense of hearing. A comprehensive numerical model of human ear can provide better understanding of sound transmission. In this study, we propose a three-dimensional finite element model of human ear that incorporates the canal, tympanic membrane, ossicular bones, middle ear suspensory ligaments/muscles, middle ear cavity and inner ear fluid. Numerical analysis is conducted and employed to predict the effects of middle ear cavity, malleus handle defect, hypoplasia of the long process of incus, and stapedial crus defect on sound transmission. The present finite element model is shown to be reasonable in predicting the ossicular mechanics of human ear.
Formulation of numerical procedures for dynamic analysis of spinning structures
NASA Technical Reports Server (NTRS)
Gupta, K. K.
1986-01-01
The paper presents the descriptions of recently developed numerical algorithms that prove to be useful for the solution of the free vibration problem of spinning structures. First, a generalized procedure for the computation of nodal centrifugal forces in a finite element owing to any specified spin rate is derived in detail. This is followed by a description of an improved eigenproblem solution procedure that proves to be economical for the free vibration analysis of spinning structures. Numerical results are also presented which indicate the efficacy of the currently developed procedures.
Using Paleocurrents for Basin-Scale Hydrological Analysis: an Example from the Amazon Basin
NASA Astrophysics Data System (ADS)
Wheatley, A.; Rigsby, C. A.; Silva, C. G.; Salenbien, W.; Baker, P. A.
2016-12-01
Paleocurrent analysis is a long-established technique of great value to stratigraphy and paleoenvironmental reconstruction. In the case of the Amazon - the largest river system in the world - a continental-scale drainage reversal (from a Pacific-draining system to the extant Atlantic-draining system) has been suggested, typically hypothesized during or after the Miocene, with paleocurrent observations playing a significant role in attempts to constrain the timing and nature of such a reversal (Horbe et al., 2013). Yet, while a well-developed statistical framework exists for outcrop-level interpretation of paleocurrents, questions remain with regard to extending paleocurrent observations to draw continent-scale conclusions. Using a stream model of the Amazon River system derived from 1 arcsecond SRTM data, we present results of a Monte Carlo analysis to simulate the preservation, discovery and measurement of paleocurrent indicators in the rock record. We consider variable degrees of prior knowledge of the system and variable ability to distinguish relative stream orders to assess the effect of these factors on data confidence. We show that, where the location of the most major rivers can be well-constrained, at least 17 independent observations are required for the random sample to resemble the overall drainage pattern 95% of the time if determining between two potential directions; at least 23 observations are required to determine between four potential directions. If no prior knowledge of the basin's configuration is known, 82 and 71 observations are required, respectively, to reach a 95% confidence. Disregarding smaller streams does not consistently decrease the evidence required to reach 95% confidence. We conclude that paleocurrent observations are more appropriate to smaller-scale studies, and regions where external information such as topography, radioisotope analysis and biostratigraphy can provide useful context and constraints.
Numerical Analysis of Deflections of Multi-Layered Beams
NASA Astrophysics Data System (ADS)
Biliński, Tadeusz; Socha, Tomasz
2015-03-01
The paper concerns the rheological bending problem of wooden beams reinforced with embedded composite bars. A theoretical model of the behaviour of a multi-layered beam is presented. The component materials of this beam are described with equations for the linear viscoelastic five-parameter rheological model. Two numerical analysis methods for the long-term response of wood structures are presented. The first method has been developed with SCILAB software. The second one has been developed with the finite element calculation software ABAQUS and user subroutine UMAT. Laboratory investigations were conducted on sample beams of natural dimensions in order to validate the proposed theoretical model and verify numerical simulations. Good agreement between experimental measurements and numerical results is observed.
NASA Astrophysics Data System (ADS)
Nettasana, Tussanee; Craig, James; Tolson, Bryan
2012-11-01
Sustainable management of groundwater resources is vital for development of areas at risk from water-resource over-exploitation. In northeast Thailand, the Phu Thok aquifer is an important water source, particularly in the Thaphra area, where increased groundwater withdrawals may result in water-level decline and saline-water upconing. Three-dimensional finite-difference flow models were developed with MODFLOW to predict the impacts of future pumping on hydraulic heads. Four scenarios of pumping and recharge were defined to evaluate the system response to future usage and climate conditions. Primary model simulations show that groundwater heads will continue to decrease by 4-12 m by the year 2040 at the center of the highly exploited area, under conditions of both increasing pumping and drought. To quantify predictive uncertainty in these estimates, in addition to the primary conceptual model, three alternative conceptual models were used in the simulation of sustainable yields. These alternative models show that, for this case study, a reasonable degree of uncertainty in hydrostratigraphic interpretation is more impactful than uncertainty in recharge distribution or boundary conditions. The uncertainty-analysis results strongly support addressing conceptual-model uncertainty in the practice of groundwater-management modeling. Doing so will better assist decision makers in selecting and implementing robust sustainable strategies.
Analysis of sludge from Hanford K East Basin canisters
Makenas, B.J.; Welsh, T.L.; Baker, R.B.; Hoppe, E.W.; Schmidt, A.J.; Abrefah, J.; Tingey, J.M.; Bredt, P.R.; Golcar, G.R.
1997-09-12
Sludge samples from the canisters in the Hanford K East Basin fuel storage pool have been retrieved and analyzed. Both chemical and physical properties have been determined. The results are to be used to determine the disposition of the bulk of the sludge and to assess the impact of residual sludge on dry storage of the associated intact metallic uranium fuel elements. This report is a summary and review of the data provided by various laboratories. Although raw chemistry data were originally reported on various bases (compositions for as-settled, centrifuged, or dry sludge) this report places all of the data on a common comparable basis. Data were evaluated for internal consistency and consistency with respect to the governing sample analysis plan. Conclusions applicable to sludge disposition and spent fuel storage are drawn where possible.
Application of numerical analysis to one-piece SMC panels
NASA Astrophysics Data System (ADS)
Hirai, Tsuneo; Yamabe, Masashi
A new analytical procedure has been devised for making a detailed analysis of the flow behavior of SMC during the rib-filling process. This procedure employs a combination of flow and deformation analysis techniques, and also a newly added flow analysis technique at the stage just prior to the completion of filling. A numerical model has also been devised for the molding process in which back pressure is applied to minimize sink marks. The model is designed so that the relationship between changes in various molding factors and the resulting severity of sink marks can be analyzed quantitatively.
Integrated numerical methods for hypersonic aircraft cooling systems analysis
NASA Technical Reports Server (NTRS)
Petley, Dennis H.; Jones, Stuart C.; Dziedzic, William M.
1992-01-01
Numerical methods have been developed for the analysis of hypersonic aircraft cooling systems. A general purpose finite difference thermal analysis code is used to determine areas which must be cooled. Complex cooling networks of series and parallel flow can be analyzed using a finite difference computer program. Both internal fluid flow and heat transfer are analyzed, because increased heat flow causes a decrease in the flow of the coolant. The steady state solution is a successive point iterative method. The transient analysis uses implicit forward-backward differencing. Several examples of the use of the program in studies of hypersonic aircraft and rockets are provided.
Experimental and Numerical analysis of Metallic Bellow for Acoustic Performance
NASA Astrophysics Data System (ADS)
Panchwadkar, Amit A.; Awasare, Pradeep J., Dr.; Ingle, Ravidra B., Dr.
2017-08-01
Noise will concern about the work environment of industry. Machinery environment has overall noise which interrupts communication between the workers. This problem of miscommunication and health hazard will make sense to go for noise attenuation. Modification in machine setup may affect the performance of it. Instead of that, Helmholtz resonator principle will be a better option for noise reduction along the transmission path. Resonator has design variables which gives resonating frequency will help us to confirm the frequency range. This paper deals with metallic bellow which behaves like inertial mass under incident sound wave. Sound wave energy is affected by hard boundary condition of resonator and bellow. Metallic bellow is used in combination with resonator to find out Transmission loss (TL). Microphone attachment with FFT analyzer will give the frequency range for numerical analysis. Numerical analysis of bellow and resonator is carried out to summarize the acoustic behavior of bellow. Bellow can be numerically analyzed to check noise attenuation for centrifugal blower. An impedance tube measurement technique is performed to validate the numerical results for assembly. Dimensional and shape modification can be done to get the acoustic performance of bellow.
Maĭor, T Iu; Sheveleva, N G; Sukhanova, L V; Timoshkin, O A; Kiril'chik, S V
2010-11-01
Baikalian cyclopoids represent one of the richest endemic faunas of freshwater cyclopoid copepods. The genus Diacyclops Kiefer, 1927 is the most numerous by species number in the lake. In this work, molecular-phylogenetic analysis of 14 species and 1 sub-species from Lake Baikal and its water catchment basin is performed. The regions of mitochondrial cytochrom-oxydase I (COI) and of nuclear small-subunit 18S rRNA were used as evolution markers. In the obtained set of nucleotide sequences of COT gene, an effect of synonymous substitution saturation is revealed. Baikalian representatives of the genus Diacyclops form at phylogenetic schemes by two markers a monophyletic griup, it suggest their origin from a common ancestral form. Preliminary estimate of the age of this group is 20-25 My.
Statistical Analysis of Acoustic Signal Propagating Through the South China Sea Basin
2016-03-01
ANALYSIS OF ACOUSTIC SIGNAL PROPAGATING THROUGH THE SOUTH CHINA SEA BASIN by Meihuei Chen March 2016 Thesis Advisor... ACOUSTIC SIGNAL PROPAGATING THROUGH THE SOUTH CHINA SEA BASIN 5. FUNDING NUMBERS 6. AUTHOR(S) Meihuei Chen 7. PERFORMING ORGANIZATION NAME(S) AND...China Sea (SCS) basin to study the effects of nonlinear internal waves on 400- Hz acoustic signal propagation. The acoustic arrival structure for this
Recent advances in numerical analysis of structural eigenvalue problems
NASA Technical Reports Server (NTRS)
Gupta, K. K.
1973-01-01
A wide range of eigenvalue problems encountered in practical structural engineering analyses is defined, in which the structures are assumed to be discretized by any suitable technique such as the finite-element method. A review of the usual numerical procedures for the solution of such eigenvalue problems is presented and is followed by an extensive account of recently developed eigenproblem solution procedures. Particular emphasis is placed on the new numerical algorithms and associated computer programs based on the Sturm sequence method. Eigenvalue algorithms developed for efficient solution of natural frequency and buckling problems of structures are presented, as well as some eigenvalue procedures formulated in connection with the solution of quadratic matrix equations associated with free vibration analysis of structures. A new algorithm is described for natural frequency analysis of damped structural systems.
Recent advances in numerical analysis of structural eigenvalue problems
NASA Technical Reports Server (NTRS)
Gupta, K. K.
1973-01-01
A wide range of eigenvalue problems encountered in practical structural engineering analyses is defined, in which the structures are assumed to be discretized by any suitable technique such as the finite-element method. A review of the usual numerical procedures for the solution of such eigenvalue problems is presented and is followed by an extensive account of recently developed eigenproblem solution procedures. Particular emphasis is placed on the new numerical algorithms and associated computer programs based on the Sturm sequence method. Eigenvalue algorithms developed for efficient solution of natural frequency and buckling problems of structures are presented, as well as some eigenvalue procedures formulated in connection with the solution of quadratic matrix equations associated with free vibration analysis of structures. A new algorithm is described for natural frequency analysis of damped structural systems.
NASA Astrophysics Data System (ADS)
de Pablo, M. A.; Márquez, A.; Centeno, J. D.
The Atlantis basin is one of the martian highlands areas where there was proposed the existence of an ancient lake during the early geological history of Mars [1] [2] [3] [4]. The existence of some morphological features inside the basin and in the surrounding area, allow to check the existence of liquid water in the past of the planet. On the other hand, other morphological features indicate the existence of snow and liquid groundwater in recent times. The detailed study of the geomorphologic features allows to make an approach to the hydrological evolution of the Atlantis basin. The study of the geomorphology of this region has been carried out by means of the analysis of MOC high resolution images obtained by the Mars Global Surveyor mission and the THEMIS images, in the visible spectrum, sent by Mars Odyssey spacecrafts. The most clearly morphological feature indicative of the existence of water in the surface of Mars in the past are the numerous channels that end into Atlantis basin from the highest terrains. In addiction to these fluvial channels, the existence of mass flow deposits is also indicative of the existence of water in the area. Some of these slumps are in the internal slopes of impact craters, but others cover huge extensions around the chaotic terrains of the studied area. The lobated ejecta deposits observed in the Atlantis basin region are indicative of the existence of groundwater (solid or liquid) [5]. Serrated reliefs and tables in the borders of the basins are indicative of the existence of a water sheet. Beneath this water sheet some deposits was formed which was eroded, due to the gradual desiccation of the basin, forming the tables and serrated reliefs. The existence of different chaotic terrains in the area implies the existence of huge amounts of water under the surface according to the different models of chaotic terrain formation [6] [7]. The existence of groundwater could be decided by the existence of collapses in the near to the
Analysis of Length Distribution of Drainage Basin Perimeter
NASA Astrophysics Data System (ADS)
Werner, Christian
1982-08-01
To establish a theoretical base for the study of the length distribution of basin perimeters, the paper introduces a descriptive model of the topology of interlocking channel and ridge networks. Assuming topological randomness within and between both, the expected number of links of basin perimeters is derived; for large basin magnitudes n, it approximates a square root function in n. Observed link numbers of perimeters deviate significantly, showing a 0.69 regression exponent for their growth rate relative to the basin magnitude rather than the expected value of 0.5. The spatial constraint of possible perimeter/(area;)½ proportions as defined by the circle is translated into a corresponding topological constraint but fails to provide a sufficient explanation. The paper then explores the possibility that the relatively large length of the perimeter reflects the basin elongation which, following Hack, might be linked to the length of the mainstream. Although basin perimeter, elongation, and mainstream length are highly correlated and the elongation axis is oriented to the outlet in two-thirds of the sample basins, the data indicate that the mainstream link number does not account for the basin elongation, nor does it account for the number of links of the basin perimeter.
Numerical bifurcation analysis of conformal formulations of the Einstein constraints
NASA Astrophysics Data System (ADS)
Holst, M.; Kungurtsev, V.
2011-12-01
The Einstein constraint equations have been the subject of study for more than 50 years. The introduction of the conformal method in the 1970s as a parametrization of initial data for the Einstein equations led to increased interest in the development of a complete solution theory for the constraints, with the theory for constant mean curvature (CMC) spatial slices and closed manifolds completely developed by 1995. The first general non-CMC existence result was establish by Holst et al. in 2008, with extensions to rough data by Holst et al. in 2009, and to vacuum spacetimes by Maxwell in 2009. The non-CMC theory remains mostly open; moreover, recent work of Maxwell on specific symmetry models sheds light on fundamental nonuniqueness problems with the conformal method as a parametrization in non-CMC settings. In parallel with these mathematical developments, computational physicists have uncovered surprising behavior in numerical solutions to the extended conformal thin sandwich formulation of the Einstein constraints. In particular, numerical evidence suggests the existence of multiple solutions with a quadratic fold, and a recent analysis of a simplified model supports this conclusion. In this article, we examine this apparent bifurcation phenomena in a methodical way, using modern techniques in bifurcation theory and in numerical homotopy methods. We first review the evidence for the presence of bifurcation in the Hamiltonian constraint in the time-symmetric case. We give a brief introduction to the mathematical framework for analyzing bifurcation phenomena, and then develop the main ideas behind the construction of numerical homotopy, or path-following, methods in the analysis of bifurcation phenomena. We then apply the continuation software package AUTO to this problem, and verify the presence of the fold with homotopy-based numerical methods. We discuss these results and their physical significance, which lead to some interesting remaining questions to
On the numerical kinematic analysis of general parallel robotic manipulators
Lichun Tommy Wang; Chih Cheng Chen . Dept. of Mechanical Engineering)
1993-06-01
The paper presents a systematic approach for the numerical kinematic analysis of general parallel robotic manipulators. This approach consists of two parts. The first part deals with the structural analysis. Based on graph theory and the Depth First Search algorithm, a method for identifying and orientating the independent kinematic loops of the robot is developed. This method not only facilitates the assignment of the local coordinate systems attached to the robot, but also arranges them in the correct order to allow efficient recursive coordinate transformation. The second part of this approach deals with the displacement analysis. A set of recursion formulae is first developed for computing the forward coordinate transformations, and these formulae are then adopted in a two-phase computational algorithm to obtain the numerical solutions to the direct and the inverse kinematics problems. The two-phase algorithm developed in this paper is not only insensitive to the initial approximation of the solution vector, but also gives a rapid convergence rate. Furthermore, it is also useful for finding multiple solutions for the robot as well as for continuous trajectory planning, as shown by the numerical examples presented in this paper.
Srisuk, K; Sriboonlue, V; Buaphan, C; Archvichai, L; Youngme, W; Satarak, P; Jaruchaikul, S
2001-01-01
The objective of the project is to establish a conceptual groundwater model over the lower Nam Kam Basin in order to apply a numerical technique for the prediction of the impact of saline water transport due to the proposed weir across the Nam Kam River. Hydrogeological investigations including mapping, drilling, piezometer installations and monitoring were systematically conducted during 1997 to 1998. Brackish groundwater is saturated under the area with a depth of 30-60 m. Groundwater regionally flows from the south (the Phu Phan Range) to the north and discharges to the Nam Kam River. Another direction is from the northern region to the southern region, discharging to the central region. A two-dimensional model was constructed along the principal gradient in the NW-SE direction. There are several local recharge and discharge areas across the Nam Kam floodplain. A local groundwater flow is active within the depth of 2 m to 30 m below the ground surface within the sand and gravel unit. Simulations were calibrated with hydraulic heads and salinity of groundwater in the piezometers. It is found that the recharge and evapotranspiration rates are 1% to 40% of the rainfall and 10% to 15% of a pan evaporation, respectively. The ranges of horizontal hydraulic conductivity to vertical hydraulic conductivity are 0.1 to 0.01. The possible longitudinal dispersivity values of the hydrostratigraphic units are 20 m to 500 m, but the transverse dispersivity is less than the longitude by one order of magnitude. The comparison of calculated heads and measured heads give a root mean square error of less than 1 m. The different salinity concentrations are still in a range of 2000-5000 mg/l. Ten year simulation of saline water transport indicates that the reservoir ponding with water level at +140.5 m above mean sea level may divert groundwater flow and discharging to the northern boundary of the reservoir at Ban Don Kao.
Wahid, Ali Salim, Ahmed Mohamed Ahmed Yusoff, Wan Ismail Wan; Gaafar, Gamal Ragab
2016-02-01
Geostatistics or statistical approach is based on the studies of temporal and spatial trend, which depend upon spatial relationships to model known information of variable(s) at unsampled locations. The statistical technique known as kriging was used for petrophycial and facies analysis, which help to assume spatial relationship to model the geological continuity between the known data and the unknown to produce a single best guess of the unknown. Kriging is also known as optimal interpolation technique, which facilitate to generate best linear unbiased estimation of each horizon. The idea is to construct a numerical model of the lithofacies and rock properties that honor available data and further integrate with interpreting seismic sections, techtonostratigraphy chart with sea level curve (short term) and regional tectonics of the study area to find the structural and stratigraphic growth history of the NW Bonaparte Basin. By using kriging technique the models were built which help to estimate different parameters like horizons, facies, and porosities in the study area. The variograms were used to determine for identification of spatial relationship between data which help to find the depositional history of the North West (NW) Bonaparte Basin.
Clustered Numerical Data Analysis Using Markov Lie Monoid Based Networks
NASA Astrophysics Data System (ADS)
Johnson, Joseph
2016-03-01
We have designed and build an optimal numerical standardization algorithm that links numerical values with their associated units, error level, and defining metadata thus supporting automated data exchange and new levels of artificial intelligence (AI). The software manages all dimensional and error analysis and computational tracing. Tables of entities verses properties of these generalized numbers (called ``metanumbers'') support a transformation of each table into a network among the entities and another network among their properties where the network connection matrix is based upon a proximity metric between the two items. We previously proved that every network is isomorphic to the Lie algebra that generates continuous Markov transformations. We have also shown that the eigenvectors of these Markov matrices provide an agnostic clustering of the underlying patterns. We will present this methodology and show how our new work on conversion of scientific numerical data through this process can reveal underlying information clusters ordered by the eigenvalues. We will also show how the linking of clusters from different tables can be used to form a ``supernet'' of all numerical information supporting new initiatives in AI.
K West Basin Sand Filter Backwash Sample Analysis
Fiskum, Sandra K.; Smoot, Margaret R.; Coffey, Deborah S.; Pool, Karl N.
2016-03-01
A sand filter is used to help maintain water clarity at the K West Basin where highly radioactive sludge is stored. Eventually that sand filter will require disposal. The radionuclide content of the solids trapped in the sand filter will affect the selection of the sand filter disposal pathway. The Pacific Northwest National Laboratory (PNNL) was contracted by the K Basin Operations & Plateau Remediation Project (operations contractor CH2M Hill) to analyze the radionuclide content of the solids collected from the backwash of the K West Basin sand filter. The radionuclide composition in the sand filter backwash solids will be used by CH2M Hill to determine if the sand filter media and retained sludge solids will be designated as transuranic waste for disposal purposes or can be processed through less expensive means. On October 19, 2015, K Basin Operations & Plateau Remediation Project staff backwashed the sand filter into the North Load-Out Pit (NLOP) and immediately collected sample slurry from a sampling tube positioned 24 in. above the NLOP floor. The 764 g sand filter backwash slurry sample, KW-105 SFBW-001, was submitted to PNNL for analysis on October 20, 2015. Solids from the slurry sample were consolidated into two samples (i.e., a primary and a duplicate sample) by centrifuging and measured for mass (0.82 g combined – wet centrifuged solids basis) and volume (0.80 mL combined). The solids were a dark brown/orange color, consistent with iron oxide/hydroxide. The solids were dried; the combined dry solids mass was 0.1113 g, corresponding to 0.0146 weight percent (wt%) solids in the original submitted sample slurry. The solids were acid-digested using nitric and hydrochloric acids. Insoluble solids developed upon dilution with 0.5 M HNO_{3}, corresponding to an average 6.5 wt% of the initial dry solids content. The acid digestate and insoluble solids were analyzed separately by gamma spectrometry. Nominally, 7.7% of the ^{60}Co was present
Asymptotic/numerical analysis of supersonic propeller noise
NASA Technical Reports Server (NTRS)
Myers, M. K.; Wydeven, R.
1989-01-01
An asymptotic analysis based on the Mach surface structure of the field of a supersonic helical source distribution is applied to predict thickness and loading noise radiated by high speed propeller blades. The theory utilizes an integral representation of the Ffowcs-Williams Hawkings equation in a fully linearized form. The asymptotic results are used for chordwise strips of the blade, while required spanwise integrations are performed numerically. The form of the analysis enables predicted waveforms to be interpreted in terms of Mach surface propagation. A computer code developed to implement the theory is described and found to yield results in close agreement with more exact computations.
Asymptotic/numerical analysis of supersonic propeller noise
NASA Technical Reports Server (NTRS)
Myers, M. K.; Wydeven, R.
1989-01-01
An asymptotic analysis based on the Mach surface structure of the field of a supersonic helical source distribution is applied to predict thickness and loading noise radiated by high speed propeller blades. The theory utilizes an integral representation of the Ffowcs-Williams Hawkings equation in a fully linearized form. The asymptotic results are used for chordwise strips of the blade, while required spanwise integrations are performed numerically. The form of the analysis enables predicted waveforms to be interpreted in terms of Mach surface propagation. A computer code developed to implement the theory is described and found to yield results in close agreement with more exact computations.
Numerical analysis on thermal drilling of aluminum metal matrix composite
NASA Astrophysics Data System (ADS)
Hynes, N. Rajesh Jesudoss; Maheshwaran, M. V.
2016-05-01
The work-material deformation is very large and both the tool and workpiece temperatures are high in thermal drilling. Modeling is a necessary tool to understand the material flow, temperatures, stress, and strains, which are difficult to measure experimentally during thermal drilling. The numerical analysis of thermal drilling process of aluminum metal matrix composite has been done in the present work. In this analysis the heat flux of different stages is calculated. The calculated heat flux is applied on the surface of work piece and thermal distribution is predicted in different stages during the thermal drilling process.
Gardemal, M.; Sofer, Z.; Womer, M.; Sun Xiao Hong
1996-12-31
An integrated hydrocarbon systems evaluation was undertaken in the Bozhong and Liaodong Bay areas of the Bohai Basin in an effort to delineate trends and clarify risks for value-based bid decisions. The Bohai Basin is part of the North China Basin (currently producing >1.2 MMBO/D), which is an intracontinental rift basin 200,000 km{sup 2} in size and contains up to 11 km of Tertiary continental to lacustrine rocks. Geochemical analyses of biomarker data (GC/MS) from 43 oils and rock extracts from 41 wells indicate that two main types of lacustrine oils, both generated from the Shahejie 3 Formation, can be distinguished. One type, from the Upper Shahejie 3, has algal affinities, high relative gammacerane content, and is generated and expelled at vitrinite reflectance equivalents (VRE) of 0.5 to 0.6 %, based on sterane isomer ratios. The other oil type, from the Lower Shahejie 3, has higher bacterial relative to algal input, lower relative gammacerane content, and is generated and expelled at 0.8 to 0.9 % VRE. Basin modeling studies and migration pathway analyses were integrated with results from the geochemical work to calibrate the thermal model, estimate timing of generation and expulsion, and calculate potential resources available for migration to traps. A rifting heat flow thermal model was calibrated to measured maturity data (Ro, Tmax, and VRE from sterane ratios) and corrected bottom hole temperature data for 30 wells throughout the basin. The time of major Tertiary rifting was estimated at 55-38 mybp, and beta stretching factors of 1.6 to 2.0 were used. Continuous down-well estimates of hydrocarbon yields for resource estimates were calculated from an empirical relationship between measured TOC and Hydrogen Indices (HI) from well samples and{Delta} log R calculations of TOC and HI.
Gardemal, M.; Sofer, Z.; Womer, M. ); Sun Xiao Hong )
1996-01-01
An integrated hydrocarbon systems evaluation was undertaken in the Bozhong and Liaodong Bay areas of the Bohai Basin in an effort to delineate trends and clarify risks for value-based bid decisions. The Bohai Basin is part of the North China Basin (currently producing >1.2 MMBO/D), which is an intracontinental rift basin 200,000 km[sup 2] in size and contains up to 11 km of Tertiary continental to lacustrine rocks. Geochemical analyses of biomarker data (GC/MS) from 43 oils and rock extracts from 41 wells indicate that two main types of lacustrine oils, both generated from the Shahejie 3 Formation, can be distinguished. One type, from the Upper Shahejie 3, has algal affinities, high relative gammacerane content, and is generated and expelled at vitrinite reflectance equivalents (VRE) of 0.5 to 0.6 %, based on sterane isomer ratios. The other oil type, from the Lower Shahejie 3, has higher bacterial relative to algal input, lower relative gammacerane content, and is generated and expelled at 0.8 to 0.9 % VRE. Basin modeling studies and migration pathway analyses were integrated with results from the geochemical work to calibrate the thermal model, estimate timing of generation and expulsion, and calculate potential resources available for migration to traps. A rifting heat flow thermal model was calibrated to measured maturity data (Ro, Tmax, and VRE from sterane ratios) and corrected bottom hole temperature data for 30 wells throughout the basin. The time of major Tertiary rifting was estimated at 55-38 mybp, and beta stretching factors of 1.6 to 2.0 were used. Continuous down-well estimates of hydrocarbon yields for resource estimates were calculated from an empirical relationship between measured TOC and Hydrogen Indices (HI) from well samples and[Delta] log R calculations of TOC and HI.
Analysis of Ignition Testing on K-West Basin Fuel
J. Abrefah; F.H. Huang; W.M. Gerry; W.J. Gray; S.C. Marschman; T.A. Thornton
1999-08-10
Approximately 2100 metric tons of spent nuclear fuel (SNF) discharged from the N-Reactor have been stored underwater at the K-Basins in the 100 Area of the Hanford Site. The spent fuel has been stored in the K-East Basin since 1975 and in the K-West Basin since 1981. Some of the SNF elements in these basins have corroded because of various breaches in the Zircaloy cladding that occurred during fuel discharge operations and/or subsequent handling and storage in the basins. Consequently, radioactive material in the fuel has been released into the basin water, and water has leaked from the K-East Basin into the soil below. To protect the Columbia River, which is only 380 m from the basins, the SNF is scheduled to be removed and transported for interim dry storage in the 200 East Area, in the central portion of the Site. However, before being shipped, the corroded fuel elements will be loaded into Multi-Canister OverPacks and conditioned. The conditioning process will be selected based on the Integrated Process Strategy (IPS) (WHC 1995), which was prepared on the basis of the dry storage concept developed by the Independent Technical Assessment (ITA) team (ITA 1994).
Numeral-Incorporating Roots in Numeral Systems: A Comparative Analysis of Two Sign Languages
ERIC Educational Resources Information Center
Fuentes, Mariana; Massone, Maria Ignacia; Fernandez-Viader, Maria del Pilar; Makotrinsky, Alejandro; Pulgarin, Francisca
2010-01-01
Numeral-incorporating roots in the numeral systems of Argentine Sign Language (LSA) and Catalan Sign Language (LSC), as well as the main features of the number systems of both languages, are described and compared. Informants discussed the use of numerals and roots in both languages (in most cases in natural contexts). Ten informants took part in…
Numeral-Incorporating Roots in Numeral Systems: A Comparative Analysis of Two Sign Languages
ERIC Educational Resources Information Center
Fuentes, Mariana; Massone, Maria Ignacia; Fernandez-Viader, Maria del Pilar; Makotrinsky, Alejandro; Pulgarin, Francisca
2010-01-01
Numeral-incorporating roots in the numeral systems of Argentine Sign Language (LSA) and Catalan Sign Language (LSC), as well as the main features of the number systems of both languages, are described and compared. Informants discussed the use of numerals and roots in both languages (in most cases in natural contexts). Ten informants took part in…
A numerical model and spreadsheet interface for pumping test analysis.
Johnson, G S; Cosgrove, D M; Frederick, D B
2001-01-01
Curve-matching techniques have been the standard method of aquifer test analysis for several decades. A variety of techniques provide the capability of evaluating test data from confined, unconfined, leaky aquitard, and other conditions. Each technique, however, is accompanied by a set of assumptions, and evaluation of a combination of conditions can be complicated or impossible due to intractable mathematics or nonuniqueness of the solution. Numerical modeling of pumping tests provides two major advantages: (1) the user can choose which properties to calibrate and what assumptions to make; and (2) in the calibration process the user is gaining insights into the conceptual model of the flow system and uncertainties in the analysis. Routine numerical modeling of pumping tests is now practical due to computer hardware and software advances of the last decade. The RADFLOW model and spreadsheet interface presented in this paper is an easy-to-use numerical model for estimation of aquifer properties from pumping test data. Layered conceptual models and their properties are evaluated in a trial-and-error estimation procedure. The RADFLOW model can treat most combinations of confined, unconfined, leaky aquitard, partial penetration, and borehole storage conditions. RADFLOW is especially useful in stratified aquifer systems with no identifiable lateral boundaries. It has been verified to several analytical solutions and has been applied in the Snake River Plain Aquifer to develop and test conceptual models and provide estimates of aquifer properties. Because the model assumes axially symmetrical flow, it is limited to representing multiple aquifer layers that are laterally continuous.
Ernest Mancini
2001-03-01
Part 3 (Petroleum System Modeling of the Jurassic Smackover Formation) objectives are to provide an analysis of the Smackover petroleum system in Years 4 and 5 of the project and to transfer effectively the research results to producers through workshops and topical reports. Work Accomplished (Year 5): Task 1 - Basin Flow - Basin flow modeling has been completed and the topical report has been submitted to the U.S. DOE for review. Task 2 - Petroleum Source Rocks - Work on the characterization of Smackover petroleum source rocks has been integrated into the basin flow model. The information on the source rocks is being prepared for inclusion in the final report. Task 3 - Petroleum Reservoirs - Work on the characterization of Smackover petroleum reservoirs continues. The cores to be described have been identified and many of the cores for the eastern and western parts of the basin have been described. Task 4 - Reservoir Diagenesis - Work on reservoir diagenesis continues. Samples from the cores selected for the reservoir characterization are being used for this task. Task 5 - Underdeveloped Reservoirs - Two underdeveloped Smackover reservoirs have been identified. They are the microbial reef and shoal reservoirs. Work Planned (Year 5): Task 1 - Basin Flow - This task has been completed and the topical report has been submitted to the U.S. DOE. Task 2 - Petroleum Source Rocks - Petroleum source rock information will continue to be prepared for the final report. Task 3 - Petroleum Reservoirs - Characterization of petroleum reservoirs will continue through core studies. Task 4 - Reservoir Diagenesis - Characterization of reservoir diagenesis will continue through petrographic analysis. Task 5 - Underdeveloped Reservoirs - Study of Smackover underdeveloped reservoirs will continue with focus on the microbial reef and shoal reservoirs.
1-D Numerical Analysis of ABCC Engine Performance
NASA Technical Reports Server (NTRS)
Holden, Richard
1999-01-01
ABCC engine combines air breathing and rocket engine into a single engine to increase the specific impulse over an entire flight trajectory. Except for the heat source, the basic operation of the ABCC is similar to the basic operation of the RBCC engine. The ABCC is intended to have a higher specific impulse than the RBCC for single stage Earth to orbit vehicle. Computational fluid dynamics (CFD) is a useful tool for the analysis of complex transport processes in various components in ABCC propulsion system. The objective of the present research was to develop a transient 1-D numerical model using conservation of mass, linear momentum, and energy equations that could be used to predict flow behavior throughout a generic ABCC engine following a flight path. At specific points during the development of the 1-D numerical model a myriad of tests were performed to prove the program produced consistent, realistic numbers that follow compressible flow theory for various inlet conditions.
Numerical Ergonomics Analysis in Operation Environment of CNC Machine
NASA Astrophysics Data System (ADS)
Wong, S. F.; Yang, Z. X.
2010-05-01
The performance of operator will be affected by different operation environments [1]. Moreover, poor operation environment may cause health problems of the operator [2]. Physical and psychological considerations are two main factors that will affect the performance of operator under different conditions of operation environment. In this paper, applying scientific and systematic methods find out the pivot elements in the field of physical and psychological factors. There are five main factors including light, temperature, noise, air flow and space that are analyzed. A numerical ergonomics model has been built up regarding the analysis results which can support to advance the design of operation environment. Moreover, the output of numerical ergonomic model can provide the safe, comfortable, more productive conditions for the operator.
Numerical Analysis on Double Dome Stretching Tests of Woven Composites
NASA Astrophysics Data System (ADS)
Lee, Wonoh; Cao, Jian; Chen, Julie; Sherwood, James
2007-04-01
As a result of international corporative benchmark works, material characterization of the woven fabric reinforced composites has been examined to better understand their mechanical properties and to provide the process design information for numerical analysis. Here, in order to predict thermo-forming behaviors of woven composites, the double dome stretching tests have been numerically performed for the balanced plain weave. To account for the change of fiber orientation under the large deformation, the non-orthogonal constitutive model has been utilized and nonlinear friction behavior is incorporated in the simulation. Also the equivalent material properties based on the contact status have been used for the thermo-stamping process. Blank draw-in, punch force history and fiber orientation after forming will be reported.
1-D Numerical Analysis of ABCC Engine Performance
NASA Technical Reports Server (NTRS)
Holden, Richard
1999-01-01
ABCC engine combines air breathing and rocket engine into a single engine to increase the specific impulse over an entire flight trajectory. Except for the heat source, the basic operation of the ABCC is similar to the basic operation of the RBCC engine. The ABCC is intended to have a higher specific impulse than the RBCC for single stage Earth to orbit vehicle. Computational fluid dynamics (CFD) is a useful tool for the analysis of complex transport processes in various components in ABCC propulsion system. The objective of the present research was to develop a transient 1-D numerical model using conservation of mass, linear momentum, and energy equations that could be used to predict flow behavior throughout a generic ABCC engine following a flight path. At specific points during the development of the 1-D numerical model a myriad of tests were performed to prove the program produced consistent, realistic numbers that follow compressible flow theory for various inlet conditions.
NASA Astrophysics Data System (ADS)
Anka, Z.; Rodrigues, E.; Ostanin, I.; di Primio, R.; Stoddart, D.; Horsfield, B.
2012-04-01
The Hammerfest Basin, located in the SW Barents Sea, is characterized by present-day under-filled hydrocarbon accumulations, which are known to have leaked in the past (Dimakis, 1998; Ohm et al. 2008). Late Cenozoic erosion and high latitude glaciations are thought to have driven the redistribution and leakage of these thermogenic fluids providing a source of thermogenic methane to the hydrosphere. The timing, extent and driving factors for the leakage events are still largely unconstrained. Therefore, we investigated present and past leakage of liquid and gaseous hydrocarbons over the Snøhvit and Albatross gas fields of the Hammerfest Basin and analyse its dynamics in response to multiple phases of tectonic uplift and glaciations by means of a combined approach of numerical modelling and interpretation of a high resolution 3D seismic reflection cube. Our data-constrained 3D basin model of the basin allowed us to quantify the masses of hydrocarbons generated, accumulated and eventually leaked from the reservoirs during the evolution of the basin. Particular emphasis was placed on analysing the fate of leaked volumes of methane within the dynamics of Plio-Quaternary glacial cycles and possible formation or destabilization of gas hydrate deposits. Besides reproducing quite accurately the composition and volume of the hydrocarbons -particularly the gaseous phase- present in the main reservoirs, the model predicts the development of overpressures in the reservoirs due to the ice loading of the basin during the glacial periods. Predicted reservoir pressure fluctuations derived from cyclic loading-unloading during the glacial-interglacial periods are up to 5 MPa. The under-filled nature of the present-day accumulations would result from leakage events during the episodes of glacial retreat, in the transition from glacial to interglacial periods. Considerations of the gas hydrate stability conditions in the basin during the time span between 1.00Ma and ≈11,500 years
Anderson, M.; Matti, J.; Jachens, R.
2004-01-01
The San Bernardino basin is an area of Quaternary extension between the San Jacinto and San Andreas Fault zones in southern California. New gravity data are combined with aeromagnetic data to produce two- and three-dimensional models of the basin floor. These models are used to identify specific faults that have normal displacements. In addition, aeromagnetic maps of the basin constrain strike-slip offset on many faults. Relocated seismicity, focal mechanisms, and a seismic reflection profile for the basin area support interpretations of the gravity and magnetic anomalies. The shape of the basin revealed by our interpretations is different from past interpretations, broadening its areal extent while confining the deepest parts to an area along the modern San Jacinto fault, west of the city of San Bernardino. Through these geophysical observations and related geologic information, we propose a model for the development of the basin. The San Jacinto fault-related strike-slip displacements started on fault strands in the basin having a stepping geometry thus forming a pull-apart graben, and finally cut through the graben in a simpler, bending geometry. In this model, the San Bernardino strand of the San Andreas Fault has little influence on the formation of the basin. The deep, central part of the basin resembles classic pull-apart structures and our model describes a high level of detail for this structure that can be compared to other pull-apart structures as well as analog and numerical models in order to better understand timing and kinematics of pull-apart basin formation. Copyright 2004 by the American Geophysical Union.
Mas-Pla, Josep; Font, Eva; Astui, Oihane; Menció, Anna; Rodríguez-Florit, Agustí; Folch, Albert; Brusi, David; Pérez-Paricio, Alfredo
2012-12-01
Stream flow, as a part of a basin hydrological cycle, will be sensible to water scarcity as a result of climate change. Stream vulnerability should then be evaluated as a key component of the basin water budget. Numerical flow modeling has been applied to an alluvial formation in a small mountain basin to evaluate the stream-aquifer relationship under these future scenarios. The Arbúcies River basin (116 km(2)) is located in the Catalan Inner Basins (NE Spain) and its lower reach, which is related to an alluvial aquifer, usually becomes dry during the summer period. This study seeks to determine the origin of such discharge losses whether from natural stream leakage and/or induced capture due to groundwater withdrawal. Our goal is also investigating how discharge variations from the basin headwaters, representing potential effects of climate change, may affect stream flow, aquifer recharge, and finally environmental preservation and human supply. A numerical flow model of the alluvial aquifer, based on MODFLOW and especially in the STREAM routine, reproduced the flow system after the usual calibration. Results indicate that, in the average, stream flow provides more than 50% of the water inputs to the alluvial aquifer, being responsible for the amount of stored water resources and for satisfying groundwater exploitation for human needs. Detailed simulations using daily time-steps permit setting threshold values for the stream flow entering at the beginning of the studied area so surface discharge is maintained along the whole watercourse and ecological flow requirements are satisfied as well. The effects of predicted rainfall and temperature variations on the Arbúcies River alluvial aquifer water balance are also discussed from the outcomes of the simulations. Finally, model results indicate the relevance of headwater discharge management under future climate scenarios to preserve downstream hydrological processes. They also point out that small mountain basins
Numerical simulation of fault slip and its dynamic source in the main fault zone of Taiyuan Basin
NASA Astrophysics Data System (ADS)
Liao, L.; Li, P. E.
2017-06-01
There are three earthquakes which magnitude over 6 have been recorded in Taiyuan Basin located Shanxi seismic belt which has high seismicity. The tectonic activity of Taiyuan basin is mainly controlled by the Jiaocheng fault and Taigu fault near Taiyuan city, So the potential seismic risk is concerned. The previous research results show that the fault slip rate is directly related to the magnitude of the earthquake, and the larger fault slip rate indicates higher seismic risk. In this research, geological and geophysical data are conclude to construct a finite element model of Taiyuan Basin to simulate the fault slip of Jiaocheng fault and Taigu fault after long term tectonic evolution, the stress field is simulated to compare with the focal mechanism of small earthquakes to analyze the dynamic source of Taiyuan basin tectonic activity. The results show that the extrusion of the Ordos block from west to East is the main source of tectonic activities in the Taiyuan basin. The extrusion of Ordos block is the main cause of stress in this area shows tensile property in the north-west direction and compressive property in the north-east direction in Taiyuan Basin. In addition, the slip state simulation results show that the Jiaocheng fault slip rate is higher than that of the Taigu fault, the slip rate of northern Jiaocheng fault is higher than that of southern Jiaocheng fault.
Numerical analysis of frictional heat generation in bicycle disc brake
NASA Astrophysics Data System (ADS)
Tahmid, Shadman; Alam, Saima
2017-06-01
Precise braking operations are pivotal to ensure safety in modern day vehicle designs. Brakes are mechanical devices for increasing the frictional resistance that obstructs the turning motion of vehicle wheels by absorbing either kinetic, potential energy or both while in action. This absorbed energy appears in the form of heat. Stress, distribution of friction on surface, frictional heat generation, material and geometry are the major controlling factors for efficiency of braking operations. Frictional heat generation and its effective dissipation is one of the most predominant of these factors and hence it is the focus of this study. The purpose of this study is to analyze the thermal behavior of a full bicycle disc brake using finite element method. Sequential thermal structured method based on Ansys 14.5 is used to carry out the numerical simulation for evaluating the variation of total heat flux and temperature profiles with respect to time. The analysis model was studied experimentally and results obtained by numerical analysis were within 3% of the experimental result for maximum temperature. The model is thus adequately validated to be followed for a similar analysis on bicycle brakes.
Numerical MLPG Analysis of Piezoelectric Sensor in Structures
NASA Astrophysics Data System (ADS)
Staňák, Peter; Sládek, Ján; Sládek, Vladimír; Krahulec, Slavomír
2014-07-01
The paper deals with a numerical analysis of the electro-mechanical response of piezoelectric sensors subjected to an external non-uniform displacement field. The meshless method based on the local Petrov-Galerkin (MLPG) approach is utilized for the numerical solution of a boundary value problem for the coupled electro-mechanical fields that characterize the piezoelectric material. The sensor is modeled as a 3-D piezoelectric solid. The transient effects are not considered. Using the present MLPG approach, the assumed solid of the cylindrical shape is discretized with nodal points only, and a small spherical subdomain is introduced around each nodal point. Local integral equations constructed from the weak form of governing PDEs are defined over these local subdomains. A moving least-squares (MLS) approximation scheme is used to approximate the spatial variations of the unknown field variables, and the Heaviside unit step function is used as a test function. The electric field induced on the sensor is studied in a numerical example for two loading scenarios.
Schreffler, Curtis L.
1996-01-01
A water-use analysis computer program was developed for the Neshaminy Creek Basin to assist in managing and allocating water resources in the basin. The program was developed for IBM-compatible personal computers. Basin analysis and the methodologies developed for the Neshaminy Creek Basin can be transferred to other watersheds. The development and structure of the water-use analysis program is documented in this report. The report also serves as a user's guide. The program uses common relational database-management software that allows for water use-data input, editing, updating and output and can be used to generate a watershed water-use analysis report. The watershed-analysis report lists summations of public-supply well withdrawals; a combination of industrial, commercial, institutional, and ground-water irrigation well withdrawals; spray irrigation systems; a combination of public, industrial, and private surface-water withdrawals; wastewater-tratement-facility dishcarges; estimates of aggregate domestic ground-water withdrawals on an areal basin or subbasin basis; imports and exports of wastewater across basin or subbasin divides; imports and exports of public water supplies across basin or subbasin divides; estimates of evaporative loss and consumptive loss from produce incorporation; industrial septic-system discharges to ground water; and ground-water well-permit allocations.
Schreffler, Curtis L.
1996-01-01
A water-use analysis computer program was developed for the Neshaminy Creek Basin to assist in managing and allocating water resources in the basin. The program was developed for IBM-compatible personal computers. Basin analysis and the methodologies developed for the Neshaminy Creek Basin can be transferred to other watersheds. The development and structure of the water-use analysis program is documented in this report. The report also serves as a user's guide. The program uses common relational database-management software that allows for water use-data input, editing, updating and output and can be used to generate a watershed water-use analysis report. The watershed-analysis report lists summations of public-supply well withdrawals; a combination of industrial, commercial, institutional, and ground-water irrigation well withdrawals; spray irrigation systems; a combination of public, industrial, and private surface-water withdrawals; wastewater-tratement-facility dishcarges; estimates of aggregate domestic ground-water withdrawals on an areal basin or subbasin basis; imports and exports of wastewater across basin or subbasin divides; imports and exports of public water supplies across basin or subbasin divides; estimates of evaporative loss and consumptive loss from produce incorporation; industrial septic-system discharges to ground water; and ground-water well-permit allocations.
Numerical Analysis of Permittivity with Loss in Isotropic Binary Composites
1992-06-01
and higher breakdown r(m’V,.(tcO,. This report describes the numerical analysis of permittivity in iso- t-rojif. Honary composite dielectrics through...are numbered sequentially from the ground electrode and in relation to (x,y,z) coordinate location. The h node number is i = x + (y-l) Xm + (z-l) Xm Ym...6 N L .4 0 2 aB .2 .3 4 .5 .6 7 a 9 1 H Uclume fraction Figure 9. Two-dimensional composite mixture, A-windowed, with constituent permittivities of E
Numerical model of solar dynamic radiator for parametric analysis
NASA Technical Reports Server (NTRS)
Rhatigan, Jennifer L.
1989-01-01
Growth power requirements for Space Station Freedom will be met through addition of 25 kW solar dynamic (SD) power modules. Extensive thermal and power cycle modeling capabilities have been developed which are powerful tools in Station design and analysis, but which prove cumbersome and costly for simple component preliminary design studies. In order to aid in refining the SD radiator to the mature design stage, a simple and flexible numerical model was developed. The model simulates heat transfer and fluid flow performance of the radiator and calculates area mass and impact survivability for many combinations of flow tube and panel configurations, fluid and material properties, and environmental and cycle variations.
Microcomputer numerical analysis system for gas dynamics application
NASA Technical Reports Server (NTRS)
Prozan, R. J.
1983-01-01
The original objective (scope) of the effort was to deliver a microcomputer version of the Continuum gas dynamic numerical analysis on existing NASA equipment. It became apparent during the course of the contract that the interests of NASA would be much better served by the delivery of a dedicated system designed and developed by Continuum, which would provide NASA with additional hardware ideally suited to the specific task at no increase in cost. Accordingly, the contract was modified to reflect this new development. The details of the modification and the delivered capability will be discussed in greater detail in the ensuing technical discussion.
An improved numerical model for wave rotor design and analysis
NASA Technical Reports Server (NTRS)
Paxson, Daniel E.; Wilson, Jack
1992-01-01
A numerical model has been developed which can predict both the unsteady flows within a wave rotor and the steady averaged flows in the ports. The model is based on the assumptions of one-dimensional, unsteady, and perfect gas flow. Besides the dominant wave behavior, it is also capable of predicting the effects of finite tube opening time, leakage from the tube ends, and viscosity. The relative simplicity of the model makes it useful for design, optimization, and analysis of wave rotor cycles for any application. This paper discusses some details of the model and presents comparisons between the model and two laboratory wave rotor experiments.
An improved numerical model for wave rotor design and analysis
NASA Technical Reports Server (NTRS)
Paxson, Daniel E.; Wilson, Jack
1993-01-01
A numerical model has been developed which can predict both the unsteady flows within a wave rotor and the steady averaged flows in the ports. The model is based on the assumptions of one-dimensional, unsteady, and perfect gas flow. Besides the dominant wave behavior, it is also capable of predicting the effects of finite tube opening time, leakage from the tube ends, and viscosity. The relative simplicity of the model makes it useful for design, optimization, and analysis of wave rotor cycles for any application. This paper discusses some details of the model and presents comparisons between the model and two laboratory wave rotor experiments.
Diffraction patterns from multiple tilted laser apertures: numerical analysis
NASA Astrophysics Data System (ADS)
Kovalev, Anton V.; Polyakov, Vadim M.
2016-03-01
We propose a Rayleigh-Sommerfeld based method for numerical calculation of multiple tilted apertures near and far field diffraction patterns. Method is based on iterative procedure of fast Fourier transform based circular convolution of the initial field complex amplitudes distribution and impulse response function modified in order to account aperture and observation planes mutual tilt. The method is computationally efficient and has good accordance with the results of experimental diffraction patterns and can be applied for analysis of spatial noises occurring in master oscillator power amplifier laser systems. The example of diffraction simulation for a Phobos-Ground laser rangefinder amplifier is demonstrated.
Numerical analysis of decoy state quantum key distribution protocols
Harrington, Jim W; Rice, Patrick R
2008-01-01
Decoy state protocols are a useful tool for many quantum key distribution systems implemented with weak coherent pulses, allowing significantly better secret bit rates and longer maximum distances. In this paper we present a method to numerically find optimal three-level protocols, and we examine how the secret bit rate and the optimized parameters are dependent on various system properties, such as session length, transmission loss, and visibility. Additionally, we show how to modify the decoy state analysis to handle partially distinguishable decoy states as well as uncertainty in the prepared intensities.
Numerical model of solar dynamic radiator for parametric analysis
NASA Technical Reports Server (NTRS)
Rhatigan, Jennifer L.
1989-01-01
Growth power requirements for Space Station Freedom will be met through addition of 25 kW solar dynamic (SD) power modules. Extensive thermal and power cycle modeling capabilities have been developed which are powerful tools in Station design and analysis, but which prove cumbersome and costly for simple component preliminary design studies. In order to aid in refining the SD radiator to the mature design stage, a simple and flexible numerical model was developed. The model simulates heat transfer and fluid flow performance of the radiator and calculates area mass and impact survivability for many combinations of flow tube and panel configurations, fluid and material properties, and environmental and cycle variations.
An analysis of stream temperatures, Green River Basin, Wyoming
Lowham, H.W.
1978-01-01
A method for estimating temperatures of streams in the Green River basin, Wyoming, utilizes a regional model for estimating mean daily temperatures of streams at unmeasured sites. The regional model was developed by describing annual temperature patterns at 43 measured sites and by applying the harmonic function T = M + A -sin (0.0172 t + C)- where: T is mean daily temperature; M, A, and C are harmonic coefficients calculated from data for each stream-temperature station; and t is the day of the water year. Application of the equation for estimating temperatures at unmeasured sites requires regionalized estimates of M, A, and C. Regional estimates were developed with the aid of multiple-regression techniques, whereby the calculated harmonic coefficients were regressed against physical and climatic characteristics of the stream-temperature stations. Stream elevation was a significant factor affecting water temperature. Analysis of areal and temporal variations in temperature showed that springs, irrigation return flows, and reservoir storage were affecting reaches of several major streams. (Woodard-USGS)
Geologic Analysis of Priority Basins for Exploration and Drilling
Carroll, H.B.; Reeves, T.K.
1999-04-27
There has been a substantial decline in both exploratory drilling and seismic field crew activity in the United States over the last 10 years, due primarily to the declining price of oil. To reverse this trend and to preserve the entrepreneurial independent operator, the U.S. DOE is attempting to encourage hydrocarbon exploration activities in some of the under exploited regions of the United States. This goal is being accomplished by conducting broad regional reviews of potentially prospective areas within the lower 48 states. Data are being collected on selected areas, and studies are being done on a regional scale generally unavailable to the smaller independent. The results of this work will be made available to the public to encourage the undertaking of operations in areas which have been overlooked until this project. Fifteen criteria have been developed for the selection of study areas. Eight regions have been identified where regional geologic analysis will be performed. This report discusses preliminary findings concerning the geology, early tectonic history, structure and potential unconventional source rocks for the Black Mesa basin and South Central states region, the two highest priority study areas.
Analysis of urban storm-water quality for seven basins near Portland, Oregon
Miller, Timothy L.; McKenzie, Stuart W.
1978-01-01
Over a 1.5-year period, water-quality data were collected for seven small drainage basins in urban aeas of Portland, Oreg. Analysis of the data followed three approaches. First, the constituent concentrations were analyzed. Average concentrations of suspended sediment, settleable solids, and fecal coliform bacteria generally exceeded levels expected for secondary waste-treatment plant effluent, whereas biochemical oxygen demand concentrations were lower than expected. The second analytical approach established correlations and bivariate regression relationships between constituents for individual storms in each basin, for all storms in each basin, and for all storms in all basins. Generally, correlation coefficients decreased when progressing from data for individual storms in each basin, to data for all storms in each basin, to data for all storms in all basins. In the third approach, storm yields for 10 constituents were related to basin and precipitation characteristics by use of multiple-linear-regression techniques. Storm yields for suspended sediment varied by about four orders of magnitude. Generally, results of the multiple-regression analysis indicated that variations in storm yields were highly dependent on precipitation characteristics, with total rainfall of the storm frequently explaining most of the variation of the dependent variable.
NASA Astrophysics Data System (ADS)
Aylott, Benjamin; Baker, John G.; Boggs, William D.; Boyle, Michael; Brady, Patrick R.; Brown, Duncan A.; Brügmann, Bernd; Buchman, Luisa T.; Buonanno, Alessandra; Cadonati, Laura; Camp, Jordan; Campanelli, Manuela; Centrella, Joan; Chatterji, Shourov; Christensen, Nelson; Chu, Tony; Diener, Peter; Dorband, Nils; Etienne, Zachariah B.; Faber, Joshua; Fairhurst, Stephen; Farr, Benjamin; Fischetti, Sebastian; Guidi, Gianluca; Goggin, Lisa M.; Hannam, Mark; Herrmann, Frank; Hinder, Ian; Husa, Sascha; Kalogera, Vicky; Keppel, Drew; Kidder, Lawrence E.; Kelly, Bernard J.; Krishnan, Badri; Laguna, Pablo; Lousto, Carlos O.; Mandel, Ilya; Marronetti, Pedro; Matzner, Richard; McWilliams, Sean T.; Matthews, Keith D.; Mercer, R. Adam; Mohapatra, Satyanarayan R. P.; Mroué, Abdul H.; Nakano, Hiroyuki; Ochsner, Evan; Pan, Yi; Pekowsky, Larne; Pfeiffer, H. arald P.; Pollney, Denis; Pretorius, Frans; Raymond, Vivien; Reisswig, Christian; Rezzolla, Luciano; Rinne, Oliver; Robinson, Craig; Röver, Christian; Santamaría, Lucía; Sathyaprakash, Bangalore; Scheel, Mark A.; Schnetter, Erik; Seiler, Jennifer; Shapiro, Stuart L.; Shoemaker, Deirdre; Sperhake, Ulrich; Stroeer, Alexander; Sturani, Riccardo; Tichy, Wolfgang; Liu, Yuk Tung; van der Sluys, Marc; van Meter, James R.; Vaulin, Ruslan; Vecchio, Alberto; Veitch, John; Viceré, Andrea; Whelan, John T.; Zlochower, Yosef
2009-08-01
The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave data analysis communities. The purpose of NINJA is to study the sensitivity of existing gravitational-wave search algorithms using numerically generated waveforms and to foster closer collaboration between the numerical relativity and data analysis communities. We describe the results of the first NINJA analysis which focused on gravitational waveforms from binary black hole coalescence. Ten numerical relativity groups contributed numerical data which were used to generate a set of gravitational-wave signals. These signals were injected into a simulated data set, designed to mimic the response of the initial LIGO and Virgo gravitational-wave detectors. Nine groups analysed this data using search and parameter-estimation pipelines. Matched filter algorithms, un-modelled-burst searches and Bayesian parameter estimation and model-selection algorithms were applied to the data. We report the efficiency of these search methods in detecting the numerical waveforms and measuring their parameters. We describe preliminary comparisons between the different search methods and suggest improvements for future NINJA analyses.
Analysis and Numerical Treatment of Elliptic Equations with Stochastic Data
NASA Astrophysics Data System (ADS)
Cheng, Shi
Many science and engineering applications are impacted by a significant amount of uncertainty in the model. Examples include groundwater flow, microscopic biological system, material science and chemical engineering systems. Common mathematical problems in these applications are elliptic equations with stochastic data. In this dissertation, we examine two types of stochastic elliptic partial differential equations(SPDEs), namely nonlinear stochastic diffusion reaction equations and general linearized elastostatic problems in random media. We begin with the construction of an analysis framework for this class of SPDEs, extending prior work of Babuska in 2010. We then use the framework both for establishing well-posedness of the continuous problems and for posing Galerkintype numerical methods. In order to solve these two types of problems, single integral weak formulations and stochastic collocation methods are applied. Moreover, a priori error estimates for stochastic collocation methods are derived, which imply that the rate of convergence is exponential, along with the order of polynomial increasing in the space of random variables. As expected, numerical experiments show the exponential rate of convergence, verified by a posterior error analysis. Finally, an adaptive strategy driven by a posterior error indicators is designed.
Asymptotic and numerical analysis of electrohydrodynamic flows of dielectric liquid
NASA Astrophysics Data System (ADS)
Suh, Y. K.; Baek, K. H.; Cho, D. S.
2013-08-01
We perform an asymptotic analysis of electrohydrodynamic (EHD) flow of nonpolar liquid subjected to an external, nonuniform electric field. The domain of interest covers the bulk as well as the thin dissociation layers (DSLs) near the electrodes. Outer (i.e., bulk) equations for the ion transport in hierarchical order of perturbation parameters can be expressed in linear form, whereas the inner (i.e., DSL) equations take a nonlinear form. We derive a simple formula in terms of various parameters which can be used to estimate the relative importance of the DSL-driven flow compared with the bulk-driven flow. EHD flow over a pair of cylindrical electrodes is then solved asymptotically and numerically. It is found that in large geometric scale and high ion concentration the EHD flow is dominated by the bulk-charge-induced flow. As the scale and concentration are decreased, the DSL-driven slip velocity increases and the resultant flow tends to dominate the domain and finally leads to flow reversal. We also conduct a flow-visualization experiment to verify the analysis and attain good agreement between the two results with parameter tuning. We finally show, based on the comparison of experimental and numerical solutions, that the rate of free-ion generation (dissociation) should be less than the one predicted from the existing formula.
105-N basin sediment disposition phase-two sampling and analysis plan
Smith, R. C.
1997-03-14
The sampling and analysis plan for Phase 2 of the 105-N Basin sediment disposition task defines the sampling and analytical activities that will be performed to support characterization of the sediment and selection of an appropriate sediment disposal option.
Direct numerical simulation and analysis of shock turbulence interaction
NASA Technical Reports Server (NTRS)
Lee, Sangsan; Lele, Sanjiva K.; Moin, Parviz
1991-01-01
Two kinds of linear analysis, rapid distortion theory (RDT) and linear interaction analysis (LIA), were used to investigate the effects of a shock wave on turbulence. Direct numerical simulations of two-dimensional isotropic turbulence interaction with a normal shock were also performed. The results from RDT and LIA are in good agreement for weak shock waves, where the effects of shock front curvature and shock front unsteadiness are not significant in producing vorticity. The linear analyses predict wavenumber-dependent amplification of the upstream one-dimensional energy spectrum, leading to turbulence scale length scale decrease through the interaction. Instantaneous vorticity fields show that vortical structures are enhanced while they are compressed in the shock normal direction. Entrophy amplfication through the shock wave compares favorably with the results of linear analyses.
NASA Astrophysics Data System (ADS)
Tepe, Çiǧdem; Sözbilir, Hasan
2016-04-01
The purpose of this study is to discuss the geological and geomorphological features of active faults controlling Kemalpaşa Basin. The study consists of basin-bounding faults expressions, kinematic and geomorphic analysis. Kemalpaşa Basin, which is approximately ENE trending and asymmetric graben is located in the southern part of Gediz Graben. Menderes Massif and Bornova Complex comprise the basement rocks of basin. Kızılca Formation, Sütçüler Formation and Alluvium uncomformably overlie the basement rocks. Kemalpaşa Basin which is one of the Quaternary basin in the Western Anatolia Extensional Province was developed at the structural border of the Spildaǧı Fault Zone in the north and the Kemalpaşa Fault in the south. Both the north and south margin-bounding faults of Kemalpaşa Basin are oblique-slip normal faults. According to the results of kinematic analysis, Kemalpaşa Basin has been formed under a NE-GW trending extensional tectonic regime. The variation in the relative degree of tectonic activity in Kemalpaşa Basin and its surroundings were interpreted a detailed geomorphic study of the fault-generated mountain fronts and drainage pattern of the both sides. To identify the impacts of active faults controlling the north and south margins of Kemalpaşa Basin on the geomorphological evolution, the geomorphic indices such as drainage basin geometries, triangular facets, axial river profiles have been determined and the degree of tectonic activity in the both sides of Kemalpaşa Basin has been numerically defined using morphometric indexes such as asymmetry factor (AF), hypsometric curve and integral (HI), valley floor width-to-height ratio (Vf) and mountain front sinuosity (Smf). In morphometric analysis, the both sides of the basin were investigated separating into two segments as the west and east. The values of HI (0,28-0,60), Vf (0,27-0,60) and Smf (1,3) calculated for the western part of the north margin compared with the values of HI (0
NASA Astrophysics Data System (ADS)
Bateman, A.; Medina, V.; Hürlimann, M.
2009-04-01
Debris flows are present in every country where a combination of high mountains and flash floods exists. In the northern part of the Iberian Peninsula, at the Pyrenees, sporadic debris events occur. We selected two different events. The first one was triggered at La Guingueta by the big exceptional flood event that produced many debris flows in 1982 which were spread all over the Catalonian Pyrenees. The second, more local event occurred in 2000 at the mountain Montserrat at the Pre-litoral mountain chain. We present here some results of the FLATModel, entirely developed at the Research Group in Sediment Transport of the Hydraulic, Marine and Environmental Engineering Department (GITS-UPC). The 2D FLATModel is a Finite Volume method that uses the Godunov scheme. Some numerical arranges have been made to analyze the entrainment process during the events, the Stop & Go phenomena and the final deposit of the material. The material rheology implemented is the Voellmy approach, because it acts very well evaluating the frictional and turbulent behavior. The FLATModel uses a GIS environment that facilitates the data analysis as the comparison between field and numerical data. The two events present two different characteristics, one is practically a one dimensional problem of 1400 m in length and the other has a more two dimensional behavior that forms a big fan.
Buker, C.; Littke, R.; Welte, D.H.
1995-08-01
The detailed and reliable reconstruction of the geological and thermal evolution of sedimentary basins forms the indispensable basis of any simulation of generation, migration and accumulation of hydrocarbons. For this purpose - although often not taken into account - analysing and quantifying the uplift and erosion history is as important as the subsidence and temperature history. The reconstruction of the timing of hydrocarbon generation, petroleum expulsion and migration and the changing reservoir characteristics is only possible based on such an integrated approach. Applying this technique on the Carboniferous Ruhr Basin and the Lower Saxony Basin (western Germany) by utilising 1-D and 2-D forward modeling approaches resulted in important and new quantitative information on their temperature, subsidence and erosion histories which are of fundamental geological interest. The basin evolution models were calibrated using vitrinite reflectance data, fluid inclusion temperatures, and apatite and zircon fission track data. The detailed knowledge of the geological and thermal basin evolution then allowed in combination with a new kinetic model for gas generation from coals the modeling of generation, migration and accumulation of methane from Carboniferous coal seams.
Numerical analysis of modified Central Solenoid insert design
Khodak, Andrei; Martovetsky, Nicolai; Smirnov, Aleksandre; Titus, Peter
2015-06-21
The United States ITER Project Office (USIPO) is responsible for fabrication of the Central Solenoid (CS) for ITER project. The ITER machine is currently under construction by seven parties in Cadarache, France. The CS Insert (CSI) project should provide a verification of the conductor performance in relevant conditions of temperature, field, currents and mechanical strain. The US IPO designed the CSI that will be tested at the Central Solenoid Model Coil (CSMC) Test Facility at JAEA, Naka. To validate the modified design we performed three-dimensional numerical simulations using coupled solver for simultaneous structural, thermal and electromagnetic analysis. Thermal and electromagnetic simulations supported structural calculations providing necessary loads and strains. According to current analysis design of the modified coil satisfies ITER magnet structural design criteria for the following conditions: (1) room temperature, no current, (2) temperature 4K, no current, (3) temperature 4K, current 60 kA direct charge, and (4) temperature 4K, current 60 kA reverse charge. Fatigue life assessment analysis is performed for the alternating conditions of: temperature 4K, no current, and temperature 4K, current 45 kA direct charge. Results of fatigue analysis show that parts of the coil assembly can be qualified for up to 1 million cycles. Distributions of the Current Sharing Temperature (TCS) in the superconductor were obtained from numerical results using parameterization of the critical surface in the form similar to that proposed for ITER. Lastly, special ADPL scripts were developed for ANSYS allowing one-dimensional representation of TCS along the cable, as well as three-dimensional fields of TCS in superconductor material. Published by Elsevier B.V.
Numerical analysis of modified Central Solenoid insert design
Khodak, Andrei; Martovetsky, Nicolai; Smirnov, Aleksandre; ...
2015-06-21
The United States ITER Project Office (USIPO) is responsible for fabrication of the Central Solenoid (CS) for ITER project. The ITER machine is currently under construction by seven parties in Cadarache, France. The CS Insert (CSI) project should provide a verification of the conductor performance in relevant conditions of temperature, field, currents and mechanical strain. The US IPO designed the CSI that will be tested at the Central Solenoid Model Coil (CSMC) Test Facility at JAEA, Naka. To validate the modified design we performed three-dimensional numerical simulations using coupled solver for simultaneous structural, thermal and electromagnetic analysis. Thermal and electromagneticmore » simulations supported structural calculations providing necessary loads and strains. According to current analysis design of the modified coil satisfies ITER magnet structural design criteria for the following conditions: (1) room temperature, no current, (2) temperature 4K, no current, (3) temperature 4K, current 60 kA direct charge, and (4) temperature 4K, current 60 kA reverse charge. Fatigue life assessment analysis is performed for the alternating conditions of: temperature 4K, no current, and temperature 4K, current 45 kA direct charge. Results of fatigue analysis show that parts of the coil assembly can be qualified for up to 1 million cycles. Distributions of the Current Sharing Temperature (TCS) in the superconductor were obtained from numerical results using parameterization of the critical surface in the form similar to that proposed for ITER. Lastly, special ADPL scripts were developed for ANSYS allowing one-dimensional representation of TCS along the cable, as well as three-dimensional fields of TCS in superconductor material. Published by Elsevier B.V.« less
2014-07-01
Barrier Shoreline Wetland Value Assessment Model1 by S. Kyle McKay2 and J. Craig Fischenich3 OVERVIEW: Sensitivity analysis is a technique for...scale restoration projects to reduce marsh loss and maintain these wetlands as healthy functioning ecosystems. The Barataria Basin Barrier Shoreline...Sensitivity Analysis of the Barataria Basin Barrier Shoreline Wetland Value Assessment Model1 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT
Xu, Hua-Shan; Xu, Zong-Xue; Tang, Fang-Fang; Yu, Wei-Dong; Cheng, Yan-Ping
2012-02-01
In this study, several statistical methods including cluster analysis, seasonal Kendall test, factor analysis/principal component analysis and principal component regression were used to evaluate the spatiotemporal variation of water quality and identify the sources of water pollution in the Zhangweinan River basin. Results of spatial cluster analysis and principal component analysis indicated that the Zhangweinan River basin can be classified into two regions. One is the Zhang River upstream located in the northwest of the Zhangweinan River basin where water quality is good. The other one covers the Wei River and eastern plain of the Zhangweinan River basin, where water is seriously polluted. In this region, pollutants from point sources flow into the river and the water quality changes greatly. Results of temporal cluster analysis and seasonal Kendall test indicated that the study periods may be classified into three periods and two different trends were detected during the period of 2002-2009. The first period was the year of 2002-2003, during which water quality had deteriorated and serious pollution was observed in the Wei river basin and eastern plain of the Zhangweinan River basin. The second period was the year of 2004-2006, during which water quality became better. The year of 2007-2009 is the third period, during which water quality had been improved greatly. Despite that water quality in the Zhangweinan River basin had been improved during the period of 2004-2009, the water quality in the Wei River (southwestern part of the basin), the Wei Canal River and the Zhangweixin River (eastern plain of the basin) is still poor. Principal component analysis and multi-linear regression of the absolute principal component scores showed that the main pollutants of the Zhangweinan River basin came from point source discharge such as heavy industrial wastewater, municipal sewage, chemical industries wasterwater and mine drainage in upstream. Non-point source pollution
A GIS-based approach in drainage morphometric analysis of Kanhar River Basin, India
NASA Astrophysics Data System (ADS)
Rai, Praveen Kumar; Mohan, Kshitij; Mishra, Sameer; Ahmad, Aariz; Mishra, Varun Narayan
2017-03-01
The study indicates that analysis of morphometric parameters with the help of geographic information system (GIS) would prove a viable method of characterizing the hydrological response behaviour of the watershed. It is also well observed that remote sensing satellite data is emerging as the most effective, time saving and accurate technique for morphometric analysis of a basin. This technique is found relevant for the extraction of river basin and its stream networks through ASTER (DEM) in conjunction with remote sensing satellite data (Landsat etm+, 2013 and georeferenced survey of Indian toposheet, 1972). In this study, Kanhar basin a tributaries of Son River has been selected for detailed morphometric analysis. Seven sub-watersheds are also delineated within this basin to calculate the selected morphometric parameters. Morphometric parameters viz; stream order, stream length, bifurcation ratio, drainage density, stream frequency, form factor, circulatory ratio, etc., are calculated. The drainage area of the basin is 5,654 km2 and shows sub-dendritic to dendritic drainage pattern. The stream order of the basin is mainly controlled by physiographic and lithological conditions of the area. The study area is designated as seventh-order basin with the drainage density value being as 1.72 km/km2. The increase in stream length ratio from lower to higher order shows that the study area has reached a mature geomorphic stage.
Arnold, L.R.
2010-01-01
The Lost Creek Designated Ground Water Basin (Lost Creek basin) is an important alluvial aquifer for irrigation, public supply, and domestic water uses in northeastern Colorado. Beginning in 2005, the U.S. Geological Survey, in cooperation with the Lost Creek Ground Water Management District and the Colorado Water Conservation Board, collected hydrologic data and constructed a steady-state numerical groundwater flow model of the Lost Creek basin. The model builds upon the work of previous investigators to provide an updated tool for simulating the potential effects of various hydrologic stresses on groundwater flow and evaluating possible aquifer-management strategies. As part of model development, the thickness and extent of regolith sediments in the basin were mapped, and data were collected concerning aquifer recharge beneath native grassland, nonirrigated agricultural fields, irrigated agricultural fields, and ephemeral stream channels. The thickness and extent of regolith in the Lost Creek basin indicate the presence of a 2- to 7-mile-wide buried paleovalley that extends along the Lost Creek basin from south to north, where it joins the alluvial valley of the South Platte River valley. Regolith that fills the paleovalley is as much as about 190 ft thick. Average annual recharge from infiltration of precipitation on native grassland and nonirrigated agricultural fields was estimated by using the chloride mass-balance method to range from 0.1 to 0.6 inch, which represents about 1-4 percent of long-term average precipitation. Average annual recharge from infiltration of ephemeral streamflow was estimated by using apparent downward velocities of chloride peaks to range from 5.7 to 8.2 inches. Average annual recharge beneath irrigated agricultural fields was estimated by using passive-wick lysimeters and a water-balance approach to range from 0 to 11.3 inches, depending on irrigation method, soil type, crop type, and the net quantity of irrigation water applied
Putnam, P.E.; Moore, S. ); Ward, G. )
1990-05-01
Linking hydrodynamics to detailed stratigraphic and structural analyses is a powerful tool in hydrocarbon exploration in mature basins, In southernmost Canada straddling the Alberta-Saskatchewan border, significant petroleum reserves are encountered within Mesozoic units which are largely controlled by subsurface flow cells. The Jurassic Sawtooth Formation is characterized by an eastward shift from lower shoreface quartzarenites to basinal coquinas. The Sawtooth is a blanket deposit and crops out along the flanks of several Tertiary uplifts in northern Montana. In the subsurface the Sawtooth is draped over several relatively young structures. Potentiometric mapping illustrates a northerly flow orientation within the Sawtooth, and oil pools under artesian conditions are located where flow paths cross steeply flanked structures. The Lower Cretaceous Sunburst Formation is a series of valley-fill sandstones with mainly southwesterly paleoflow orientations. Hydrocarbon pools (e.g., Manyberries field) are located within a regional potentiometric low formed by three converging cells which recharge in the south, northwest, and east. This potentiometric low is characterized by systematic changes in oil and water compositions, with progressively lighter oils and NaCl-rich waters found toward the low's center. Stratigraphic variability controls pooling within the low, with hydrocarbons located on the updip flanks of valley fills which border nonreservoir rocks. In the northwestern Williston basin regional hydrodynamic analysis, combined with standard subsurface approaches, allows operators to discern large new hydrocarbon-bearing trends within and between densely drilled areas characterized by complex structure and stratigraphy.
Numerical Analysis of Film Cooling at High Blowing Ratio
NASA Technical Reports Server (NTRS)
El-Gabry, Lamyaa; Heidmann, James; Ameri, Ali
2009-01-01
Computational Fluid Dynamics is used in the analysis of a film cooling jet in crossflow. Predictions of film effectiveness are compared with experimental results for a circular jet at blowing ratios ranging from 0.5 to 2.0. Film effectiveness is a surface quantity which alone is insufficient in understanding the source and finding a remedy for shortcomings of the numerical model. Therefore, in addition, comparisons are made to flow field measurements of temperature along the jet centerline. These comparisons show that the CFD model is accurately predicting the extent and trajectory of the film cooling jet; however, there is a lack of agreement in the near-wall region downstream of the film hole. The effects of main stream turbulence conditions, boundary layer thickness, turbulence modeling, and numerical artificial dissipation are evaluated and found to have an insufficient impact in the wake region of separated films (i.e. cannot account for the discrepancy between measured and predicted centerline fluid temperatures). Analyses of low and moderate blowing ratio cases are carried out and results are in good agreement with data.
Numerical model of solar dynamic radiator for parametric analysis
NASA Technical Reports Server (NTRS)
Rhatigan, Jennifer L.
1989-01-01
Growth power requirements for Space Station Freedom will be met through addition of 25 kW solar dynamic (SD) power modules. The SD module rejects waste heat from the power conversion cycle to space through a pumped-loop, multi-panel, deployable radiator. The baseline radiator configuration was defined during the Space Station conceptual design phase and is a function of the state point and heat rejection requirements of the power conversion unit. Requirements determined by the overall station design such as mass, system redundancy, micrometeoroid and space debris impact survivability, launch packaging, costs, and thermal and structural interaction with other station components have also been design drivers for the radiator configuration. Extensive thermal and power cycle modeling capabilities have been developed which are powerful tools in Station design and analysis, but which prove cumbersome and costly for simple component preliminary design studies. In order to aid in refining the SD radiator to the mature design stage, a simple and flexible numerical model was developed. The model simulates heat transfer and fluid flow performance of the radiator and calculates area mass and impact survivability for many combinations of flow tube and panel configurations, fluid and material properties, and environmental and cycle variations. A brief description and discussion of the numerical model, it's capabilities and limitations, and results of the parametric studies performed is presented.
Mukhopadhyay, Sumit; Spycher, Nicolas; Pester, Nick; Saldi, Giuseppe; Beyer, John; Houseworth, Jim; Knauss, Kevin
2014-09-04
This report presents findings for hydrological and chemical characteristics and processes relevant to large-scale geologic CO_{2} sequestration in the Newark Basin of southern New York and northern New Jersey. This work has been conducted in collaboration with the Tri-Carb Consortium for Carbon Sequestration — comprising Sandia Technologies, LLC; Conrad Geoscience; and Schlumberger Carbon Services.
Preliminary Numerical and Experimental Analysis of the Spallation Phenomenon
NASA Technical Reports Server (NTRS)
Martin, Alexandre; Bailey, Sean C. C.; Panerai, Francesco; Davuluri, Raghava S. C.; Vazsonyi, Alexander R.; Zhang, Huaibao; Lippay, Zachary S.; Mansour, Nagi N.; Inman, Jennifer A.; Bathel, Brett F.; Splinter, Scott C.; Danehy, Paul M.
2015-01-01
The spallation phenomenon was studied through numerical analysis using a coupled Lagrangian particle tracking code and a hypersonic aerothermodynamics computational fluid dynamics solver. The results show that carbon emission from spalled particles results in a significant modification of the gas composition of the post shock layer. Preliminary results from a test-campaign at the NASA Langley HYMETS facility are presented. Using an automated image processing of high-speed images, two-dimensional velocity vectors of the spalled particles were calculated. In a 30 second test at 100 W/cm2 of cold-wall heat-flux, more than 1300 particles were detected, with an average velocity of 102 m/s, and most frequent observed velocity of 60 m/s.
A Cartesian parametrization for the numerical analysis of material instability
Mota, Alejandro; Chen, Qiushi; Foulk, III, James W.; ...
2016-02-25
We examine four parametrizations of the unit sphere in the context of material stability analysis by means of the singularity of the acoustic tensor. We then propose a Cartesian parametrization for vectors that lie a cube of side length two and use these vectors in lieu of unit normals to test for the loss of the ellipticity condition. This parametrization is then used to construct a tensor akin to the acoustic tensor. It is shown that both of these tensors become singular at the same time and in the same planes in the presence of a material instability. Furthermore, themore » performance of the Cartesian parametrization is compared against the other parametrizations, with the results of these comparisons showing that in general, the Cartesian parametrization is more robust and more numerically efficient than the others.« less
Asymptotic analysis of numerical wave propagation in finite difference equations
NASA Technical Reports Server (NTRS)
Giles, M.; Thompkins, W. T., Jr.
1983-01-01
An asymptotic technique is developed for analyzing the propagation and dissipation of wave-like solutions to finite difference equations. It is shown that for each fixed complex frequency there are usually several wave solutions with different wavenumbers and the slowly varying amplitude of each satisfies an asymptotic amplitude equation which includes the effects of smoothly varying coefficients in the finite difference equations. The local group velocity appears in this equation as the velocity of convection of the amplitude. Asymptotic boundary conditions coupling the amplitudes of the different wave solutions are also derived. A wavepacket theory is developed which predicts the motion, and interaction at boundaries, of wavepackets, wave-like disturbances of finite length. Comparison with numerical experiments demonstrates the success and limitations of the theory. Finally an asymptotic global stability analysis is developed.
Numerical Analysis of a Finite Element/Volume Penalty Method
NASA Astrophysics Data System (ADS)
Maury, Bertrand
The penalty method makes it possible to incorporate a large class of constraints in general purpose Finite Element solvers like freeFEM++. We present here some contributions to the numerical analysis of this method. We propose an abstract framework for this approach, together with some general error estimates based on the discretization parameter ɛ and the space discretization parameter h. As this work is motivated by the possibility to handle constraints like rigid motion for fluid-particle flows, we shall pay a special attention to a model problem of this kind, where the constraint is prescribed over a subdomain. We show how the abstract estimate can be applied to this situation, in the case where a non-body-fitted mesh is used. In addition, we describe how this method provides an approximation of the Lagrange multiplier associated to the constraint.
Measurement and numerical analysis of flammability limits of halogenated hydrocarbons.
Kondo, Shigeo; Takizawa, Kenji; Takahashi, Akifumi; Tokuhashi, Kazuaki
2004-06-18
Flammability limits measurement was made for a number of halogenated compounds by the ASHRAE method. Most of compounds measured are the ones for which discrepancy was noted between the literature values and predicted values of flammability limits. As a result, it has been found that most of the newly obtained values of flammability limits are not in accordance with the literature values. Numerical analysis was carried out for a set of flammability limits data including the newly obtained ones using a modified analytical method based on F-number scheme. In this method, fitting procedure was done directly to flammability limits themselves instead of fitting to F-number. After the fitting process, the average relative deviation between the observed and calculated values is 9.3% for the lower limits and 14.6% for the upper limits.
A Cartesian parametrization for the numerical analysis of material instability
Mota, Alejandro; Chen, Qiushi; Foulk, III, James W.; Ostien, Jakob T.; Lai, Zhengshou
2016-02-25
We examine four parametrizations of the unit sphere in the context of material stability analysis by means of the singularity of the acoustic tensor. We then propose a Cartesian parametrization for vectors that lie a cube of side length two and use these vectors in lieu of unit normals to test for the loss of the ellipticity condition. This parametrization is then used to construct a tensor akin to the acoustic tensor. It is shown that both of these tensors become singular at the same time and in the same planes in the presence of a material instability. Furthermore, the performance of the Cartesian parametrization is compared against the other parametrizations, with the results of these comparisons showing that in general, the Cartesian parametrization is more robust and more numerically efficient than the others.
Numerical analysis of the dynamics of distributed vortex configurations
NASA Astrophysics Data System (ADS)
Govorukhin, V. N.
2016-08-01
A numerical algorithm is proposed for analyzing the dynamics of distributed plane vortex configurations in an inviscid incompressible fluid. At every time step, the algorithm involves the computation of unsteady vortex flows, an analysis of the configuration structure with the help of heuristic criteria, the visualization of the distribution of marked particles and vorticity, the construction of streamlines of fluid particles, and the computation of the field of local Lyapunov exponents. The inviscid incompressible fluid dynamic equations are solved by applying a meshless vortex method. The algorithm is used to investigate the interaction of two and three identical distributed vortices with various initial positions in the flow region with and without the Coriolis force.
Experimental and Numerical Analysis of Notched Composites Under Tension Loading
NASA Astrophysics Data System (ADS)
Aidi, Bilel; Case, Scott W.
2015-12-01
Experimental quasi-static tests were performed on center notched carbon fiber reinforced polymer (CFRP) composites having different stacking sequences made of G40-600/5245C prepreg. The three-dimensional Digital Image Correlation (DIC) technique was used during quasi-static tests conducted on quasi-isotropic notched samples to obtain the distribution of strains as a function of applied stress. A finite element model was built within Abaqus to predict the notched strength and the strain profiles for comparison with measured results. A user-material subroutine using the multi-continuum theory (MCT) as a failure initiation criterion and an energy-based damage evolution law as implemented by Autodesk Simulation Composite Analysis (ASCA) was used to conduct a quantitative comparison of strain components predicted by the analysis and obtained in the experiments. Good agreement between experimental data and numerical analyses results are observed. Modal analysis was carried out to investigate the effect of static damage on the dominant frequencies of the notched structure using the resulted degraded material elements. The first in-plane mode was found to be a good candidate for tracking the level of damage.
A Structural Analysis of the Lewiston Basin, Clarkston, WA
NASA Astrophysics Data System (ADS)
Alloway, M.; Watkinson, A.; Reidel, S. P.
2010-12-01
The Lewiston Structure is located in southeastern Washington / west-central Idaho and is a generally E-W trending asymmetric, non-cylindrical anticline in the Columbia River Basalt Group (CRBG) that transfers displacement into the Limekiln fault system to the southeast. A serial cross-section analysis and 3-D construction of this structure shows how the fold varies along its trend and sheds light on the deformational history of the Lewiston Basin. Construction of the fold’s 3-D form shows that the fold’s wavelength increases and amplitude decreases eastward along its trend. Balanced cross-sections show approximately 5% shortening across the structure which is consistent with the Yakima Fold Belt (YFB). Although the structure is similar to the YFB, it does not form part of a belt and its local nature has been suggested to mark the cratonic boundary of the Cretaceous. Discovery of an angular unconformity in the Grande Ronde Basalt - reverse polarity unit 1 (GRB-R1) proves that the NE trending section of the fold was deforming during emplacement of R1 and allows separation of the fold into two structural domains. Analysis of the two domains using the Gauss method for heterogeneous fault-slip data indicate NW-SE shortening during R1 time and N-S shortening for post CRBG emplacement. Furthermore, slip data for strain-inversion and specification of spatial-distribution patterns help identify the existence of a transpressional tectonic environment. The nature of faulting associated with the Lewiston Structure is a topic of some debate, namely the presence of a reverse fault on the southern limb of the fold conspicuously hidden by the Snake River. The reverse fault under debate outcrops to the east of the field area and is GRB-R2 (reverse polarity unit 2) thrust over Pliocene gravels. Better control on unit thicknesses and map contacts rule out the possibility of a reverse fault exposed on the surface of the southern limb of the fold in the field area. This major fault
NASA Astrophysics Data System (ADS)
Chaljub, Emmanuel; Maufroy, Emeline; Moczo, Peter; Kristek, Jozef; Priolo, Enrico; Klin, Peter; De Martin, Florent; Zhang, Zenghuo; Hollender, Fabrice; Bard, Pierre-Yves
2013-04-01
Numerical simulation is playing a role of increasing importance in the field of seismic hazard by providing quantitative estimates of earthquake ground motion, its variability, and its sensitivity to geometrical and mechanical properties of the medium. Continuous efforts to develop accurate and computationally efficient numerical methods, combined with increasing computational power have made it technically feasible to calculate seismograms in 3D realistic configurations and for frequencies of interest in seismic design applications. Now, in order to foster the use of numerical simulations in practical prediction of earthquake ground motion, it is important to evaluate the accuracy of current numerical methods when applied to realistic 3D sites. This process of verification is a necessary prerequisite to confrontation of numerical predictions and observations. Through the ongoing Euroseistest Verification and Validation Project (E2VP), which focuses on the Mygdonian basin (northern Greece), we investigated the capability of numerical methods to predict earthquake ground motion for frequencies up to 4 Hz. Numerical predictions obtained by several teams using a wide variety of methods were compared using quantitative goodness-of-fit criteria. In order to better understand the cause of misfits between different simulations, initially performed for the realistic geometry of the Mygdonian basin, we defined five stringent canonical configurations. The canonical models allow for identifying sources of misfits and quantify their importance. Detailed quantitative comparison of simulations in relation to dominant features of the models shows that even relatively simple heterogeneous models must be treated with maximum care in order to achieve sufficient level of accuracy. One important conclusion is that the numerical representation of models with strong variations (e.g. discontinuities) may considerably vary from one method to the other, and may become a dominant source of
Preliminary Hazards Analysis of K-Basin Fuel Encapsulation and Storage
Strickland, G.C.
1994-08-19
This Preliminary Hazards Analysis (PHA) systematically examines the K-Basin facilities and their supporting systems for hazards created by abnormal operating conditions and external events (e.g., earthquakes) which have the potential for causing undesirable consequences to the facility worker, the onsite individual, or the public. The operational activities examined are fuel encapsulation, fuel storage and cooling. Encapsulation of sludges in the basins is not examined. A team of individuals from Westinghouse produced a set of Hazards and Operability (HAZOP) tables documenting their examination of abnormal process conditions in the systems and activities examined in K-Basins. The purpose of this report is to reevaluate and update the HAZOP in the original Preliminary Hazard Analysis of K-Basin Fuel Encapsulation and Storage originally developed in 1991.
Water quality analysis of Godavari river basin using multivariate analysis techniques.
Gupta, Indrani; Salunkhe, Abhaysinh; Rohra, Nanda; Kumar, Rakesh
2013-01-01
Multivariate statistical techniques, including cluster analysis, principal component analysis factor analysis and discriminant analysis, have been used to evaluate spatial variations and to interpret a large and complex water quality data set collected from the Godavari river basin. The data sets, containing 7 parameters, were generated during the 3-years (2007-2009) at 78 different sites along the river and its tributaries. Water quality indices based on four parameters (pH, DO, BOD and FC) calculated for all the sites were found to be medium to good, good to excellent and bad using modified NSF index. Three significant groups (cleaner, slightly and moderately polluted sites) were detected by CA method, and three latent factors were identified by PCA method. The results of DA revealed that only two parameters (i.e. pH and BOD) were necessary for analysis in spatial variation. 83.3% of the original sites were correctly.classified using discriminant function developed from the analysis.
A REGIONAL ECOLOGICAL ANALYSIS OF THE GREAT LAKES BASIN
The U.S. Environmental Protection Agency (EPA) and Natural Resources Canada: Canada Centre for Remote Sensing (CCRS) are conducting a cooperative research landscape ecological study of the Great Lakes Basin. The analyses will include the areas located along the border of the Unit...
A LANDSCAPE ECOLOGY ANALYSIS OF THE GREAT LAKES BASIN
The U.S. Environmental Protection Agency (EPA) and Natural Resources Canada: Canada Centre for Remote Sensing (CCRS) are conducting a cooperative research landscape ecological study of the Great Lakes Basin. The analyses will include the areas located along the border of the Unit...
A LANDSCAPE ECOLOGY ANALYSIS OF THE GREAT LAKES BASIN
The U.S. Environmental Protection Agency (EPA) and Natural Resources Canada: Canada Centre for Remote Sensing (CCRS) are conducting a cooperative research landscape ecological study of the Great Lakes Basin. The analyses will include the areas located along the border of the Unit...
ALEXI analysis of water consumption in the Nile Basin
USDA-ARS?s Scientific Manuscript database
Remote sensing can be used to generate diagnostic estimates of evapotranspiration (ET) that provide information regarding consumptive water use across landscapes. These satellite-based assessments can be a valuable complement to prognostic simulations of basin-scale water budgets, providing an inde...
A REGIONAL ECOLOGICAL ANALYSIS OF THE GREAT LAKES BASIN
The U.S. Environmental Protection Agency (EPA) and Natural Resources Canada: Canada Centre for Remote Sensing (CCRS) are conducting a cooperative research landscape ecological study of the Great Lakes Basin. The analyses will include the areas located along the border of the Unit...
An analysis of the carbon balance of the Arctic Basin from 1997 to 2006
A.D. McGuire; D.J. Hayes; D.W. Kicklighter; M. Manizza; Q. Zhuang; M. Chen; M.J. Follows; K.R. Gurney; J.W. McClelland; J.M. Melillo; B.J. Peterson; R.G. Prinn
2010-01-01
This study used several model-based tools to analyze the dynamics of the Arctic Basin between 1997 and 2006 as a linked system of land-ocean-atmosphere C exchange. The analysis estimates that terrestrial areas of the Arctic Basin lost 62.9 Tg C yr-1 and that the Arctic Ocean gained 94.1 Tg C yr-1. Arctic lands and oceans...
1981-10-01
BASIN LARIMER-WELD COUNTIES COLORADO VOLUME I FLOOD HAZARD, DAM SAFETY, AND FLOOD WARNING VOLUME II HYDROLOGY VOLUME III FLOOD PLAIN ANALYSIS, SHEEP...presented in four separate volumes. Vol- ume I considers basin flood hazards, dam safety, and flood warning. Volume II presents the detailed...has its source near the south end of Horsetooth Reservoir and flows in a generally eastward direction to its confluence with the Cache la Poudre
NASA Astrophysics Data System (ADS)
Nakayama, K.; Maruya, Y.; Matsumoto, K.; Komata, M.; Komai, K.; Kuwae, T.
2015-11-01
Total nitrogen (TN), which consists of total particulate nitrogen (TPN) and total dissolved nitrogen (TDN), is transported with not only in river channels but also across the entire river basin, including via ground water and migratory animals. In general, TPN export from an entire river basin to the ocean is larger than TDN in a mountainous region. Since marine derived nutrients (MDN) are hypothesized to be mainly transported as suspended matters from the ground surface, it is necessary to investigate the contribution of MDN to the forest floor (soils) in order to quantify the true role of MDN at the river ecosystem scale. This study investigated TN export from an entire river basin, and also we estimated the contribution of pink (Oncorhynchus gorbuscha) and chum salmon (O. keta) to total oceanic nitrogen input across a river basin. The maximum potential contribution of TN entering the river basin by salmon was found to be 23.8 % relative to the total amount of TN exported from the river basin. The contribution of particulate nitrogen based on suspended sediment from the ocean to the river basin soils was 22.9 % with SD of 3.6 % by using stable isotope analysis (SIA) of nitrogen (δ15N).
A stable and efficient numerical algorithm for unconfined aquifer analysis.
Keating, Elizabeth; Zyvoloski, George
2009-01-01
The nonlinearity of equations governing flow in unconfined aquifers poses challenges for numerical models, particularly in field-scale applications. Existing methods are often unstable, do not converge, or require extremely fine grids and small time steps. Standard modeling procedures such as automated model calibration and Monte Carlo uncertainty analysis typically require thousands of model runs. Stable and efficient model performance is essential to these analyses. We propose a new method that offers improvements in stability and efficiency and is relatively tolerant of coarse grids. It applies a strategy similar to that in the MODFLOW code to the solution of Richard's equation with a grid-dependent pressure/saturation relationship. The method imposes a contrast between horizontal and vertical permeability in gridblocks containing the water table, does not require "dry" cells to convert to inactive cells, and allows recharge to flow through relatively dry cells to the water table. We establish the accuracy of the method by comparison to an analytical solution for radial flow to a well in an unconfined aquifer with delayed yield. Using a suite of test problems, we demonstrate the efficiencies gained in speed and accuracy over two-phase simulations, and improved stability when compared to MODFLOW. The advantages for applications to transient unconfined aquifer analysis are clearly demonstrated by our examples. We also demonstrate applicability to mixed vadose zone/saturated zone applications, including transport, and find that the method shows great promise for these types of problem as well.
A stable and efficient numerical algorithm for unconfined aquifer analysis
Keating, Elizabeth; Zyvoloski, George
2008-01-01
The non-linearity of equations governing flow in unconfined aquifers poses challenges for numerical models, particularly in field-scale applications. Existing methods are often unstable, do not converge, or require extremely fine grids and small time steps. Standard modeling procedures such as automated model calibration and Monte Carlo uncertainty analysis typically require thousands of forward model runs. Stable and efficient model performance is essential to these analyses. We propose a new method that offers improvements in stability and efficiency, and is relatively tolerant of coarse grids. It applies a strategy similar to that in the MODFLOW code to solution of Richard's Equation with a grid-dependent pressure/saturation relationship. The method imposes a contrast between horizontal and vertical permeability in gridblocks containing the water table. We establish the accuracy of the method by comparison to an analytical solution for radial flow to a well in an unconfined aquifer with delayed yield. Using a suite of test problems, we demonstrate the efficiencies gained in speed and accuracy over two-phase simulations, and improved stability when compared to MODFLOW. The advantages for applications to transient unconfined aquifer analysis are clearly demonstrated by our examples. We also demonstrate applicability to mixed vadose zone/saturated zone applications, including transport, and find that the method shows great promise for these types of problem, as well.
NASA Astrophysics Data System (ADS)
Mohamed, R. A. M.; Jones, S. B.; Neale, C. M. U.
2016-12-01
Long-term monitoring of ground surface temperature and heat flow near hydrothermally active areas in Yellowstone National Park can help determine possible changes of the subsurface heat flow. Some of these changes may alter the safety of the park's visitors, rangers and scientists. The geothermal heated ground in Norris Geyser Basin in Yellowstone National Park receives heat from both the geothermal gradient and the atmospheric shortwave and longwave radiations. In this study a one dimensional numerical model was used to model the coupled movement of liquid water, water vapor, and heat in the top 10 cm soil layer near a hydrothermal crater in Norris Geyser Basin. The Hydrus 1D numerical model was used to simulate the coupled processes in order to optimize the soil hydraulic parameters. Parameter optimization was done using Marquardt-Levenberg type parameter optimization algorithm for variably saturated soil under steady state and transient flow conditions. The simulation of coupled heat transport and liquid water and water vapor flow in geothermally heated ground is a new application to Hydrus 1D. Preliminary results, however, showed that the calculated temperature and water content correlated well with observed patterns on both dry sunny days and wet days. The study explained the coupled processes at the ground-atmosphere boundary layer which can help determine possible changes within the subsurface heat flow from the geothermal source.
Trace fossil analysis of lacustrine facies and basins
Buatois, L.A.; Mangano, M.G.
1998-01-01
Two ichnofacies are typical of lacustrine depositional systems. The Scoyenia ichnofacies characterizes transitional terrestrial/nonmarine aquatic substrates, periodically inundated or desiccated, and therefore is commonly present in lake margin facies. The Mermia ichnofacies is associated with well oxygenated, permanent subaqueous, fine-grained substrates of hydrologically open, perennial lakes. Bathymetric zonations within the Mermia ichnofacies are complicated by the wide variability of lacustrine systems. Detected proximal-distal trends are useful within particular lake basins, but commonly difficult to extrapolate to other lakes. Other potential ichnofacies include the typically marine Skolithos ichnofacies for high-energy zones of lakes and substrate-controlled, still unnamed ichnofacies, associated to lake margin deposits. Trace fossils are useful for sedimentologic analysis of event beds. Lacustrine turbidites are characterized by low-diversity suites, reflecting colonization by opportunistic organisms after the turbidite event. Underflow current beds record animal activity contemporaneous with nearly continuous sedimentation. Ichnologic studies may also help to distinguish between marine and lacustrine turbidites. Deep-marine turbidites host the Nereites ichnofacies that consists of high diversity of ornate grazing traces and graphoglyptids, recording highly specialized feeding strategies developed to solve the problem of the scarcity of food in the deep sea. Deep lacustrine environments contain the Mermia ichnofacies, which is dominated by unspecialized grazing and feeding traces probably related to the abundance and accessibility of food in lacustrine systems. The lower diversity of lacustrine ichnofaunas in comparison with deep-sea assemblages more likely reflects lower species diversity as a consequence of less stable conditions. Increase of depth and extent of bioturbation through geologic time produced a clear signature in the ichnofabric record of
Wilkins, D.W.; Scott, W.B.; Kaehler, C.A.
1980-01-01
The study of the Southwest alluvial basins (east) will involve an analysis of the regional aquifer system in parts of Colorado, New Mexico, and Texas. This area has been divided into 22 basins. The study of the alluvial aquifer-system will be made in the following stages: (1) project planning, (2) literature searches, (3) compiling existing data, (4) data collection, (5) basin modeling, (6) regional aquifer modeling, and (7) reports. The regional aquifer study will be accomplished through studying each of the 22 basins. Data compilation and limited data collection will be part of each basin study. Digital computer models will be made for those basins where data are sufficient. A regional aquifer model will be developed from the basin models. In addition to this report, there will be basin hydrology reports and the final regional report. Included in the final report will be a description of the regional hydrology and geology. (USGS)
Heilweil, V.M.; Freethey, G.W.; Wilkowske, C.D.; Stolp, B.J.; Wilberg, D.E.
2000-01-01
Because rapid growth of communities in Washington and Iron Counties, Utah, is expected to cause an increase in the future demand for water resources, a hydrologic investigation was done to better understand ground-water resources within the central Virgin River basin. This study focused on two of the principal ground-water reservoirs within the basin: the upper Ash Creek basin ground-water system and the Navajo and Kayenta aquifer system. The ground-water system of the upper Ash Creek drainage basin consists of three aquifers: the uppermost Quaternary basin-fill aquifer, the Tertiary alluvial-fan aquifer, and the Tertiary Pine Valley monzonite aquifer. These aquifers are naturally bounded by the Hurricane Fault and by drainage divides. On the basis of measurements, estimates, and numerical simulations of reasonable values for all inflow and outflow components, total water moving through the upper Ash Creek drainage basin ground-water system is estimated to be about 14,000 acre-feet per year. Recharge to the upper Ash Creek drainage basin ground-water system is mostly from infiltration of precipitation and seepage from ephemeral and perennial streams. The primary source of discharge is assumed to be evapotranspiration; however, subsurface discharge near Ash Creek Reservoir also may be important. The character of two of the hydrologic boundaries of the upper Ash Creek drainage basin ground-water system is speculative. The eastern boundary provided by the Hurricane Fault is assumed to be a no-flow boundary, and a substantial part of the ground-water discharge from the system is assumed to be subsurface outflow beneath Ash Creek Reservoir along the southern boundary. However, these assumptions might be incorrect because alternative numerical simulations that used different boundary conditions also proved to be feasible. The hydrogeologic character of the aquifers is uncertain because of limited data. Difference in well yield indicate that there is considerable
Voronin, Lois M.; Densmore, Jill N.; Martin, Peter; Brush, Charles F.; Carlson, Carl S.; Miller, David M.
2013-01-01
Groundwater withdrawals began in 1992 from the Langford Basin within the Fort Irwin National Training Center (NTC), California. From April 1992 to December 2010, approximately 12,300 acre-feet of water (averaging about 650 acre-feet per year) has been withdrawn from the basin and transported to the adjacent Irwin Basin. Since withdrawals began, water levels in the basin have declined by as much as 40 feet, and the quality of the groundwater withdrawn from the basin has deteriorated. The U.S. Geological Survey collected geohydrologic data from Langford Basin during 1992–2011 to determine the quantity and quality of groundwater available in the basin. Geophysical surveys, including gravity, seismic refraction, and time-domain electromagnetic induction surveys, were conducted to determine the depth and shape of the basin, to delineate depths to the Quaternary-Tertiary interface, and to map the depth to the water table and changes in water quality. Data were collected from existing wells and test holes, as well as 11 monitor wells that were installed at 5 sites as part of this study. Water-quality samples collected from wells in the basin were used to determine the groundwater chemistry within the basin and to delineate potential sources of poor-quality groundwater. Analysis of stable isotopes of oxygen and hydrogen in groundwater indicates that present-day precipitation is not a major source of recharge to the basin. Tritium and carbon-14 data indicate that most of the basin was recharged prior to 1952, and the groundwater in the basin has an apparent age of 12,500 to 30,000 years. Recharge to the basin, estimated to be less than 50 acre-feet per year, has not been sufficient to replenish the water that is being withdrawn from the basin. A numerical groundwater-flow model was developed for the Langford Basin to better understand the aquifer system used by the Fort Irwin NTC as part of its water supply, and to provide a tool to help manage groundwater resources at
Miller, B.M. )
1990-05-01
Most of the world's energy resources and many of its metallic and mineral resources are derived from complex sources in sedimentary basins. A comprehensive basin analysis requires an understanding of data from many specialties, including sedimentology, stratigraphy geophysics, structural geology, and geochemistry. Such an integrated analysis is almost impossible without a computer. Research efforts in the US Geological Survey are currently being directed at exploring the feasibility of applying expert systems and knowledge acquisition techniques to the design and development of a global system of classification and geological analysis of sedimentary basins to assess their petroleum potential. The primary objective is the design of a prototype object-oriented expert system interfaced with a geographic information system (GIS) that captures both the logic used to define the geologic concepts and the reasoning under uncertainty that enables geologists to understand and reconstruct the geologic history of a sedimentary basin. NEXPERT OBJECT, a hybrid expert system that has the ability to support both a reasoning system and an object-oriented representation, is currently being used as the design tool to provide high-level, expert-oriented features to create, edit, and build knowledge bases for the basin analysis program. This system provides these capabilities through documentation of major basin analysis components such as stratigraphy, structural geology, and sedimentology. It is designed to analyze the traditional concepts of source, reservoir, and trapping mechanism; to help in the diagnosis of geological conditions favorable for the occurrence of petroleum or other energy resources; and to assist in the assessment of these resources. The design and content of the expert system program is discussed for application to basin analysis studies.
SAMSAN- MODERN NUMERICAL METHODS FOR CLASSICAL SAMPLED SYSTEM ANALYSIS
NASA Technical Reports Server (NTRS)
Frisch, H. P.
1994-01-01
SAMSAN was developed to aid the control system analyst by providing a self consistent set of computer algorithms that support large order control system design and evaluation studies, with an emphasis placed on sampled system analysis. Control system analysts have access to a vast array of published algorithms to solve an equally large spectrum of controls related computational problems. The analyst usually spends considerable time and effort bringing these published algorithms to an integrated operational status and often finds them less general than desired. SAMSAN reduces the burden on the analyst by providing a set of algorithms that have been well tested and documented, and that can be readily integrated for solving control system problems. Algorithm selection for SAMSAN has been biased toward numerical accuracy for large order systems with computational speed and portability being considered important but not paramount. In addition to containing relevant subroutines from EISPAK for eigen-analysis and from LINPAK for the solution of linear systems and related problems, SAMSAN contains the following not so generally available capabilities: 1) Reduction of a real non-symmetric matrix to block diagonal form via a real similarity transformation matrix which is well conditioned with respect to inversion, 2) Solution of the generalized eigenvalue problem with balancing and grading, 3) Computation of all zeros of the determinant of a matrix of polynomials, 4) Matrix exponentiation and the evaluation of integrals involving the matrix exponential, with option to first block diagonalize, 5) Root locus and frequency response for single variable transfer functions in the S, Z, and W domains, 6) Several methods of computing zeros for linear systems, and 7) The ability to generate documentation "on demand". All matrix operations in the SAMSAN algorithms assume non-symmetric matrices with real double precision elements. There is no fixed size limit on any matrix in any
SAMSAN- MODERN NUMERICAL METHODS FOR CLASSICAL SAMPLED SYSTEM ANALYSIS
NASA Technical Reports Server (NTRS)
Frisch, H. P.
1994-01-01
SAMSAN was developed to aid the control system analyst by providing a self consistent set of computer algorithms that support large order control system design and evaluation studies, with an emphasis placed on sampled system analysis. Control system analysts have access to a vast array of published algorithms to solve an equally large spectrum of controls related computational problems. The analyst usually spends considerable time and effort bringing these published algorithms to an integrated operational status and often finds them less general than desired. SAMSAN reduces the burden on the analyst by providing a set of algorithms that have been well tested and documented, and that can be readily integrated for solving control system problems. Algorithm selection for SAMSAN has been biased toward numerical accuracy for large order systems with computational speed and portability being considered important but not paramount. In addition to containing relevant subroutines from EISPAK for eigen-analysis and from LINPAK for the solution of linear systems and related problems, SAMSAN contains the following not so generally available capabilities: 1) Reduction of a real non-symmetric matrix to block diagonal form via a real similarity transformation matrix which is well conditioned with respect to inversion, 2) Solution of the generalized eigenvalue problem with balancing and grading, 3) Computation of all zeros of the determinant of a matrix of polynomials, 4) Matrix exponentiation and the evaluation of integrals involving the matrix exponential, with option to first block diagonalize, 5) Root locus and frequency response for single variable transfer functions in the S, Z, and W domains, 6) Several methods of computing zeros for linear systems, and 7) The ability to generate documentation "on demand". All matrix operations in the SAMSAN algorithms assume non-symmetric matrices with real double precision elements. There is no fixed size limit on any matrix in any
A Computer-Based Content Analysis of Interview Texts: Numeric Description and Multivariate Analysis.
ERIC Educational Resources Information Center
Bierschenk, B.
1977-01-01
A method is described by which cognitive structures in verbal data can be identified and categorized through numerical analysis and quantitative description. Transcriptions of interviews (in this case, the verbal statements of 40 researchers) are manually coded and subjected to analysis following the AaO (Agent action Object) paradigm. The texts…
A Computer-Based Content Analysis of Interview Texts: Numeric Description and Multivariate Analysis.
ERIC Educational Resources Information Center
Bierschenk, B.
1977-01-01
A method is described by which cognitive structures in verbal data can be identified and categorized through numerical analysis and quantitative description. Transcriptions of interviews (in this case, the verbal statements of 40 researchers) are manually coded and subjected to analysis following the AaO (Agent action Object) paradigm. The texts…
Summary of research in applied mathematics, numerical analysis, and computer sciences
NASA Technical Reports Server (NTRS)
1986-01-01
The major categories of current ICASE research programs addressed include: numerical methods, with particular emphasis on the development and analysis of basic numerical algorithms; control and parameter identification problems, with emphasis on effective numerical methods; computational problems in engineering and physical sciences, particularly fluid dynamics, acoustics, and structural analysis; and computer systems and software, especially vector and parallel computers.
Analysis of the Tanana River Basin using LANDSAT data
NASA Technical Reports Server (NTRS)
Morrissey, L. A.; Ambrosia, V. G.; Carson-Henry, C.
1981-01-01
Digital image classification techniques were used to classify land cover/resource information in the Tanana River Basin of Alaska. Portions of four scenes of LANDSAT digital data were analyzed using computer systems at Ames Research Center in an unsupervised approach to derive cluster statistics. The spectral classes were identified using the IDIMS display and color infrared photography. Classification errors were corrected using stratification procedures. The classification scheme resulted in the following eleven categories; sedimented/shallow water, clear/deep water, coniferous forest, mixed forest, deciduous forest, shrub and grass, bog, alpine tundra, barrens, snow and ice, and cultural features. Color coded maps and acreage summaries of the major land cover categories were generated for selected USGS quadrangles (1:250,000) which lie within the drainage basin. The project was completed within six months.
Great Basin NV Play Fairway Analysis - Carson Sink
Jim Faulds
2015-10-28
All datasets and products specific to the Carson Sink basin. Includes a packed ArcMap (.mpk), individually zipped shapefiles, and a file geodatabase for the Carson Sink area; a GeoSoft Oasis montaj project containing GM-SYS 2D gravity profiles along the trace of our seismic reflection lines; a 3D model in EarthVision; spreadsheet of links to published maps; and spreadsheets of well data.
NASA Astrophysics Data System (ADS)
Hanson, Andrew Dean
Organic geochemistry of oils from the Tarim basin, NW China, distinguish at least seven genetic groups of oils. The largest group are derived from Middle-Upper Ordovician anoxic slope-facies marls coincident with the margins of structural uplifts. Other groups include non-marine derived oils in the Luntai uplift, from southwest Tarim, in the Kuqa depression, and west of the Bachu uplift. A seep sample from west of Kashi clusters with Luntai oils. These results suggest that numerous source-rock horizons occur, but they are really restricted. Organic geochemistry of oils from northern Qaidam defines a family of hypersaline, anoxic lacustrine derived oils. Cenozoic outcrop samples from northern Qaidam are too organic lean to be of source quality, but dark laminated upper Oligocene mudstones from the Shi 28 well are of fair to good quality. Biomarkers provide a good correlation between the oils and the core samples. Organic matter is from algae and bacteria and lacks terrestrial material. Hydrocarbons are contained in upper Oligocene, Miocene, and Pliocene reservoirs. Eight oils are from NW Qaidam, but one sample comes from NE Qaidam, an area previously believed to only produce oils derived from Jurassic source rocks. Thus an unidentified Cenozoic source rock occurs in NE Qaidam. Thermal modeling indicates generation occurred in northwestern Qaidam within the last 3 million years, agreeing with observed low maturity biomarker parameters. Cenozoic stratigraphy in northern Qaidam and southern Tarim basins record the tectonic history of the surrounding structural/topographic elements. Paleocurrents record flow away from adjacent ranges from the Miocene to the present. Provenance data tie sediments to adjacent structural elements. Petrography indicates increasingly immature sandstones in Miocene and younger sediments relative to pre-Miocene samples. Apatite fission-track results from southeastern Tarim yield a cooling age of 17 +/- 1 Ma indicative of unroofing since at
Ernest Mancini
2000-12-31
Part 3 (Petroleum System Modeling of the Jurassic Smackover Formation) objectives are to provide an analysis of the Smackover petroleum system in Years 4 and 5 of the project and to transfer effectively the research results to producers through workshops and topical reports. Work Accomplished (Year 5): Task 1 - Basin Flow - Basin flow modeling has been completed and the modeling results are being interpreted for report writing (Table 1). Task 2 - Petroleum Source Rocks - Work on the characterization of Smackover petroleum source rocks has been integrated into the basin flow model. Task 3 - Petroleum Reservoirs - Work on the characterization of Smackover petroleum reservoirs continues. The cores to be described have been identified and many of the cores for the eastern part of the basin have been described. Task 4 - Reservoir Diagenesis - Work on reservoir diagenesis has been initiated. Samples from the cores selected for the reservoir characterization are being used for this task. Work Planned (Year 5): Task 1 - Basin Flow - The report on basin flow will be completed. Task 2 - Petroleum Source Rocks - Petroleum source rock data will be reviewed in light of the basin flow model results. Task 3 - Petroleum Reservoirs - Characterization of petroleum reservoirs will continue through core studies. Task 4 - Reservoir Diagenesis - Characterization of reservoir diagenesis will continue through petrographic analysis.
Ernest A. Mancini; Donald A. Goddard
2005-08-01
The principal research effort for Year 3 of the project is basin modeling and petroleum system identification, comparative basin evaluation and resource assessment. In the first six (6) months of Year 3, the research focus is on basin modeling and petroleum system identification and the remainder of the year the emphasis is on the comparative basin evaluation and resource assessment. No major problems have been encountered to date, and the project is on schedule.
Weber, L.J.; Sarg, J.F.; Armentrout, J.M.
1996-12-31
Analysis of seismic, outcrop, core, and log data into a stratigraphic hierarchy for the Middle Pennsylvanian mixed carbonate, siliciclastic, and evaporate strata of the Paradox basin, southwest USA allows for an improved prediction of reservoir, source, and seal. Facies stacking patterns indicate that 5th-order depositional cycles ({ge} 100 k.y.), stack into 4th-order depositional sequences ({approximately}400 k.y.), each with lowstand, transgressive, and highstand systems tracts. This framework comprises the reservoir architecture of the giant Aneth field. Fourth-order sequences stack into seismically resolvable, biostratigraphically defined 3rd-order composite sequences ({approximately}1.5 m.y.). Secondary porosity is most pronounced in highstands beneath 3rd-order sequence boundaries. Five 3rd-order sequences make up part of an Atokan-Missourian 2nd-order transgressive-Tegressive cycle. This framework is used to predict the regional distribution of reservoir, source, and seal. A second-order relative rise in sea level during the lower three 3rd-order sequences (Atokan-E. Desmoinesian) resulted in a basin-rimming carbonate shelf that backsteps through time. During 3rd-order lowstands, basin restriction and drawdown resulted in accumulation of subaqueous evaporates. Third-order transgressions over vast evaporate deposits led to dissolution, elevated salinity, and high organic productivity. These source rocks are basinwide in extent. The ensuing turnaround and initiation of the 2nd-order fall in sea level resulted in rapid progradation of the carbonate shelf. Drawdown was sufficient during 4th-order lowstands to allow shallow subaqueous evaporates to accumulate in each 3rd-order sequence. World-class reservoirs formed in algal buildup and grainstone facies of the 3rd-order highstand above the 2nd-order turn- around. Seal facies overlie reservoirs and are composed of lowstand evaporates and transgressive carbonates.
Weber, L.J.; Sarg, J.F.; Armentrout, J.M. )
1996-01-01
Analysis of seismic, outcrop, core, and log data into a stratigraphic hierarchy for the Middle Pennsylvanian mixed carbonate, siliciclastic, and evaporate strata of the Paradox basin, southwest USA allows for an improved prediction of reservoir, source, and seal. Facies stacking patterns indicate that 5th-order depositional cycles ([ge] 100 k.y.), stack into 4th-order depositional sequences ([approximately]400 k.y.), each with lowstand, transgressive, and highstand systems tracts. This framework comprises the reservoir architecture of the giant Aneth field. Fourth-order sequences stack into seismically resolvable, biostratigraphically defined 3rd-order composite sequences ([approximately]1.5 m.y.). Secondary porosity is most pronounced in highstands beneath 3rd-order sequence boundaries. Five 3rd-order sequences make up part of an Atokan-Missourian 2nd-order transgressive-Tegressive cycle. This framework is used to predict the regional distribution of reservoir, source, and seal. A second-order relative rise in sea level during the lower three 3rd-order sequences (Atokan-E. Desmoinesian) resulted in a basin-rimming carbonate shelf that backsteps through time. During 3rd-order lowstands, basin restriction and drawdown resulted in accumulation of subaqueous evaporates. Third-order transgressions over vast evaporate deposits led to dissolution, elevated salinity, and high organic productivity. These source rocks are basinwide in extent. The ensuing turnaround and initiation of the 2nd-order fall in sea level resulted in rapid progradation of the carbonate shelf. Drawdown was sufficient during 4th-order lowstands to allow shallow subaqueous evaporates to accumulate in each 3rd-order sequence. World-class reservoirs formed in algal buildup and grainstone facies of the 3rd-order highstand above the 2nd-order turn- around. Seal facies overlie reservoirs and are composed of lowstand evaporates and transgressive carbonates.
Rio Hondo Sediment Assessment Analysis Using SAM. Numerical Model Investigation
1991-05-01
Distribution Unlimited 91-05652 SU Army1ngi11er Ds i lbuquerque Prepared for US Army Engineer District, Albuquerque Albuquerque, New Mexico 87103-1580 LB...Roswell, New Mexico , is located in the southwestern part of New Mexico in the Pecos River watershed (Figure 1). The source of the Pecos River basin...Report, Two Rivers Reservoir, New Mexico ," prepared for US Army Engineer District, Albuquerque, by Resource Technology, Albuquerque, NM. 5 Rio Hondo
Numerical Analysis of Turbulent Flow in Porous Media
NASA Astrophysics Data System (ADS)
Hassanipour, Fatemeh; Catoe, James K.; Lage, Jose
2008-11-01
Modeling techniques and simulation of laminar flow through porous media have been applied for a number of years for designing particulate filters, catalytic reactors, thermal and sound insulators, combustors, and more recently fuel cells. Essential for further analysis, and in support of new synthesis, is the modeling necessary for simulating turbulent flows in porous media. This has been studied in the present work, in principle, through modeling that is an alternative to Direct Numerical Simulation. A natural approach to build a turbulence model for flow in porous media is to simply apply the time averaging (for handling turbulence) and the space averaging (for handling the morphology) to the microscopic equations valid at the pore level. When pursuing a combined time and space averaging approach, the averaging order (i.e. space-time or time-space) matters. The difference in pursuing a time-space or a space-time averaging order is now known to essentially impact the way in which the resulting model treats the interaction of a large flow structure. In the current study, these two different approaches have been investigated in parallel to the experiments for their validity range. The comparisons are based on flow structure visualization and on values of turbulence characteristics obtained from direct measurements of fluid velocity via digital particle image velocimetry.
Discomfort Analysis in Computerized Numeric Control Machine Operations
Sankaranarayanasamy, Krishnasamy; Ganguli, Anindya Kumar
2012-01-01
Objectives The introduction of computerized numeric control (CNC) technology in manufacturing industries has revolutionized the production process, but there are some health and safety problems associated with these machines. The present study aimed to investigate the extent of postural discomfort in CNC machine operators, and the relationship of this discomfort to the display and control panel height, with a view to validate the anthropometric recommendation for the location of the display and control panel in CNC machines. Methods The postural discomforts associated with CNC machines were studied in 122 male operators using Corlett and Bishop's body part discomfort mapping, subject information, and discomfort level at various time intervals from starting to end of a shift. This information was collected using a questionnaire. Statistical analysis was carried out using ANOVA. Results Neck discomfort due to the positioning of the machine displays, and shoulder and arm discomfort due to the positioning of controls were identified as common health issues in the operators of these machines. The study revealed that 45.9% of machine operators reported discomfort in the lower back, 41.8% in the neck, 22.1% in the upper-back, 53.3% in the shoulder and arm, and 21.3% of the operators reported discomfort in the leg. Conclusion Discomfort increased with the progress of the day and was highest at the end of a shift; subject age had no effect on patient tendency to experience discomfort levels. PMID:22993720
The design and numerical analysis of tandem thermophotovoltaic cells
NASA Astrophysics Data System (ADS)
Yang, Hao-Yu; Liu, Ren-Jun; Wang, Lian-Kai; Lü, You; Li, Tian-Tian; Li, Guo-Xing; Zhang, Yuan-Tao; Zhang, Bao-Lin
2013-10-01
In this paper, numerical analysis of GaSb =(Eg = 0.72 eV)/Ga0.84In0.16As0.14Sb0.86 (Eg = 0.53 eV) tandem thermophotovoltaic (TPV) cells is carried out by using Silvaco/Atlas software. In the tandem cells, a GaSb p-n homojunction is used for the top cell and a GaInAsSb p-n homojunction for the bottom cell. A heavily doped GaSb tunnel junction connects the two sub-cells together. The simulations are carried out at a radiator temperature of 2000 K and a cell temperature of 300 K. The radiation photons are injected from the top of the tandem cells. Key properties of the single- and dual-junction TPV cells, including I-V characteristic, maximum output power (Pmax), open-circuit voltage (Voc), short-circuit current (Isc), etc. are presented. The effects of the sub-cell thickness and carrier concentration on the key properties of tandem cells are investigated. A comparison of the dual-TPV cells with GaSb and GaInAsSb single junction cells shows that the Pmax of tandem cells is almost twice as great as that of the single-junction cells.
Direct Numerical Simulation of Combustion Using Principal Component Analysis
NASA Astrophysics Data System (ADS)
Owoyele, Opeoluwa; Echekki, Tarek
2016-11-01
We investigate the potential of accelerating chemistry integration during the direct numerical simulation (DNS) of complex fuels based on the transport equations of representative scalars that span the desired composition space using principal component analysis (PCA). The transported principal components (PCs) offer significant potential to reduce the computational cost of DNS through a reduction in the number of transported scalars, as well as the spatial and temporal resolution requirements. The strategy is demonstrated using DNS of a premixed methane-air flame in a 2D vortical flow and is extended to the 3D geometry to further demonstrate the computational efficiency of PC transport. The PCs are derived from a priori PCA of a subset of the full thermo-chemical scalars' vector. The PCs' chemical source terms and transport properties are constructed and tabulated in terms of the PCs using artificial neural networks (ANN). Comparison of DNS based on a full thermo-chemical state and DNS based on PC transport based on 6 PCs shows excellent agreement even for species that are not included in the PCA reduction. The transported PCs reproduce some of the salient features of strongly curved and strongly strained flames. The 2D DNS results also show a significant reduction of two orders of magnitude in the computational cost of the simulations, which enables an extension of the PCA approach to 3D DNS under similar computational requirements. This work was supported by the National Science Foundation Grant DMS-1217200.
Analysis of Numerical Simulation Results of LIPS-200 Lifetime Experiments
NASA Astrophysics Data System (ADS)
Chen, Juanjuan; Zhang, Tianping; Geng, Hai; Jia, Yanhui; Meng, Wei; Wu, Xianming; Sun, Anbang
2016-06-01
Accelerator grid structural and electron backstreaming failures are the most important factors affecting the ion thruster's lifetime. During the thruster's operation, Charge Exchange Xenon (CEX) ions are generated from collisions between plasma and neutral atoms. Those CEX ions grid's barrel and wall frequently, which cause the failures of the grid system. In order to validate whether the 20 cm Lanzhou Ion Propulsion System (LIPS-200) satisfies China's communication satellite platform's application requirement for North-South Station Keeping (NSSK), this study analyzed the measured depth of the pit/groove on the accelerator grid's wall and aperture diameter's variation and estimated the operating lifetime of the ion thruster. Different from the previous method, in this paper, the experimental results after the 5500 h of accumulated operation of the LIPS-200 ion thruster are presented firstly. Then, based on these results, theoretical analysis and numerical calculations were firstly performed to predict the on-orbit lifetime of LIPS-200. The results obtained were more accurate to calculate the reliability and analyze the failure modes of the ion thruster. The results indicated that the predicted lifetime of LIPS-200's was about 13218.1 h which could satisfy the required lifetime requirement of 11000 h very well.
Numeric calculation of celestial bodies with spreadsheet analysis
NASA Astrophysics Data System (ADS)
Koch, Alexander
2016-04-01
The motion of the planets and moons in our solar system can easily be calculated for any time by the Kepler laws of planetary motion. The Kepler laws are a special case of the gravitational law of Newton, especially if you consider more than two celestial bodies. Therefore it is more basic to calculate the motion by using the gravitational law. But the problem is, that by gravitational law it is not possible to calculate the state of motion with only one step of calculation. The motion has to be numerical calculated for many time intervalls. For this reason, spreadsheet analysis is helpful for students. Skills in programmes like Excel, Calc or Gnumeric are important in professional life and can easily be learnt by students. These programmes can help to calculate the complex motions with many intervalls. The more intervalls are used, the more exact are the calculated orbits. The sutdents will first get a quick course in Excel. After that they calculate with instructions the 2-D-coordinates of the orbits of Moon and Mars. Step by step the students are coding the formulae for calculating physical parameters like coordinates, force, acceleration and velocity. The project is limited to 4 weeks or 8 lessons. So the calcualtion will only include the calculation of one body around the central mass like Earth or Sun. The three-body problem can only be shortly discussed at the end of the project.
Numerical Simulation and Scaling Analysis of Cell Printing
NASA Astrophysics Data System (ADS)
Qiao, Rui; He, Ping
2011-11-01
Cell printing, i.e., printing three dimensional (3D) structures of cells held in a tissue matrix, is gaining significant attention in the biomedical community. The key idea is to use inkjet printer or similar devices to print cells into 3D patterns with a resolution comparable to the size of mammalian cells. Achieving such a resolution in vitro can lead to breakthroughs in areas such as organ transplantation. Although the feasibility of cell printing has been demonstrated recently, the printing resolution and cell viability remain to be improved. Here we investigate a unit operation in cell printing, namely, the impact of a cell-laden droplet into a pool of highly viscous liquids. The droplet and cell dynamics are quantified using both direct numerical simulation and scaling analysis. These studies indicate that although cell experienced significant stress during droplet impact, the duration of such stress is very short, which helps explain why many cells can survive the cell printing process. These studies also revealed that cell membrane can be temporarily ruptured during cell printing, which is supported by indirect experimental evidence.
A network landscape model: stability analysis and numerical tests
NASA Astrophysics Data System (ADS)
Bonacini, E.; Groppi, M.; Monaco, R.; Soares, A. J.; Soresina, C.
2017-07-01
A Network Landscape Model (NLM) for the evaluation of the ecological trend of an environmental system is here presented and investigated. The model consists in a network of dynamical systems, where each node represents a single Landscape Unit (LU), endowed by a system of ODEs for two variables relevant to the production of bio-energy and to the percentage of green areas, respectively. The main goal of the paper consists in testing the relevance of connectivity between the LUs. For this purpose we consider first the Single LU Model (SLM) and investigate its equilibria and their stability, in terms of two bifurcation parameters. Then the network dynamics is theoretically investigated by means of a bifurcation analysis of a proper simplified differential system, that allows to understand how the coupling between different LUs modifies the asymptotic scenarios for the single LU model. Numerical simulations of NLM are performed, with reference to an environmental system in Northern Italy, and results are discussed in connection with SLM.
Numerical Analysis of Orbital Perturbation Effects on Inclined Geosynchronous SAR
Dong, Xichao; Hu, Cheng; Long, Teng; Li, Yuanhao
2016-01-01
The geosynchronous synthetic aperture radar (GEO SAR) is susceptible to orbit perturbations, leading to orbit drifts and variations. The influences behave very differently from those in low Earth orbit (LEO) SAR. In this paper, the impacts of perturbations on GEO SAR orbital elements are modelled based on the perturbed dynamic equations, and then, the focusing is analyzed theoretically and numerically by using the Systems Tool Kit (STK) software. The accurate GEO SAR slant range histories can be calculated according to the perturbed orbit positions in STK. The perturbed slant range errors are mainly the first and second derivatives, leading to image drifts and defocusing. Simulations of the point target imaging are performed to validate the aforementioned analysis. In the GEO SAR with an inclination of 53° and an argument of perigee of 90°, the Doppler parameters and the integration time are different and dependent on the geometry configurations. Thus, the influences are varying at different orbit positions: at the equator, the first-order phase errors should be mainly considered; at the perigee and apogee, the second-order phase errors should be mainly considered; at other positions, first-order and second-order exist simultaneously. PMID:27598168
Numerical Analysis of Orbital Perturbation Effects on Inclined Geosynchronous SAR.
Dong, Xichao; Hu, Cheng; Long, Teng; Li, Yuanhao
2016-09-02
The geosynchronous synthetic aperture radar (GEO SAR) is susceptible to orbit perturbations, leading to orbit drifts and variations. The influences behave very differently from those in low Earth orbit (LEO) SAR. In this paper, the impacts of perturbations on GEO SAR orbital elements are modelled based on the perturbed dynamic equations, and then, the focusing is analyzed theoretically and numerically by using the Systems Tool Kit (STK) software. The accurate GEO SAR slant range histories can be calculated according to the perturbed orbit positions in STK. The perturbed slant range errors are mainly the first and second derivatives, leading to image drifts and defocusing. Simulations of the point target imaging are performed to validate the aforementioned analysis. In the GEO SAR with an inclination of 53° and an argument of perigee of 90°, the Doppler parameters and the integration time are different and dependent on the geometry configurations. Thus, the influences are varying at different orbit positions: at the equator, the first-order phase errors should be mainly considered; at the perigee and apogee, the second-order phase errors should be mainly considered; at other positions, first-order and second-order exist simultaneously.
1-D Numerical Analysis of RBCC Engine Performance
NASA Technical Reports Server (NTRS)
Han, Samuel S.
1998-01-01
An RBCC engine combines air breathing and rocket engines into a single engine to increase the specific impulse over an entire flight trajectory. Considerable research pertaining to RBCC propulsion was performed during the 1960's and these engines were revisited recently as a candidate propulsion system for either a single-stage-to-orbit (SSTO) or two-stage-to-orbit (TSTO) launch vehicle. There are a variety of RBCC configurations that had been evaluated and new designs are currently under development. However, the basic configuration of all RBCC systems is built around the ejector scramjet engine originally developed for the hypersonic airplane. In this configuration, a rocket engine plays as an ejector in the air-augmented initial acceleration mode, as a fuel injector in scramjet mode and the rocket in all rocket mode for orbital insertion. Computational fluid dynamics (CFD) is a useful tool for the analysis of complex transport processes in various components in RBCC propulsion systems. The objective of the present research was to develop a transient 1-D numerical model that could be used to predict flow behavior throughout a generic RBCC engine following a flight path.
Experimental and numerical analysis of cylindrical straw drying
NASA Astrophysics Data System (ADS)
Goryl, Wojciech; Filipowicz, Mariusz
The paper presents experimental and numerical results of the heat and mass transfer in a cylindrical bale of straw. The experimental measurements were made in a specialized stand of straw driers. Flue gasses, comes from straw combustion in the biomass boiler, are used as a drying medium. There were made measurements of humidity and temperature inside the cylindrical straw bale during the drying process. The results were used to prepare the drying rate curve. Moreover, data were used to validate the numerical model of straw drying. The numerical model was performed to depict the heat and mass transfer inside the straw bale. Furthermore, the model was used to optimize the drying process. The paper presents result of experimental and numerical drying rates of cylindrical straw bale and heat and mass transfer in its interior. As a result of the work numerical model was obtained. It satisfactorily describes the mechanisms inside the drying straw bale.
NASA Astrophysics Data System (ADS)
Empinotti, Thais; Spychala, Yvonne; Luthi, Stefan; Hodgson, David
2016-04-01
The depositional architectures of deep-water turbiditic deposits are strongly influenced by seafloor topography. Slope gradient variations of less than one degree might be sufficient to change the distribution of sands significantly along the basin profile. Stratigraphic units of deep-water sandstones from the Fort Brown Fm. in the Laingsburg depocentre (Karoo Basin, South Africa) are an example of that. Regional mapping and stratigraphic correlation of Units C to F (Van der Merwe et al., 2014) show a change from sand-attached systems in Units C and D to sand-detached systems in Units E and F. The sand-attached systems show a continuity of sands from entrenched slope valleys to basin-floor lobe complexes, while in the sand-detached systems there are widespread sand bypass zones of approximately 10 to 30 km where almost no sand is deposited and erosive features are observed. This is interpreted to reflect the development of a stepped slope profile. Lobe deposits occur before and after the bypass region, but significant differences in depositional architecture are noticed between these lobe deposits. The intraslope lobes are characterized by an aggradational to compensational stacking pattern and a common occurrence of erosive features, while the basin floor lobes show a lateral compensating stacking pattern with less erosive features. In this study, process-based numerical modelling of turbidity currents are performed to test if a stepped slope to basin profile with subtle gradient changes similar to that interpreted for the Laingsburg depocentre during the deposition of Unit E are suitable to generate the sediment distribution pattern observed in the field. Through an iterative modelling workflow we aim to constrain the paleoslope gradient changes using the parameters constrained from outcrop. The study also investigates how flow parameters such as sediment concentration, flow velocity, flow thickness and Froude number behave as a function of different slope
A numerical study of strike-slip bend formation with application to the Salton Sea pull-apart basin
NASA Astrophysics Data System (ADS)
Ye, Jiyang; Liu, Mian; Wang, Hui
2015-03-01
How stepovers of strike-slip faults connect to form bends is a question important for understanding the formation of push-up ranges (restraining bends) and pull-apart basins (releasing bends). We investigated the basic mechanics of this process in a simple three-dimensional viscoelastoplastic finite element model. Our model predicts localized plastic strain within stepovers that may eventually lead to the formation of strike-slip bends. Major parameters controlling strain localization include the relative fault strength, geometry of the fault system, and the plasticity model assumed. Using the Drucker-Prager plasticity model, in which the plastic yield strength of the crust depends on both shear and normal stresses, our results show that a releasing bend is easier to develop than a restraining bend under similar conditions. These results may help explain the formation of the Salton Sea pull-apart basin in Southern California 0.5-0.1 Ma ago, when the stepover between the Imperial Fault and the San Andreas Fault was connected by the Brawley seismic zone.
Numerical analysis of discrete fractional integrodifferential structural dampers
NASA Technical Reports Server (NTRS)
Padovan, Joseph
1987-01-01
This paper develops solution algorithms enabling the handling of the dynamic response of nonlinear structures contained discretely attached dampers modeled by fractional integrodifferential operators of the Grunwald-Liouville-Riemann type. The development consists of two levels of formulation, namely: (1) numerical approximations of fractional operators and, (2) the establishment of global level implicit schemes enabling the solution to nonlinear structural formulations. To generalize the overall results, error estimates are derived for the fractional operator approximation algorithm. These enable an ongoing optimization of solution efficiency for a given error tolerance. To benchmark the scheme, the results of several numerical experiments are presented. These illustrate the numerical characteristics of the overall formulation.
Dartnell, P.; Gardner, J.V.
2009-01-01
The seafloor off greater Los Angeles, California, has been extensively studied for the past century. Terrain analysis of recently compiled multibeam bathymetry reveals the detailed seafloor morphology along the Los Angeles Margin and San Pedro Basin. The terrain analysis uses the multibeam bathymetry to calculate two seafloor indices, a seafloor slope, and a Topographic Position Index. The derived grids along with depth are analyzed in a hierarchical, decision-tree classification to delineate six seafloor provinces-high-relief shelf, low-relief shelf, steep-basin slope, gentle-basin slope, gullies and canyons, and basins. Rock outcrops protrude in places above the generally smooth continental shelf. Gullies incise the steep-basin slopes, and some submarine canyons extend from the coastline to the basin floor. San Pedro Basin is separated from the Santa Monica Basin to the north by a ridge consisting of the Redondo Knoll and the Redondo Submarine Canyon delta. An 865-m-deep sill separates the two basins. Water depths of San Pedro Basin are ??100 m deeper than those in the San Diego Trough to the south, and three passes breach a ridge that separates the San Pedro Basin from the San Diego Trough. Information gained from this study can be used as base maps for such future studies as tectonic reconstructions, identifying sedimentary processes, tracking pollution transport, and defining benthic habitats. ?? 2009 The Geological Society of America.
NASA Astrophysics Data System (ADS)
Nakayama, K.; Maruya, Y.; Matsumoto, K.; Komata, M.; Komai, K.; Kuwae, T.
2015-04-01
Since marine derived nutrients (MDN) are transported not only in river channels but also across the entire river basin, including via ground water and migratory animals, it is necessary to investigate the contribution of MDN to the forest floor (soils) in order to quantify the true role of MDN at the river ecosystem scale. This study investigated the contribution of pink (Oncorhynchus gorbuscha) and chum salmon (O. keta) to total oceanic nitrogen (TN) input across a river basin using stable isotope analysis (SIA) of nitrogen (δ15N). The contribution of TN entering the river basin by salmon was 23.8 % relative to the total amount of TN exported from the river basin, providing a first estimate of MDN export for a river basin. The contribution of nitrogen from the ocean to the river basin soils was between 22.9 and 23.8 %. Furthermore, SIA showed that the transport of oceanic TN by sea eagles (Haliaeetus spp.) was greater than that by bears (Ursus arctos), which had previously been that bears are thought to be the major animal transporter of nutrients in the northern part of Japan.
Noel, J.A.; Cole, J.; Innes, C.; Juzwick, S.
1987-09-01
In May 1986, the Ohio Board of Regents awarded a research grant to Ashland College to investigate the basinal origin of crude oil through trace-element analysis. The major thrust of the project was to attempt to finger print crude oils of various ages and depths from the northern Appalachian, eastern Illinois, and southern Michigan basins, to learn if the oldest crudes may have migrated among the basins. This in turn might give a more definitive time for the separation of the three basins. Nickel to vanadium ratios, were chosen to be the discriminators. Nickel to vanadium ratios show that the Trenton oil from the fields at Lima, Ohio; Oak Harbor in Ottawa County, Ohio; Urbana, Indiana; Peru, Indiana; and Albion, Michigan, are all different. The Trempealeau oils in Harmony and Lincoln Townships, Morrow County, are similar but they are different from those in Peru and Bennington Townships. The Devonian oils of the Illinois and Appalachian basins are distinctly different. The Berea oil shows little or no variability along strike. The Mississippian oils of the Illinois basin are different from the Berea oils and the Salem oil is different from the Chester. The only thing consistent about the Clinton is its inconsistency.
Tularosa Basin Play Fairway Analysis: Hydrothermal Alteration Map
Adam Brandt
2015-11-15
This is a hydrothermal alteration map of the Tularosa Basin area, New Mexico and Texas that was created using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) multispectral data band ratios based upon diagnostic features of clay, calcite, silica, gypsum, ferric iron, and ferrous iron. Mesoproterozoic granite in the San Andreas Range often appeared altered, but this may be from clays produced by weathering or, locally, by hydrothermal alteration. However, no field checking was done. This work was done under U.S. D.O.E. Contract #DE-EE0006730
Numerical analysis of the sea state bias for satellite altimetry
NASA Astrophysics Data System (ADS)
Glazman, R. E.; Fabrikant, A.; Srokosz, M. A.
1996-02-01
Theoretical understanding of the dependence of sea state bias (SSB) on wind wave conditions has been achieved only for the case of a unidirectional wind-driven sea [Jackson, 1979; Rodriguez et al., 1992; Glazman and Srokosz, 1991]. Recent analysis of Geosat and TOPEX altimeter data showed that additional factors, such as swell, ocean currents, and complex directional properties of realistic wave fields, may influence SSB behavior. Here we investigate effects of two-dimensional multimodal wave spectra using a numerical model of radar reflection from a random, non-Gaussian surface. A recently proposed ocean wave spectrum is employed to describe sea surface statistics. The following findings appear to be of particular interest: (1) Sea swell has an appreciable effect in reducing the SSB coefficient compared with the pure wind sea case but has less effect on the actual SSB, owing to the corresponding increase in significant wave height. (2) Hidden multimodal structure (the two-dimensional wavenumber spectrum contains separate peaks, for swell and wind seas, while the frequency spectrum looks unimodal) results in an appreciable change of SSB. (3) For unimodal, purely wind-driven seas, the influence of the angular spectral width is relatively unimportant; that is, a unidirectional sea provides a good qualitative model for SSB if the swell is absent. (4) The pseudo wave age is generally much better for parametrizing the SSB coefficient than the actual wave age (which is ill-defined for a multimodal sea) or wind speed. (5) SSB can be as high as 5% of the significant wave height, which is significantly greater than predicted by present empirical model functions tuned on global data sets. (6) Parameterization of SSB in terms of wind speed is likely to lead to errors due to the dependence on the (in practice, unknown) fetch.
Numerical Analysis of the Sea State Bias for Satellite Altimetry
NASA Technical Reports Server (NTRS)
Glazman, R. E.; Fabrikant, A.; Srokosz, M. A.
1996-01-01
Theoretical understanding of the dependence of sea state bias (SSB) on wind wave conditions has been achieved only for the case of a unidirectional wind-driven sea. Recent analysis of Geosat and TOPEX altimeter data showed that additional factors, such as swell, ocean currents, and complex directional properties of realistic wave fields, may influence SSB behavior. Here we investigate effects of two-dimensional multimodal wave spectra using a numerical model of radar reflection from a random, non-Gaussian surface. A recently proposed ocean wave spectrum is employed to describe sea surface statistics. The following findings appear to be of particular interest: (1) Sea swell has an appreciable effect in reducing the SSB coefficient compared with the pure wind sea case but has less effect on the actual SSB owing to the corresponding increase in significant wave height. (2) Hidden multimodal structure (the two-dimensional wavenumber spectrum contains separate peaks, for swell and wind seas, while the frequency spectrum looks unimodal) results in an appreciable change of SSB. (3) For unimodal, purely wind-driven seas, the influence of the angular spectral width is relatively unimportant; that is, a unidirectional sea provides a good qualitative model for SSB if the swell is absent. (4) The pseudo wave age is generally much better fo parametrization the SSB coefficient than the actual wave age (which is ill-defined for a multimodal sea) or wind speed. (5) SSB can be as high as 5% of the significant wave height, which is significantly greater than predicted by present empirical model functions tuned on global data sets. (6) Parameterization of SSB in terms of wind speed is likely to lead to errors due to the dependence on the (in practice, unknown) fetch.
Numerical analysis of fume formation mechanism in arc welding
NASA Astrophysics Data System (ADS)
Tashiro, Shinichi; Zeniya, Tasuku; Yamamoto, Kentaro; Tanaka, Manabu; Nakata, Kazuhiro; Murphy, Anthony B.; Yamamoto, Eri; Yamazaki, Kei; Suzuki, Keiichi
2010-11-01
In order to clarify the fume formation mechanism in arc welding, a quantitative investigation based on the knowledge of interaction among the electrode, arc and weld pool is indispensable. A fume formation model consisting of a heterogeneous condensation model, a homogeneous nucleation model and a coagulation model has been developed and coupled with the GTA or GMA welding model. A series of processes from evaporation of metal vapour to fume formation from the metal vapour was totally investigated by employing this simulation model. The aim of this paper is to visualize the fume formation process and clarify the fume formation mechanism theoretically through a numerical analysis. Furthermore, the reliability of the simulation model was also evaluated through a comparison of the simulation result with the experimental result. As a result, it was found that the size of the secondary particles consisting of small particles with a size of several tens of nanometres reached 300 nm at maximum and the secondary particle was in a U-shaped chain form in helium GTA welding. Furthermore, it was also clarified that most part of the fume was produced in the downstream region of the arc originating from the metal vapour evaporated mainly from the droplet in argon GMA welding. The fume was constituted by particles with a size of several tens of nanometres and had similar characteristics to that of GTA welding. On the other hand, if the metal transfer becomes unstable and the metal vapour near the droplet diffuses directly towards the surroundings of the arc not getting into the plasma flow, the size of the particles reaches several hundred nanometres.
ANALYSIS OF A NUMERICAL SOLVER FOR RADIATIVE TRANSPORT EQUATION.
Gao, Hao; Zhao, Hongkai
2013-01-01
We analyze a numerical algorithm for solving radiative transport equation with vacuum or reflection boundary condition that was proposed in [4] with angular discretization by finite element method and spatial discretization by discontinuous Galerkin or finite difference method.
Numerical Grid Generation and Potential Airfoil Analysis and Design
1988-01-01
contents include a discussion of grid generation concepts and schemes in the literature , iter- ative methods for numerical grid generation and two...to multicomponent rN airfoils, arbitrary multiple bodies and cascade grid generation for the first time. We present representative results as a... literature , iter- ative methods for numerical grid generation and two differential grid gen- eration schemes: (1) an elliptic, and (2) a parabolic scheme. A
Numerical analysis of incompressible viscous flow around a bubble
NASA Astrophysics Data System (ADS)
Sugano, Minoru; Ishii, Ryuji; Morioka, Shigeki
1992-12-01
A numerical simulation of flows around a deformable gas bubble rising through an incompressible viscous fluid is carried out on a supercomputer Fujitsu VP-2600 at the Data Processing Center of Kyoto University. The solution algorithm is a modified MAC (Marker And Cell) method. For the grid generation, an orthogonal mapping proposed by Ryskin and Leal is applied. The numerical results are compared with Ryskin and Leal's results and previous experiments. It will be shown that a good agreement is obtained between them.
Numerical analysis, scientific computing and fundamental studies of fluid mechanics
NASA Astrophysics Data System (ADS)
1989-08-01
This paper briefly discusses the following topics: vortex dynamics, vortical flow and separated flow; free surface flows at low Reynolds number; concurrent linear algebra routines; concurrent continuation and invariant manifolds; concurrent multigrid continuation methods; AUTO-software; Taylor-vortex flows; boundary conditions for infinite domains; numerical and analytical studies of evolutionary systems; numerical methods for stiff differential equations; vortex reconnection; and a study of finite amplitude bifurcations in plane Poiseuille flow.
Sheet Hydroforming Process Numerical Model Improvement Through Experimental Results Analysis
NASA Astrophysics Data System (ADS)
Gabriele, Papadia; Antonio, Del Prete; Alfredo, Anglani
2010-06-01
The increasing application of numerical simulation in metal forming field has helped engineers to solve problems one after another to manufacture a qualified formed product reducing the required time [1]. Accurate simulation results are fundamental for the tooling and the product designs. The wide application of numerical simulation is encouraging the development of highly accurate simulation procedures to meet industrial requirements. Many factors can influence the final simulation results and many studies have been carried out about materials [2], yield criteria [3] and plastic deformation [4,5], process parameters [6] and their optimization. In order to develop a reliable hydromechanical deep drawing (HDD) numerical model the authors have been worked out specific activities based on the evaluation of the effective stiffness of the blankholder structure [7]. In this paper after an appropriate tuning phase of the blankholder force distribution, the experimental activity has been taken into account to improve the accuracy of the numerical model. In the first phase, the effective capability of the blankholder structure to transfer the applied load given by hydraulic actuators to the blank has been explored. This phase ended with the definition of an appropriate subdivision of the blankholder active surface in order to take into account the effective pressure map obtained for the given loads configuration. In the second phase the numerical results obtained with the developed subdivision have been compared with the experimental data of the studied model. The numerical model has been then improved, finding the best solution for the blankholder force distribution.
NASA Astrophysics Data System (ADS)
Wichura, Henry; Quinteros, Javier; Melnick, Daniel; Brune, Sascha; Schwanghart, Wolfgang; Strecker, Manfred R.
2015-04-01
Over the last four years sedimentologic and thermochronologic studies in the western and eastern branches of the Cenozoic East African Rift System (EARS) have supported the notion of a broadly contemporaneous onset of normal faulting and rift-basin formation in both segments. These studies support previous interpretations based on geophysical investigations from which an onset of rifting during the Paleogene had been postulated. In light of these studies we explore the evolution of the Lake Victoria basin, a shallow, unfaulted sedimentary basin centered between both branches of the EARS and located in the interior of the East African Plateau (EAP). We quantify the fluvial catchment evolution of the Lake Victoria basin and assess the topographic response of African crust to the onset of rifting in both branches. Furthermore, we evaluate and localize the nature of strain and flexural rift-flank uplift in both branches. We use a 3D numerical forward model that includes nonlinear temperature- and stress-dependent elasto-visco-plastic rheology. The model is able to reproduce the flexural response of variably thick lithosphere to rift-related deformation processes such as lithospheric thinning and asthenospheric upwelling. The model domain covers the entire EAP and integrates extensional processes in a heterogeneous, yet cold and thick cratonic block (Archean Tanzania craton), which is surrounded by mechanically weaker Proterozoic mobile belts, which are characterized by thinner lithosphere ("thin spots"). The lower limits of the craton (170 km) and the mobile belts (120 km) are simulated by different depths of the 1300 °C lithosphere-asthenosphere boundary. We assume a constant extension rate of 4 mm/a throughout the entire simulation of 30 Ma and neglect the effect of dynamic topography and magmatism. Even though the model setup is very simple and the resolution is not high enough to calculate realistic rift-flank uplift, it intriguingly reveals important topographic
NASA Astrophysics Data System (ADS)
Oteng, F. M.; Yidana, S. M.; Alo, C. A.
2012-12-01
Effective development and informed management of groundwater resources represent a critical opportunity for improved rural water supply in Ghana and enhanced livelihoods particularly in the northern part of the White Volta Basin, a region already prone to a myriad of water-related infirmities. If adequately developed, the resource will form a sufficient buffer against the effects of climate change/variability and foster food security and sustainable livelihoods among the largely peasant communities in the region. This research presents the results of a preliminary assessment of the hydrogeological conditions and recharge regimes of the aquifers in the Northern parts of the White Volta Basin, Ghana. Results of estimates of groundwater recharge through the conventional isotopic and mass balance techniques are presented. Details of the groundwater flow pattern and preliminary delineation of local and regional groundwater recharge areas are presented from initial simulations of the hydrogeological system with a robust groundwater flow simulation code, MODFLOW, in the Groundwater Modeling System, GMS, version 7.1. The stream flow and evapotranspiration components of the program were activated to incorporate surface flow processes, so that the resulting model represents the conditions of the entire hydrological system. The results of this study form a platform for detailed numerical assessment of the conditions of the aquifers in the area under transient conditions of fluctuating rainfall patterns in the face of climate change/variability.
NASA Astrophysics Data System (ADS)
Li, Lu; Qiu, Nansheng
2017-06-01
In this study the dynamic aspects of the Cenozoic extension in the Bohai Bay Basin are considered in the context of initial thickness of the crust and lithosphere, tectonic force, strain rate and thermal rheology, which are directly or indirectly estimated from a pure shear extensional model. It is accordingly reasonable to expect that, in the Bohai Bay Basin, the thickness variation could be present prior to the initiation of extension. The extensional deformation is localized by a thickness variation of the crust and lithosphere and the heterogeneity of the initial thickness plays an important role in rifting dynamics. The onset of rifting requires a critical tectonic force (initial tectonic force) to be applied, which then immediately begins to decay gradually. Rifting will only occur when the total effective buoyancy force of the subducting slab reaches a critical level, after a certain amount of subduction taking place. The magnitude of the tectonic force decreases with time in the early phase of rifting, which indicates the weakening due to the increase in geothermal gradient. In order to deform the continental lithosphere within the currently accepted maximum magnitude of the force derived from subducted slab roll-back, the following conditions should be satisfied: (1) the thickness of the continental lithosphere is significantly thin and less than 125 km and (2) the lithosphere has a wet and hot rheology, which provides implications for rheological layering in continental lithosphere. Our results are strongly supported by the ;crème brûlée; model, in which the lower crust and mantle are relatively ductile.
Tectonic Subsidence Analysis of the Pearl River Mouth Basin, Northern South China Sea
NASA Astrophysics Data System (ADS)
Tang, X.; Huang, S. S. X. E. C.; Zhuang, W.; LIU, Z.; Duan, W.; Hu, S.
2015-12-01
The Pearl River Mouth Basin (PRMB hereafter) in the northern margin of the South China Sea has attracted great attention not only because of its special tectonic location but also for its abundant hydrocarbon resources. Tectonic evolution controls the petroleum geological condition of hydrocarbon-bearing basins. Efforts have been made to understand the tectonic evolution of this basin. However, many issues about the tectonic features and the evolution process of this basin, such as the age of the breakup unconformities and the anomalously accelerated subsidence during the post-rifting stage, remain controversial. Here we employ tectonic subsidence analysis of sedimentary basins, a technique of removing isostatic loading and compaction effects by back-stripping, to investigate the tectonic controls on the basin formation of the PRMB. We performed the analysis on 4 drill wells and 43 synthetic wells constructed based on recently acquired seismic profiles. The result shows that tectonic subsidence in the eastern sags of the PRMB began to decrease at ~30Ma while in the western sags the onset was ~23.8Ma. This suggests that the break-up time i.e. the end of rifting in the PRMB is earlier in the eastern sags than in the western sags. Abnormally accelerated tectonic subsidence occurred between 17.5-16.4Ma during the post-rifting stage, at an average subsidence rate as high as 301.9m/Ma. This phenomenon discriminates the PRMB from the category of classical Atlantic passive continental marginal basins, of which the tectonic subsidence during the post-rifting stage decays exponentially. The main objective of this paper is to provide insights into the geological and geodynamic evolution of the PRMB. The result bears significance to hydrocarbon exploration in this region.
Method Study of Flood Hazard Analysis for Plain River Network Area, Taihu Basin, China
NASA Astrophysics Data System (ADS)
HAN, C.; Liu, S.; Zhong, G.; Zhang, X.
2015-12-01
Flood is one of the most common and serious natural calamities. Taihu Basin is located in delta region of the Yangtze River in East China (see Fig. 1). Because of the abundant rainfall and low-lying terrain, the area frequently suffers from flood hazard which have caused serious casualty and economic loss. In order to reduce the severe impacts of floods events, numerous polder areas and hydraulic constructions (including pumps, water gates etc.) were constructed. Flood Hazard Map is an effective non-structural flood mitigation tool measures. Numerical simulation of flood propagation is one of the key technologies of flood hazard mapping. Because of the complexity of its underlying surface characteristics, numerical simulation of flood propagation was faced with some special problems for the plain river network area in Taihu Basin. In this paper, a coupled one and two dimensional hydrodynamic model was established. Densely covered and interconnected river networks, numerous polder areas and complex scheduling hydraulic constructions were generalized in the model. The model was proved to be believable and stable. Based on the results of the simulation of flood propagation, flood hazard map was compiled.
Quantitative analysis of numerical solvers for oscillatory biomolecular system models
Quo, Chang F; Wang, May D
2008-01-01
Background This article provides guidelines for selecting optimal numerical solvers for biomolecular system models. Because various parameters of the same system could have drastically different ranges from 10-15 to 1010, the ODEs can be stiff and ill-conditioned, resulting in non-unique, non-existing, or non-reproducible modeling solutions. Previous studies have not examined in depth how to best select numerical solvers for biomolecular system models, which makes it difficult to experimentally validate the modeling results. To address this problem, we have chosen one of the well-known stiff initial value problems with limit cycle behavior as a test-bed system model. Solving this model, we have illustrated that different answers may result from different numerical solvers. We use MATLAB numerical solvers because they are optimized and widely used by the modeling community. We have also conducted a systematic study of numerical solver performances by using qualitative and quantitative measures such as convergence, accuracy, and computational cost (i.e. in terms of function evaluation, partial derivative, LU decomposition, and "take-off" points). The results show that the modeling solutions can be drastically different using different numerical solvers. Thus, it is important to intelligently select numerical solvers when solving biomolecular system models. Results The classic Belousov-Zhabotinskii (BZ) reaction is described by the Oregonator model and is used as a case study. We report two guidelines in selecting optimal numerical solver(s) for stiff, complex oscillatory systems: (i) for problems with unknown parameters, ode45 is the optimal choice regardless of the relative error tolerance; (ii) for known stiff problems, both ode113 and ode15s are good choices under strict relative tolerance conditions. Conclusions For any given biomolecular model, by building a library of numerical solvers with quantitative performance assessment metric, we show that it is possible
Drought analysis in the Tons River Basin, India during 1969-2008
NASA Astrophysics Data System (ADS)
Meshram, Sarita Gajbhiye; Gautam, Randhir; Kahya, Ercan
2017-05-01
The primary focus of this study is the analysis of droughts in the Tons River Basin during the period 1969-2008. Precipitation data observed at four gauging stations are used to identify drought over the study area. The event of drought is derived from the standardized precipitation index (SPI) on a 3-month scale. Our results indicated that severe drought occurred in the Allahabad, Rewa, and Satna stations in the years 1973 and 1979. The droughts in this region had occurred mainly due to erratic behavior in monsoons, especially due to long breaks between monsoons. During the drought years, the deficiency of the annual rainfall in the analysis of annual rainfall departure had varied from -26% in 1976 to -60% in 1973 at Allahabad station in the basin. The maximum deficiency of annual and seasonal rainfall recorded in the basin is 60%. The maximum seasonal rainfall departure observed in the basin is in the order of -60% at Allahabad station in 1973, while maximum annual rainfall departure had been recorded as -60% during 1979 at the Satna station. Extreme dry events (z score <-2) were detected during July, August, and September. Moreover, severe dry events were observed in August, September, and October. The drought conditions in the Tons River Basin are dominantly driven by total rainfall throughout the period between June and November.
NASA Astrophysics Data System (ADS)
Lagmay, A. M. F.; Tengonciang, A. M. P.; Uy, H. S.
2005-06-01
Mayon Volcano is located within the Bicol Basin in the southeastern region of Luzon, Philippines. The basin is contained within a releasing bend associated with the curvature of the central segment of the left-lateral Philippine Fault. A structural analysis of the faults that traverse the Bicol Basin was conducted through reviews of existing literature, seismic data interpretation, and remote sensing; in particular, those structures that may have influenced the growth and evolution of Mayon. Dynamic analysis of the aforementioned structures reveals a regional transtensional stress regime for the Bicol Basin. Field investigation on Mayon's slopes revealed the existence of fractures along its western and eastern flanks. These structures on Mayon have the same geometry as the dominant faults found within the Bicol Basin. Interpretation of these fractures indicates a tectonic control over their origin. The identification of fractures on Mayon's slopes is the first description of such features on its edifice. These new data highlight the probable landslide hazards associated with an oversteepened volcano that may have been further destabilized by tectonic activity.
Numeric Program Analysis Techniques with Applications to Array Analysis and Library Summarization
2007-01-01
specific sets of programs and/or properties, has been designed . Conceptually, a program analyzer consists of two components: (i) an abstract domain, ap...modular design provides for program -analysis implementations that are parametrized by an ab- stract domain: as more sophisticated abstractions are designed ...numeric program analysis. 1.4.1 Contributions at a Glance This thesis makes the following contributions: • Summarizing abstractions [47]. We design a
Numerical analysis for comparison of aerodynamic characteristics of six airfoils
NASA Astrophysics Data System (ADS)
Saad, Magedi Moh M.; Mohd, Sofian Bin; Zulkafli, Mohd Fadhli; Shibani, Wanis Mustafa E.
2017-04-01
Comparison of six airfoils; FX 63-137, FX76-100, S835, S809, NACA63415, and NACA63215, have been performed using commercial software, FLUENT and XFOIL, in order to choose the best maximum lift to drag ratio in the region of 4×10∧6 Reynolds number, and also to specify their aerodynamic coefficients in Blade Element Momentum theory (BEM). These airfoils are candidates for the use as blade turbines and another application of flying object operating at high Reynolds number. In this study, the two-dimensional model of airfoils was established through Gambit software. The range of angles of attack is from -150 to 150. Comparisons of the numerical results generally show good agreements. Numerical results of FX 63-137 were also validated with experimental data. A good agreement of lift and drag coefficient from numerical simulations of FLUENT and experimental data was obtained at 10∧6 Reynolds number.
Water Level Temporal Variation Analysis at Prata Basin Using GRACE
NASA Astrophysics Data System (ADS)
Guimaraes, G.; Blitzkow, D.; Matos, A.; Vaz, F.; Campos, I.; Barbosa, A.
2008-12-01
A comparison between daily in-situ water level time series measured at ground-based hydrometric stations of Agência Nacional de Águas (ANA) with vertically-integrated water height deduced from GRACE geoid (height anomaly) is carried out. The 10-day intervals of GRACE models were computed by Groupe de Recherches de Géodésie Spatiale (CNES/GRGS). The height anomaly was converted into equivalent water height, over the Prata basin for a ~6-year period (July-2002 to May-2008). A correlation around 74 per cent has been detected. This correlation allows defining a local transfer function by adjusting a linear relationship between GRACE-based and in situ observation time-series. The study of the Continuous Wavelet Transform was applied in the hydrometric stations and a time-scale correlation was figured out.
Structural analysis of high-dimensional basins of attraction.
Martiniani, Stefano; Schrenk, K Julian; Stevenson, Jacob D; Wales, David J; Frenkel, Daan
2016-09-01
We propose an efficient Monte Carlo method for the computation of the volumes of high-dimensional bodies with arbitrary shape. We start with a region of known volume within the interior of the manifold and then use the multistate Bennett acceptance-ratio method to compute the dimensionless free-energy difference between a series of equilibrium simulations performed within this object. The method produces results that are in excellent agreement with thermodynamic integration, as well as a direct estimate of the associated statistical uncertainties. The histogram method also allows us to directly obtain an estimate of the interior radial probability density profile, thus yielding useful insight into the structural properties of such a high-dimensional body. We illustrate the method by analyzing the effect of structural disorder on the basins of attraction of mechanically stable packings of soft repulsive spheres.
Effective numerical method of spectral analysis of quantum graphs
NASA Astrophysics Data System (ADS)
Barrera-Figueroa, Víctor; Rabinovich, Vladimir S.
2017-05-01
We present in the paper an effective numerical method for the determination of the spectra of periodic metric graphs equipped by Schrödinger operators with real-valued periodic electric potentials as Hamiltonians and with Kirchhoff and Neumann conditions at the vertices. Our method is based on the spectral parameter power series method, which leads to a series representation of the dispersion equation, which is suitable for both analytical and numerical calculations. Several important examples demonstrate the effectiveness of our method for some periodic graphs of interest that possess potentials usually found in quantum mechanics.
Analysis of anelastic flow and numerical treatment via finite elements
Martinez, M.J.
1994-05-01
In this report, we reconsider the various approximations made to the full equations of motion and energy transport for treating low-speed flows with significant temperature induced property variations. This entails assessment of the development of so-called anelastic for low-Mach number flows outside the range of validity of the Boussinesq equations. An integral part of this assessment is the development of a finite element-based numerical scheme for obtaining approximate numerical solutions to this class of problems. Several formulations were attempted and are compared.
A spatial analysis of phosphorus in the Mississippi river basin.
Jacobson, Linda M; David, Mark B; Drinkwater, Laurie E
2011-01-01
Phosphorus (P) in rivers in the Mississippi River basin (MRB) contributes to hypoxia in the Gulf of Mexico and impairs local water quality. We analyzed the spatial pattern of P in the MRB to determine the counties with the greatest January to June P riverine yields and the most critical factors related to this P loss. Using a database of P inputs and landscape characteristics from 1997 through 2006 for each county in the MRB, we created regression models relating riverine total P (TP), dissolved reactive P (DRP), and particulate P (PP) yields for watersheds within the MRB to these factors. Riverine yields of P were estimated from the average concentration of each form of P during January to June for the 10-yr period, multiplied by the average daily flow, and then summed for the 6-mo period. The fraction of land planted in crops, human consumption of P, and precipitation were found to best predict TP yields with a spatial error regression model ( = 0.48, = 101). Dissolved reactive P yields were predicted by fertilizer P inputs, human consumption of P, and precipitation in a multiple regression model ( = 0.42, = 73), whereas PP yields were explained by crop fraction, human consumption of P, and soil bulk density in a spatial error regression model ( = 0.49, = 61). Overall, the Upper Midwest's Cornbelt region and lower Mississippi basin had the counties with the greatest P yields. These results help to point out specific areas where agricultural conservation practices that reduce losses to streams and rivers and point source P removal might limit the intensity or spatial occurrence of Gulf of Mexico hypoxia and improve local water quality. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.
NASA Astrophysics Data System (ADS)
Dadashzadeh, N.; Duzgun, H. S. B.; Yesiloglu-Gultekin, N.
2017-08-01
While advanced numerical techniques in slope stability analysis are successfully used in deterministic studies, they have so far found limited use in probabilistic analyses due to their high computation cost. The first-order reliability method (FORM) is one of the most efficient probabilistic techniques to perform probabilistic stability analysis by considering the associated uncertainties in the analysis parameters. However, it is not possible to directly use FORM in numerical slope stability evaluations as it requires definition of a limit state performance function. In this study, an integrated methodology for probabilistic numerical modeling of rock slope stability is proposed. The methodology is based on response surface method, where FORM is used to develop an explicit performance function from the results of numerical simulations. The implementation of the proposed methodology is performed by considering a large potential rock wedge in Sumela Monastery, Turkey. The accuracy of the developed performance function to truly represent the limit state surface is evaluated by monitoring the slope behavior. The calculated probability of failure is compared with Monte Carlo simulation (MCS) method. The proposed methodology is found to be 72% more efficient than MCS, while the accuracy is decreased with an error of 24%.
Evaluation of the oil spill risk analysis as presented in St. George Basin Sale 89 EIS
Not Available
1985-05-31
The report describes and evaluates the current approach to the oil-spill risk analysis as conducted for St. George Basin Sale 89. An oil spill trajectory analysis (OTSA) model was developed for the U.S. Minerals Management Service to calculate the risk of oil spills damaging environmentally sensitive resources. The purpose of the report is to review the Minerals Management Service oil-spill risk analysis as presented in the Lease Sale 89 EIS.
Numerical Analysis of Turbulent Flows in Channels of Complex Geometry
NASA Astrophysics Data System (ADS)
Farbos De Luzan, Charles
The current study proposes to follow a systematic validated approach to applied fluid mechanics problems in order to evaluate the ability of different computational fluid dynamics (CFD) to be a relevant design tool. This systematic approach involves different operations such as grid sensitivity analyses, turbulence models comparison and appropriate wall treatments, in order to define case-specific optimal parameters for industrial applications. A validation effort is performed on each study, with particle image velocimetry (PIV) experimental results as the validating metric. The first part of the dissertation lays down the principles of validation, and presents the details of a grid sensitivity analysis, as well as a turbulence models benchmark. The models are available in commercial solvers, and in most cases the default values of the equations constants are retained. The validation experimental data is taken with a hot wire, and has served as a reference to validate multiple turbulence models for turbulent flows in channels. In a second part, the study of a coaxial piping system will compare a set of different steady Reynolds-Averaged Navier Stokes (RANS) turbulence models, namely the one equation model Spalart-Almaras, and two-equation-models standard k-epsilon, k-epsilon realizable, k-epsilon RNG, standard k-omega, k-omega SST, and transition SST. The geometry of interest involves a transition from an annulus into a larger one, where highly turbulent phenomena occur, such as recirculation and jet impingement. Based on a set of constraints that are defined in the analysis, a chosen model will be tested on new designs in order to evaluate their performance. The third part of this dissertation will address the steady-state flow patterns in a Viscosity-Sensitive Fluidic Diode (VSFD). This device is used in a fluidics application, and its originality lies in the fact that it does not require a control fluid in order to operate. This section will discuss the
Numerical analysis of initial stage of thermal shock
NASA Astrophysics Data System (ADS)
Demidov, V. N.
2016-07-01
The paper studies a problem of a thermal shock at the surface of a half-space, which properties are described by elastic-plastic model taking into account dynamic effects, heat inertia, coupling between thermal and mechanical fields. The problem is solved numerically using finite-difference method of S.K. Godunov.
Numerical analysis of Ostwald ripening in two-dimensional systems.
Dubrovskii, V G; Kazansky, M A; Nazarenko, M V; Adzhemyan, L T
2011-03-07
This work addresses theory of Ostwald ripening based on the continuum second order kinetic equation for the size distribution of embryos over sizes. Numerical studies are performed with two-dimensional condensing systems having different growth laws of islands, using different forms of kinetic equation. The material influx into the system is terminated to enable the Ostwald ripening process. We obtain numerical solutions for the size distributions with and without fluctuation effects described by the second derivative in the kinetic equation. We show that fluctuations lead to a considerable broadening of size distribution at the early Ostwald ripening step in the diffusion limited growth of islands. Comparison of our numerical distributions with the deterministic Lifshitz-Slezov shape shows that the latter in principle withstands fluctuations. However, the correspondence between the numerical large time asymptotes and the Lifshitz-Slezov spectra is not perfect, particularly in the diffusion-induced growth regime, and becomes worse when the fluctuations are included. © 2011 American Institute of Physics.
Analysis and Modeling of Buoyancy Generated Turbulence using Numerical Data.
1997-09-01
Rayleigh- Bernard convection offers a unique flow situation in which buoyancy-generated turbulence can be studied in isolation, free of the...using direct numerical simulation (DNS) data of Rayleigh- Bernard convection. In particular, we examine the pressure-strain and pressure temperature
Approximation and Numerical Analysis of Nonlinear Equations of Evolution.
1980-01-31
les Espaces d’ Interpolation; Dualitg", Math. Scand., 9, 1961, pp. 147-177. 9. __ "Equations Diff~rentielles Op ~ rationnelles dan les Espaces de Hilbert...relaxation," Revue Francaise d’automatique, informatique, recherche operationnelle, R3, 1973, p. 5-32. Ill DOUGLAS, J. and GALLIE, T.MI. "On the Numerical
NASA Astrophysics Data System (ADS)
Xie, Wen-Jie; Jiang, Zhi-Qiang; Gu, Gao-Feng; Xiong, Xiong; Zhou, Wei-Xing
2015-10-01
Many complex systems generate multifractal time series which are long-range cross-correlated. Numerous methods have been proposed to characterize the multifractal nature of these long-range cross correlations. However, several important issues about these methods are not well understood and most methods consider only one moment order. We study the joint multifractal analysis based on partition function with two moment orders, which was initially invented to investigate fluid fields, and derive analytically several important properties. We apply the method numerically to binomial measures with multifractal cross correlations and bivariate fractional Brownian motions without multifractal cross correlations. For binomial multifractal measures, the explicit expressions of mass function, singularity strength and multifractal spectrum of the cross correlations are derived, which agree excellently with the numerical results. We also apply the method to stock market indexes and unveil intriguing multifractality in the cross correlations of index volatilities.
Jones, Joseph L.; Johnson, Kenneth H.; Frans, Lonna M.
2013-01-01
A groundwater-flow model was developed to evaluate potential future effects of growth and of water-management strategies on water resources in the Chimacum Creek Basin. The model covers an area of about 64 square miles (mi2) on the Olympic Peninsula in northeastern Jefferson County, Washington. The Chimacum Creek Basin drains an area of about 53 mi2 and consists of Chimacum Creek and its tributary East Fork Chimacum Creek, which converge near the town of Chimacum and discharge to Port Townsend Bay near the town of Irondale. The topography of the model area consists of north-south oriented, narrow, regularly spaced parallel ridges and valleys that are characteristic of fluted glaciated surfaces. Thick accumulations of peat occur along the axis of East Fork Chimacum Creek and provide rich soils for agricultural use. The study area is underlain by a north-thickening sequence of unconsolidated glacial (till and outwash) and interglacial (fluvial and lacustrine) deposits, and sedimentary and igneous bedrock units that crop out along the margins and the western interior of the model area. Six hydrogeologic units in the model area form the basis of the groundwater-flow model. They are represented by model layers UC (upper confining), UA (upper aquifer), MC (middle confining), LA (lower aquifer), LC (lower confining), and OE (bedrock). Groundwater flow in the Chimacum Creek Basin and vicinity was simulated using the groundwater-flow model, MODFLOW-2005. The finite-difference model grid comprises 245 columns, 313 rows, and 6 layers. Each model cell has a horizontal dimension of 200 × 200 feet (ft). The thickness of model layers varies throughout the model area and ranges from 5 ft in the non-bedrock units to more than 2,400 ft in the bedrock. Groundwater flow was simulated for steady-state conditions, which were simulated for calibration of the model using average recharge, discharge, and water levels for the 180-month period October 1994–September 2009. The model as
NASA Astrophysics Data System (ADS)
Gamboa, Davide; Williams, John; Kirk, Karen; Gent, Christopher; Bentham, Michelle; Fellgett, Mark; Schofield, David
2016-04-01
Carbon Capture and Storage (CCS) is a vital technology towards low-carbon energy resources and the mitigation of global warming trends induced by rising CO2 levels in the atmosphere. The East Irish Sea Basin (EISB) is a key area for CCS in the western UK, having high CO2 storage potentials in explored hydrocarbon fields and in saline aquifers within the Permo-Triassic Sherwood Sandstone Formation. However, the theoretical storage potential of the EISB could be poorly estimated as the reservoir-prone Lower Permian formations are not considered in detail by current estimations. This work aims to fill this gap, focusing on the characterisation of the Lower Permian Collyhurst Sandstone Formation as a viable storage unit. The potential for CO2 storage is estimated as the total volume/area of suitable closures that are isolated by structural traps, occurring at depths suitable for CO2 injection and containment (>800m). Detailed structural and stratigraphic interpretations were made using 3D seismic data to assess the storage potential of the Collyhurst Sandstone Formation in the southern EISB. The basin strata is compartmentalised by numerous N-S trending faults. A higher degree of compartmentalisation occurs within regional anticlines where elongated tilted blocks are observed, bound by predominantly west-dipping faults that induce a variable offset of the Collyhurst Sandstone strata. Contrastingly, higher lateral continuity of this formation is observed within graben basins were faults are less frequent and with minor offset, thus potentially creating larger storage closures. Fault dip orientation in the grabens is variable, with west and east dipping faults occurring as a function of large east-dipping listric faults. This study was complemented by the stress modelling of the interpreted faults in order to assess the risk of CO2 leakage. Analysis of borehole breakouts observed in four approximately vertical wells in the EISB suggest a maximum horizontal stress
The numerical analysis of a turbulent compressible jet
NASA Astrophysics Data System (ADS)
Debonis, James Raymond
2000-10-01
A numerical method to simulate high Reynolds number jet flows was formulated and applied to gain a better understanding of the flow physics. Large-eddy simulation was chosen as the most promising approach to model the turbulent structures due to its compromise between accuracy and computational expense. The filtered Navier-Stokes equations were developed including a total energy form of the energy equation. Sub-grid scale models for the momentum and energy equations were adapted from compressible forms of Smagorinsky's original model. The effect of using disparate temporal and spatial accuracy in a numerical scheme was discovered through one-dimensional model problems and a new uniformly fourth-order accurate numerical method was developed. Results from two and three dimensional validation exercises show that the code accurately reproduces both viscous and inviscid flows. Numerous axisymmetric jet simulations were performed to investigate the effect of grid resolution, numerical scheme, exit boundary conditions and sub-grid scale modeling on the solution and the results were used to guide the three-dimensional calculations. Three-dimensional calculations of a Mach 1.4 jet showed that this LES simulation accurately captures the physics of the turbulent flow. The agreement with experimental data relatively good and is much better than results in the current literature. Turbulent intensities indicate that the turbulent structures at this level of modeling are not isotropic and this information could lend itself to the development of improved sub-grid scale models for LES and turbulence models for RANS simulations. A two point correlation technique was used to quantify the turbulent structures. Two point space correlations were used to obtain a measure of the integral length scale, which proved to be approximately ½Dj. Two point space-time correlations were used to obtain the convection velocity for the turbulent structures. This velocity ranged from 0.57 to 0.71 Uj.
Preliminary analysis of ERTS-relayed water resources data in the Delaware River Basin
NASA Technical Reports Server (NTRS)
Paulson, R. W.
1973-01-01
Preliminary analysis of ERTS-DCS data from water-resources stations in the Delaware River Basin indicates that the Data-Collection System is performing well. Data-Collections Platforms have been successfully interfaced with five stream-gaging station and three ground-water observation wells and are being interfaced with 12 water-quality monitors in the basin. Data are being relayed during four or five ERTS orbital passes per day, which is within the design specifications of the ERTS-DCS.
1980-11-01
Certain considerations in the depressional storage and drainage phase are available which act as a type of storage routing technique by virtue of the depth...AD-Al-35 697 ANALYSS SOF EXISTING HYDROL00IC MODELS RED RIVER OF THE I/ H MLAEEW NVR DAW 79CDNORTH DRAINAGE BASIN NORTH DAKOTA AND MINNESOTANU) CH2M...Corps of Engineers LO I Analysis of Existing Hydrologic Models, Red River of the North Drainage Basin North Dakota and Minnesota CH2M IHILL OEG3’U 6~A
NASA Astrophysics Data System (ADS)
Chang, Hsiao-Tung
2016-06-01
Urban Heat Island (UHI) has been becoming a key factor in deteriorating the urban ecological environment. Spatial-temporal analysis on its prototype of basin city's UHI and quantitatively evaluating effect from rapid urbanization will provide theoretical foundation for relieving UHI effect. Based on Landsat 8, ETM+ and TM images of Taipei basin areas from 1900 to 2015, this article has retrieved the land surface temperature (LST) at summer solstice of each year, and then analysed spatial-temporal pattern and evolution characters of UHI in Taipei basin in this decade. The results showed that the expansion built district, UHI area constantly expanded from centre city to the suburb areas. The prototype of UHI in Taipei basin that showed in addition to higher temperatures in the centre city also were relatively high temperatures gathered boundaries surrounded by foot of mountains side. It calls "sinking heat island". From 1900 to 2000, the higher UHI areas were different land use type change had obvious difference by public infrastructure works. And then, in next 15 years till 2015, building density of urban area has been increasing gradually. It has the trend that UHI flooding raises follow urban land use density. Hot spot of UHI in Taipei basin also has the same characteristics. The results suggest that anthropogenic heat release probably plays a significant role in the UHI effect, and must be considered in urban planning adaptation strategies.
Howell, P.D.; Budai, J.M.
1989-03-01
Quantitative paleobathymetry is difficult to determine for any rock sequence with a significant subtidal component. Water depth estimates are traditionally obtained from detailed sedimentology and paleontology, but this type of data is seldom available in subsurface work. Further, a good geological data base may be inconclusive for paleobathymetry in subtidal or substorm-wave base environments. More accurate facies prediction would be possible if paleobathymetry could be determined from the conventional subsurface data normally available to explorationists. Subsidence analysis of sedimentary basins has the potential to provide precise paleobathymetric estimates for a variety of depositional settings. This technique is illustrated using the Middle Ordovician carbonates of the Michigan basin. Tectonic subsidence patterns established from stratigraphic and subsidence modeling of the Lower-Middle Ordovician Prairie du Chien Group in Michigan are projected forward through the Middle Ordovician. Isopach thicknesses of the Black River and Trenton carbonates are superimposed on the tectonic subsidence patterns to provide a quantitative basin-fill model. The model paleobathymetry is then compared with core data from exploration wells to evaluate the model facies interpretation. An excellent fit is achieved for the shallow to deep subtidal platform and basinal Trenton carbonates. This technique allows paleobathymetry to be calculated in many basins where tectonic subsidence patterns can be accurately modeled.
NASA Technical Reports Server (NTRS)
Bowman, Kenneth P.; Sacks, Jerome; Chang, Yue-Fang
1993-01-01
Methods for the design and analysis of numerical experiments that are especially useful and efficient in multidimensional parameter spaces are presented. The analysis method, which is similar to kriging in the spatial analysis literature, fits a statistical model to the output of the numerical model. The method is applied to a fully nonlinear, global, equivalent-barotropic dynamical model. The statistical model also provides estimates for the uncertainty of predicted numerical model output, which can provide guidance on where in the parameter space to conduct further experiments, if necessary. The method can provide significant improvements in the efficiency with which numerical sensitivity experiments are conducted.
NASA Astrophysics Data System (ADS)
Bartholy, Judit; Pongrácz, Rita; Molnár, Zsófia
2004-11-01
In order to cover a millennium-long period in climatological studies, several types of information must be taken into consideration. Beyond the regular meteorological observations, historical documentary data may serve as a basic source for the past centuries. For the Carpathian basin, Réthly collected historical documents containing meteorology-related information. In order to facilitate the analysis of this documentary collection, a special code system using hierarchical subclasses has been defined and applied to approximately 15 000 collected climatological items. The spatial and temporal distributions of temperature- and precipitation-related climate events and extremes have been evaluated using settlement and subregional scales. Also, the geographical distribution of extreme climatological events has been mapped. Annual and seasonal time series have been analysed for the Carpathian basin and compared with other reconstructed temperature and precipitation index time series from other geographical locations outside the Carpathian basin.
Paleocurrent analysis of a deformed Devonian foreland basin in the northern Appalachians, Maine, USA
Bradley, D.C.; Hanson, L.S.
2002-01-01
New paleocurrent data indicate that the widespread Late Silurian and Devonian flysch and molasse succession in Maine was deposited in an ancestral, migrating foreland basin adjacent to an advancing Acadian orogenic belt. The foreland-basin sequence spread across a varied Silurian paleogeography of deep basins and small islands-the vestiges of an intraoceanic arc complex that not long before had collided with the Laurentian passive margin during the Ordovician Taconic Orogeny. We report paleocurrents from 43 sites representing 12 stratigraphic units, the most robust and consistent results coming from three units: Madrid Formation (southwesterly paleoflow), Carrabassett Formation (northerly paleoflow), and Seboomook Group (westerly paleoflow). Deformation and regional metamorphism are sufficiently intense to test the limits of paleocurrent analysis requiring particular care in retrodeformation. ?? 2002 Elsevier Science B.V. All rights reserved.
Wu, Feifei; Wang, Xuan; Cai, Yanpeng; Yang, Zhifeng; Li, Chunhui
2012-06-15
Occurrence of temperature anomaly has greatly affected natural cycles of water resources in Lancang River basin in China, which is the upper reach of Mekong River. An integrated spatiotemporal decomposition and analysis method was proposed for the identification of temperature-variation patterns under changing climatic conditions in the basin. This method was based on the combination of S-mode empirical orthogonal function analysis, IDW interpolation, liner regression, weighted moving average and Mann Kendall methods. Results indicated that the first two modes extracted nearly 80% of spatiotemporal variations in temperature. Temperature in the whole basin followed the same variation trend through the first mode analysis. Sensitive areas were mainly located in the southwest of the basin, which occupied nearly half of the basin. The associated time series presented that the basin appeared transition from cold periods to warm periods. Temperature increased significantly over the period of 1960 to 2009 at annual and seasonal scales, particularly over 1990s. At the same time, the most significant rising occurred in winter and the least in summer. In the second mode, a west-east inverse phase pattern of temperature variations was a distinct feature in most of the basin. Temporal trend indicated that the increasing trend in the west region was slightly stronger than that in the east. This was particularly the case of edge areas almost vertical juncture with monsoons. This research is not only helpful in improving understanding of temperature response to global warming in the basin but also provides a basis for basin management.
Analysis of future precipitation in the Koshi river basin, Nepal
NASA Astrophysics Data System (ADS)
Agarwal, Anshul; Babel, Mukand S.; Maskey, Shreedhar
2014-05-01
We analyzed precipitation projections for the Koshi river basin in Nepal using outputs from 10 General Circulation Models (GCMs) under three emission scenarios (B1, A1B and A2). The low resolution future precipitation data obtained from the GCMs was downscaled using the statistical downscaling model LARS-WG. The data was downscaled for 48 stations located in the six physiographic regions in the Koshi basin. The precipitation projections for three future periods, i.e. 2020s, 2055s and 2090s, are presented using empirical Probability Density Functions (PDFs) for each physiographic region. The differences between the mean values of individual GCM projections and the mean value of the multi-model for the three scenarios allow for the estimation of uncertainty in the projections. We also analyzed the precipitation of the baseline and future periods using six indices that are recommended by the Expert Team on Climate Change Detection, Monitoring and Indices (ETCCDMI). Results indicate that not all GCMs agree on weather changes in precipitation will be positive or negative. A majority of the GCMs and the average values of all the GCMs for each scenario, indicate a positive change in summer, autumn and annual precipitation but a negative change in spring precipitation. Differences in the GCM projections exist for all the three future periods and the differences increase with time. The estimated uncertainty is higher for scenario A1B compared to B1 and A2. Differences among scenarios are small during the 2020s, which become significant during the 2055s and 2090s. The length of the wet spell is expected to increase, whereas the length of the dry spell is expected to decrease in all three future periods. There is a large scatter in the values of the indices: number of days with precipitation above 20 mm, 1-day maximum precipitation, 5-day maximum precipitation, and amount of precipitation on the days with precipitation above 95th percentile, both in direction and magnitude of
FUTURE WATER ALLOCATION AND IN-STREAM VALUES IN THE WILLAMETTE RIVER BASIN: A BASIN-WIDE ANALYSIS
Our research investigated the impact on surface water resources of three different scenarios for the future development of the Willamette River Basin in Oregon (USA). Water rights in the basin, and in the western United States in general, are based on a system of law that binds ...
FUTURE WATER ALLOCATION AND IN-STREAM VALUES IN THE WILLAMETTE RIVER BASIN: A BASIN-WIDE ANALYSIS
Our research investigated the impact on surface water resources of three different scenarios for the future development of the Willamette River Basin in Oregon (USA). Water rights in the basin, and in the western United States in general, are based on a system of law that binds ...
Numerical analysis of supersonic combustion ramjet with upstream fuel injection
NASA Astrophysics Data System (ADS)
Savino, Raffaele; Pezzella, Giuseppe
2003-09-01
This paper describes possible fuel injection scheme for airbreathing engines that use hydrocarbon fuels. The basic idea is to inject fuel at the spike tip of the supersonic inlet to achieve mixing and combustion efficiency with a limited length combustion chamber. A numerical code, able to solve the full Navier-Stokes equations in turbulent and reacting flows, is employed to obtain numerical simulations of the thermo-fluidynamic fields at different scramjet flight conditions, at Mach numbers of M=6.5 and 8. The feasibility of the idea of the upstream injection is checked for a simple axisymmetric configuration and relatively small size. The results are discussed in connection with the potential benefits deriving from the use of new ultra high temperature ceramics (UHTC).
An efficient numerical procedure for thermohydrodynamic analysis of cavitating bearings
NASA Technical Reports Server (NTRS)
Vijayaraghavan, D.
1995-01-01
An efficient and accurate numerical procedure to determine the thermo-hydrodynamic performance of cavitating bearings is described. This procedure is based on the earlier development of Elrod for lubricating films, in which the properties across the film thickness are determined at Lobatto points and their distributions are expressed by collocated polynomials. The cavitated regions and their boundaries are rigorously treated. Thermal boundary conditions at the surfaces, including heat dissipation through the metal to the ambient, are incorporated. Numerical examples are presented comparing the predictions using this procedure with earlier theoretical predictions and experimental data. With a few points across the film thickness and across the journal and the bearing in the radial direction, the temperature profile is very well predicted.
Nonlinear ultrasonic resonators: a numerical analysis in the time domain.
Vanhille, Christian; Campos-Pozuelo, Cleofé
2006-12-22
In the framework of the study of nonlinear acoustic phenomena arising in high-power ultrasonic resonators, this paper deals with the numerical prediction of the behaviour of strongly nonlinear waves in resonators. In particular three-dimensional cavities in complex modal configurations are analyzed. The main motivation of this work is the understanding and optimisation of high-power ultrasonic applications in fluids. Based on conservation laws written in Lagrangian coordinates and the isentropic state equation, several evolution equations (one-dimensional, two-dimensional, three-dimensional and axisymmetric) are proposed and numerically solved in the time domain. No restriction on nonlinearity level is imposed. These developments allow the simulation of the time evolution of the pressure distribution inside the cavity, as well as the harmonics distribution. Distortion, nonlinear attenuation and rms pressure can be studied. Periodic (continue) and pulsed signal excitation are possible. Some results referred to complicated nonlinear waves are presented.
Vistas in applied mathematics: Numerical analysis, atmospheric sciences, immunology
Balakrishnan, A.V.; Dorodnitsyn, A.A.; Lions, J.L.
1986-01-01
Advances in the theory and application of numerical modeling techniques are discussed in papers contributed, primarily by Soviet scientists, on the occasion of the 60th birthday of Gurii I. Marchuk. Topics examined include splitting techniques for computations of industrial flows, the mathematical foundations of the k-epsilon turbulence model, splitting methods for the solution of the incompressible Navier-Stokes equations, the approximation of inhomogeneous hyperbolic boundary-value problems, multigrid methods, and the finite-element approximation of minimal surfaces. Consideration is given to dynamic modeling of moist atmospheres, satellite observations of the earth radiation budget and the problem of energy-active ocean regions, a numerical model of the biosphere for use with GCMs, and large-scale modeling of ocean circulation. Also included are several papers on modeling problems in immunology.
Numerical analysis of microholes film/effusion cooling effectiveness
NASA Astrophysics Data System (ADS)
Ochrymiuk, Tomasz
2017-10-01
Numerical simulations were performed to predict the film cooling effectiveness on the fiat plate with a three-dimensional discrete hole film cooling RSM-AKN turbulent heat transfer models based on variable turbulent Prandtl number approaches were considered. Obtained numerical results were directly compared with the data that came from an experiment based on Transient Liquid Crystal methodology. All implemented models for turbulent heat transfer performed sufficiently well for the considered case. It was confirmed, however, that the two-equation closure can give a detailed look into film cooling problems without using any time-consuming and inherently unsteady models. The RSM-AKN turbulent model was used in micoholes case too. The main target of simulations was maintain the same level of cooling efficiency ratio in both cases and confirm that is possible significantly reduce mass flows of the coolant in microholes case.
Numerical analysis of quench in coated conductors with defects
NASA Astrophysics Data System (ADS)
Liu, Wenbin; Yong, Huadong; Zhou, Youhe
2016-09-01
When the superconductor is subjected to local thermal perturbations, a large amount of joule heat may be generated in the conductor, which may lead to a quench. In a quench event, a normal zone irreversibly spreads throughout the conductor leading to failure of the superconducting device. In this paper, we will discuss the one-dimensional quench behavior in the coated conductors with internal defects or interface defects. Based on the numerical procedure given in the previous works, the normal zone propagation is studied by using the finite difference method. The numerical results are presented to discuss the normal zone propagation. We consider the effect of internal defect on the nonuniform temperature propagation. For the conductor with interface defects, it can be found that the normal zone propagation velocity is increased by defects.
A general numerical analysis of time-domain NQR experiments.
Harel, Elad; Cho, Herman
2006-12-01
We introduce a general numerical approach for solving the Liouville equation of an isolated quadrupolar nuclide that can be used to analyze the unitary dynamics of time-domain NQR experiments. A numerical treatment is necessitated by the dimensionality of the Liouville space, which precludes analytical, closed form solutions for I > 3/2. Accurate simulations of experimental nutation curves, forbidden transition intensities, powder and single crystal spectra, and off-resonance irradiation dynamics can be computed with this method. We also examine the validity of perturbative approximations where the signal intensity of a transition is proportional to the transition moment between the eigenstates of the system, thus providing a simple basis for determining selection rules. Our method allows us to calculate spectra for all values of the asymmetry parameter, eta, and sample orientations relative to the coil axis. We conclude by demonstrating the methodology for calculating the response of the quadrupole system to amplitude- and frequency-modulated pulses.
Fourier analysis of numerical algorithms for the Maxwell equations
NASA Technical Reports Server (NTRS)
Liu, Yen
1993-01-01
The Fourier method is used to analyze the dispersive, dissipative, and isotropy errors of various spatial and time discretizations applied to the Maxwell equations on multi-dimensional grids. Both Cartesian grids and non-Cartesian grids based on hexagons and tetradecahedra are studied and compared. The numerical errors are quantitatively determined in terms of phase speed, wave number, propagation direction, gridspacings, and CFL number. The study shows that centered schemes are more efficient than upwind schemes. The non-Cartesian grids yield superior isotropy and higher accuracy than the Cartesian ones. For the centered schemes, the staggered grids produce less errors than the unstaggered ones. A new unstaggered scheme which has all the best properties is introduced. The study also demonstrates that a proper choice of time discretization can reduce the overall numerical errors due to the spatial discretization.
Numerical analysis of a microwave torch with axial gas injection
Gritsinin, S. I.; Davydov, A. M.; Kossyi, I. A.; Kulumbaev, E. B.; Lelevkin, V. M.
2013-07-15
The characteristics of a microwave discharge in an argon jet injected axially into a coaxial channel with a shortened inner electrode are numerically analyzed using a self-consistent equilibrium gas-dynamic model. The specific features of the excitation and maintenance of the microwave discharge are determined, and the dependences of the discharge characteristics on the supplied electromagnetic power and gas flow rate are obtained. The calculated results are compared with experimental data.
Numerical analysis of laser paint removal from various substrates
NASA Astrophysics Data System (ADS)
Savastru, Dan; Savastru, Roxana; Lancranjan, Ion; Miclos, Sorin; Opran, Constantin
2013-06-01
Numerical simulation results obtained in investigating laser paint removal from different metal substrates, mainly aluminum and aluminum alloys, are presented. The main purpose of the developed simulation model is to define the laser installation specifications required for an operation that does not affect the substrate on which the paint is deposited. This is an important laser application in aeronautical industry. The developed simulation model considers transverse laser beam intensity distribution and, consequently, the temperature distribution in the processed mechanical component.
Application of Integrated Flood Analysis System (IFAS) for Dungun River Basin
NASA Astrophysics Data System (ADS)
Hafiz, I.; Nor, N. D. M.; Sidek, L. M.; Basri, H.; K, F.; Hanapi, M. N.; L, Livia
2013-06-01
The Northeast monsoon happening during the months of October until January is the major rainy season found in the eastern part of Peninsular Malaysia. The Dungun river basin (1,858 km2) is exposed to this season thus experiencing characteristically regular flooding due to the prolong rainfall events. The annual rainfall over the river basins are 2,880 mm with great proportion falling in the months of December (19.4%). This study is to apply the Integrated Flood Analysis System (IFAS) model which Dungun river basin has been chosen for this study as the catchments have range of flood and relevant data that can be used to develop the model. The satellite data used in this study is provided by JAXA Global Rainfall Watch. The main feature of this real-time flood analysis model is the satellite-based rainfall data input employed during the model creation phase. The performance of the model for the river basins from satellite and ground-based rainfall data are compared using three error analysis methods.
Numerical and semiclassical analysis of some generalized Casimir pistons
Schaden, M.
2009-05-15
The Casimir force due to a scalar field in a cylinder of radius r with a spherical cap of radius R>r is computed numerically in the world-line approach. A geometrical subtraction scheme gives the finite interaction energy that determines the Casimir force. The spectral function of convex domains is obtained from a probability measure on convex surfaces that is induced by the Wiener measure on Brownian bridges the convex surfaces are the hulls of. Due to reflection positivity, the vacuum force on the piston by a scalar field satisfying Dirichlet boundary conditions is attractive in these geometries, but the strength and short-distance behavior of the force depend strongly on the shape of the piston casing. For a cylindrical casing with a hemispherical head, the force on the piston does not depend on the dimension of the casing at small piston elevation a<
FEM numerical model analysis of magnetic nanoparticle tumor heating experiments.
Pearce, John A; Petyk, Alicia A; Hoopes, P Jack
2014-01-01
Iron oxide nanoparticles are currently under investigation as heating agents for hyperthermic treatment of tumors. Major determinants of effective heating include the biodistribution of magnetic materials, the minimum iron oxide loading required to achieve adequate heating, and practically achievable magnetic field strengths. These are inter-related criteria that ultimately determine the practicability of this approach to tumor treatment. Currently, we lack fundamental engineering design criteria that can be used in treatment planning and assessment. Coupling numerical models to experimental studies illuminate the underlying physical processes and can separate physical processes to determine their relative importance. Further, adding thermal damage and cell death process to the models provides valuable perspective on the likelihood of successful treatment. FEM numerical models were applied to increase the understanding of a carefully calibrated series of experiments in mouse mammary carcinoma. The numerical models results indicate that tumor loadings equivalent to approximately 1 mg of Fe3O4 per gram of tumor tissue are required to achieve adequate heating in magnetic field strengths of 34 kA/m (rms) at 160 kHz. Further, the models indicate that direct intratumoral injection of the nanoparticles results in between 1 and 20% uptake in the tissues.
Numerical and experimental analysis of particle dispersion in dust explosions
NASA Astrophysics Data System (ADS)
Christiansen, Mari G.; Berg, Ann Elin; Balakin, Boris V.; Kosinski, Pawel
2017-07-01
Dust explosions take place when small particles of flammable material such as grain, wood, plastic, coal and metal are dispersed in air and ignited. An important research tool that is used for describing dust explosion characteristics is the Hartmann apparatus, where dust is dispersed by a pressure wave. This makes it possible to find e.g. the minimum ignition energy. Nevertheless, there is a question whether the formed dust cloud is uniformly dispersed and how the solid particles behave as they flow. In addition to the scientific curiosity there is also a practical application, namely at what point in time the explosive mixture should be ignited in order to obtain the most representative results. The objective of this research was to run computational fluid dynamic (CFD) simulations, using the commercial software Star CCM+, with the purpose to numerically investigate the dispersion of a single particle in a modified Hartmann tube. Numerical models affecting the particle-wall and the particle-gas interactions were analysed, and the motion of the particle resolved numerically was verified with experimental results obtained using the Positron Emmision Particle Tracking (PEPT) technique.
Numerical Analysis of Electromagnetic Fields in Multiscale Model
NASA Astrophysics Data System (ADS)
Ma, Ji; Fang, Guang-You; Ji, Yi-Cai
2015-04-01
Modeling technique for electromagnetic fields excited by antennas is an important topic in computational electromagnetics, which is concerned with the numerical solution of Maxwell's equations. In this paper, a novel hybrid technique that combines method of moments (MoM) with finite-difference time-domain (FDTD) method is presented to handle the problem. This approach employed Huygen's principle to realize the hybridization of the two classical numerical algorithms. For wideband electromagnetic data, the interpolation scheme is used in the MoM based on the dyadic Green's function. On the other hand, with the help of equivalence principle, the scattered electric and magnetic fields on the Huygen's surface calculated by MoM are taken as the sources for FDTD. Therefore, the electromagnetic fields in the environment can be obtained by employing finite-difference time-domain method. Finally, numerical results show the validity of the proposed technique by analyzing two canonical samples. Supported in part by China Postdoctoral Science Foundation under Grant No. 201M550839, and in part by the Key Research Program of the Chinese Academy of Sciences under Grant No. KGZD-EW-603
Numerical analysis of biosonar beamforming mechanisms and strategies in bats.
Müller, Rolf
2010-09-01
Beamforming is critical to the function of most sonar systems. The conspicuous noseleaf and pinna shapes in bats suggest that beamforming mechanisms based on diffraction of the outgoing and incoming ultrasonic waves play a major role in bat biosonar. Numerical methods can be used to investigate the relationships between baffle geometry, acoustic mechanisms, and resulting beampatterns. Key advantages of numerical approaches are: efficient, high-resolution estimation of beampatterns, spatially dense predictions of near-field amplitudes, and the malleability of the underlying shape representations. A numerical approach that combines near-field predictions based on a finite-element formulation for harmonic solutions to the Helmholtz equation with a free-field projection based on the Kirchhoff integral to obtain estimates of the far-field beampattern is reviewed. This method has been used to predict physical beamforming mechanisms such as frequency-dependent beamforming with half-open resonance cavities in the noseleaf of horseshoe bats and beam narrowing through extension of the pinna aperture with skin folds in false vampire bats. The fine structure of biosonar beampatterns is discussed for the case of the Chinese noctule and methods for assessing the spatial information conveyed by beampatterns are demonstrated for the brown long-eared bat.
Numerical Analysis Of The Resistance To Pullout Test Of Clinched Assemblies Of Thin Metal Sheets
Jomaa, Moez; Billardon, Rene
2007-04-07
This paper presents the finite element analysis of the resistance of a clinch point to pullout test -that follows the numerical analysis of the forming process of the point-. The simulations have been validated by comparison with experimental evidences. The influence on the numerical predictions of various computation and process parameters have been evaluated.
Lower Permian Dry Mountain trough, eastern Nevada: preliminary basin analysis
Schwarz, D.L.; Snyder, W.S.; Spinosa, C.
1987-08-01
The Lower Permian Dry Mountain trough (DMT) is one of several basins that developed during the Late Pennsylvanian to Permian along the western edge of the North American continent. A tectonic mechanism has been suggested for the subsidence of the DMT, possibly due to reactivation of the Antler orogenic belt during the waning stages of Ancestral Rocky Mountain deformation. The DMT records marked subsidence with the appearance during the Artinskian (latest Wolfcampian) of a deeper water facies that consists of thin-bedded silty micrites and micritic mudstones rich in radiolarians and sponge spicules, characterized by a relative abundance of ammonoids, and rarer conodonts and Nereites ichnofacies trace fossils. Taxa recovered from a distinctive concretionary horizon at various locations provide an Artinskian datum on which to palinspastically reconstruct the DMT paleogeography. These taxa include ammonoids: Uraloceras, Medlicottia, Marathonites, Crimites, Metalegoceras, properrinitids; and conodonts: Neogondolella bisselli, Sweetognathus whitei, S. behnkeni, and Diplognathodus stevensi. The western margin facies of the DMT consists of Permian Carbon Ridge/Garden Valley Formations. Here, lowermost black Artinskianage euxinic micrites, considered a potential source rock for petroleum generation, are overlain by base-of-slope carbonate apron deposits, which, in turn, are overlain by base-of-slope carbonate apron deposits, which, in turn, are overlain by a thick, eastwardly prograding conglomerate wedge. Seismic profiles across Diamond Valley indicate a 3.0-4.6-km thick Tertiary sequence above the Paleozoic strata.
Numerical analysis of a rapid magnetic microfluidic mixer.
Wen, Chih-Yung; Liang, Kuok-Pong; Chen, Hua; Fu, Lung-Ming
2011-11-01
This paper presents a detailed numerical investigation of the novel active microfluidic mixer proposed by Wen et al. (Electrophoresis 2009, 30, 4179-4186). This mixer uses an electromagnet driven by DC or AC power to induce transient interactive flows between a water-based ferrofluid and DI water. Experimental results clearly demonstrate the mixing mechanism. In the presence of the electromagnet's magnetic field, the magnetic nanoparticles create a body force vector that acts on the mixed fluid. Numerical simulations show that this magnetic body force causes the ferrofluid to expand significantly and uniformly toward miscible water. The magnetic force also produces many extremely fine finger structures along the direction of local magnetic field lines at the interface in both upstream and downstream regions of the microchannel when the external steady magnetic strength (DC power actuation) exceeds 30 Oe (critical magnetic Peclet number Pe(m),cr = 2870). This study is the first to analyze these pronounced finger patterns numerically, and the results are in good agreement with the experimental visualization of Wen et al. (Electrophoresis 2009, 30, 4179-4186). The large interfacial area that accompanies these fine finger structures and the dominant diffusion effects occurring around the circumferential regions of fingers significantly enhance the mixing performance. The mixing ratio can be as high as 95% within 2.0 s. at a distance of 3.0 mm from the mixing channel inlet when the applied peak magnetic field supplied by the DC power source exceeds 60 Oe. This study also presents a sample implementation of AC power actuation in a numerical simulation, an experimental benchmark, and a simulation of DC power actuation with the same peak magnetic strength. The simulated flow structures of the AC power actuation agree well with the experimental visualization, and are similar to those produced by DC power. The AC and DC power actuated flow fields exhibited no
Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby
2006-05-26
The principal research effort for Phase 1 (Concept Development) of the project has been data compilation; determination of the tectonic, depositional, burial, and thermal maturation histories of the North Louisiana Salt Basin; basin modeling (geohistory, thermal maturation, hydrocarbon expulsion); petroleum system identification; comparative basin evaluation; and resource assessment. Existing information on the North Louisiana Salt Basin has been evaluated, an electronic database has been developed, and regional cross sections have been prepared. Structure, isopach and formation lithology maps have been constructed, and burial history, thermal maturation history, and hydrocarbon expulsion profiles have been prepared. Seismic data, cross sections, subsurface maps and burial history, thermal maturation history, and hydrocarbon expulsion profiles have been used in evaluating the tectonic, depositional, burial and thermal maturation histories of the basin. Oil and gas reservoirs have been found to be associated with salt-supported anticlinal and domal features (salt pillows, turtle structures and piercement domes); with normal faulting associated with the northern basin margin and listric down-to-the-basin faults (state-line fault complex) and faulted salt features; and with combination structural and stratigraphic features (Sabine and Monroe Uplifts) and monoclinal features with lithologic variations. Petroleum reservoirs include Upper Jurassic and Cretaceous fluvial-deltaic sandstone facies; shoreline, marine bar and shallow shelf sandstone facies; and carbonate shoal, shelf and reef facies. Cretaceous unconformities significantly contribute to the hydrocarbon trapping mechanism capacity in the North Louisiana Salt Basin. The chief petroleum source rock in this basin is Upper Jurassic Smackover lime mudstone beds. The generation of hydrocarbons from Smackover lime mudstone was initiated during the Early Cretaceous and continued into the Tertiary. Hydrocarbon
Simulation analysis of the ground-water flow system in the Portland Basin, Oregon and Washington
Morgan, David S.; McFarland, William D.
1996-01-01
This report presents results derived from a numerical model of the ground-water flow system in the Portland Basin, Oregon and Washington, that was used to test and refine the conceptual understanding of the flow system, estimate the effects of past and future human-caused changes to ground-water recharge and discharge on ground-water levels and streamflow, and determine priorities for ground-water monitoring and data collection that would facilitate improvements in the utility and accuracy of the model.
NASA Astrophysics Data System (ADS)
Mikhailov, V. O.; Parsons, T.; Simpson, R. W.; Timoshkina, E. P.; Williams, C.
2007-01-01
Data on present-day heat flow, subsidence history, and paleotemperature for the Sacramento Delta region, California, have been employed to constrain a numerical model of tectonic subsidence and thermal evolution of forearc basins. The model assumes an oceanic basement with an initial thermal profile dependent on its age subjected to refrigeration caused by a subducting slab. Subsidence in the Sacramento Delta region appears to be close to that expected for a forearc basin underlain by normal oceanic lithosphere of age 150 Ma, demonstrating that effects from both the initial thermal profile and the subduction process are necessary and sufficient. Subsidence at the eastern and northern borders of the Sacramento Valley is considerably less, approximating subsidence expected from the dynamics of the subduction zone alone. These results, together with other geophysical data, show that Sacramento Delta lithosphere, being thinner and having undergone deeper subsidence, must differ from lithosphere of the transitional type under other parts of the Sacramento Valley. Thermal modeling allows evaluation of the rheological properties of the lithosphere. Strength diagrams based on our thermal model show that, even under relatively slow deformation (10-17 s-1), the upper part of the delta crystalline crust (down to 20-22 km) can fail in brittle fashion, which is in agreement with deeper earthquake occurrence. Hypocentral depths of earthquakes under the Sacramento Delta region extend to nearly 20 km, whereas, in the Coast Ranges to the west, depths are typically less than 12-15 km. The greater width of the seismogenic zone in this area raises the possibility that, for fault segments of comparable length, earthquakes of somewhat greater magnitude might occur than in the Coast Ranges to the west.
Mikhailov, V.O.; Parsons, T.; Simpson, R.W.; Timoshkina, E.P.; Williams, C.
2007-01-01
Data on present-day heat flow, subsidence history, and paleotemperature for the Sacramento Delta region, California, have been employed to constrain a numerical model of tectonic subsidence and thermal evolution of forearc basins. The model assumes an oceanic basement with an initial thermal profile dependent on its age subjected to refrigeration caused by a subducting slab. Subsidence in the Sacramento Delta region appears to be close to that expected for a forearc basin underlain by normal oceanic lithosphere of age 150 Ma, demonstrating that effects from both the initial thermal profile and the subduction process are necessary and sufficient. Subsidence at the eastern and northern borders of the Sacramento Valley is considerably less, approximating subsidence expected from the dynamics of the subduction zone alone. These results, together with other geophysical data, show that Sacramento Delta lithosphere, being thinner and having undergone deeper subsidence, must differ from lithosphere of the transitional type under other parts of the Sacramento Valley. Thermal modeling allows evaluation of the rheological properties of the lithosphere. Strength diagrams based on our thermal model show that, even under relatively slow deformation (10−17 s−1), the upper part of the delta crystalline crust (down to 20–22 km) can fail in brittle fashion, which is in agreement with deeper earthquake occurrence. Hypocentral depths of earthquakes under the Sacramento Delta region extend to nearly 20 km, whereas, in the Coast Ranges to the west, depths are typically less than 12–15 km. The greater width of the seismogenic zone in this area raises the possibility that, for fault segments of comparable length, earthquakes of somewhat greater magnitude might occur than in the Coast Ranges to the west.
NASA Astrophysics Data System (ADS)
Lee, Sang-Mook; Kim, Yoon-Mi
2016-04-01
Marginal basins locate between the continent and arc islands often exhibit diverse style of opening, from regions that appear to have formed by well-defined and localized spreading center (manifested by the presence of distinct seafloor magnetic anomaly patterns) to those with less obvious zones of extension and a broad magmatic emplacement most likely in the lower crust. Such difference in the style of back-arc basin formation may lead to marked difference in crustal structure in terms of its overall thickness and spatial variations. The Ulleung Basin, one of three major basins in the East Sea/Sea of Japan, is considered to represent a continental rifting end-member of back-arc opening. Although a great deal of work has been conducted on the sedimentary sections in the last several decades, the deep crustal sections have not been systematically investigated for long time, and thus the structure and characteristics of the crust remain poorly understood. This study examines the marine gravity anomalies of the Ulleung Basin in order to understand the crustal structure using crucial sediment-thickness information. Our analysis shows that the Moho depth in general varies from 16 km at the basin center to 22 km at the margins. However, within the basin center, the inferred thickness of the crust is more or less the same (10-12 km), thus by varying only about 10-20% of the total thickness, contrary to the previous impression. The almost-uniformly-thick crust that is thicker than a normal oceanic crust (~ 7 km) is consistent with previous observations using ocean bottom seismometers and recent deep seismic results from the nearby Yamato Basin. Another important finding is that small residual mantle gravity anomaly highs exist in the northern part of the basin. These highs are aligned in the NNE-SSW direction which correspond to the orientation of the major tectonic structures on the Korean Peninsula, raising the possibility that, though by a small degree, they are a
Numerical analysis of core catcher efficiency for VVER-1200
Zvonarev, Yu. A.; Tsurikov, D. F.; Kobzar, V. L.; Volchek, A. M.; Kiselev, N. P.; Strizhov, V. F.; Filippov, A. S.; Moiseenko, E. V.
2011-12-15
A brief description of the HEFEST-ULR code and numerical results for corium behavior in a core catcher for the VVER-1200 (NPP-2006 project) are presented. Physical, chemical, and thermal processes during corium pool formation and cooling in the core catcher are examined for the case of severe accidents in NPP-2006 with the VVER-1200. Basic corium parameters, including its composition, structure, temperature evolution, density, and aggregative state, are determined. The minimum margin for critical heat flux at the external surface of the core catcher is estimated.
Numerical analysis of the symmetric hybrid transducer ultrasonic motor.
Satonobu, J; Friend, J R; Nakamura, K; Ueha, S
2001-11-01
In this paper, operation of a symmetric hybrid transducer ultrasonic motor with output produced by two rotors connected together via a driveshaft is numerically analyzed and compared with the traditional asymmetric hybrid transducer motor design that produces its output from only one rotor. A one-dimensional finite element model for torsional vibration in the stator and a Coulomb friction model for rotor/stator contact associated with the longitudinal vibration of the motor are introduced. The calculation results demonstrate that the symmetric design is capable of performance comparable with the traditional asymmetric design when an optimum static spring force in the rotor/stator contact interface is applied during operation.
Numerical Method and Analysis of Consistency for Electrodiffusion Problem
NASA Astrophysics Data System (ADS)
Filipek, R.; Szyszkiewicz, K.; Danielewski, M.; Lewenstam, A.
2007-12-01
Numerical procedure based on method of lines for time-dependent electrodiffusion transport is developed. Finite difference space discretization with suitably selected weights based on a non-uniform grid is applied. Consistency of this method and the method put forward by Brumleve and Buck are analyzed and compared. The resulting stiff system of ODEs is effectively solved using the Radau IIa integrator. The applications to selected electrochemical systems: liquid junction, bi-ionic case and fused salts have been tested. Results for ion-selective electrodes are demonstrated.
Preliminary numerical analysis of improved gas chromatograph model
NASA Technical Reports Server (NTRS)
Woodrow, P. T.
1973-01-01
A mathematical model for the gas chromatograph was developed which incorporates the heretofore neglected transport mechanisms of intraparticle diffusion and rates of adsorption. Because a closed-form analytical solution to the model does not appear realizable, techniques for the numerical solution of the model equations are being investigated. Criteria were developed for using a finite terminal boundary condition in place of an infinite boundary condition used in analytical solution techniques. The class of weighted residual methods known as orthogonal collocation is presently being investigated and appears promising.
NASA Astrophysics Data System (ADS)
Dwelle, M. C.; Ivanov, V. Y.; Berrocal, V.
2014-12-01
Forecasting rainfall in areas with sparse monitoring efforts is critical to making inferences about the health of ecosystems and built environments. Recent advances in scientific computing have allowed forecasting and climate models to increase their spatial and temporal resolution. Combined with observed point precipitation from monitoring stations, these models can be used to inform dynamic spatial statistical models for precipitation using methods from geostatistics and machine learning. To prove the feasibility, process, and capabilities of these statistical models, we present a case study of two statistical models of precipitation for the Amazon River basin from 2003-2010 that can infer a spatial process at a point using areal data from numerical model output. We investigate the seasonality and accumulation of rainfall, and the occurrence of no-rainfall and large-rainfall events. These parameters are used since they provide valuable information on possible model biases when using climate models for forecasts of the future process of precipitation in the Amazon basin. This information can be vital for ecosystem, agriculture, and water-resource management. We use observed precipitation data from weather stations, three areal datasets derived from observed precipitation (CFSR, CMORPH-CRT, GPCC) and three climate model precipitation datasets from CMIP5 (MIROC4h, HadGEM2-CC, and GISS-E2H) to construct the models. The observational data in the model domain is sparse, with 195 stations in the approximate 7×106 square kilometers of the Amazon basin, and therefore requires the areal data to create a more robust model. The first model uses the method of Bayesian melding to combine and make inferences from the included data sets, and the second uses a regression model with spatially and temporally-varying coefficients. The models of precipitation are fitted using the areal products and a subset of the point data, while another subset of point data is held out for
Ernest A. Mancini; Donald A. Goddard; Ronald K. Zimmerman
2005-05-10
The principal research effort for Year 2 of the project has been data compilation and the determination of the burial and thermal maturation histories of the North Louisiana Salt Basin and basin modeling and petroleum system identification. In the first nine (9) months of Year 2, the research focus was on the determination of the burial and thermal maturation histories, and during the remainder of the year the emphasis has basin modeling and petroleum system identification. Existing information on the North Louisiana Salt Basin has been evaluated, an electronic database has been developed, regional cross sections have been prepared, structure and isopach maps have been constructed, and burial history, thermal maturation history and hydrocarbon expulsion profiles have been prepared. Seismic data, cross sections, subsurface maps and related profiles have been used in evaluating the tectonic, depositional, burial and thermal maturation histories of the basin. Oil and gas reservoirs have been found to be associated with salt-supported anticlinal and domal features (salt pillows, turtle structures and piercement domes); with normal faulting associated with the northern basin margin and listric down-to-the-basin faults (state-line fault complex) and faulted salt features; and with combination structural and stratigraphic features (Sabine and Monroe Uplifts) and monoclinal features with lithologic variations. Petroleum reservoirs are mainly Upper Jurassic and Lower Cretaceous fluvial-deltaic sandstone facies and Lower Cretaceous and Upper Cretaceous shoreline, marine bar and shallow shelf sandstone facies. Cretaceous unconformities significantly contribute to the hydrocarbon trapping mechanism capacity in the North Louisiana Salt Basin. The chief petroleum source rock in this basin is Upper Jurassic Smackover lime mudstone beds. The generation of hydrocarbons from Smackover lime mudstone was initiated during the Early Cretaceous and continued into the Tertiary
Process-based distributed modeling approach for analysis of sediment dynamics in a river basin
NASA Astrophysics Data System (ADS)
Kabir, M. A.; Dutta, D.; Hironaka, S.
2011-04-01
Modeling of sediment dynamics for developing best management practices of reducing soil erosion and of sediment control has become essential for sustainable management of watersheds. Precise estimation of sediment dynamics is very important since soils are a major component of enormous environmental processes and sediment transport controls lake and river pollution extensively. Different hydrological processes govern sediment dynamics in a river basin, which are highly variable in spatial and temporal scales. This paper presents a process-based distributed modeling approach for analysis of sediment dynamics at river basin scale by integrating sediment processes (soil erosion, sediment transport and deposition) with an existing process-based distributed hydrological model. In this modeling approach, the watershed is divided into an array of homogeneous grids to capture the catchment spatial heterogeneity. Hillslope and river sediment dynamic processes have been modeled separately and linked to each other consistently. Water flow and sediment transport at different land grids and river nodes are modeled using one dimensional kinematic wave approximation of Saint-Venant equations. The mechanics of sediment dynamics are integrated into the model using representative physical equations after a comprehensive review. The model has been tested on river basins in two different hydro climatic areas, the Abukuma River Basin, Japan and Latrobe River Basin, Australia. Sediment transport and deposition are modeled using Govers transport capacity equation. All spatial datasets, such as, Digital Elevation Model (DEM), land use and soil classification data, etc., have been prepared using raster "Geographic Information System (GIS)" tools. The results of relevant statistical checks (Nash-Sutcliffe efficiency and R-squared value) indicate that the model simulates basin hydrology and its associated sediment dynamics reasonably well. This paper presents the model including descriptions
Process-based distributed modeling approach for analysis of sediment dynamics in a river basin
NASA Astrophysics Data System (ADS)
Kabir, M. A.; Dutta, D.; Hironaka, S.
2010-08-01
Modeling of sediment dynamics for developing best management practices of reducing soil erosion and of sediment control has become essential for sustainable management of watersheds. Precise estimation of sediment dynamics is very important since soils are a major component of enormous environmental processes and sediment transport controls lake and river pollution extensively. Different hydrological processes govern sediment dynamics in a river basin, which are highly variable in spatial and temporal scales. This paper presents a process-based distributed modeling approach for analysis of sediment dynamics at river basin scale by integrating sediment processes (soil erosion, sediment transport and deposition) with an existing process-based distributed hydrological model. In this modeling approach, the watershed is divided into an array of homogeneous grids to capture the catchment spatial heterogeneity. Hillslope and river sediment dynamic processes have been modeled separately and linked to each other consistently. Water flow and sediment transport at different surface grids and river nodes are modeled using one-dimensional kinematic wave approximation of Saint-Venant equations. The mechanics of sediment dynamics are integrated into the model using representative physical equations after a comprehensive review. The model has been tested on river basins in two different hydro climatic areas, the Abukuma River Basin, Japan and Latrobe River Basin, Australia. Sediment transport and deposition are modeled using Govers transport capacity equation. All spatial datasets, such as, Digital Elevation Model (DEM), land use and soil classification data, etc., have been prepared using raster "Geographic Information System (GIS)" tools. The results of relevant statistical checks (Nash-Sutcliffe efficiency and R-squared value) indicate that the model simulates basin hydrology and its associated sediment dynamics reasonably well. This paper presents the model including
Analysis of temporal and spatial trends of hydro-climatic variables in the Wei River Basin.
Zhao, Jing; Huang, Qiang; Chang, Jianxia; Liu, Dengfeng; Huang, Shengzhi; Shi, Xiaoyu
2015-05-01
The Wei River is the largest tributary of the Yellow River in China. The relationship between runoff and precipitation in the Wei River Basin has been changed due to the changing climate and increasingly intensified human activities. In this paper, we determine abrupt changes in hydro-climatic variables and identify the main driving factors for the changes in the Wei River Basin. The nature of the changes is analysed based on data collected at twenty-one weather stations and five hydrological stations in the period of 1960-2010. The sequential Mann-Kendall test analysis is used to capture temporal trends and abrupt changes in the five sub-catchments of the Wei River Basin. A non-parametric trend test at the basin scale for annual data shows a decreasing trend of precipitation and runoff over the past fifty-one years. The temperature exhibits an increase trend in the entire period. The potential evaporation was calculated based on the Penman-Monteith equation, presenting an increasing trend of evaporation since 1990. The stations with a significant decreasing trend in annual runoff mainly are located in the west of the Wei River primarily interfered by human activities. Regression analysis indicates that human activity was possibly the main cause of the decline of runoff after 1970.
Ernest A. Mancini
2005-03-31
The principal research effort for Year 2 of the project is the determination of the burial and thermal maturation histories and basin modeling and petroleum system identification of the North Louisiana Salt Basin. In the first six (6) to nine (9) months of Year 2, the research focus is on the determination of the burial and thermal maturation histories and the remainder of the year the emphasis is on basin modeling and petroleum system identification. No major problems have been encountered to date, and the project is on schedule.
Ernest A. Mancini
2004-11-05
The principal research effort for Year 2 of the project is the determination of the burial and thermal maturation histories and basin modeling and petroleum system identification of the North Louisiana Salt Basin. In the first six (6) to nine (9) months of Year 2, the research focus is on the determination of the burial and thermal maturation histories and the remainder of the year the emphasis is on basin modeling and petroleum system identification. No major problems have been encountered to date, and the project is on schedule.
Numerical analysis and prediction of laser forming of thin plate
NASA Astrophysics Data System (ADS)
Tamsaout, Toufik; Amara, EL-Hachemi
2012-03-01
Laser forming is a technique consisting in the design and the construction of complex metallic work-pieces with special shapes, difficult to achieve with the conventional techniques. By using lasers, the main advantage of the process is that it is contactless and does not require any external force. It offers also more flexibility for a lower price. This kind of processing interests the industries that use the stamping or other costly ways for prototypes such as in the aero-spatial, automotive, naval and microelectronics industries. The analytical modeling of laser forming process is often complex or impossible to achieve, since the dimensions and the mechanical properties change with the time and in the space. Therefore, the numerical approach is more suitable for laser forming modeling. Our numerical study is divided into two models, the first one is a purely thermal treatment which allows the determination of the temperature field produced by a laser pass, and the second one consists in the thermomechanical coupling treatment. The temperature field resulting from the first stage is used to calculate the stress field, the deformations and the bending angle of the plate. The thermo-mechanical properties of material are isotropic, but temperature-dependant.
Numerical analysis of the spatial range of the Kondo effect
Busser, C. A.; Martins, G. B.; Ribeiro, L. Costa; Vernek, E.; Anda, E. V.; Dagotto, Elbio R
2010-01-01
The spatial length of the Kondo screening is still a controversial issue related to Kondo physics. While renormalization-group and Bethe-Ansatz solutions have provided detailed information about the thermodynamics of magnetic impurities, they are insufficient to study the effect on the surrounding electrons, i.e., the spatial range of the correlations created by the Kondo effect between the localized magnetic moment and the conduction electrons. The objective of this work is to present a quantitative way of measuring the extension of these correlations by studying their effect directly on the local density of states (LDOS) at arbitrary distances from the impurity. The numerical techniques used, the embedded cluster approximation, the finite-U slave bosons, and numerical renormalization group, calculate the Green s functions in real space. With this information, one can calculate how the local density of states away from the impurity is modified by its presence, below and above the Kondo temperature, and then estimate the range of the disturbances in the noninteracting Fermi sea due to the Kondo effect, and how it changes with the Kondo temperature TK. The results obtained agree with results obtained through spin-spin correlations, showing that the LDOS captures the phenomenology of the Kondo cloud as well.
Numerical Analysis of Transient Temperature Response of Soap Film
NASA Astrophysics Data System (ADS)
Tanaka, Seiichi; Tatesaku, Akihiro; Dantsuka, Yuki; Fujiwara, Seiji; Kunimine, Kanji
2015-11-01
Measurements of thermophysical properties of thin liquid films are important to understand interfacial phenomena due to film structures composed of amphiphilic molecules in soap film, phospholipid bilayer of biological cell and emulsion. A transient hot-wire technique for liquid films less than 1 \\upmu m thick such as soap film has been proposed to measure the thermal conductivity and diffusivity simultaneously. Two-dimensional heat conduction equations for a solid cylinder with a liquid film have been solved numerically. The temperature of a thin wire with liquid film increases steeply with its own heat generation. The feasibility of this technique is verified through numerical experiments for various thermal conductivities, diffusivities, and film thicknesses. Calculated results indicate that the increase in the volumetric average temperature of the thin wire sufficiently varies with the change of thermal conductivity and diffusivity of the soap film. Therefore, the temperature characteristics could be utilized to evaluate both the thermal conductivity and diffusivity using the Gauss-Newton method.
Numerical solution-space analysis of satisfiability problems
NASA Astrophysics Data System (ADS)
Mann, Alexander; Hartmann, A. K.
2010-11-01
The solution-space structure of the three-satisfiability problem (3-SAT) is studied as a function of the control parameter α (ratio of the number of clauses to the number of variables) using numerical simulations. For this purpose one has to sample the solution space with uniform weight. It is shown here that standard stochastic local-search (SLS) algorithms like average satisfiability (ASAT) exhibit a sampling bias, as does “Metropolis-coupled Markov chain Monte Carlo” (MCMCMC) (also known as “parallel tempering”) when run for feasible times. Nevertheless, unbiased samples of solutions can be obtained using the “ballistic-networking approach,” which is introduced here. It is a generalization of “ballistic search” methods and yields also a cluster structure of the solution space. As application, solutions of 3-SAT instances are generated using ASAT plus ballistic networking. The numerical results are compatible with a previous analytical prediction of a simple solution-space structure for small values of α and a transition to a clustered phase at αc≈3.86 , where the solution space breaks up into several non-negligible clusters. Furthermore, in the thermodynamic limit there are, even for α=4.25 close to the SAT-UNSAT transition αs≈4.267 , always clusters without any frozen variables. This may explain why some SLS algorithms are able to solve very large 3-SAT instances close to the SAT-UNSAT transition.
Numerical Analysis of Magnetic Effect on Human Breathing
NASA Astrophysics Data System (ADS)
Lee, Chang Ho; Lu, Shu-Shen; Tagawa, Toshio; Ozoe, Hiroyuki; Hyun, Jae Min
A numerical study is made of flow of air in human breathing. A permanent magnet is placed on the nose to create a magnetic field. The permanent magnet is modeled as a coil in which electric current flows, and the passage of air in the human body is modeled as a circular pipe. Airflow is induced by the applied pressure difference between the interior and exterior of the human body. An inhalation flow of constant pressure difference (model I) and a flow of pulsating pressure difference (model II) were examined for unsteady developments of flow, temperature and oxygen concentration, by numerical techniques. Transient responses are affected by both the temperature and oxygen concentrations. Flow of inhalation is enhanced under a magnetic field. High-temperature air, with a low oxygen-concentration, in the passage is repelled from the magnet toward the interior by the magnetizing force, and exhalation is suppressed by a similar mechanism. Suppression in the exhalation overwhelms enhancement in the inhalation, and this tendency is pronounced as the amplitude of pressure oscillation increases.
Numerical analysis of cell adhesion in capillary flow
NASA Astrophysics Data System (ADS)
Takeishi, Naoki; Imai, Yohsuke; Ishida, Shunichi; Omori, Toshihiro; Kamm, Roger; Ishikawa, Takuji
2016-11-01
Numerical simulation of cell adhesion was performed for capillaries whose diameter is comparable to or smaller than that of the cell. Despite a lot of works about leukocyte and tumor cell rolling, cell motion in capillaries has remained unclear. The solid and fluid mechanics of a cell in flow was coupled with a slip bond model of ligand-receptor interactions. When the size of a capillary was reduced, the cell always transitioned to "bullet-like" motion, with a consequent decrease in the velocity of the cell. A state diagram is obtained for various values of capillary diameter and receptor density. According to our numerical results, bullet motion enables firm adhesion of a cell to the capillary wall even for a weak ligand-receptor binding. We also quantified effects of various parameters, including the dissociation rate constant, the spring constant, and the reactive compliance on the characteristics of cell motion. Our results suggest that even under the interaction between PSGL-1 and P-selectin, which is mainly responsible for leukocyte rolling, a cell is able to show firm adhesion in a small capillary. These findings may help in understanding such phenomena as leukocyte plugging and cancer metastasis. This research was supported by JSPS KAKENHI Grant Numbers 25000008, 26107703, 14J03967. We also acknowledge support from the Tohoku University Division for International Advanced Research and Education Organization.
NASA Astrophysics Data System (ADS)
Gusev, Anatoly; Diansky, Nikolay; Zalesny, Vladimir
2010-05-01
The original program complex is proposed for the ocean circulation sigma-model, developed in the Institute of Numerical Mathematics (INM), Russian Academy of Sciences (RAS). The complex can be used in various curvilinear orthogonal coordinate systems. In addition to ocean circulation model, the complex contains a sea ice dynamics and thermodynamics model, as well as the original system of the atmospheric forcing implementation on the basis of both prescribed meteodata and atmospheric model results. This complex can be used as the oceanic block of Earth climate model as well as for solving the scientific and practical problems concerning the World ocean and its separate oceans and seas. The developed program complex can be effectively used on parallel shared memory computational systems and on contemporary personal computers. On the base of the complex proposed the ocean general circulation model (OGCM) was developed. The model is realized in the curvilinear orthogonal coordinate system obtained by the conformal transformation of the standard geographical grid that allowed us to locate the system singularities outside the integration domain. The horizontal resolution of the OGCM is 1 degree on longitude, 0.5 degree on latitude, and it has 40 non-uniform sigma-levels in depth. The model was integrated for 100 years starting from the Levitus January climatology using the realistic atmospheric annual cycle calculated on the base of CORE datasets. The experimental results showed us that the model adequately reproduces the basic characteristics of large-scale World Ocean dynamics, that is in good agreement with both observational data and results of the best climatic OGCMs. This OGCM is used as the oceanic component of the new version of climatic system model (CSM) developed in INM RAS. The latter is now ready for carrying out the new numerical experiments on climate and its change modelling according to IPCC (Intergovernmental Panel on Climate Change) scenarios in the
Notes on numerical reliability of several statistical analysis programs
Landwehr, J.M.; Tasker, Gary D.
1999-01-01
This report presents a benchmark analysis of several statistical analysis programs currently in use in the USGS. The benchmark consists of a comparison between the values provided by a statistical analysis program for variables in the reference data set ANASTY and their known or calculated theoretical values. The ANASTY data set is an amendment of the Wilkinson NASTY data set that has been used in the statistical literature to assess the reliability (computational correctness) of calculated analytical results.
Numerical analysis and experimental research of the rubber boot of the joint drive vehicle
NASA Astrophysics Data System (ADS)
Ziobro, Jan
2016-04-01
The article presents many numerical studies and experimental research of the drive rubber boot of the joint drive vehicle. Performance requirements have been discussed and the required coefficients of the mathematical model for numerical simulation have been determined. The behavior of living in MSC.MARC environment was examined. In the analysis the following have been used: hyperplastic two-parameter model of the Mooney-Rivlin material, large displacements procedure, safe contact condition, friction on the sides of the boots. 3D numerical model of the joint bootwas analyzed under influence of the forces: tensile, compressive, centrifugal and angular. Numerous results of studies have been presented. An appropriate test stand was built and comparison of the results of the numerical analysis and the results of experimental studies was made. Numerous requests and recommendations for utilitarian character have been presented.
Numerical analysis of kinematic soil—pile interaction
NASA Astrophysics Data System (ADS)
Castelli, Francesco; Maugeri, Michele; Mylonakis, George
2008-07-01
In the present study, the response of singles pile to kinematic seismic loading is investigated using the computer program SAP2000@. The objectives of the study are: (1) to develop a numerical model that can realistically simulate kinematic soil-structure interaction for piles accounting for discontinuity conditions at the pile-soil interface, energy dissipation and wave propagation; (2) to use the model for evaluating kinematic interaction effects on pile response as function of input ground motion; and (3) to present a case study in which theoretical predictions are compared with results obtained from other formulations. To evaluate the effects of kinematic loading, the responses of both the free-field soil (with no piles) and the pile were compared. Time history and static pushover analyses were conducted to estimate the displacement and kinematic pile bending under seismic loadings.
Numerical analysis of a two-dimensional nonsteady detonations
NASA Technical Reports Server (NTRS)
Taki, S.; Fujiwara, T.
1976-01-01
In the present work a system of two-dimensional nonsteady hydrodynamic and chemical kinetic equations was numerically integrated for an exothermic system. Assumed two-step reaction model simulates practically an oxyhydrogen mixture. The calculation starts from a plane Chapman-Jouguet detonation as an initial condition. Two-dimensional disturbances are generated by artificially placing nonuniformities ahead of the detonation front. Regardless of the difference of the given initial disturbances, a fixed number of triple shock waves were produced for a fixed combination of mixture model and geometry when the transition period was over. This shows that for a given detonation tube geometry any exothermic system has its own characteristic multidimensional structure. The obtained number of triple shock waves contained in the detonation front was in agreement with existing experimental observations under the same condition.
A Numerical Analysis of a Light Slowing and Storage
NASA Astrophysics Data System (ADS)
Chough, Young-Tak
2015-12-01
We provide an in-depth numerical study on creation of stationary light pulses (SLP) in a cold atomic medium, locating the optimal parameter space for experimental realization. We visualize the dynamics of the atoms and the field inside the medium. We find that as the coupling field strength increases, the light slowing effect is actually diminished. It also turns out that the spatial profile of the pulse inside the medium is indeed not symmetric around its apex, and we point out that this asymmetry causes the energy imbalance between the two signals retrieved into the opposite directions, in addition to such extrinsic reasons as the disparity between the coupling field strengths or the imperfect centering of the pulse in the medium at the time of "writing".
Mathematical analysis and numerical simulation of a model of morphogenesis.
Muñoz, Ana I; Tello, José Ignacio
2011-10-01
We consider a simple mathematical model of distribution of morphogens (signaling molecules responsible for the differentiation of cells and the creation of tissue patterns). The mathematical model is a particular case of the model proposed by Lander, Nie and Wan in 2006 and similar to the model presented in Lander, Nie, Vargas and Wan 2005. The model consists of a system of three equations: a PDE of parabolic type with dynamical boundary conditions modelling the distribution of free morphogens and two ODEs describing the evolution of bound and free receptors. Three biological processes are taken into account: diffusion, degradation and reversible binding. We study the stationary solutions and the evolution problem. Numerical simulations show the behavior of the solution depending on the values of the parameters.
On estimating gravity anomalies from gradiometer data. [by numerical analysis
NASA Technical Reports Server (NTRS)
Argentiero, P.; Garza-Robles, R.
1976-01-01
The Gravsat-gradiometer mission involves flying a gradiometer on a gravity satellite (Gravsat) which is in a low, polar, and circular orbit. Results are presented of a numerical simulation of the mission which demonstrates that, if the satellite is in a 250-km orbit, 3- and 5-degree gravity anomalies may be estimated with accuracies of 0.03 and 0.01 mm/square second (3 and 1 mgal), respectively. At an altitude of 350 km, the results are 0.07 and 0.025 mm.square second (7 and 2.5 mgal), respectively. These results assume a rotating type gradiometer with a 0.1 -etvos unit accuracy. The results can readily be scaled to reflect another accuracy level.
Numerical analysis of Coleman-de Luccia tunneling
NASA Astrophysics Data System (ADS)
Goto, Yuhei; Okuyama, Kazumi
2016-08-01
In this paper, we study the false vacuum decay of a single scalar field ϕ coupled to gravity described by the Coleman-de Luccia (CdL) instanton. We show that it is possible to numerically calculate the bounce factor, which is related to the CdL tunneling rate, without using the thin-wall approximation. In this paper, we consider 1/cosh(ϕ)- and cos(ϕ)-type potentials as examples, which have cosmological and phenomenological applications. Especially, in the cos(ϕ)-type potential, we show that the range of values in which axion decay constant can take is restricted by the form of the periodic potential if the CdL tunneling occurs.
Performance analysis of a mirror by numerical iterative method.
Park, Kwijong; Cho, Myung; Lee, Dae-Hee; Moon, Bongkon
2014-12-29
Zernike polynomials are generally used to predict the optical performance of a mirror. However, it can also be done by a numerical iterative method. As piston, tip, tilt, and defocus (P.T.T.F) aberrations can be easily removed by optical alignment, we iteratively used a rotation transformation and a paraboloid graph subtraction for removal of the aberrations from a raw deformation of the optical surface through a Finite Element Method (FEM). The results of a 30 cm concave circular mirror corrected by the iterative method were almost the same as those yielded by Zernike polynomial fitting, and the computational time was fast. In addition, a concave square mirror whose surface area is π was analyzed in order to visualize the deformation maps of a general mirror aperture shape. The iterative method can be applicable efficiently because it does not depend on the mirror aperture shape.
Magnetic induction of electroporation: numerical analysis and technical limitations.
David, Marcelo; Golberg, Roman; Rubinsky, Boris
2014-01-01
Electric fields delivered across biological cells can cause structural and functional changes to the cell membrane, such as electroporation. An important application of electroporation is in the permeabilization of skin cells. Currently these cells are electroporated with contact electrodes. In this study we explore the feasibility of using electromagnetic induction for non-contact electroporation of skin cells, and the effect of various design parameters on the process. We derived a simple analytical solution that lends itself to a systematic study of design parameters and verified the solution with a numeric solution of the Maxwell equations using finite elements. A short feasibility study of the system implementation is done, concluding that there are technological limitations that must be met in the future in order to build such a device.
Experimental and Numerical Analysis of Structural Acousticcontrol Interior Noise Reduction
NASA Technical Reports Server (NTRS)
Mei, Chuh; Bevan, Jeffrey S.
1999-01-01
The research results contained in this technical report were performed under the NASA grant entitled "Experimental and Numerical Structural Acoustic Control for Interior Noise Reduction". The report is based essentially on partial progress of the Ph.D. dissertation prepared by Jeffrey S. Bevan under direct guidance of Dr. Chuh Mei. The document presents a finite element formulation and control of sound radiated from cylindrical panels embedded with piezoceramic actuators. The extended MIN6 shallow shell element is fully electrical-structural coupled. A piezoelectric modal actuator participation (PMAP) is defined which indicates the actuator performance to each of the offending modes. Genetic algorithm is also employed to validate the sensor and actuator locations determined by the PMAP criteria. The work was conducted at the Department of Aerospace Engineering, Old Dominion University. Mr. Travis L. Turner, Structural Acoustics Branch, NASA Langley Research Center is the technical monitor.
Numerical analysis of MPD arcs for plasma acceleration
Park, W.T.; Choi, D.I.
1987-10-01
The characteristics of the arc region of the plasma thruster are investigated from the numerical solutions of coupled MHD equations. In this model the flow is assumed to be two-dimensional but all other realistic effects are included. They are the Hall effect, ion slip term, and other dissipations such as viscosity, thermal conductivity, and electrical resistivity. The results show that the current concentrates at the trailing edge of the anode and that the temperature of the area is raised. Also, the Hall current causes harmful effects by lowering the thrust efficiency and eroding the electrodes. The thermal diffusion is a beneficial effect in that it raises the thrust efficiency and prevents the erosion of the electrodes.
A General Numerical Analysis of Time-Domain NQR Experiments
Harel, Elad; Cho, Herman M.
2006-12-01
We introduce a general numerical approach for solving the Liouville equation of a quadrupolar nuclide that we show can be used to analyze time-domain NQR experiments. A computer-based treatment is necessitated by the dimensionality of the Liouville space, which precludes analytical, closed form solutions for I > 3/2. Accurate simulations of experimental nutation curves, forbidden transition intensities, powder and single crystal spectra, and off-resonance irradiation dynamics can be computed with this method. We also examine the validity of perturbative approximations where the signal intensity of a transition is proportional to the transition moment between the eigenstates of the system, thus providing a simple basis for determining selection rules. Our method allows us to calculate spectra for all values of the asymmetry parameter, ?, and sample orientations relative to the coil axis. We conclude by demonstrating the methodology for calculating the response of the quadrupole system to amplitude- and frequency-modulated pulses.
Numerical analysis of internal waves in stratified wake flows
NASA Astrophysics Data System (ADS)
Fraunie, Philppe
2014-05-01
In laboratory investigations, increased attention has been given to internal waves generated by stationary placed oscillating sources and moving bodies in stratified fluids [1]. The main attention was paid to study flows past bodies of perfect shapes like sphere [2], cylinder [3] of thin strip [3] which are the best theoretical (analytical or numerical) studies. Due to simplicity of geometry, flow around a strip has a potential to investigate separately effects of a drag and lift forces on the body by changing the slope of the horizontally moving strip which can be placed vertically [1], horizontally [2], or be tilted under some angle to the direction of towing velocity [5]. Numeric modeling of a flow past vertical strip uniformly towing with permanent velocity in horizontal direction in a linearly stratified talk which was based on a finite differences solver adapted to the low Reynolds Navier-Stokes equation with transport equation for salinity (LES simulation [6] and RANS [7]) has demonstrated reasonable agreement with data of Schlieren visualization, density marker and probe measurements of internal wave fields. The chosen test cases allowed demonstrating the ability of selected numerical methods to represent stably stratified flows over horizontal strip [4] and hill type 2D obstacles [1, 3] with generation of internal waves. ACKNOWLEDGMENTS This research work was supported by the Region Provence Alpes Côte d'Azur - Modtercom project. The work was also supported by the Russian Foundation for Basic Research (grant 12-01-00128). REFERENCES [1] Chashechkin Yu.D., Mitkin V.V. Experimental study of a fine structure of 2D wakes and mixing past an obstacle in a continuously stratified fluid // Dynamics of Atmosphere and Oceans. 2001. V. 34. P. 165-187. [2] Chashechkin, Yu. D. Hydrodynamics of a sphere in a stratified fluid // Fluid Dyn. 1989. V.24(1) P. 1-7. [3] Mitkin V. V., Chashechkin Yu. D. Transformation of hanging discontinuities into vortex systems in a
The numerical analysis of labyrinth screw pump and seal
NASA Astrophysics Data System (ADS)
Zhu, Yizheng; Luo, Jin; Han, Guojun
1991-08-01
The main part of a labyrinth screw pump and seal is composed of both threads on the axle and the sleeve, which intersect at an oblique angle. A unit element surrounded by the two sets of threads has been taken as an isolated calculating area. Based on the N-S equation and the continuity equation, the centrifugal force and curvature effect have been neglected. Due to the periodical property along z-direction, it is reasonable to neglect the terms (d/dz) in the equations on the entrance and the middle cross section of the unit element. Thus, the set of equations could be reduced in a simpler form, and the coupling of x-y plane flow with z-direction could be eliminated. Therefore a quasi-state three-dimensional velocity field in the unit element space can be calculated by numerical solutions. Thus the corresponding characteristics of the labyrinth pump and seal may be obtained.
Numerical analysis of wet separation of particles by density differences
NASA Astrophysics Data System (ADS)
Markauskas, D.; Kruggel-Emden, H.
2017-07-01
Wet particle separation is widely used in mineral processing and plastic recycling to separate mixtures of particulate materials into further usable fractions due to density differences. This work presents efforts aiming to numerically analyze the wet separation of particles with different densities. In the current study the discrete element method (DEM) is used for the solid phase while the smoothed particle hydrodynamics (SPH) is used for modeling of the liquid phase. The two phases are coupled by the use of a volume averaging technique. In the current study, simulations of spherical particle separation were performed. In these simulations, a set of generated particles with two different densities is dropped into a rectangular container filled with liquid. The results of simulations with two different mixtures of particles demonstrated how separation depends on the densities of particles.
Analysis of free turbulent shear flows by numerical methods
NASA Technical Reports Server (NTRS)
Korst, H. H.; Chow, W. L.; Hurt, R. F.; White, R. A.; Addy, A. L.
1973-01-01
Studies are described in which the effort was essentially directed to classes of problems where the phenomenologically interpreted effective transport coefficients could be absorbed by, and subsequently extracted from (by comparison with experimental data), appropriate coordinate transformations. The transformed system of differential equations could then be solved without further specifications or assumptions by numerical integration procedures. An attempt was made to delineate different regimes for which specific eddy viscosity models could be formulated. In particular, this would account for the carryover of turbulence from attached boundary layers, the transitory adjustment, and the asymptotic behavior of initially disturbed mixing regions. Such models were subsequently used in seeking solutions for the prescribed two-dimensional test cases, yielding a better insight into overall aspects of the exchange mechanisms.
Numerical analysis of turbulent coaxial flow with internal heat generation
NASA Technical Reports Server (NTRS)
Lin, A.; Weinstein, H.
1981-01-01
A computational method with which to obtain a physical understanding of the turbulent field of two coaxial jets entering an axisymmetric chamber is developed. Even the laminar field of this flow is quite complicated. This is due to the many different domains which exist in the field especially in the entrance region. Physically, three regions may be identified: the wall region, the initial region near the axis of symmetry and the mixing region. Advancing downstream, these regions change relative size with the ratio of the two jets' mass fluxes as the main parameter. The turbulent field of these flows is much more complicated due to the difference in the effective transport coefficients and turbulence level from region to region. However, being aware beforehand of the complications and the different regions of this field, the appropriate turbulence model and numerical scheme can be adjusted to treat the problem.
Numerical analysis on nanoparticles-laden gas film thrust bearing
NASA Astrophysics Data System (ADS)
Yang, Zhiru; Diao, Dongfeng; Yang, Lei
2013-07-01
Nanoparticles can be taken as additives and added into various fluids to improve their lubricating performances. At present, researches in this area are mainly concentrated on the improvement effects of nanoparticles on the lubricating performances of liquid such as oil and water. Nanoparticles will also affect gas lubrication, but few related studies have been reported. Nanoparticles-laden gas film (NLGF) is formed when adding nanoparticles into gas bearing. Then, the lubricating performances of gas bearing including pressure distribution and load-carrying capacity will change. The variations of pressure distribution and load-carrying capacity in nanoparticles-laden gas film thrust bearing are investigated by numerical method. Taking account of the compressibility of gas and the interactions between gas and nanoparticles, a computational fluid dynamics model based on Navier-Stokes equations is applied to simulate the NLGF flow. The effects of inlet nanoparticles volume fraction and orifice radius on film pressure distribution and load-carrying capacity of the NLGF are calculated. The numerical calculation results show that both of the film land pressure and the maximum film pressure both increase when the nanoparticles are added into gas bearing, and the film pressures increase with the rising of the inlet nanoparticles volume fraction. The nanoparticles have an enhancement effect on load-carrying capacity of the studied bearing, and the enhancement effect becomes greater as the film thickness decrease. Therefore, nanoparticles can effectively improve the lubricating performance of gas bearing. The proposed research provides a theoretical basis for the design of new-type nanoparticles-laden gas film bearings.
NASA Astrophysics Data System (ADS)
Avellar, J.; Duarte, L. G. S.; da Mota, L. A. C. P.; de Melo, N.; Skea, J. E. F.
2012-09-01
A set of Maple routines is presented, fully compatible with the new releases of Maple (14 and higher). The package deals with the numerical evolution of dynamical systems and provide flexible plotting of the results. The package also brings an initial conditions generator, a numerical solver manager, and a focusing set of routines that allow for better analysis of the graphical display of the results. The novelty that the package presents an optional C interface is maintained. This allows for fast numerical integration, even for the totally inexperienced Maple user, without any C expertise being required. Finally, the package provides the routines to calculate the fractal dimension of boundaries (via box counting). New version program summary Program Title: Ndynamics Catalogue identifier: %Leave blank, supplied by Elsevier. Licensing provisions: no. Programming language: Maple, C. Computer: Intel(R) Core(TM) i3 CPU M330 @ 2.13 GHz. Operating system: Windows 7. RAM: 3.0 GB Keywords: Dynamical systems, Box counting, Fractal dimension, Symbolic computation, Differential equations, Maple. Classification: 4.3. Catalogue identifier of previous version: ADKH_v1_0. Journal reference of previous version: Comput. Phys. Commun. 119 (1999) 256. Does the new version supersede the previous version?: Yes. Nature of problem Computation and plotting of numerical solutions of dynamical systems and the determination of the fractal dimension of the boundaries. Solution method The default method of integration is a fifth-order Runge-Kutta scheme, but any method of integration present on the Maple system is available via an argument when calling the routine. A box counting [1] method is used to calculate the fractal dimension [2] of the boundaries. Reasons for the new version The Ndynamics package met a demand of our research community for a flexible and friendly environment for analyzing dynamical systems. All the user has to do is create his/her own Maple session, with the system to
Ernest A. Mancini
2003-09-11
The principal research effort for Year 1 of the project is data compilation and the determination of the tectonic and depositional histories of the North Louisiana Salt Basin. In the first three (3) to six (6) months of Year 1, the research focus is on data compilation and the remainder of the year the emphasis is on the tectonic and depositional histories of the basin. No major problems have been encountered to date, and the project is on schedule.
Ernest A. Mancini
2003-11-11
The principal research effort for Year 1 of the project is data compilation and the determination of the tectonic and depositional histories of the North Louisiana Salt Basin. In the first three (3) to six (6) months of Year 1, the research focus is on data compilation and the remainder of the year the emphasis is on the tectonic and depositional histories of the basin. No major problems have been encountered to date, and the project is on schedule.
Kohles, K.M.; Potts, J. ); Reid, F.S.
1991-03-01
The Washakie and Red Desert basins comprise the eastern portion of the Greater Green River basins of southwestern Wyoming. Stratigraphically the basins are dominated by a thick package of Cretaceous clastic sediments, as much as 16,000 ft thick, which resulted from several major transgressive-regressive cycles. Upper Cretaceous strata deposited during the latest cycle contain extensive deposits of commercial hydrocarbons, particularly gas. Much of the present structural configuration of the area is the result of the Laramide Orogeny in Late Cretaceous time. To facilitate a comprehensive geological analysis of the area a computerized subsurface data base was constructed from available well logs for approximately 3,000 wells in the Washakie and Red Desert basins. This data base contains correlated tops for most of the major Upper Cretaceous stratigraphic units, including selected subdivisions and net sand thickness values. Consistent correlations were achieved through the use of a tight, loop-tied cross section and key well network containing over 400 correlated well-logs. A complete suite of structure contour maps on all correlated horizons was generated from the data base with commercially available software. These maps, along with selected computer-generated structural cross sections, reveal a detailed subsurface picture of the Washakie and Red Desert basins. Isopachous maps of selected intervals were also produced to illustrate the Late Cretaceous depositional history of the area.
Numerical Analysis on Neutron Shielding Structure of ITER Vacuum Vessel
NASA Astrophysics Data System (ADS)
Liu, Changle; Wu, Songtao; Yu, Jie; Sheng, Daolin
2008-06-01
The neutron shielding component of ITER (International Thermonuclear Experimental Reactor) vacuum vessel is a kind of structure resembling a wall in appearance. A FE (finite element) model is set up by using ANSYS code in terms of its structural features. Static analysis, thermal expansion analysis and dynamic analysis are performed. The static results show that the stress and displacement distribution are allowable, but the high stress appears in the junction between the upper and lower parts. The modal analysis indicates that the biggest deformation exists in the port area. Through modal superposition, the single-point response has been found with the lower rank frequency of the acceleration seismic response spectrum. But the deformation and the stress values are within the permissible limit. The analysis results would benefit the work in the next step and provide some reference for the implementation of the engineering plan in the future.
NASA Technical Reports Server (NTRS)
Han, Samuel S.; Schafer, Charles F.
1988-01-01
A numerical analysis of transient heat and solute transport across a rectangular cavity with combined horizontal temperature and concentration gradients is performed by a numerical method based on the SIMPLE. Numerical results show that the average Nusselt and Sherwood numbers both decrease markedly when the solutal and thermal buoyancy forces act in the opposite directions. When the solutal and thermal buoyancy forces act in the same directions, however, the average Sherwood number increases significantly and yet the average Nusselt number decreases slightly.
Wilkins, D.W.
1986-01-01
The Southwest Alluvial Basins study is part of the National Regional Aquifer-Systems Analysis program. Twenty-two structural basins extend from the San Luis Basin in southern Colorado to the Presidio Basin in western Texas. Closed surface-water basins west of the Guadalupe Mountains and east of the Peloncillo Mountains are included in the study. The study area is bounded on the east by predominately Precambrian and Paleozoic rocks. Tertiary and Quaternary volcanics also are present. Tertiary and Quaternary volcanic rocks, and also Mesozoic rocks west of the Espanola and Albuquerque-Belen Basins, form the west boundary. The east and west boundary units converge at the north end of the study area to form the north boundary. The study area extends south to the international border between the United States and Mexico. The Santa Fe Group sediments of late Oligocene to middle Pleistocene age comprise the main aquifer in the area. Estimated maximum depths of sediments in the rift basins range from 8,000 ft in the Tularosa-Hueco Basin to 30,000 ft in the San Luis Basin. The average thickness of sediments in closed basins is about 4,000 ft. Santa Fe deposits are composed of layers of gravel, sand, silt, and clay interbedded with local volcanic lows of tuffs. Lacustrine deposits are more prevalent in the closed basins. Wells produce as much as 2,000 gal of water/min. Poteniometric-surface altitudes for 1971-82 indicate that water recharges in the highland areas around the basins and discharges in the center of valleys. Water generally flows from the east and west southward along the axis of the valleys. Groundwater quality for the region has been zoned into calcium sulfate, calcium chloride, magnesium sulfate, magnesium chloride; sodium sulfate, sodium chloride; sodium bicarbonate; and calcium bicarbonate, magnesium bicarbonate types. (USGS)
Analysis of meteorological and hydrological droughts in the Niger-South Basin, Nigeria
NASA Astrophysics Data System (ADS)
Oloruntade, Ajayi J.; Mohammad, Thamer A.; Ghazali, Abdul H.; Wayayok, Aimrun
2017-08-01
Information gained from drought analysis can serve as the basis for water resources planning and management under the prevailing climate change condition especially at the basin scale. The aim of this work is to apply two meteorological drought indices - Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI) and a hydrological drought index - Standardized Runoff Index (SRI) to investigate the occurrence of drought in the Niger-South Basin (NSB), a sub-catchment of the Niger River Basin in Nigeria, during the period 1970-2008. The results showed that the period between 1970 and 1981 was dominated by wet conditions; second, from 1982 to 1998, a period of droughts ranging from moderate dry to extreme dry alternated with moderate wet conditions, while the third period beginning from 1999 to 2008 displayed another round of severe droughts sparingly intercepted by occasional moderate wet conditions. High correlation values of between 0.66 (at 3-month scale) and 0.56 (at 12-month scale) show comparativeness in the performance of the two drought indices. For the hydrological drought, a severe drought was observed in 1982 and near normal and moderately wet since 1997. The higher agreement between the SRI and SPEI, suggests that hydrological droughts are more affected by temperature (warming) than precipitation (drying) in the basin. Further analysis of the frequency of the various conditions shows that it has been more of near normal conditions (> 60%), while extremely dry and wet conditions (2% each) have been very rare. However, given the projected global warming conditions, a reversal of the present normal condition might be witnessed in the nearest future, hence, the results of this study can serve as a basis for effective water resources planning and management in the basin.
Temporal precipitation trend analysis at the Langat River Basin, Selangor, Malaysia
NASA Astrophysics Data System (ADS)
Palizdan, Narges; Falamarzi, Yashar; Huang, Yuk Feng; Lee, Teang Shui; Ghazali, Abdul Halim
2015-12-01
The Langat River Basin provides fresh water for about 1.2 million people in the Langat and Klang valleys. Any change in the pattern of rainfall could affect the quantity of water in the basin. Studying the pattern of change in rainfall is crucial for managing the available water resources in the basin. Thus, in this study, for the first time, both parametric and non-parametric methods were employed to detect rainfall trend in the basin for the period 1982-2011. The trends were determined at 30 rainfall stations using the Mann-Kendall (MK) test, the Sen's slope estimator and the linear regression analysis. Lag-1 approach was utilized to test the serial correlation of the series. On the annual scale, it was found that most of the stations in the basin were characterized with insignificant trends. The significant trends were found only at the four stations, namely 44301, 44305, 44320 and 2719001. The results of the seasonal trend analysis showed that most of the stations during the northeast monsoon (NEM) and the inter monsoon 1 (INT1) seasons and half of the stations during the southwest monsoon (SWM) season experienced insignificant positive trends. To the contrary, for the inter monsoon 2 (INT2) season, majority of the stations showed negative trends. It was found that during the NEM season the station 44301, for the INT1 season stations 44301, 2719001 and 3118069 were established as having significant changes, while in the SWM season station 2917001 and during the INT2 season, the stations 2615131 and 44301 showed significant trends. It is worth mentioning that the maximum rainfall occurs in inter-monsoon seasons.
Tularosa Basin Play Fairway Analysis Data and Models
Nash, Greg
2017-07-11
This submission includes raster datasets for each layer of evidence used for weights of evidence analysis as well as the deterministic play fairway analysis (PFA). Data representative of heat, permeability and groundwater comprises some of the raster datasets. Additionally, the final deterministic PFA model is provided along with a certainty model. All of these datasets are best used with an ArcGIS software package, specifically Spatial Data Modeler.
NASA Astrophysics Data System (ADS)
Kaiser, B. O.; Scheck-Wenderoth, M.; Cacace, M.; Przybycin, A.; Lewerenz, B.
2012-04-01
Sedimentary basins provide a significant portion of geothermal energy. Making geothermal heat an effective source for sustainable energy supply requires a quantitative reserve assessment. Numerical (mathematical) models of sedimentary basins are useful tools for first-order approximations of the geothermal potential on a regional scale. The challenge for numerical investigations within complex geological sedimentary basins is that the thermal field contains superposed signals originating from several heat transport processes, different in nature but physically coupled. An additional difficulty arising from numerical simulations is the error introduced by discretizing a continuous physical system into its numerical counterpart. Different mesh resolutions may lead to different and sometimes contrasting computational findings, thus making the reliability of coupled numerical simulations at least questionable. By means of 3D numerical simulations we discriminate conductive, forced convective and free thermal convective heat transport within a complex geological setting, the Northeast German Basin. As a second step we explore the sensitivity of each heat transport process with regard to the spatial discretization. The internal geological structure of the NEGB is characterized by the presence of a highly structured Zechstein salt sequence piercing the sedimentary overburden locally. Moreover, the Zechstein salt is impervious to fluid flow and has a relative high thermal conductivity compared to the surrounding clastic sediments. Computational results show that these hydrogeological conditions exerts primary constraints on the internal hydrothermal setting of the basin. The impervious nature of the Zechstein salt inhibits groundwater flow to be effective. Accordingly, conduction is the main heat transport mechanism within the salt. In contrast, forced convective heat transport triggerd by topographic gradients affects mainly the temperature distribution within the post
NASA Astrophysics Data System (ADS)
Cai, Ximing; McKinney, Daene C.; Lasdon, Leon S.
2002-06-01
Sustainable water management in irrigation-dominated river basins attempts to ensure a long-term, stable, and flexible water supply to meet crop water demands, as well as growing municipal and industrial water demands, while mitigating negative environmental consequences. To achieve this delicate balance, new models are needed which can use indicators of sustainability to guide the decision-making process. This paper presents a new long-term modeling framework which uses quantified sustainability criteria in a long-term optimization model of a basin, ensuring risk minimization in water supply, environmental conservation, equity in water allocation, and economic efficiency in water infrastructure development. ``Current'' and ``future'' water supply and demand are combined into a coherent system which takes account of the cumulative effects of short-term water use decisions and deals with the tradeoffs between the benefits of current and future generations. The modeling framework is demonstrated with an application to the Syr Darya River Basin of central Asia. Model results show the effectiveness of this tool for policy analysis in the context of the river basin.
Minimizing Errors in Numerical Analysis of Chemical Data.
ERIC Educational Resources Information Center
Rusling, James F.
1988-01-01
Investigates minimizing errors in computational methods commonly used in chemistry. Provides a series of examples illustrating the propagation of errors, finite difference methods, and nonlinear regression analysis. Includes illustrations to explain these concepts. (MVL)
Graphic analysis of resources by numerical evaluation techniques (Garnet)
Olson, A.C.
1977-01-01
An interactive computer program for graphical analysis has been developed by the U.S. Geological Survey. The program embodies five goals, (1) economical use of computer resources, (2) simplicity for user applications, (3) interactive on-line use, (4) minimal core requirements, and (5) portability. It is designed to aid (1) the rapid analysis of point-located data, (2) structural mapping, and (3) estimation of area resources. ?? 1977.
Potentials and limits to basin stability estimation
NASA Astrophysics Data System (ADS)
Schultz, Paul; Menck, Peter J.; Heitzig, Jobst; Kurths, Jürgen
2017-02-01
Stability assessment methods for dynamical systems have recently been complemented by basin stability and derived measures, i.e. probabilistic statements whether systems remain in a basin of attraction given a distribution of perturbations. Their application requires numerical estimation via Monte Carlo sampling and integration of differential equations. Here, we analyse the applicability of basin stability to systems with basin geometries that are challenging for this numerical method, having fractal basin boundaries and riddled or intermingled basins of attraction. We find that numerical basin stability estimation is still meaningful for fractal boundaries but reaches its limits for riddled basins with holes.
Multivariate analysis of groundwater resources in Ganga-Yamuna basin (India).
Sargaonkar, Aabha P; Gupta, Apurba; Devotta, Sukumar
2008-07-01
Groundwater quality data on physico-chemical, bacteriological and heavy metal concentrations in three cities (Faridabad, Allahabad and Varanasi) in Ganga-Yamuna basin was subjected to multivariate analysis (MVA) using SPSS. The factors extracted showed high loading (> 0.3) of various parameters, such as Cl, conductivity, TDS, hardness, Na, Mg, and SO4, indicating contamination due to leaching of pollutants. Major manifest variable associated with these factors is the unorganized solid waste dumping practiced in all the cities. Bacterial contamination of hand pump samples in Allahabad is attributed to surface water-groundwater interaction. The factor with high loading of Ca and F is indicative of geological conditions of the region. Wells in Yamuna river sub-watershed exhibit less freshwater recharge, which is attributed to surface water pollution and sediment deposition in the river. Thus, the methodology for hydrogeological analysis is useful to identify critical water quality issues and possible sources of pollution in river basins.
Methods of numerical analysis of 1-dimensional 2-body problem in Wheeler-Feynman electrodynamics
NASA Astrophysics Data System (ADS)
Klimenko, S. V.; Nikitin, I. N.; Urazmetov, W. F.
2000-04-01
Numerical methods for solution of differential equations with deviating arguments describing 1-dimensional ultra-relativistic scattering of 2 identical charged particles in classical electrodynamics with half-retarded/halfadvanced interaction (Wheeler and Feynman, 1949) are developed. A bifurcation of solutions and violation of their reflectional symmetries in the region of velocities v>0.937c are found in numerical analysis.
Bradfield, A.D.
1986-01-01
Coal-mining impacts on Smoky Creek, eastern Tennessee were evaluated using water quality and benthic invertebrate data. Data from mined sites were also compared with water quality and invertebrate fauna found at Crabapple Branch, an undisturbed stream in a nearby basin. Although differences in water quality constituent concentrations and physical habitat conditions at sampling sites were apparent, commonly used measures of benthic invertebrate sample data such as number of taxa, sample diversity, number of organisms, and biomass were inadequate for determining differences in stream environments. Clustering algorithms were more useful in determining differences in benthic invertebrate community structure and composition. When data from a single season were examined, sites on tributary streams generally clustered separately from sites on Smoky Creek. These analyses compared with differences in water quality, stream size, and substrate characteristics between tributary sites and the more degraded main stem sites, indicated that numerical classification of invertebrate data can provide discharge-independent information useful in rapid evaluations of in-stream environmental conditions. 25 refs., 14 figs., 22 tabs.
Bradfield, A.D.
1986-01-01
Coal-mining impacts on Smoky Creek, eastern Tennessee were evaluated using water quality and benthic invertebrate data. Data from mined sites were also compared with water quality and invertebrate fauna found at Crabapple Branch, an undisturbed stream in a nearby basin. Although differences in water quality constituent concentrations and physical habitat conditions at sampling sites were apparent, commonly used measures of benthic invertebrate sample data such as number of taxa, sample diversity, number of organisms, and biomass were inadequate for determining differences in stream environments. Clustering algorithms were more useful in determining differences in benthic invertebrate community structure and composition. Normal (collections) and inverse (species) analyses based on presence-absence data of species of Ephemeroptera, Plecoptera, and Tricoptera were compared using constancy, fidelity, and relative abundance of species found at stations with similar fauna. These analyses identified differences in benthic community composition due to seasonal variations in invertebrate life histories. When data from a single season were examined, sites on tributary streams generally clustered separately from sites on Smoky Creek. These analyses compared with differences in water quality, stream size, and substrate characteristics between tributary sites and the more degraded main stem sites, indicated that numerical classification of invertebrate data can provide discharge-independent information useful in rapid evaluations of in-stream environmental conditions. (Author 's abstract)
NASA Astrophysics Data System (ADS)
Kim, Seonok; Wang, Sookyun; Lee, Minhee
2016-04-01
Long term containment of stored CO2 in deep geological formation will be dependent on the performance of the caprock to prevent the buoyant CO2. The study aims to identify CO2-brine-caprock interactions and develop a framework, within which, geochemical reaction in caprock due CO2 injection can be evaluated. A series of autoclave experiments were conducted with caprock from drilling cores of Pohang basin where many researches have been focused as a candidate for geological CO2 sequestration at 50℃ with 100 bar of CO2 for 15day. XRD, XRF, ICP-OES and SEM-EDS studies were performed to characterize the reaction products. Also the numerical modeling with use of Geochemist's Workbench 10.0.6 (GWB) in two stages was performed. The first one was aimed at simulating the immediate changes in the aquifer and insulating caprocks impacted by the beginning of CO2 injection (100 days), the second enabling assessment of long-term effects of sequestration (10000 years). The simulations allowed to determine the suitability of the formation for carbon dioxide storage.
Interaction of debris with a solid obstacle: numerical analysis.
Kosinska, Anna
2010-05-15
The subject of this research is the propagation of a cloud of solid particles formed from an explosion-damaged construction. The main objective is the interaction of the cloud (debris) with a solid beam located at some distance from the explosion. The mathematical model involves the flow of the gas using standard conservation equations, and this part of the model is solved numerically. The solid particles are treated as a system of solid points (so-called Lagrangian approach), whose motion is the result of the flowing gas as well as collisions with obstacles. These two issues are described respectively by Newton's second law and the hard-sphere model. The model is used to simulate various cases where the influence of different parameters like the value of the pressure of the explosion, the particle size, the number of particles and the obstacle location are investigated. The results are presented as snapshots of particle location, and also as the particle total momentum during collision with the beam. Copyright (c) 2009 Elsevier B.V. All rights reserved.
Numerical analysis of mixing enhancement for micro-electroosmotic flow
NASA Astrophysics Data System (ADS)
Tang, G. H.; He, Y. L.; Tao, W. Q.
2010-05-01
Micro-electroosmotic flow is usually slow with negligible inertial effects and diffusion-based mixing can be problematic. To gain an improved understanding of electroosmotic mixing in microchannels, a numerical study has been carried out for channels patterned with wall blocks, and channels patterned with heterogeneous surfaces. The lattice Boltzmann method has been employed to obtain the external electric field, electric potential distribution in the electrolyte, the flow field, and the species concentration distribution within the same framework. The simulation results show that wall blocks and heterogeneous surfaces can significantly disturb the streamlines by fluid folding and stretching leading to apparently substantial improvements in mixing. However, the results show that the introduction of such features can substantially reduce the mass flow rate and thus effectively prolongs the available mixing time when the flow passes through the channel. This is a non-negligible factor on the effectiveness of the observed improvements in mixing efficiency. Compared with the heterogeneous surface distribution, the wall block cases can achieve more effective enhancement in the same mixing time. In addition, the field synergy theory is extended to analyze the mixing enhancement in electroosmotic flow. The distribution of the local synergy angle in the channel aids to evaluate the effectiveness of enhancement method.
Numerical analysis for cavitation flow of marine propeller
NASA Astrophysics Data System (ADS)
Tauviqirrahman, Mohammad; Muchammad, Ismail, Rifky; Jamari, J.
2015-12-01
Concerning the environmental issue and the increase of fuel price, optimizing the fuel consumption has been recently an important subject in all industries. In marine industries one of the ways to decrease the energy consumption was by reducing the presence of cavitation on marine propeller blades. This will give a higher propulsive efficiency. This paper provides an investigation into the influence of the cavitation on a hydrodynamic performance around the propeller based on numerical method. Hydrofoil representing the blade form of propeller was of particular of interest. Two types of cavitation model were investigated with respect to the accuracy of the result and the effectiveness of the method. The results include the hydrodynamic characteristics of cavitation phenomenon like lift/drag variation with respect to the cavity extent. It was found that a high accuracy and low computational time is achieved when the cavitation model of Zwart-Gerber-Belamri is used. The interesting outcome of this study is that the results can be used as a good evaluation tool for high marine propeller performance.
Numerical Simulation and Chaotic Analysis of an Aluminum Holding Furnace
NASA Astrophysics Data System (ADS)
Wang, Ji-min; Zhou, Yuan-yuan; Lan, Shen; Chen, Tao; Li, Jie; Yan, Hong-jie; Zhou, Jie-min; Tian, Rui-jiao; Tu, Yan-wu; Li, Wen-ke
2014-12-01
To achieve high heat efficiency, low pollutant emission and homogeneous melt temperature during thermal process of secondary aluminum, taking into account the features of aluminum alloying process, a CFD process model was developed and integrated with heat load and aluminum temperature control model. This paper presented numerical simulation of aluminum holding furnaces using the customized code based on FLUENT packages. Thermal behaviors of aluminum holding furnaces were investigated by probing into main physical fields such as flue gas temperature, velocity, and concentration, and combustion instability of aluminum holding process was represented by chaos theory. The results show that aluminum temperature uniform coefficient firstly decreases during heating phase, then increases and reduces alternately during holding phase, lastly rises during standing phase. Correlation dimension drops with fuel velocity. Maximal Lyapunov exponent reaches to a maximum when air-fuel ratio is close to 1. It would be a clear comprehension about each phase of aluminum holding furnaces to find new technology, retrofit furnace design, and optimize parameters combination.
Numerical Analysis Of Three Component Induction Logging In Geothermal Reservoirs
Dr. David L. Alumbaugh
2002-01-09
This project is supporting the development of the ''Geo-Bilt'', geothermal electromagnetic-induction logging tool that is being built by ElectroManetic Instruments, Inc. The tool consists of three mutually orthogonal magnetic field antennas, and three-component magnetic field receivers located at different distances from the source. In its current configuration, the source that has a moment aligned along the borehole axis consists of a 1m long solenoid, while the two trans-axial sources consist of 1m by 8cm loops of wire. The receivers are located 2m and 5m away from the center of the sources, and five frequencies from 2 kHz to 40 kHz are being employed. This study is numerically investigating (1) the effect of the borehole on the measurements, and (2) the sensitivity of the tool to fracture zone-geometries that might be encountered in a geothermal field. The benefits of the results are that they will lead to a better understanding of the data that the tool produces during its testing phase and an idea of what the limitations of the tool are.
Parameter Calibration and Numerical Analysis of Twin Shallow Tunnels
NASA Astrophysics Data System (ADS)
Paternesi, Alessandra; Schweiger, Helmut F.; Scarpelli, Giuseppe
2017-05-01
Prediction of displacements and lining stresses in underground openings represents a challenging task. The main reason is primarily related to the complexity of this ground-structure interaction problem and secondly to the difficulties in obtaining a reliable geotechnical characterisation of the soil or the rock. In any case, especially when class A predictions fail in forecasting the system behaviour, performing class B or C predictions, which rely on a higher level of knowledge of the surrounding ground, can represent a useful resource for identifying and reducing model deficiencies. The case study presented in this paper deals with the construction works of twin-tube shallow tunnels excavated in a stiff and fine-grained deposit. The work initially focuses on the ground parameter calibration against experimental data, which together with the choice of an appropriate constitutive model plays a major role in the assessment of tunnelling-induced deformations. Since two-dimensional analyses imply initial assumptions to take into account the effect of the 3D excavation, three-dimensional finite element analyses were preferred. Comparisons between monitoring data and results of numerical simulations are provided. The available field data include displacements and deformation measurements regarding both the ground and tunnel lining.
Containment steam blowdown analysis : experimental and numerical comparisons.
NguyenLe, Q.; Ishii, M.; Reactor Analysis; Purdue Univ.
1999-01-01
This paper compares the numerical simulation with the experimental data of a steam blowdown event in a light water reactor containment building. A three step approach was used to analyze the steam jet behavior. First, the temperature and pressure data of a steam blowdown event was measured at the Purdue University Multi-Dimensional Integrated Test Assembly (PUMA), a scaled model of the General Electric Simplified Boiling Water Reactor. Second, a 1-dimensonial, system level RELAP5/Mod3.2 model of the steam blowdown event was created and the results used to set the initial conditions for the PUMA blowdown experiments. Finally, 2-dimensional and 3-dimensional CFD models of the discharged steam jets were computed using PHOENICS, a commercially available CFD package. It was found that RELAP5 is reasonably capable in predicting the general temperature and pressure trends in the RPV. However, due to modeling compromises and the code's built-in capabilities, RELAP5 1-dimensional predictions of containment temperature and pressure did not compare well with measured data. On the other hand, with minor modfications to the k-{var_epsilon} turbulence model, the 2-dimensional and 3-dimensional PHOENICS CFD solutions compared extremely well with the measured data.
A Hybrid Numerical Analysis Method for Structural Health Monitoring
NASA Technical Reports Server (NTRS)
Forth, Scott C.; Staroselsky, Alexander
2001-01-01
A new hybrid surface-integral-finite-element numerical scheme has been developed to model a three-dimensional crack propagating through a thin, multi-layered coating. The finite element method was used to model the physical state of the coating (far field), and the surface integral method was used to model the fatigue crack growth. The two formulations are coupled through the need to satisfy boundary conditions on the crack surface and the external boundary. The coupling is sufficiently weak that the surface integral mesh of the crack surface and the finite element mesh of the uncracked volume can be set up independently. Thus when modeling crack growth, the finite element mesh can remain fixed for the duration of the simulation as the crack mesh is advanced. This method was implemented to evaluate the feasibility of fabricating a structural health monitoring system for real-time detection of surface cracks propagating in engine components. In this work, the authors formulate the hybrid surface-integral-finite-element method and discuss the mechanical issues of implementing a structural health monitoring system in an aircraft engine environment.
Numerical Analysis of Thermal Comfort at Urban Environment
NASA Astrophysics Data System (ADS)
Papakonstantinou, K.; Belias, C.
2009-08-01
The present paper refers to the numerical simulation of air velocity at open air spaces and the conducting thermal comfort after the evaluation of the examined space using CFD methods, taking into account bioclimatic principles at the architectural design. More specially, the paper draws attention to the physical procedures governing air movement at an open environment area in Athens (athletic park), named "Serafeio Athletic and Cultural Centre," trying to form them in such way that will lead to the thermal comfort of the area's visitors. The study presents a mathematical model, implemented in a general computer code that can provide detailed information on velocity, prevailing in three-dimensional spaces of any geometrical complexity. Turbulent flow is simulated and buoyancy effects are taken into account. This modelling procedure is intended to contribute to the effort towards designing open areas, such as parks, squares or outdoor building environments, using thermal comfort criteria at the bioclimatic design. A computer model of this kind will provide the architects or the environmental engineers with powerful and economical means of evaluating alternative spaces' designs.
Numerical Analysis of Thermal Comfort at Open Air Spaces
NASA Astrophysics Data System (ADS)
Papakonstantinou, K.; Belias, C.; Pantos-Kikkos, S.; Assana, A.
2008-09-01
The present paper refers to the numerical simulation of air velocity at open air spaces and the conducting thermal comfort after the evaluation of the examined space using CFD methods, taking into account bioclimatic principles at the architectural design. More specially, the paper draws attention to the physical procedures governing air movement at an open environment area in Athens (urban park), named "Attiko Alsos," trying to form them in such way that will lead to the thermal comfort of the area's visitors. The study presents a mathematical model, implemented in a general computer code that can provide detailed information on velocity, prevailing in three-dimensional spaces of any geometrical complexity. Turbulent flow is simulated and buoyancy effects are taken into account. This modelling procedure is intended to contribute to the effort towards designing open areas, such as parks, squares or outdoor building environments, using thermal comfort criteria at the bioclimatic design. A computer model of this kind will provide the architects or the environmental engineers with powerful and economical means of evaluating alternative spaces' designs.
Numerical Modelling and Analysis of Flow through Aquatic Canopies
NASA Astrophysics Data System (ADS)
Etminan Farooji, V.; Lowe, R.; Ghisalberti, M.
2016-02-01
The ability of coastal vegetation such as seagrasses and mangrove forests to dissipate wave energy is well documented in both field and laboratory studies. Quantifying this transformation of wave properties is critical for predicting coastal hydrodynamics accurately, and modelling these transformations is required to quantify the role that coastal vegetation plays in reducing storm damage and coastal erosion. This has led to the development of a number of wave-vegetation hydrodynamic formulations, which account for the influence of plant structure on wave attenuation through the vegetation drag coefficient. There is very limited knowledge of the drag coefficient of aquatic vegetation and it is typically treated only as a calibration parameter; that is, adjusted to minimize the difference between predicted and observed wave heights. In this study, computational fluid dynamics methods are used to obtain a better understanding of flow and energy dissipation inside aquatic canopies. The results show an increase in the force exerted on canopy elements as the canopy density increases. The results of the numerical simulations have been used to analyse various small scale flow characteristics affecting the drag force and investigate the mechanisms that govern the flow behaviour. The results of this study can be employed to improve the accuracy of wave dissipation modelling within coastal models.
Numerical analysis of extensional flow through the pharyngeal duct
NASA Astrophysics Data System (ADS)
Preciado-Méndez, M.; Salinas-Vázquez, M.; Vicente, W.; Brito-de la Fuente, E.; Ascanio, G.
2017-01-01
The flow through the pharynx from the glossopalatal junction (GPJ) to the upper esophageal sphincter (UES) has been numerically investigated with a non-Newtonian fluid obeying the power-law with similar rheological indices to a contrast medium used in videofluroscopy. For that purpose, a three-dimensional model of the transport of food bolus along the pharynx has been proposed using the immersed boundaries method, which allow representing the shape of the pharynx using Cartesian grids. The pharyngeal wall has been considered to be an elastic membrane. Flow fields in terms of the axial velocity, pressure, shear rate and strain rate were obtained. Results show that the highest velocity concentrates in the central stream as the fluid enters into the pharynx. In addition, as the flow quits the pharynx, a recirculation zone appears inside the cavity, resulting in low velocity zone, which increases with the coefficient of elasticity. A strong dependence on the coefficient of elasticity was observed on the pressure fields; so that as such a coefficient increases, the pressure in the pharyngeal wall will increase. It has been also observed that the bolus head travels faster than the bolus tail, which indicates that the bolus is not only subjected to shear but also to elongation. Results from this work can be further used for a rheological characterization (shear and extension) of oral nutritional supplements for patients suffering from swallowing disorders.
Numerical and experimental analysis of instability phenomena in pump turbines
NASA Astrophysics Data System (ADS)
Gentner, Ch; Sallaberger, M.; Widmer, Ch; Braun, O.; Staubli, T.
2012-11-01
Today, utilities operating pump turbines require fast and frequent changes between pumping and generating modes as well as extended operation at off-design conditions. Operation of the units in unstable areas of the machine characteristic is not acceptable and may lead to self-excited vibration of the hydraulic system. Two main features of unstable behaviour of pump turbines are known. One sometimes occurs in generating mode at low load off-design operation close to runaway conditions (S-shape of the turbine characteristic) and the other one shows in pump operation as a drop in head as the flow is reduced (saddle-type pump instability of head curve). If the stability characteristics of a pump turbine need to be known already at the design stage of the runner, numerical flow simulation (computational fluid dynamics, CFD) is the most promising tool. As the characteristics of the flow near the stability limit are highly unsteady, steady state CFD, as it is usually applied for the runner design, does not deliver the necessary insight into the flow field. In order to analyse the flow field in runner and diffuser of a pump turbine in the unstable areas of operation, ANDRITZ HYDRO has evaluated several CFD procedures with different approaches for the calculation of the described instabilities in pump and turbine operation. The results of the unsteady flow calculation are compared with model test results.
Numerical Analysis of Weak Random Drift in a Cline
Luskin, Mitchell; Nagylaki, Thomas
1979-01-01
The equilibrium state of a diffusion model for weak random genetic drift in a cline is analyzed numerically. The monoecious organism occupies an unbounded linear habitat with constant, uniform population density. Migration is homogeneous, symmetric, and independent of genotype. A single diallelic locus with a step environment is investigated in the absence of dominance and mutation. The ratio of the variance of either gene frequency to the product of the expected gene frequencies decreases monotonically to a non-zero constant. The correlation between the gene frequencies at two points decreases monotonically to zero as the separation is increased with the average position fixed; the decrease is asymptotically exponential. The correlation decreases monotonically to a positive constant depending on the separation as the average position increasingly deviates from the center of the cline with the separation fixed. The correlation also decreases monotonically to zero if one of the points is fixed and the other is moved outward in the habitat, the ultimate decrease again being exponential. All the results are parameter free. Some asymptotic formulae are derived analytically. PMID:17248919
A numerical model for dynamic wave rotor analysis
NASA Technical Reports Server (NTRS)
Paxson, D. E.
1995-01-01
A numerical model has been developed which can predict the dynamic (and steady state) performance of a wave rotor, given the geometry and time dependent boundary conditions. The one-dimensional, perfect gas, CFD based code tracks the gasdynamics in each of the wave rotor passages as they rotate past the various ducts. The model can operate both on and off-design, allowing dynamic behavior to be studied throughout the operating range of the wave rotor. The model accounts for several major loss mechanisms including finite passage opening time, fluid friction, heat transfer to and from the passage walls, and leakage to and from the passage ends. In addition, it can calculate the amount of work transferred to and from the fluid when the flow in the ducts is not aligned with the passages such as occurs in off-design operation. Since it is one-dimensional, the model runs reasonably fast on a typical workstation. This paper will describe the model and present the results of some transient calculations for a conceptual four port wave rotor designed as a topping cycle for a small gas turbine engine.
Numerical Analysis including Pressure Drop in Oscillating Water Column Device
NASA Astrophysics Data System (ADS)
das Neves Gomes, Mateus; Domingues dos Santos, Elizaldo; Isoldi, Liércio André; Rocha, Luiz Alberto Oliveira
2015-06-01
The wave energy conversion into electricity has been increasingly studied in the last years. There are several proposed converters. Among them, the oscillatingwater column (OWC) device has been widespread evaluated in literature. In this context, the main goal of this work was to perform a comparison between two kinds of physical constraints in the chimney of the OWC device, aiming to represent numerically the pressure drop imposed by the turbine on the air flow inside the OWC. To do so, the conservation equations of mass,momentumand one equation for the transport of volumetric fraction were solved with the finite volume method (FVM). To tackle thewater-air interaction, the multiphase model volume of fluid (VOF)was used. Initially, an asymmetric constraint inserted in chimney duct was reproduced and investigated. Subsequently, a second strategywas proposed,where a symmetric physical constraint with an elliptical shapewas analyzed. Itwas thus possible to establish a strategy to reproduce the pressure drop in OWC devices caused by the presence of the turbine, as well as to generate its characteristic curve.
Numerical analysis of dipole sound source around high speed trains.
Takaishi, Takehisa; Sagawa, Akio; Nagakura, Kiyoshi; Maeda, Tatsuo
2002-06-01
As the maximum speed of high speed trains increases, the effect of aeroacoustic noise on the sound level on the ground becomes increasingly important. In this paper, the distribution of dipole sound sources at the bogie section of high speed trains is predicted numerically. The three-dimensional unsteady flow around a train is solved by the large eddy simulation technique. The time history of vortices shows that unstable shear layer separation at the leading edge of the bogie section sheds vortices periodically. These vortices travel downstream while growing to finally impinge upon the trailing edge of the section. The wavelength of sound produced by these vortices is large compared to the representative length of the bogie section, so that the source region can be regarded as acoustically compact. Thus a compact Green's function adapted to the shape can be used to determine the sound. By coupling the instantaneous flow properties with the compact Green's function, the distribution of dipole sources is obtained. The results reveal a strong dipole source at the trailing edge of the bogie section where the shape changes greatly and the variation of flow with time is also great. On the other hand, the bottom of the bogie section where the shape does not change, or the leading edge and boundary layer where the variation of flow with time is small, cannot generate a strong dipole source.
Numerical analysis of the ultraprecision machining of copper
Stevens, R.; Anderson, C.; Rhorer, R.; Lucca, D.
1995-03-01
Modeling of the ultraprecision machining process can aid in the understanding of the relative importance of various process parameters and ultimately lead to improved methods of generating ultraprecision surfaces such as those required for metal optics and single crystal microelectronics substrates. Any modeling method should be verified by direct comparison to experimental data. Until recently it has been difficult to accurately measure the cutting edge, or sharpness, of a diamond tool; and therefore, most models have assumed an infinitely sharp cutting tip. With the relatively new technology of the Atomic Force Microscope (AFM), the cutting edge of single crystal diamond tools can be quantitatively described. Ultraprecision machining experiments using an AFM characterized cutting tool and orthogonal geometry have been performed. These experiments have resulted in measured cutting and thrust forces for different depths of cut in copper (Te-Cu: 99.4-99.5% Cu, 0.5-0.6% Te, 4-5 micron grain size, 225 MPa yield strength) with a well characterized diamond tool. By using this actual tool tip geometry the authors have been able to develop a model that can predict cutting and thrust forces for depths of cut on the order of the sharpness of the tool. Forces predicted by this numerical model are compared to the experimentally measured forces.
Numerical Analysis of a Radiant Heat Flux Calibration System
NASA Technical Reports Server (NTRS)
Jiang, Shanjuan; Horn, Thomas J.; Dhir, V. K.
1998-01-01
A radiant heat flux gage calibration system exists in the Flight Loads Laboratory at NASA's Dryden Flight Research Center. This calibration system must be well understood if the heat flux gages calibrated in it are to provide useful data during radiant heating ground tests or flight tests of high speed aerospace vehicles. A part of the calibration system characterization process is to develop a numerical model of the flat plate heater element and heat flux gage, which will help identify errors due to convection, heater element erosion, and other factors. A 2-dimensional mathematical model of the gage-plate system has been developed to simulate the combined problem involving convection, radiation and mass loss by chemical reaction. A fourth order finite difference scheme is used to solve the steady state governing equations and determine the temperature distribution in the gage and plate, incident heat flux on the gage face, and flat plate erosion. Initial gage heat flux predictions from the model are found to be within 17% of experimental results.
A general numerical analysis program for the superconducting quasiparticle mixer
NASA Technical Reports Server (NTRS)
Hicks, R. G.; Feldman, M. J.; Kerr, A. R.
1986-01-01
A user-oriented computer program SISCAP (SIS Computer Analysis Program) for analyzing SIS mixers is described. The program allows arbitrary impedance terminations to be specified at all LO harmonics and sideband frequencies. It is therefore able to treat a much more general class of SIS mixers than the widely used three-frequency analysis, for which the harmonics are assumed to be short-circuited. An additional program, GETCHI, provides the necessary input data to program SISCAP. The SISCAP program performs a nonlinear analysis to determine the SIS junction voltage waveform produced by the local oscillator. The quantum theory of mixing is used in its most general form, treating the large signal properties of the mixer in the time domain. A small signal linear analysis is then used to find the conversion loss and port impedances. The noise analysis includes thermal noise from the termination resistances and shot noise from the periodic LO current. Quantum noise is not considered. Many aspects of the program have been adequately verified and found accurate.
[Numerical analysis of morphological variation of germplasm resources of dioscorea].
Huang, Yu-Xian; Wang, Feng-Qing; Du, Jia-Fang; Hua, Shu-Mei; Lei, Fu-Gui; Xu, Xu-Ming; Liang, Kang-Jing; Zhang, Zhong-Yi
2013-02-01
Botanical characters of germplasm resources of Dioscorea were observed and compared, which could to offer reference for its genetic improvement, germplasm resource identification and classification. Based on field cultivation, twenty-four morphological traits of ninety-four Dioscorea germplasm resources were observed or determined. And the morphological differences among germplasm resources were compared by principal component analysis and cluster analysis. There were ample morphological diversity in the twenty-four traits, in especially in leaf size and tuber characters of the ninety-four Dioscorea germplasm resources. The first seven principal components which accounted for 80. 957% of total variance were extracted from the principal component analysis. The ninety-four germplasm resources could be divided into four clusters, which belonging to Dioscorea opposite, D. persimili, D. fordii and D. alata respectively. There were large morphological variation among germplasm resources on Dioscorea. Identification of germplasm resources of Dioscorea should focus on leaf size and tuber characters.
Geotechnical Analysis of Five Shelby Tube Samples from H-Area Retention Basin
Langton, C.A.
1999-06-02
Geotechnical and geochemical analyses were performed on five Shelby tube samples collected in the H-Area Retention Basin (HRB) during July and August of 1998. The samples were collected as part of the HRB characterization study. The test results, which are documented in this report, will be used to support the HRB contaminant fate and transport modeling/analysis and to evaluate remedial options. The results will also be used as a base line for future treatability studies.
Numerical analysis of electromagnetic cascades in emulsion chambers
NASA Technical Reports Server (NTRS)
Plyasheshnikov, A. V.; Vorobyev, K. V.
1985-01-01
A new calculational scheme of the Monte Carlo method assigned for the investigation of the development of high and extremely high energy electromagnetic cascades (EMC) in the matter was elaborated. The scheme was applied to the analysis of angular and radial distributions of EMC electrons in the atmosphere. By means of this scheme the EMC development in dense medium is investigated and some preliminary data are presented on the behavior of EMC in emulsion chambers. The results of more detailed theoretical analysis of the EMC development in emulsion chambers are discussed.
Numerical analysis of electrically tunable aspherical optofluidic lenses.
In this work, we use the numerical simulation platform Zemax to investigate the optical properties of electrically tunable aspherical liquid lenses, as we recently reported in an experimental study [
2016-06-27
In this work, we use the numerical simulation platform Zemax to investigate the optical properties of electrically tunable aspherical liquid lenses, as we recently reported in an experimental study [
Numerical Fracture Analysis of Cryogenically Treated Alloy Steel Weldments
NASA Astrophysics Data System (ADS)
Rasool Mohideen, S.; Thamizhmanii, S.; Fatah, M. M. Muhammed Abdul; Saidin, W. Najmuddin W.
2016-02-01
Cryogenic treatment is being used commercially in the industries in the last two decades for improving the life of many engineering component such as bearings and cutting tools. Though their influence in improving the wear resistance of tool materials is well established, the effect of treatment on weldments is not much investigated. In the present work, a two dimensional finite element analysis was carried out on the compact tension specimen model for simulating the treatment process and to study the fracture behaviour. The weldments were modelled by thermo- mechanical coupled field analysis for simulating he temperature distribution in the model during weld pool cooling and introducing thermal stresses due to uneven contraction and cooling. The model was subjected to cryogenic treatment by adopting radiation effect. The fracture analysis was carried out using Rice's J- Integral approach. The analysis produced a similar outcome of experimental results i.e. Increase in the fracture toughness of the specimen after cryogenic treatment in the heat affected zone of weldment.
Numerical Analysis of the Bending Properties of Cathay Poplar Glulam
Gao, Ying; Wu, Yuxuan; Zhu, Xudong; Zhu, Lei; Yu, Zhiming; Wu, Yong
2015-01-01
This paper presents the formulae and finite element analysis models for predicting the Modulus of Elastic (MOE) and Modulus of Rupture (MOR) of Cathay poplar finger-jointed glulam. The formula of the MOE predicts the MOE of Cathay poplar glulam glued with one-component polyurethane precisely. Three formulae are used to predict the MOR, and Equation (12) predicts the MOR of Cathay poplar glulam precisely. The finite element analysis simulation results of both the MOE and MOR are similar to the experimental results. The predicted results of the finite element analysis are shown to be more accurate than those of the formulae, because the finite element analysis considers the glue layers, but the formulae do not. Three types of typical failure modes due to bending were summarized. The bending properties of Cathay poplar glulam were compared to those of Douglas fir glulam. The results show that Cathay poplar glulam has a lower stiffness, but a marginally higher strength. One-component polyurethane adhesive is shown to be more effective than resorcinol formaldehyde resin adhesive for Cathay poplar glulam. This study shows that Cathay poplar has the potential to be a glulam material in China. PMID:28793619
Numerical Methods for Creep Analysis in Geotechnical Problems.
1981-12-01
relation- ships of the theory of curvilinear coordinates provide a general expression for the area, Marsden and Tromba (1975). pp 314. viz. Az) = 2 + 6(Xz...National Laboratories, 1978. Kuske, A. and Robertson, G. Photoelastic Stress Analysis. Wiley Interscience, 1974. Marsden, J.E., and Tromba , A.J., Vector
Numerical Methods for Classical Sampled-System Analysis
NASA Technical Reports Server (NTRS)
Frisch, H. P.; Bauer, F. H.
1986-01-01
SAMSAN provides control-system analyst with self-consistent computer algorithms that support large-order control-system design and evaluation studies. Emphasizes sampled-system analysis. SAMSAN reduces burden on analyst by providing set of algorithms well tested and documented and readily integrated for solving control-system problems.
Modern Numerical Methods for Classical Sampled System Analysis-SAMSAN
NASA Technical Reports Server (NTRS)
Frisch, H. P.
1984-01-01
SAMSAN aids control-system analyst by providing self-consistent set of computer algorithms that support large-order control-system design and evaluation studies, with emphasis placed on sampled system analysis. Program provides set of algorithms readily integrated for solving control-system problems.
An analysis of the carbon balance of the Arctic Basin from 1997 to 2006
McGuire, A.D.; Hayes, D.J.; Kicklighter, D.W.; Manizza, M.; Zhuang, Q.; Chen, M.; Follows, M.J.; Gurney, K.R.; McClelland, J.W.; Melillo, J.M.; Peterson, B.J.; Prinn, R.G.
2010-01-01
This study used several model-based tools to analyse the dynamics of the Arctic Basin between 1997 and 2006 as a linked system of land-ocean-atmosphere C exchange. The analysis estimates that terrestrial areas of the Arctic Basin lost 62.9 Tg C yr-1 and that the Arctic Ocean gained 94.1 Tg C yr-1. Arctic lands and oceans were a net CO2 sink of 108.9 Tg C yr-1, which is within the range of uncertainty in estimates from atmospheric inversions. Although both lands and oceans of the Arctic were estimated to be CO2 sinks, the land sink diminished in strength because of increased fire disturbance compared to previous decades, while the ocean sink increased in strength because of increased biological pump activity associated with reduced sea ice cover. Terrestrial areas of the Arctic were a net source of 41.5 Tg CH4 yr-1 that increased by 0.6 Tg CH4 yr-1 during the decade of analysis, a magnitude that is comparable with an atmospheric inversion of CH4. Because the radiative forcing of the estimated CH4 emissions is much greater than the CO2 sink, the analysis suggests that the Arctic Basin is a substantial net source of green house gas forcing to the climate system.
A Gravity Analysis of the Subsurface Structure of the Utopia Impact Basin
NASA Technical Reports Server (NTRS)
Barnerdt, W. B.
2004-01-01
The large, shallow, circular depression in Utopia Planitia has been identified as a huge impact basin, based on both geological evidence and detailed analysis of MOLA topography. Its diameter (approximately 3000 km) is equivalent to that of the Hellas basin, as is its inferred age (early Noachian). However, there the similarity ends. Their appearance, both surficially and geophysically, are virtually polar opposites. Whereas Hellas is extremely deep with rough terrain and large slopes, high-precision MOLA measurements were required to unambiguously define the smooth, shallow, almost imperceptible bowl of the Utopia basin. Conversely, Utopia displays one of the largest (non-Tharsis-related) positive geoid anomalies on Mars, in contrast to a more subdued negative anomaly over Hellas. As these two features presumably formed roughly contemporaneously by similar mechanisms, it is reasonable to assume that they were originally quite similar, and that their differences are due largely to different paths of subsequent modification. The obvious source for these differences is in their elevations: Hellas is located in the southern highlands at a rim elevation of about 3km, whereas Utopia is in the lowlying northern plains, at an average elevation of 4 km. Thus Utopia has been in an especially gravitationally favorable position to be subjected to infilling, for example, by lava flows, sedimentation, or water. In fact, its floor was almost certainly the lowest point on the planet at one time, and it would have been the termination point for down-slope drainage from over two-thirds of Mars. Thus the nature of the material filling this basin has strong connections to the sedimentary and/or volcanic processes acting on Mars in the Noachian and Early Hesperian periods. In particular, it may be able to shed some light on amount and persistence of water on early Mars in general and in the Utopia basin in particular. In this study I will use the inferred early correspondence between
NASA Astrophysics Data System (ADS)
Loegering, Markus; Anka, Zahie; Rodriguez, Jorge; Marchal, Denis; di Primio, Rolando; Vallejo, Eduardo; Kohler, Guillermina; Pangaro, Francisco
2010-05-01
The analysis of a dense 2D seismic reflection dataset and 12 exploration wells data, allowed us to reconstruct the geological evolution of the Colorado Basin, offshore Argentina. We identified and mapped the major syn- and post-rift seismic sequences, and their boundaries such as unconformities and regional seismic markers, present on the continental shelf and slope (water depths from 50 to 1800 m) of the Colorado Basin. Seismic-to-well log correlations, as well as integration with biostratigraphic data provided a chrono-stratigraphic framework for the interpreted horizons. The construction of isochronal (twt) maps provided a 3D spatial visualisation of the stratigraphic relationship among the sequences. The maps show a change in configuration from the break-up unconformity (130 Ma) to the present-day seafloor. The break-up unconformity displays a central EW-elongated graben which prevails on the overlying sequences up to the Miocene. The EW Colorado basin turns NW-SE towards the East, going perpendicular to the present-day continental margin (oriented NE-SW). The strong obliquity of the basin orientation related to the direction corresponding to the opening of the South Atlantic (NE-SW) suggests a structural control from the pre-rift basement on the rift and post-rift sequences. Starting from the break-up unconformity, the history of basin filling is illustrated up to the flat seafloor. The basin sag phase is represented by the sequences deposited between the break-up unconformity and the Colorado discontinuity (Aptian to Campanian). The Campanian to Eocene successions are more or less parallel- layered suggesting sequence aggradation. The distribution of liquid/gas hydrocarbon-leakage features (i.e. gas chimneys, mud volcanoes, and seabed pockmarks) should allow the definition of potential migration pathways. In this sense, a systematic mapping of these paleo- and present-day features observed in the seismic profiles has been performed and their distribution was
NASA Astrophysics Data System (ADS)
Leever, K. A.; Matenco, L.; Garcia-Castellanos, D.; Cloetingh, S. A. P. L.
2011-04-01
The Pannonian and Dacic Basins in SE Europe are presently connected by the Danube River across the South Carpathians, to which they are in a back-arc and foreland position respectively. Part of the Paratethys realm during the Neogene, open water communication between the basins was interrupted by the Late Miocene uplift of the Carpathians. Different mechanisms have been proposed for the formation of the Danube gateway: capture of the upstream lake or an upstream river or incision of an antecedent river. Estimates on its age range from Late Miocene to Quaternary. A related issue is the effect of the large Mediterranean sea level fall related to the Messinian Salinity Crisis on the Paratethys subbasins, specifically the "isolated" Pannonian Basin. In a synthetic numerical modelling study, using a pseudo-3D code integrating tectonics, surface processes and isostasy, we addressed the causes and effects of changes in connectivity between two large sedimentary basins separated by an elevated barrier. Specifically, we aimed to find the expression of connectivity events in the sedimentary record in general and the consequences for the evolution of the Pannonian-Dacic area in particular. We studied a range of parameters including the geometry and uplift rate of the barrier, downstream sea level change and lithosphere rigidity. We found that changes in connectivity are expressed in the sedimentary record through their effect on base level in the upstream basin and supply in the downstream basin. The most important factors controlling the response are the elevation difference between the basins and the upstream accommodation space at the time of reconnection. The most pronounced effect of reconnection through lake capture is predicted for a large elevation difference and limited upstream accommodation space. Downstream increase in sediment supply is dependent on the latter rather than the reconnection event itself. Of the parameters we tested, the rigidity of the lithosphere
Numerical analysis of the non-contacting gas face seals
NASA Astrophysics Data System (ADS)
Blasiak, S.
2017-08-01
The non-contacting gas face seals are used in high-performance devices where the main requirements are safety and reliability. Compliance with these requirements is made possible by careful research and analysis of physical processes related to, inter alia, fluid flow through the radial gap and ring oscillations susceptible to being housed in the enclosure under the influence of rotor kinematic forces. Elaborating and developing mathematical models describing these phenomena allows for more and more accurate analysis results. The paper presents results of studies on stationary ring oscillations made of different types of materials. The presented results of the research allow to determine which of the materials used causes the greatest amplitude of the vibration of the system fluid film-working rings.
Numerical analysis of projectile impact in woven texile structures
NASA Technical Reports Server (NTRS)
Roylance, D.
1977-01-01
Computer codes were developed for simulating the dynamic fracture and viscoelastic constitutive response due to stress wave interaction and reflections caused by ballistic impact on woven textiles. The method, which was developed for use in the design and analysis of protection devices for personnel armor, has potential for use in studies of rotor blade burst containment at high velocity. Alterations in coding required for burst containment problems are discussed.
NASA Astrophysics Data System (ADS)
Baioni, Davide; Gallerini, Giuliano; Sgavetti, Maria
2013-04-01
The present work is focused on the distribution of landslides in Foglia river basin area (northern Marche-Romagna), using a heuristic approach supported by GIS tools for the construction of statistical analysis and spatial data. The study area is located in the Adriatic side of the northern Apennine in the boundary that marks the transition between the Marche and Emilia-Romagna regions. The Foglia river basin extends from the Apennines to the Adriatic sea with NE-SE trend occupying an area of about 708 km2. The purpose of this study is to investigate any relationships between factors related to the territory, which were taken into account and divided into classes, and landslides, trying to identify any possible existence of relationships between them. For this aim the study of landslides distribution was performed by using a GIS approach superimposing each thematic map, previously created, with landslides surveyed. Furthermore, we tried to isolate the most recurrent classes, to detect if at the same conditions there is a parameter that affects more than others, so as to recognize every direct relationship of cause and effect. Finally, an analysis was conducted by applying the model of uncertainty CF (Certainity Factor). In the Foglia river basin were surveyed a total of 2821 landslides occupy a total area of 155 km2, corresponding to 22% areal extent of the entire basin. The results of analysis carried out highlighted the importance and role of individual factors that led to the development of landslides analyzed. Moreover, this methodology may be applied to all orders of magnitude and scale without any problem by not requiring a commitment important, both from the economic point of view, and of human resources.
Application of Methods of Numerical Analysis to Physical and Engineering Data.
1980-10-15
for tbe estimated fo. Part E extends the method to include an arbitrary signal noise power function. Part F discusses a method for obtaining initial...7 AD-AI02 685 BEDFORD RESEARCH ASSOCIATES MA F/6 4/1APPLICATION OF METHODS OF NUMERICAL ANALYSIS TO PHYSICAL AND EN--ETC(U) OCT 80 R BOUCHER, T...APPLICATION OF METHODS OF NUMERICAL .) ANALYSIS TO PHYSICAL AND! ENGINEERING DATA R. Boucher T. Costello ~ P. Meehan J. Noonan Bedford Research Associates 2
NASA Astrophysics Data System (ADS)
Polovnikov, V. Yu.; Piskunov, M. V.
2014-08-01
The numerical investigation of thermal stresses within low-temperature insulation covering cryogenic pipelines and the numerical probability analysis of low-temperature insulation destruction under the condition of periodic duty were carried out. The minimal longevity values for foamed polyurethane and mineral cotton were established. The results of longevity analysis for foamed polyurethane and mineral cotton under the condition of environment temperature variation were obtained.
Numerical Analysis of Plasma Transport in Tandem Volume Magnetic Multicusp Ion Sources
1992-03-01
oDTIC ELECTE 0 ~OF NUMERICAL ANALYSIS OF PLASMA TRANSPORT IN TANDEM VOLUME MAGNETIC MULTICUSP ION SOURCES THESIS Todd Roland Vitko Captain, USAF AFIT...TANDEM VOLUME MAGNETIC MULTICUSP ION SOURCES THESIS Todd Roland Vitko Captain, USAF AFIT/GEP/ENP/92M-01 Approved for public release; distribution...unlimited. AFIT/GEP/ENP/92M-01 NUMERICAL ANALYSIS OF PLASMA TRANSPORT IN TANDEM VOLUME MAGNETIC MULTICUSP ION SOURCES THESIS Presented to the Faculty of the
Experimental and numerical analysis of Al6063 duralumin using Taylor impact test
NASA Astrophysics Data System (ADS)
Kruszka, L.; Anaszewicz, Ł.; Janiszewski, J.; Grązka, M.
2012-08-01
The paper presents results of experimental and numerical analysis of dynamic behaviour Al6063 duralumin. Dynamical experiments were made using Taylor impact test. Experimental results at next step of study were used in numerical analyses of dynamic yield stress of tested material and model parameters of the Johnson-Cook constitutive equation. The main aim of this analysis is to find out dynamical properties of Al6063 duralumin tested in Taylor impact test.
In-situ analysis of solid bitumen in coal: Examples from the Bowen Basin and the Illinois Basin
Mastalerz, Maria; Glikson, M.
2000-01-01
Solid bitumen and associated vitrinite from selected coals from the Bowen Basin and the Illinois Basin were studied using electron microprobe and micro-FTIR techniques. The coal studied covers a range of vitrinite reflectance from 0.59% to 1.33%. Carbon content in the bitumen is generally lower than in vitrinite in coals with vitrinite reflectance below 0.67%. In coals with reflectance above 0.67%, carbon content of bitumen is higher than in vitrinite, reflecting higher aromaticity due to hydrocarbon generation. Sulfur and iron content are comparable between vitrinite and bitumen. Functional group distribution suggests the presence of two types of bitumen in the Illinois Basin coals. The more aliphatic variety occurring in veins and cleats is interpreted as pre-gas generation bitumen, and the more aromatic variety filling cells and voids in inertinite as post-gas generation bitumen. (C) 2000 Elsevier Science B.V. All rights reserved.Solid bitumen and associated vitrinite from selected coals from the Bowen Basin and the Illinois Basin were studied using electron microprobe and micro-FTIR techniques. The coal studied covers a range of vitrinite reflectance from 0.59% to 1.33%. Carbon content in the bitumen is generally lower than in vitrinite in coals with vitrinite reflectance below 0.67%. In coals with reflectance above 0.67%, carbon content of bitumen is higher than in vitrinite, reflecting higher aromaticity due to hydrocarbon generation. Sulfur and iron content are comparable between vitrinite and bitumen. Functional group distribution suggests the presence of two types of bitumen in the Illinois Basin coals. The more aliphatic variety occurring in veins and cleats is interpreted as pre-gas generation bitumen, and the more aromatic variety filling cells and voids in inertinite as post-gas generation bitumen.
Asymptotic analysis of dissipative waves with applications to their numerical simulation
NASA Technical Reports Server (NTRS)
Hagstrom, Thomas
1990-01-01
Various problems involving the interplay of asymptotics and numerics in the analysis of wave propagation in dissipative systems are studied. A general approach to the asymptotic analysis of linear, dissipative waves is developed. It was applied to the derivation of asymptotic boundary conditions for numerical solutions on unbounded domains. Applications include the Navier-Stokes equations. Multidimensional traveling wave solutions to reaction-diffusion equations are also considered. A preliminary numerical investigation of a thermo-diffusive model of flame propagation in a channel with heat loss at the walls is presented.
Design of braided composite tubes by numerical analysis method
Hamada, Hiroyuki; Fujita, Akihiro; Maekawa, Zenichiro; Nakai, Asami; Yokoyama, Atsushi
1995-11-01
Conventional composite laminates have very poor strength through thickness and as a result are limited in their application for structural parts with complex shape. In this paper, the design for braided composite tube was proposed. The concept of analysis model which involved from micro model to macro model was presented. This method was applied to predict bending rigidity and initial fracture stress under bending load of the braided tube. The proposed analytical procedure can be included as a unit in CAE system for braided composites.
Quantitative numerical analysis of transient IR-experiments on buildings
NASA Astrophysics Data System (ADS)
Maierhofer, Ch.; Wiggenhauser, H.; Brink, A.; Röllig, M.
2004-12-01
Impulse-thermography has been established as a fast and reliable tool in many areas of non-destructive testing. In recent years several investigations have been done to apply active thermography to civil engineering. For quantitative investigations in this area of application, finite difference calculations have been performed for systematic studies on the influence of environmental conditions, heating power and time, defect depth and size and thermal properties of the bulk material (concrete). The comparison of simulated and experimental data enables the quantitative analysis of defects.
Numerical Analysis for the Air Flow of Cross Flow Fan
NASA Astrophysics Data System (ADS)
Sakai, Hirokazu; Tokushge, Satoshi; Ishikawa, Masatoshi; Ishihara, Takuya
There are many factors for designing the cross flow fan. Therefore, the performance of cross flow fan is not clear yet. We can analyze the transient flow of a cross flow fan using sliding mesh approach. One of the tasks using Computational Fluid Dynamics (CFD) is a way of modeling for analysis heat exchangers with cross flow fan. These tasks are very important for design. The paper has a modeling of heat exchangers and meshing the fan blades. The next tasks, we focus the ability of cross flow fan when we change the geometry of fan blades.
Numerical analysis of helium-heated methane/steam reformer
NASA Astrophysics Data System (ADS)
Mozdzierz, M.; Brus, G.; Kimijima, S.; Szmyd, J. S.
2016-09-01
One of the most promising between many high temperature nuclear reactors applications is to produce hydrogen with heat gained. The simplest and the best examined method is steam reforming of methane. The fabricated hydrogen has wide range of use, for example can be electrochemically oxidized in fuel cells. However, heat management inside methane/steam reformer is extremely important because huge temperature gradients can cause catalyst deactivation. In this work the analysis of temperature field inside helium-heated methane/steam reformer is presented. The optimal system working conditions with respect to methane conversion rate are proposed.
Mehrian, Majid Ramezani; Hernandez, Raul Ponce; Yavari, Ahmad Reza; Faryadi, Shahrzad; Salehi, Esmaeil
2016-08-01
Lake Urmia is the second largest hypersaline lake in the world in terms of surface area. In recent decades, the drop in water level of the lake has been one of the most important environmental issues in Iran. At present, the entire basin is threatened due to abrupt decline of the lake's water level and the consequent increase in salinity. Despite the numerous studies, there is still an ambiguity about the main cause of this environmental crisis. This paper is an attempt to detect the changes in the landscape structure of the main elements of the whole basin using remote sensing techniques and analyze the results against climate data with time series analysis for the purpose of achieving a more clarified illustration of processes and trends. Trend analysis of the different affecting factors indicates that the main cause of the drastic dry out of the lake is the huge expansion of irrigated agriculture in the basin between 1999 and 2014. The climatological parameters including precipitation and temperature cannot be the main reasons for reduced water level in the lake. The results show how the increase in irrigated agricultural area without considering the water resources limits can lead to a regional disaster. The approach used in this study can be a useful tool to monitor and assess the causality of environmental disaster.
NASA Astrophysics Data System (ADS)
Liu, K. K.; Li, C. H.; Cai, Y. P.; Xu, M.; Xia, X. H.
2014-05-01
In this paper, a fuzzy multi-attribute decision analysis approach (FMADAA) was developed for supporting the evaluation of water resources security in nine provinces within the Yellow River basin. A numerical approximation system and a modified left-right scoring approach were adopted to cope with the uncertainties in the acquired information. Also, four conventional multi-attribute decision analysis (MADA) methods were implemented in the evaluation model for impact evaluation, including simple weighted addition (SWA), weighted product (WP), cooperative game theory (CGT) and technique for order preference by similarity to ideal solution (TOPSIS). Moreover, several aggregation methods including average ranking procedure, Borda and Copeland methods were used to integrate the ranking results, helping rank the water resources security in those nine provinces as well as improving reliability of evaluation results. The ranking results showed that the water resources security of the entire basin was in critical condition, including the insecurity and absolute insecurity states, especially in Shanxi, Inner Mongolia and Ningxia provinces in which water resources were lower than the average quantity in China. Hence, the improvement of water eco-environment statuses in the above-mentioned provinces should be prioritized in the future planning of the Yellow River basin.
NASA Astrophysics Data System (ADS)
Kim, Y. M.; Lee, S. M.
2016-12-01
Marginal basins located between the continent and arc islands often exhibit diverse style of opening, from regions that appear to have formed by well-defined and localized spreading center to those with less obvious zones of extension and a broad magmatic emplacement in the lower crust. The difference in the mode of back-arc opening may lead to a marked difference in crustal structure including its overall thickness and mechanical strength. The Ulleung Basin (UB) in the East Sea/Sea of Japan is considered to represent a continental rifting end-member of back-arc opening. However, compared to nearby Yamato Basin (YB) and Japan Basin (JB) in the NE corner of the sea, its structure and crustal characteristics are less well understood. This study examines the marine gravity anomalies of the UB in order to delineate the variations in crustal structure. Our analysis shows that the Moho depth from the sea surface varies from 16 km at the basin center to 22 km at the margins. However, within the basin center, the inferred thickness of the crust not including sediment is more or less the same (10-12 km), by varying only about 10-20% of the total thickness, contrary to the previous suggestions. The revelation that the UB has a thick but uniform thickness crust is consistent with previous observations using ocean bottom seismometers and is similar recent findings from the nearby YB. Another important feature is that small residual mantle gravity anomaly highs (40 mGal) exist in the northern part of the basin. These small highs trend in the NNE-SSW direction and thus corresponding to the orientation of the major tectonic structures on the Korean Peninsula, raising the possibility that they are the result of localized extension and extra crustal thinning at the time of basin formation. Alternatively, the presence of small magmatic underplating at the base of the crust, perhaps similar to high velocity region in the lower crust of YB, was also considered. According to our study
Numerical Flow Analysis of a Hydraulic Gear Pump
NASA Astrophysics Data System (ADS)
Panta, Yogendra M.; Kim, Hyun W.; Pierson, Hazel M.
2007-11-01
The pressure that exists at the outlet port of a gear pump is a result of system load that was created by a resistance to the fluid flow. However, the flow pattern created inside an external gear pump by the motion of two oppositely rotating gears is deceptively complex, despite the simple geometry of the gear pump. The flow cannot be analyzed, based on a steady-state assumption that is usually employed to analyze turbo-machinery although the flow is essentially steady. Only the time-dependent, transient analysis with moving dynamic meshing technique can predict the motion of the fluid flow against the very high adverse pressure distribution. Although the complexity of analysis is inherent in all positive displacement pumps, gear pumps pose an exceptional challenge in modeling due to the fact that there are two rotating components that are housed within a stationary casing and the gears must be in contact with each other all the time. Fluent, commercially available computational fluid dynamics (CFD) software was used to analyze the flow of the gear pump. The investigation done by CFD produced significant information on flow patterns, velocity and pressure fields, and flow rates.
NASA Astrophysics Data System (ADS)
Ahn, Kuk-Hyun; Palmer, Richard
2016-09-01
Despite wide use of regression-based regional flood frequency analysis (RFFA) methods, the majority are based on either ordinary least squares (OLS) or generalized least squares (GLS). This paper proposes 'spatial proximity' based RFFA methods using the spatial lagged model (SLM) and spatial error model (SEM). The proposed methods are represented by two frameworks: the quantile regression technique (QRT) and parameter regression technique (PRT). The QRT develops prediction equations for flooding quantiles in average recurrence intervals (ARIs) of 2, 5, 10, 20, and 100 years whereas the PRT provides prediction of three parameters for the selected distribution. The proposed methods are tested using data incorporating 30 basin characteristics from 237 basins in Northeastern United States. Results show that generalized extreme value (GEV) distribution properly represents flood frequencies in the study gages. Also, basin area, stream network, and precipitation seasonality are found to be the most effective explanatory variables in prediction modeling by the QRT and PRT. 'Spatial proximity' based RFFA methods provide reliable flood quantile estimates compared to simpler methods. Compared to the QRT, the PRT may be recommended due to its accuracy and computational simplicity. The results presented in this paper may serve as one possible guidepost for hydrologists interested in flood analysis at ungaged sites.
Trend analysis of rainfall time series for Sindh river basin in India
NASA Astrophysics Data System (ADS)
Gajbhiye, Sarita; Meshram, Chandrashekhar; Mirabbasi, Rasoul; Sharma, S. K.
2016-08-01
The study of precipitation trends is critically important for a country like India whose food security and economy are dependent on the timely availability of water such as 83 % water used for agriculture sector, 12 % for industry sector and only 5 % for domestic sector. In this study, the historical rainfall data for the periods 1901-2002 and 1942-2002 of the Sindh river basin, India, were analysed for monthly, seasonal and annual trends. The conventional Mann-Kendall test (MK) and Mann-Kendall test (MMK), after the removal of the effect of all significant autocorrelation coefficients, and Sen's slope estimator were used to identify the trends. Kriging technique was used for interpolating the spatial pattern using Arc GIS 9.3. The analysis suggested significant increase in the trend of rainfall for seasonal and annual series in the Sindh basin during 1901-2002.
Copula-Based Flood Frequency Analysis at Ungauged Basin Confluences: Nashville, Tennessee
Kao, Shih-Chieh; Chang, Ni-Bin
2012-01-01
Many cities are located at or near the confluence of streams where availability of water resources may be enhanced to sustain user needs while also posing an increased flooding risk from multiple tributaries. An accurate flood frequency estimator that models the joint flood potential at a basin confluence is needed. Given that long-term flow observations are often unavailable, estimating flood frequency at ungaged basin confluences proves challenging. Through the use of copulas, this case study demonstrates how an improved flood frequency analysis can be performed for stream confluences at Nashville, TN. The approach involves four major steps including initial data quality control, fitting of marginal distributions of tributary peak flows, construction of a suitable dependence structure, and identification of flood frequency at the confluence point based on synthesized peak flows. This case study may help researchers and practitioners develop a better understanding of joint flood frequency with consideration of upstream dam regulation among several contributing watersheds.