Science.gov

Sample records for advanced combustion modes

  1. Advanced Combustion

    SciTech Connect

    Holcomb, Gordon R.

    2013-03-11

    The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

  2. Thermally Stratified Compression Ignition: A new advanced low temperature combustion mode with load flexibility

    DOE PAGES

    Lawler, Benjamin; Splitter, Derek; Szybist, James; ...

    2017-03-01

    We introduce a new advanced combustion mode, called Thermally Stratified Compression Ignition (TSCI), which uses direct water injection to control both the average temperature and the temperature distribution prior to ignition, thereby providing cycle-to-cycle control over the start and rate of heat release in Low Temperature Combustion (LTC). Experiments were conducted to fundamentally understand the effects of water injection on heat release in LTC. Our results show that water injection retards the start of combustion due to the latent heat of vaporization of the injected water. Furthermore, for start of water injection timings between 20 and 70 degrees before topmore » dead center, combustion is significantly elongated compared to without water injection. The 10–90% burn duration with 6.6 and 9.0 mg of water per cycle was 77% and 146% longer than without water injection, respectively. Forced thermal stratification result from a direct water injection which reduces the heat release rate by local evaporative cooling. Finally, the load limits with and without water injection were determined experimentally. Without water injection, the load range was 2.3–3.6 bar gross IMEP. By using water injection to control heat release, the load range in TSCI was 2.3–8.4 bar gross IMEP, which is a range expansion of over 350%. These results demonstrate that direct water injection can provide significant improvements to both controllability and the range of operability of LTC, thereby resolving the major challenges associated with HCCI.« less

  3. Dual-Mode Combustion

    NASA Technical Reports Server (NTRS)

    Goyne, Christopher P.; McDaniel, James C.

    2002-01-01

    The Department of Mechanical and Aerospace Engineering at the University of Virginia has conducted an investigation of the mixing and combustion processes in a hydrogen fueled dual-mode scramjet combustor. The experiment essentially consisted of the "direct connect" continuous operation of a Mach 2 rectangular combustor with a single unswept ramp fuel injector. The stagnation enthalpy of the test flow simulated a flight Mach number of 5. Measurements were obtained using conventional wall instrumentation and laser based diagnostics. These diagnostics included, pressure and wall temperature measurements, Fuel Plume Imaging (FPI) and Particle Image Velocimetry (PIV). A schematic of the combustor configuration and a summary of the measurements obtained are presented. The experimental work at UVa was parallel by Computational Fluid Dynamics (CFD) work at NASA Langley. The numerical and experiment results are compared in this document.

  4. Advanced Subsonic Combustion Rig

    NASA Technical Reports Server (NTRS)

    Lee, Chi-Ming

    1998-01-01

    Researchers from the NASA Lewis Research Center have obtained the first combustion/emissions data under extreme future engine operating conditions. In Lewis' new world-class 60-atm combustor research facility--the Advanced Subsonic Combustion Rig (ASCR)--a flametube was used to conduct combustion experiments in environments as extreme as 900 psia and 3400 F. The greatest challenge for combustion researchers is the uncertainty of the effects of pressure on the formation of nitrogen oxides (NOx). Consequently, U.S. engine manufacturers are using these data to guide their future combustor designs. The flametube's metal housing has an inside diameter of 12 in. and a length of 10.5 in. The flametube can be used with a variety of different flow paths. Each flow path is lined with a high-temperature, castable refractory material (alumina) to minimize heat loss. Upstream of the flametube is the injector section, which has an inside diameter of 13 in. and a length of 0.5-in. It was designed to provide for quick changeovers. This flametube is being used to provide all U.S. engine manufacturers early assessments of advanced combustion concepts at full power conditions prior to engine production. To date, seven concepts from engine manufacturers have been evaluated and improved. This collaborated development can potentially give U.S. engine manufacturers the competitive advantage of being first in the market with advanced low-emission technologies.

  5. Path planning during combustion mode switch

    SciTech Connect

    Jiang, Li; Ravi, Nikhil

    2015-12-29

    Systems and methods are provided for transitioning between a first combustion mode and a second combustion mode in an internal combustion engine. A current operating point of the engine is identified and a target operating point for the internal combustion engine in the second combustion mode is also determined. A predefined optimized transition operating point is selected from memory. While operating in the first combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion engine to approach the selected optimized transition operating point. When the engine is operating at the selected optimized transition operating point, the combustion mode is switched from the first combustion mode to the second combustion mode. While operating in the second combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion to approach the target operating point.

  6. Preliminary assessment of combustion modes for internal combustion wave rotors

    NASA Technical Reports Server (NTRS)

    Nalim, M. Razi

    1995-01-01

    Combustion within the channels of a wave rotor is examined as a means of obtaining pressure gain during heat addition in a gas turbine engine. Several modes of combustion are considered and the factors that determine the applicability of three modes are evaluated in detail; premixed autoignition/detonation, premixed deflagration, and non-premixed compression ignition. The last two will require strong turbulence for completion of combustion in a reasonable time in the wave rotor. The compression/autoignition modes will require inlet temperatures in excess of 1500 R for reliable ignition with most hydrocarbon fuels; otherwise, a supplementary ignition method must be provided. Examples of combustion mode selection are presented for two core engine applications that had been previously designed with equivalent 4-port wave rotor topping cycles using external combustion.

  7. Advanced Subsonic Combustion Rig Developed

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Advanced Subsonic Combustion Rig (ASCR), a unique, state-of-the-art facility for conducting combustion research, is located at the NASA Lewis Research Center in Cleveland, Ohio. The ASCR, which was nearing completion at the close of 1995, will be capable of simulating the very high pressure and high temperature conditions that are expected to exist in future, advanced subsonic gas turbine (jet) engines. Future environmental regulations will require much cleaner burning (more environmentally friendly) aircraft engines. The ASCR is critical to the development of these cleaner engines. It will allow NASA and U.S. aircraft engine industry researchers to identify and test promising clean-burning gas turbine engine combustion concepts under the pressure and temperature conditions that are expected for those future engines. Combustion processes will be investigated for a variety of next-generation aircraft engine sizes, including engines for large, long-range aircraft (with typical trip lengths of about 3000 mi) and for regional aircraft (with typical trip lengths of about 400 mi). The ASCR design was conceived and initiated in 1993, and fabrication and construction of the rig, including the buildup of an advanced control room, took place throughout 1994 and 1995. In early 1996, the ASCR will be operational for obtaining research data. The ASCR is an intricate part of the NASA Advanced Subsonic Technology Propulsion Program, which is aimed at developing technologies critical to the next generation of gas turbine engines. This effort is in collaboration with the U.S. aircraft gas turbine engine industry. A goal of the Advanced Subsonic Technology Propulsion Program is to develop combustion concepts and technologies that will result in gas turbine engines that produce 50 percent less nitrous oxide (NO_x) pollutants than current engines do. This facility is unique in its capability to simulate advanced subsonic engine pressure, temperature, and air flow rate conditions

  8. COSTS FOR ADVANCED COAL COMBUSTION TECHNOLOGIES

    EPA Science Inventory

    The report gives results of an evaluation of the development status of advanced coal combustion technologies and discusses the preparation of performance and economic models for their application to electric utility plants. he technologies addressed were atmospheric fluidized bed...

  9. Combustion synthesis of advanced composite materials

    NASA Technical Reports Server (NTRS)

    Moore, John J.

    1993-01-01

    Self-propagating high temperature (combustion) synthesis (SHS), has been investigated as a means of producing both dense and expanded (foamed) ceramic and ceramic-metal composites, ceramic powders and whiskers. Several model exothermic combustion synthesis reactions were used to establish the importance of certain reaction parameters, e.g., stoichiometry, green density, combustion mode, particle size, etc. on the control of the synthesis reaction, product morphology and properties. The use of an in situ liquid infiltration technique and the effect of varying the reactants and their stoichiometry to provide a range of reactant and product species i.e., solids, liquids and gases, with varying physical properties e.g., volatility and thermal conductivity, on the microstructure and morphology of synthesized composite materials is discussed. Conducting the combustion synthesis reaction in a reactive gas environment to take advantage of the synergistic effects of combustion synthesis and vapor phase transport is also examined.

  10. Annual Report: Advanced Combustion (30 September 2012)

    SciTech Connect

    Hawk, Jeffrey; Richards, George

    2012-09-30

    The Advanced Combustion Project addresses fundamental issues of fire-side and steam-side corrosion and materials performance in oxy-fuel combustion environments and provides an integrated approach into understanding the environmental and mechanical behavior such that environmental degradation can be ameliorated and long-term microstructural stability, and thus, mechanical performance can lead to longer lasting components and extended power plant life. The technical tasks of this effort are Oxy-combustion Environment Characterization, Alloy Modeling and Life Prediction, and Alloy Manufacturing and Process Development.

  11. Control Strategies for HCCI Mixed-Mode Combustion

    SciTech Connect

    Wagner, Robert M; Edwards, Kevin Dean

    2010-03-01

    Delphi Automotive Systems and ORNL established this CRADA to expand the operational range of Homogenous Charge Compression Ignition (HCCI) mixed-mode combustion for gasoline en-gines. ORNL has extensive experience in the analysis, interpretation, and control of dynamic engine phenomena, and Delphi has extensive knowledge and experience in powertrain compo-nents and subsystems. The partnership of these knowledge bases was important to address criti-cal barriers associated with the realistic implementation of HCCI and enabling clean, efficient operation for the next generation of transportation engines. The foundation of this CRADA was established through the analysis of spark-assisted HCCI data from a single-cylinder research engine. This data was used to (1) establish a conceptual kinetic model to better understand and predict the development of combustion instabilities, (2) develop a low-order model framework suitable for real-time controls, and (3) provide guidance in the initial definition of engine valve strategies for achieving HCCI operation. The next phase focused on the development of a new combustion metric for real-time characterization of the combustion process. Rapid feedback on the state of the combustion process is critical to high-speed decision making for predictive control. Simultaneous to the modeling/analysis studies, Delphi was focused on the development of engine hardware and the engine management system. This included custom Delphi hardware and control systems allowing for flexible control of the valvetrain sys-tem to enable HCCI operation. The final phase of this CRADA included the demonstration of conventional and spark assisted HCCI on the multi-cylinder engine as well as the characterization of combustion instabilities, which govern the operational boundaries of this mode of combustion. ORNL and Delphi maintained strong collaboration throughout this project. Meetings were held on a bi-weekly basis with additional reports, presentation, and

  12. Natural Gas for Advanced Dual-Fuel Combustion Strategies

    NASA Astrophysics Data System (ADS)

    Walker, Nicholas Ryan

    Natural gas fuels represent the next evolution of low-carbon energy feedstocks powering human activity worldwide. The internal combustion engine, the energy conversion device widely used by society for more than one century, is capable of utilizing advanced combustion strategies in pursuit of ultra-high efficiency and ultra-low emissions. Yet many emerging advanced combustion strategies depend upon traditional petroleum-based fuels for their operation. In this research the use of natural gas, namely methane, is applied to both conventional and advanced dual-fuel combustion strategies. In the first part of this work both computational and experimental studies are undertaken to examine the viability of utilizing methane as the premixed low reactivity fuel in reactivity controlled compression ignition, a leading advanced dual-fuel combustion strategy. As a result, methane is shown to be capable of significantly extending the load limits for dual-fuel reactivity controlled compression ignition in both light- and heavy-duty engines. In the second part of this work heavy-duty single-cylinder engine experiments are performed to research the performance of both conventional dual-fuel (diesel pilot ignition) and advanced dual-fuel (reactivity controlled compression ignition) combustion strategies using methane as the premixed low reactivity fuel. Both strategies are strongly influenced by equivalence ratio; diesel pilot ignition offers best performance at higher equivalence ratios and higher premixed methane ratios, whereas reactivity controlled compression ignition offers superior performance at lower equivalence ratios and lower premixed methane ratios. In the third part of this work experiments are performed in order to determine the dominant mode of heat release for both dual-fuel combustion strategies. By studying the dual-fuel homogeneous charge compression ignition and single-fuel spark ignition, strategies representative of autoignition and flame propagation

  13. Combustion mode switching with a turbocharged/supercharged engine

    DOEpatents

    Mond, Alan; Jiang, Li

    2015-09-22

    A method for switching between low- and high-dilution combustion modes in an internal combustion engine having an intake passage with an exhaust-driven turbocharger, a crankshaft-driven positive displacement supercharger downstream of the turbocharger and having variable boost controllable with a supercharger bypass valve, and a throttle valve downstream of the supercharger. The current combustion mode and mass air flow are determined. A switch to the target combustion mode is commanded when an operating condition falls within a range of predetermined operating conditions. A target mass air flow to achieve a target air-fuel ratio corresponding to the current operating condition and the target combustion mode is determined. The degree of opening of the supercharger bypass valve and the throttle valve are controlled to achieve the target mass air flow. The amount of residual exhaust gas is manipulated.

  14. Combustion modeling in advanced gas turbine systems

    SciTech Connect

    Smoot, L.D.; Hedman, P.O.; Fletcher, T.H.

    1995-10-01

    The goal of the U.S. Department of Energy`s Advanced Turbine Systems (ATS) program is to help develop and commercialize ultra-high efficiency, environmentally superior, and cost competitive gas turbine systems for base-load applications in the utility, independent power producer, and industrial markets. Combustion modeling, including emission characteristics, has been identified as a needed, high-priority technology by key professionals in the gas turbine industry.

  15. Advanced Combustion Modeling for Complex Turbulent Flows

    NASA Technical Reports Server (NTRS)

    Ham, Frank Stanford

    2005-01-01

    The next generation of aircraft engines will need to pass stricter efficiency and emission tests. NASA's Ultra-Efficient Engine Technology (UEET) program has set an ambitious goal of 70% reduction of NO(x) emissions and a 15% increase in fuel efficiency of aircraft engines. We will demonstrate the state-of-the-art combustion tools developed a t Stanford's Center for Turbulence Research (CTR) as part of this program. In the last decade, CTR has spear-headed a multi-physics-based combustion modeling program. Key technologies have been transferred to the aerospace industry and are currently being used for engine simulations. In this demo, we will showcase the next-generation combustion modeling tools that integrate a very high level of detailed physics into advanced flow simulation codes. Combustor flows involve multi-phase physics with liquid fuel jet breakup, evaporation, and eventual combustion. Individual components of the simulation are verified against complex test cases and show excellent agreement with experimental data.

  16. Advanced staged combustion system for power generation

    SciTech Connect

    Rehmat, A.; Goyal, A.

    1993-12-31

    To respond to the increasing market need for a new generation of plants with a substantial improvement in efficiency and a reduction in capital cost, the Institute of Gas Technology has developed an advanced staged, fluidized-bed combustion system concept. The staged fluidized-bed partial combustor produces the fuel gas at about 1500 F. The fuel gas, after particulate removal, is directed to a gas turbine followed by a steam cycle. Adequate sulfur capture and solids waste stabilization are attained by separating calcination, carbonization, and gasification/combustion steps in the staged fluidized beds. Intermediate gas cooling is avoided during the process to maximize the power production. The coal-to-electricity conversion efficiency of the system approaches 49 percent, which exceeds the efficiencies of the other emerging technologies.

  17. Ignition angle advancer for internal combustion engine

    SciTech Connect

    Yamazaki, T.

    1986-08-19

    This patent describes a throttle and spark advance control system for an internal combustion engine having a spark advance mechanism and a throttle valve comprising an operator controlled element, a throttle control lever supported for pivotal movement about an axis and directly connected to the operator controlled element for rotation under operator control. It also includes means for positively connecting the throttle control lever to the throttle valve for positioning the throttle valve in response to movement of the throttle control lever. A spark advance control lever supported for pivotal movement about an axis is included as well as motion transmitting means for operatively connecting the spark advance control lever to the throttle control lever for pivotal movement of the spark advance control lever about its axis in response to pivotal movement of the throttle control lever about its axis and the spark control lever to the spark advance mechanism for controlling the position of the spark advance mechanism in response to the position of the throttle control lever.

  18. Advanced Combustion and Emission Control Technical Team Roadmap

    SciTech Connect

    2013-06-01

    The Advanced Combustion and Emission Control (ACEC) Technical Team is focused on removing technical barriers to the commercialization of advanced, high-efficiency, emission-compliant internal combustion (IC) engines for light-duty vehicle powertrains (i.e., passenger car, minivan, SUV, and pickup trucks).

  19. FY2015 Advanced Combustion Engine Annual Progress Report

    SciTech Connect

    Singh, Gurpreet; Gravel, Roland M.; Howden, Kenneth C.; Breton, Leo

    2016-03-25

    The Advanced Combustion Engine research and development (R&D) subprogram within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to commercializing higher efficiency, very low emissions advanced internal combustion engines for passenger and commercial vehicles.

  20. FY2014 Advanced Combustion Engine Annual Progress Report

    SciTech Connect

    2015-03-01

    The Advanced Combustion Engine research and development (R&D) subprogram within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to commercializing higher efficiency, very low emissions advanced internal combustion engines for passenger and commercial vehicles.

  1. Longitudinal-Mode Combustion Instabilities: Modeling and Experiments

    NASA Technical Reports Server (NTRS)

    Cohen, J. M.; Hibshman, J. R.; Proscia, W.; Rosfjord, T. J.; Wake, B. E.; McVey, J. B.; Lovett, J.; Ondas, M.; DeLaat, J.; Breisacher, K.

    2000-01-01

    Combustion instabilities can lead to increased development time and cost for aeroengine gas turbines. This problem has been evident in the development of very-low emissions stationary gas turbines, and will likely be encountered in the newer, more aggressive aeroengine designs. In order to minimize development time and cost, it is imperative that potential combustion dynamics issues be resolved using analyses and smaller-scale experimentation. This paper discusses a methodology through which a problem in a full-scale engine was replicated in a single-nozzle laboratory combustor. Specifically, this approach is valid for longitudinal and "bulk" mode combustion instabilities. An explanation and partial validation of the acoustic analyses that were used to achieve this replication are also included. This approach yields a testbed for the diagnosis of combustion dynamics problems and for their solution through passive and active control techniques.

  2. Advanced Integrated Fuel/Combustion Systems

    DTIC Science & Technology

    2004-01-01

    This decrease will allow for increased combustion operating efficiencies and fuel economy with reduced emissions on both current and future aircraft...capability is planned to be implemented on the CFM-56 for future combustion studies. We made facility improvements to allow fuel composition studies...an Aero Gas Turbine Combustion Chamber," ASME 97-GT-148. 8. Tolpadi, A. K., Danis, A. M., Mongia , H. C., and Lindstedt R. P., "Soot Modeling in

  3. Advanced combustion turbines and cycles: An EPRI perspective

    SciTech Connect

    Touchton, G.; Cohn, A.

    1995-10-01

    EPRI conducts a broad program of research in combustion turbine technology on behalf of its funders which is directed toward improving their competitive positions through lower cost of generation and risk mitigation. The major areas of EPRI interest are: (1) Combustion Turbine Technology Development, Assessment, and Procurement Information and Products. (2) Risk mitigation of emerging combustion turbines through durability surveillance. (3) Existing Fleet Management and Improvement Technology. In the context of the DOE ATS Review, the present paper will address new advanced turbines and cycles and durability surveillance, of emerging combustion turbines. It will touch on existing fleet management and improvement technology as appropriate.

  4. Hydrodynamic model of advanced pressurized fluidized bed combustion

    SciTech Connect

    Horio, Masayuki; Lei, H.W.

    1997-12-31

    A hydrodynamic model was developed for the advanced pressurized fluidized bed combustion (A-PFBC) process. The particular system investigated here is composed of a pressurized circulating fluidized bed (PCFB) for coal gasification/desulfurization and a PCFB for combustion with the gas-solid counter-current flow through the two PCFBs. One of the most important parameters may be the material seal height (MSH) in the downcomer connecting the gasifier/desulfurizer and the combustor, which is thought to strongly influence the safe and stable operation of the process. In this mode, MSH was determined according to the pressure balance between the gasifier/desulfurizer and the combustor. The solid flux in the lower dense region of the two PCFBs was estimated by considering the clustering suspension and core-annulus flow. The mean cluster size and voidage in the cluster phase were predicted by the cluster size model of Horio-Ito (1996). Solid flux of the gasifier and combustor was calculated based on mass balances of limestone, char and ash in the system. Based on this model, the whole pressure profile loop in the system was predicted, and the effects of operating conditions on MSH between the gasifier and the combustor were investigated. The feasibility of the A-PCFB system with PCFBs both for the gasifier/desulfurizer and for the combustor was successfully confirmed.

  5. Advanced Combustion and Fuels; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    Zigler, Brad

    2015-06-08

    Presented at the U.S. Department of Energy Vehicle Technologies Office 2015 Annual Merit Review and Peer Evaluation Meeting, held June 8-12, 2015, in Arlington, Virginia. It addresses technical barriers of inadequate data and predictive tools for fuel and lubricant effects on advanced combustion engines, with the strategy being through collaboration, develop techniques, tools, and data to quantify critical fuel physico-chemical effects to enable development of advanced combustion engines that use alternative fuels.

  6. Nonlinear characteristics and detection of combustion modes for a hydrocarbon fueled scramjet

    NASA Astrophysics Data System (ADS)

    Zhang, Cong; Yang, Qingchun; Chang, Juntao; Tang, Jingfeng; Bao, Wen

    2015-05-01

    An experimental investigation of combustion mode transition in a hydrocarbon fueled scramjet combustor model is reported under Mach number 2.1 and 2.5 inflow conditions. Three different combustion modes with respect to equivalence ratio are observed, namely, scramjet mode, weak ramjet mode and strong ramjet mode. The typical features of different combustion modes are analyzed by wall-pressures and one-dimensionally estimated Mach number distributions. The processes of combustion mode transitions show significant nonlinear characteristics. The static pressure and Mach number have discontinuous sudden changes as the mode transition occurs, especially near the fuel-supply region, emphasizing the importance of detection and control of combustion modes. The nonlinear characteristics of wall-pressures near the exit of the isolator can be used in the detection of different combustion modes. A series of experiments prove that this pressure-magnitude-based detection technique is feasible.

  7. Testing a dual-mode ramjet engine with kerosene combustion

    NASA Astrophysics Data System (ADS)

    Levin, V. M.; Karasev, V. N.; Kartovitskii, L. L.; Krymov, E. A.; Skachkov, O. A.

    2015-09-01

    Results of life firing tests of a dual-mode ramjet engine intended for operation in the speed range M = 3-6 are discussed. The tests were carried out on a test bench under freestream conditions typical of Mach 6 flight at 27.6-km altitude. In the tests, the adopted design and technological solutions were verified, and efficient operation of the ramjet engine with kerosene combustion during 110 s was demonstrated.

  8. Combustion and Heat Transfer Studies Utilizing Advanced Diagnostics: Combustion Studies

    DTIC Science & Technology

    1992-11-01

    Appendices D, E, and F). The two main modeling approaches that enabled the calculation of stability from thermochemistry considera- tions are those of...Parallel TEACH -1Te Code Using an Approximately Implicit Algorithm." Proc. Tie prime authors of this report (G. Sturgess, D. Ballal S"ym Recem Advances and

  9. FY 2007 Progress Report for Advanced Combustion Engine Technologies

    SciTech Connect

    None, None

    2007-12-01

    Advanced combustion engines have great potential for achieving dramatic energy efficiency improvements in light-duty vehicle applications, where it is suited to both conventional and hybrid- electric powertrain configurations. Light-duty vehicles with advanced combustion engines can compete directly with gasoline engine hybrid vehicles in terms of fuel economy and consumer-friendly driving characteristics; also, they are projected to have energy efficiencies that are competitive with hydrogen fuel cell vehicles when used in hybrid applications.Advanced engine technologies being researched and developed by the Advanced Combustion Engine R&D Sub-Program will also allow the use of hydrogen as a fuel in ICEs and will provide an energy-efficient interim hydrogen-based powertrain technology during the transition to hydrogen/fuelcell-powered transportation vehicles.

  10. Renewable Energy Laboratory Development for Biofuels Advanced Combustion Studies

    SciTech Connect

    Soloiu, Valentin A.

    2012-03-31

    The research advanced fundamental science and applied engineering for increasing the efficiency of internal combustion engines and meeting emissions regulations with biofuels. The project developed a laboratory with new experiments and allowed investigation of new fuels and their combustion and emissions. This project supports a sustainable domestic biofuels and automotive industry creating economic opportunities across the nation, reducing the dependence on foreign oil, and enhancing U.S. energy security. The one year period of research developed fundamental knowledge and applied technology in advanced combustion, emissions and biofuels formulation to increase vehicle's efficiency. Biofuels combustion was investigated in a Compression Ignition Direct Injection (DI) to develop idling strategies with biofuels and an Indirect Diesel Injection (IDI) intended for auxiliary power unit.

  11. Advanced Fuels and Combustion Processes for Propulsion

    DTIC Science & Technology

    2010-09-01

    production from biomass steam reforming – Conduct a feasibility analysis of the proposed integrated process Energia Technologies - D. Nguyen & K. Parimi...strength foam material development by Ultramet – Combustion experiments performed U. Of Alabama – End-user input provided by Solar Turbines Major

  12. Chemical Kinetic Models for Advanced Engine Combustion

    SciTech Connect

    Pitz, William J.; Mehl, Marco; Westbrook, Charles K.

    2014-10-22

    The objectives for this project are as follows: Develop detailed chemical kinetic models for fuel components used in surrogate fuels for compression ignition (CI), homogeneous charge compression ignition (HCCI) and reactivity-controlled compression-ignition (RCCI) engines; and Combine component models into surrogate fuel models to represent real transportation fuels. Use them to model low-temperature combustion strategies in HCCI, RCCI, and CI engines that lead to low emissions and high efficiency.

  13. Evaluation of Advanced Bionics high resolution mode.

    PubMed

    Buechner, Andreas; Frohne-Buechner, Carolin; Gaertner, Lutz; Lesinski-Schiedat, Anke; Battmer, Rolf-Dieter; Lenarz, Thomas

    2006-07-01

    The objective of this paper is to evaluate the advantages of the Advanced Bionic high resolution mode for speech perception, through a retrospective analysis. Forty-five adult subjects were selected who had a minimum experience of three months' standard mode (mean of 10 months) before switching to high resolution mode. Speech perception was tested in standard mode immediately before fitting with high resolution mode, and again after a maximum of six months high resolution mode usage (mean of two months). A significant improvement was found, between 11 and 17%, depending on the test material. The standard mode preference does not give any indication about the improvement when switching to high resolution. Users who are converted within any study achieve a higher performance improvement than those converted in the clinical routine. This analysis proves the significant benefits of high resolution mode for users, and also indicates the need for guidelines for individual optimization of parameter settings in a high resolution mode program.

  14. Progress in Advanced Spray Combustion Code Integration

    NASA Technical Reports Server (NTRS)

    Liang, Pak-Yan

    1993-01-01

    A multiyear project to assemble a robust, muitiphase spray combustion code is now underway and gradually building up to full speed. The overall effort involves several university and government research teams as well as Rocketdyne. The first part of this paper will give an overview of the respective roles of the different participants involved, the master strategy, the evolutionary milestones, and an assessment of the state-of-the-art of various key components. The second half of this paper will highlight the progress made to date in extending the baseline Navier-Stokes solver to handle multiphase, multispecies, chemically reactive sub- to supersonic flows. The major hurdles to overcome in order to achieve significant speed ups are delineated and the approaches to overcoming them will be discussed.

  15. Combustion Synthesis of Advanced Porous Materials in Microgravity Environment

    NASA Technical Reports Server (NTRS)

    Zhang, X.; Moore, J. J.; Schowengerdt, F. D.; Johnson, D. P.

    1999-01-01

    Combustion synthesis, otherwise known as self-propagating high temperature synthesis (SHS), can be used to produce engineered advanced porous material implants which offer the possibility for bone ingrowth as well as a permanent structure framework for the long-term replacement of bone defects. The primary advantage of SHS is based on its rapid kinetics and favorable energetics. The structure and properties of materials produced by SHS are strongly dependent on the combustion reaction conditions. Combustion reaction conditions such as reaction stoichiometry, particle size, green density, the presence and use of diluents or inert reactants, and pre-heating of the reactants, will affect the exothermicity of the reaction. A number of conditions must be satisfied in order to obtain high porosity materials: an optimal amount of liquid, gas and solid phases must be present in the combustion front. Therefore, a balance among these phases at the combustion front must be created by the SHS reaction to successfully engineer a bone replacement material system. Microgravity testing has extended the ability to form porous products. The convective heat transfer mechanisms which operate in normal gravity, 1 g, constrain the combustion synthesis reactions. Gravity also acts to limit the porosity which may be formed as the force of gravity serves to restrict the gas expansion and the liquid movement during reaction. Infiltration of the porous product with other phases can modify both the extent of porosity and the mechanical properties.

  16. FY2013 Progress Report for Advanced Combustion Engine Research and Development

    SciTech Connect

    none,

    2013-12-01

    Annual progress report on the work of the the Advanced Combustion Engine Program. The Advanced Combustion Engine Program supports the Vehicle Technologies Office mission by addressing critical technical barriers to commercializing higher efficiency, very low emissions, advanced combustion engines for passenger and commercial vehicles that meet future federal emissions regulations.

  17. FY2012 Annual Progress Report for Advanced Combustion Engine Research and Development

    SciTech Connect

    none,

    2013-02-01

    Annual report on the work of the the Advanced Combustion Engine R&D subprogram. The Advanced Combustion Engine R&D subprogram supports the Vehicle Technologies Office mission by removing the critical technical barriers to commercialization of advanced internal combustion engines (ICEs) for passenger and commercial vehicles that meet future federal emissions regulations.

  18. Advanced Fuel Development and Fuel Combustion

    DTIC Science & Technology

    1997-08-01

    operation, and quality control monitoring requirements for these new elements. 39 TASK NO. 26: Surfactant Additives for Improved Low and High...increases are required. Aspen Systems has designed and synthesized a new class of multifunctional additives known as metal deactivating surfactants (MDS... Recycling 4 TASK NO. 03: Emissions Control Through Advanced Combustor Mixing Schemes 5 TASK NO. 04: Gas Layer Protection of Hot Carbon

  19. Advanced Diagnostics for High Pressure Spray Combustion.

    SciTech Connect

    Skeen, Scott A.; Manin, Julien Luc; Pickett, Lyle M.

    2014-06-01

    The development of accurate predictive engine simulations requires experimental data to both inform and validate the models, but very limited information is presently available about the chemical structure of high pressure spray flames under engine- relevant conditions. Probing such flames for chemical information using non- intrusive optical methods or intrusive sampling techniques, however, is challenging because of the physical and optical harshness of the environment. This work details two new diagnostics that have been developed and deployed to obtain quantitative species concentrations and soot volume fractions from a high-pressure combusting spray. A high-speed, high-pressure sampling system was developed to extract gaseous species (including soot precursor species) from within the flame for offline analysis by time-of-flight mass spectrometry. A high-speed multi-wavelength optical extinction diagnostic was also developed to quantify transient and quasi-steady soot processes. High-pressure sampling and offline characterization of gas-phase species formed following the pre-burn event was accomplished as well as characterization of gas-phase species present in the lift-off region of a high-pressure n-dodecane spray flame. For the initial samples discussed in this work several species were identified, including polycyclic aromatic hydrocarbons (PAH); however, quantitative mole fractions were not determined. Nevertheless, the diagnostic developed here does have this capability. Quantitative, time-resolved measurements of soot extinction were also accomplished and the novel use of multiple incident wavelengths proved valuable toward characterizing changes in soot optical properties within different regions of the spray flame.

  20. Advanced radiant combustion system. Final report, September 1989--September 1996

    SciTech Connect

    Sullivan, J.D.; Carswell, M.G.; Long, F.S.

    1996-09-01

    Results of the Advanced Radiant Combustion System (ARCS) project are presented in this report. This work was performed by Alzeta Corporation as prime contractor under a contract to the U.S. Department of Energy Office of Industrial Technologies as part of a larger DOE program entitled Research Program for Advanced Combustion Systems. The goals of the Alzeta ARCS project were to (a) Improve the high temperature performance characteristics of porous surface ceramic fiber burners, (b) Develop an Advanced Radiant Combustion System (ARCS) that combines combustion controls with an advanced radiant burner, and (c) Demonstrate the advanced burner and controls in an industrial application. Prior to the start of this project, Alzeta had developed and commercialized a porous surface radiant burner, the Pyrocore{trademark} burner. The product had been commercially available for approximately 5 years and had achieved commercial success in a number of applications ranging from small burners for commercial cooking equipment to large burners for low temperature industrial fluid heating applications. The burner was not recommended for use in applications with process temperatures above 1000{degrees}F, which prevented the burner from being used in intermediate to high temperature processes in the chemical and petroleum refining industries. The interest in increasing the maximum use temperature of the burner was motivated in part by a desire to expand the number of applications that could use the Pyrocore product, but also because many of the fluid sensitive heating applications of interest would benefit from the distributed flux characteristic of porous surface burners. Background information on porous surface radiant burners, and a discussion of advantages that would be provided by an improved product, are presented in Section 2.

  1. High-temperature corrosion in advanced combustion systems

    SciTech Connect

    Natesan, K.; Yanez-Herrero, M.; Fornasieri, C.

    1993-11-01

    Conceptual designs of advanced combustion systems that utilize coal as a feedstock require high temperature furnaces and heat transfer surfaces capable of operation at much elevated temperatures than those prevalent in current coal-fired power plants. The combination of elevated temperatures and hostile combustion environments necessitate development/application of advanced ceramic materials in these designs. The present paper characterizes the chemistry of coal-fired combustion environments over a wide temperature range of interest in these systems and discusses preliminary experimental results on several materials with potential for application in these systems. An experimental program has been initiated to evaluate materials for advanced combustion systems. Several candidate materials have been identified for evaluation. The candidates included advanced metallic alloys, monolithic ceramics, ceramic particulate/ceramic matrix composites, ceramic fiber/ceramic matrix composites, and ceramic whisker/ceramic matrix composites. The materials examined so far included nickel-base superalloys, alumina, stabilized zirconia, different types of silicon carbide, and silicon nitride. Coupon specimens of several of the materials have been tested in an air environment at 1000, 1200, and 1400{degree}C for 168 h. In addition, specimens were exposed to sodium-sulfate-containing salts at temperatures of 1000 and 1200{degree}C for 168 h. Extensive microstructural analyses were conducted on the exposed specimens to evaluate the corrosion performance of the materials for service in air and fireside environments of advanced coal-fired boilers. Additional tests are underway with several of the materials to evaluate their corrosion performance as a function of salt chemistry, alkali vapor concentration, gas chemistry, exposure temperature, and exposure time.

  2. Advanced Materials for Mercury 50 Gas Turbine Combustion System

    SciTech Connect

    Price, Jeffrey

    2008-09-30

    Solar Turbines Incorporated (Solar), under cooperative agreement number DE-FC26-0CH11049, has conducted development activities to improve the durability of the Mercury 50 combustion system to 30,000 hours life and reduced life cycle costs. This project is part of Advanced Materials in the Advanced Industrial Gas Turbines program in DOE's Office of Distributed Energy. The targeted development engine was the Mercury{trademark} 50 gas turbine, which was developed by Solar under the DOE Advanced Turbine Systems program (DOE contract number DE-FC21-95MC31173). As a generator set, the Mercury 50 is used for distributed power and combined heat and power generation and is designed to achieve 38.5% electrical efficiency, reduced cost of electricity, and single digit emissions. The original program goal was 20,000 hours life, however, this goal was increased to be consistent with Solar's standard 30,000 hour time before overhaul for production engines. Through changes to the combustor design to incorporate effusion cooling in the Generation 3 Mercury 50 engine, which resulted in a drop in the combustor wall temperature, the current standard thermal barrier coated liner was predicted to have 18,000 hours life. With the addition of the advanced materials technology being evaluated under this program, the combustor life is predicted to be over 30,000 hours. The ultimate goal of the program was to demonstrate a fully integrated Mercury 50 combustion system, modified with advanced materials technologies, at a host site for a minimum of 4,000 hours. Solar was the Prime Contractor on the program team, which includes participation of other gas turbine manufacturers, various advanced material and coating suppliers, nationally recognized test laboratories, and multiple industrial end-user field demonstration sites. The program focused on a dual path development route to define an optimum mix of technologies for the Mercury 50 and future gas turbine products. For liner and injector

  3. Longitudinal Mode Aeroengine Combustion Instability: Model and Experiment

    NASA Technical Reports Server (NTRS)

    Cohen, J. M.; Hibshman, J. R.; Proscia, W.; Rosfjord, T. J.; Wake, B. E.; McVey, J. B.; Lovett, J.; Ondas, M.; DeLaat, J.; Breisacher, K.

    2001-01-01

    Combustion instabilities in gas turbine engines are most frequently encountered during the late phases of engine development, at which point they are difficult and expensive to fix. The ability to replicate an engine-traceable combustion instability in a laboratory-scale experiment offers the opportunity to economically diagnose the problem more completely (to determine the root cause), and to investigate solutions to the problem, such as active control. The development and validation of active combustion instability control requires that the casual dynamic processes be reproduced in experimental test facilities which can be used as a test bed for control system evaluation. This paper discusses the process through which a laboratory-scale experiment and be designed to replicate an instability observed in a developmental engine. The scaling process used physically-based analyses to preserve the relevant geometric, acoustic, and thermo-fluid features, ensuring that results achieved in the single-nozzle experiment will be scalable to the engine.

  4. FY2011 Annual Progress Report for Advanced Combustion Engine Research and Development

    SciTech Connect

    none,

    2011-12-01

    Annual Progress Report for the Advanced Combustion Engine Research and Development (R&D) subprogram supporting the mission of the Vehicle Technologies Program by removing the critical technical barriers to commercialization of advanced internal combustion engines (ICEs) for passenger and commercial vehicles that meet future federal emissions regulations.

  5. Oxy-Combustion Environment Characterization: Fire- and Steam-Side Corrosion in Advanced Combustion

    SciTech Connect

    G. R. Holcomb; J. Tylczak; G. H. Meier; B. S. Lutz; N. M. Yanar; F. S. Pettit; J. Zhu; A. Wise; D. E. Laughlin; S. Sridhar

    2012-09-25

    Oxy-fuel combustion is burning a fuel in oxygen rather than air. The low nitrogen flue gas that results is relatively easy to capture CO{sub 2} from for reuse or sequestration. Corrosion issues associated with the environment change (replacement of much of the N{sub 2} with CO{sub 2} and higher sulfur levels) from air- to oxy-firing were examined. Alloys studied included model Fe-Cr alloys and commercial ferritic steels, austenitic steels, and nickel base superalloys. The corrosion behavior is described in terms of corrosion rates, scale morphologies, and scale/ash interactions for the different environmental conditions. Additionally, the progress towards laboratory oxidation tests in advanced ultra-supercritical steam is updated.

  6. Study of advanced rotary combustion engines for commuter aircraft

    NASA Technical Reports Server (NTRS)

    Berkowitz, M.; Jones, C.; Myers, D.

    1983-01-01

    Performance, weight, size, and maintenance data for advanced rotary aircraft engines suitable for comparative commuter aircraft system evaluation studies of alternate engine candidates are provided. These are turbocharged, turbocompounded, direct injected, stratified charge rotary engines. Hypothetical engines were defined (an RC4-74 at 895 kW and an RC6-87 at 1490 kW) based on the technologies and design approaches used in the highly advanced engine of a study of advanced general aviation rotary engines. The data covers the size range of shaft power from 597 kW (800 hp) to 1865 kW (2500 hp) and is in the form of drawings, tables, curves and written text. These include data on internal geometry and configuration, installation information, turbocharging and turbocompounding arrangements, design features and technologies, engine cooling, fuels, scaling for weight size BSFC and heat rejection for varying horsepower, engine operating and performance data, and TBO and maintenance requirements. The basic combustion system was developed and demonstrated; however the projected power densities and performance efficiencies require increases in engine internal pressures, thermal loading, and rotative speed.

  7. Advanced combustion technologies for gas turbine power plants

    SciTech Connect

    Vandsburger, U.; Desu, S.B.; Roe, L.A.

    1995-10-01

    During the second half of fiscal year 1995 progress was made in all three funded subject areas of the project as well as in a new area. Work in the area of mixing and combustion management through flow actuation was transferred into an enclosed facility. Jet mixing in a ducted co-flow was examined. The same jets were also subjected to a strong acoustic field established in the duct. Excitation of the jet with static spatial modes was shown to be effective even in the presence of co-flow and the acoustic field. Only when a wall is placed at the jet exit plane did the acoustic field dominate the jet dispersion (as expected due to reflective boundary conditions and the jet shear layer receptivity). This case is, however, not the most relevant to gas turbine combustors since it precludes co-flow. In the area of combustor testing, the design, fabrication, and assembly of a modular combustor test rig for project has been completed at the University of Arkansas. In the area of high temperature piezoceramic actuator materials development, Sr{sub 2}(Nb{sub x}Ta{sub 1-x}){sub 2}O{sub 7} powders have been synthesized, and bulk samples and thick films sintered. These materials have a curie temperature of about 1400{degrees}C compared with 300{degrees}C for the commercially available PZT. While at room temperature the new materials show a piezoelectric constant (d{sub 33}) which is a factor of 100 lower than PZT, at high temperatures they can exhibit significant action. A new area of non-linear, neural-net based, controllers for mixing and combustion control has been added during the second contract year. This work is not funded by the contract. Significant progress was made in this area. Neural nets with up to 15 neurons in the hidden layer were trained with experimental data and also with data generated using linear stability theory. System ID was performed successfully. The network was then used to predict the behavior of jets excited at other modes not used for the training.

  8. FY2009 Annual Progress Report for Advanced Combustion Engine Research and Development

    SciTech Connect

    none,

    2009-12-01

    Fiscal Year 2009 Annual Progress Report for the Advanced Combustion Engine Research and Development (R&D) subprogram. The Advanced Combustion Engine R&D subprogram supports the mission of the VTP program by removing the critical technical barriers to commercialization of advanced internal combustion engines (ICEs) for passenger and commercial vehicles that meet future Federal emissions regulations. Dramatically improving the efficiency of ICEs and enabling their introduction in conventional as well as hybrid electric vehicles is the most promising and cost-effective approach to increasing vehicle fuel economy over the next 30 years.

  9. Combustion and Magnetohydrodynamic Processes in Advanced Pulse Detonation Rocket Engines

    NASA Astrophysics Data System (ADS)

    Cole, Lord Kahil

    A number of promising alternative rocket propulsion concepts have been developed over the past two decades that take advantage of unsteady combustion waves in order to produce thrust. These concepts include the Pulse Detonation Rocket Engine (PDRE), in which repetitive ignition, propagation, and reflection of detonations and shocks can create a high pressure chamber from which gases may be exhausted in a controlled manner. The Pulse Detonation Rocket Induced Magnetohydrodynamic Ejector (PDRIME) is a modification of the basic PDRE concept, developed by Cambier (1998), which has the potential for performance improvements based on magnetohydrodynamic (MHD) thrust augmentation. The PDRIME has the advantage of both low combustion chamber seeding pressure, per the PDRE concept, and efficient energy distribution in the system, per the rocket-induced MHD ejector (RIME) concept of Cole, et al. (1995). In the initial part of this thesis, we explore flow and performance characteristics of different configurations of the PDRIME, assuming quasi-one-dimensional transient flow and global representations of the effects of MHD phenomena on the gas dynamics. By utilizing high-order accurate solvers, we thus are able to investigate the fundamental physical processes associated with the PDRIME and PDRE concepts and identify potentially promising operating regimes. In the second part of this investigation, the detailed coupling of detonations and electric and magnetic fields are explored. First, a one-dimensional spark-ignited detonation with complex reaction kinetics is fully evaluated and the mechanisms for the different instabilities are analyzed. It is found that complex kinetics in addition to sufficient spatial resolution are required to be able to quantify high frequency as well as low frequency detonation instability modes. Armed with this quantitative understanding, we then examine the interaction of a propagating detonation and the applied MHD, both in one-dimensional and two

  10. Application of advanced laser diagnostics to hypersonic wind tunnels and combustion systems.

    SciTech Connect

    North, Simon W.; Hsu, Andrea G.; Frank, Jonathan H.

    2009-09-01

    This LDRD was a Sandia Fellowship that supported Andrea Hsu's PhD research at Texas A&M University and her work as a visitor at Sandia's Combustion Research Facility. The research project at Texas A&M University is concerned with the experimental characterization of hypersonic (Mach>5) flowfields using experimental diagnostics. This effort is part of a Multidisciplinary University Research Initiative (MURI) and is a collaboration between the Chemistry and Aerospace Engineering departments. Hypersonic flight conditions often lead to a non-thermochemical equilibrium (NTE) state of air, where the timescale of reaching a single (equilibrium) Boltzmann temperature is much longer than the timescale of the flow. Certain molecular modes, such as vibrational modes, may be much more excited than the translational or rotational modes of the molecule, leading to thermal-nonequilibrium. A nontrivial amount of energy is therefore contained within the vibrational mode, and this energy cascades into the flow as thermal energy, affecting flow properties through vibrational-vibrational (V-V) and vibrational-translational (V-T) energy exchanges between the flow species. The research is a fundamental experimental study of these NTE systems and involves the application of advanced laser and optical diagnostics towards hypersonic flowfields. The research is broken down into two main categories: the application and adaptation of existing laser and optical techniques towards characterization of NTE, and the development of new molecular tagging velocimetry techniques which have been demonstrated in an underexpanded jet flowfield, but may be extended towards a variety of flowfields. In addition, Andrea's work at Sandia National Labs involved the application of advanced laser diagnostics to flames and turbulent non-reacting jets. These studies included quench-free planar laser-induced fluorescence measurements of nitric oxide (NO) and mixture fraction measurements via Rayleigh scattering.

  11. FY2010 Annual Progress Report for Advanced Combustion Engine Research and Development

    SciTech Connect

    Singh, Gurpreet

    2010-12-01

    The Advanced Combustion Engine R&D subprogram supports the mission of the Vehicle Technologies Program by removing the critical technical barriers to commercialization of advanced internal combustion engines (ICEs) for passenger and commercial vehicles that meet future Federal emissions regulations. Dramatically improving the efficiency of ICEs and enabling their introduction in conventional as well as hybrid electric vehicles is the most promising and cost-effective approach to increasing vehicle fuel economy over the next 30 years.

  12. Resonant mode interactions and the bifurcation of combustion-driven acoustic oscillations in resonance tubes

    SciTech Connect

    Margolis, S.B. . Combustion Research Facility)

    1994-12-01

    Acoustic oscillations in practical combustion devices such as pulse combustors and rocket motors, whether desirable or not, are properly interpreted as combustion instabilities. A nonlinear stability analysis of the corresponding fluid motions than shows that the nonsteady behavior is governed by infinitely coupled systems of nonlinear evolution equations for the amplitudes of the classical acoustic modes. However, under certain conditions, it has been conjectured that relatively low-order truncations can give qualitatively correct physical results. In the present work, one particular model of a pulse combustor is considered, and a parameter regime in the neighborhood of a primary acoustic bifurcation where either one or a pair of purely longitudinal acoustic modes achieves a positive linear growth rate is focused upon. In the first case, it is formally shown that a decoupling occurs such that a two-mode approximation consisting of the linearly unstable mode and its first resonant harmonic completely determines the dynamics of the oscillation. In the later case, it is again demonstrated that a decoupling occurs, and although mode interactions require the retention of additional modes besides the two linearly unstable modes and their first resonant harmonics, a relatively low-order dynamical system still governs the bifurcation behavior. The presence of two linearly unstable modes is then shown to lead to more complicated dynamics, including the stable secondary bifurcation of a multiperiodic acoustic oscillation from one of the single-period primary branches.

  13. Method and device for diagnosing and controlling combustion instabilities in internal combustion engines operating in or transitioning to homogeneous charge combustion ignition mode

    DOEpatents

    Wagner, Robert M [Knoxville, TN; Daw, Charles S [Knoxville, TN; Green, Johney B [Knoxville, TN; Edwards, Kevin D [Knoxville, TN

    2008-10-07

    This invention is a method of achieving stable, optimal mixtures of HCCI and SI in practical gasoline internal combustion engines comprising the steps of: characterizing the combustion process based on combustion process measurements, determining the ratio of conventional and HCCI combustion, determining the trajectory (sequence) of states for consecutive combustion processes, and determining subsequent combustion process modifications using said information to steer the engine combustion toward desired behavior.

  14. Applications of a single-longitudinal-mode alexandrite laser for diagnostics of parameters of combustion interest

    NASA Astrophysics Data System (ADS)

    Li, Z. S.; Afzelius, M.; Zetterberg, J.; Aldén, M.

    2004-10-01

    We report on the applications of a single-longitudinal-mode (SLM) pulsed alexandrite laser system for diagnostics of parameters of flow/combustion interest. The laser system is characterized by its narrow linewidth, high peak power, and broad tunablity. The absolute frequency of the laser output was monitored by a wavelength diagnostic system, which included a high-resolution confocal etalon and a molecular iodine laser-induced fluorescence (LIF) detection system. Different nonlinear frequency conversion schemes were used to cover a large frequency range from the infrared to the deep UV. The versatility of the laser system for flow/combustion diagnostics is demonstrated in three applications, namely filtered Rayleigh scattering, high-resolution Doppler-free two-photon LIF of CO, and infrared LIF and polarization spectroscopy of CO2. The potential impacts of using this SLM laser system in laser flow/combustion diagnostic applications are discussed.

  15. Advanced Combustion Systems for Next Generation Gas Turbines

    SciTech Connect

    Joel Haynes; Jonathan Janssen; Craig Russell; Marcus Huffman

    2006-01-01

    Next generation turbine power plants will require high efficiency gas turbines with higher pressure ratios and turbine inlet temperatures than currently available. These increases in gas turbine cycle conditions will tend to increase NOx emissions. As the desire for higher efficiency drives pressure ratios and turbine inlet temperatures ever higher, gas turbines equipped with both lean premixed combustors and selective catalytic reduction after treatment eventually will be unable to meet the new emission goals of sub-3 ppm NOx. New gas turbine combustors are needed with lower emissions than the current state-of-the-art lean premixed combustors. In this program an advanced combustion system for the next generation of gas turbines is being developed with the goal of reducing combustor NOx emissions by 50% below the state-of-the-art. Dry Low NOx (DLN) technology is the current leader in NOx emission technology, guaranteeing 9 ppm NOx emissions for heavy duty F class gas turbines. This development program is directed at exploring advanced concepts which hold promise for meeting the low emissions targets. The trapped vortex combustor is an advanced concept in combustor design. It has been studied widely for aircraft engine applications because it has demonstrated the ability to maintain a stable flame over a wide range of fuel flow rates. Additionally, it has shown significantly lower NOx emission than a typical aircraft engine combustor and with low CO at the same time. The rapid CO burnout and low NOx production of this combustor made it a strong candidate for investigation. Incremental improvements to the DLN technology have not brought the dramatic improvements that are targeted in this program. A revolutionary combustor design is being explored because it captures many of the critical features needed to significantly reduce emissions. Experimental measurements of the combustor performance at atmospheric conditions were completed in the first phase of the program

  16. Recent Advances In Science Support For Isolated Droplet Combustion Experiments

    NASA Technical Reports Server (NTRS)

    Dryer, F. L.; Kazakov, A.; Urban, B. D.; Kroenlein, K.

    2003-01-01

    In a joint program involving Prof. F.A. Williams of the University of California, San Diego and Dr. V. Nayagam of the National Center for Microgravity Research, the combustion characteristics of isolated liquid fuel droplets of n-heptane, n-decane, methanol, methanol-water, ethanol and ethanol-water having initial diameters between about 1 mm and 6 mm continues to be investigated. The objectives of the work are to improve fundamental knowledge of droplet combustion dynamics for pure fuels and fuel-water mixtures through microgravity experiments and theoretical analyses. The Princeton contributions support the engineering design, data analysis, and data interpretation requirements for the study of initially single component, spherically symmetric, isolated droplet combustion studies through experiments and numerical modeling. UCSD contributions are described in a companion communication in this conference. The Princeton effort also addresses the analyses of Fiber Supported Droplet Combustion (FSDC) experiments conducted with the above fuels and collaborative work with others who are investigating droplet combustion in the presence of steady convection. A thorough interpretation of droplet burning behavior for n-heptane and n-decane over a relatively wide range of conditions also involves the influences of sooting on the combustion behavior, and this particular aspect on isolated burning of droplets is under consideration in a collaborative program underway with Drexel University. This collaboration is addressed in another communication at this conference. The one-dimensional, time-dependent, numerical modeling approach that we have continued to evolve for analyzing isolated, quiescent droplet combustion data has been further applied to investigate several facets of isolated droplet burning of simple alcohols, n-heptane, and n-decane. Some of the new results are described below.

  17. Mixed-Source EGR for Enabling High Efficiency Clean Combustion Modes in a Light-Duty Diesel Engine

    SciTech Connect

    Cho, Kukwon; Han, Manbae; Wagner, Robert M; Sluder, Scott

    2008-01-01

    The source of exhaust gas recirculation (EGR), and consequently composition and temperature, has a significant effect on advanced combustion modes including stability, efficiency, and emissions. The effects of high-pressure loop EGR (HPL EGR) and low-pressure loop EGR (LPL EGR) on achieving high efficiency clean combustion (HECC) modes in a light-duty diesel engine were characterized in this study. High dilution operation is complicated in real-world situations due to inadequate control of mixture temperature and the slow response of LPL EGR systems. Mixed-source EGR (combination of HPL EGR and LPL EGR) was investigated as a reasonable approach for controlling mixture temperature. The potential of mixed-source EGR has been explored using LPL EGR as a 'base' for dilution rather than as a sole source. HPL EGR provides the 'trim' for controlling mixture temperature and has the potential for enabling precise control of dilution targets. This approach also has a benefit where LPL EGR does not provide sufficient dilution for achieving conditions appropriate for HECC operation. The balance of the required dilution could be achieved with HPL EGR mitigating the need for throttling or a LPL EGR pump. The results of this investigation revealed significant differences in engine-out emissions and performance for various EGR sources.

  18. Baseline Computational Fluid Dynamics Methodology for Longitudinal-Mode Liquid-Propellant Rocket Combustion Instability

    NASA Technical Reports Server (NTRS)

    Litchford, R. J.

    2005-01-01

    A computational method for the analysis of longitudinal-mode liquid rocket combustion instability has been developed based on the unsteady, quasi-one-dimensional Euler equations where the combustion process source terms were introduced through the incorporation of a two-zone, linearized representation: (1) A two-parameter collapsed combustion zone at the injector face, and (2) a two-parameter distributed combustion zone based on a Lagrangian treatment of the propellant spray. The unsteady Euler equations in inhomogeneous form retain full hyperbolicity and are integrated implicitly in time using second-order, high-resolution, characteristic-based, flux-differencing spatial discretization with Roe-averaging of the Jacobian matrix. This method was initially validated against an analytical solution for nonreacting, isentropic duct acoustics with specified admittances at the inflow and outflow boundaries. For small amplitude perturbations, numerical predictions for the amplification coefficient and oscillation period were found to compare favorably with predictions from linearized small-disturbance theory as long as the grid exceeded a critical density (100 nodes/wavelength). The numerical methodology was then exercised on a generic combustor configuration using both collapsed and distributed combustion zone models with a short nozzle admittance approximation for the outflow boundary. In these cases, the response parameters were varied to determine stability limits defining resonant coupling onset.

  19. Dual-Mode Combustion of Hydrogen in a Mach 5, Continuous-Flow Facility

    NASA Technical Reports Server (NTRS)

    Goyne, C. P.; McDaniel, J. C.; Quagliaroli, T. M.; Krauss, R. H.; Day, S. W.; Reubush, D. E. (Technical Monitor); McClinton, C. R. (Technical Monitor); Reubush, D. E.

    2001-01-01

    Results of an experimental and numerical study of a dual-mode scramjet combustor are reported. The experiment consisted of a direct-connect test of a Mach 2 hydrogen-air combustor with a single unswept-ramp fuel injector. The flow stagnation enthalpy simulated a flight Mach number of 5. Measurements were obtained using conventional wall instrumentation and a particle-imaging laser diagnostic technique. The particle imaging was enabled through the development of a new apparatus for seeding fine silicon dioxide particles into the combustor fuel stream. Numerical simulations of the combustor were performed using the GASP code. The modeling, and much of the experimental work, focused on the supersonic combustion mode. Reasonable agreement was observed between experimental and numerical wall pressure distributions. However, the numerical model was unable to predict accurately the effects of combustion on the fuel plume size, penetration, shape, and axial growth.

  20. Progress in analytical methods to predict and control azimuthal combustion instability modes in annular chambers

    NASA Astrophysics Data System (ADS)

    Bauerheim, M.; Nicoud, F.; Poinsot, T.

    2016-02-01

    Longitudinal low-frequency thermoacoustic unstable modes in combustion chambers have been intensively studied experimentally, numerically, and theoretically, leading to significant progress in both understanding and controlling these acoustic modes. However, modern annular gas turbines may also exhibit azimuthal modes, which are much less studied and feature specific mode structures and dynamic behaviors, leading to more complex situations. Moreover, dealing with 10-20 burners mounted in the same chamber limits the use of high fidelity simulations or annular experiments to investigate these modes because of their complexity and costs. Consequently, for such circumferential acoustic modes, theoretical tools have been developed to uncover underlying phenomena controlling their stability, nature, and dynamics. This review presents recent progress in this field. First, Galerkin and network models are described with their pros and cons in both the temporal and frequency framework. Then, key features of such acoustic modes are unveiled, focusing on their specificities such as symmetry breaking, non-linear modal coupling, forcing by turbulence. Finally, recent works on uncertainty quantifications, guided by theoretical studies and applied to annular combustors, are presented. The objective is to provide a global view of theoretical research on azimuthal modes to highlight their complexities and potential.

  1. Gasoline Ultra Efficient Fuel Vehicle with Advanced Low Temperature Combustion

    SciTech Connect

    Confer, Keith

    2014-12-18

    The objective of this program was to develop, implement and demonstrate fuel consumption reduction technologies which are focused on reduction of friction and parasitic losses and on the improvement of thermal efficiency from in-cylinder combustion. The program was executed in two phases. The conclusion of each phase was marked by an on-vehicle technology demonstration. Phase I concentrated on short term goals to achieve technologies to reduce friction and parasitic losses. The duration of Phase I was approximately two years and the target fuel economy improvement over the baseline was 20% for the Phase I demonstration. Phase II was focused on the development and demonstration of a breakthrough low temperature combustion process called Gasoline Direct- Injection Compression Ignition (GDCI). The duration of Phase II was approximately four years and the targeted fuel economy improvement was 35% over the baseline for the Phase II demonstration vehicle. The targeted tailpipe emissions for this demonstration were Tier 2 Bin 2 emissions standards.

  2. Preliminary tests of an advanced high-temperature combustion system

    NASA Technical Reports Server (NTRS)

    Wear, J. D.; Trout, A. M.; Smith, J. M.; Jacobs, R. E.

    1983-01-01

    A combustion system has been developed to operate efficiently and with good durability at inlet pressures to 4.05 MPa (40 atm), inlet air temperatures to 900 K, and exhaust gas temperatures to 2480 K. A preliminary investigation of this system was conducted at inlet pressures to 0.94 MPa (9 atm), a nominal inlet air temperature of 560 K, and exhaust gas temperatures to 2135 K. A maximum combustion efficiency of 98.5 percent was attained at a fuel-air ratio of 0.033; the combustion efficiency decreased to about 90 percent as the fuel-air ratio was increased to 0.058. An average liner metal temperature of 915 K, 355 kelvins greater than the nominal inlet air temperature, was reached with an average exhaust gas temperature of 2090 K. The maximum local metal temperature at this condition was about 565 kelvins above the nominal inlet air temperature and decreased to 505 kelvins above with increasing combustor pressure. Tests to determine the isothermal total pressure loss of the combustor showed a liner loss of 1.1 percent and a system loss of 6.5 percent.

  3. Instrumentation advances in emissions characterization from propellant/explosive combustion

    SciTech Connect

    Einfeld, W.; Morrison, D.J.; Mullins, S.E.

    1995-12-31

    Results from a chamber study to characterize emissions from combustion of selected pure energetic materials are presented in this paper. The study was carried out as a part of a comprehensive air pathways risk assessment for a propellant and explosive manufacturing facility that engages in open burning methods for manufacturing waste disposal. Materials selected for emissions characterization in this study included both aluminized and non-aluminized composite propellant, a double base propellant and a plastic bonded explosive. Combustion tests in a specialized chamber revealed very low emissions for gaseous products of incomplete combustion such as carbon monoxide and nitrogen oxides. Analysis of gaseous and aerosol emission products for a pre-selected target analyte list that included both volatile and semi-volatile organics revealed either low or non-detectable emissions for the four energetic types tested. Hydrogen chloride was detected as a major emission product from propellants containing ammonium perchlorate. Results from this work reveal that about one-half of the chlorine in the original material is released as hydrogen chloride. Based on earlier work, the balance of the chlorine emissions is expected to be in the form of chlorine gas.

  4. Experimental Investigation of Fuel-Reactivity Controlled Compression Ignition (RCCI) Combustion Mode in a Multi-Cylinder, Light-Duty Diesel Engine

    SciTech Connect

    Cho, Kukwon; Curran, Scott; Prikhodko, Vitaly Y; Sluder, Scott; Parks, II, James E; Wagner, Robert M

    2011-01-01

    An experimental study was performed to provide the combustion and emission characteristics resulting from fuel-reactivity controlled compression ignition (RCCI) combustion mode utilizing dual-fuel approach in a light-duty, multi-cylinder diesel engine. In-cylinder fuel blending using port fuel injection of gasoline before intake valve opening (IVO) and early-cycle, direct injection of diesel fuel was used as the charge preparation and fuel blending strategy. In order to achieve the desired auto-ignition quality through the stratification of the fuel-air equivalence ratio ( ), blends of commercially available gasoline and diesel fuel were used. Engine experiments were performed at an engine speed of 2300rpm and an engine load of 4.3bar brake mean effective pressure (BMEP). It was found that significant reduction in both nitrogen oxide (NOx) and particulate matter (PM) was realized successfully through the RCCI combustion mode even without applying exhaust gas recirculation (EGR). However, high carbon monoxide (CO) and hydrocarbon (HC) emissions were observed. The low combustion gas temperature during the expansion and exhaust processes seemed to be the dominant source of high CO emissions in the RCCI combustion mode. The high HC emissions during the RCCI combustion mode could be due to the increased combustion quenching layer thickness as well as the -stratification at the periphery of the combustion chamber. The slightly higher brake thermal efficiency (BTE) of the RCCI combustion mode was observed than the other combustion modes, such as the conventional diesel combustion (CDC) mode, and single-fuel, premixed charge compression ignition (PCCI) combustion mode. The parametric study of the RCCI combustion mode revealed that the combustion phasing and/or the peak cylinder pressure rise rate of the RCCI combustion mode could be controlled by several physical parameters premixed ratio (rp), intake swirl intensity, and start of injection (SOI) timing of directly

  5. Advanced combustion techniques for controlling NO sub x emissions of high altitude cruise aircraft

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Reck, G. M.

    1976-01-01

    An array of experiments designed to explore the potential of advanced combustion techniques for controlling the emissions of aircraft into the upper atmosphere was discussed. Of particular concern are the oxides of nitrogen (NOx) emissions into the stratosphere. The experiments utilize a wide variety of approaches varying from advanced combustor concepts to fundamental flame tube experiments. Results are presented which indicate that substantial reductions in cruise NOx emissions should be achievable in future aircraft engines. A major NASA program is described which focuses the many fundamental experiments into a planned evolution and demonstration of the prevaporized-premixed combustion technique in a full-scale engine.

  6. DOE Project: Optimization of Advanced Diesel Engine Combustion Strategies "University Research in Advanced Combustion and Emissions Control" Office of FreedomCAR and Vehicle Technologies Program

    SciTech Connect

    Reitz, Rolf; Foster, D.; Ghandhi, J.; Rothamer, D.; Rutland, C.; Sanders, S.; Trujillo, M.

    2012-10-26

    The goal of the present technology development was to increase the efficiency of internal combustion engines while minimizing the energy penalty of meeting emissions regulations. This objective was achieved through experimentation and the development of advanced combustion regimes and emission control strategies, coupled with advanced petroleum and non-petroleum fuel formulations. To meet the goals of the project, it was necessary to improve the efficiency of expansion work extraction, and this required optimized combustion phasing and minimized in-cylinder heat transfer losses. To minimize fuel used for diesel particulate filter (DPF) regeneration, soot emissions were also minimized. Because of the complex nature of optimizing production engines for real-world variations in fuels, temperatures and pressures, the project applied high-fidelity computing and high-resolution engine experiments synergistically to create and apply advanced tools (i.e., fast, accurate predictive models) developed for low-emission, fuel-efficient engine designs. The companion experiments were conducted using representative single- and multi-cylinder automotive and truck diesel engines.

  7. Analyses of Longitudinal Mode Combustion Instability in J-2X Gas Generator Development

    NASA Technical Reports Server (NTRS)

    Hulka, J. R.; Protz, C. S.; Casiano, M. J.; Kenny, R. J.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) and Pratt & Whitney Rocketdyne are developing a liquid oxygen/liquid hydrogen rocket engine for future upper stage and trans-lunar applications. This engine, designated the J-2X, is a higher pressure, higher thrust variant of the Apollo-era J-2 engine. The contract for development was let to Pratt & Whitney Rocketdyne in 2006. Over the past several years, development of the gas generator for the J-2X engine has progressed through a variety of workhorse injector, chamber, and feed system configurations on the component test stand at the NASA Marshall Space Flight Center (MSFC). Several of the initial configurations resulted in combustion instability of the workhorse gas generator assembly at a frequency near the first longitudinal mode of the combustion chamber. In this paper, several aspects of these combustion instabilities are discussed, including injector, combustion chamber, feed system, and nozzle influences. To ensure elimination of the instabilities at the engine level, and to understand the stability margin, the gas generator system has been modeled at the NASA MSFC with two techniques, the Rocket Combustor Interaction Design and Analysis (ROCCID) code and a lumped-parameter MATLAB(TradeMark) model created as an alternative calculation to the ROCCID methodology. To correctly predict the instability characteristics of all the chamber and injector geometries and test conditions as a whole, several inputs to the submodels in ROCCID and the MATLAB(TradeMark) model were modified. Extensive sensitivity calculations were conducted to determine how to model and anchor a lumped-parameter injector response, and finite-element and acoustic analyses were conducted on several complicated combustion chamber geometries to determine how to model and anchor the chamber response. These modifications and their ramification for future stability analyses of this type are discussed.

  8. Advanced combustion technologies for gas turbine power plants

    SciTech Connect

    Vandsburger, U.; Roe, L.A.; Desu, S.B.

    1995-12-31

    Objectives are to develop actuators for enhancing the mixing between gas streams, increase combustion stability, and develop hgih-temperature materials for actuators and sensors in combustors. Turbulent kinetic energy maps of an excited jet with co-flow in a cavity with a partially closed exhaust end are given with and without a longitudinal or a transverse acoustic field. Dielectric constants and piezoelectric coefficients were determined for Sr{sub 2}(Nb{sub x}Ta{sub 1-x}){sub 2}O{sub 7} ceramics.

  9. The Effects of Gravity on Combustion and Structure Formation During Synthesis of Advanced Materials

    NASA Technical Reports Server (NTRS)

    Varma, A.; Pelekh, A.; Mukasyan, A.

    1999-01-01

    Combustion in a variety of heterogeneous systems, leading to the synthesis of advanced materials, is characterized by high temperatures (2000-3500 K) and heating rates (up to 10(exp 6) K/s) at and ahead of the reaction front. These high temperatures generate liquids and gases which are subject to gravity-driven flow. The removal of such gravitational effects is likely to provide increased control of the reaction front, with a consequent improvement in control of the microstructure of the synthesized products. Thus, microgravity experiments can lead to major advances in the understanding of fundamental aspects of combustion and structure formation under the extreme conditions of the combustion synthesis wave. In addition, the specific features of microgravity environment allow one to produce unique materials, which cannot be obtained under terrestrial conditions. The general goals of the current research are: 1) to improve the understanding of fundamental phenomena taking place during combustion of heterogeneous systems, 2) to use low-gravity experiments for insight into the physics and chemistry of materials synthesis processes, and 3) based on the obtained knowledge, to optimize processing conditions for synthesis of advanced materials with desired microstructures and properties. This research follows logically from the results of investigations we have conducted in the framework of our previous grant on gravity influence on combustion synthesis (CS) of gasless systems. Prior work, by others and by us, has clearly demonstrated that gravity plays an important role during combustion synthesis of materials. The immediate tasks for the future are to quantitatively identify the nature of observed effects, and to create accurate local kinetic models of the processes, which can lead to a control of the microstructure and properties of the synthesized materials. In summary, this is the value of the proposed research. Based on our prior work, we focus on the fundamental

  10. Laboratory Demonstrations for PDE and Metals Combustion at NASA MSFC's Advanced Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Report provides status reporting on activities under order no. H-30549 for the period December 1 through December 31, 1999. Details the activities of the contract in the coordination of planned conduct of experiments at the MSFC Advanced Propulsion Laboratory in pulse detonation MHD power production and metals combustion.

  11. Development of Kinetic Mechanisms for Next-Generation Fuels and CFD Simulation of Advanced Combustion Engines

    SciTech Connect

    Pitz, William J.; McNenly, Matt J.; Whitesides, Russell; Mehl, Marco; Killingsworth, Nick J.; Westbrook, Charles K.

    2015-12-17

    Predictive chemical kinetic models are needed to represent next-generation fuel components and their mixtures with conventional gasoline and diesel fuels. These kinetic models will allow the prediction of the effect of alternative fuel blends in CFD simulations of advanced spark-ignition and compression-ignition engines. Enabled by kinetic models, CFD simulations can be used to optimize fuel formulations for advanced combustion engines so that maximum engine efficiency, fossil fuel displacement goals, and low pollutant emission goals can be achieved.

  12. Numerical modeling of spray combustion with an advanced VOF method

    NASA Technical Reports Server (NTRS)

    Chen, Yen-Sen; Shang, Huan-Min; Shih, Ming-Hsin; Liaw, Paul

    1995-01-01

    This paper summarizes the technical development and validation of a multiphase computational fluid dynamics (CFD) numerical method using the volume-of-fluid (VOF) model and a Lagrangian tracking model which can be employed to analyze general multiphase flow problems with free surface mechanism. The gas-liquid interface mass, momentum and energy conservation relationships are modeled by continuum surface mechanisms. A new solution method is developed such that the present VOF model can be applied for all-speed flow regimes. The objectives of the present study are to develop and verify the fractional volume-of-fluid cell partitioning approach into a predictor-corrector algorithm and to demonstrate the effectiveness of the present approach by simulating benchmark problems including laminar impinging jets, shear coaxial jet atomization and shear coaxial spray combustion flows.

  13. Advanced Laser Based Measurements in Porous Media Combustion

    NASA Technical Reports Server (NTRS)

    Tedder, Sarah A.

    2009-01-01

    We present measurements using dual-pump dual-broadband coherent anti-Stokes Raman scattering spectroscopy (DP-DBB-CARS) inside a porous media burner. This work continues our previous measurements in such combustion systems. The existing setup was significantly modified with the aim of providing improved data quality and data rate, reduction of interferences and additional species information. These changes are presented and discussed in detail. The CARS technique was expanded to a dual-pump dual-broadband CARS system which in principle enables acquisition of temperatures together with relative H2/N2- and O2/N2- species concentrations. Experimental complexity was reduced by the use of a modified spectrometer enabling the detection of both signals, vibrational and rotational CARS, with only one detection system.

  14. Advanced coal-fueled gas turbine systems: Subscale combustion testing. Topical report, Task 3.1

    SciTech Connect

    Not Available

    1993-05-01

    This is the final report on the Subscale Combustor Testing performed at Textron Defense Systems` (TDS) Haverhill Combustion Laboratories for the Advanced Coal-Fueled Gas Turbine System Program of the Westinghouse Electric Corp. This program was initiated by the Department of Energy in 1986 as an R&D effort to establish the technology base for the commercial application of direct coal-fired gas turbines. The combustion system under consideration incorporates a modular staged, rich-lean-quench, Toroidal Vortex Slogging Combustor (TVC) concept. Fuel-rich conditions in the first stage inhibit NO{sub x} formation from fuel-bound nitrogen; molten coal ash and sulfated sorbent are removed, tapped and quenched from the combustion gases by inertial separation in the second stage. Final oxidation of the fuel-rich gases, and dilution to achieve the desired turbine inlet conditions are accomplished in the third stage, which is maintained sufficiently lean so that here, too, NO{sub x} formation is inhibited. The primary objective of this work was to verify the feasibility of a direct coal-fueled combustion system for combustion turbine applications. This has been accomplished by the design, fabrication, testing and operation of a subscale development-type coal-fired combustor. Because this was a complete departure from present-day turbine combustors and fuels, it was considered necessary to make a thorough evaluation of this design, and its operation in subscale, before applying it in commercial combustion turbine power systems.

  15. Advanced tokamak operating modes in TPX and ITER

    SciTech Connect

    Nevins, W.M.

    1994-12-31

    A program is described to develop the advanced tokamak physics required for an economic steady-state fusion reactor on existing (short-pulse) tokamak experiments; to extend these operating modes to long-pulse on TPX; and finally to demonstrate them in a long-pulse D-T plasma on ITER.

  16. Mechanistic Studies of Combustion and Structure Formation During Synthesis of Advanced Materials

    NASA Technical Reports Server (NTRS)

    Varma, A.; Lau, C.; Mukasyan, A. S.

    2001-01-01

    Combustion in a variety of heterogeneous systems, leading to the synthesis of advanced materials, is characterized by high temperatures (2000-3500 K) and heating rates (up to 10(exp 6) K/s) at and ahead of the reaction front. These high temperatures generate liquids and gases which are subject to gravity-driven flow. The removal of such gravitational effects is likely to provide increased control of the reaction front, with a consequent improvement in control of the microstructure of the synthesized products. Thus, microgravity (mu-g) experiments lead to major advances in the understanding of fundamental aspects of combustion and structure formation under the extreme conditions of the combustion synthesis (CS) wave. In addition, the specific features of microgravity environment allow one to produce unique materials, which cannot be obtained under terrestrial conditions. The current research is a logic continuation of our previous work on investigations of the fundamental phenomena of combustion and structure formation that occur at the high temperatures achieved in a CS wave. Our research is being conducted in three main directions: 1) Microstructural Transformations during Combustion Synthesis of Metal-Ceramic Composites. The studies are devoted to the investigation of particle growth during CS of intermetallic-ceramic composites, synthesized from nickel, aluminum, titanium, and boron metal reactants. To determine the mechanisms of particle growth, the investigation varies the relative amount of components in the initial mixture to yield combustion wave products with different ratios of solid and liquid phases, under 1g and mu-g conditions; 2) Mechanisms of Heat Transfer during Reactions in Heterogeneous Media. Specifically, new phenomena of gasless combustion wave propagation in heterogeneous media with porosity higher than that achievable in normal gravity conditions, are being studied. Two types of mixtures are investigated: clad powders, where contact between

  17. Gravitational Effects on Combustion Synthesis of Advanced Porous Materials

    NASA Technical Reports Server (NTRS)

    Zhang, X.; Moore, J. J.; Schowengerdt, F. D.; Thorne, K.

    2000-01-01

    Combustion Synthesis (self-Propagating high-temperature synthesis-(SHS)) of porous Ti-TiB(x), composite materials has been studied with respect to the sensitivity to the SHS reaction parameters of stoichiometry, green density, gasifying agents, ambient pressure, diluents and gravity. The main objective of this research program is to engineer the required porosity and mechanical properties into the composite materials to meet the requirements of a consumer, such as for the application of bone replacement materials. Gravity serves to restrict the gas expansion and the liquid movement during SHS reaction. As a result, gravitational forces affect the microstructure and properties of the SHS products. Reacting these SHS systems in low gravity in the KC-135 aircraft has extended the ability to form porous products. This paper will emphasize the effects of gravity (low g, 1g and 2g) on the SHS reaction process, and the microstructure and properties of the porous composite. Some of biomedical results are also discussed.

  18. Combustion

    NASA Technical Reports Server (NTRS)

    Bulzan, Dan

    2007-01-01

    An overview of the emissions related research being conducted as part of the Fundamental Aeronautics Subsonics Fixed Wing Project is presented. The overview includes project metrics, milestones, and descriptions of major research areas. The overview also includes information on some of the emissions research being conducted under NASA Research Announcements. Objective: Development of comprehensive detailed and reduced kinetic mechanisms of jet fuels for chemically-reacting flow modeling. Scientific Challenges: 1) Developing experimental facilities capable of handling higher hydrocarbons and providing benchmark combustion data. 2) Determining and understanding ignition and combustion characteristics, such as laminar flame speeds, extinction stretch rates, and autoignition delays, of jet fuels and hydrocarbons relevant to jet surrogates. 3) Developing comprehensive kinetic models for jet fuels.

  19. A predication model for combustion modes of the scramjet-powered aerospace vehicle based on the nonlinear features of the isolator flow field

    NASA Astrophysics Data System (ADS)

    Yang, Qingchun; Wang, Hongxin; Chetehouna, Khaled; Gascoin, Nicolas

    2017-01-01

    The supersonic combustion ramjet (scramjet) engine remains the most promising airbreathing engine cycle for hypersonic flight, particularly the high-performance dual-mode scramjet in the range of flight Mach number from 4 to 7, because it can operates under different combustion modes. Isolator is a very key component of the dual-mode scramjet engine. In this paper, nonlinear characteristics of combustion mode transition is theoretically analyzed. The discontinuous sudden changes of static pressure and Mach number are obtained as the mode transition occurs, which emphasizing the importance of predication and control of combustion modes. In this paper, a predication model of different combustion modes is developed based on these these nonlinear features in the isolator flow field. it can provide a valuable reference for control system design of the scramjet-powered aerospace vehicle.

  20. Task 2: Materials for Advanced Boiler and Oxy-combustion Systems

    SciTech Connect

    Holcolm, Gordon R.; McGhee, Barry

    2009-05-01

    The PowerPoint presentation provides an overview of the tasks for the project: Characterize advanced boiler (oxy-fuel combustion, biomass co-fired) gas compositions and ash deposits; Generate critical data on the effects of environmental conditions; develop a unified test method with a view to future standardization; Generate critical data for coating systems for use in advanced boiler systems; Generate critical data for flue gas recycle piping materials for oxy-fuel systems; and, Compile materials performance data from laboratory and pilot plant exposures of candidate alloys for use in advanced boiler systems.

  1. Vacuum Plasma Spray of CuCrNb Alloy for Advanced Liquid - Fuel Combustion Chambers

    NASA Technical Reports Server (NTRS)

    Zimmerman, Frank

    2000-01-01

    The copper-8 atomic percent chromium-4 atomic percent niobium (CuCrNb) alloy was developed by Glenn Research Center (formally Lewis Research Center) as an improved alloy for combustion chamber liners. In comparison to NARloy-Z, the baseline (as in Space Shuttle Main Engine) alloy for such liners, CuCrNb demonstrates mechanical and thermophysical properties equivalent to NARloy-Z, but at temperatures 100 C to 150 C (180 F to 270 F) higher. Anticipated materials related benefits include decreasing the thrust cell liner weight 5% to 20%, increasing the service life at least two fold over current combustion chamber design, and increasing the safety margins available to designers. By adding an oxidation and thermal barrier coating to the liner, the combustion chamber can operate at even higher temperatures. For all these benefits, however, this alloy cannot be formed using conventional casting and forging methods because of the levels of chromium and niobium, which exceed their solubility limit in copper. Until recently, the only forming process that maintains the required microstructure of CrNb intermetallics is powder metallurgy formation of a billet from powder stock, followed by extrusion. This severely limits its usefulness in structural applications, particularly the complex shapes required for combustion chamber liners. Vacuum plasma spray (VPS) has been demonstrated as a method to form structural articles including small combustion chambers from the CuCrNb alloy. In addition, an oxidation and thermal barrier layer can be formed integrally on the hot wall of the liner that improve performance and extend service life. This paper discusses the metallurgy and thermomechanical properties of VPS formed CuCrNb versus the baseline powder metallurgy process, and the manufacturing of small combustion chamber liners at Marshall Space Flight Center using the VPS process. The benefits to advanced propulsion initiatives of using VPS to fabricate combustion chamber liners

  2. Resistive wall mode stabilization by plasma rotation in advanced tokamaks

    NASA Astrophysics Data System (ADS)

    Eriksson, G.

    1996-03-01

    By combining previous results of Betti and Freidberg [Phys. Rev. Lett. 74, 2949 (1995)] and Eriksson [Phys. Plasmas 2, 3095 (1995)], a fully analytical description is obtained for the stabilizing effect of toroidal plasma rotation in a large aspect ratio tokamak surrounded by a resistive wall. As in advanced tokamak configurations with a large fraction of bootstrap current, it is assumed that the current gradient near the plasma edge is large. This assumption enables an analytical analysis of external kink modes with low poloidal mode numbers. An expression is obtained, showing explicitly how the window of stable wall distances depends on the current profile.

  3. Recent advances in large-eddy simulation of spray and coal combustion

    NASA Astrophysics Data System (ADS)

    Zhou, L. X.

    2013-07-01

    Large-eddy simulation (LES) is under its rapid development and is recognized as a possible second generation of CFD methods used in engineering. Spray and coal combustion is widely used in power, transportation, chemical and metallurgical, iron and steel making, aeronautical and astronautical engineering, hence LES of spray and coal two-phase combustion is particularly important for engineering application. LES of two-phase combustion attracts more and more attention; since it can give the detailed instantaneous flow and flame structures and more exact statistical results than those given by the Reynolds averaged modeling (RANS modeling). One of the key problems in LES is to develop sub-grid scale (SGS) models, including SGS stress models and combustion models. Different investigators proposed or adopted various SGS models. In this paper the present author attempts to review the advances in studies on LES of spray and coal combustion, including the studies done by the present author and his colleagues. Different SGS models adopted by different investigators are described, some of their main results are summarized, and finally some research needs are discussed.

  4. Markets for small-scale, advanced coal-combustion technologies

    SciTech Connect

    Placet, M.; Kenkeremath, L.D.; Streets, D.G.; Dials, G.E.; Kern, D.M.; Nehring, J.L.; Szpunar, C.B.

    1988-12-01

    This report examines the potential of using US-developed advanced coal technologies (ACTs) for small combustors in foreign markets; in particular, the market potentials of the member countries of the Organization of Economic Co-operation and Development (OECD) were determined. First, the United States and those OECD countries with very low energy demands were eliminated. The remaining 15 countries were characterized on the basis of eight factors that would influence their decision to use US ACTs: energy plan and situation, dependence on oil and gas imports, experience with coal, residential/commercial energy demand, industrial energy demand, trade relationship with the United States, level of domestic competition with US ACT manufacturers, and environmental pressure to use advanced technology. Each country was rated high, medium-high, low-medium, or low on each factor, based on statistical and other data. The ratings were then used to group the countries in terms of their relative market potential (good, good but with impediments, or limited). The best potential markets appear to be Spain, Italy, turkey, Greece, and Canada. 25 refs., 1 fig., 37 tabs.

  5. An Overview of Combustion Mechanisms and Flame Structures for Advanced Solid Propellants

    NASA Technical Reports Server (NTRS)

    Beckstead, M. W.

    2000-01-01

    Ammonium perchlorate (AP) and cyclotretamethylenetetranitramine (HMX) are two solid ingredients often used in modern solid propellants. Although these two ingredients have very similar burning rates as monopropellants, they lead to significantly different characteristics when combined with binders to form propellants. Part of the purpose of this paper is to relate the observed combustion characteristics to the postulated flame structures and mechanisms for AP and HMX propellants that apparently lead to these similarities and differences. For AP composite, the primary diffusion flame is more energetic than the monopropellant flame, leading to an increase in burning rate over the monopropellant rate. In contrast the HMX primary diffusion flame is less energetic than the HMX monopropellant flame and ultimately leads to a propellant rate significantly less than the monopropellant rate in composite propellants. During the past decade the search for more energetic propellants and more environmentally acceptable propellants is leading to the development of propellants based on ingredients other than AP and HMX. The objective of this paper is to utilize the more familiar combustion characteristics of AP and HMX containing propellants to project the combustion characteristics of propellants made up of more advanced ingredients. The principal conclusion reached is that most advanced ingredients appear to burn by combustion mechanisms similar to HMX containing propellants rather than AP propellants.

  6. Advanced combustion techniques for controlling NO/x/ emissions of high altitude cruise aircraft

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Reck, G. M.

    1976-01-01

    An array of experiments have been and continue to be sponsored and conducted by NASA to explore the potential of advanced combustion techniques for controlling the emissions of aircraft into the upper atmosphere. Of particular concern are the oxides of nitrogen (NO/x/) emissions into the stratosphere. The experiments utilize a wide variety of approaches varying from advanced combustor concepts to fundamental flame tube experiments. Results are presented which indicate that substantial reductions in cruise NO/x/ emissions should be achievable in future aircraft engines. A major NASA program is described which focuses the many fundamental experiments into a planned evolution and demonstration of the prevaporized-premixed combustion technique in a full-scale engine.

  7. Fuels for Advanced Combustion Engines Research Diesel Fuels: Analysis of Physical and Chemical Properties

    SciTech Connect

    Gallant, Tom; Franz, Jim; Alnajjar, Mikhail; Storey, John Morse; Lewis Sr, Samuel Arthur; Sluder, Scott; Cannella, William C; Fairbridge, Craig; Hager, Darcy; Dettman, Heather; Luecke, Jon; Ratcliff, Matthew A.; Zigler, Brad

    2009-01-01

    The CRC Fuels for Advanced Combustion Engines working group has worked to identify a matrix of research diesel fuels for use in advanced combustion research applications. Nine fuels were specified and formulated to investigate the effects of cetane number aromatic content and 90% distillation fraction. Standard ASTM analyses were performed on the fuels as well as GC/MS and /u1H//u1/u3C NMR analyses and thermodynamic characterizations. Details of the actual results of the fuel formulations compared with the design values are presented, as well as results from standard analyses, such as heating value, viscosity and density. Cetane number characterizations were accomplished by using both the engine method and the Ignition Quality Tester (IQT/sT) apparatus.

  8. Design of a prototype Advanced Main Combustion Chamber for the Space Shuttle Main Engine

    NASA Astrophysics Data System (ADS)

    Lackey, J. D.; Myers, W. N.

    1992-07-01

    Development of a prototype advanced main combustion chamber is underway at NASA Marshall Space Flight Center. The Advanced Main Combustion Chamber (AMCC) project is being approached utilizing a 'concurrent engineering' concept where groups from materials, manufacturing, stress, quality, and design are involved from the initiation of the project. The AMCC design has been tailored to be compatible with the investment casting process. Jacket, inlet/outlet manifolds, inlet/outlet neck coolant flow splitters, support ribs, actuator lugs, and engine controller mounting bracket will all be a part of the one-piece AMCC casting. Casting of the AMCC in a one-piece configuration necessitated a method of forming a liner in its structural jacket. A method of vacuum plasma spraying the liner is being developed. In 1994, the AMCC will be hot-fired on the Technology Test Bed Space Shuttle Main Engine.

  9. Advanced Combustion Diagnostics and Control for Furnaces, Fired Heaters and Boilers

    SciTech Connect

    Tate, J. D.; Le, Linh D.; Knittel,Trevor; Cowie, Alan

    2010-03-20

    The objective of this project was to develop and apply enabling tools and methods towards advanced combustion diagnostics and control of fired-equipment in large-scale petrochemical manufacturing. There are a number of technology gaps and opportunities for combustion optimization, including technologies involving advanced in-situ measurements, modeling, and thermal imaging. These technologies intersect most of manufacturing and energy systems within the chemical industry. This project leveraged the success of a previous DOE funded project led by Dow, where we co-developed an in-situ tunable diode laser (TDL) analyzer platform (with Analytical Specialties Inc, now owned by Yokogawa Electric Corp.). The TDL platform has been tested and proven in a number of combustion processes within Dow and outside of Dow. The primary focus of this project was on combustion diagnostics and control applied towards furnaces, fired heaters and boilers. Special emphasis was placed on the development and application of in-situ measurements for O2, CO and methane since these combustion gases are key variables in optimizing and controlling combustion processes safely. Current best practice in the industry relies on measurements that suffer from serious performance gaps such as limited sampling volume (point measurements), poor precision and accuracy, and poor reliability. Phase I of the project addressed these gaps by adding improved measurement capabilities such as CO and methane (ppm analysis at combustion zone temperatures) as well as improved optics to maintain alignment over path lengths up to 30 meters. Proof-of-concept was demonstrated on a modern olefins furnace located at Dow Chemical's facility in Freeport TX where the improved measurements were compared side-by-side to accepted best practice techniques (zirconium oxide and catalytic bead or thick film sensors). After developing and installing the improved combustion measurements (O2, CO, and methane), we also demonstrated the

  10. A numerical study on combustion process in a small compression ignition engine run dual-fuel mode (diesel-biogas)

    NASA Astrophysics Data System (ADS)

    Ambarita, H.; Widodo, T. I.; Nasution, D. M.

    2017-01-01

    In order to reduce the consumption of fossil fuel of a compression ignition (CI) engines which is usually used in transportation and heavy machineries, it can be operated in dual-fuel mode (diesel-biogas). However, the literature reviews show that the thermal efficiency is lower due to incomplete combustion process. In order to increase the efficiency, the combustion process in the combustion chamber need to be explored. Here, a commercial CFD code is used to explore the combustion process of a small CI engine run on dual fuel mode (diesel-biogas). The turbulent governing equations are solved based on finite volume method. A simulation of compression and expansions strokes at an engine speed and load of 1000 rpm and 2500W, respectively has been carried out. The pressure and temperature distributions and streamlines are plotted. The simulation results show that at engine power of 732.27 Watt the thermal efficiency is 9.05%. The experiment and simulation results show a good agreement. The method developed in this study can be used to investigate the combustion process of CI engine run on dual-fuel mode.

  11. Advanced combustion, emission control, health impacts, and fuels merit review and peer evaluation

    SciTech Connect

    None, None

    2006-10-01

    This report is a summary and analysis of comments from the Advisory Panel at the FY 2006 DOE National Laboratory Advanced Combustion, Emission Control, Health Impacts, and Fuels Merit Review and Peer Evaluation, held May 15-18, 2006 at Argonne National Laboratory. The work evaluated in this document supports the FreedomCAR and Vehicle Technologies Program. The results of this merit review and peer evaluation are major inputs used by DOE in making its funding decisions for the upcoming fiscal year.

  12. High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner For Advanced Rocket Engines

    NASA Technical Reports Server (NTRS)

    Bhat, Biliyar N.; Ellis, David; Singh, Jogender

    2014-01-01

    Advanced high thermal conductivity materials research conducted at NASA Marshall Space Flight Center (MSFC) with state of the art combustion chamber liner material NARloy-Z showed that its thermal conductivity can be increased significantly by adding diamond particles and sintering it at high temperatures. For instance, NARloy-Z containing 40 vol. percent diamond particles, sintered at 975C to full density by using the Field assisted Sintering Technology (FAST) showed 69 percent higher thermal conductivity than baseline NARloy-Z. Furthermore, NARloy-Z-40vol. percent D is 30 percent lighter than NARloy-Z and hence the density normalized thermal conductivity is 140 percent better. These attributes will improve the performance and life of the advanced rocket engines significantly. By one estimate, increased thermal conductivity will directly translate into increased turbopump power up to 2X and increased chamber pressure for improved thrust and ISP, resulting in an expected 20 percent improvement in engine performance. Follow on research is now being conducted to demonstrate the benefits of this high thermal conductivity NARloy-Z-D composite for combustion chamber liner applications in advanced rocket engines. The work consists of a) Optimizing the chemistry and heat treatment for NARloy-Z-D composite, b) Developing design properties (thermal and mechanical) for the optimized NARloy-Z-D, c) Fabrication of net shape subscale combustion chamber liner, and d) Hot fire testing of the liner for performance. FAST is used for consolidating and sintering NARlo-Z-D. The subscale cylindrical liner with built in channels for coolant flow is also fabricated near net shape using the FAST process. The liner will be assembled into a test rig and hot fire tested in the MSFC test facility to determine performance. This paper describes the development of this novel high thermal conductivity NARloy-Z-D composite material, and the advanced net shape technology to fabricate the combustion

  13. Robust Low Cost Liquid Rocket Combustion Chamber by Advanced Vacuum Plasma Process

    NASA Technical Reports Server (NTRS)

    Holmes, Richard; Elam, Sandra; McKechnie, Timothy; Hickman, Robert; Stinson, Thomas N. (Technical Monitor)

    2002-01-01

    Next-generation, regeneratively cooled rocket engines require materials that can meet high temperatures while resisting the corrosive oxidation-reduction reaction of combustion known as blanching, the main cause of engine failure. A project was initiated at NASA-Marshal Space Flight Center (MSFC) to combine three existing technologies to build and demonstrate an advanced liquid rocket engine combustion chamber that would provide a 100 mission life. Technology developed in microgravity research to build cartridges for space furnaces was utilized to vacuum plasma spray (VPS) a functional gradient coating on the hot wall of the combustion liner as one continuous operation, eliminating any bondline between the coating and the liner. The coating was NiCrAlY, developed previously as durable protective coatings on space shuttle high pressure fuel turbopump (HPFTP) turbine blades. A thermal model showed that 0.03 in. NiCrAlY applied to the hot wall of the combustion liner would reduce the hot wall temperature 200 F, a 20% reduction, for longer life. Cu-8Cr-4Nb alloy, which was developed by NASA-Glenn Research Center (GRC), and which possesses excellent high temperature strength, creep resistance, and low cycle fatigue behavior combined with exceptional thermal stability, was utilized as the liner material in place of NARloy-Z. The Cu-8Cr-4Nb material exhibits better mechanical properties at 650 C (1200 F) than NARloy-Z does at 538 C (1000 F). VPS formed Cu-8Cr-4Nb combustion chamber liners with a protective NiCrAlY functional gradient coating have been hot fire tested, successfully demonstrating a durable coating for the first time. Hot fire tests along with tensile and low cycle fatigue properties of the VPS formed combustion chamber liners and witness panel specimens are discussed.

  14. Comparison of a Structured-LES and an Unstructured-DES Code for Predicting Combustion Instabilities in a Longitudinal Mode Rocket

    DTIC Science & Technology

    2014-12-01

    Structured-LES and an Unstructured-DES Code for Predicting Combustion Instabilities in a Longitudinal Mode Rocket 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...Predicting Combustion Instabilities in a Longitudinal Mode Rocket Matt Harvazinski, Doug Tally, & Venke Sankaran Air Force Research Laboratory Edwards

  15. Edge-coherent-mode nature of the small edge localized modes in Experimental Advanced Superconducting Tokamak

    NASA Astrophysics Data System (ADS)

    Wang, H. Q.; Xu, G. S.; Guo, H. Y.; Wan, B. N.; Wang, L.; Chen, R.; Ding, S. Y.; Yan, N.; Gong, X. Z.; Liu, S. C.; Shao, L. M.; Chen, L.; Zhang, W.; Liang, Y. F.; Hu, G. H.; Liu, Y. L.; Li, Y. L.; Zhao, N.

    2014-09-01

    High-confinement regime with high-frequency and low-energy-loss small edge localized modes (ELMs) was achieved in Experimental Advanced Superconducting Tokamak by using the lower hybrid current drive and ion cyclotron resonance heating with lithium wall conditioning. The small ELMs are usually accompanied with a quasi-coherent mode at frequency around 30 kHz, as detected by the Langmuir probes near the separatrix. The coherent mode, with weak magnetic perturbations different from the precursor of conventional ELMs, propagates in the electron diamagnetic drift direction in the lab frame with the poloidal wavelength λθ ˜ 14 cm, corresponding to both high poloidal and toroidal mode numbers (m > 60 and n > 12). This coherent mode, carrying high-temperature high-density filament-like plasma, drives considerable transport from the pedestal region into the scrape-off layer towards divertor region. The co-existence of small ELMs and quasi-coherent modes is beneficial for the sustainment of long pulse H-mode regime without significant confinement degradation.

  16. Mechanistic Studies Of Combustion And Structure Formation During Combustion Synthesis Of Advanced Materials: Phase Separation Mechanism For Bio-Alloys

    NASA Technical Reports Server (NTRS)

    Varma, A.; Lau, C.; Mukasyan, A.

    2003-01-01

    Among all implant materials, Co-Cr-Mo alloys demonstrate perhaps the most useful balance of resistance to corrosion, fatigue and wear, along with strength and biocompatibility [1]. Currently, these widely used alloys are produced by conventional furnace technology. Owing to high melting points of the main alloy elements (e.g. Tm.p.(Co) 1768 K), high-temperature furnaces and long process times (several hours) are required. Therefore, attempts to develop more efficient and flexible methods for production of such alloys with superior properties are of great interest. The synthesis of materials using combustion phenomena is an advanced approach in powder metallurgy [2]. The process is characterized by unique conditions involving extremely fast heating rates (up to 10(exp 6 K/s), high temperatures (up to 3500 K), and short reaction times (on the order of seconds). As a result, combustion synthesis (CS) offers several attractive advantages over conventional metallurgical processing and alloy development technologies. The foremost is that solely the heat of chemical reaction (instead of an external source) supplies the energy for the synthesis. Also, simple equipment, rather than energy-intensive high-temperature furnaces, is sufficient. This work was devoted to experiments on CS of Co-based alloys by utilizing thermite (metal oxide-reducing metal) reactions, where phase separation subsequently produces materials with tailored compositions and properties. Owing to high reaction exothermicity, the CS process results in a significant increase of temperature (up to 3000 C), which is higher than melting points of all products. Since the products differ in density, phase separation may be a gravitydriven process: the heavy (metallic phase) settles while the light (slag) phase floats. The goal was to determine if buoyancy is indeed the major mechanism that controls phase segregation.

  17. A flammability and combustion model for integrated accident analysis. [Advanced light water reactors

    SciTech Connect

    Plys, M.G.; Astleford, R.D.; Epstein, M. )

    1988-01-01

    A model for flammability characteristics and combustion of hydrogen and carbon monoxide mixtures is presented for application to severe accident analysis of Advanced Light Water Reactors (ALWR's). Flammability of general mixtures for thermodynamic conditions anticipated during a severe accident is quantified with a new correlation technique applied to data for several fuel and inertant mixtures and using accepted methods for combining these data. Combustion behavior is quantified by a mechanistic model consisting of a continuity and momentum balance for the burned gases, and considering an uncertainty parameter to match the idealized process to experiment. Benchmarks against experiment demonstrate the validity of this approach for a single recommended value of the flame flux multiplier parameter. The models presented here are equally applicable to analysis of current LWR's. 21 refs., 16 figs., 6 tabs.

  18. Robust Low Cost Liquid Rocket Combustion Chamber by Advanced Vacuum Plasma Process

    NASA Technical Reports Server (NTRS)

    Holmes, Richard; Elam, Sandra; Ellis, David L.; McKechnie, Timothy; Hickman, Robert; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Next-generation, regeneratively cooled rocket engines will require materials that can withstand high temperatures while retaining high thermal conductivity. Fabrication techniques must be cost efficient so that engine components can be manufactured within the constraints of shrinking budgets. Three technologies have been combined to produce an advanced liquid rocket engine combustion chamber at NASA-Marshall Space Flight Center (MSFC) using relatively low-cost, vacuum-plasma-spray (VPS) techniques. Copper alloy NARloy-Z was replaced with a new high performance Cu-8Cr-4Nb alloy developed by NASA-Glenn Research Center (GRC), which possesses excellent high-temperature strength, creep resistance, and low cycle fatigue behavior combined with exceptional thermal stability. Functional gradient technology, developed building composite cartridges for space furnaces was incorporated to add oxidation resistant and thermal barrier coatings as an integral part of the hot wall of the liner during the VPS process. NiCrAlY, utilized to produce durable protective coating for the space shuttle high pressure fuel turbopump (BPFTP) turbine blades, was used as the functional gradient material coating (FGM). The FGM not only serves as a protection from oxidation or blanching, the main cause of engine failure, but also serves as a thermal barrier because of its lower thermal conductivity, reducing the temperature of the combustion liner 200 F, from 1000 F to 800 F producing longer life. The objective of this program was to develop and demonstrate the technology to fabricate high-performance, robust, inexpensive combustion chambers for advanced propulsion systems (such as Lockheed-Martin's VentureStar and NASA's Reusable Launch Vehicle, RLV) using the low-cost VPS process. VPS formed combustion chamber test articles have been formed with the FGM hot wall built in and hot fire tested, demonstrating for the first time a coating that will remain intact through the hot firing test, and with

  19. Combustion synthesis of advanced materials: Studies of the influence of gravity and reaction kinetics

    NASA Astrophysics Data System (ADS)

    Pelekh, Aleksey Yevgeuyevich

    Combustion synthesis is an attractive technique to synthesize a wide variety of advanced materials that include powders and near-net shape products of ceramics, intermetallics, composites and functionally gradient materials. It is also considered to be a valuable method for space applications, because of low energy requirements and simple equipment. However, it is necessary to understand how microgravity influences the combustion mechanism and properties of the synthesized materials. In this work, combustion synthesis experiments were conducted both in normal and in low-gravity conditions, using a unique setup designed and developed for this purpose. Microgravity experiments were done in NASA Lewis Research Center using Drop Tower which provided 2.2 s of 10-5 g level, as well as on-board DC-9 aircraft (20 s of 10-2 g). It was clearly demonstrated that gravity plays an important role during combustion synthesis. It significantly influences both the combustion and structure formation processes. It was also shown that microgravity conditions allow the synthesis of materials with improved micro- and macrostructures. The study of chemical reaction kinetics in combustion synthesis systems is of critical importance. The measurement of kinetic parameters (especially activation energy) and a comparison with known elementary processes provides an insight into the controlling step of the mechanism. In this work, a computer-assisted electrothermography method was developed to determine the intrinsic kinetics of reactions under conditions similar to those realized during combustion synthesis of materials. This technique was applied to investigate the kinetics and other features associated with the reaction of titanium with nitrogen at 1 atm pressure. It was shown that at temperatures below the melting point of titanium, the reaction follows parabolic rate law. The obtained activation energy value is in good agreement with literature data. At higher temperatures, however, the

  20. Numerical exploration of mixing and combustion in a dual-mode combustor with backward-facing steps

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Li, Lang-quan; Yan, Li; Liao, Lei

    2016-10-01

    Dual-mode scramjet combustor is the crucial component for the combined cycle engine of space mission vehicles. The Reynolds Averaged Navier-Stokes (RANS) equations, Spalart-Allmaras turbulence model and the finite-rate reaction model have been utilized to investigate the mixing and combustion in a dual-mode combustor with backward-facing steps, and the species distributions and the Mach number profile of a turbulent diffusion combustion problem have been employed to validate the numerical approach. Moreover, the influences of the injection strategy and the fuel equivalence ratio arrangement on its mixing and combustion flow fields have been explored. The obtained results show that the vertical injection is beneficial for mode transition, and an obvious high pressure region is generated with the vertical injection strategy. Accordingly, its mass-weighted average Mach number drops more sharply. The lower total equivalence ratio is beneficial for the mixing augmentation, as well the smaller fuel equivalence ratio discrepancy. However, the larger total equivalence ratio is beneficial for the mode transition.

  1. Development of Computational Capabilities to Predict the Corrosion Wastage of Boiler Tubes in Advanced Combustion Systems

    SciTech Connect

    Kung, Steven; Rapp, Robert

    2014-08-31

    A comprehensive corrosion research project consisting of pilot-scale combustion testing and long-term laboratory corrosion study has been successfully performed. A pilot-scale combustion facility available at Brigham Young University was selected and modified to enable burning of pulverized coals under the operating conditions typical for advanced coal-fired utility boilers. Eight United States (U.S.) coals were selected for this investigation, with the test conditions for all coals set to have the same heat input to the combustor. In addition, the air/fuel stoichiometric ratio was controlled so that staged combustion was established, with the stoichiometric ratio maintained at 0.85 in the burner zone and 1.15 in the burnout zone. The burner zone represented the lower furnace of utility boilers, while the burnout zone mimicked the upper furnace areas adjacent to the superheaters and reheaters. From this staged combustion, approximately 3% excess oxygen was attained in the combustion gas at the furnace outlet. During each of the pilot-scale combustion tests, extensive online measurements of the flue gas compositions were performed. In addition, deposit samples were collected at the same location for chemical analyses. Such extensive gas and deposit analyses enabled detailed characterization of the actual combustion environments existing at the lower furnace walls under reducing conditions and those adjacent to the superheaters and reheaters under oxidizing conditions in advanced U.S. coal-fired utility boilers. The gas and deposit compositions were then carefully simulated in a series of 1000-hour laboratory corrosion tests, in which the corrosion performances of different commercial candidate alloys and weld overlays were evaluated at various temperatures for advanced boiler systems. Results of this laboratory study led to significant improvement in understanding of the corrosion mechanisms operating on the furnace walls as well as superheaters and reheaters in

  2. Circulating fluidized bed tehnology in biomass combustion-performance, advances and experiences

    SciTech Connect

    Mutanen, K.I.

    1995-11-01

    Development of fluidized bed combustion (FBC) was started both in North America and in Europe in the 1960`s. In Europe and especially in Scandinavia the major driving force behind the development was the need to find new more efficient technologies for utilization of low-grade fuels like different biomasses and wastes. Both bubbling fluidized bed (BFB) and circulating fluidized bed (CFB) technologies were under intensive R&D,D efforts and have now advanced to dominating role in industrial and district heating power plant markets in Europe. New advanced CFB designs are now entering the markets. In North America and especially in the US the driving force behind the FBC development was initially the need to utilize different types of coals in a more efficient and environmentally acceptable way. The present and future markets seem to be mainly in biomass and multifuel applications where there is benefit from high combustion efficiency, high fuel flexibility and low emissions such as in the pulp and paper industry. The choice between CFB technology and BFB technology is based on selected fuels, emission requirements, plant size and on technical and economic feasibility. Based on Scandinavian experience there is vast potential in the North American industry to retrofit existing oil fired, pulverized coal fired, chemical recovery or grate fired boilers with FBC systems or to build a new FBC based boiler plant. This paper will present the status of CFB technologies and will compare technical and economic feasibility of CFB technology to CFB technology to BFB and also to other combustion methods. Power plant projects that are using advanced CFB technology e.g. Ahlstrom Pyroflow Compact technology for biomass firing and co-firing of biomass with other fuels will also be introduced.

  3. Adaptation of the Advanced Spray Combustion Code to Cavitating Flow Problems

    NASA Technical Reports Server (NTRS)

    Liang, Pak-Yan

    1993-01-01

    A very important consideration in turbopump design is the prediction and prevention of cavitation. Thus far conventional CFD codes have not been generally applicable to the treatment of cavitating flows. Taking advantage of its two-phase capability, the Advanced Spray Combustion Code is being modified to handle flows with transient as well as steady-state cavitation bubbles. The volume-of-fluid approach incorporated into the code is extended and augmented with a liquid phase energy equation and a simple evaporation model. The strategy adopted also successfully deals with the cavity closure issue. Simple test cases will be presented and remaining technical challenges will be discussed.

  4. Fuel Effects on Ignition and Their Impact on Advanced Combustion Engines (Poster)

    SciTech Connect

    Taylor, J.; Li, H.; Neill, S.

    2006-08-01

    The objective of this report is to develop a pathway to use easily measured ignition properties as metrics for characterizing fuels in advanced combustion engine research--correlate IQT{trademark} measured parameters with engine data. In HCCL engines, ignition timing depends on the reaction rates throughout compression stroke: need to understand sensitivity to T, P, and [O{sub 2}]; need to rank fuels based on more than one set of conditions; and need to understand how fuel composition (molecular species) affect ignition properties.

  5. Advanced Monitoring to Improve Combustion Turbine/Combined Cycle Reliability, Availability & Maintainability

    SciTech Connect

    Leonard Angello

    2005-09-30

    Power generators are concerned with the maintenance costs associated with the advanced turbines that they are purchasing. Since these machines do not have fully established Operation and Maintenance (O&M) track records, power generators face financial risk due to uncertain future maintenance costs. This risk is of particular concern, as the electricity industry transitions to a competitive business environment in which unexpected O&M costs cannot be passed through to consumers. These concerns have accelerated the need for intelligent software-based diagnostic systems that can monitor the health of a combustion turbine in real time and provide valuable information on the machine's performance to its owner/operators. EPRI, Impact Technologies, Boyce Engineering, and Progress Energy have teamed to develop a suite of intelligent software tools integrated with a diagnostic monitoring platform that, in real time, interpret data to assess the 'total health' of combustion turbines. The 'Combustion Turbine Health Management System' (CTHMS) will consist of a series of 'Dynamic Link Library' (DLL) programs residing on a diagnostic monitoring platform that accepts turbine health data from existing monitoring instrumentation. CTHMS interprets sensor and instrument outputs, correlates them to a machine's condition, provide interpretative analyses, project servicing intervals, and estimate remaining component life. In addition, the CTHMS enables real-time anomaly detection and diagnostics of performance and mechanical faults, enabling power producers to more accurately predict critical component remaining useful life and turbine degradation.

  6. Robust Low Cost Aerospike/RLV Combustion Chamber by Advanced Vacuum Plasma Process

    NASA Technical Reports Server (NTRS)

    Holmes, Richard; Ellis, David; McKechnie

    1999-01-01

    Next-generation, regeneratively cooled rocket engines will require materials that can withstand high temperatures while retaining high thermal conductivity. At the same time, fabrication techniques must be cost efficient so that engine components can be manufactured within the constraints of a shrinking NASA budget. In recent years, combustion chambers of equivalent size to the Aerospike chamber have been fabricated at NASA-Marshall Space Flight Center (MSFC) using innovative, relatively low-cost, vacuum-plasma-spray (VPS) techniques. Typically, such combustion chambers are made of the copper alloy NARloy-Z. However, current research and development conducted by NASA-Lewis Research Center (LeRC) has identified a Cu-8Cr-4Nb alloy which possesses excellent high-temperature strength, creep resistance, and low cycle fatigue behavior combined with exceptional thermal stability. In fact, researchers at NASA-LeRC have demonstrated that powder metallurgy (P/M) Cu-8Cr-4Nb exhibits better mechanical properties at 1,200 F than NARloy-Z does at 1,000 F. The objective of this program was to develop and demonstrate the technology to fabricate high-performance, robust, inexpensive combustion chambers for advanced propulsion systems (such as Lockheed-Martin's VentureStar and NASA's Reusable Launch Vehicle, RLV) using the low-cost, VPS process to deposit Cu-8Cr-4Nb with mechanical properties that match or exceed those of P/M Cu-8Cr-4Nb. In addition, oxidation resistant and thermal barrier coatings can be incorporated as an integral part of the hot wall of the liner during the VPS process. Tensile properties of Cu-8Cr-4Nb material produced by VPS are reviewed and compared to material produced previously by extrusion. VPS formed combustion chamber liners have also been prepared and will be reported on following scheduled hot firing tests at NASA-Lewis.

  7. The monolithic lawn-like CuO-based nanorods array used for diesel soot combustion under gravitational contact mode.

    PubMed

    Yu, Yifu; Meng, Ming; Dai, Fangfang

    2013-02-07

    A simple and feasible contact mode called gravitational contact mode (GCM) was developed for the first time to imitate the practical state between soot and catalyst. By simulating rainwater adsorption on a lawn in nature, we synthesized a lawn-like CuO nanorods array, which exhibited rather good catalytic activity for diesel soot combustion under GCM. Moreover, the CuO nanorods array could serve as a support for composite catalysts through a sequential chemical bath deposition method and exhibited higher catalytic activity than a traditional supported catalyst. The monolithic macroscopic structure of such a catalyst shows its potential for large-scale preparation and application.

  8. Method and apparatus for advanced staged combustion utilizing forced internal recirculation

    SciTech Connect

    Rabovitser, Iosif K.; Knight, Richard A.; Cygan, David F.; Nester, Serguei; Abbasi, Hamid A.

    2003-12-16

    A method and apparatus for combustion of a fuel in which a first-stage fuel and a first-stage oxidant are introduced into a combustion chamber and ignited, forming a primary combustion zone. At least about 5% of the total heat output produced by combustion of the first-stage fuel and the first-stage oxidant is removed from the primary combustion zone, forming cooled first-stage combustion products. A portion of the cooled first-stage combustion products from a downstream region of the primary combustion zone is recirculated to an upstream region of primary combustion zone. A second-stage fuel is introduced into the combustion chamber downstream of the primary combustion zone and ignited, forming a secondary combustion zone. At least about 5% of the heat from the secondary combustion zone is removed. In accordance with one embodiment, a third-stage oxidant is introduced into the combustion chamber downstream of the secondary combustion zone, forming a tertiary combustion zone.

  9. The monolithic lawn-like CuO-based nanorods array used for diesel soot combustion under gravitational contact mode

    NASA Astrophysics Data System (ADS)

    Yu, Yifu; Meng, Ming; Dai, Fangfang

    2013-01-01

    A simple and feasible contact mode called gravitational contact mode (GCM) was developed for the first time to imitate the practical state between soot and catalyst. By simulating rainwater adsorption on a lawn in nature, we synthesized a lawn-like CuO nanorods array, which exhibited rather good catalytic activity for diesel soot combustion under GCM. Moreover, the CuO nanorods array could serve as a support for composite catalysts through a sequential chemical bath deposition method and exhibited higher catalytic activity than a traditional supported catalyst. The monolithic macroscopic structure of such a catalyst shows its potential for large-scale preparation and application.A simple and feasible contact mode called gravitational contact mode (GCM) was developed for the first time to imitate the practical state between soot and catalyst. By simulating rainwater adsorption on a lawn in nature, we synthesized a lawn-like CuO nanorods array, which exhibited rather good catalytic activity for diesel soot combustion under GCM. Moreover, the CuO nanorods array could serve as a support for composite catalysts through a sequential chemical bath deposition method and exhibited higher catalytic activity than a traditional supported catalyst. The monolithic macroscopic structure of such a catalyst shows its potential for large-scale preparation and application. Electronic supplementary information (ESI) available: The photo of mimic target and SEM images. See DOI: 10.1039/c2nr33269h

  10. ADVANCED MONITORING TO IMPROVE COMBUSTION TURBINE (CT)/COMBINED CYCLE (CC) RELIABILITY, AVAILABILITY AND MAINTAINABILITY (RAM)

    SciTech Connect

    Leonard Angello

    2002-04-01

    Power generators are concerned with the maintenance costs associated with the advanced turbines that they are purchasing. Since these machines do not have fully established operation and maintenance (O&M) track records, power generators face financial risk due to uncertain future maintenance costs. This risk is of particular concern, as the electricity industry transitions to a competitive business environment in which unexpected O&M costs cannot be passed through to consumers. These concerns have accelerated the need for intelligent software-based diagnostic systems that can monitor the health of a combustion turbine in real time and provide valuable information on the machine's performance to its owner/operators. Such systems would interpret sensor and instrument outputs, correlate them to the machine's condition, provide interpretative analyses, forward projections of servicing intervals, estimate remaining component life, and identify faults. EPRI, Impact Technologies, Boyce Engineering, and Progress Energy have teamed to develop a suite of intelligent software tools integrated with a diagnostic monitoring platform that will, in real time, interpret data to assess the ''total health'' of combustion turbines. The Combustion Turbine Health Management System (CTHM) will consist of a series of dynamic link library (DLL) programs residing on a diagnostic monitoring platform that accepts turbine health data from existing monitoring instrumentation. The CTHM system will be a significant improvement over currently available techniques for turbine monitoring and diagnostics. CTHM will interpret sensor and instrument outputs, correlate them to a machine's condition, provide interpretative analyses, project servicing intervals, and estimate remaining component life. In addition, it will enable real-time anomaly detection and diagnostics of performance and mechanical faults, enabling power producers to more accurately predict critical component remaining useful life and

  11. Observation of pedestal turbulence in edge localized mode-free H-mode on experimental advanced superconducting tokamak

    SciTech Connect

    Han, X. Zhang, T.; Zhang, S. B.; Wang, Y. M.; Shi, T. H.; Liu, Z. X.; Kong, D. F.; Qu, H.; Gao, X.

    2014-10-15

    Two different pedestal turbulence structures have been observed in edge localized mode-free phase of H-mode heated by lower hybrid wave and RF wave in ion cyclotron range of frequencies (ICRF) on experimental advanced superconducting tokamak. When the fraction of ICRF power P{sub ICRF}/P{sub total} exceeds 0.7, coherent mode is observed. The mode is identified as an electromagnetic mode, rotating in electron diamagnetic direction with a frequency around 50 kHz and toroidal mode number n = −3. Whereas when P{sub ICRF}/P{sub total} is less than 0.7, harmonic mode with frequency f = 40–300 kHz appears instead. The characteristics of these two modes are demonstrated preliminarily. The threshold value of heating power and also the plasma parameters are distinct.

  12. Simultaneous dual mode combustion engine operating on spark ignition and homogenous charge compression ignition

    DOEpatents

    Fiveland, Scott B.; Wiggers, Timothy E.

    2004-06-22

    An engine particularly suited to single speed operation environments, such as stationary power generators. The engine includes a plurality of combustion cylinders operable under homogenous charge compression ignition, and at least one combustion cylinder operable on spark ignition concepts. The cylinder operable on spark ignition concepts can be convertible to operate under homogenous charge compression ignition. The engine is started using the cylinders operable under spark ignition concepts.

  13. Advanced exergoenvironmental analysis of a near-zero emission power plant with chemical looping combustion.

    PubMed

    Petrakopoulou, Fontina; Tsatsaronis, George; Morosuk, Tatiana

    2012-03-06

    Carbon capture and storage (CCS) from power plants can be used to mitigate CO(2) emissions from the combustion of fossil fuels. However, CCS technologies are energy intensive, decreasing the operating efficiency of a plant and increasing its costs. Recently developed advanced exergy-based analyses can uncover the potential for improvement of complex energy conversion systems, as well as qualify and quantify plant component interactions. In this paper, an advanced exergoenvironmental analysis is used for the first time as means to evaluate an oxy-fuel power plant with CO(2) capture. The environmental impacts of each component are split into avoidable/unavoidable and endogenous/exogenous parts. In an effort to minimize the environmental impact of the plant operation, we focus on the avoidable part of the impact (which is also split into endogenous and exogenous parts) and we seek ways to decrease it. The results of the advanced exergoenvironmental analysis show that the majority of the environmental impact related to the exergy destruction of individual components is unavoidable and endogenous. Thus, the improvement potential is rather limited, and the interactions of the components are of lower importance. The environmental impact of construction of the components is found to be significantly lower than that associated with their operation; therefore, our suggestions for improvement focus on measures concerning the reduction of exergy destruction and pollutant formation.

  14. Linkages from DOE’s Vehicle Technologies R&D in Advanced Combustion to More Efficient, Cleaner-Burning Engines

    SciTech Connect

    Ruegg, Rosalie; Thomas, Patrick

    2011-06-01

    This report uses bibliometric analysis, supported by interview and review of documents and databases, to trace linkages from knowledge outputs resulting from DOE's advances in vehicle engine combustion to downstream innovations in commercial diesel engines and other areas. This analysis covers the period from 1974 through 2008 (and in some cases to early 2009).

  15. SYMPOSIUM ON TURBULENCE AND COMBUSTION - SPECIAL SYMPOSIUM TO BRING TOGETHER TOP RESEARCHERS IN THE FIELDS OF FLUID TURBULENCE AND COMBUSTION TO PROMOTE ADVANCES IN TURBULENT, REACTING FLOWS

    SciTech Connect

    Caughey, David

    2010-10-08

    A Symposium on Turbulence and Combustion was held at Cornell University on August 3-4, 2009. The overall goal of the Symposium was to promote future advances in the study of turbulence and combustion, through an unique forum intended to foster interactions between leading members of these two research communities. The Symposium program consisted of twelve invited lectures given by world-class experts in these fields, two poster sessions consisting of nearly 50 presentations, an open forum, and other informal activities designed to foster discussion. Topics covered in the lectures included turbulent dispersion, wall-bounded flows, mixing, finite-rate chemistry, and others, using experiment, modeling, and computations, and included perspectives from an international community of leading researchers from academia, national laboratories, and industry.

  16. Some Effects of Injection Advance Angle, Engine-Jacket Temperature, and Speed on Combustion in a Compression-Ignition Engine

    NASA Technical Reports Server (NTRS)

    Rothrock, A M; Waldron, C D

    1936-01-01

    An optical indicator and a high-speed motion-picture camera capable of operating at the rate of 2,000 frames per second were used to record simultaneously the pressure development and the flame formation in the combustion chamber of the NACA combustion apparatus. Tests were made at engine speeds of 570 and 1,500 r.p.m. The engine-jacket temperature was varied from 100 degrees to 300 degrees F. And the injection advance angle from 13 degrees after top center to 120 degrees before top center. The results show that the course of the combustion is largely controlled by the temperature and pressure of the air in the chamber from the time the fuel is injected until the time at which combustion starts and by the ignition lag. The conclusion is presented that in a compression-ignition engine with a quiescent combustion chamber the ignition lag should be the longest that can be used without excessive rates of pressure rise; any further shortening of the ignition lag decreased the effective combustion of the engine.

  17. Influence of Boundary Condition Treatment on Longitudinal Mode Combustion Instability Predictions

    DTIC Science & Technology

    2013-07-01

    Approved for Public Release; Distribution Unlimited. PA#13361 13. SUPPLEMENTARY NOTES Conference paper for the 49th AIAA/ASME/ SAE /ASEE Joint...by the DoD High Performance Computing Modernization Program. References 1Yu, Y., Sisco, J ., Rosen, S., Madhav, A., and Anderson, W., “Spontaneous...Harvazinski, M., Merkle, C., and Anderson, W., “Comparison Between Simulation and Measurement of Self- Excited Combustion Instability,” 48th AIAA/ASME/ SAE /ASEE

  18. Fabrication of High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner for Advanced Rocket Engines

    NASA Technical Reports Server (NTRS)

    Bhat, Biliyar N.; Greene, Sandra E.; Singh, Jogender

    2016-01-01

    NARloy-Z alloy (Cu-3 percent, Ag-0.5 percent, Zr) is a state of the art alloy currently used for fabricating rocket engine combustion chamber liners. Research conducted at NASA-MSFC and Penn State – Applied Research Laboratory has shown that thermal conductivity of NARloy-Z can be increased significantly by adding diamonds to form a composite (NARloy-Z-D). NARloy-Z-D is also lighter than NARloy-Z. These attributes make this advanced composite material an ideal candidate for fabricating combustion chamber liner for an advanced rocket engine. Increased thermal conductivity will directly translate into increased turbopump power and increased chamber pressure for improved thrust and specific impulse. This paper describes the process development for fabricating a subscale high thermal conductivity NARloy-Z-D combustion chamber liner using Field Assisted Sintering Technology (FAST). The FAST process uses a mixture of NARloy-Z and diamond powders which is sintered under pressure at elevated temperatures. Several challenges were encountered, i.e., segregation of diamonds, machining the super hard NARloy-Z-D composite, net shape fabrication and nondestructive examination. The paper describes how these challenges were addressed. Diamonds coated with copper (CuD) appear to give the best results. A near net shape subscale combustion chamber liner is being fabricated by diffusion bonding cylindrical rings of NARloy-Z-CuD using the FAST process.

  19. Introductory lecture. Advanced laser spectroscopy in combustion chemistry: from elementary steps to practical devices.

    PubMed

    Wolfrum, J

    2001-01-01

    In recent years a large number of linear and nonlinear laser-based diagnostic techniques for nonintrusive measurements of species concentrations, temperatures, and gas velocities in a wide pressure and temperature range with high temporal and spatial resolution have been developed and have become extremely valuable tools to study many aspects of combustion. Beside the nonintrusive diagnostics of technical combustion devices the kinetics and microscopic dynamics of elementary chemical combustion reactions can be investigated in great detail by laser spectroscopy. These investigations show, that a small number of relatively simple elementary steps like H + O2-->OH + O, H2O2-->2OH, O + N2-->NO + N, NH2 + NO-->H2O + N2, OH + N2H control a large variety of combustion phenomena and pollutant formation processes. Laminar flames are ideal objects to develop the application of laser spectroscopic methods for practical combustion systems and to test and improve the gas-phase reaction mechanism in combustion models. Nonintrusive laser point and field measurements are of basic importance in the validation and further development of turbulent combustion models. Nonlinear laser spectroscopic techniques using infrared-visible sum-frequency generation can now bridge the pressure and materials gap to provide kinetic data for catalytic combustion. Finally, the potential of laser techniques for active combustion control in municipal waste incinerators is illustrated.

  20. RF-driven advanced modes of ITER operation

    SciTech Connect

    Garcia, J.; Artaud, J. F.; Basiuk, V.; Decker, J.; Giruzzi, G.; Hawkes, N.; Imbeaux, F.; Litaudon, X.; Mailloux, J.; Peysson, Y.; Schneider, M.; Brix, M.

    2009-11-26

    The impact of the Radio Frequency heating and current drive systems on the ITER advanced scenarios is analyzed by means of the CRONOS suite of codes for integrated tokamak modelling. As a first step, the code is applied to analyze a high power advanced scenario discharge of JET in order to validate both the heating and current drive modules and the overall simulation procedure. Then, ITER advanced scenarios, based on Radio Frequency systems, are studied on the basis of previous results. These simulations show that both hybrid and steady-state scenarios could be possible within the ITER specifications, using RF heating and current drive only.

  1. RF-driven advanced modes of ITER operation

    NASA Astrophysics Data System (ADS)

    Garcia, J.; Artaud, J. F.; Basiuk, V.; Brix, M.; Decker, J.; Giruzzi, G.; Hawkes, N.; Imbeaux, F.; Litaudon, X.; Mailloux, J.; Peysson, Y.; Schneider, M.

    2009-11-01

    The impact of the Radio Frequency heating and current drive systems on the ITER advanced scenarios is analyzed by means of the CRONOS suite of codes for integrated tokamak modelling. As a first step, the code is applied to analyze a high power advanced scenario discharge of JET in order to validate both the heating and current drive modules and the overall simulation procedure. Then, ITER advanced scenarios, based on Radio Frequency systems, are studied on the basis of previous results. These simulations show that both hybrid and steady-state scenarios could be possible within the ITER specifications, using RF heating and current drive only.

  2. Advanced Optical Diagnostic Methods for Describing Fuel Injection and Combustion Flowfield Phenomena

    NASA Technical Reports Server (NTRS)

    Locke, Randy J.; Hicks, Yolanda R.; Anderson, Robert C.

    2004-01-01

    Over the past decade advanced optical diagnostic techniques have evolved and matured to a point where they are now widely applied in the interrogation of high pressure combusting flows. At NASA Glenn Research Center (GRC), imaging techniques have been used successfully in on-going work to develop the next generation of commercial aircraft gas turbine combustors. This work has centered on providing a means by which researchers and designers can obtain direct visual observation and measurements of the fuel injection/mixing/combustion processes and combustor flowfield in two- and three-dimensional views at actual operational conditions. Obtaining a thorough understanding of the chemical and physical processes at the extreme operating conditions of the next generation of combustors is critical to reducing emissions and increasing fuel efficiency. To accomplish this and other tasks, the diagnostic team at GRC has designed and constructed optically accessible, high pressurer high temperature flame tubes and sectar rigs capable of optically probing the 20-60 atm flowfields of these aero-combustors. Among the techniques employed at GRC are planar laser-induced fluorescence (PLIF) for imaging molecular species as well as liquid and gaseous fuel; planar light scattering (PLS) for imaging fuel sprays and droplets; and spontaneous Raman scattering for species and temperature measurement. Using these techniques, optical measurements never before possible have been made in the actual environments of liquid fueled gas turbines. 2-D mapping of such parameters as species (e.g. OH-, NO and kerosene-based jet fuel) distribution, injector spray angle, and fuel/air distribution are just some of the measurements that are now routinely made. Optical imaging has also provided prompt feedback to researchers regarding the effects of changes in the fuel injector configuration on both combustor performance and flowfield character. Several injector design modifications and improvements have

  3. Development of an Advanced Flameless Combustion Heat Source Utilizing Heavy Fuels

    DTIC Science & Technology

    2010-07-01

    captive flameless heat generation. CDI’s unique success in achieving stabilization in captive combustion for light fuels such as methanol, ethanol and...7 4.3.2 Light Fuel Testing/Calibration (Methanol and Ethanol ).............................................. 10 4.3.3 Heavy Fuel Testing...9 Figure 3. Catalytic Combustion Data for Methanol & Ethanol ...................................................11 Figure 4. Catalytic

  4. Active Combustion Control for Aircraft Gas-Turbine Engines-Experimental Results for an Advanced, Low-Emissions Combustor Prototype

    NASA Technical Reports Server (NTRS)

    DeLaat, John C.; Kopasakis, George; Saus, Joseph R.; Chang, Clarence T.; Wey, Changlie

    2012-01-01

    Lean combustion concepts for aircraft engine combustors are prone to combustion instabilities. Mitigation of instabilities is an enabling technology for these low-emissions combustors. NASA Glenn Research Center s prior activity has demonstrated active control to suppress a high-frequency combustion instability in a combustor rig designed to emulate an actual aircraft engine instability experience with a conventional, rich-front-end combustor. The current effort is developing further understanding of the problem specifically as applied to future lean-burning, very low-emissions combustors. A prototype advanced, low-emissions aircraft engine combustor with a combustion instability has been identified and previous work has characterized the dynamic behavior of that combustor prototype. The combustor exhibits thermoacoustic instabilities that are related to increasing fuel flow and that potentially prevent full-power operation. A simplified, non-linear oscillator model and a more physics-based sectored 1-D dynamic model have been developed to capture the combustor prototype s instability behavior. Utilizing these models, the NASA Adaptive Sliding Phasor Average Control (ASPAC) instability control method has been updated for the low-emissions combustor prototype. Active combustion instability suppression using the ASPAC control method has been demonstrated experimentally with this combustor prototype in a NASA combustion test cell operating at engine pressures, temperatures, and flows. A high-frequency fuel valve was utilized to perturb the combustor fuel flow. Successful instability suppression was shown using a dynamic pressure sensor in the combustor for controller feedback. Instability control was also shown with a pressure feedback sensor in the lower temperature region upstream of the combustor. It was also demonstrated that the controller can prevent the instability from occurring while combustor operation was transitioning from a stable, low-power condition to

  5. Computational Combustion

    SciTech Connect

    Westbrook, C K; Mizobuchi, Y; Poinsot, T J; Smith, P J; Warnatz, J

    2004-08-26

    Progress in the field of computational combustion over the past 50 years is reviewed. Particular attention is given to those classes of models that are common to most system modeling efforts, including fluid dynamics, chemical kinetics, liquid sprays, and turbulent flame models. The developments in combustion modeling are placed into the time-dependent context of the accompanying exponential growth in computer capabilities and Moore's Law. Superimposed on this steady growth, the occasional sudden advances in modeling capabilities are identified and their impacts are discussed. Integration of submodels into system models for spark ignition, diesel and homogeneous charge, compression ignition engines, surface and catalytic combustion, pulse combustion, and detonations are described. Finally, the current state of combustion modeling is illustrated by descriptions of a very large jet lifted 3D turbulent hydrogen flame with direct numerical simulation and 3D large eddy simulations of practical gas burner combustion devices.

  6. Combustion of high-sulfur coal and anthracite wastes in a rotary kiln combustor with an advanced internal air distributor

    SciTech Connect

    Cobb, J.T. Jr. ); Ahn, Y.K. ); Angelo, J.F. )

    1990-01-01

    Fluid bed combustors have received extensive testing with both high-sulfur coal and anthracite wastes. Rotary kilns are effective and popular devices for waste combustion. The Angelo Rotary Furnace{trademark} has been developed to improve the operation of rotary pyrolyzer/combustor systems through enhanced air distribution, which in this process is defined as staged, swirled combustion air injection. Fourteen of these new furnaces have been installed worldwide. Two units in Thailand, designed for rice hull feed with occasional lignite feed, have been recently started up. An older unit in Pennsylvania is being upgraded with a new, more advanced air distribution system for a series of tests this fall in which inexpensive high-sulfur coal and anthracite wastes will be fired with limestone. The purposes of these tests are to determine the burning characteristics of these two fuels in this system, to discover the Ca/S ratios necessary for operation of a rotary kiln combusting these fuels, and to observe the gas-borne emissions from the furnace. An extensive preliminary design study will be performed on a commercial installation for combustion of anthracite wastes. 14 refs., 5 figs., 1 tab.

  7. Combustion synthesis of advanced materials. [using in-situ infiltration technique

    NASA Technical Reports Server (NTRS)

    Moore, J. J.; Feng, H. J.; Perkins, N.; Readey, D. W.

    1992-01-01

    The combustion synthesis of ceramic-metal composites using an in-situ liquid infiltration technique is described. The effect of varying the reactants and their stoichiometry to provide a range of reactant and product species i.e. solids, liquids and gases, with varying physical properties e.g. thermal conductivity, on the microstructure and morphology of synthesized products is also described. Alternatively, conducting the combustion synthesis reaction in a reactive gas environment is also discussed, in which advantages can be gained from the synergistic effects of combustion synthesis and vapor phase transport. In each case, the effect of the presence or absence of gravity (density) driven fluid flow and vapor transport is discussed as is the potential for producing new and perhaps unique materials by conducting these SHS reactions under microgravity conditions.

  8. Recent advances in the use of synchrotron radiation for the analysis of coal combustion products

    SciTech Connect

    Manowitz, B.

    1995-11-01

    Two major coal combustion problems are the formation and build-up of slag deposits on heat transfer surfaces and the production and control of toxic species in coal combustion emissions. The use of synchrotron radiation for the analysis of coal combustion products can play a role in the better understanding of both these phenomena. An understanding of the chemical composition of such slags under boiler operating conditions and as a function of the mineral composition of various coals is one ultimate goal of this program. The principal constituents in the ash of many coals are the oxides of Si, Al, Fe, Ca, K, S, and Na. The analytical method required must be able to determine the functional forms of all these elements both in coal and in coal ash at elevated temperatures. One unique way of conducting these analyses is by x-ray spectroscopy.

  9. ADVANCED MONITORING TO IMPROVE COMBUSTION TURBINE/COMBINED CYCLE CT/(CC) RELIABILITY, AVAILABILITY AND MAINTAINABILITY (RAM)

    SciTech Connect

    Leonard Angello

    2004-09-30

    Power generators are concerned with the maintenance costs associated with the advanced turbines that they are purchasing. Since these machines do not have fully established operation and maintenance (O&M) track records, power generators face financial risk due to uncertain future maintenance costs. This risk is of particular concern, as the electricity industry transitions to a competitive business environment in which unexpected O&M costs cannot be passed through to consumers. These concerns have accelerated the need for intelligent software-based diagnostic systems that can monitor the health of a combustion turbine in real time and provide valuable information on the machine's performance to its owner/operators. EPRI, Impact Technologies, Boyce Engineering, and Progress Energy have teamed to develop a suite of intelligent software tools integrated with a diagnostic monitoring platform that will, in real time, interpret data to assess the ''total health'' of combustion turbines. The Combustion Turbine Health Management System (CTHM) will consist of a series of dynamic link library (DLL) programs residing on a diagnostic monitoring platform that accepts turbine health data from existing monitoring instrumentation. The CTHM system will be a significant improvement over currently available techniques for turbine monitoring and diagnostics. CTHM will interpret sensor and instrument outputs, correlate them to a machine's condition, provide interpretative analyses, project servicing intervals, and estimate remaining component life. In addition, it will enable real-time anomaly detection and diagnostics of performance and mechanical faults, enabling power producers to more accurately predict critical component remaining useful life and turbine degradation.

  10. ADVANCED MONITORING TO IMPROVE COMBUSTION TURBINE/COMBINED CYCLE CT/(CC) RELIABILITY, AVAILABILITY AND MAINTAINABILITY (RAM)

    SciTech Connect

    Leonard Angello

    2004-03-31

    Power generators are concerned with the maintenance costs associated with the advanced turbines that they are purchasing. Since these machines do not have fully established operation and maintenance (O&M) track records, power generators face financial risk due to uncertain future maintenance costs. This risk is of particular concern, as the electricity industry transitions to a competitive business environment in which unexpected O&M costs cannot be passed through to consumers. These concerns have accelerated the need for intelligent software-based diagnostic systems that can monitor the health of a combustion turbine in real time and provide valuable information on the machine's performance to its owner/operators. EPRI, Impact Technologies, Boyce Engineering, and Progress Energy have teamed to develop a suite of intelligent software tools integrated with a diagnostic monitoring platform that will, in real time, interpret data to assess the ''total health'' of combustion turbines. The Combustion Turbine Health Management System (CTHM) will consist of a series of dynamic link library (DLL) programs residing on a diagnostic monitoring platform that accepts turbine health data from existing monitoring instrumentation. The CTHM system will be a significant improvement over currently available techniques for turbine monitoring and diagnostics. CTHM will interpret sensor and instrument outputs, correlate them to a machine's condition, provide interpretative analyses, project servicing intervals, and estimate remaining component life. In addition, it will enable real-time anomaly detection and diagnostics of performance and mechanical faults, enabling power producers to more accurately predict critical component remaining useful life and turbine degradation.

  11. Combustion Fundamentals Research

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Increased emphasis is placed on fundamental and generic research at Lewis Research Center with less systems development efforts. This is especially true in combustion research, where the study of combustion fundamentals has grown significantly in order to better address the perceived long term technical needs of the aerospace industry. The main thrusts for this combustion fundamentals program area are as follows: analytical models of combustion processes, model verification experiments, fundamental combustion experiments, and advanced numeric techniques.

  12. Coal combustion science

    SciTech Connect

    Hardesty, D.R.; Baxter, L.L.; Fletcher, T.H.; Mitchell, R.E.

    1990-11-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project. Specific tasks include: coal devolatilization, coal char combustion, and fate of mineral matter during coal combustion. 91 refs., 40 figs., 9 tabs.

  13. Investigation of heat transfer and combustion in the advanced fluidized bed combustor (FBC)

    SciTech Connect

    Dr. Seong W. Lee

    1998-10-01

    The objective of this project is to predict the heat transfer and combustion performance in newly-designed fluidized bed combustor (FBC) and to provide the design guide lines and innovative concept for small-scale boiler and furnace. The major accomplishments are summarized.

  14. Advancements in Dual-Pump Broadband CARS for Supersonic Combustion Measurements

    NASA Astrophysics Data System (ADS)

    Tedder, Sarah Augusta Umberger

    Space- and time-resolved measurements of temperature and species mole fractions of nitrogen, oxygen, and hydrogen were obtained with a dual-pump coherent anti-Stokes Raman spectroscopy (CARS) system in hydrogen-fueled supersonic combustion free jet flows. These measurements were taken to provide time-resolved fluid properties of turbulent supersonic combustion for use in the creation and verification of computational fluid dynamic (CFD) models. CFD models of turbulent supersonic combustion flow currently facilitate the design of air- breathing supersonic combustion ramjet (scramjet) engines. Measurements were made in supersonic axi-symmetric free jets of two scales. First, the measurement system was tested in a laboratory environment using a laboratory-scale burner (˜10 mm at nozzle exit). The flow structures of the laboratory-burner were too small to be resolved with the CARS measurements volume, but the composition and temperature of the jet allowed the performance of the system to be evaluated. Subsequently, the system was tested in a burner that was approximately 6 times larger, whose length scales are better resolved by the CARS measurement volume. During both these measurements, weaknesses of the CARS system, such as sensitivity to vibrations and beam steering and inability to measure temperature or species concentrations in hydrogen fuel injection regions were identified. Solutions were then implemented in improved CARS systems. One of these improved systems is a dual-pump broadband CARS technique called, Width Increased Dual-pump Enhanced CARS (WIDECARS). The two lowest rotational energy levels of hydrogen detectable by WIDECARS are H2 S(3) and H2 S(4). The detection of these lines gives the system the capability to measure temperature and species concentrations in regions of the flow containing pure hydrogen fuel at room temperature. WIDECARS is also designed for measurements of all the major species (except water) in supersonic combustion flows fueled

  15. Advancements in Dual-Pump Broadband CARS for Supersonic Combustion Measurements

    NASA Technical Reports Server (NTRS)

    Tedder, Sarah Augusta Umberger

    2010-01-01

    Space- and time-resolved measurements of temperature and species mole fractions of nitrogen, oxygen, and hydrogen were obtained with a dual-pump coherent anti-Stokes Raman spectroscopy (CARS) system in hydrogen-fueled supersonic combustion free jet flows. These measurements were taken to provide time-resolved fluid properties of turbulent supersonic combustion for use in the creation and verification of computational fluid dynamic (CFD) models. CFD models of turbulent supersonic combustion flow currently facilitate the design of air-breathing supersonic combustion ramjet (scramjet) engines. Measurements were made in supersonic axi-symmetric free jets of two scales. First, the measurement system was tested in a laboratory environment using a laboratory-scale burner (approx.10 mm at nozzle exit). The flow structures of the laboratory-burner were too small to be resolved with the CARS measurements volume, but the composition and temperature of the jet allowed the performance of the system to be evaluated. Subsequently, the system was tested in a burner that was approximately 6 times larger, whose length scales are better resolved by the CARS measurement volume. During both these measurements, weaknesses of the CARS system, such as sensitivity to vibrations and beam steering and inability to measure temperature or species concentrations in hydrogen fuel injection regions were indentified. Solutions were then implemented in improved CARS systems. One of these improved systems is a dual-pump broadband CARS technique called, Width Increased Dual-pump Enhanced CARS (WIDECARS). The two lowest rotational energy levels of hydrogen detectable by WIDECARS are H2 S(3) and H2 S(4). The detection of these lines gives the system the capability to measure temperature and species concentrations in regions of the flow containing pure hydrogen fuel at room temperature. WIDECARS is also designed for measurements of all the major species (except water) in supersonic combustion flows

  16. Investigation of the performance of the General Electric ADVANCE positron emission tomograph in 3D mode

    SciTech Connect

    Lewellen, T.K.; Kohlmyer, S.G.; Miyaoka, R.S.; Kaplan, M.S.; Stearns, C.W.; Schubert, S.F.

    1996-08-01

    Performance measurements of the General Electric ADVANCE Positron Emission Tomograph operating with the septa retracted (3D mode) were made. All reconstructions were performed with the GE ADVANCE 3D package. Performance tests were carried out with: the NEMA phantoms; a 3D Hoffman phantom; a Data Spectrum torso phantom with lung and cardiac inserts; and the Utah 3D evaluation phantom. Data collected included: transaxial and axial resolution, uniformity, recovery coefficients, count rate performance, dead time accuracy, and effect of scatter correction.

  17. Learning guide for the terminal configured vehicle advanced guidance and control system mode select panel

    NASA Technical Reports Server (NTRS)

    Anderson, M. A.; Callahan, R.

    1981-01-01

    This learning guide is designed to assist pilots in taking the PLATO presimulator training course on the advanced guidance and control system mode select panel. The learning guide is divided into five sections. The first section, the introduction, presents the course goals, prerequisites, definition of PLATO activities, and a suggested approach to completing the course. The remaining four sections present the purpose, learning activities and summary of each lesson of the AGCS PLATO course, which consists of (1) AGCS introduction; (2) lower order modes; (3) higher order modes; and (4) an arrival route exercise.

  18. Technology requirements for advanced earth-orbital transportation systems, dual-mode propulsion

    NASA Technical Reports Server (NTRS)

    Haefeli, R. C.; Littler, E. G.; Hurley, J. B.; Winter, M. G.

    1977-01-01

    The application of dual-mode propulsion concepts to fully reusable single-stage-to-orbit (SSTO) vehicles is discussed. Dual-mode propulsion uses main rocket engines that consume hydrocarbon fuels as well as liquid hydrogen fuel. Liquid oxygen is used as the oxidizer. These engine concepts were integrated into transportation vehicle designs capable of vertical takeoff, delivering a payload to earth orbit, and return to earth with a horizontal landing. Benefits of these vehicles were assessed and compared with vehicles using single-mode propulsion (liquid hydrogen and oxygen engines). Technology requirements for such advanced transportation systems were identified. Figures of merit, including life-cycle cost savings and research costs, were derived for dual-mode technology programs, and were used for assessments of potential benefits of proposed technology activities. Dual-mode propulsion concepts display potential for significant cost and performance benefits when applied to SSTO vehicles.

  19. Fabrication of High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner for Advanced Rocket Engines

    NASA Technical Reports Server (NTRS)

    Bhat, Biliyar N.; Greene, Sandra E.; Singh, Jogender

    2016-01-01

    This paper describes the process development for fabricating a high thermal conductivity NARloy-Z-Diamond composite (NARloy-Z-D) combustion chamber liner for application in advanced rocket engines. The fabrication process is challenging and this paper presents some details of these challenges and approaches used to address them. Prior research conducted at NASA-MSFC and Penn State had shown that NARloy-Z-40%D composite material has significantly higher thermal conductivity than the state of the art NARloy-Z alloy. Furthermore, NARloy-Z-40 %D is much lighter than NARloy-Z. These attributes help to improve the performance of the advanced rocket engines. Increased thermal conductivity will directly translate into increased turbopump power, increased chamber pressure for improved thrust and specific impulse. Early work on NARloy-Z-D composites used the Field Assisted Sintering Technology (FAST, Ref. 1, 2) for fabricating discs. NARloy-Z-D composites containing 10, 20 and 40vol% of high thermal conductivity diamond powder were investigated. Thermal conductivity (TC) data. TC increased with increasing diamond content and showed 50% improvement over pure copper at 40vol% diamond. This composition was selected for fabricating the combustion chamber liner using the FAST technique.

  20. Advances in Turbulent Combustion Dynamics Simulations in Bluff-Body Stabilized Flames-Body Stabilized Flames

    DTIC Science & Technology

    2015-11-30

    stationary combustion and lean blow-out, an improved version of the Linear Eddy Model approach is used, while in the case of thermo-acoustic...instabilities, the effect of boundary conditions on the predictions are studied. The improved version couples the Linear Eddy Model with the full-set of... improved Linear Eddy Model approach is applied to predict the flame properties inside the Volvo rig and it is shown to over-predict the flame

  1. Advanced Laser-Based Techniques for Gas-Phase Diagnostics in Combustion and Aerospace Engineering.

    PubMed

    Ehn, Andreas; Zhu, Jiajian; Li, Xuesong; Kiefer, Johannes

    2017-03-01

    Gaining information of species, temperature, and velocity distributions in turbulent combustion and high-speed reactive flows is challenging, particularly for conducting measurements without influencing the experimental object itself. The use of optical and spectroscopic techniques, and in particular laser-based diagnostics, has shown outstanding abilities for performing non-intrusive in situ diagnostics. The development of instrumentation, such as robust lasers with high pulse energy, ultra-short pulse duration, and high repetition rate along with digitized cameras exhibiting high sensitivity, large dynamic range, and frame rates on the order of MHz, has opened up for temporally and spatially resolved volumetric measurements of extreme dynamics and complexities. The aim of this article is to present selected important laser-based techniques for gas-phase diagnostics focusing on their applications in combustion and aerospace engineering. Applicable laser-based techniques for investigations of turbulent flows and combustion such as planar laser-induced fluorescence, Raman and Rayleigh scattering, coherent anti-Stokes Raman scattering, laser-induced grating scattering, particle image velocimetry, laser Doppler anemometry, and tomographic imaging are reviewed and described with some background physics. In addition, demands on instrumentation are further discussed to give insight in the possibilities that are offered by laser flow diagnostics.

  2. Advanced Start of Combustion Sensor Phases I and II-A: Feasibility Demonstration, Design and Optimization

    SciTech Connect

    Chad Smutzer

    2010-01-31

    Homogeneous Compressed Charge Ignition (HCCI) has elevated the need for Start of Combustion (SOC) sensors. HCCI engines have been the exciting focus of engine research recently, primarily because HCCI offers higher thermal efficiency than the conventional Spark Ignition (SI) engines and significantly lower NOx and soot emissions than conventional Compression Ignition (CI) engines, and could be fuel neutral. HCCI has the potential to unify all the internal combustion engine technology to achieve the high-efficiency, low-emission goal. However, these advantages do not come easy. It is well known that the problems encountered with HCCI combustion center on the difficulty of controlling the Start of Combustion. TIAX has an SOC sensor under development which has shown promise. In previous work, including a DOE-sponsored SBIR project, TIAX has developed an accelerometer-based method which was able to determine SOC within a few degrees crank angle for a range of operating conditions. A signal processing protocol allows reconstruction of the combustion pressure event signal imbedded in the background engine vibration recorded by the accelerometer. From this reconstructed pressure trace, an algorithm locates the SOC. This SOC sensor approach is nonintrusive, rugged, and is particularly robust when the pressure event is strong relative to background engine vibration (at medium to high engine load). Phase I of this project refined the previously developed technology with an engine-generic and robust algorithm. The objective of the Phase I research was to answer two fundamental questions: Can the accelerometer-based SOC sensor provide adequate SOC event capture to control an HCCI engine in a feedback loop? And, will the sensor system meet cost, durability, and software efficiency (speed) targets? Based upon the results, the answer to both questions was 'YES'. The objective of Phase II-A was to complete the parameter optimization of the SOC sensor prototype in order to reach a

  3. Advanced optical diagnostics of multiphase combustion flow field using OH planar laser-induced fluorescence

    NASA Astrophysics Data System (ADS)

    Cho, Kevin Young-jin

    High-repetition-rate (5 kHz, 10 kHz) OH planar laser induced fluorescence (PLIF) was used to investigate the combustion of liquid, gelled, and solid propellants. For the liquid monomethyl hydrazine (MMH) droplet combustion experiment in N2O/N2 using 5 kHz OH PLIF and visible imaging system, the OH profile and the droplet diameter were measured. The N2O partial pressure was varied by 20% and 40%, and the total pressure was varied by 103, 172, 276, 414, 552 kPa. The OH location indicated that the oxidation flame front is between the visible dual flame fronts. The results showed thicker flame sheet and higher burning rate for increased N2O concentration for a given pressure. The burning rate increased with increased pressure at 20% partial pressure N2O, and the burning rate decreased with increased pressure at 40% partial pressure N2O. This work provides experimental data for validating chemical kinetics models. For the gelled droplet combustion experiment using a 5 kHz OH PLIF system, speeds and locations of fuel jets emanating from the burning gelled droplets were quantified for the first time. MMH was gelled with organic gellant HPC at 3 wt.% and 6 wt.%, and burned in air at 35, 103, 172, 276, and 414 kPa. Different types of interaction of vapor jets and flame front were distinguished for the first time. For high jet speed, local extinction of the flame was observed. By analyzing the jet speed statistics, it was concluded that pressure and jet speed had an inverse relationship and gellant concentration and jet speed had a direct relationship. This work provides more fundamental insight into the physics of gelled fuel droplet combustion. A 3D OH PLIF system was assembled and demonstrated using a 10 kHz OH PLIF system and a galvanometric scanning mirror. This is the first time that a reacting flow field was imaged with a 3D optical technique using OH PLIF. A 3D scan time of 1 ms was achieved, with ten slices generated per sweep with 1000 Hz scan rate. Alternatively

  4. ADVANCED MONITORING TO IMPROVE COMBUSTION TURBINE/COMBINED CYCLE CT/(CC) RELIABILITY, AVAILABILITY AND MAINTAINABILITY (RAM)

    SciTech Connect

    Leonard Angello

    2003-09-30

    Power generators are concerned with the maintenance costs associated with the advanced turbines that they are purchasing. Since these machines do not have fully established operation and maintenance (O&M) track records, power generators face financial risk due to uncertain future maintenance costs. This risk is of particular concern, as the electricity industry transitions to a competitive business environment in which unexpected O&M costs cannot be passed through to consumers. These concerns have accelerated the need for intelligent software-based diagnostic systems that can monitor the health of a combustion turbine in real time and provide valuable information on the machine's performance to its owner/operators. Such systems would interpret sensor and instrument outputs, correlate them to the machine's condition, provide interpretative analyses, forward projections of servicing intervals, estimate remaining component life, and identify faults. EPRI, Impact Technologies, Boyce Engineering, and Progress Energy have teamed to develop a suite of intelligent software tools integrated with a diagnostic monitoring platform that will, in real time, interpret data to assess the ''total health'' of combustion turbines. The Combustion Turbine Health Management System (CTHM) will consist of a series of dynamic link library (DLL) programs residing on a diagnostic monitoring platform that accepts turbine health data from existing monitoring instrumentation. The CTHM system will be a significant improvement over currently available techniques for turbine monitoring and diagnostics. CTHM will interpret sensor and instrument outputs, correlate them to a machine's condition, provide interpretative analyses, project servicing intervals, and estimate remaining component life. In addition, it will enable real-time anomaly detection and diagnostics of performance and mechanical faults, enabling power producers to more accurately predict critical component remaining useful life and

  5. Advanced distribution, switching, and conversion technology for fluids/combustion facility electric power control

    NASA Astrophysics Data System (ADS)

    Poljak, Mark D.; Soltis, James V.; Fox, David A.

    1997-01-01

    The Electrical Power Control Unit (EPCU) under development for use in the Fluids/Combustion Facility (FCF) on International Space Station (ISS) is the precursor of modular power distribution and conversion concepts for future high power and small spacecraft applications. The EPCU is built from modular, current limiting Flexible Remote Power Controllers (FRPCs) and paralleled power converters packaged into a common orbital replacement unit. Multiple EPCUs are combined at the next higher level of integration to form the three-rack FCF Electrical Power System (EPS). This modular building block approach allows for the quick development of expandable power systems tailored to customer needs.

  6. Analytical investigation of thermal barrier coatings for advanced power generation combustion turbines

    NASA Technical Reports Server (NTRS)

    Amos, D. J.

    1977-01-01

    An analytical evaluation was conducted to determine quantitatively the improvement potential in cycle efficiency and cost of electricity made possible by the introduction of thermal barrier coatings to power generation combustion turbine systems. The thermal barrier system, a metallic bond coat and yttria stabilized zirconia outer layer applied by plasma spray techniques, acts as a heat insulator to provide substantial metal temperature reductions below that of the exposed thermal barrier surface. The study results show the thermal barrier to be a potentially attractive means for improving performance and reducing cost of electricity for the simple, recuperated, and combined cycles evaluated.

  7. INVESTIGATION OF HEAT TRANSFER AND COMBUSTION IN THE ADVANCED FLUIDIZED BED COMBUSTOR (FBC)

    SciTech Connect

    Dr. Seong W. Lee

    1998-04-01

    This technical report summarizes the research conducted and progress achieved during the period from January 1, 1998 to March 31, 1998. The systematic combustion tests were conducted to investigate the thermal performance and heat transfer effect of the exploratory hot model. The different ratios of the top to the bottom secondary air flow rate were chosen to study the effect of the secondary air flow rate. The test results indicated that the secondary air flow rate was a very sensitive factor to the combustion temperature profile. The heat transfer coefficients were changed along the combustor height. Numerical simulation was continued to determine the pressure profiles and temperature profiles in the hot combustor model. The pressure change at the bottom is greater than that of the top region because of a large amount of primary air input. The higher pressure zone is formed where the secondary air flows into the center region of the combustor. The high temperature zone of the bottom section is located at the fuel injector nozzle outlet. The lower temperature profiles were near the combustor wall because the cooling effect of the heat exchanger. The center temperature of the combustor at the upper secondary air nozzles is higher than that at the lower secondary air nozzles.

  8. Advanced radiation techniques for inspection of diesel engine combustion chamber materials components. Final report

    SciTech Connect

    1995-10-09

    Heavy duty truck engines must meet stringent life cycle cost and regulatory requirements. Meeting these requirements has resulted in convergence on 4-stroke 6-in-line, turbocharged, and after-cooled engines with direct-injection combustion systems. These engines provide much higher efficiencies (42%, fuel consumption 200 g/kW-hr) than automotive engines (31%, fuel consumption 270 g/kW-hr), but at higher initial cost. Significant near-term diesel engine improvements are necessary and are spurred by continuing competitive, Middle - East oil problems and Congressional legislation. As a result of these trends and pressures, Caterpillar has been actively pursuing a low-fuel consumption engine research program with emphasis on product quality through process control and product inspection. The goal of this project is to combine the nondestructive evaluation and computational resources and expertise available at LLNL with the diesel engine and manufacturing expertise of the Caterpillar Corporation to develop in-process monitoring and inspection techniques for diesel engine combustion chamber components and materials. Early development of these techniques will assure the optimization of the manufacturing process by design/inspection interface. The transition from the development stage to the manufacturing stage requires a both a thorough understanding of the processes and a way of verifying conformance to process standards. NDE is one of the essential tools in accomplishing both elements and in this project will be integrated with Caterpillar`s technological and manufacturing expertise to accomplish the project goals.

  9. Comparison of ash behavior of different fuels in fluidised bed combustion using advanced fuel analysis and global equilibrium calculations

    SciTech Connect

    Zevenhoven-Onderwater, M.; Blomquist, J.P.; Skrifvars, B.J.; Backman, R.; Hupa, M.

    1999-07-01

    The behavior of different ashes is predicted by means of a combination of an advanced fuel analysis and global equilibrium calculations. In order to cover a broad spectrum of fuels a coal, a peat, a forest residue and Salix (i.e. willow) are studied. The latter was taken with and without soil contamination, i.e. with a high and low content of silica , respectively. It is shown that mineral matter in fossil and biomass fuels can be present in the matrix of the fuel itself or as included minerals. Using an advanced fuel analysis, i.e. a fractionation method, this mineral content can be divided into four fractions. The first fraction mainly contains those metal ions, that can be leached out of the fuel by water and mainly contains alkali sulfates, carbonates and chlorides. The second fraction mainly consists of those ions leached out by ammonium acetate and covers those ions, that are connected to the organic matrix. The third fraction contains the metals leached out by hydrochloric acid and contains earth alkali carbonates and sulfates as well as pyrites. The rest fraction contains those minerals, that are not leached out by any of the above mentioned solvents, such as silicates. A global equilibrium analysis is used to predict the thermal and chemical behavior of the combined first and second fractions and of the combined third and rest fractions under pressurized and/or atmospheric combustion conditions. Results of both the fuel analysis and the global equilibrium analysis are discussed and practical implications for combustion processes are pointed out.

  10. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide emissions from coal-fired boilers

    SciTech Connect

    Sorge, J.N.; Menzies, B.; Smouse, S.M.; Stallings, J.W.

    1995-09-01

    Technology project demonstrating advanced wall-fired combustion techniques for the reduction of nitrogen oxide NOx emissions from coal-fired boilers. The primary objective of the demonstration is to determine the long-term NOx reduction performance of advanced overfire air (AOFA), low NOx burners (LNB), and advanced digital control/optimization methodologies applied in a stepwise fashion to a 500 MW boiler. The focus of this paper is to report (1) on the installation of three on-line carbon-in-ash monitors and (2) the design and results to date from the advanced digital control/optimization phase of the project.

  11. Advanced coal-fueled industrial cogeneration gas turbine system -- combustion development

    SciTech Connect

    LeCren, R.T.

    1994-06-01

    This topical report summarizes the combustor development work accomplished under the subject contract. The objective was to develop a combustion system for the Solar 4MW Type H Centaur gas turbine generator set which was to be used to demonstrate the economic, technical and environmental feasibility of a direct coal-fueled gas turbine in a 100 hour proof-of-concept test. This program started with a design configuration derived during the CSC program. The design went through the following evolution: CSC design which had some known shortcomings, redesigned CSC now designated as the Two Stage Slagging Combustor (TSSC), improved TSSC with the PRIS evaluated in the IBSTF, and full scale design. Supporting and complimentary activities included computer modelling, flow visualization, slag removal, SO{sub x} removal, fuel injector development and fuel properties evaluation. Three combustor rigs were utilized: the TSSC, the IBSTF and the full scale rig at Peoria. The TSSC rig, which was 1/10th scale of the proposed system, consisted of a primary and secondary zone and was used to develop the primary zone performance and to evaluate SO{sub x} and slag removal and fuel properties variations. The IBSTF rig which included all the components of the proposed system was also 1/10th scale except for the particulate removal system which was about 1/30th scale. This rig was used to verify combustor performance data obtained on the TSSC and to develop the PRIS and the particulate removal system. The full scale rig initially included the primary and secondary zones and was later modified to incorporate the PRIS. The purpose of the full scale testing was to verify the scale up calculations and to provide a combustion system for the proof-of-concept engine test that was initially planned in the program.

  12. Observation of Energetic Particle Driven Modes Relevant to Advanced Tokamak Regimes

    SciTech Connect

    R. Nazikian; B. Alper; H.L. Berk; D. Borba; C. Boswell; R.V. Budny; K.H. Burrell; C.Z. Cheng; E.J. Doyle; E. Edlund; R.J. Fonck; A. Fukuyama; N.N. Gorelenkov; C.M. Greenfield; D.J. Gupta; M. Ishikawa; R.J. Jayakumar; G.J. Kramer; Y. Kusama; R.J. La Haye; G.R. McKee; W.A. Peebles; S.D. Pinches; M. Porkolab; J. Rapp; T.L. Rhodes; S.E. Sharapov; K. Shinohara; J.A. Snipes; W.M. Solomon; E.J. Strait; M. Takechi; M.A. Van Zeeland; W.P. West; K.L. Wong; S. Wukitch; L. Zeng

    2004-10-21

    Measurements of high-frequency oscillations in JET [Joint European Torus], JT-60U, Alcator C-Mod, DIII-D, and TFTR [Tokamak Fusion Test Reactor] plasmas are contributing to a new understanding of fast ion-driven instabilities relevant to Advanced Tokamak (AT) regimes. A model based on the transition from a cylindrical-like frequency-chirping mode to the Toroidal Alfven Eigenmode (TAE) has successfully encompassed many of the characteristics seen in experiments. In a surprising development, the use of internal density fluctuation diagnostics has revealed many more modes than has been detected on edge magnetic probes. A corollary discovery is the observation of modes excited by fast particles traveling well below the Alfven velocity. These observations open up new opportunities for investigating a ''sea of Alfven Eigenmodes'' in present-scale experiments, and highlight the need for core fluctuation and fast ion measurements in a future burning-plasma experiment.

  13. Advanced Interval Type-2 Fuzzy Sliding Mode Control for Robot Manipulator

    PubMed Central

    Hwang, Ji-Hwan; Kang, Young-Chang

    2017-01-01

    In this paper, advanced interval type-2 fuzzy sliding mode control (AIT2FSMC) for robot manipulator is proposed. The proposed AIT2FSMC is a combination of interval type-2 fuzzy system and sliding mode control. For resembling a feedback linearization (FL) control law, interval type-2 fuzzy system is designed. For compensating the approximation error between the FL control law and interval type-2 fuzzy system, sliding mode controller is designed, respectively. The tuning algorithms are derived in the sense of Lyapunov stability theorem. Two-link rigid robot manipulator with nonlinearity is used to test and the simulation results are presented to show the effectiveness of the proposed method that can control unknown system well. PMID:28280505

  14. Numerical Study of Equilibrium, Stability, and Advanced Resistive Wall Mode Feedback Algorithms on KSTAR

    NASA Astrophysics Data System (ADS)

    Katsuro-Hopkins, Oksana; Sabbagh, S. A.; Bialek, J. M.; Park, H. K.; Kim, J. Y.; You, K.-I.; Glasser, A. H.; Lao, L. L.

    2007-11-01

    Stability to ideal MHD kink/ballooning modes and the resistive wall mode (RWM) is investigated for the KSTAR tokamak. Free-boundary equilibria that comply with magnetic field coil current constraints are computed for monotonic and reversed shear safety factor profiles and H-mode tokamak pressure profiles. Advanced tokamak operation at moderate to low plasma internal inductance shows that a factor of two improvement in the plasma beta limit over the no-wall beta limit is possible for toroidal mode number of unity. The KSTAR conducting structure, passive stabilizers, and in-vessel control coils are modeled by the VALEN-3D code and the active RWM stabilization performance of the device is evaluated using both standard and advanced feedback algorithms. Steady-state power and voltage requirements for the system are estimated based on the expected noise on the RWM sensor signals. Using NSTX experimental RWM sensors noise data as input, a reduced VALEN state-space LQG controller is designed to realistically assess KSTAR stabilization system performance.

  15. Research Study to Identify Technology Requirements for Advanced Earth-Orbital Transportation Systems, Dual-Mode Propulsion

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The results of a study of dual mode propulsion concepts applied to advanced earth orbital transportation systems using reuseable single stage to orbit vehicle concepts were summarized. Both series burn and parallel burn modes of propulsion were analyzed for vertical takeoff, horizontal landing vehicles based on accelerated technology goals. A major study objective was to assess the merits of dual mode main propulsion concepts compared to single mode concepts for carrying payloads of Space Shuttle type to orbit.

  16. Implications of Low Particulate Matter Emissions on System Fuel Efficiency for High Efficiency Clean Combustion

    SciTech Connect

    Parks, II, James E; Prikhodko, Vitaly Y

    2009-01-01

    Advanced diesel combustion regimes such as High Efficiency Clean Combustion (HECC) offer the benefits of reduced engine out NOX and particulate matter (PM) emissions. Lower PM emissions during advanced combustion reduce the demand on diesel particulate filters (DPFs) and can, thereby, reduce the fuel penalty associated with DPF regeneration. In this study, a SiC DPF was loaded and regenerated on a 1.7-liter 4-cylinder diesel engine operated in conventional and advanced combustion modes at different speed and load conditions. A diesel oxidation catalyst (DOC) and a lean NOX trap (LNT) were also installed in the exhaust stream. Five steady-state speed and load conditions were weighted to estimate Federal Test Procedure (FTP) fuel efficiency. The DPF was loaded using lean-rich cycling with frequencies that resulted in similar levels of NOX emissions downstream of the LNT. The pressure drop across the DPF was measured at a standard point (1500 rpm, 5.0 bar) before and after loading, and a P rise rate was determined for comparison between conventional and advanced combustion modes. Higher PM emissions in conventional combustion resulted in a higher rate of backpressure rise across the DPF at all of the load points leading to more frequent DPF regenerations and higher fuel penalty. The fuel penalty during conventional combustion was 4.2% compared with 3.1% for a mixture of conventional and advanced modes.

  17. Advances in Turbulent Combustion Dynamics Simulations in Bluff-Body Stabilized Flames

    NASA Astrophysics Data System (ADS)

    Tovar, Jonathan Michael

    This work examines the three main aspects of bluff-body stabilized flames: stationary combustion, lean blow-out, and thermo-acoustic instabilities. For the cases of stationary combustion and lean blow-out, an improved version of the Linear Eddy Model approach is used, while in the case of thermo-acoustic instabilities, the effect of boundary conditions on the predictions are studied. The improved version couples the Linear Eddy Model with the full-set of resolved scale Large Eddy Simulation equations for continuity, momentum, energy, and species transport. In traditional implementations the species equations are generally solved using a Lagrangian method which has some significant limitations. The novelty in this work is that the Eulerian species concentration equations are solved at the resolved scale and the Linear Eddy Model is strictly used to close the species production term. In this work, the improved Linear Eddy Model approach is applied to predict the flame properties inside the Volvo rig and it is shown to over-predict the flame temperature and normalized velocity when compared to experimental data using a premixed single step global propane reaction with an equivalence ratio of 0.65. The model is also applied to predict lean blow-out and is shown to predict a stable flame at an equivalence ratio of 0.5 when experiments achieve flame extinction at an equivalence ratio of 0.55. The improved Linear Eddy Model is, however, shown to be closer to experimental data than a comparable reactive flow simulation that uses laminar closure of the species source terms. The thermo-acoustic analysis is performed on a combustor rig designed at the Air Force Research Laboratory. The analysis is performed using a premixed single step global methane reaction for laminar reactive flow and shows that imposing a non-physical boundary condition at the rig exhaust will result in the suppression of acoustic content inside the domain and can alter the temperature contours in non

  18. DOE Project 18546, AOP Task 1.1, Fuel Effects on Advanced Combustion Engines

    SciTech Connect

    Bunting, Bruce G; Bunce, Michael

    2012-01-01

    Research in 2011 was focused on diesel range fuels and diesel combustion and fuels evaluated in 2011 included a series of oxygenated biofuels fuels from University of Maine, oxygenated fuel compounds representing materials which could be made from sewage, oxygenated marine diesel fuels for low emissions, and a new series of FACE fuel surrogates and FACE fuels with detailed exhaust chemistry and particulate size measurements. Fuels obtained in late 2011, which will be evaluated in 2012, include a series of oil shale derived fuels from PNNL, green diesel fuel (hydrotreated vegetable oil) from UOP, University of Maine cellulosic biofuel (levulene), and pyrolysis derived fuels from UOP pyrolysis oil, upgraded at University of Georgia. We were able to demonstrate, through a project with University of Wisconsin, that a hybrid strategy for fuel surrogates provided both accurate and rapid CFD combustion modeling for diesel HCCI. In this strategy, high molecular weight compounds are used to more accurately represent physical processes and smaller molecular weight compounds are used for chemistry to speed chemical calculations. We conducted a small collaboration with sp3H, a French company developing an on-board fuel quality sensor based on near infrared analysis to determine how to use fuel property and chemistry information for engine control. We were able to show that selected outputs from the sensor correlated to both fuel properties and to engine performance. This collaboration leveraged our past statistical analysis work and further work will be done as opportunity permits. We conducted blending experiments to determine characteristics of ethanol blends based on the gasoline characteristics used for blending. Results indicate that much of the octane benefits gained by high level ethanol blending can be negated by use of low octane gasoline blend stocks, as allowed by ASTM D5798. This may limit ability to optimize engines for improved efficiency with ethanol fuels

  19. Investigation of heat transfer and combustion in the advanced fluidized bed combustor (FBC)

    SciTech Connect

    Lee, S.W.

    1999-09-01

    This technical report summarizes the research conducted and progress achieved during the period from April 1, 1998 to June 30, 1998. The numerical simulation was continued to determine the concentration distribution of the gas species, heat flux and heat transfer coefficients in the hot combustor model. The different gas concentration profiles showed the gas mixing characteristics along the combustor height. The center zone of the combustor has a relatively high methane mass concentration. The injection of secondary air squeezes the uprising flue gas and methane that causes the fuel-lean zone near the secondary air nozzles. The carbon dioxide concentration increased with the increasing of the combustor height. The peak concentration of oxygen remains at the combustor wall because of the secondary injection. The heat flux on the wall of the upper chamber is much higher than that of the lower chamber. It is believed that the heat flux is affected by the designed strong swirl and secondary air injection. The heat transfer coefficient changes along the combustor height were also affected by the multiple secondary air injection. The numerical simulation results could verify the predictions of the experimental results. It is a quite similar trend of the heat transfer coefficient changes based on the combustion test results.

  20. Advanced Materials and Manufacturing for Low-Cost, High-Performance Liquid Rocket Combustion Chambers

    NASA Technical Reports Server (NTRS)

    Williams, Brian E.; Arrieta, Victor M.

    2013-01-01

    A document describes the low-cost manufacturing of C103 niobium alloy combustion chambers, and the use of a high-temperature, oxidation-resistant coating that is superior to the standard silicide coating. The manufacturing process involved low-temperature spray deposition of C103 on removable plastic mandrels produced by rapid prototyping. Thin, vapor-deposited platinum-indium coatings were shown to substantially improve oxidation resistance relative to the standard silicide coating. Development of different low-cost plastic thrust chamber mandrel materials and prototyping processes (selective laser sintering and stereolithography) yielded mandrels with good dimensional accuracy (within a couple of mils) for this stage of development. The feasibility of using the kinetic metallization cold-spray process for fabrication of free-standing C1O3 thrusters on removable plastic mandrels was also demonstrated. The ambient and elevated temperature mechanical properties of the material were shown to be reasonably good relative to conventionally processed C103, but the greatest potential benefit is that coldsprayed chambers require minimal post-process machining, resulting in substantially lower machining and material costs. The platinum-iridium coating was shown to provide greatly increased oxidation resistance over the silicide when evaluated through oxyacetylene torch testing to as high as 300 F (= 150 C). The iridium component minimizes reaction with the niobium alloy chamber at high temperatures, and provides the high-temperature oxidation resistance needed at the throat.

  1. Hydrocarbon Fouling of SCR during PCCI combustion

    SciTech Connect

    Prikhodko, Vitaly Y; Pihl, Josh A; Lewis Sr, Samuel Arthur; Parks, II, James E

    2012-01-01

    The combination of advanced combustion with advanced selective catalytic reduction (SCR) catalyst formulations was studied in the work presented here to determine the impact of the unique hydrocarbon (HC) emissions from premixed charge compression ignition (PCCI) combustion on SCR performance. Catalyst core samples cut from full size commercial Fe- and Cu-zeolite SCR catalysts were exposed to a slipstream of raw engine exhaust from a 1.9-liter 4-cylinder diesel engine operating in conventional and PCCI combustion modes. The zeolites which form the basis of these catalysts are different with the Cu-based catalyst made on a chabazite zeolite which las smaller pore structures relative to the Fe-based catalyst. Subsequent to exposure, bench flow reactor characterization of performance and hydrocarbon release and oxidation enabled evaluation of overall impacts from the engine exhaust. The Fe-zeolite NOX conversion efficiency was significantly degraded, especially at low temperatures (<250 C), after the catalyst was exposed to the raw engine exhaust. The degradation of the Fe-zeolite performance was similar for both combustion modes. The Cu-zeolite showed better tolerance to HC fouling at low temperatures compared to the Fe-zeolite but PCCI exhaust had a more significant impact than the exhaust from conventional combustion on the NOX conversion efficiency. Furthermore, chemical analysis of the hydrocarbons trapped on the SCR cores was conducted to better determine chemistry specific effects.

  2. Development of Computational Approaches for Simulation and Advanced Controls for Hybrid Combustion-Gasification Chemical Looping

    SciTech Connect

    Joshi, Abhinaya; Lou, Xinsheng; Neuschaefer, Carl; Chaudry, Majid; Quinn, Joseph

    2012-07-31

    This document provides the results of the project through September 2009. The Phase I project has recently been extended from September 2009 to March 2011. The project extension will begin work on Chemical Looping (CL) Prototype modeling and advanced control design exploration in preparation for a scale-up phase. The results to date include: successful development of dual loop chemical looping process models and dynamic simulation software tools, development and test of several advanced control concepts and applications for Chemical Looping transport control and investigation of several sensor concepts and establishment of two feasible sensor candidates recommended for further prototype development and controls integration. There are three sections in this summary and conclusions. Section 1 presents the project scope and objectives. Section 2 highlights the detailed accomplishments by project task area. Section 3 provides conclusions to date and recommendations for future work.

  3. Spectrally Analyzed Embedded Infrared Fiber Optic Diagnostic of Advanced Composite Propellant Combustion

    DTIC Science & Technology

    2006-05-31

    observations, XM39. This nitramine composite propellant is 76 per cent RDX with most of the balance made up by the binder cellulose acetate butyrate and the...13 Figure 7 Predicted Model Spectrum for Pure Decomposition Gas at 6 atm with a 0.3 cm Absorption Path Length...program of in situ diagnostics and laboratory experiments has led to more advanced models of the gas phase processes in the dark zone and secondary flame

  4. Intelligent Control via Wireless Sensor Networks for Advanced Coal Combustion Systems

    SciTech Connect

    Aman Behal; Sunil Kumar; Goodarz Ahmadi

    2007-08-05

    Numerical Modeling of Solid Gas Flow, System Identification for purposes of modeling and control, and Wireless Sensor and Actor Network design were pursued as part of this project. Time series input-output data was obtained from NETL's Morgantown CFB facility courtesy of Dr. Lawrence Shadle. It was run through a nonlinear kernel estimator and nonparametric models were obtained for the system. Linear and first-order nonlinear kernels were then utilized to obtain a state-space description of the system. Neural networks were trained that performed better at capturing the plant dynamics. It is possible to use these networks to find a plant model and the inversion of this model can be used to control the system. These models allow one to compare with physics based models whose parameters can then be determined by comparing them against the available data based model. On a parallel track, Dr. Kumar designed an energy-efficient and reliable transport protocol for wireless sensor and actor networks, where the sensors could be different types of wireless sensors used in CFB based coal combustion systems and actors are more powerful wireless nodes to set up a communication network while avoiding the data congestion. Dr. Ahmadi's group studied gas solid flow in a duct. It was seen that particle concentration clearly shows a preferential distribution. The particles strongly interact with the turbulence eddies and are concentrated in narrow bands that are evolving with time. It is believed that observed preferential concentration is due to the fact that these particles are flung out of eddies by centrifugal force.

  5. Optical investigation of the combustion behaviour inside the engine operating in HCCI mode and using alternative diesel fuel

    SciTech Connect

    Mancaruso, E.; Vaglieco, B.M.

    2010-04-15

    In order to understand the effect of both the new homogeneous charge compression ignition (HCCI) combustion process and the use of biofuel, optical measurements were carried out into a transparent CR diesel engine. Rape seed methyl ester was used and tests with several injection pressures were performed. OH and HCO radical were detected and their evolutions were analyzed during the whole combustion. Moreover, soot concentration was measured by means the two colour pyrometry method. The reduction of particulate emission with biodiesel as compared to the diesel fuel was noted. Moreover, this effect resulted higher increasing the injection pressure. In the case of RME the oxidation of soot depends mainly from O{sub 2} content of fuel and OH is responsible of the NO formation in the chamber as it was observed for NO{sub x} exhaust emission. Moreover, it was investigated the evolution of HCO and CO into the cylinder. HCO was detected at the start of combustion. During the combustion, HCO oxidizes due to the increasing temperature and it produces CO. Both fuels have similar trend, the highest concentrations are detected for low injection pressure. This effect is more evident for the RME fuel. (author)

  6. Edge localized mode characteristics during edge localized mode mitigation by supersonic molecular beam injection in Korea Superconducting Tokamak Advanced Research

    SciTech Connect

    Lee, H. Y.; Hong, J. H.; Jang, J. H.; Park, J. S.; Choe, Wonho; Hahn, S. H.; Bak, J. G.; Lee, J. H.; Ko, W. H.; Lee, K. D.; Lee, S. H.; Lee, H. H.; Juhn, J.-W.; Kim, H. S.; Yoon, S. W.; Han, H.; Ghim, Y.-C.

    2015-12-15

    It has been reported that supersonic molecular beam injection (SMBI) is an effective means of edge localized mode (ELM) mitigation. This paper newly reports the changes in the ELM, plasma profiles, and fluctuation characteristics during ELM mitigation by SMBI in Korea Superconducting Tokamak Advanced Research. During the mitigated ELM phase, the ELM frequency increased by a factor of 2–3 and the ELM size, which was estimated from the D{sub α} amplitude, the fractional changes in the plasma-stored energy and the line-averaged electron density, and divertor heat flux during an ELM burst, decreased by a factor of 0.34–0.43. Reductions in the electron and ion temperatures rather than in the electron density were observed during the mitigated ELM phase. In the natural ELM phase, frequency chirping of the plasma fluctuations was observed before the ELM bursts; however, the ELM bursts occurred without changes in the plasma fluctuation frequency in the mitigated ELM phase.

  7. A Combustion Research Facility for Testing Advanced Materials for Space Applications

    NASA Technical Reports Server (NTRS)

    Bur, Michael J.

    2003-01-01

    The test facility presented herein uses a groundbased rocket combustor to test the durability of new ceramic composite and metallic materials in a rocket engine thermal environment. A gaseous H2/02 rocket combustor (essentially a ground-based rocket engine) is used to generate a high temperature/high heat flux environment to which advanced ceramic and/or metallic materials are exposed. These materials can either be an integral part of the combustor (nozzle, thrust chamber etc) or can be mounted downstream of the combustor in the combustor exhaust plume. The test materials can be uncooled, water cooled or cooled with gaseous hydrogen.

  8. Towards next-generation label-free biosensors: recent advances in whispering gallery mode sensors.

    PubMed

    Kim, Eugene; Baaske, Martin D; Vollmer, Frank

    2017-03-29

    Whispering gallery mode biosensors have been widely exploited over the past decade to study molecular interactions by virtue of their high sensitivity and applicability in real-time kinetic analysis without the requirement to label. There have been immense research efforts made for advancing the instrumentation as well as the design of detection assays, with the common goal of progressing towards real-world sensing applications. We therefore review a set of recent developments made in this field and discuss the requirements that whispering gallery mode label-free sensors need to fulfill for making a real world impact outside of the laboratory. These requirements are directly related to the challenges that these sensors face, and the methods proposed to overcome them are discussed. Moving forward, we provide the future prospects and the potential impact of this technology.

  9. An analysis of markets for small-scale, advanced coal-combustion technology in Spain, Italy, and Turkey

    SciTech Connect

    Placet, M.; Gerry, P.A.; Kenski, D.M.; Kern, D.M.; Nehring, J.L.; Szpunar, C.B.

    1989-09-01

    This report discusses the examination of potential overseas markets for using small-scale, US-developed, advanced coal-combustion technologies (ACTs). In previous work, member countries of the Organization for Economic Cooperation and Development (OECD) were rated on their potential for using ACTs through a comprehensive screening methodology. The three most promising OECD markets were found to be Spain, Italy, and Turkey. This report provides in-depth analyses of these three selected countries. First, it addresses changes in the European Community with particular reference to the 1992 restructuring and its potential effect on the energy situation in Europe, specifically in the three subject countries. It presents individual country studies that examine demographics, economics, building infrastructures, and energy-related factors. Potential niches for ACTs are explored for each country through regional analyses. Marketing channels, strategies, and the trading environments in each country are also discussed. The information gathered indicates that Turkey is a most promising market, Spain is a fairly promising market, and Italy appears to be a somewhat limited market for US ACTs. 76 refs., 16 figs., 14 tabs.

  10. A Mode Propagation Database Suitable for Code Validation Utilizing the NASA Glenn Advanced Noise Control Fan and Artificial Sources

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.

    2014-01-01

    The NASA Glenn Research Center's Advanced Noise Control Fan (ANCF) was developed in the early 1990s to provide a convenient test bed to measure and understand fan-generated acoustics, duct propagation, and radiation to the farfield. A series of tests were performed primarily for the use of code validation and tool validation. Rotating Rake mode measurements were acquired for parametric sets of: (1) mode blockage, (2) liner insertion loss, (3) short ducts, and (4) mode reflection.

  11. A Mode Propagation Database Suitable for Code Validation Utilizing the NASA Glenn Advanced Noise Control Fan and Artificial Sources

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.

    2014-01-01

    The NASA Glenn Research Center's Advanced Noise Control Fan (ANCF) was developed in the early 1990s to provide a convenient test bed to measure and understand fan-generated acoustics, duct propagation, and radiation to the farfield. A series of tests were performed primarily for the use of code validation and tool validation. Rotating Rake mode measurements were acquired for parametric sets of: (i) mode blockage, (ii) liner insertion loss, (iii) short ducts, and (iv) mode reflection.

  12. An ultrafast optics undergraduate advanced laboratory with a mode-locked fiber laser

    NASA Astrophysics Data System (ADS)

    Schaffer, Andrew; Fredrick, Connor; Hoyt, Chad; Jones, Jason

    2015-05-01

    We describe an ultrafast optics undergraduate advanced laboratory comprising a mode-locked erbium fiber laser, auto-correlation measurements, and an external, free-space parallel grating dispersion compensation apparatus. The simple design of the stretched pulse laser uses nonlinear polarization rotation mode-locking to produce pulses at a repetition rate of 55 MHz and average power of 5.5 mW. Interferometric and intensity auto-correlation measurements are made using a Michelson interferometer that takes advantage of the two-photon nonlinear response of a common silicon photodiode for the second order correlation between 1550 nm laser pulses. After a pre-amplifier and compression, pulse widths as narrow as 108 fs are measured at 17 mW average power. A detailed parts list includes previously owned and common components used by the telecommunications industry, which may decrease the cost of the lab to within reach of many undergraduate and graduate departments. We also describe progress toward a relatively low-cost optical frequency comb advanced laboratory. NSF EIR #1208930.

  13. Recent Advances In Structural Vibration And Failure Mode Control In Mainland China: Theory, Experiments And Applications

    SciTech Connect

    Li Hui; Ou Jinping

    2008-07-08

    A number of researchers have been focused on structural vibration control in the past three decades over the world and fruit achievements have been made. This paper introduces the recent advances in structural vibration control including passive, active and semiactive control in mainland China. Additionally, the co-author extends the structural vibration control to failure mode control. The research on the failure mode control is also involved in this paper. For passive control, this paper introduces full scale tests of buckling-restrained braces conducted to investigate the performance of the dampers and the second-editor of the Code of Seismic Design for Buildings. For active control, this paper introduces the HMD system for wind-induced vibration control of the Guangzhou TV tower. For semiactive control, the smart damping devices, algorithms for semi-active control, design methods and applications of semi-active control for structures are introduced in this paper. The failure mode control for bridges is also introduced.

  14. Performance experiments with alternative advanced teleoperator control modes for a simulated solar maximum satellite repair

    NASA Technical Reports Server (NTRS)

    Das, H.; Zak, H.; Kim, W. S.; Bejczy, A. K.; Schenker, P. S.

    1992-01-01

    Experiments are described which were conducted at the JPL Advanced Teleoperator Lab to demonstrate and evaluate the effectiveness of various teleoperator control modes in the performance of a simulated Solar Max Satellite Repair (SMSR) task. THe SMSR was selected as a test because it is very rich in performance capability requirements and it actually has been performed by two EVA astronauts in the Space Shuttle Bay in 1984. The main subtasks are: thermal blanket removal; installation of a hinge attachment for electrical panel opening; opening of electrical panel; removal of electrical connectors; relining of cable bundles; replacement of electrical panel; securing parts and cables; re-mate electrical connectors; closing of electrical panel; and reinstating thermal blanket. The current performance experiments are limited to thermal blanket cutting, electrical panel unbolting and handling electrical bundles and connectors. In one formal experiment even different control modes were applied to the unbolting and reinsertion of electrical panel screws subtasks. The seven control modes are alternative combinations of manual position and rate control with force feedback and remote compliance referenced to force-torque sensor information. Force-torque sensor and end effector position data and task completion times were recorded for analysis and quantification of operator performance.

  15. Industrial Combustion Technology Roadmap: A Technology Roadmap by and for the Industrial Combustion Community (1999)

    SciTech Connect

    none,

    1999-04-01

    Combustion system users and manufacturers joined forces in 1999 to develop the Industrial Combustion Technology Roadmap. The roadmap outlines R&D priorities for developing advanced, highly efficient combustion systems that U.S. industry will require in the future.

  16. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide emissions from coal-fired boilers

    SciTech Connect

    Sorge, J.N.; Larrimore, C.L.; Slatsky, M.D.; Menzies, W.R.; Smouse, S.M.; Stallings, J.W.

    1997-12-31

    This paper discusses the technical progress of a US Department of Energy Innovative Clean Coal Technology project demonstrating advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The primary objectives of the demonstration is to determine the long-term NOx reduction performance of advanced overfire air (AOFA), low NOx burners (LNB), and advanced digital control optimization methodologies applied in a stepwise fashion to a 500 MW boiler. The focus of this paper is to report (1) on the installation of three on-line carbon-in-ash monitors and (2) the design and results to date from the advanced digital control/optimization phase of the project.

  17. TOXIC SUBSTANCES FROM COAL COMBUSTION--A COMPREHENSIVE ASSESSMENT, PHASE II: ELEMENT MODES OF OCCURRENCE FOR THE OHIO 5/6/7, WYODAK AND NORTH DAKOTA COAL SAMPLES

    SciTech Connect

    Allan Kolker; Stanley J. Mroczkowski; Curtis A. Palmer; Kristen O. Dennen; Robert B. Finkelman; John H. Bullock Jr.

    2002-05-30

    This study reports on the second phase (Phase II) of USGS research activities in support of DOE contract DE-AC22-95PC95101 ''Toxic Substances From Coal Combustion--A Comprehensive Assessment'', funded under DOE Interagency Agreement DE-AI22-95PC95145. The purpose of the study was to provide a quantitative and semi-quantitative characterization of the modes of occurrence of trace elements in coal samples investigated under Phase II, including (1) Ohio 5/6/7, an Ohio bituminous coal sample blended from the No.5, No.6, and No.7 beds; (2) North Dakota, a lignite sample from the Falkirk Mine, Underwood, ND, and (3) Wyodak, a sub-bituminous coal sample from the Cordero Mine, Gillette, WY. Samples from these coal beds were selected for their range in rank and commercial applicability. Results of this research provide basic information on the distribution of elements in Phase II coal samples, information needed for development of a commercial predictive model for trace-element behavior during coal combustion.

  18. Formation of Ti5Si3 by Combustion Synthesis in a Self-Propagating Mode: Experimental Study and Numerical Simulation

    NASA Astrophysics Data System (ADS)

    Yeh, C. L.; Chou, C. C.; Hwang, P. W.

    2016-09-01

    Titanium silicide (Ti5Si3) was fabricated by self-propagating high-temperature synthesis (SHS) from the elemental powder compact. With the increase of sample density from 50 to 60% TMD, experiments showed that the flame-front velocity increased from 28 to 50 mm/s and combustion temperature from 1,580 to 1,700°C. Based on their dependence, the activation energy of the synthesis reaction, Ea=193 kJ/mol, was deduced. By numerical simulation of combustion wave kinetics, the Arrhenius factor of the rate function, K0=3×109 s-1, was determined for the 5Ti + 3Si reaction system. The effect of sample compaction density on the SHS process was correlated to the variation of the effective thermal conductivity (keff) of the powder compact. The ratio of keff/kbulk=0.02-0.05 was numerically obtained for the 5Ti + 3Si samples with 50-60% TMD and well validated by the experimental data.

  19. Atmospheric fluidized bed combustion advanced system concepts applicable to small industrial and commercial markets. Topical report, Level 2

    SciTech Connect

    Ake, T.R.; Dixit, V.B.; Mongeon, R.K.

    1992-09-01

    As part of an overall strategy to promote FBC coal combustion and to improve the marketability of the eastern coals, the US Department of Energy`s Morgantown Energy Research Center awarded a three level contract to Riley Stoker Corporation to develop advanced Multi Solids Fluidized Bed (MSFB) boiler designs. The first level of this contract targeted the small package boiler (10,000--50,000 lb/hr steam) and industrial size boiler (75,000--150,000 lb/hr steam) markets. Two representative sizes, 30,000 lb/hr and 110,000 lb/hr of steam, were selected for the two categories for a detailed technical and economic evaluation. Technically, both the designs showed promise, however, the advanced industrial design was favored on economic considerations. It was thus selected for further study in the second level of the contract. Results of this Level-2 effort, presented in this report, consisted of testing the design concept in Riley`s 4.4 MBtu/hr pilot MSFB facility located at Riley Research Center in Worcester, Mass. The design and economics of the proof of concept facility developed in Level-1 of the contract were then revised in accordance with the findings of the pilot test program. A host site for commercial demonstration in Level-3 of the contract was also secured. It was determined that co-firing coal in combination with paper de-inking sludge will broaden the applicability of the design beyond conventional markets. International Paper (IP), the largest paper company in the world, is willing to participate in this part of the program. IP has offered its Hammermill operation at Lockhaven, Pa, site of a future paper de-inking plant, for the proof of concept installation. This plant will go in operation in 1994. It is recommended that METC proceed to the commercial demonstration of the design developed. The approach necessary to satisfy the needs of the customer while meeting the objectives of this program is presented along with a recommended plan of action.

  20. Advances in quantitative nanoscale subsurface imaging by mode-synthesizing atomic force microscopy

    SciTech Connect

    Vitry, P.; Bourillot, E.; Plassard, C.; Lacroute, Y.; Lesniewska, E.; Tetard, L.

    2014-08-04

    This paper reports on advances toward quantitative non-destructive nanoscale subsurface investigation of a nanofabricated sample based on mode synthesizing atomic force microscopy with heterodyne detection, addressing the need to correlate the role of actuation frequencies of the probe f{sub p} and the sample f{sub s} with depth resolution for 3D tomography reconstruction. Here, by developing a simple model and validating the approach experimentally through the study of the nanofabricated calibration depth samples consisting of buried metallic patterns, we demonstrate avenues for quantitative nanoscale subsurface imaging. Our findings enable the reconstruction of the sample depth profile and allow high fidelity resolution of the buried nanostructures. Non-destructive quantitative nanoscale subsurface imaging offers great promise in the study of the structures and properties of complex systems at the nanoscale.

  1. A New Method for Shear Stabilization of Advanced Tokamak Reactors via Mode Converted Ion Bernstein Waves*

    NASA Astrophysics Data System (ADS)

    Sund, Richard; Scharer, John

    2002-11-01

    We examine a new method for generating sheared flows in advanced tokamak D-T reactors with the goal of creating and controlling internal transport barriers. Ion-Bernstein waves (IBWs) have the recognized capacity to create internal transport barriers through sheared plasma flows resulting from ion absorption. Under reactor conditions, the IBW can be generated by mode conversion of a fast magnetosonic wave incident from the high-field side (HFS) on the second harmonic resonance of a minority hydrogen component, with near 100200 MHz) minimizes parasitic absorption and permits the converted IBW to approach the fifth tritium harmonic. It also facilitates compact antennas and feeds, and efficient fast wave launch. Placement of the 5T absorption layer on the HFS is advantageous for shear production. The scheme is applicable to reactors with aspect ratio < 3 such that the conversion and absorption layers are both on the high field side of the magnetic axis. Various factors (adequate separation of the mode conversion layer from the magnetic axis, concentration of the fast wave near the midplane, large machine size, and plasma elongation) minimize poloidal field effects in the conversion zone and permit a slab analysis. We use a 1-D full-wave code to analyze the conversion and absorption. A 2-D ray-tracing code incorporating poloidal magnetic fields is used to follow the IBW for various equilibria. Within this analysis a weak bean shape appears most favorable. This is an attractive scheme for future advanced tokamak reactors. *Research supported by the Univ. of Wisconsin, Madison

  2. Treatment of dairy manure using the microwave enhanced advanced oxidation process under a continuous mode operation.

    PubMed

    Yu, Yang; Lo, Ing W; Liao, Ping H; Lo, Kwang V

    2010-11-01

    The microwave enhanced advanced oxidation process (MW/H(2)O(2)-AOP) was used to treat dairy manure for solubilization of nutrients and organic matters. This study investigated the effectiveness of the MW/H(2)O(2)-AOP under a continuous mode of operation, and compared the results to those of batch operations. The main factors affecting solubilization by the MW/H(2)O(2)-AOP were heating temperature and hydrogen peroxide dosage. Soluble chemical oxygen demand (SCOD) and volatile fatty acids (VFA) increased with an increase of microwave (MW) heating temperature; very high concentrations were obtained at 90°C. Insignificant amounts of ammonia and reducing sugars were released in all runs. An acidic pH condition was required for phosphorus solubilisation from dairy manure. The best yield was obtained at 90°C with an acid dosage of 1.0 %; about 92 % of total phosphorus and 90 % of total chemical oxygen demand were in the soluble forms. The MW/H(2)O(2)-AOP operated in a continuous operation mode showed pronounced synergistic effects between hydrogen peroxide and microwave irradiation when compared to a batch system under similar operating conditions, resulting in much better yields.

  3. Progress towards top-up mode operations at the Advanced Photon Source

    SciTech Connect

    Emery, L.; Borland, M.

    1999-10-26

    The Advanced Photon Source (APS) is a 7-GeV, third-generation synchrotron radiation source. To provide a more stable beam for users, in September 1998 the authors began commissioning a new operating mode called top-up. In this mode, the beam current does not decay but is maintained at a high level using frequent injection, while photon shutters are open and photon beams are delivered to users. The exhaustive analysis for top-up safety will be reviewed as well as the hardware and software required for top-up operation. Operational experience so far includes testing aspects of top-up injection, delivering beam to X-ray users for a few hours with fractional current stability of 0.001, and routinely providing beam to users by refilling the ring to 100 mA every 12 hours with shutters open. Top-up performance issues encountered are short-lived orbit and emittance transients during the injection event, which appear in user experiments as X-ray beam brightness dips. Planned system modifications to reduce these beam transients are described. The main operational issue left for continuous top-up injection will then be sharing the injector system with other operations.

  4. Magnetohydrodynamic modes analysis and control of Fusion Advanced Studies Torus high-current scenarios

    SciTech Connect

    Villone, F.; Mastrostefano, S.; Calabrò, G.; Vlad, G.; Crisanti, F.; Fusco, V.; Marchiori, G.; Bolzonella, T.; Marrelli, L.; Martin, P.; Liu, Y. Q.

    2014-08-15

    One of the main FAST (Fusion Advanced Studies Torus) goals is to have a flexible experiment capable to test tools and scenarios for safe and reliable tokamak operation, in order to support ITER and help the final DEMO design. In particular, in this paper, we focus on operation close to a possible border of stability related to low-q operation. To this purpose, a new FAST scenario has then been designed at I{sub p} = 10 MA, B{sub T} = 8.5 T, q{sub 95} ≈ 2.3. Transport simulations, carried out by using the code JETTO and the first principle transport model GLF23, indicate that, under these conditions, FAST could achieve an equivalent Q ≈ 3.5. FAST will be equipped with a set of internal active coils for feedback control, which will produce magnetic perturbation with toroidal number n = 1 or n = 2. Magnetohydrodynamic (MHD) mode analysis and feedback control simulations performed with the codes MARS, MARS-F, CarMa (both assuming the presence of a perfect conductive wall and using the exact 3D resistive wall structure) show the possibility of the FAST conductive structures to stabilize n = 1 ideal modes. This leaves therefore room for active mitigation of the resistive mode (down to a characteristic time of 1 ms) for safety purposes, i.e., to avoid dangerous MHD-driven plasma disruption, when working close to the machine limits and magnetic and kinetic energy density not far from reactor values.

  5. 180 MW demonstration of advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO sub x ) emissions from coal-fired boilers

    SciTech Connect

    Not Available

    1991-01-01

    ABB CE's Low NOx Bulk Furnace Staging (LNBFS) System and Low NOx Concentric Firing System (LNCFS) are demonstrated in stepwise fashion. These systems incorporate the concept of advanced overfire air (AOFA), clustered coal nozzles, and offset air. A complete description of the installed technologies is provided in the following section. The primary objective of the Plant Lansing Smith demonstration is to determine the long-term effects of commercially available tangentially-fired low NOx combustion technologies on NOx emissions and boiler performance. Short-term tests of each technology are also being performed to provide engineering information about emissions and performance trends. A target of achieving fifty percent NOx reduction using combustion modifications has been established for the project.

  6. Depletion-mode carrier-plasma optical modulator in zero-change advanced CMOS.

    PubMed

    Shainline, Jeffrey M; Orcutt, Jason S; Wade, Mark T; Nammari, Kareem; Moss, Benjamin; Georgas, Michael; Sun, Chen; Ram, Rajeev J; Stojanović, Vladimir; Popović, Miloš A

    2013-08-01

    We demonstrate the first (to the best of our knowledge) depletion-mode carrier-plasma optical modulator fabricated in a standard advanced complementary metal-oxide-semiconductor (CMOS) logic process (45 nm node SOI CMOS) with no process modifications. The zero-change CMOS photonics approach enables this device to be monolithically integrated into state-of-the-art microprocessors and advanced electronics. Because these processes support lateral p-n junctions but not efficient ridge waveguides, we accommodate these constraints with a new type of resonant modulator. It is based on a hybrid microring/disk cavity formed entirely in the sub-90 nm thick monocrystalline silicon transistor body layer. Electrical contact of both polarities is made along the inner radius of the multimode ring cavity via an array of silicon spokes. The spokes connect to p and n regions formed using transistor well implants, which form radially extending lateral junctions that provide index modulation. We show 5 Gbps data modulation at 1265 nm wavelength with 5.2 dB extinction ratio and an estimated 40 fJ/bit energy consumption. Broad thermal tuning is demonstrated across 3.2 THz (18 nm) with an efficiency of 291 GHz/mW. A single postprocessing step to remove the silicon handle wafer was necessary to support low-loss optical confinement in the device layer. This modulator is an important step toward monolithically integrated CMOS photonic interconnects.

  7. Trends in the spin combustion of thermites

    SciTech Connect

    Dvoryankin, A.V.; Merzhanov, A.G.; Strunina, A.G.

    1982-09-01

    This article presents results on the main laws of spin combustion for thermite compositions. Examines the combustion in various thermite systems with various degrees of component dilution with reaction products in order to choose the objects. Discusses effects of external factors, effects of system parameters, and temperature distribution in spin combustion. Finds that oscillatory combustion (synchronous pulsation in the combustion rate at all points on the front) and spin modes (spiral displacement of a luminous focus) are separated by a combustion mode in the form of a set of luminous points moving in a random fashion over the combustion front; the low-calorie spin mode is sensitive to shift in the general heat balance in either sense during the combustion; and in the spin mode, the combustion is substantially influenced by the topology of the surface.

  8. APFBC repowering could help meet Kyoto Protocol CO{sub 2} reduction goals[Advanced Pressurized Fluidized Bed Combustion

    SciTech Connect

    Weinstein, R.E.; Tonnemacher, G.C.

    1999-07-01

    The Clinton Administration signed the 1997 Kyoto Protocol agreement that would limit US greenhouse gas emissions, of which carbon dioxide (CO{sub 2}) is the most significant. While the Kyoto Protocol has not yet been submitted to the Senate for ratification, in the past, there have been few proposed environmental actions that had continued and wide-spread attention of the press and environmental activists that did not eventually lead to regulation. Since the Kyoto Protocol might lead to future regulation, its implications need investigation by the power industry. Limiting CO{sub 2} emissions affects the ability of the US to generate reliable, low cost electricity, and has tremendous potential impact on electric generating companies with a significant investment in coal-fired generation, and on their customers. This paper explores the implications of reducing coal plant CO{sub 2} by various amounts. The amount of reduction for the US that is proposed in the Kyoto Protocol is huge. The Kyoto Protocol would commit the US to reduce its CO{sub 2} emissions to 7% below 1990 levels. Since 1990, there has been significant growth in US population and the US economy driving carbon emissions 34% higher by year 2010. That means CO{sub 2} would have to be reduced by 30.9%, which is extremely difficult to accomplish. The paper tells why. There are, however, coal-based technologies that should be available in time to make significant reductions in coal-plant CO{sub 2} emissions. Th paper focuses on one plant repowering method that can reduce CO{sub 2} per kWh by 25%, advanced circulating pressurized fluidized bed combustion combined cycle (APFBC) technology, based on results from a recent APFBC repowering concept evaluation of the Carolina Power and Light Company's (CP and L) L.V. Sutton steam station. The replacement of the existing 50-year base of power generating units needed to meet proposed Kyoto Protocol CO{sub 2} reduction commitments would be a massive undertaking. It is

  9. Chemical Kinetic Models for HCCI and Diesel Combustion

    SciTech Connect

    Pitz, W J; Westbrook, C K; Mehl, M; Sarathy, S M

    2010-11-15

    Predictive engine simulation models are needed to make rapid progress towards DOE's goals of increasing combustion engine efficiency and reducing pollutant emissions. These engine simulation models require chemical kinetic submodels to allow the prediction of the effect of fuel composition on engine performance and emissions. Chemical kinetic models for conventional and next-generation transportation fuels need to be developed so that engine simulation tools can predict fuel effects. The objectives are to: (1) Develop detailed chemical kinetic models for fuel components used in surrogate fuels for diesel and HCCI engines; (2) Develop surrogate fuel models to represent real fuels and model low temperature combustion strategies in HCCI and diesel engines that lead to low emissions and high efficiency; and (3) Characterize the role of fuel composition on low temperature combustion modes of advanced combustion engines.

  10. Light Duty Efficient, Clean Combustion

    SciTech Connect

    Stanton, Donald W.

    2011-06-03

    Cummins has successfully completed the Light Duty Efficient Clean Combustion (LDECC) cooperative program with DoE. This program was established in 2007 in support of the Department of Energy’s Vehicles Technologies Advanced Combustion and Emissions Control initiative to remove critical barriers to the commercialization of advanced, high efficiency, emissions compliant internal combustion (IC) engines for light duty vehicles. Work in this area expanded the fundamental knowledge of engine combustion to new regimes and advanced the knowledge of fuel requirements for these diesel engines to realize their full potential. All of our objectives were met with fuel efficiency improvement targets exceeded.

  11. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, second quarter 1994, April 1994--June 1994

    SciTech Connect

    1995-09-01

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NOx combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NOx reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NOx burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NOx reductions of each technology and evaluate the effects of those reductions on other combustion parameters. Results are described.

  12. Equipment concept design and development plans for microgravity science and applications research on space station: Combustion tunnel, laser diagnostic system, advanced modular furnace, integrated electronics laboratory

    NASA Technical Reports Server (NTRS)

    Uhran, M. L.; Youngblood, W. W.; Georgekutty, T.; Fiske, M. R.; Wear, W. O.

    1986-01-01

    Taking advantage of the microgravity environment of space NASA has initiated the preliminary design of a permanently manned space station that will support technological advances in process science and stimulate the development of new and improved materials having applications across the commercial spectrum. Previous studies have been performed to define from the researcher's perspective, the requirements for laboratory equipment to accommodate microgravity experiments on the space station. Functional requirements for the identified experimental apparatus and support equipment were determined. From these hardware requirements, several items were selected for concept designs and subsequent formulation of development plans. This report documents the concept designs and development plans for two items of experiment apparatus - the Combustion Tunnel and the Advanced Modular Furnace, and two items of support equipment the Laser Diagnostic System and the Integrated Electronics Laboratory. For each concept design, key technology developments were identified that are required to enable or enhance the development of the respective hardware.

  13. Generalities on combustion instabilities

    NASA Astrophysics Data System (ADS)

    Kuentzmann, Paul

    The main manifestations of combustion instabilities are reviewed, and the specific characteristics of instabilities in solid-propellant rocket engines are analyzed, with the Minuteman III third-stage engine and the SRB engine of Titan 34 D considered as examples. The main approaches for predicting combustion instabilities are discussed, including the linear approach based on the acoustic balance, the nonlinear mode-coupling approach, and the nonlinear approach using numerical calculation. Projected directions for future research are also examined.

  14. Advanced Catalysis Technologies: Lanthanum Cerium Manganese Hexaaluminate Combustion Catalysts for Flat Plate Reactor for Compact Steam Reformers

    DTIC Science & Technology

    2008-12-01

    DEVELOPMENT OF THIN FILM CATALYSIS AND THE COMBUSTION CATALYST 1 Summary The steam reforming reaction is fast and endothermic; therefore, the rate...lean natural gas turbines in order to reduce NOx emissions to reforming catalyst to convert diesel and kerosene to hydrogen rich gases. Unlike... gas turbines, in order to reduce NOx emissions, to reforming catalyst to convert distillate fuels, such as diesel and kerosene, to hydrogen rich

  15. Dual-Mode Combustor

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J (Inventor); Dippold, Vance F (Inventor)

    2013-01-01

    A new dual-mode ramjet combustor used for operation over a wide flight Mach number range is described. Subsonic combustion mode is usable to lower flight Mach numbers than current dual-mode scramjets. High speed mode is characterized by supersonic combustion in a free-jet that traverses the subsonic combustion chamber to a variable nozzle throat. Although a variable combustor exit aperture is required, the need for fuel staging to accommodate the combustion process is eliminated. Local heating from shock-boundary-layer interactions on combustor walls is also eliminated.

  16. Recent advances in combustion flow-field imaging measurements in high-pressure liquid-fueled gas turbine combustor concepts

    NASA Astrophysics Data System (ADS)

    Locke, Randy J.; Hicks, Yolanda R.; Zaller, Michelle M.; Anderson, Robert C.

    1999-12-01

    Future gas turbine combustor designs for aerospace applications will be required to meet severe restrictions on environmentally harmful emissions. To meet the target emission reduction goals, these combustors will operate at temperatures and pressures greatly exceeding those of present day aero-powerplants. New diagnostic methods are required to provide insight into understanding the complex physical and chemical processes extant at these conditions because traditional diagnostic methods are either insufficient or incapable of providing this knowledge. At NASA Glenn Research Center (GRC), several optically accessible combustor rigs have been built which allow the implementation of a suite of optical diagnostic techniques that are capable of providing just this type of crucial information. The techniques employed in the GRC combustion research laboratory include planar laser-induced fluorescence and planar Mie scattering. Research efforts have been quite successful probing both non-reacting and reacting flowfields of many kerosene-fueled combustor and combustor subcomponent design at pressures approaching 2.0 MPa, and temperatures near 2100 K. Images that map out combustion intermediate species such as OH distribution, fuel spray patternation, and fuel to air ratio contour mapping have been obtained for many different fuel injector designs and configurations. A novel combination of multiple planar images and computational analysis allows a 3D capability that greatly enhances the evaluation of the combustion processes and flowfields examined in this study.

  17. Evaluation of advanced combustion concepts for dry NO sub x suppression with coal-derived, gaseous fuels

    NASA Technical Reports Server (NTRS)

    Beebe, K. W.; Symonds, R. A.; Notardonato, J. J.

    1982-01-01

    The emissions performance of a rich lean combustor (developed for liquid fuels) was determined for combustion of simulated coal gases ranging in heating value from 167 to 244 Btu/scf (7.0 to 10.3 MJ/NCM). The 244 Btu/scf gas is typical of the product gas from an oxygen blown gasifier, while the 167 Btu/scf gas is similar to that from an air blown gasifier. NOx performance of the rich lean combustor did not meet program goals with the 244 Btu/scf gas because of high thermal NOx, similar to levels expected from conventional lean burning combustors. The NOx emissions are attributed to inadequate fuel air mixing in the rich stage resulting from the design of the large central fuel nozzle delivering 71% of the total gas flow. NOx yield from ammonia injected into the fuel gas decreased rapidly with increasing ammonia level, and is projected to be less than 10% at NH3 levels of 0.5% or higher. NOx generation from NH3 is significant at ammonia concentrations significantly less than 0.5%. These levels may occur depending on fuel gas cleanup system design. CO emissions, combustion efficiency, smoke and other operational performance parameters were satisfactory. A test was completed with a catalytic combustor concept with petroleum distillate fuel. Reactor stage NOx emissions were low (1.4g NOx/kg fuel). CO emissions and combustion efficiency were satisfactory. Airflow split instabilities occurred which eventually led to test termination.

  18. Kinetic-MHD hybrid simulation of fishbone modes excited by fast ions on the experimental advanced superconducting tokamak (EAST)

    NASA Astrophysics Data System (ADS)

    Pei, Youbin; Xiang, Nong; Hu, Youjun; Todo, Y.; Li, Guoqiang; Shen, Wei; Xu, Liqing

    2017-03-01

    Kinetic-MagnetoHydroDynamic hybrid simulations are carried out to investigate fishbone modes excited by fast ions on the Experimental Advanced Superconducting Tokamak. The simulations use realistic equilibrium reconstructed from experiment data with the constraint of the q = 1 surface location (q is the safety factor). Anisotropic slowing down distribution is used to model the distribution of the fast ions from neutral beam injection. The resonance condition is used to identify the interaction between the fishbone mode and the fast ions, which shows that the fishbone mode is simultaneously in resonance with the bounce motion of the trapped particles and the transit motion of the passing particles. Both the passing and trapped particles are important in destabilizing the fishbone mode. The simulations show that the mode frequency chirps down as the mode reaches the nonlinear stage, during which there is a substantial flattening of the perpendicular pressure of fast ions, compared with that of the parallel pressure. For passing particles, the resonance remains within the q = 1 surface, while, for trapped particles, the resonant location moves out radially during the nonlinear evolution. In addition, parameter scanning is performed to examine the dependence of the linear frequency and growth rate of fishbones on the pressure and injection velocity of fast ions.

  19. Advanced high pressure engine study for mixed-mode vehicle applications

    NASA Technical Reports Server (NTRS)

    Luscher, W. P.; Mellish, J. A.

    1977-01-01

    High pressure liquid rocket engine design, performance, weight, envelope, and operational characteristics were evaluated for a variety of candidate engines for use in mixed-mode, single-stage-to-orbit applications. Propellant property and performance data were obtained for candidate Mode 1 fuels which included: RP-1, RJ-5, hydrazine, monomethyl-hydrazine, and methane. The common oxidizer was liquid oxygen. Oxygen, the candidate Mode 1 fuels, and hydrogen were evaluated as thrust chamber coolants. Oxygen, methane, and hydrogen were found to be the most viable cooling candidates. Water, lithium, and sodium-potassium were also evaluated as auxiliary coolant systems. Water proved to be the best of these, but the system was heavier than those systems which cooled with the engine propellants. Engine weight and envelope parametric data were established for candidate Mode 1, Mode 2, and dual-fuel engines. Delivered engine performance data were also calculated for all candidate Mode 1 and dual-fuel engines.

  20. Coal Combustion Science

    SciTech Connect

    Hardesty, D.R.; Fletcher, T.H.; Hurt, R.H.; Baxter, L.L. )

    1991-08-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency Coal Combustion Science Project. Specific tasks for this activity include: (1) coal devolatilization - the objective of this risk is to characterize the physical and chemical processes that constitute the early devolatilization phase of coal combustion as a function of coal type, heating rate, particle size and temperature, and gas phase temperature and oxidizer concentration; (2) coal char combustion -the objective of this task is to characterize the physical and chemical processes involved during coal char combustion as a function of coal type, particle size and temperature, and gas phase temperature and oxygen concentration; (3) fate of mineral matter during coal combustion - the objective of this task is to establish a quantitative understanding of the mechanisms and rates of transformation, fragmentation, and deposition of mineral matter in coal combustion environments as a function of coal type, particle size and temperature, the initial forms and distribution of mineral species in the unreacted coal, and the local gas temperature and composition.

  1. Advancing the Physics Basis of Quiescent H-mode through Exploration of ITER Relevant Parameters

    SciTech Connect

    Solomon, W. M.; Burrell, K. H.; Fenstermacher, M. E.; Garofalo, A. M.; Grierson, B. A.; Loarte, A.; McKee, G. R.; Nazikian, R.; Snyder, B. P.

    2014-09-01

    Recent experiments on DIII-D have overcome a long-standing limitation in accessing quiescent H-mode (QH-mode), a high confinement state of the plasma that does not exhibit the explosive instabilities associated with edge localized modes (ELMs). In the past, QH-mode was associated with low density operation, but has now been extended to high normalized densities compatible with operation envisioned for ITER. Through the use of strong shaping, QH-mode plasmas have been maintained at high densities, both absolute (ηe ≈ 7 × 1019 m—3) and normalized Greenwald fraction (ηe/ηG > 0:7) . In these plasmas, the pedestal can evolve to very high pressures and current as the density is increased. Calculations of the pedestal height and width from the EPED model are quantitatively consistent with the experimental observed evolution with density. The comparison of the dependence of the maximum density threshold for QH-mode with plasma shape help validate the underlying theoretical peeling-ballooning models describing ELM stability. High density QH-mode operation with strong shaping has allowed stable access to a previously predicted regime of very high pedestal dubbed \\Super H-mode". In general, QH-mode is found to achieve ELM-stable operation while maintaining adequate impurity exhaust, due to the enhanced impurity transport from an edge harmonic oscillation, thought to be a saturated kink- peeling mode driven by rotation shear. In addition, the impurity confinement time is not affected by rotation, even though the energy confinement time and measured E Χ B shear is observed to increase at low toroidal rotation. Together with demonstrations of high beta, high confinement and low q95 for many energy confinement times, these results suggest QH-mode as a potentially attractive operating scenario for ITER's Q=10 mission.

  2. Cyclic Combustion Variations in Dual Fuel Partially Premixed Pilot-Ignited Natural Gas Engines

    SciTech Connect

    Srinivasan, K. K.; Krishnan, S. R.; Qi, Y.

    2012-05-09

    Dual fuel pilot ignited natural gas engines are identified as an efficient and viable alternative to conventional diesel engines. This paper examines cyclic combustion fluctuations in conventional dual fuel and in dual fuel partially premixed low temperature combustion (LTC). Conventional dual fueling with 95% (energy basis) natural gas (NG) substitution reduces NOx emissions by almost 90%t relative to straight diesel operation; however, this is accompanied by 98% increase in HC emissions, 10 percentage points reduction in fuel conversion efficiency (FCE) and 12 percentage points increase in COVimep. Dual fuel LTC is achieved by injection of a small amount of diesel fuel (2-3 percent on an energy basis) to ignite a premixed natural gas₋air mixture to attain very low NOx emissions (less than 0.2 g/kWh). Cyclic variations in both combustion modes were analyzed by observing the cyclic fluctuations in start of combustion (SOC), peak cylinder pressures (Pmax), combustion phasing (Ca50), and the separation between the diesel injection event and Ca50 (termed "relative combustion phasing" ). For conventional dual fueling, as % NG increases, Pmax decreases, SOC and Ca50 are delayed, and cyclic variations increase. For dual fuel LTC, as diesel injection timing is advanced from 20° to 60° BTDC, the relative combustion phasing is identified as an important combustion parameter along with SoC, Pmax, and CaPmax. For both combustion modes, cyclic variations were characterized by alternating slow and fast burn cycles, especially at high %NG and advanced injection timings. Finally, heat release return maps were analyzed to demonstrate thermal management strategies as an effective tool to mitigate cyclic combustion variations, especially in dual fuel LTC.

  3. Development of advanced combustion technology for medium- and high-speed natural gas engines. Final report, January 1985-February 1989

    SciTech Connect

    Snyder, W.E.

    1989-07-01

    The project investigated the several variables which influence the performance of pre-chamber equipped, lean-burn natural gas engines in general, and of the pre-chamber in particular. The effort was divided into four closely inter-related phases: Theoretical Analysis, Constant Volume Combustion (CVC) Rig Tests, Single Cylinder Engine Tests and Multi-Cylinder Engine Tests. The Theoretical Analysis was directed toward development of a computer program, called COGEN, which was then used to predict output performance trends resulting from changes to input parameters. The CVC Rig Test program was directed towards an improved understanding of the pre-chamber combustion process using high speed photography and simultaneous measurement of instantaneous pressures. Variations of pre-chamber size, throat design and air-fuel ratio were studied to guide the later engine test programs. The Single Cylinder Engine Tests were directed towards bridging the gap between the CVC Test Rig and the performance to be expected from a commercial multi-cylinder engine. Variations in pre-chamber design as well as engine compression ratio, Intake Manifold Temperature and load were investigated.

  4. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Phase 2, Overfire air tests

    SciTech Connect

    Smith, L.L.; Hooper, M.P.

    1992-07-13

    This Phase 2 Test Report summarizes the testing activities and results for the second testing phase of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The second phase demonstrates the Advanced Overfire Air (AOFA) retrofit with existing Foster Wheeler (FWEC) burners. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data supported by short-term characterization data. Ultimately a fifty percent NO{sub x} reduction target using combinations of combustion modifications has been established for this project.

  5. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO[sub x]) emissions from coal-fired boilers

    SciTech Connect

    Smith, L.L.; Hooper, M.P. )

    1992-07-13

    This Phase 2 Test Report summarizes the testing activities and results for the second testing phase of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO[sub x]) emissions from coal-fired boilers. The second phase demonstrates the Advanced Overfire Air (AOFA) retrofit with existing Foster Wheeler (FWEC) burners. The project is being conducted at Georgia Power Company's Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO[sub x] combustion equipment through the collection and analysis of long-term emissions data supported by short-term characterization data. Ultimately a fifty percent NO[sub x] reduction target using combinations of combustion modifications has been established for this project.

  6. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO[sub x]) emissions from coal-fired boilers

    SciTech Connect

    Not Available

    1992-01-01

    The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO[sub x] burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO[sub x] reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulatecharacteristics and boiler efficiency. Baseline, AOFA, and LNB without AOFA test segments have been completed. Analysis of the 94 days of LNB long-term data collected show the full-load NO[sub x] emission levels to be approximately 0.65 lb/MBtu. Flyash LOI values for the LNB configuration are approximately 8 percent at full-load. Corresponding values for the AOFA configuration are 0.94 lb/MBtu and approximately 10 percent. Abbreviated diagnostic tests for the LNB+AOFA configuration indicate that at 500 MWe, NO[sub x] emissions are approximately 0.55 lb/MBtu with corresponding flyash LOI values of approximately 11 percent. For comparison, the long-term full-load, baseline NO[sub x] emission level was approximately 1.24 lb/MBtu at 5.2 percent LOI. Comprehensive testing of the LNB+AOFA configuration will be performed when the stackparticulate emissions issue is resolved. Testing of a process optimization package on Plant Hammond Unit 4 was performed during this quarter. The software was configured to minimize NO[sub x] emissions using total combustion air flow and advanced overfire air distribution as the controlled parameters. Preliminary results from this testing indicate that this package shows promise in reducing NO[sub x] emissions while maintaining or improving other boiler performance parameters.

  7. Effects of Fusion Zone Size on Failure Modes and Performance of Advanced High Strength Steel Spot Welds

    SciTech Connect

    Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2006-04-28

    This paper examines the effects of fusion zone size on failure modes, static strength and energy absorption of resistance spot welds (RSW) of advanced high strength steels (AHSS). DP800 and TRIP800 spot welds are considered. The main failure modes for spot welds are nugget pullout and interfacial fracture. Partial interfacial fracture is also observed. The critical fusion zone sizes to ensure nugget pull-out failure mode are developed for both DP800 and TRIP800 using the limit load based analytical model and the micro-hardness measurements of the weld cross sections. Static weld strength tests using cross tension samples were performed on the joint populations with controlled fusion zone sizes. The resulted peak load and energy absorption levels associated with each failure mode were studied using statistical data analysis tools. The results in this study show that the conventional weld size of 4 t can not produce nugget pullout mode for both the DP800 and TRIP800 materials. The results also suggest that performance based spot weld acceptance criteria should be developed for different AHSS spot welds.

  8. Combustion noise

    NASA Technical Reports Server (NTRS)

    Strahle, W. C.

    1977-01-01

    A review of the subject of combustion generated noise is presented. Combustion noise is an important noise source in industrial furnaces and process heaters, turbopropulsion and gas turbine systems, flaring operations, Diesel engines, and rocket engines. The state-of-the-art in combustion noise importance, understanding, prediction and scaling is presented for these systems. The fundamentals and available theories of combustion noise are given. Controversies in the field are discussed and recommendations for future research are made.

  9. Advances in understanding quiescent H-mode plasmas in DIII-D

    SciTech Connect

    Burrell, K.H.; West, W.P.; Gohil, P.; Greenfield, C.M.; Groebner, R.J.; Hyatt, A.W.; Kaplan, D.H.; Lao, L.L.; Leonard, A.W.; Osborne, T.H.; Snyder, P.B.; Thomas, D.M.; Strait, E.J.; Doyle, E.J.; Rhodes, T.L.; Wang, G.; Zeng, L.; Austin, M.E.; Casper, T.A.; Jayakumar, R.J.

    2005-05-15

    Recent QH-mode research on DIII-D [J. L. Luxon et al., Plasma Physics and Controlled Nuclear Fusion Research 1996 (International Atomic Energy Agency, Vienna, 1987), Vol. I, p. 159] has used the peeling-ballooning modes model of edge magnetohydrodynamic stability as a working hypothesis to organize the data; several predictions of this theory are consistent with the experimental results. Current ramping results indicate that QH modes operate near the edge current limit set by peeling modes. This operating point explains why QH mode is easier to get at lower plasma currents. Power scans have shown a saturation of edge pressure with increasing power input. This allows QH-mode plasmas to remain stable to edge localized modes (ELMs) to the highest powers used in DIII-D. At present, the mechanism for this saturation is unknown; if the edge harmonic oscillation (EHO) is playing a role here, the physics is not a simple amplitude dependence. The increase in edge stability with plasma triangularity predicted by the peeling-ballooning theory is consistent with the substantial improvement in pedestal pressure achieved by changing the plasma shape from a single null divertor to a high triangularity double null. Detailed ELITE calculations for the high triangularity plasmas have demonstrated that the plasma operating point is marginally stable to peeling-ballooning modes. Comparison of ELMing, coinjected and quiescent, counterinjected discharges with the same shape, current, toroidal field, electron density, and electron temperature indicates that the edge radial electric field or the edge toroidal rotation are also playing a role in edge stability. The EHO produces electron, main ion, and impurity particle transport at the plasma edge which is more rapid than that produced by ELMs under similar conditions. The EHO also decreases the edge rotation while producing little change in the edge electron and ion temperatures. Other edge electromagnetic modes also produce particle

  10. Bioaccumulation and effects of metals and trace elements from aquatic disposal of coal combustion residues: recent advances and recommendations for further study.

    PubMed

    Rowe, Christopher L

    2014-07-01

    Advances have been made recently in assessing accumulation and effects of coal combustion residues (CCR). I provide a brief review of recent advancements, provide a tabulated summary of results of recent work, and put forth recommendations for future studies. One advancement is that mercury accumulation has begun to receive (limited) attention, whereas it had rarely been considered in the past. Additionally, some constituents of CCR have been shown to be accumulated by adults and transferred to offspring, sometimes compromising offspring health. Studies have demonstrated that amphibians, possessing complex life cycles, may accumulate and transfer some contaminants to terrestrial systems. Some study has been given to molecular and cellular effects of CCR exposure, although these studies have been limited to invertebrates. Population models have also been applied to CCR affected systems and have shown that CCR may affect animal populations under some conditions. In light of these advancements, there are several topics that require further assessment. First, more attention to Hg and its dynamics in CCR affected systems is warranted. Hg can be highly accumulative and toxic under some conditions and may interact with other components of CCR (notably Se), perhaps altering accumulation and effects of the contaminant mixtures. Second, further investigation of maternal transfer and effects of CCR contaminants need to be conducted. These studies could benefit from incorporation of quantitative models to project impacts on populations. Finally, more attention to the organic constituents of CCR (PAHs) is required, as a focus on inorganic compounds only may restrict our knowledge of contaminant dynamics and effects as a whole. While further studies will shed light on some chemical and biological nuances of exposure and effect, information available to date from numerous study sites implicates CCR as a bulk effluent that presents risks of bioaccumulation and effects on organisms

  11. PDF Modeling of Turbulent Combustion

    DTIC Science & Technology

    2008-11-30

    extend methodologies for the modeling and simulation of turbulent combustion. Probability density function (PDF) calculations were performed of piloted...were developed to implement the combined methodology of large-eddy simulation (LES) and filtered density function (FDF). Second-order schemes were...was to advance and extend methodologies for the modeling and simulation of turbulent combustion. Probability density function (PDF) calculations were

  12. Microgravity Combustion Diagnostics Workshop

    NASA Technical Reports Server (NTRS)

    Santoro, Gilbert J. (Editor); Greenberg, Paul S. (Editor); Piltch, Nancy D. (Editor)

    1988-01-01

    Through the Microgravity Science and Applications Division (MSAD) of the Office of Space Science and Applications (OSSA) at NASA Headquarters, a program entitled, Advanced Technology Development (ATD) was promulgated with the objective of providing advanced technologies that will enable the development of future microgravity science and applications experimental flight hardware. Among the ATD projects one, Microgravity Combustion Diagnostics (MCD), has the objective of developing advanced diagnostic techniques and technologies to provide nonperturbing measurements of combustion characteristics and parameters that will enhance the scientific integrity and quality of microgravity combustion experiments. As part of the approach to this project, a workshop was held on July 28 and 29, 1987, at the NASA Lewis Research Center. A small group of laser combustion diagnosticians met with a group of microgravity combustion experimenters to discuss the science requirements, the state-of-the-art of laser diagnostic technology, and plan the direction for near-, intermediate-, and long-term programs. This publication describes the proceedings of that workshop.

  13. Advanced Techniques for Neoclassical Tearing Mode Control by Electron Cyclotron Current Drive in DIII-D

    NASA Astrophysics Data System (ADS)

    Volpe, F.

    2008-11-01

    Novel techniques have been developed in DIII-D for (1) control of rapidly rotating neoclassical tearing modes (NTMs) and (2) control of NTMs that have locked to a residual error field or the resistive wall. Electron cyclotron current drive (ECCD) has been successful at suppression of NTMs in present tokamaks, but will face new challenges in ITER where NTMs are expected to be more prone to locking. In order to avoid locking, rotating islands must be controlled at small widths that are expected to be narrower than the ECCD deposition. Under these conditions, modulated ECCD is predicted to stabilize more efficiently than continuous current drive. (1) A new technique developed at DIII-D detects the island using oblique electron cyclotron emission with a line of sight equivalent to that of the ECCD. This removes much of the uncertainty in mapping the island structure from the detector to the current drive location. This method was used both to measure the radial alignment between ECCD and the island, and to synchronize the modulation in phase with the island O-point, successfully stabilizing an NTM with mode numbers m/n=3/2. (2) If islands do grow large enough to lock, locked mode control will be necessary for recovery or avoiding disruption in ITER. A potential difficulty associated with locking is that the mode can lock in a position not necessarily accessible to ECCD. To obviate this problem, magnetic perturbations were used for the first time to unlock and reposition a locked m/n=2/1 mode in order to bring it in view of the gyrotron beam, leading to a significant reduction in island size. Once unlocked, magnetic perturbations were also used to sustain and control the mode rotation, which has the potential for easier ECCD modulation

  14. Feedback control of combustion oscillations in combustion chambers

    NASA Astrophysics Data System (ADS)

    Wei, Wei; Wang, Jing; Li, Dong-hai; Zhu, Min; Xue, Ya-li

    2010-11-01

    Model-based algorithms are generally employed in active control of combustion oscillations. Since practical combustion processes consist of complex thermal and acoustic couplings, their accurate models and parameters may not be obtained in advance economically, a model free controller is necessary for the control of thermoacoustic instabilities. Active compensation based control algorithm is applied in the suppression of combustion instabilities. Tuning the controller parameters on line, the amplitudes of the acoustic waves can be modulated to desired values. Simulations performed on a control oriented, typical longitudinal oscillations combustor model illustrate the controllers' capability to attenuate combustion oscillations.

  15. Engine combustion control responsive to location and magnitude of peak combustion pressure

    SciTech Connect

    Tombley, D.E.

    1987-11-17

    A combustion control is described for an internal combustion engine of the type having combustion chambers, means for supplying a combustible charge to and igniting the combustible charge within each combustion chamber, power output apparatus including a rotating crankshaft, and means for sensing the crankshaft angle (LPP) and magnitude (MPP) of peak combustion pressure for each combustion chamber. The combustion control consists of: means for deriving the average magnitude of peak combustion pressure (AMPP); means for determining base values; memory means for storing tables of LPP ignition trim values, MPP ignition trim values and A/F trim values for each combustion chamber; means for comparing the sensed LPP value for each combustion chamber with a desired LPP value (DLPP) for that combustion chamber and adjusting the LPP ignition trim value for the predetermined engine operating parameters; means for comparing the MPP value for each combustion chamber with the average magnitude of peak combustion pressure; means to adjust the A/F trim value in the rich direction and reset the MPP ignition trim value; means to adjust the MPP ignition trim value in the advance direction; means to adjust the A/F trim value in the lean direction and reset the MPP ignition trim value; means for determining the combustible charge mixture for each combustion chamber from the base value thereof and the A/F trim value for the sensed predetermined engine operating parameters; means for determining the ignition timing for each combustion.

  16. A Low NO(x) Lean-Direct Injection, Multipoint Integrated Module Combuster Concept for Advanced Aircraft Gas Turbines

    NASA Technical Reports Server (NTRS)

    Tacina, Robert; Wey, Changlie; Laing, Peter; Mansour, Adel

    2002-01-01

    A low NO(x) emissions combustor has been demonstrated in flame-tube tests. A multipoint, lean-direct injection concept was used. Configurations were tested that had 25- and 36- fuel injectors in the size of a conventional single fuel injector. An integrated-module approach was used for the construction where chemically etched laminates, diffusion bonded together, combine the fuel injectors, air swirlers and fuel manifold into a single element. Test conditions were inlet temperatures up to 810 K, inlet pressures up to 2760 kPa, and flame temperatures up to 2100 K. A correlation was developed relating the NO(x) emissions with the inlet temperature, inlet pressure, fuel-air ratio and pressure drop. Assuming that 10 percent of the combustion air would be used for liner cooling and using a hypothetical engine cycle, the NO(x) emissions using the correlation from flame-tube tests were estimated to be less than 20 percent of the 1996 ICAO standard.

  17. Building Shared Experience to Advance Practical Application of Pathway-Based Toxicology: Liver Toxicity Mode-of-Action

    PubMed Central

    Willett, Catherine; Rae, Jessica Caverly; Goyak, Katy O.; Minsavage, Gary; Westmoreland, Carl; Andersen, Melvin; Avigan, Mark; Duché, Daniel; Harris, Georgina; Hartung, Thomas; Jaeschke, Hartmut; Kleensang, Andre; Landesmann, Brigitte; Martos, Suzanne; Matevia, Marilyn; Toole, Colleen; Rowan, Andrew; Schultz, Terry; Seed, Jennifer; Senior, John; Shah, Imran; Subramanian, Kalyanasundaram; Vinken, Mathieu; Watkins, Paul

    2016-01-01

    Summary A workshop sponsored by the Human Toxicology Project Consortium (HTPC), “Building Shared Experience to Advance Practical Application of Pathway-Based Toxicology: Liver Toxicity Mode-of-Action” brought together experts from a wide range of perspectives to inform the process of pathway development and to advance two prototype pathways initially developed by the European Commission Joint Research Center (JRC): liver-specific fibrosis and steatosis. The first half of the workshop focused on the theory and practice of pathway development; the second on liver disease and the two prototype pathways. Participants agreed pathway development is extremely useful for organizing information and found that focusing the theoretical discussion on a specific AOP is helpful. It is important to include several perspectives during pathway development, including information specialists, pathologists, human health and environmental risk assessors, and chemical and product manufacturers, to ensure the biology is well captured and end use is considered. PMID:24535319

  18. WET-NZ Multi-Mode Wave Energy Converter Advancement Project

    SciTech Connect

    Klure, Justin

    2011-11-01

    Presentation from the 2011 Water Peer Review in which the principal investigator discussed the next steps to verify a multi-mode functionality of the WET-NZ device. This included overview of the approaches taken to perform wave tank testing, open ocean deployment, synthesis and analysis.

  19. Combustion Science for Cleaner Fuels

    SciTech Connect

    Ahmed, Musahid

    2014-10-17

    Musahid Ahmed discusses how he and his team use the Advanced Light Source (ALS) to study combustion chemistry at our '8 Big Ideas' Science at the Theater event on October 8th, 2014, in Oakland, California.

  20. Combustion Science for Cleaner Fuels

    ScienceCinema

    Ahmed, Musahid

    2016-07-12

    Musahid Ahmed discusses how he and his team use the Advanced Light Source (ALS) to study combustion chemistry at our '8 Big Ideas' Science at the Theater event on October 8th, 2014, in Oakland, California.

  1. Comparing the greenhouse gas emissions from three alternative waste combustion concepts.

    PubMed

    Vainikka, Pasi; Tsupari, Eemeli; Sipilä, Kai; Hupa, Mikko

    2012-03-01

    Three alternative condensing mode power and combined heat and power (CHP) waste-to-energy concepts were compared in terms of their impacts on the greenhouse gas (GHG) emissions from a heat and power generation system. The concepts included (i) grate, (ii) bubbling fluidised bed (BFB) and (iii) circulating fluidised bed (CFB) combustion of waste. The BFB and CFB take advantage of advanced combustion technology which enabled them to reach electric efficiency up to 35% and 41% in condensing mode, respectively, whereas 28% (based on the lower heating value) was applied for the grate fired unit. A simple energy system model was applied in calculating the GHG emissions in different scenarios where coal or natural gas was substituted in power generation and mix of fuel oil and natural gas in heat generation by waste combustion. Landfilling and waste transportation were not considered in the model. GHG emissions were reduced significantly in all of the considered scenarios where the waste combustion concepts substituted coal based power generation. With the exception of condensing mode grate incinerator the different waste combustion scenarios resulted approximately in 1 Mton of fossil CO(2)-eq. emission reduction per 1 Mton of municipal solid waste (MSW) incinerated. When natural gas based power generation was substituted by electricity from the waste combustion significant GHG emission reductions were not achieved.

  2. Recent Experimental Results Related to Ejector Mode Studies of Rocket-Based Combined Cycle (RBCC) Engines

    NASA Technical Reports Server (NTRS)

    Cramer, J. M.; Pal, S.; Marshall, W. M.; Santoro, R. J.

    2003-01-01

    Contents include the folloving: 1. Motivation. Support NASA's 3d generation launch vehicle technology program. RBCC is promising candidate for 3d generation propulsion system. 2. Approach. Focus on ejector mode p3erformance (Mach 0-3). Perform testing on established flowpath geometry. Use conventional propulsion measurement techniques. Use advanced optical diagnostic techniques to measure local combustion gas properties. 3. Objectives. Gain physical understanding of detailing mixing and combustion phenomena. Establish an experimental data set for CFD code development and validation.

  3. Some Factors Affecting Combustion in an Internal-Combustion Engine

    NASA Technical Reports Server (NTRS)

    Rothrock, A M; Cohn, Mildred

    1936-01-01

    An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) caused a decrease in the extent and rate of combustion. In almost all cases combustion improved with increased temperature. The results show that at low air temperatures the rates of combustion vary with the volatility of the fuel, but that at high temperatures this relationship does not exist and the rates depend to a greater extent on the chemical nature of the fuel.

  4. RECENT ADVANCES IN ARSENIC CARCINOGENESIS: MODES OF ACTION, ANIMAL MODEL SYSTEMS AND METHYLATED ARSENIC METABOLITES

    EPA Science Inventory


    Abstract:

    Recent advances in our knowledge of arsenic carcinogenesis include the development of rat or mouse models for all human organs in which inorganic arsenic is known to cause cancer -skin, lung, urinary bladder, liver and kidney. Tumors can be produced from eit...

  5. A Damage Model for the Simulation of Delamination in Advanced Composites under Variable-Mode Loading

    NASA Technical Reports Server (NTRS)

    Turon, A.; Camanho, P. P.; Costa, J.; Davila, C. G.

    2006-01-01

    A thermodynamically consistent damage model is proposed for the simulation of progressive delamination in composite materials under variable-mode ratio. The model is formulated in the context of Damage Mechanics. A novel constitutive equation is developed to model the initiation and propagation of delamination. A delamination initiation criterion is proposed to assure that the formulation can account for changes in the loading mode in a thermodynamically consistent way. The formulation accounts for crack closure effects to avoid interfacial penetration of two adjacent layers after complete decohesion. The model is implemented in a finite element formulation, and the numerical predictions are compared with experimental results obtained in both composite test specimens and structural components.

  6. Electron Pattern Recognition using trigger mode SOI pixel sensor for Advanced Compton Imaging

    NASA Astrophysics Data System (ADS)

    Shimazoe, K.; Yoshihara, Y.; Fairuz, A.; Koyama, A.; Takahashi, H.; Takeda, A.; Tsuru, T.; Arai, Y.

    2016-02-01

    Compton imaging is a useful method for localizing sub MeV to a few MeV gamma-rays and widely used for environmental and medical applications. The direction of recoiled electrons in Compton scattering process provides the additional information to limit the Compton cones and increases the sensitivity in the system. The capability of recoiled electron tracking using trigger-mode Silicon-On-Insulator (SOI) sensor is investigated with various radiation sources. The trigger-mode SOI sensor consists of 144 by 144 active pixels with 30 μm cells and the thickness of sensor is 500 μm. The sensor generates the digital output when it is hit by gamma-rays and 25 by 25 pixel pattern of surrounding the triggered pixel is readout to extract the recoiled electron track. The electron track is successfully observed for 60Co and 137Cs sources, which provides useful information for future electron tracking Compton camera.

  7. Advanced techniques for neoclassical tearing mode control in DIII-Da)

    NASA Astrophysics Data System (ADS)

    Volpe, F. A. G.; Austin, M. E.; La Haye, R. J.; Lohr, J.; Prater, R.; Strait, E. J.; Welander, A. S.

    2009-10-01

    Two techniques were developed at DIII-D [J. L. Luxon, Nucl. Fusion 42, 64 (2002)] to tackle ITER-specific aspects of neoclassical tearing mode (NTM) control, namely, (1) the relatively small size of the rotating islands, smaller than the electron cyclotron current drive (ECCD) deposition region, and (2) the increased tendency of the islands, compared to present devices, to lock to the wall or to the residual error field, in a position not necessarily accessible to ECCD. Modulated ECCD is known to suppress small islands more efficiently, when "broad," than continuous ECCD. At DIII-D, a NTM of poloidal/toroidal mode numbers m /n=3/2 was completely stabilized by a new technique where oblique electron cyclotron emission acted at the same time as an indicator of good alignment between ECCD and the island, and as a waveform generator, for modulation in synch and in phase with the island O-point. In another experiment, after locking in an unfavorable position, a 2/1 island was steered by externally generated magnetic perturbations, brought in the view of the gyrotrons and partly stabilized by ECCD in the island O-point. Magnetic perturbations were also used to sustain and control the mode rotation, which has the potential for an easier ECCD modulation.

  8. Simulation of the hybrid and steady state advanced operating modes in ITER

    NASA Astrophysics Data System (ADS)

    Kessel, C. E.; Giruzzi, G.; Sips, A. C. C.; Budny, R. V.; Artaud, J. F.; Basiuk, V.; Imbeaux, F.; Joffrin, E.; Schneider, M.; Murakami, M.; Luce, T.; St. John, Holger; Oikawa, T.; Hayashi, N.; Takizuka, T.; Ozeki, T.; Na, Y.-S.; Park, J. M.; Garcia, J.; Tucillo, A. A.

    2007-09-01

    Integrated simulations are performed to establish a physics basis, in conjunction with present tokamak experiments, for the operating modes in the International Thermonuclear Experimental Reactor (ITER). Simulations of the hybrid mode are done using both fixed and free-boundary 1.5D transport evolution codes including CRONOS, ONETWO, TSC/TRANSP, TOPICS and ASTRA. The hybrid operating mode is simulated using the GLF23 and CDBM05 energy transport models. The injected powers are limited to the negative ion neutral beam, ion cyclotron and electron cyclotron heating systems. Several plasma parameters and source parameters are specified for the hybrid cases to provide a comparison of 1.5D core transport modelling assumptions, source physics modelling assumptions, as well as numerous peripheral physics modelling. Initial results indicate that very strict guidelines will need to be imposed on the application of GLF23, for example, to make useful comparisons. Some of the variations among the simulations are due to source models which vary widely among the codes used. In addition, there are a number of peripheral physics models that should be examined, some of which include fusion power production, bootstrap current, treatment of fast particles and treatment of impurities. The hybrid simulations project to fusion gains of 5.6-8.3, βN values of 2.1-2.6 and fusion powers ranging from 350 to 500 MW, under the assumptions outlined in section 3. Simulations of the steady state operating mode are done with the same 1.5D transport evolution codes cited above, except the ASTRA code. In these cases the energy transport model is more difficult to prescribe, so that energy confinement models will range from theory based to empirically based. The injected powers include the same sources as used for the hybrid with the possible addition of lower hybrid. The simulations of the steady state mode project to fusion gains of 3.5-7, βN values of 2.3-3.0 and fusion powers of 290 to 415 MW

  9. Experimental and Computational Characterization of Combustion Phenomena

    DTIC Science & Technology

    2006-05-01

    Fundamental Combustion Advanced Combustor Concepts Combustor Demonstration and Transition Figure 1. A design philosophy for transitioning basic...PFP UNCLASSIFIED [4] W.-W. Kim, S. Menon, and H. Mongia , “Large-Eddy Simulation of a Gas Turbine Combustor Flow,” Combust . Sci. Technol. 143, 25-62...AFRL-PR-WP-TM-2006-2131 EXPERIMENTAL AND COMPUTATIONAL CHARACTERIZATION OF COMBUSTION PHENOMENA Dr. James R. Gord Combustion Branch (AFRL

  10. Simulating Combustion

    NASA Astrophysics Data System (ADS)

    Merker, G.; Schwarz, C.; Stiesch, G.; Otto, F.

    The content spans from simple thermodynamics of the combustion engine to complex models for the description of the air/fuel mixture, ignition, combustion and pollutant formation considering the engine periphery of petrol and diesel engines. Thus the emphasis of the book is on the simulation models and how they are applicable for the development of modern combustion engines. Computers can be used as the engineers testbench following the rules and recommendations described here.

  11. Pilot-Scale Evaluation of an Advanced Carbon Sorbent-Based Process for Post-Combustion Carbon Capture

    SciTech Connect

    Hornbostel, Marc

    2016-09-01

    The overall objective of this project is to achieve the DOE’s goal to develop advanced CO2 capture and separation technologies that can realize at least 90% CO2 removal from flue gas steams produced at a pulverized coal (PC) power plant at a cost of less than $40/tonne of CO2 captured. The principal objective is to test a CO2 capture process that will reduce the parasitic plant load by using a CO2 capture sorbent that will require a reduced amount of steam. The process is based on advanced carbon sorbents having a low heat of adsorption, high CO2 adsorption capacity, and excellent selectivity. While the intent of this project was to produce design and performance data by testing the sorbent using a slipstream of coal-derived flue gas at the National Carbon Capture Center (NCCC) under realistic conditions and continuous long-term operation, the project was terminated following completion of the detailing pilot plant design/engineering work on June 30, 2016.

  12. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO sub x ) emissions from coal-fired boilers

    SciTech Connect

    Not Available

    1992-02-03

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company's Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an Advanced Overfire Air (AOFA) system followed by Low NO{sub x} Burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency.

  13. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, third quarter 1991

    SciTech Connect

    Not Available

    1992-02-03

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an Advanced Overfire Air (AOFA) system followed by Low NO{sub x} Burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency.

  14. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO[sub x]) emissions from coal-fired boilers

    SciTech Connect

    Not Available

    1992-08-24

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (No[sub x]) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company's Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO[sub x] combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO[sub x] reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO[sub x] burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO[sub x] reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency.

  15. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, Second quarter 1992

    SciTech Connect

    Not Available

    1992-08-24

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (No{sub x}) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency.

  16. Advances in High Harmonic Fast Wave Heating of NSTX H-mode Plasmas

    SciTech Connect

    Ryan, Philip Michael; Ahn, Joonwook; Bell, R. E.; Bonoli, P.; Chen, Guangye; Green, David L; Harvey, R. W.; Hosea, J.; Jaeger, Erwin Frederick; Kaye, S.; LeBlanc, B; Maingi, Rajesh; Phillips, Cynthia; Podesta, M.; Taylor, G.; Wilgen, John B; Wilson, J. R.

    2010-01-01

    High-harmonic fast wave (HHFW) heating and current drive is being developed in NSTX to provide bulk electron heating and q(0) control during non-inductively sustained Hmode plasmas fuelled by deuterium neutral-beam injection (NBI). In addition, it is used to assist the plasma current ramp-up. A major modification to increase the RF power limit was made in 2009; the original end-grounded, single end-powered current straps of the 12- element array were replaced with center-grounded, double end-powered straps. Greater than 3 MW have been coupled into NBI-driven, ELMy H-mode plasmas with this upgraded antenna. Improved core HHFW heating, particularly at longer wavelengths and during low-density start-up and plasma current ramp-up, has been obtained by lowering the edge density with lithium wall conditioning, thereby moving the critical density for fast-wave propagation away from the vessel wall [1]. Significant core electron heating of NBI-fuelled H-modes has been observed for the first time over a range of launched wavelengths and H-modes can be accessed by HHFW alone. Visible and IR camera images of the antenna and divertor indicate that fast wave interactions can deposit considerable RF energy on the outboard divertor plate, especially at longer wavelengths that begin to propagate closer to the vessel walls. Edge power loss can also arise from HHFWgenerated parametric decay instabilities; edge ion heating is observed that is wavelength dependent. During plasmas where HHFW is combined with NBI, there is a significant enhancement in neutron rate, and fast-ion D-alpha (FIDA) emission measurements clearly show broadening of the fast-ion profile in the plasma core. Large edge localized modes (ELMs) have been observed immediately following the termination of RF power, whether the power turn off is programmed or due to antenna arcing. Causality has not been established but new experiments are planned and will be reported. Fast digitization of the reflected power signal

  17. Load-cell based characterization system for a "Violin-Mode" shadow-sensor in advanced LIGO suspensions

    NASA Astrophysics Data System (ADS)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which 40 kg test-mass/mirrors are each suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation and a rectangular silicon photodiode detector, which, together, were to bracket the fibre under test. The aim was to detect transverse Violin-Mode resonances in the suspension fibres. Part of the testing procedure involved tensioning a silica fibre sample and translating it transversely through the illuminating NIR beam, so as to measure the DC responsivity of the detection system to fibre displacement. However, an equally important part of the procedure, reported here, was to keep the fibre under test stationary within the beam, whilst trying to detect low-level AC Violin-Mode resonances excited on the fibre, in order to confirm the primary function of the sensor. Therefore, a tensioning system, incorporating a load-cell readout, was built into the test fibre's holder. The fibre then was excited by a signal generator, audio power amplifier, and distant loudspeaker, and clear resonances were detected. A theory for the expected fundamental resonant frequency as a function of fibre tension was developed and is reported here, and this theory was found to match closely with the detected resonant frequencies as they varied with tension. Consequently, the resonances seen were identified as being proper Violin-Mode fundamental resonances of the fibre, and the operation of the Violin-Mode detection system was validated.

  18. Load-cell based characterization system for a "Violin-Mode" shadow-sensor in advanced LIGO suspensions.

    PubMed

    Lockerbie, N A; Tokmakov, K V

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which 40 kg test-mass/mirrors are each suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation and a rectangular silicon photodiode detector, which, together, were to bracket the fibre under test. The aim was to detect transverse Violin-Mode resonances in the suspension fibres. Part of the testing procedure involved tensioning a silica fibre sample and translating it transversely through the illuminating NIR beam, so as to measure the DC responsivity of the detection system to fibre displacement. However, an equally important part of the procedure, reported here, was to keep the fibre under test stationary within the beam, whilst trying to detect low-level AC Violin-Mode resonances excited on the fibre, in order to confirm the primary function of the sensor. Therefore, a tensioning system, incorporating a load-cell readout, was built into the test fibre's holder. The fibre then was excited by a signal generator, audio power amplifier, and distant loudspeaker, and clear resonances were detected. A theory for the expected fundamental resonant frequency as a function of fibre tension was developed and is reported here, and this theory was found to match closely with the detected resonant frequencies as they varied with tension. Consequently, the resonances seen were identified as being proper Violin-Mode fundamental resonances of the fibre, and the operation of the Violin-Mode detection system was validated.

  19. Advances in generation of high-repetition-rate burst mode laser output.

    PubMed

    Jiang, Naibo; Webster, Matthew C; Lempert, Walter R

    2009-02-01

    It is demonstrated that the incorporation of variable pulse duration flashlamp power supplies into an Nd:YAG burst mode laser system results in very substantial increases in the realizable energy per pulse, the total pulse train length, and uniformity of the intensity envelope. As an example, trains of 20 pulses at burst frequencies of 50 and 20 kHz are demonstrated with individual pulse energy at 1064 nm of 220 and 400 mJ, respectively. Conversion efficiency to the second- (532 nm) and third- (355 nm) harmonic wavelengths of approximately 50% and 35-40%, respectively, is also achieved. Use of the third-harmonic output of the burst mode laser as a pump source for a simple, home built optical parametric oscillator (OPO) produces pulse trains of broadly wavelength tunable output. Sum-frequency mixing of OPO signal output at 622 nm with residual output from the 355 nm pump beam is shown to produce uniform bursts of tunable output at approximately 226 nm, with individual pulse energy of approximately 0.5 mJ. Time-correlated NO planar laser induced fluorescence (PLIF) image sequences are obtained in a Mach 3 wind tunnel at 500 kHz, representing, to our knowledge, the first demonstration of NO PLIF imaging at repetition rates exceeding tens of hertz.

  20. Advanced Shock Position Control for Mode Transition in a Turbine Based Combined Cycle Engine Inlet Model

    NASA Technical Reports Server (NTRS)

    Csank, Jeffrey T.; Stueber, Thomas J.

    2013-01-01

    A dual flow-path inlet system is being tested to evaluate methodologies for a Turbine Based Combined Cycle (TBCC) propulsion system to perform a controlled inlet mode transition. Prior to experimental testing, simulation models are used to test, debug, and validate potential control algorithms. One simulation package being used for testing is the High Mach Transient Engine Cycle Code simulation, known as HiTECC. This paper discusses the closed loop control system, which utilizes a shock location sensor to improve inlet performance and operability. Even though the shock location feedback has a coarse resolution, the feedback allows for a reduction in steady state error and, in some cases, better performance than with previous proposed pressure ratio based methods. This paper demonstrates the design and benefit with the implementation of a proportional-integral controller, an H-Infinity based controller, and a disturbance observer based controller.

  1. Advanced engine study for mixed-mode orbit-transfer vehicles

    NASA Technical Reports Server (NTRS)

    Mellish, J. A.

    1978-01-01

    Engine design, performance, weight and envelope data were established for three mixed-mode orbit-transfer vehicle engine candidates. Engine concepts evaluated are the tripropellant, dual-expander and plug cluster. Oxygen, RP-1 and hydrogen are the propellants considered for use in these engines. Theoretical performance and propellant properties were established for bipropellant and tripropellant mixes of these propellants. RP-1, hydrogen and oxygen were evaluated as coolants and the maximum attainable chamber pressures were determined for each engine concept within the constraints of the propellant properties and the low cycle thermal fatigue (300 cycles) requirement. The baseline engine design and component operating characteristics are determined at a thrust level of 88,964N (20,000 lbs) and a thrust split of 0.5. The parametric data is generated over ranges of thrust and thrust split of 66.7 to 400kN (15 to 90 klb) and 0.4 to 0.8, respectively.

  2. Ames Hybrid Combustion Facility

    NASA Technical Reports Server (NTRS)

    Zilliac, Greg; Karabeyoglu, Mustafa A.; Cantwell, Brian; Hunt, Rusty; DeZilwa, Shane; Shoffstall, Mike; Soderman, Paul T.; Bencze, Daniel P. (Technical Monitor)

    2003-01-01

    The report summarizes the design, fabrication, safety features, environmental impact, and operation of the Ames Hybrid-Fuel Combustion Facility (HCF). The facility is used in conducting research into the scalability and combustion processes of advanced paraffin-based hybrid fuels for the purpose of assessing their applicability to practical rocket systems. The facility was designed to deliver gaseous oxygen at rates between 0.5 and 16.0 kg/sec to a combustion chamber operating at pressures ranging from 300 to 900. The required run times were of the order of 10 to 20 sec. The facility proved to be robust and reliable and has been used to generate a database of regression-rate measurements of paraffin at oxygen mass flux levels comparable to those of moderate-sized hybrid rocket motors.

  3. Droplet Combustion Experiment movie

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Droplet Combustion Experiment (DCE) was designed to investigate the fundamental combustion aspects of single, isolated droplets under different pressures and ambient oxygen concentrations for a range of droplet sizes varying between 2 and 5 mm. The DCE principal investigator was Forman Williams, University of California, San Diego. The experiment was part of the space research investigations conducted during the Microgravity Science Laboratory-1 mission (STS-83, April 4-8 1997; the shortened mission was reflown as MSL-1R on STS-94). Advanced combustion experiments will be a part of investigations plarned for the International Space Station. (1.1 MB, 12-second MPEG, screen 320 x 240 pixels; downlinked video, higher quality not available)A still JPG composite of this movie is available at http://mix.msfc.nasa.gov/ABSTRACTS/MSFC-0300164.html.

  4. Fluidized-bed combustion

    SciTech Connect

    Botros, P E

    1990-04-01

    This report describes the activities of the Morgantown Energy Technology Center's research and development program in fluidized-bed combustion from October 1, 1987, to September 30, 1989. The Department of Energy program involves atmospheric and pressurized systems. Demonstrations of industrial-scale atmospheric systems are being completed, and smaller boilers are being explored. These systems include vortex, multi-solid, spouted, dual-sided, air-cooled, pulsed, and waste-fired fluidized-beds. Combustion of low-rank coal, components, and erosion are being studied. In pressurized combustion, first-generation, combined-cycle power plants are being tested, and second-generation, advanced-cycle systems are being designed and cost evaluated. Research in coal devolatilization, metal wastage, tube corrosion, and fluidization also supports this area. 52 refs., 24 figs., 3 tabs.

  5. Combustion 2000

    SciTech Connect

    2000-06-30

    This report presents work carried out under contract DE-AC22-95PC95144 ''Combustion 2000 - Phase II.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: {lg_bullet} thermal efficiency (HHV) {ge} 47% {lg_bullet} NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) {lg_bullet} coal providing {ge} 65% of heat input {lg_bullet} all solid wastes benign {lg_bullet} cost of electricity {le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: {lg_bullet} Task 2.2.4 Pilot Scale Testing {lg_bullet} Task 2.2.5.2 Laboratory and Bench Scale Activities

  6. Lower hybrid current drive and ion cyclotron range of frequencies heating experiments in H-mode plasmas in Experimental Advanced Superconducting Tokomak

    SciTech Connect

    Zhang, X. J.; Wan, B. N. Zhao, Y. P.; Ding, B. J.; Xu, G. S.; Gong, X. Z.; Li, J. G.; Lin, Y.; Wukitch, S.; Taylor, G.; Noterdaeme, J. M.; Braun, F.; Magne, R.; Litaudon, X.; Kumazawa, R.; Kasahara, H.

    2014-06-15

    An ion cyclotron range of frequencies (ICRF) system with power up to 6.0 MW and a lower hybrid current drive (LHCD) system up to 4 MW have been applied for heating and current drive experiments in Experimental Advanced Superconducting Tokomak (EAST). Significant progress has been made with ICRF heating and LHCD for realizing the H-mode plasma operation in EAST. During 2010 and 2012 experimental campaigns, ICRF heating experiments were carried out at the fixed frequency of 27MHz, achieving effective ions and electrons heating with the H minority heating (H-MH) mode. The H-MH mode produced good plasma performance, and realized H-mode using ICRF power alone in 2012. In 2010, H-modes were generated and sustained by LHCD alone, where lithium coating and gas puffing near the mouth of the LH launcher were applied to improve the LHCD power coupling and penetration into the core plasmas of H-modes. In 2012, the combination of LHCD and ICRH power extended the H-mode duration up to over 30 s. H-modes with various types of edge localized modes (ELMs) have been achieved with H{sub IPB98}(y, 2) ranging from 0.7 to over unity. A brief overview of LHCD and ICRF Heating experiment and their application in achieving H-mode operation during these two campaigns will be presented.

  7. Innovative clean coal technology: 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. Final report, Phases 1 - 3B

    SciTech Connect

    1998-01-01

    This report presents the results of a U.S. Department of Energy (DOE) Innovative Clean Coal Technology (ICCT) project demonstrating advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The project was conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The technologies demonstrated at this site include Foster Wheeler Energy Corporation`s advanced overfire air system and Controlled Flow/Split Flame low NOx burner. The primary objective of the demonstration at Hammond Unit 4 was to determine the long-term effects of commercially available wall-fired low NOx combustion technologies on NOx emissions and boiler performance. Short-term tests of each technology were also performed to provide engineering information about emissions and performance trends. A target of achieving fifty percent NOx reduction using combustion modifications was established for the project. Short-term and long-term baseline testing was conducted in an {open_quotes}as-found{close_quotes} condition from November 1989 through March 1990. Following retrofit of the AOFA system during a four-week outage in spring 1990, the AOFA configuration was tested from August 1990 through March 1991. The FWEC CF/SF low NOx burners were then installed during a seven-week outage starting on March 8, 1991 and continuing to May 5, 1991. Following optimization of the LNBs and ancillary combustion equipment by FWEC personnel, LNB testing commenced during July 1991 and continued until January 1992. Testing in the LNB+AOFA configuration was completed during August 1993. This report provides documentation on the design criteria used in the performance of this project as it pertains to the scope involved with the low NOx burners and advanced overfire systems.

  8. Combustion Instabilities Modeled

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E.

    1999-01-01

    NASA Lewis Research Center's Advanced Controls and Dynamics Technology Branch is investigating active control strategies to mitigate or eliminate the combustion instabilities prevalent in lean-burning, low-emission combustors. These instabilities result from coupling between the heat-release mechanisms of the burning process and the acoustic flow field of the combustor. Control design and implementation require a simulation capability that is both fast and accurate. It must capture the essential physics of the system, yet be as simple as possible. A quasi-one-dimensional, computational fluid dynamics (CFD) based simulation has been developed which may meet these requirements. The Euler equations of mass, momentum, and energy have been used, along with a single reactive species transport equation to simulate coupled thermoacoustic oscillations. A very simple numerical integration scheme was chosen to reduce computing time. Robust boundary condition procedures were incorporated to simulate various flow conditions (e.g., valves, open ends, and choked inflow) as well as to accommodate flow reversals that may arise during large flow-field oscillations. The accompanying figure shows a sample simulation result. A combustor with an open inlet, a choked outlet, and a large constriction approximately two thirds of the way down the length is shown. The middle plot shows normalized, time-averaged distributions of the relevant flow quantities, and the bottom plot illustrates the acoustic mode shape of the resulting thermoacoustic oscillation. For this simulation, the limit cycle peak-to-peak pressure fluctuations were 13 percent of the mean. The simulation used 100 numerical cells. The total normalized simulation time was 50 units (approximately 15 oscillations), which took 26 sec on a Sun Ultra2.

  9. Can currently available advanced combustion biomass cook-stoves provide health relevant exposure reductions? Results from initial assessment of select commercial models in India.

    PubMed

    Sambandam, Sankar; Balakrishnan, Kalpana; Ghosh, Santu; Sadasivam, Arulselvan; Madhav, Satish; Ramasamy, Rengaraj; Samanta, Maitreya; Mukhopadhyay, Krishnendu; Rehman, Hafeez; Ramanathan, Veerabhadran

    2015-03-01

    Household air pollution from use of solid fuels is a major contributor to the national burden of disease in India. Currently available models of advanced combustion biomass cook-stoves (ACS) report significantly higher efficiencies and lower emissions in the laboratory when compared to traditional cook-stoves, but relatively little is known about household level exposure reductions, achieved under routine conditions of use. We report results from initial field assessments of six commercial ACS models from the states of Tamil Nadu and Uttar Pradesh in India. We monitored 72 households (divided into six arms to each receive an ACS model) for 24-h kitchen area concentrations of PM2.5 and CO before and (1-6 months) after installation of the new stove together with detailed information on fixed and time-varying household characteristics. Detailed surveys collected information on user perceptions regarding acceptability for routine use. While the median percent reductions in 24-h PM2.5 and CO concentrations ranged from 2 to 71% and 10-66%, respectively, concentrations consistently exceeded WHO air quality guideline values across all models raising questions regarding the health relevance of such reductions. Most models were perceived to be sub-optimally designed for routine use often resulting in inappropriate and inadequate levels of use. Household concentration reductions also run the risk of being compromised by high ambient backgrounds from community level solid-fuel use and contributions from surrounding fossil fuel sources. Results indicate that achieving health relevant exposure reductions in solid-fuel using households will require integration of emissions reductions with ease of use and adoption at community scale, in cook-stove technologies. Imminent efforts are also needed to accelerate the progress towards cleaner fuels.

  10. An AC modulated near infrared gain calibration system for a "Violin-Mode" transimpedance amplifier, intended for advanced LIGO suspensions.

    PubMed

    Lockerbie, N A; Tokmakov, K V

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a "tall-thin" rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse "Violin-Mode" vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor's DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor's more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz-300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m(-1) was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC/DC transimpedance gain

  11. An AC modulated near infrared gain calibration system for a "Violin-Mode" transimpedance amplifier, intended for advanced LIGO suspensions

    NASA Astrophysics Data System (ADS)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a "tall-thin" rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse "Violin-Mode" vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor's DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor's more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz-300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m-1 was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC/DC transimpedance gain ratio

  12. Thermal Model of the Promoted Combustion Test

    NASA Technical Reports Server (NTRS)

    Jones, Peter D.

    1996-01-01

    Flammability of metals in high pressure, pure oxygen environments, such as rocket engine turbopumps, is commonly evaluated using the Promoted Combustion Test (PCT). The PCT emphasizes the ability of an ignited material to sustain combustion, as opposed to evaluating the sample's propensity to ignite in the first place. A common arrangement is a rod of the sample material hanging in a chamber in which a high pressure, pure oxygen environment is maintained. An igniter of some energetically combusting material is fixed to the bottom of the rod and fired. This initiates combustion, and the sample burns and melts at its bottom tip. A ball of molten material forms, and this ball detaches when it grows too large to be supported by surface tension with the rod. In materials which do not sustain combustion, the combustion then extinguishes. In materials which do sustain combustion, combustion re-initiates from molten residue left on the bottom of the rod, and the melt ball burns and grows until it detaches again. The purpose of this work is development of a PCT thermal simulation model, detailing phase change, melt detachment, and the several heat transfer modes. Combustion is modeled by a summary rate equation, whose parameters are identified by comparison to PCT results. The sensitivity of PCT results to various physical and geometrical parameters is evaluated. The identified combustion parameters may be used in design of new PCT arrangements, as might be used for flammability assessment in flow-dominated environments. The Haynes 214 nickel-based superalloy, whose PCT results are applied here, burns heterogeneously (fuel and oxidizer are of different phases; combustion takes place on the fuel surface). Heterogeneous combustion is not well understood. (In homogeneous combustion, the metal vaporizes, and combustion takes place in an analytically treatable cloud above the surface). Thermal modeling in heterogeneous combustion settings provides a means for linking test

  13. Synergies of PCCI-Type Combustion and Lean NOx Trap Catalysis for Diesel Engines

    SciTech Connect

    Parks, II, James E; Prikhodko, Vitaly Y; Kass, Michael D; Huff, Shean P

    2008-01-01

    It is widely recognized that future NOx and PM emission targets for diesel engines cannot be met solely via advanced combustion over the full engine drive cycle. Therefore some combination of advanced combustion methodology with an aftertreatment technology will be required. In this study, NOx reduction, fuel efficiency, and regeneration performance of lean NOx trap (LNT) were evaluated for four operating conditions. The combustion approaches included baseline engine operation with and without EGR, two exhaust enrichment methods (post injection and delayed injection), and one advanced combustion mode to enable high efficiency clean combustion (HECC). A 1.7 liter 4-cylinder diesel engine was operated under five conditions, which represent key interest points for light-duty diesel operation. At the low load setting the exhaust temperature was too low to enable LNT regeneration and oxidation; however, HECC (low NOx) was achievable. HECC was also reached under more moderate loads and the exhaust temperatures were high enough to enable even further NOx reductions by the LNT. At high loads HECC becomes difficult but the LNT performance improves and acceptable regeneration can be met with enrichment methodologies.

  14. National Combustion Code: Parallel Performance

    NASA Technical Reports Server (NTRS)

    Babrauckas, Theresa

    2001-01-01

    This report discusses the National Combustion Code (NCC). The NCC is an integrated system of codes for the design and analysis of combustion systems. The advanced features of the NCC meet designers' requirements for model accuracy and turn-around time. The fundamental features at the inception of the NCC were parallel processing and unstructured mesh. The design and performance of the NCC are discussed.

  15. 180 MW demonstration of advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report second quarter, 1991

    SciTech Connect

    Not Available

    1991-12-31

    ABB CE`s Low NOx Bulk Furnace Staging (LNBFS) System and Low NOx Concentric Firing System (LNCFS) are demonstrated in stepwise fashion. These systems incorporate the concept of advanced overfire air (AOFA), clustered coal nozzles, and offset air. A complete description of the installed technologies is provided in the following section. The primary objective of the Plant Lansing Smith demonstration is to determine the long-term effects of commercially available tangentially-fired low NOx combustion technologies on NOx emissions and boiler performance. Short-term tests of each technology are also being performed to provide engineering information about emissions and performance trends. A target of achieving fifty percent NOx reduction using combustion modifications has been established for the project.

  16. Combustion diagnostic for active engine feedback control

    DOEpatents

    Green, Jr., Johney Boyd; Daw, Charles Stuart; Wagner, Robert Milton

    2007-10-02

    This invention detects the crank angle location where combustion switches from premixed to diffusion, referred to as the transition index, and uses that location to define integration limits that measure the portions of heat released during the combustion process that occur during the premixed and diffusion phases. Those integrated premixed and diffusion values are used to develop a metric referred to as the combustion index. The combustion index is defined as the integrated diffusion contribution divided by the integrated premixed contribution. As the EGR rate is increased enough to enter the low temperature combustion regime, PM emissions decrease because more of the combustion process is occurring over the premixed portion of the heat release rate profile and the diffusion portion has been significantly reduced. This information is used to detect when the engine is or is not operating in a low temperature combustion mode and provides that feedback to an engine control algorithm.

  17. Modes of Governmentality in an Online Space: A Case Study of Blog Activities in an Advanced Level Japanese-as-a-Foreign-Language Classroom

    ERIC Educational Resources Information Center

    Doerr, Neriko M.; Sato, Shinji

    2011-01-01

    This article discusses the validity of the incorporation of online communication in language education classes as a practice free of power politics. By examining blog activities in an advanced-level Japanese-as-a-Foreign-Language classroom at a university in the USA, we show that the blog's postings and readers' comments evoke certain modes of…

  18. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, Fourth quarter 1992

    SciTech Connect

    Not Available

    1992-12-31

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x } reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. Baseline, AOFA, and LNB without AOFA test segments have been completed. Analysis of the 94 days of LNB tong-term data collected show the full load NO{sub x} emission levels to be approximately 0.65 lb/MBtu. Flyash LOI values for the LNB configuration are approximately 8 percent at full load. Corresponding values for the AOFA configuration are 0.94 lb/MBtu and approximately 10 percent. Abbreviated diagnostic tests for the LNB+AOFA configuration indicate that at 500 MWe, NO{sub x} emissions are approximately 0.55 lb/MBtu with corresponding flyash LOI values of approximately 11 percent. For comparison, the long-term, full load, baseline NO{sub x} emission level was approximately 1.24 lb/MBtu at 5.2 percent LOI. Comprehensive testing of the LNB+AOFA configuration will be performed when the stack particulate emissions issue is resolved.

  19. Comparing the greenhouse gas emissions from three alternative waste combustion concepts

    SciTech Connect

    Vainikka, Pasi; Tsupari, Eemeli; Sipilae, Kai; Hupa, Mikko

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Significant GHG reductions are possible by efficient WtE technologies. Black-Right-Pointing-Pointer CHP and high power-to-heat ratio provide significant GHG savings. Black-Right-Pointing-Pointer N{sub 2}O and coal mine type are important in LCA GHG emissions of FBC co-combustion. Black-Right-Pointing-Pointer Substituting coal and fuel oil by waste is beneficial in electricity and heat production. Black-Right-Pointing-Pointer Substituting natural gas by waste may not be reasonable in CHP generation. - Abstract: Three alternative condensing mode power and combined heat and power (CHP) waste-to-energy concepts were compared in terms of their impacts on the greenhouse gas (GHG) emissions from a heat and power generation system. The concepts included (i) grate, (ii) bubbling fluidised bed (BFB) and (iii) circulating fluidised bed (CFB) combustion of waste. The BFB and CFB take advantage of advanced combustion technology which enabled them to reach electric efficiency up to 35% and 41% in condensing mode, respectively, whereas 28% (based on the lower heating value) was applied for the grate fired unit. A simple energy system model was applied in calculating the GHG emissions in different scenarios where coal or natural gas was substituted in power generation and mix of fuel oil and natural gas in heat generation by waste combustion. Landfilling and waste transportation were not considered in the model. GHG emissions were reduced significantly in all of the considered scenarios where the waste combustion concepts substituted coal based power generation. With the exception of condensing mode grate incinerator the different waste combustion scenarios resulted approximately in 1 Mton of fossil CO{sub 2}-eq. emission reduction per 1 Mton of municipal solid waste (MSW) incinerated. When natural gas based power generation was substituted by electricity from the waste combustion significant GHG emission reductions were not achieved.

  20. Combustion 2000

    SciTech Connect

    1999-12-31

    This report presents work carried out under contract DE-AC22-95PC95144 ''Combustion 2000 - Phase II.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: {lg_bullet} thermal efficiency (HHV) {ge} 47% {lg_bullet} NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) {lg_bullet} coal providing {ge} 65% of heat input {lg_bullet} all solid wastes benign {lg_bullet} cost of electricity {le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site-specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: {lg_bullet} Task 2.2.4 Pilot Scale Testing {lg_bullet} Task 2.2.5.2 Laboratory and Bench Scale Activities

  1. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. Public design report (preliminary and final)

    SciTech Connect

    1996-07-01

    This Public Design Report presents the design criteria of a DOE Innovative Clean Coal Technology (ICCT) project demonstrating advanced wall-fired combustion techniques for the reduction of NO{sub x} emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 (500 MW) near Rome, Georgia. The technologies being demonstrated at this site include Foster Wheeler Energy Corporation`s advanced overfire air system and Controlled Flow/Split Flame low NO{sub x} burner. This report provides documentation on the design criteria used in the performance of this project as it pertains to the scope involved with the low NO{sub x} burners, advanced overfire systems, and digital control system.

  2. Combustion 2000

    SciTech Connect

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

    2001-06-30

    . To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization

  3. Biofuels Combustion

    NASA Astrophysics Data System (ADS)

    Westbrook, Charles K.

    2013-04-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  4. Biofuels combustion.

    PubMed

    Westbrook, Charles K

    2013-01-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  5. Biofuels combustion*

    SciTech Connect

    Westbrook, Charles K.

    2013-01-04

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. As a result, research efforts on so-called second- and third-generation biofuels are discussed briefly.

  6. Bubble Combustion

    NASA Technical Reports Server (NTRS)

    Corrigan, Jackie

    2004-01-01

    A method of energy production that is capable of low pollutant emissions is fundamental to one of the four pillars of NASA s Aeronautics Blueprint: Revolutionary Vehicles. Bubble combustion, a new engine technology currently being developed at Glenn Research Center promises to provide low emissions combustion in support of NASA s vision under the Emissions Element because it generates power, while minimizing the production of carbon dioxide (CO2) and nitrous oxides (NOx), both known to be Greenhouse gases. and allows the use of alternative fuels such as corn oil, low-grade fuels, and even used motor oil. Bubble combustion is analogous to the inverse of spray combustion: the difference between bubble and spray combustion is that spray combustion is spraying a liquid in to a gas to form droplets, whereas bubble combustion involves injecting a gas into a liquid to form gaseous bubbles. In bubble combustion, the process for the ignition of the bubbles takes place on a time scale of less than a nanosecond and begins with acoustic waves perturbing each bubble. This perturbation causes the local pressure to drop below the vapor pressure of the liquid thus producing cavitation in which the bubble diameter grows, and upon reversal of the oscillating pressure field, the bubble then collapses rapidly with the aid of the high surface tension forces acting on the wall of the bubble. The rapid and violent collapse causes the temperatures inside the bubbles to soar as a result of adiabatic heating. As the temperatures rise, the gaseous contents of the bubble ignite with the bubble itself serving as its own combustion chamber. After ignition, this is the time in the bubble s life cycle where power is generated, and CO2, and NOx among other species, are produced. However, the pollutants CO2 and NOx are absorbed into the surrounding liquid. The importance of bubble combustion is that it generates power using a simple and compact device. We conducted a parametric study using CAVCHEM

  7. Biofuels combustion*

    DOE PAGES

    Westbrook, Charles K.

    2013-01-04

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acidsmore » and used primarily to replace or supplement conventional diesel fuels. As a result, research efforts on so-called second- and third-generation biofuels are discussed briefly.« less

  8. Turbulent combustion

    SciTech Connect

    Talbot, L.; Cheng, R.K.

    1993-12-01

    Turbulent combustion is the dominant process in heat and power generating systems. Its most significant aspect is to enhance the burning rate and volumetric power density. Turbulent mixing, however, also influences the chemical rates and has a direct effect on the formation of pollutants, flame ignition and extinction. Therefore, research and development of modern combustion systems for power generation, waste incineration and material synthesis must rely on a fundamental understanding of the physical effect of turbulence on combustion to develop theoretical models that can be used as design tools. The overall objective of this program is to investigate, primarily experimentally, the interaction and coupling between turbulence and combustion. These processes are complex and are characterized by scalar and velocity fluctuations with time and length scales spanning several orders of magnitude. They are also influenced by the so-called {open_quotes}field{close_quotes} effects associated with the characteristics of the flow and burner geometries. The authors` approach is to gain a fundamental understanding by investigating idealized laboratory flames. Laboratory flames are amenable to detailed interrogation by laser diagnostics and their flow geometries are chosen to simplify numerical modeling and simulations and to facilitate comparison between experiments and theory.

  9. Putting combustion optimization to work

    SciTech Connect

    Spring, N.

    2009-05-15

    New plants and plants that are retrofitting can benefit from combustion optimization. Boiler tuning and optimization can complement each other. The continuous emissions monitoring system CEMS, and tunable diode laser absorption spectroscopy TDLAS can be used for optimisation. NeuCO's CombustionOpt neural network software can determine optimal fuel and air set points. Babcock and Wilcox Power Generation Group Inc's Flame Doctor can be used in conjunction with other systems to diagnose and correct coal-fired burner performance. The four units of the Colstrip power plant in Colstrips, Montana were recently fitted with combustion optimization systems based on advanced model predictive multi variable controls (MPCs), ABB's Predict & Control tool. Unit 4 of Tampa Electric's Big Bend plant in Florida is fitted with Emerson's SmartProcess fuzzy neural model based combustion optimisation system. 1 photo.

  10. Multiuser Droplet Combustion Apparatus Developed to Conduct Combustion Experiments

    NASA Technical Reports Server (NTRS)

    Myhre, Craig A.

    2001-01-01

    A major portion of the energy produced in the world today comes from the combustion or burning of liquid hydrocarbon fuels in the form of droplets. However, despite vigorous scientific examinations for over a century, researchers still lack a full understanding of many fundamental combustion processes of liquid fuels. Understanding how these fuel droplets ignite, spread, and extinguish themselves will help us develop more efficient ways of energy production and propulsion, as well as help us deal better with the problems of combustion-generated pollution and fire hazards associated with liquid combustibles. The ability to conduct more controlled experiments in space, without the complication of gravity, provides scientists with an opportunity to examine these complicated processes closely. The Multiuser Droplet Combustion Apparatus (MDCA) supports this continued research under microgravity conditions. The objectives are to improve understanding of fundamental droplet phenomena affected by gravity, to use research results to advance droplet combustion science and technology on Earth, and to address issues of fire hazards associated with liquid combustibles on Earth and in space. MDCA is a multiuser facility designed to accommodate different combustion science experiments. The modular approach permits the on-orbit replacement of droplet combustion principal investigator experiments such as different fuels, droplet-dispensing needles, and droplet-tethering mechanisms. Large components such as the avionics, diagnostics, and base-plate remain on the International Space Station to reduce the launch mass of new experiments. MDCA is also designed to operate in concert with ground systems on Earth to minimize the involvement of the crew during orbit.

  11. Ducted whistlers propagating in higher-order guided mode and recorded on board of Compass-2 satellite by the advanced Signal Analyzer and Sampler 2

    NASA Astrophysics Data System (ADS)

    Ferencz, Orsolya E.; Bodnár, László; Ferencz, Csaba; Hamar, Dániel; Lichtenberger, János; Steinbach, Péter; Korepanov, Valery; Mikhaylova, Galina; Mikhaylov, Yuri; Kuznetsov, Vladimir

    2009-03-01

    The advanced electromagnetic wave detector and analyzer, Signal Analyzer and Sampler 2, successfully operated on board of Compass-2 satellite (launched May 2006). One of the peculiarities of this experiment was that the efficient sensitivities of both electric and magnetic channels were very close to being identical. Between the interesting events detected we found the evidence of whistler mode signals propagating in higher- (third-) order guided mode, most probable between two layers (i.e., ``onionskin'' structure was in the plasmasphere at this time). We present in the paper the real full wave ultrawideband interpretation of these propagating signals using the exact solution of Maxwell's equations in this boundary problem.

  12. Meteorological Satellites (METSAT) and Earth Observing System (EOS) Advanced Microwave Sounding Unit-A (AMSU-A) Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This Failure Modes and Effects Analysis (FMEA) is for the Advanced Microwave Sounding Unit-A (AMSU-A) instruments that are being designed and manufactured for the Meteorological Satellites Project (METSAT) and the Earth Observing System (EOS) integrated programs. The FMEA analyzes the design of the METSAT and EOS instruments as they currently exist. This FMEA is intended to identify METSAT and EOS failure modes and their effect on spacecraft-instrument and instrument-component interfaces. The prime objective of this FMEA is to identify potential catastrophic and critical failures so that susceptibility to the failures and their effects can be eliminated from the METSAT/EOS instruments.

  13. OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL

    SciTech Connect

    David R. Thompson; Lawrence E. Bool; Jack C. Chen

    2004-04-01

    concept offers substantial savings over SCR and is an economically attractive alternative to purchasing NOx credits or installing other conventional technologies. In conjunction with the development of oxygen based low NOx technology, Praxair also worked on developing the economically enhancing oxygen transport membrane (OTM) technology which is ideally suited for integration with combustion systems to achieve further significant cost reductions and efficiency improvements. This OTM oxygen production technology is based on ceramic mixed conductor membranes that operate at high temperatures and can be operated in a pressure driven mode to separate oxygen with infinite selectivity and high flux. An OTM material was selected and characterized. OTM elements were successfully fabricated. A single tube OTM reactor was designed and assembled. Testing of dense OTM elements was conducted with promising oxygen flux results of 100% of target flux. However, based on current natural gas prices and stand-alone air separation processes, ceramic membranes do not offer an economic advantage for this application. Under a different DOE-NETL Cooperative Agreement, Praxair is continuing to develop oxygen transport membranes for the Advanced Boiler where the economics appear more attractive.

  14. A hybrid 2-zone/WAVE engine combustion model for simulating combustion instabilities during dilute operation

    SciTech Connect

    Edwards, Kevin Dean; Wagner, Robert M; Chakravarthy, Veerathu K; Daw, C Stuart; Green Jr, Johney Boyd

    2006-01-01

    Internal combustion engines are operated under conditions of high exhaust gas recirculation (EGR) to reduce NO x emissions and promote enhanced combustion modes such as HCCI. However, high EGR under certain conditions also promotes nonlinear feedback between cycles, leading to the development of combustion instabilities and cyclic variability. We employ a two-zone phenomenological combustion model to simulate the onset of combustion instabilities under highly dilute conditions and to illustrate the impact of these instabilities on emissions and fuel efficiency. The two-zone in-cylinder combustion model is coupled to a WAVE engine-simulation code through a Simulink interface, allowing rapid simulation of several hundred successive engine cycles with many external engine parametric effects included. We demonstrate how this hybrid model can be used to study strategies for adaptive feedback control to reduce cyclic combustion instabilities and, thus, preserve fuel efficiency and reduce emissions.

  15. Regenerative combustion device

    DOEpatents

    West, Phillip B.

    2004-03-16

    A regenerative combustion device having a combustion zone, and chemicals contained within the combustion zone, such as water, having a first equilibrium state, and a second combustible state. Means for transforming the chemicals from the first equilibrium state to the second combustible state, such as electrodes, are disposed within the chemicals. An igniter, such as a spark plug or similar device, is disposed within the combustion zone for igniting combustion of the chemicals in the second combustible state. The combustion products are contained within the combustion zone, and the chemicals are selected such that the combustion products naturally chemically revert into the chemicals in the first equilibrium state following combustion. The combustion device may thus be repeatedly reused, requiring only a brief wait after each ignition to allow the regeneration of combustible gasses within the head space.

  16. Ramjet-Mode Operation in a Combined Cycle Engine Combustor

    NASA Astrophysics Data System (ADS)

    Kato, Kanenori; Kudo, Kenji; Murakami, Atsuo; Tani, Kouichiro; Kanda, Takeshi

    A rocket-ramjet combined-cycle engine was tested in ramjet-mode. The combustor model had two rockets in the combustor section. They were used as an igniter in this operation mode. In the preliminary tests, the downstream combustion ramjet-mode was demonstrated with a 1.4-degree of divergent duct condition. In this study, the upstream and downstream combustion ramjet-mode operations were applied to the combined cycle engine model with large angle of divergent duct condition. In the case of upstream combustion ramjet-mode, the combustion condition at the exit of the combustor showed high combustion efficiency.

  17. Cold tests and high power measurements on an advanced quasi-optical mode converter for a 118 GHz gyrotron

    SciTech Connect

    Braz, O.; Losert, M.; Moebius, A.; Thumm, M. |

    1995-12-31

    This paper reports on cold test and high power measurements of the improved, dimple type quasi-optical mode converter for the 118 GHz, 0.5 MW, 210 s TE{sub 22,6} gyrotron oscillator collaboratively developed by CEA Cadarache, CRPP Lausanne, FZK Karlsruhe and Thomson Tubes Electroniques Velizy. For the low power measurements the required rotating TE{sub 22,6} mode was generated in a coaxial cavity using quasioptical techniques. The high power measurements were performed on the gyrotron output beam using an infrared camera. The evaluated mode purity of the linearly polarized fundamental Gaussian output mode is (96 {plus_minus} 1)% in agreement with calculations.

  18. Effects of Fusion Zone Size and Failure Mode on Peak Load and Energy Absorption of Advanced High Strength Steel Spot Welds under Lap Shear Loading Conditions

    SciTech Connect

    Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2008-06-01

    This paper examines the effects of fusion zone size on failure modes, static strength and energy absorption of resistance spot welds (RSW) of advanced high strength steels (AHSS) under lap shear loading condition. DP800 and TRIP800 spot welds are considered. The main failure modes for spot welds are nugget pullout and interfacial fracture. Partial interfacial fracture is also observed. Static weld strength tests using lap shear samples were performed on the joint populations with various fusion zone sizes. The resulted peak load and energy absorption levels associated with each failure mode were studied for all the weld populations using statistical data analysis tools. The results in this study show that AHSS spot welds with conventionally required fusion zone size of can not produce nugget pullout mode for both the DP800 and TRIP800 welds under lap shear loading. Moreover, failure mode has strong influence on weld peak load and energy absorption for all the DP800 welds and the TRIP800 small welds: welds failed in pullout mode have statistically higher strength and energy absorption than those failed in interfacial fracture mode. For TRIP800 welds above the critical fusion zone level, the influence of weld failure modes on peak load and energy absorption diminishes. Scatter plots of peak load and energy absorption versus weld fusion zone size were then constructed, and the results indicate that fusion zone size is the most critical factor in weld quality in terms of peak load and energy absorption for both DP800 and TRIP800 spot welds.

  19. Effects of Fusion Zone Size on Failure Modes and Performance of Advanced High Strength Steel Spot Welds (2006-01-0531)

    SciTech Connect

    Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2007-03-01

    This paper examines the effects of fusion zone size on failure modes, static strength and energy absorption of resistance spot welds (RSW) of advanced high strength steels (AHSS). DP800 and TRIP800 spot welds are considered. The main failure modes for spot welds are nugget pullout and interfacial fracture. Partial interfacial fracture is also observed. The critical fusion zone sizes to ensure nugget pull-out failure mode are developed for both DP800 and TRIP800 using the limit load based analytical model and the micro-hardness measurements of the weld cross sections. Static weld strength tests using cross tension samples were performed on the joint populations with controlled fusion zone sizes. The resulted peak load and energy absorption levels associated with each failure mode were studied using statistical data analysis tools. The results in this study show that the conventional weld size of 4 t1/2 can not produce nugget pullout mode for both the DP800 and TRIP800 materials. The results also suggest that performance based spot weld acceptance criteria should be developed for different AHSS spot welds.

  20. Effects of Fusion Zone Size and Failure Mode on Peak Load and Energy Absorption of Advanced High Strength Steel Spot Welds

    SciTech Connect

    Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2007-01-01

    This paper examines the effects of fusion zone size on failure modes, static strength and energy absorption of resistance spot welds (RSW) of advanced high strength steels (AHSS). DP800 and TRIP800 spot welds are considered. The main failure modes for spot welds are nugget pullout and interfacial fracture. Partial interfacial fracture is also observed. The critical fusion zone sizes to ensure nugget pull-out failure mode are developed for both DP800 and TRIP800 using limit load based analytical model and micro-hardness measurements of the weld cross sections. Static weld strength tests using cross tension samples were performed on the joint populations with controlled fusion zone sizes. The resulted peak load and energy absorption levels associated with each failure mode were studied for all the weld populations using statistical data analysis tools. The results in this study show that AHSS spot welds with fusion zone size of can not produce nugget pullout mode for both the DP800 and TRIP800 materials examined. The critical fusion zone size for nugget pullout shall be derived for individual materials based on different base metal properties as well as different heat affected zone (HAZ) and weld properties resulted from different welding parameters.

  1. Light Duty Efficient, Clean Combustion

    SciTech Connect

    Donald Stanton

    2010-12-31

    Cummins has successfully completed the Light Duty Efficient Clean Combustion (LDECC) cooperative program with DoE. This program was established in 2007 in support of the Department of Energy's Vehicles Technologies Advanced Combustion and Emissions Control initiative to remove critical barriers to the commercialization of advanced, high efficiency, emissions compliant internal combustion (IC) engines for light duty vehicles. Work in this area expanded the fundamental knowledge of engine combustion to new regimes and advanced the knowledge of fuel requirements for these diesel engines to realize their full potential. All of the following objectives were met with fuel efficiency improvement targets exceeded: (1) Improve light duty vehicle (5000 lb. test weight) fuel efficiency by 10.5% over today's state-of-the-art diesel engine on the FTP city drive cycle; (2) Develop and design an advanced combustion system plus aftertreatment system that synergistically meets Tier 2 Bin 5 NOx and PM emissions standards while demonstrating the efficiency improvements; (3) Maintain power density comparable to that of current conventional engines for the applicable vehicle class; and (4) Evaluate different fuel components and ensure combustion system compatibility with commercially available biofuels. Key accomplishments include: (1) A 25% improvement in fuel efficiency was achieved with the advanced LDECC engine equipped with a novel SCR aftertreatment system compared to the 10.5% target; (2) An 11% improvement in fuel efficiency was achieved with the advanced LDECC engine and no NOx aftertreamtent system; (3) Tier 2 Bin 5 and SFTP II emissions regulations were met with the advanced LDECC engine equipped with a novel SCR aftertreatment system; (4) Tier 2 Bin 5 emissions regulations were met with the advanced LDECC engine and no NOx aftertreatment, but SFTP II emissions regulations were not met for the US06 test cycle - Additional technical barriers exist for the no NOx

  2. Combustion instability modeling and analysis

    SciTech Connect

    Santoro, R.J.; Yang, V.; Santavicca, D.A.; Sheppard, E.J.

    1995-12-31

    It is well known that the two key elements for achieving low emissions and high performance in a gas turbine combustor are to simultaneously establish (1) a lean combustion zone for maintaining low NO{sub x} emissions and (2) rapid mixing for good ignition and flame stability. However, these requirements, when coupled with the short combustor lengths used to limit the residence time for NO formation typical of advanced gas turbine combustors, can lead to problems regarding unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions, as well as the occurrence of combustion instabilities. The concurrent development of suitable analytical and numerical models that are validated with experimental studies is important for achieving this objective. A major benefit of the present research will be to provide for the first time an experimentally verified model of emissions and performance of gas turbine combustors. The present study represents a coordinated effort between industry, government and academia to investigate gas turbine combustion dynamics. Specific study areas include development of advanced diagnostics, definition of controlling phenomena, advancement of analytical and numerical modeling capabilities, and assessment of the current status of our ability to apply these tools to practical gas turbine combustors. The present work involves four tasks which address, respectively, (1) the development of a fiber-optic probe for fuel-air ratio measurements, (2) the study of combustion instability using laser-based diagnostics in a high pressure, high temperature flow reactor, (3) the development of analytical and numerical modeling capabilities for describing combustion instability which will be validated against experimental data, and (4) the preparation of a literature survey and establishment of a data base on practical experience with combustion instability.

  3. Fluids and Combustion Facility: Combustion Integrated Rack Modal Model Correlation

    NASA Technical Reports Server (NTRS)

    McNelis, Mark E.; Suarez, Vicente J.; Sullivan, Timothy L.; Otten, Kim D.; Akers, James C.

    2005-01-01

    The Fluids and Combustion Facility (FCF) is a modular, multi-user, two-rack facility dedicated to combustion and fluids science in the US Laboratory Destiny on the International Space Station. FCF is a permanent facility that is capable of accommodating up to ten combustion and fluid science investigations per year. FCF research in combustion and fluid science supports NASA's Exploration of Space Initiative for on-orbit fire suppression, fire safety, and space system fluids management. The Combustion Integrated Rack (CIR) is one of two racks in the FCF. The CIR major structural elements include the International Standard Payload Rack (ISPR), Experiment Assembly (optics bench and combustion chamber), Air Thermal Control Unit (ATCU), Rack Door, and Lower Structure Assembly (Input/Output Processor and Electrical Power Control Unit). The load path through the rack structure is outlined. The CIR modal survey was conducted to validate the load path predicted by the CIR finite element model (FEM). The modal survey is done by experimentally measuring the CIR frequencies and mode shapes. The CIR model was test correlated by updating the model to represent the test mode shapes. The correlated CIR model delivery is required by NASA JSC at Launch-10.5 months. The test correlated CIR flight FEM is analytically integrated into the Shuttle for a coupled loads analysis of the launch configuration. The analysis frequency range of interest is 0-50 Hz. A coupled loads analysis is the analytical integration of the Shuttle with its cargo element, the Mini Payload Logistics Module (MPLM), in the Shuttle cargo bay. For each Shuttle launch configuration, a verification coupled loads analysis is performed to determine the loads in the cargo bay as part of the structural certification process.

  4. Development and Validation of New Advanced Ocean Altimetry Products From Cryosat-2 in Conventional and in SAR Mode

    NASA Astrophysics Data System (ADS)

    Cotton, D.; Gommenginger, C.; Andersen, O. B.; Boy, F.; Cancet, M.; Egido, A.; Fernandes, J.; Moreau, T.; Naeije, M.; Garcia, P.; Dinardo, S.; Benveniste, J.

    2013-12-01

    The ESA CryoSat-2 mission is the first space mission to carry a radar altimeter that can operate in Synthetic Aperture Radar (SAR) mode, as well as the more conventional Low Rate Mode (LRM), and also the SAR Interferometric mode (SARIN). Although the prime mission objective of CryoSat-2 is to monitor land and marine ice, the SAR mode capability of the CryoSat-2 SIRAL altimeter also presents the opportunity of demonstrating significant potential benefits of SAR altimetry for ocean applications. Expected performance enhancements of SAR mode include improved range precision, finer along track spatial resolution, and an improved ability to provide measurements close to the coast. The 'Cryosat Plus for Oceans' (CP4O) project is supported by ESA under the Support To Science Element Programme. CP4O started in June 2012, and will continue to June 2014. The objectives of CP4O are: to build a sound scientific basis for new scientific and operational applications of CryoSat-2 data over the open ocean, polar ocean, coastal seas and for sea-floor mapping. to generate and evaluate new methods and products that will enable the full exploitation of the capabilities of the CryoSat-2 SIRAL altimeter, and extend their application beyond the initial mission objectives. to ensure that the scientific return of the CryoSat-2 mission is maximised. This work is being carried out within four sub-themes: Open Ocean Altimetry, Coastal Zone Altimetry, Polar Ocean Altimetry, and Sea Floor Altimetry. In this presentation we provide a detailed assessment of the capability of SAR altimeter data to provide improved oceanographic measurements over the open ocean, coastal ocean and polar ocean. We describe different processing schemes applied to Cryosat-2 SAR mode data, to carry out full resolution SAR processing and SAR mode retracking, and to construct LRM-type altimeter waveforms from the SAR bursts, - so called Reduced SAR mode (RDSAR). The latter processing is important to determine if it is

  5. DEVELOPMENT OF A NOVEL RADIATIVELY/CONDUCTIVELY STABILIZED BURNER FOR SIGNIFICANT REDUCTION OF NOx EMISSIONS AND FOR ADVANCING THE MODELING AND UNDERSTANDING OF PULVERIZED COAL COMBUSTION AND EMISSIONS

    SciTech Connect

    Noam Lior; Stuart W. Churchill

    2003-10-01

    The primary objective of the proposed study was the study and analysis of, and design recommendations for, a novel radiatively-conductively stabilized combustion (RCSC) process for pulverized coal, which, based on our prior studies with both fluid fuels and pulverized coal, holds a high promise to reduce NO{sub x} production significantly. We have primarily engaged in continuing and improving our process modeling and analysis, obtained a large amount of quantitative information about the effects of the major parameters on NO{sub x} production, conducted an extensive exergy analysis of the process, evaluated the practicalities of employing the Radiatively-Conductively Stabilized Combustor (RCSC) to large power and heat plants, and improved the experimental facility. Prior experimental work has proven the feasibility of the combustor, but slagging during coal combustion was observed and should be dealt with. The primary outcomes and conclusions from the study are: (1) we developed a model and computer program that represents the pulverized coal combustion in the RCSC, (2) the model predicts that NO{sub x} emissions can be reduced by a number of methods, detailed in the report. (3) the exergy analysis points out at least a couple of possible ways to improve the exergetic efficiency in this combustor: increasing the effectiveness of thermal feedback, and adjusting the combustor mixture exit location, (4) because of the low coal flow rates necessitated in this study to obtain complete combustion in the burner, the size of a burner operating under the considered conditions would have to be up to an order of magnitude, larger than comparable commercial burners, but different flow configurations of the RCSC can yield higher feed rates and smaller dimensions, and should be investigated. Related to this contract, eleven papers were published in journals and conference proceedings, and ten invited presentations were given at university and research institutions, as well as at

  6. Development of a Premixed Combustion Capability for Scramjet Combustion Experiments

    NASA Technical Reports Server (NTRS)

    Rockwell, Robert D.; Goyne, Christopher P.; Rice, Brian E.; Chelliah, Harsha; McDaniel, James C.; Edwards, Jack R.; Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Danehy, Paul M.

    2015-01-01

    Hypersonic air-breathing engines rely on scramjet combustion processes, which involve high speed, compressible, and highly turbulent flows. The combustion environment and the turbulent flames at the heart of these engines are difficult to simulate and study in the laboratory under well controlled conditions. Typically, wind-tunnel testing is performed that more closely approximates engine testing rather than a careful investigation of the underlying physics that drives the combustion process. The experiments described in this paper, along with companion data sets being developed separately, aim to isolate the chemical kinetic effects from the fuel-air mixing process in a dual-mode scramjet combustion environment. A unique fuel injection approach is taken that produces a nearly uniform fuel-air mixture at the entrance to the combustor. This approach relies on the precombustion shock train upstream of the dual-mode scramjet combustor. A stable ethylene flame anchored on a cavity flameholder with a uniformly mixed combustor inflow has been achieved in these experiments allowing numerous companion studies involving coherent anti-Stokes Raman scattering (CARS), particle image velocimetry (PIV), and planar laser induced fluorescence (PLIF) to be performed.

  7. Fuel gas combustion research at METC

    SciTech Connect

    Norton, T.S.

    1995-06-01

    The in-house combustion research program at METC is an integral part of many METC activities, providing support to METC product teams, project managers, and external industrial and university partners. While the majority of in-house combustion research in recent years has been focussed on the lean premixed combustion of natural gas fuel for Advanced Turbine Systems (ATS) applications, increasing emphasis is being placed on issues of syngas combustion, as the time approaches when the ATS and coal-fired power systems programs will reach convergence. When the METC syngas generator is built in 1996, METC will have the unique combination of mid-scale pressurized experimental facilities, a continuous syngas supply with variable ammonia loading, and a team of people with expertise in low-emissions combustion, chemical kinetics, combustion modeling, combustion diagnostics, and the control of combustion instabilities. These will enable us to investigate such issues as the effects of pressure, temperature, and fuel gas composition on the rate of conversion of fuel nitrogen to NOx, and on combustion instabilities in a variety of combustor designs.

  8. Impact of E × B flow shear on turbulence and resulting power fall-off width in H-mode plasmas in experimental advanced superconducting tokamak

    SciTech Connect

    Yang, Q. Q. Zhong, F. C. E-mail: fczhong@dhu.edu.cn; Jia, M. N.; Xu, G. S. E-mail: fczhong@dhu.edu.cn; Wang, L.; Wang, H. Q.; Chen, R.; Yan, N.; Liu, S. C.; Chen, L.; Li, Y. L.; Liu, J. B.

    2015-06-15

    The power fall-off width in the H-mode scrape-off layer (SOL) in tokamaks shows a strong inverse dependence on the plasma current, which was noticed by both previous multi-machine scaling work [T. Eich et al., Nucl. Fusion 53, 093031 (2013)] and more recent work [L. Wang et al., Nucl. Fusion 54, 114002 (2014)] on the Experimental Advanced Superconducting Tokamak. To understand the underlying physics, probe measurements of three H-mode discharges with different plasma currents have been studied in this work. The results suggest that a higher plasma current is accompanied by a stronger E×B shear and a shorter radial correlation length of turbulence in the SOL, thus resulting in a narrower power fall-off width. A simple model has also been applied to demonstrate the suppression effect of E×B shear on turbulence in the SOL and shows relatively good agreement with the experimental observations.

  9. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Third quarterly technical progress report

    SciTech Connect

    Not Available

    1993-12-31

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. Baseline, AOFA, LNB, and LNB plus AOFA test segments have been completed. Analysis of the 94 days of LNB long-term data collected show the full-load NO{sub x} emission levels to be approximately 0.65 lb/MBtu with fly ash LOI values of approximately 8 percent. Corresponding values for the AOFA configuration are 0.94 lb/MBtu and approximately 10 percent. For comparison, the long-term full-load, baseline NO{sub x} emission level was approximately 1.24 lb/MBtu at 5.2 percent LOI. Comprehensive testing in the LNB+AOFA configuration indicate that at full-load, NO{sub x} emissions and fly ash LOI are near 0.40 lb/MBtu and 8 percent, respectively. However, it is believed that a substantial portion of the incremental change in NO{sub x} emissions between the LNB and LNB+AOFA configurations is the result of additional burner tuning and other operational adjustments and is not the result of the AOFA system. During this quarter, LNB+AOFA testing was concluded. Testing performed during this quarter included long-term and verification testing in the LNB+AOFA configuration.

  10. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Third quarterly progress report, 1992: Innovative Clean Coal Technology (ICCT)

    SciTech Connect

    Not Available

    1992-12-31

    The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulatecharacteristics and boiler efficiency. Baseline, AOFA, and LNB without AOFA test segments have been completed. Analysis of the 94 days of LNB long-term data collected show the full-load NO{sub x} emission levels to be approximately 0.65 lb/MBtu. Flyash LOI values for the LNB configuration are approximately 8 percent at full-load. Corresponding values for the AOFA configuration are 0.94 lb/MBtu and approximately 10 percent. Abbreviated diagnostic tests for the LNB+AOFA configuration indicate that at 500 MWe, NO{sub x} emissions are approximately 0.55 lb/MBtu with corresponding flyash LOI values of approximately 11 percent. For comparison, the long-term full-load, baseline NO{sub x} emission level was approximately 1.24 lb/MBtu at 5.2 percent LOI. Comprehensive testing of the LNB+AOFA configuration will be performed when the stackparticulate emissions issue is resolved. Testing of a process optimization package on Plant Hammond Unit 4 was performed during this quarter. The software was configured to minimize NO{sub x} emissions using total combustion air flow and advanced overfire air distribution as the controlled parameters. Preliminary results from this testing indicate that this package shows promise in reducing NO{sub x} emissions while maintaining or improving other boiler performance parameters.

  11. Combustion chemistry

    SciTech Connect

    Brown, N.J.

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  12. Final CRADA Report ORNL-00-0609, Real-Time Control of Diesel Combustion Quality

    SciTech Connect

    Wagner, Robert M

    2010-07-01

    Detroit Diesel Corporation (DDC) and ORNL established this CRADA to improve heavy-duty engine efficiency with reduced emissions at relatively extreme operating regimes such has high EGR, low-load, and cold-start, with an emphasis on the application of advanced control strategies. The approach used in this collaborative effort was to include the application of novel analysis and modeling techniques developed from the application of nonlinear dynamics and chaos theory. More specifically, analytical techniques derived from these theories were to used to detect, characterize, and control the combustion instabilities that are responsible for poor combustion performance and corresponding high emissions. The foundation of this CRADA was established based on ORNL expertise on the fundamentals of advanced combustion operation and experience with nonlinear dynamics and controls in combustion systems. The initial plan was all data generation would be performed at DDC with an agreed upon experimental plan formed by both organizations. While numerous experiments were performed at DDC and the data was exchanged with ORNL researchers, the team decided to transfer an engine to ORNL to allow more flexibility and data generation opportunities. A prototype DDC Series 60 with a common rail fuel system was selected and installed at ORNL. DDC and ORNL maintained a strong collaboration throughout much of this project. Direct funding from DOE ended in 2004 and DDC continued to fund at a reduced amount through 2007. This CRADA has not been funded in more recent years but has been maintained active in anticipation of restored funding. This CRADA has led to additional collaborations between DDC and ORNL. The objectives are to: (1) Explore and establish boundaries of high efficiency clean combustion (HECC) modes on a DDC heavy-duty diesel engine; (2) Improve fundamental understanding of combustion instabilities for use in the development of predictive controls and diagnostics; and (3) Develop

  13. JANNAF 37th Combustion Subcommittee Meeting. Volume 1

    NASA Technical Reports Server (NTRS)

    Fry, Ronald S. (Editor); Gannaway, Mary T. (Editor)

    2000-01-01

    This volume, the first of two volumes is a compilation of 59 unclassified/unlimited-distribution technical papers presented at the Joint Army-Navy-NASA-Air Force (JANNAF) 37th Combustion Subcommittee (CS) meeting held jointly with the 25th Airbreathing Propulsion Subcommittee (APS), 19th Propulsion Systems Hazards Subcommittee (PSHS), and 1st Modeling and Simulation Subcommittee (MSS) meetings. The meeting was held 13-17 November 2000 at the Naval Postgraduate School and Hyatt Regency Hotel, Monterey, California. Topics covered at the CS meeting include: a keynote address on the Future Combat Systems, and review of a new JANNAF Modeling and Simulation Subcommittee, and technical papers on gun propellant burning rate, gun tube erosion, advanced gun propulsion concepts, ETC guns, novel gun propellants; liquid, hybrid and novel propellant combustion; solid propellant combustion kinetics, GAP, ADN and RDX combustion, sandwich combustion, metal combustion, combustion instability, and motor combustion instability.

  14. MO-DE-202-02: Advances in Image Registration and Reconstruction for Image-Guided Neurosurgery.

    PubMed

    Siewerdsen, J

    2016-06-01

    At least three major trends in surgical intervention have emerged over the last decade: a move toward more minimally invasive (or non-invasive) approach to the surgical target; the development of high-precision treatment delivery techniques; and the increasing role of multi-modality intraoperative imaging in support of such procedures. This symposium includes invited presentations on recent advances in each of these areas and the emerging role for medical physics research in the development and translation of high-precision interventional techniques. The four speakers are: (1) Keyvan Farahani, "Image-guided focused ultrasound surgery and therapy" (2) Jeffrey H. Siewerdsen, "Advances in image registration and reconstruction for image-guided neurosurgery" (3) Tina Kapur, "Image-guided surgery and interventions in the advanced multimodality image-guided operating (AMIGO) suite" (4) Raj Shekhar, "Multimodality image-guided interventions: Multimodality for the rest of us" Learning Objectives: 1. Understand the principles and applications of HIFU in surgical ablation. 2. Learn about recent advances in 3D-2D and 3D deformable image registration in support of surgical safety and precision. 3. Learn about recent advances in model-based 3D image reconstruction in application to intraoperative 3D imaging. 4. Understand the multi-modality imaging technologies and clinical applications investigated in the AMIGO suite. 5. Understand the emerging need and techniques to implement multi-modality image guidance in surgical applications such as neurosurgery, orthopaedic surgery, vascular surgery, and interventional radiology. Research supported by the NIH and Siemens Healthcare.; J. Siewerdsen; Grant Support - National Institutes of Health; Grant Support - Siemens Healthcare; Grant Support - Carestream Health; Advisory Board - Carestream Health; Licensing Agreement - Carestream Health; Licensing Agreement - Elekta Oncology.; T. Kapur, P41EB015898; R. Shekhar, Funding: R42CA137886 and

  15. Combustible particluate fuel heater

    SciTech Connect

    Collins, B.H.; Jurgens, H.J.W.

    1986-01-21

    This patent describes a combustible particulate fired heater. It consists of: a combustion chamber defined by upright side walls extending between open top and bottom ends; an enclosure surrounding the combustion chamber; a retort within the combustion chamber adjacent the bottom end and having a lower particulate receiving end and an upper open end; feed conveyor means leading through the enclosure to the retort for delivering metered quantities of combustible particulates to the lower particulate receiving end of the retort; primary combustion air supply means having a primary combustion air supply manifold extending at least partially about the upper open end of the retort; primary air control means on the primary air supply means for selectively allowing entry of combustion air from outside the enclosure in to the retort; secondary combustion air supply means including a secondary air supply manifold within the combustion chamber above the primary combustion air supply manifold; secondary air control means independent of the primary air control means for selectively allowing entry of secondary air from outside the enclosure to an area within the combustion chamber above the retort; an exhaust duct opening into the enclosure; and vacuum means connected to the exhaust duct for producing a pressure differential between the area confined by the enclosure and the ambient atmosphere such that ambient air is drawn through at least one of the combustion air supply means to induce a high level of gasification and to support combustion at the retort and for drawing combustion exhaust gases out through the exhaust duct.

  16. Assessment of the National Combustion Code

    NASA Technical Reports Server (NTRS)

    Liu, nan-Suey; Iannetti, Anthony; Shih, Tsan-Hsing

    2007-01-01

    The advancements made during the last decade in the areas of combustion modeling, numerical simulation, and computing platform have greatly facilitated the use of CFD based tools in the development of combustion technology. Further development of verification, validation and uncertainty quantification will have profound impact on the reliability and utility of these CFD based tools. The objectives of the present effort are to establish baseline for the National Combustion Code (NCC) and experimental data, as well as to document current capabilities and identify gaps for further improvements.

  17. Combustion technologies

    SciTech Connect

    Barsin, J.A.

    1994-12-31

    The presentation will cover the highlights of sludge, providing information as to where it comes from, projection of how much more is expected, what is sludge, what can be done with them, and finally focus in one combustion technology that can be utilized and applied to recycle sludge. The author is with Gotaverken Energy Systems Inc. where for the past 100 years they have been involved in the recovery of chemicals in chemical pulp mills. One week ago, our name was changed to Kvaerner Pulping Inc. to better reflect our present make-up which is a combination of Kamyr AB (suppliers of proprietary highly engineered totally chlorine free chemical pulp manufacturing systems, including digesters, O{sub 2} delignification systems, and bleach plant systems) and Goetaverken. Sludges that we are concerned with derive from several sources within chemical pulp mills such as: such as primary clarifier sludges, secondary clarifier sludges, and most recently those sludges derived from post consumer paper and board recycle efforts including de-inking and those from the thermal mechanical pulping processes. These sludges have been classified as non-hazardous therefore, residue can be landfilled, but the volumes involved are growing at an alarming rate.

  18. ABB Combustion Engineering nuclear technology

    SciTech Connect

    Matzie, R.A.

    1994-12-31

    The activities of ABB Combustion Engineering in the design and construction of nuclear systems and components are briefly reviewed. ABB Construction Engineering continues to improve the design and design process for nuclear generating stations. Potential improvements are evaluated to meet new requirements both of the public and the regulator, so that the designs meet the highest standards worldwide. Advancements necessary to meet market needs and to ensure the highest level of performance in the future will be made.

  19. The large-amplitude combustion oscillation in a single-side expansion scramjet combustor

    NASA Astrophysics Data System (ADS)

    Ouyang, Hao; Liu, Weidong; Sun, Mingbo

    2015-12-01

    The combustion oscillation in scramjet combustor is believed not existing and ignored for a long time. Compared with the flame pulsation, the large-amplitude combustion oscillation in scramjet combustor is indeed unfamiliar and difficult to be observed. In this study, the specifically designed experiments are carried out to investigate this unusual phenomenon in a single-side expansion scramjet combustor. The entrance parameter of combustor corresponds to scramjet flight Mach number 4.0 with a total temperature of 947 K. The obtained results show that the large-amplitude combustion oscillation can exist in scramjet combustor, which is not occasional and can be reproduced. Under the given conditions of this study, moreover, the large-amplitude combustion oscillation is regular and periodic, whose principal frequency is about 126 Hz. The proceeding of the combustion oscillation is accompanied by the transformation of the flame-holding pattern and combustion mode transition between scramjet mode combustion and ramjet mode combustion.

  20. Advanced methodology for measuring the extensive elastic compliance and mechanical loss directly in k31 mode piezoelectric ceramic plates

    NASA Astrophysics Data System (ADS)

    Majzoubi, Maryam; Shekhani, Husain N.; Bansal, Anushka; Hennig, Eberhard; Scholehwar, Timo; Uchino, Kenji

    2016-12-01

    Dielectric, elastic, and piezoelectric constants, and their corresponding losses are defined under constant conditions of two categories; namely, intensive (i.e., E, electric field or T, stress), and extensive (i.e., D, dielectric displacement or x, strain) ones. So far, only the intensive parameters and losses could be measured directly in a k31 mode sample. Their corresponding extensive parameters could be calculated indirectly using the coupling factor and "K" matrix. However, the extensive loss parameters, calculated through this indirect method, could have large uncertainty, due to the error propagation in calculation. In order to overcome this issue, extensive losses should be measured separately from the measurable intensive ones in lead-zirconate-titanate (PZT) k31 mode rectangular plate ceramics. We propose a new mechanical-excitation methodology, using a non-destructive testing approach by means of a partial electrode configuration, instead of the conventional full electrode configuration. For this purpose, a non-electrode sample was prepared, where the electrode covered only 10% of the top and bottom surfaces at the center to actuate the whole sample, and also monitor the responding vibration. The admittance spectrum of this sample, corresponds to PZT properties under dielectric displacement D constant condition. Furthermore, ceramics with partial-electrodes were also prepared to create short and open circuit boundary conditions, attributing to resonance and anti-resonance modes. In the proposed way, we were able to measure both intensive and extensive elastic compliances and mechanical losses directly for the first time. The accuracy of this new method is compared with the conventional measurements by use of indirect calculations. The preliminary results (by neglecting the 10% actuator part difference at this point) were obtained, which were in good agreements (less than 3% difference) with the previous indirect method.

  1. Mixed mode control method and engine using same

    DOEpatents

    Kesse, Mary L.; Duffy, Kevin P.

    2007-04-10

    A method of mixed mode operation of an internal combustion engine includes the steps of controlling a homogeneous charge combustion event timing in a given engine cycle, and controlling a conventional charge injection event to be at least a predetermined time after the homogeneous charge combustion event. An internal combustion engine is provided, including an electronic controller having a computer readable medium with a combustion timing control algorithm recorded thereon, the control algorithm including means for controlling a homogeneous charge combustion event timing and means for controlling a conventional injection event timing to be at least a predetermined time from the homogeneous charge combustion event.

  2. Engineering and Economic Analysis of an Advanced Ultra-Supercritical Pulverized Coal Power Plant with and without Post-Combustion Carbon Capture Task 7. Design and Economic Studies

    SciTech Connect

    Booras, George; Powers, J.; Riley, C.; Hendrix, H.

    2015-09-01

    This report evaluates the economics and performance of two A-USC PC power plants; Case 1 is a conventionally configured A-USC PC power plant with superior emission controls, but without CO2 removal; and Case 2 adds a post-combustion carbon capture (PCC) system to the plant from Case 1, using the design and heat integration strategies from EPRI’s 2015 report, “Best Integrated Coal Plant.” The capture design basis for this case is “partial,” to meet EPA’s proposed New Source Performance Standard, which was initially proposed as 500 kg-CO2/MWh (gross) or 1100 lb-CO2/MWh (gross), but modified in August 2015 to 635 kg-CO2/MWh (gross) or 1400 lb-CO2/MWh (gross). This report draws upon the collective experience of consortium members, with EPRI and General Electric leading the study. General Electric provided the steam cycle analysis as well as v the steam turbine design and cost estimating. EPRI performed integrated plant performance analysis using EPRI’s PC Cost model.

  3. 180 MW demonstration of advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Final report

    SciTech Connect

    Tavoulareas, E.S.; Hardman, R.; Eskinazi, D.; Smith, L.

    1994-02-01

    This report provides the key findings of the Innovative Clean Coal Technology (ICCT) demonstration project at Gulf Power`s Lansing Smith Unit No. 2 and the implications for other tangentially-fired boilers. L. Smith Unit No. 2 is a 180 MW tangentially-fired boiler burning Eastern Bituminous coal, which was retrofitted with Asea Brown Boveri/Combustion Engineering Services` (ABB/CE) LNCFS I, II, and III technologies. An extensive test program was carried-out with US Department of Energy, Southern Company and Electric Power Research Institute (EPRI) funding. The LNCFS I, II, and III achieved 37 percent, 37 percent, and 45 percent average long-term NO{sub x} emission reduction at full load, respectively (see following table). Similar NO{sub x} reduction was achieved within the control range (100--200 MW). However, below the control point (100 MW), NO{sub x} emissions with the LNCFS technologies increased significantly, reaching pre-retrofit levels at 70 MW. Short-term testing proved that low load NO{sub x} emissions could be reduced further by using lower excess O{sub 2} and burner tilt, but with adversed impacts on unit performance, such as lower steam outlet temperatures and, potentially, higher CO emissions and LOI.

  4. Innovative Clean Coal Technology (ICCT): 180 MW demonstration of advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Topical report, LNCFS Levels 1 and 3 test results

    SciTech Connect

    Not Available

    1993-08-17

    This report presents results from the third phase of an Innovative Clean Coal Technology (ICC-1) project demonstrating advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from a coal-fired boiler. The purpose of this project was to study the NO{sub x} emissions characteristics of ABB Combustion Engineering`s (ABB CE) Low NO{sub x} Concentric Firing System (LNCFS) Levels I, II, and III. These technologies were installed and tested in a stepwise fashion at Gulf Power Company`s Plant Lansing Smith Unit 2. The objective of this report is to provide the results from Phase III. During that phase, Levels I and III of the ABB C-E Services Low NO{sub x} Concentric Firing System were tested. The LNCFS Level III technology includes separated overfire air, close coupled overfire air, clustered coal nozzles, flame attachment coal nozzle tips, and concentric firing. The LNCFS Level I was simulated by closing the separated overfire air nozzles of the LNCFS Level III system. Based upon long-term data, LNCFS Level HI reduced NO{sub x} emissions by 45 percent at full load. LOI levels with LNCFS Level III increased slightly, however, tests showed that LOI levels with LNCFS Level III were highly dependent upon coal fineness. After correcting for leakage air through the separated overfire air system, the simulated LNCFS Level I reduced NO{sub x} emissions by 37 percent. There was no increase in LOI with LNCFS Level I.

  5. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal fired boilers. Second quarterly technical progress report, [April--June 1993

    SciTech Connect

    Not Available

    1993-12-31

    The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. Baseline, AOFA, and LNB without AOFA test segments have been completed. Analysis of the 94 days of LNB long-term data collected show the full-load NO{sub x} emission levels to be approximately 0.65 lb/MBtu with flyash LOI values of approximately 8 percent. Corresponding values for the AOFA configuration are 0.94 lb/MBtu and approximately 10 percent. For comparison, the long-term full-load, baseline NO{sub x} emission level was approximately 1.24 lb/MBtu at 5.2 percent LOI. Comprehensive testing of the LNB plus AOFA configuration began in May 1993 and is scheduled to end during August 1993. As of June 30, the diagnostic, performance, chemical emissions tests segments for this configuration have been conducted and 29 days of long-term, emissions data collected. Preliminary results from the May--June 1993 tests of the LNB plus AOFA system show that the full load NO{sub x} emissions are approximately 0.42 lb/MBtu with corresponding fly ash LOI values near 8 percent. This is a substantial improvement in both NO{sub x} emissions and LOI values when compared to the results obtained during the February--March 1992 abbreviated testing of this system.

  6. Optimizing Low Temperature Diesel Combustion (LTC-D) "FreedomCAR and Vehicle Technologies Program Solicitation for University Research and Graduate Automotice Technology Education (GATE) Centers of Excellence"

    SciTech Connect

    Rolf Reitz; P. Farrell; D. Foster; J. Ghandhi; C. Rutland; S. Sanders

    2009-07-31

    The engine industry is currently facing severe emissions mandates. Pollutant emissions from mobile sources are a major source of concern. For example, US EPA mandates require emissions of particulate and nitrogen oxides (NOx) from heavy-duty diesel engine exhaust to drop at least 90 percent between 1998 and 2010. Effective analysis of the combustion process is required to guide the selection of technologies for future development since exhaust after-treatment solutions are not currently available that can meet the required emission reduction goals. The goal of this project is to develop methods to optimize and control Low Temperature Combustion Diesel technologies (LTC-D) that offers the potential of nearly eliminating engine NOx and particulate emissions at reduced cost over traditional methods by controlling pollutant emissions in-cylinder. The work was divided into 5 Tasks, featuring experimental and modeling components: 1.) Fundamental understanding of LTC-D and advanced model development, 2.) Experimental investigation of LTC-D combustion control concepts, 3.) Application of detailed models for optimization of LTC-D combustion and emissions, 4.) Impact of heat transfer and spray impingement on LTC-D combustion, and 5.) Transient engine control with mixed-mode combustion. As described in the final report (December 2008), outcomes from the research included providing guidelines to the engine and energy industries for achieving optimal low temperature combustion operation through using advanced fuel injection strategies, and the potential to extend low temperature operation through manipulation of fuel characteristics. In addition, recommendations were made for improved combustion chamber geometries that are matched to injection sprays and that minimize wall fuel films. The role of fuel-air mixing, fuel characteristics, fuel spray/wall impingement and heat transfer on LTC-D engine control were revealed. Methods were proposed for transient engine operation during

  7. Fundamentals of Gas Turbine combustion

    NASA Technical Reports Server (NTRS)

    Gerstein, M.

    1979-01-01

    Combustion problems and research recommendations are discussed in the areas of atomization and vaporization, combustion chemistry, combustion dynamics, and combustion modelling. The recommendations considered of highest priority in these areas are presented.

  8. Recent advances in elementary flux modes and yield space analysis as useful tools in metabolic network studies.

    PubMed

    Horvat, Predrag; Koller, Martin; Braunegg, Gerhart

    2015-09-01

    A review of the use of elementary flux modes (EFMs) and their applications in metabolic engineering covered with yield space analysis (YSA) is presented. EFMs are an invaluable tool in mathematical modeling of biochemical processes. They are described from their inception in 1994, followed by various improvements of their computation in later years. YSA constitutes another precious tool for metabolic network modeling, and is presented in details along with EFMs in this article. The application of these techniques is discussed for several case studies of metabolic network modeling provided in respective original articles. The article is concluded by some case studies in which the application of EFMs and YSA turned out to be most useful, such as the analysis of intracellular polyhydroxyalkanoate (PHA) formation and consumption in Cupriavidus necator, including the constraint-based description of the steady-state flux cone of the strain's metabolic network, the profound analysis of a continuous five-stage bioreactor cascade for PHA production by C. necator using EFMs and, finally, the study of metabolic fluxes in the metabolic network of C. necator cultivated on glycerol.

  9. Advanced analytical method of nereistoxin using mixed-mode cationic exchange solid-phase extraction and GC/MS.

    PubMed

    Park, Yujin; Choe, Sanggil; Lee, Heesang; Jo, Jiyeong; Park, Yonghoon; Kim, Eunmi; Pyo, Jaesung; Jung, Jee H

    2015-07-01

    Nereistoxin(NTX) was originated from a marine annelid worm Lumbriconereis heteropoda and its analogue pesticides including cartap, bensultap, thiocyclam and thiobensultap have been commonly used in agriculture, because of their low toxicity and high insecticidal activity. However, NTX has been reported about its inhibitory neuro toxicity in human and animal body, by blocking nicotinic acetylcholine receptor and it cause significant neuromuscular toxicity, resulting in respiratory failure. We developed a new method to determine NTX in biological fluid. The method involves mixed-mode cationic exchange based solid phase extraction and gas chromatography/mass spectrometry for final identification and quantitative analysis. The limit of detection and recovery were substantially better than those of other methods using liquid-liquid extraction or headspace solid phase microextraction. The good recoveries (97±14%) in blood samples were obtained and calibration curves over the range 0.05-20 mg/L have R2 values greater than 0.99. The developed method was applied to a fatal case of cartap intoxication of 74 years old woman who ingested cartap hydrochloride for suicide. Cartap and NTX were detected from postmortem specimens and the cause of the death was ruled to be nereistoxin intoxication. The concentrations of NTX were 2.58 mg/L, 3.36 mg/L and 1479.7 mg/L in heart, femoral blood and stomach liquid content, respectively. The heart blood/femoral blood ratio of NTX was 0.76.

  10. Flameless Combustion Workshop

    DTIC Science & Technology

    2005-09-20

    future roadmap. "Flameless Combustion " is characterized by high stability levels with virtually no thermoacoustic instabilities, very low lean... future roadmap. "Flameless Combustion " is characterized by high stability levels with virtually no thermoacoustic instabilities, very low lean stability...C. Bruno, Italy 1430-1500 Technology to Ramjet Combustion Application of FLameless H. Mongia , GE Transportation, 1500-1530 Combustion (FLC) for

  11. Advanced manufacturing technologies for reduced cost and weight in portable ruggedized VIS-IR and multi-mode optical systems for land, sea, and air

    NASA Astrophysics Data System (ADS)

    Sweeney, Michael; Spinazzola, Robert; Morrison, Donald; Macklin, Dennis; Marion, Jared

    2011-06-01

    Homeland security systems, special forces, unmanned aerial vehicles (UAV), and marine patrols require low cost, high performance, multi-mode visible through infrared (VIS-IR) wavelength optical systems to identify and neutralize potential threats that often arise at long ranges and under poor visibility conditions. Long range and wide spectral performance requirements favor reflective optical system design solutions. The limited field of view of such designs can be significantly enhanced by the use of catadioptric optical solutions that utilize molded or diamond point machined VIS-IR lenses downstream from reflective objective optics. A common optical aperture that services multiple modes of field-of-view, operating wavelength, and includes laser ranging and spotting, provides the highest utility and is most ideal for size and weight. Such a design also often requires fast, highly aspheric, reflective, refractive, and sometimes diffractive surfaces using high performance and aggressively light-weighted materials that demand the finest of manufacturing technologies. Visible wavelength performance sets the bar for component optical surface irregularity on the order of 20 nm RMS and surface finishes less than 3.0 nm RMS. Aluminum mirrors and structures can also be precision machined to yield "snap together alignment" or limited compensation assembly approaches to reduce cost and enhance interchangeability. Diamond point turning, die cast and investment cast mirror substrates and structures, computerized optical polishing, mirror replication, lens molding and other advanced manufacturing technologies can all be used to minimize the cost of this type of optical equipment. This paper discusses the tradeoffs among materials and process selection for catadioptric, multi-mode systems that are under development for a variety of DoD and Homeland Security applications. Several examples are profiled to illuminate the confluence of applicable design and manufacturing

  12. FDNS CFD Code Benchmark for RBCC Ejector Mode Operation

    NASA Technical Reports Server (NTRS)

    Holt, James B.; Ruf, Joe

    1999-01-01

    Computational Fluid Dynamics (CFD) analysis results are compared with benchmark quality test data from the Propulsion Engineering Research Center's (PERC) Rocket Based Combined Cycle (RBCC) experiments to verify fluid dynamic code and application procedures. RBCC engine flowpath development will rely on CFD applications to capture the multi-dimensional fluid dynamic interactions and to quantify their effect on the RBCC system performance. Therefore, the accuracy of these CFD codes must be determined through detailed comparisons with test data. The PERC experiments build upon the well-known 1968 rocket-ejector experiments of Odegaard and Stroup by employing advanced optical and laser based diagnostics to evaluate mixing and secondary combustion. The Finite Difference Navier Stokes (FDNS) code was used to model the fluid dynamics of the PERC RBCC ejector mode configuration. Analyses were performed for both Diffusion and Afterburning (DAB) and Simultaneous Mixing and Combustion (SMC) test conditions. Results from both the 2D and the 3D models are presented.

  13. Mechanisms of droplet combustion

    NASA Technical Reports Server (NTRS)

    Law, C. K.

    1982-01-01

    The fundamental physico-chemical mechanisms governing droplet vaporization and combustion are discussed. Specific topics include governing equations and simplifications, the classical d(2)-Law solution and its subsequent modification, finite-rate kinetics and the flame structure, droplet dynamics, near- and super-critical combustion, combustion of multicomponent fuel blends/emulsions/suspensions, and droplet interaction. Potential research topics are suggested.

  14. High Efficiency, Clean Combustion

    SciTech Connect

    Donald Stanton

    2010-03-31

    challenges to reduce oil consumption and greenhouse gases, meet stringent emissions regulations, provide customer value, and improve safety. The HECC program successfully reduced engine fuel consumption and greenhouse gases while providing greater customer valve. The US EPA 2010 emissions standard poses a significant challenge for developing clean diesel powertrains that meet the DoE Vehicle Technologies Multi-Year Program Plan (MYPP) for fuel efficiency improvement while remaining affordable. Along with exhaust emissions, an emphasis on heavy duty vehicle fuel efficiency is being driven by increased energy costs as well as the potential regulation of greenhouse gases. An important element of the success of meeting emissions while significantly improving efficiency is leveraging Cummins component technologies such as fuel injection equipment, aftertreatment, turbomahcinery, electronic controls, and combustion systems. Innovation in component technology coupled with system integration is enabling Cummins to move forward with the development of high efficiency clean diesel products with a long term goal of reaching a 55% peak brake thermal efficiency for the engine plus aftertreatment system. The first step in developing high efficiency clean products has been supported by the DoE co-sponsored HECC program. The objectives of the HECC program are: (1) To design and develop advanced diesel engine architectures capable of achieving US EPA 2010 emission regulations while improving the brake thermal efficiency by 10% compared to the baseline (a state of the art 2007 production diesel engine). (2) To design and develop components and subsystems (fuel systems, air handling, controls, etc) to enable construction and development of multi-cylinder engines. (3) To perform an assessment of the commercial viability of the newly developed engine technology. (4) To specify fuel properties conducive to improvements in emissions, reliability, and fuel efficiency for engines using high

  15. Pulsating combustion of gas fuel in the combustion chamber with closed resonant circuit

    NASA Astrophysics Data System (ADS)

    Yallina, E. V.; Larionov, V. M.; Iovleva, O. V.

    2013-12-01

    In the combustion chambers of the pulsation of gas flow oscillation greatly accelerate heat dissipation to the walls of the combustion chamber and improve combustion efficiency as compared with a uniform combustion mode. This allows you to effectively solve a number of problems of industrial power, including an environmentally friendly combustion products. Significant drawback of such systems - the emitted noise exceeding the permissible requirements. One solution to this problem - the separation of the resonance tube into 2 parts connected at the output to the interference of sound waves. The results of theoretical studies pulsating combustion technical mixture of propane in the system, consisting of a combustion chamber and two resonance tubes forming a closed resonant circuit. Resonators have a variable length. Calculations have shown that under certain oscillation of the resonator length to the first resonant frequency of the system is achieved by reducing SPL more than 15 dB. For oscillations at a second resonant frequency is the complete elimination of noise while maintaining intense oscillations in the combustion chamber.

  16. Modeling complex chemical effects in turbulent nonpremixed combustion

    NASA Technical Reports Server (NTRS)

    Smith, Nigel S. A.

    1995-01-01

    Virtually all of the energy derived from the consumption of combustibles occurs in systems which utilize turbulent fluid motion. Since combustion is largely related to the mixing of fluids and mixing processes are orders of magnitude more rapid when enhanced by turbulent motion, efficiency criteria dictate that chemically powered devices necessarily involve fluid turbulence. Where combustion occurs concurrently with mixing at an interface between two reactive fluid bodies, this mode of combustion is called nonpremixed combustion. This is distinct from premixed combustion where flame-fronts propagate into a homogeneous mixture of reactants. These two modes are limiting cases in the range of temporal lag between mixing of reactants and the onset of reaction. Nonpremixed combustion occurs where this lag tends to zero, while premixed combustion occurs where this lag tends to infinity. Many combustion processes are hybrids of these two extremes with finite non-zero lag times. Turbulent nonpremixed combustion is important from a practical standpoint because it occurs in gas fired boilers, furnaces, waste incinerators, diesel engines, gas turbine combustors, and afterburners etc. To a large extent, past development of these practical systems involved an empirical methodology. Presently, efficiency standards and emission regulations are being further tightened (Correa 1993), and empiricism has had to give way to more fundamental research in order to understand and effectively model practical combustion processes (Pope 1991). A key element in effective modeling of turbulent combustion is making use of a sufficiently detailed chemical kinetic mechanism. The prediction of pollutant emission such as oxides of nitrogen (NO(x)) and sulphur (SO(x)) unburned hydrocarbons, and particulates demands the use of detailed chemical mechanisms. It is essential that practical models for turbulent nonpremixed combustion are capable of handling large numbers of 'stiff' chemical species

  17. Advanced bioreactor concepts for gaseous substrates: Conversion of synthesis gas to liquid fuels and removal of SO{sub x} and NO{sub x} from coal combustion gases. CRADA final report

    SciTech Connect

    Kaufman, E.N.; Selvaraj, P.T.

    1997-10-01

    The purpose of the proposed research program was the development and demonstration of a new generation of gaseous substrate-based bioreactors for the production of liquid fuels from coal synthesis gas and the removal of NO{sub x} and SO{sub x} species from coal combustion flue gas. This study addressed the further investigation of optimal bacterial strains, growth media and kinetics for the biocatalytic conversion of coal synthesis gas to liquid fuel such as ethanol and the reduction of gaseous flue gas constituents. The primary emphasis was on the development of advanced bioreactor systems coupled with innovative biocatalytic systems that will provide increased productivity under controlled conditions. It was hoped that this would result in bioprocessing options that have both technical and economic feasibility, thus, ensuring early industrial use. Predictive mathematical models were formulated to accommodate hydrodynamics, mass transport, and conversion kinetics, and provide the data base for design and scale-up. The program was separated into four tasks: (1) Optimization of Biocatalytic Kinetics; (2) Development of Well-mixed and Columnar Reactors; (3) Development of Predictive Mathematical Models; and (4) Industrial Demonstration. Research activities addressing both synthesis gas conversion and flue gas removal were conducted in parallel by BRI and ORNL respectively.

  18. Hydrogen-oxygen powered internal combustion engine

    NASA Technical Reports Server (NTRS)

    Cameron, H.; Morgan, N.

    1970-01-01

    Hydrogen at 300 psi and oxygen at 800 psi are injected sequentially into the combustion chamber to form hydrogen-rich mixture. This mode of injection eliminates difficulties of preignition, detonation, etc., encountered with carburated, spark-ignited, hydrogen-air mixtures. Ignition at startup is by means of a palladium catalyst.

  19. A review of the Mark 48-F, 3.50 pitch diameter, 2-stage reaction turbine designed for the staged combustion cycle requirements of an advanced space engine

    NASA Technical Reports Server (NTRS)

    Macaluso, S. B.

    1976-01-01

    The Mark 48-F two-stage reaction turbine was designed as a component for an advanced space engine propellant feed system, high-pressure liquid hydrogen turbopump. The turbine total inlet temperature and total inlet pressure were designed to be 1860 R and 3420 psia, respectively. At a design speed of 95,000 rpm, the turbine will develop 2543 horsepower with LO2/LH2 working fluid. The aerothermodynamic performance of a prototype turbine assembly was evaluated with gaseous nitrogen working fluid. Turbine performance was evaluated at turbine velocity ratios ranging from 0.250 to 0.782, and turbine speeds up to 25,250 rpm. Turbine test efficiency at the design velocity ratio of 0.483 was found to be 79.5% total-to-total.

  20. 2014 Princeton-CEFRC Summer School on Combustion

    DTIC Science & Technology

    2014-11-20

    develop a validated, predictive, multi-scale, combustion modeling capability to optimize the design and operation of evolving fuels, especially biofuels ...optimize the design and operation of evolving fuels, especially biofuels , in advanced engines for transportation applications. The Summer School...validated, predictive, multi-scale, combustion modeling capability to optimize the design and operation of evolving fuels, especially biofuels , in

  1. Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions

    DOEpatents

    Biruduganti, Munidhar S.; Gupta, Sreenath Borra; Sekar, R. Raj; McConnell, Steven S.

    2008-11-25

    A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.

  2. Pulsed atmospheric fluidized bed combustion

    SciTech Connect

    Not Available

    1989-11-01

    In order to verify the technical feasibility of the MTCI Pulsed Atmospheric Fluidized Bed Combustor technology, a laboratory-scale system was designed, built and tested. Important aspects of the operational and performance parameters of the system were established experimentally. A considerable amount of the effort was invested in the initial task of constructing an AFBC that would represent a reasonable baseline against which the performance of the PAFBC could be compared. A summary comparison of the performance and emissions data from the MTCI 2 ft {times} 2 ft facility (AFBC and PAFBC modes) with those from conventional BFBC (taller freeboard and recycle operation) and circulating fluidized bed combustion (CFBC) units is given in Table ES-1. The comparison is for typical high-volatile bituminous coals and sorbents of average reactivity. The values indicated for BFBC and CFBC were based on published information. The AFBC unit that was designed to act as a baseline for the comparison was indeed representative of the larger units even at the smaller scale for which it was designed. The PAFBC mode exhibited superior performance in relation to the AFBC mode. The higher combustion efficiency translates into reduced coal consumption and lower system operating cost; the improvement in sulfur capture implies less sorbent requirement and waste generation and in turn lower operating cost; lower NO{sub x} and CO emissions mean ease of site permitting; and greater steam-generation rate translates into less heat exchange surface area and reduced capital cost. Also, the PAFBC performance generally surpasses those of conventional BFBC, is comparable to CFBC in combustion and NO{sub x} emissions, and is better than CFBC in sulfur capture and CO emissions even at the scaled-down size used for the experimental feasibility tests.

  3. Indirect combustion noise of auxiliary power units

    NASA Astrophysics Data System (ADS)

    Tam, Christopher K. W.; Parrish, Sarah A.; Xu, Jun; Schuster, Bill

    2013-08-01

    Recent advances in noise suppression technology have significantly reduced jet and fan noise from commercial jet engines. This leads many investigators in the aeroacoustics community to suggest that core noise could well be the next aircraft noise barrier. Core noise consists of turbine noise and combustion noise. There is direct combustion noise generated by the combustion processes, and there is indirect combustion noise generated by the passage of combustion hot spots, or entropy waves, through constrictions in an engine. The present work focuses on indirect combustion noise. Indirect combustion noise has now been found in laboratory experiments. The primary objective of this work is to investigate whether indirect combustion noise is also generated in jet and other engines. In a jet engine, there are numerous noise sources. This makes the identification of indirect combustion noise a formidable task. Here, our effort concentrates exclusively on auxiliary power units (APUs). This choice is motivated by the fact that APUs are relatively simple engines with only a few noise sources. It is, therefore, expected that the chance of success is higher. Accordingly, a theoretical model study of the generation of indirect combustion noise in an Auxiliary Power Unit (APU) is carried out. The cross-sectional areas of an APU from the combustor to the turbine exit are scaled off to form an equivalent nozzle. A principal function of a turbine in an APU is to extract mechanical energy from the flow stream through the exertion of a resistive force. Therefore, the turbine is modeled by adding a negative body force to the momentum equation. This model is used to predict the ranges of frequencies over which there is a high probability for indirect combustion noise generation. Experimental spectra of internal pressure fluctuations and far-field noise of an RE220 APU are examined to identify anomalous peaks. These peaks are possible indirection combustion noise. In the case of the

  4. An extended multi-zone combustion model for PCI simulation

    NASA Astrophysics Data System (ADS)

    Kodavasal, Janardhan; Keum, SeungHwan; Babajimopoulos, Aristotelis

    2011-12-01

    Novel combustion modes are becoming an important area of research with emission regulations more stringent than ever before, and with fuel economy being assigned greater importance every day. Homogeneous Charge Compression Ignition (HCCI) and Premixed Compression Ignition (PCI) modes in particular promise better fuel economy and lower emissions in internal combustion engines. Multi-zone combustion models have been popular in modelling HCCI combustion. In this work, an improved multi-zone model is suggested for PCI combustion modelling. A new zoning scheme is suggested based on incorporating the internal energy of formation into an earlier conventional HCCI multi-zone approach, which considers a two-dimensional reaction space defined by equivalence ratio and temperature. It is shown that the added dimension improves zoning by creating more representative zones, and thus reducing errors compared to the conventional zoning approach, when applied to PCI simulation.

  5. A Study of Advanced Materials for Gas Turbine Coatings at Elevated Temperatures Using Selected Microstructures and Characteristic Environments for Syngas Combustion

    SciTech Connect

    Ravinder Diwan; Patrick Mensah; Guoqiang Li; Nalini Uppu; Strphen Akwaboa; Monica Silva; Ebubekir Beyazoglu; Ogad Agu; Naresh Polasa; Lawrence Bazille; Douglas Wolfe; Purush Sahoo

    2011-02-10

    Thermal barrier coatings (TBCs) that can be suitable for use in industrial gas turbine engines have been processed and compared with electron beam physical vapor deposition (EBPVD) microstructures for applications in advanced gas turbines that use coal-derived synthesis gas. Thermo-physical properties have been evaluated of the processed air plasma sprayed TBCs with standard APS-STD and vertically cracked APS-VC coatings samples up to 1300 C. Porosity of these selected coatings with related microstructural effects have been analyzed in this study. Wet and dry thermal cycling studies at 1125 C and spalling resistance thermal cycling studies to 1200 C have also been carried out. Type I and Type II hot corrosion tests were carried out to investigate the effects of microstructure variations and additions of alumina in YSZ top coats in multi-layered TBC structures. The thermal modeling of turbine blade has also been carried out that gives the capability to predict in-service performance temperature gradients. In addition to isothermal high temperature oxidation kinetics analysis in YSZ thermal barrier coatings of NiCoCrAlY bond coats with 0.25% Hf. This can affect the failure behavior depending on the control of the thermally grown oxide (TGO) growth at the interface. The TGO growth kinetics is seen to be parabolic and the activation energies correspond to interfacial growth kinetics that is controlled by the diffusion of O{sub 2} in Al{sub 2}O{sub 3}. The difference between oxidation behavior of the VC and STD structures are attributed to the effects of microstructure morphology and porosity on oxygen ingression into the zirconia and TGO layers. The isothermal oxidation resistance of the STD and VC microstructures is similar at temperatures up to 1200 C. However, the generally thicker TGO layer thicknesses and the slightly faster oxidation rates in the VC microstructures are attributed to the increased ingression of oxygen through the grain boundaries of the vertically

  6. Coal combustion science. Quarterly progress report, April 1993--June 1993

    SciTech Connect

    Hardesty, D.R.

    1994-05-01

    This document is a quarterly status report of the Coal Combustion Science Project that is being conducted at the Combustion Research Facility, Sandia National Laboratories. The information reported is for Apr-Jun 1993. The objective of this work is to support the Office of Fossil Energy in executing research on coal combustion science. This project consists of basic research on coal combustion that supports both the PETC Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency Coal Combustion Science Project. The objective of the kinetics and mechanisms of pulverized coal char combustion task is to characterize the combustion behavior of selected US coals under conditions relevant to industrial pulverized coal-fired furnaces. Work is being done in four areas: kinetics of heterogeneous fuel particle populations; char combustion kinetics at high carbon conversion; the role of particle structure and the char formation process in combustion and; unification of the Sandia char combustion data base. This data base on the high temperature reactivities of chars from strategic US coals will permit identification of important fuel-specific trends and development of predictive capabilities for advanced coal combustion systems. The objective of the fate of inorganic material during coal combustion task is the establish a quantitative understanding of the mechanisms and rates of transformation, fragmentation, and deposition of inorganic material during coal combustion as a function of coal type, particle size and temperature, the initial forms and distribution of inorganic species in the unreacted coal, and the local gas temperature and composition. In addition, optical diagnostic capabilities are being developed for in situ, real-time detection of inorganic vapor species and surface species during ash deposition. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  7. Opportunities in pulse combustion

    SciTech Connect

    Brenchley, D.L.; Bomelburg, H.J.

    1985-10-01

    In most pulse combustors, the combustion occurs near the closed end of a tube where inlet valves operate in phase with the pressure amplitude variations. Thus, within the combustion zone, both the temperature and the pressure oscillate around a mean value. However, the development of practical applications of pulse combustion has been hampered because effective design requires the right combination of the combustor's dimensions, valve characteristics, fuel/oxidizer combination, and flow pattern. Pulse combustion has several additional advantages for energy conversion efficiency, including high combustion and thermal efficiency, high combustion intensity, and high convective heat transfer rates. Also, pulse combustion can be self-aspirating, generating a pressure boost without using a blower. This allows the use of a compact heat exchanger that may include a condensing section and may obviate the need for a chimney. In the last decade, these features have revived interest in pulse combustion research and development, which has resulted in the development of a pulse combustion air heater by Lennox, and a pulse combustion hydronic unit by Hydrotherm, Inc. To appraise this potential for energy savings, a systematic study was conducted of the many past and present attempts to use pulse combustion for practical purposes. The authors recommended areas where pulse combustion technology could possibly be applied in the future and identified areas in which additional R and D would be necessary. Many of the results of the study project derived from a special workshop on pulse combustion. This document highlights the main points of the study report, with particular emphasis on pulse combustion application in chemical engineering.

  8. Promoted Combustion Test Data Re-Examined

    NASA Technical Reports Server (NTRS)

    Lewis, Michelle; Jeffers, Nathan; Stoltzfus, Joel

    2010-01-01

    Promoted combustion testing of metallic materials has been performed by NASA since the mid-1980s to determine the burn resistance of materials in oxygen-enriched environments. As the technolo gy has advanced, the method of interpreting, presenting, and applying the promoted combustion data has advanced as well. Recently NASA changed the bum criterion from 15 cm (6 in.) to 3 cm (1.2 in.). This new burn criterion was adopted for ASTM G 124, Standard Test Method for Determining the Combustion Behavior- of Metallic Materials in Oxygen-Enriched Atmospheres. Its effect on the test data and the latest method to display the test data will be discussed. Two specific examples that illustrate how this new criterion affects the burn/no-bum thresholds of metal alloys will also be presented.

  9. Low-rank coal research: Volume 3, Combustion research: Final report. [Great Plains

    SciTech Connect

    Mann, M. D.; Hajicek, D. R.; Zobeck, B. J.; Kalmanovitch, D. P.; Potas, T. A.; Maas, D. J.; Malterer, T. J.; DeWall, R. A.; Miller, B. G.; Johnson, M. D.

    1987-04-01

    Volume III, Combustion Research, contains articles on fluidized bed combustion, advanced processes for low-rank coal slurry production, low-rank coal slurry combustion, heat engine utilization of low-rank coals, and Great Plains Gasification Plant. These articles have been entered individually into EDB and ERA. (LTN)

  10. Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion

    SciTech Connect

    Ojeda, William de

    2010-07-31

    The project which extended from November 2005 to May of 2010 demonstrated the application of Low Temperature Combustion (LTC) with engine out NOx levels of 0.2 g/bhp-hr throughout the program target load of 12.6bar BMEP. The project showed that the range of loads could be extended to 16.5bar BMEP, therefore matching the reference lug line of the base 2007 MY Navistar 6.4L V8 engine. Results showed that the application of LTC provided a dramatic improvement over engine out emissions when compared to the base engine. Furthermore LTC improved thermal efficiency by over 5% from the base production engine when using the steady state 13 mode composite test as a benchmark. The key enablers included improvements in the air, fuel injection, and cooling systems made in Phases I and II. The outcome was the product of a careful integration of each component under an intelligent control system. The engine hardware provided the conditions to support LTC and the controller provided the necessary robustness for a stable combustion. Phase III provided a detailed account on the injection strategy used to meet the high load requirements. During this phase, the control strategy was implemented in a production automotive grade ECU to perform cycle-by-cycle combustion feedback on each of the engine cylinders. The control interacted on a cycle base with the injection system and with the Turbo-EGR systems according to their respective time constants. The result was a unique system that could, first, help optimize the combustion system and maintain high efficiency, and secondly, extend the steady state results to the transient mode of operation. The engine was upgraded in Phase IV with a Variable Valve Actuation system and a hybrid EGR loop. The impact of the more versatile EGR loop did not provide significant advantages, however the application of VVA proved to be an enabler to further extend the operation of LTC and gain considerable benefits in fuel economy and soot reduction. Finally

  11. LES Modeling of Supersonic Combustion at SCRAMJET Conditions

    NASA Astrophysics Data System (ADS)

    Vane, Zachary; Lacaze, Guilhem; Oefelein, Joseph

    2016-11-01

    Results from a series of large-eddy simulations (LES) of the Hypersonic International Flight Research Experiment (HIFiRE) are examined with emphasis placed on the coupled performance of the wall and combustion models. The test case of interest corresponds to the geometry and conditions found in the ground based experiments performed in the HIFiRE Direct Connect Rig (HDCR) in dual-mode operation. In these calculations, the turbulence and mixing characteristics of the high Reynolds number turbulent boundary layer with multi-species fuel injection are analyzed using a simplified chemical model and combustion closure to predict the heat release measured experimentally. These simulations are then used to identify different flame regimes in the combustor section. Concurrently, the performance of an equilibrium wall-model is evaluated in the vicinity of the fuel injectors and in the flame-holding cavity where regions of boundary layer and thermochemical non-equilibrium are present. Support for this research was provided by the Defense Advanced Research Projects Agency (DARPA).

  12. Putative model for heat shock protein 70 complexation with receptor of advanced glycation end products through fluorescence proximity assays and normal mode analyses.

    PubMed

    Grunwald, Marcelo Sartori; Ligabue-Braun, Rodrigo; Souza, Cristiane Santos; Heimfarth, Luana; Verli, Hugo; Gelain, Daniel Pens; Moreira, José Cláudio Fonseca

    2017-01-01

    Extracellular heat shock protein 70 (HSP70) is recognized by receptors on the plasma membrane, such as Toll-like receptor 4 (TLR4), TLR2, CD14, and CD40. This leads to activation of nuclear factor-kappa B (NF-κB), release of pro-inflammatory cytokines, enhancement of the phagocytic activity of innate immune cells, and stimulation of antigen-specific responses. However, the specific characteristics of HSP70 binding are still unknown, and all HSP70 receptors have not yet been described. Putative models for HSP70 complexation to the receptor for advanced glycation endproducts (RAGEs), considering both ADP- and ATP-bound states of HSP70, were obtained through molecular docking and interaction energy calculations. This interaction was detected and visualized by a proximity fluorescence-based assay in A549 cells and further analyzed by normal mode analyses of the docking complexes. The interacting energy of the complexes showed that the most favored docking situation occurs between HSP70 ATP-bound and RAGE in its monomeric state. The fluorescence proximity assay presented a higher number of detected spots in the HSP70 ATP treatment, corroborating with the computational result. Normal-mode analyses showed no conformational deformability in the interacting interface of the complexes. Results were compared with previous findings in which oxidized HSP70 was shown to be responsible for the differential modulation of macrophage activation, which could result from a signaling pathway triggered by RAGE binding. Our data provide important insights into the characteristics of HSP70 binding and receptor interactions, as well as putative models with conserved residues on the interface area, which could be useful for future site-directed mutagenesis studies.

  13. Combustion modeling in internal combustion engines

    NASA Technical Reports Server (NTRS)

    Zeleznik, F. J.

    1976-01-01

    The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

  14. Boiler using combustible fluid

    DOEpatents

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  15. Potential Commercial Applications from Combustion and Fire Research in Space

    NASA Technical Reports Server (NTRS)

    Friedman, Robert; Lyons, Valerie J.

    1996-01-01

    The near-zero (microgravity) environment of orbiting spacecraft minimizes buoyant flows, greatly simplifying combustion processes and isolating important phenomena ordinarily concealed by the overwhelming gravity-driven forces and flows. Fundamental combustion understanding - the focus to date of the NASA microgravity-combustion program - has greatly benefited from analyses and experiments conducted in the microgravity environment. Because of the economic and commercial importance of combustion in practice, there is strong motivation to seek wider applications for the microgravity-combustion findings. This paper reviews selected technology developments to illustrate some emerging applications. Topics cover improved fire-safety technology in spacecraft and terrestrial systems, innovative combustor designs for aerospace and ground propulsion, applied sensors and controls for combustion processes, and self-sustaining synthesis techniques for advanced materials.

  16. Active Combustion Control for Aircraft Gas Turbine Engines

    NASA Technical Reports Server (NTRS)

    DeLaat, John C.; Breisacher, Kevin J.; Saus, Joseph R.; Paxson, Daniel E.

    2000-01-01

    Lean-burning combustors are susceptible to combustion instabilities. Additionally, due to non-uniformities in the fuel-air mixing and in the combustion process, there typically exist hot areas in the combustor exit plane. These hot areas limit the operating temperature at the turbine inlet and thus constrain performance and efficiency. Finally, it is necessary to optimize the fuel-air ratio and flame temperature throughout the combustor to minimize the production of pollutants. In recent years, there has been considerable activity addressing Active Combustion Control. NASA Glenn Research Center's Active Combustion Control Technology effort aims to demonstrate active control in a realistic environment relevant to aircraft engines. Analysis and experiments are tied to aircraft gas turbine combustors. Considerable progress has been shown in demonstrating technologies for Combustion Instability Control, Pattern Factor Control, and Emissions Minimizing Control. Future plans are to advance the maturity of active combustion control technology to eventual demonstration in an engine environment.

  17. Combustion of interacting droplet arrays in a microgravity environment

    NASA Technical Reports Server (NTRS)

    Dietrich, Daniel L.

    1995-01-01

    This research program involves the study of one and two dimensional arrays of droplets in a buoyant-free environment. The purpose of the work is to extend the database and theories that exist for single droplets into the regime where droplet interactions are important. The eventual goal being to use the results of this work as inputs to models on spray combustion where droplets seldom burn individually; instead the combustion history of a droplet is strongly influenced by the presence of the neighboring droplets. Throughout the course of the work, a number of related aspects of isolated droplet combustion have also been investigated. This paper will review our progress in microgravity droplet array combustion, advanced diagnostics (specifically L2) applied to isolated droplet combustion, and radiative extinction large droplet flames. A small-scale droplet combustion experiment being developed for the Space Shuttle will also be described.

  18. Measurement and analysis of combustion response to transverse combustion instability

    NASA Astrophysics Data System (ADS)

    Pomeroy, Brian R.

    This research aimed to gain a better understanding of the response of a gas-centered swirl coaxial injector to transverse combustion instability. The goals of the research were to develop a combustion chamber that would be able to spontaneously produce transverse combustion instability at elevated pressures and temperatures. Methods were also developed to analyze high-speed video images to understand the response of the injector. A combustion chamber was designed that produced high levels of instabilities. The chamber was capable of pressures as high as 1034 kPa (150 psi) and operated using decomposed 90% hydrogen peroxide and JP-8. The chamber used an array of seven gas-centered swirl coaxial injectors that exhibited linear instability to drive the transverse oscillations. The injector elements would operate in a monopropellant configuration flowing only decomposed hydrogen peroxide or in a bipropellant configuration. The location of the bipropellant injectors could be varied to change the level of the instability in the chamber from 10% of the chamber pressure up to 70% of the chamber pressure. A study element was placed in the center of the chamber where it was observed simultaneously by two high-speed video cameras which recorded a backlit video to show the location of the fuel spray and the location of the emitted CH* chemiluminescence. The videos were synchronized with high frequency pressure measurements to gain a full understanding of the physics in the combustion chamber. Results showed that the study element was coupled with the first mode velocity wave. This was expected due to the first mode velocity anti-node being located in the center of the chamber. The velocity is an absolute maximum twice during each cycle so the coupling with the second mode pressure was also investigated showing a possible coupling with both the velocity and pressure. The results of the first mode velocity showed that, as the velocity wave traveled through the chamber, the fuel

  19. Combustion dynamics in liquid rocket engines

    NASA Technical Reports Server (NTRS)

    Mclain, W. H.

    1971-01-01

    A chemical analysis of the emission and absorption spectra in the combustion chamber of a nitrogen tetroxide/aerozine-50 rocket engine was conducted. Measurements were made under conditions of preignition, ignition, and post combustion operating periods. The cause of severe ignition overpressures sporadically observed during the vacuum startup of the Apollo reaction control system engine was investigated. The extent to which residual propellants or condensed intermediate reaction products remain after the engine has been operated in a pulse mode duty cycle was determined.

  20. Priorities for Microgravity Combustion Research and Goals for Workshop Discussions

    NASA Technical Reports Server (NTRS)

    Faeth, Gerard M.

    1993-01-01

    Several concerns motivate fundamental research: combustion-generated pollutants are re-emerging as a major problem, new combustion technologies are needed for effective energy utilization, municipal and hazardous waste incineration are needed to replace landfills and storage, new combustion technologies are needed for advanced aircraft and spacecraft propulsion systems, and current understanding of fires and explosion hazards is limited - particularly for space-craft environments. Thus, it is of interest to determine how experimentation using microgravity facilities can advance research relevant to these problems.

  1. Lump wood combustion process

    NASA Astrophysics Data System (ADS)

    Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

    2014-08-01

    The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

  2. Combustion instability modeling and analysis

    SciTech Connect

    Santoro, R.J.; Yang, V.; Santavicca, D.A.

    1995-10-01

    It is well known that the two key elements for achieving low emissions and high performance in a gas turbine combustor are to simultaneously establish (1) a lean combustion zone for maintaining low NO{sub x} emissions and (2) rapid mixing for good ignition and flame stability. However, these requirements, when coupled with the short combustor lengths used to limit the residence time for NO formation typical of advanced gas turbine combustors, can lead to problems regarding unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions, as well as the occurrence of combustion instabilities. Clearly, the key to successful gas turbine development is based on understanding the effects of geometry and operating conditions on combustion instability, emissions (including UHC, CO and NO{sub x}) and performance. The concurrent development of suitable analytical and numerical models that are validated with experimental studies is important for achieving this objective. A major benefit of the present research will be to provide for the first time an experimentally verified model of emissions and performance of gas turbine combustors.

  3. Fuels Combustion Research.

    DTIC Science & Technology

    1984-07-18

    uncertainties in the future sources and characteristics of fuels has emphasized the need to better understand fuel effects on combustion , e.g. energy release...experimentally to be made. Unsuccessful comparisons can lead to impro- vements in modelling concepts . Two simplified models for the combustion of slurry...AD-A149 186 FUELS COMBUSTION RESEACCH(U) PRINCETON UNIV NJ DEPT OF i/i MECHANICAL AND AEROSPACE ENGINEERING F L DRYER ET AL. 18 JUL 84 NAE-i668 AFOSR

  4. Coal combustion products

    USGS Publications Warehouse

    Kalyoncu, R.S.; Olson, D.W.

    2001-01-01

    Coal-burning powerplants, which supply more than half of U.S. electricity, also generate coal combustion products, which can be both a resource and a disposal problem. The U.S. Geological Survey collaborates with the American Coal Ash Association in preparing its annual report on coal combustion products. This Fact Sheet answers questions about present and potential uses of coal combustion products.

  5. A low-noise transimpedance amplifier for the detection of "Violin-Mode" resonances in advanced Laser Interferometer Gravitational wave Observatory suspensions

    NASA Astrophysics Data System (ADS)

    Lockerbie, N. A.; Tokmakov, K. V.

    2014-11-01

    This paper describes the design and performance of an extremely low-noise differential transimpedance amplifier, which takes its two inputs from separate photodiodes. The amplifier was planned to serve as the front-end electronics for a highly sensitive shadow-displacement sensing system, aimed at detecting very low-level "Violin-Mode" (VM) oscillations in 0.4 mm diameter by 600 mm long fused-silica suspension fibres. Four such highly tensioned fibres support the 40 kg test-masses/mirrors of the Advanced Laser Interferometer Gravitational wave Observatory interferometers. This novel design of amplifier incorporates features which prevent "noise-gain peaking" arising from large area photodiode (and cable) capacitances, and which also usefully separate the DC and AC photocurrents coming from the photodiodes. In consequence, the differential amplifier was able to generate straightforwardly two DC outputs, one per photodiode, as well as a single high-gain output for monitoring the VM oscillations—this output being derived from the difference of the photodiodes' two, naturally anti-phase, AC photocurrents. Following a displacement calibration, the amplifier's final VM signal output was found to have an AC displacement responsivity at 500 Hz of (9.43 ± 1.20) MV(rms) m-1(rms), and, therefore, a shot-noise limited sensitivity to such AC shadow- (i.e., fibre-) displacements of (69 ± 13) picometres/√Hz at this frequency, over a measuring span of ±0.1 mm.

  6. A low-noise transimpedance amplifier for the detection of "Violin-Mode" resonances in Advanced Laser Interferometer Gravitational wave Observatory suspensions.

    PubMed

    Lockerbie, N A; Tokmakov, K V

    2014-11-01

    This paper describes the design and performance of an extremely low-noise differential transimpedance amplifier, which takes its two inputs from separate photodiodes. The amplifier was planned to serve as the front-end electronics for a highly sensitive shadow-displacement sensing system, aimed at detecting very low-level "Violin-Mode" (VM) oscillations in 0.4 mm diameter by 600 mm long fused-silica suspension fibres. Four such highly tensioned fibres support the 40 kg test-masses/mirrors of the Advanced Laser Interferometer Gravitational wave Observatory interferometers. This novel design of amplifier incorporates features which prevent "noise-gain peaking" arising from large area photodiode (and cable) capacitances, and which also usefully separate the DC and AC photocurrents coming from the photodiodes. In consequence, the differential amplifier was able to generate straightforwardly two DC outputs, one per photodiode, as well as a single high-gain output for monitoring the VM oscillations-this output being derived from the difference of the photodiodes' two, naturally anti-phase, AC photocurrents. Following a displacement calibration, the amplifier's final VM signal output was found to have an AC displacement responsivity at 500 Hz of (9.43 ± 1.20) MV(rms) m(-1)(rms), and, therefore, a shot-noise limited sensitivity to such AC shadow- (i.e., fibre-) displacements of (69 ± 13) picometres/√Hz at this frequency, over a measuring span of ±0.1 mm.

  7. Optimization on the Thickness of Organic Insulator Layer for Advanced Super-In-Plane Switching Mode Thin-Film-Transistor Liquid Crystal Displays

    NASA Astrophysics Data System (ADS)

    Lin, Jiunn-Shyong; Yang, Kei-Hsiung; Chen, Shu-Hsia

    2005-08-01

    The growth rate of thin-film-transistor liquid crystal display (TFT-LCD) industries is faster than predicted due to the possible replacement of a cathode-ray tube television (CRT-TV) by a liquid crystal display television (LCD-TV). The in-plane switching (IPS) mode has been known as an excellent technology for realizing a wide viewing angle for LCD-TV, but it has the drawback of a low aperture ratio. An advanced super-IPS (AS-IPS) structure with an organic insulator layer was invented to achieve a high aperture ratio with increasing manufacturing cost. In this paper, we proposed a simple method of analyzing the optimum thickness of the organic insulator layer for AS-IPS. We derived the capacitive coupling ratio (CCR) of the IPS cell and analyzed the delay time of the AS-IPS panel to quantify the crosstalk properties. Furthermore, we also analyzed our electrode structure (AS'-IPS), which not only increases substantially the aperture ratio over that of AS-IPS but also reduces the crosstalk using the same optimized thickness of the organic insulator layer.

  8. Supersonic combustion engine and method of combustion initiation and distribution

    SciTech Connect

    Stickler, D.B.; Ballantyne, A.; Kyuman Jeong.

    1993-06-29

    A supersonic combustion ramjet engine having a combustor with a combustion zone intended to channel gas flow at relatively high speed therethrough, the engine comprising: means for substantially continuously supplying fuel into the combustion zone; and means for substantially instantaneously igniting a volume of fuel in the combustion zone for providing a spatially controlled combustion distribution, the igniting means having means for providing a diffuse discharge of energy into the volume, the volume extending across a substantially complete cross-sectional area of the combustion zone, the means for discharging energy being capable of generating free radicals within the volume of reactive fuel in the combustion zone such that fuel in the volume can initiate a controlled relatively rapid combustion of fuel in the combustion zone whereby combustion distribution in relatively high speed gas flows through the combustion zone can be initiated and controlled without dependence upon a flame holder or relatively high local static temperature in the combustion zone.

  9. Tripropellant combustion process

    NASA Technical Reports Server (NTRS)

    Kmiec, T. D.; Carroll, R. G.

    1988-01-01

    The addition of small amounts of hydrogen to the combustion of LOX/hydrocarbon propellants in large rocket booster engines has the potential to enhance the system stability. Programs being conducted to evaluate the effects of hydrogen on the combustion of LOX/hydrocarbon propellants at supercritical pressures are described. Combustion instability has been a problem during the development of large hydrocarbon fueled rocket engines. At the higher combustion chamber pressures expected for the next generation of booster engines, the effect of unstable combustion could be even more destructive. The tripropellant engine cycle takes advantage of the superior cooling characteristics of hydrogen to cool the combustion chamber and a small amount of the hydrogen coolant can be used in the combustion process to enhance the system stability. Three aspects of work that will be accomplished to evaluate tripropellant combustion are described. The first is laboratory demonstration of the benefits through the evaluation of drop size, ignition delay and burning rate. The second is analytical modeling of the combustion process using the empirical relationship determined in the laboratory. The third is a subscale demonstration in which the system stability will be evaluated. The approach for each aspect is described and the analytical models that will be used are presented.

  10. Droplet Combustion Experiment

    NASA Technical Reports Server (NTRS)

    Nayagam, Vedha

    1998-01-01

    Liquid fuel combustion provides a major portion of the world's energy supply. In most practical combustion devices, liquid burns after being separated into a droplet spray. Essential to the design of efficient combustion systems is a knowledge of droplet combustion behavior. The microgravity environment aboard spacecraft provides an opportunity to investigate the complex interactions between the physical and chemical combustion processes involved in droplet combustion without the complications of natural buoyancy. Launched on STS-83 and STS-94 (April 4 and July 1, 1997), the Droplet Combustion Experiment (DCE) investigated the fundamentals of droplet combustion under a range of pressures (0.25 to 1 atm), oxygen mole fractions (<0.5), and droplet sizes (1.5 to 5 mm). Principal DCE flight hardware features were a chamber to supply selected test environments, the use of crew-inserted bottles, and a vent system to remove unwanted gaseous combustion products. The internal apparatus contained the droplet deployment and ignition mechanisms to burn single, freely deployed droplets in microgravity. Diagnostics systems included a 35-mm high-speed motion picture camera (see the following sequence of photos) with a backlight to photograph burning droplets and a camcorder to monitor experiment operations. Additional diagnostics included an ultraviolet-light-sensitive CCD (charge couple discharge) camera to obtain flame radiation from hydroxyl radicals (see the final figure) and a 35-mm SLR (single-lens-reflex) camera to obtain color still photographs of the flames.

  11. Combustion Byproducts Recycling Consortium

    SciTech Connect

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    Ashlines: To promote and support the commercially viable and environmentally sound recycling of coal combustion byproducts for productive uses through scientific research, development, and field testing.

  12. Emissions from premixed charge compression ignition (PCCI) combustion and affect on emission control devices

    SciTech Connect

    Parks, II, James E; Kass, Michael D; Huff, Shean P; Barone, Teresa L; Lewis Sr, Samuel Arthur; Prikhodko, Vitaly Y; Storey, John Morse

    2010-01-01

    A light-duty diesel engine has been operated in advanced combustion modes known generally as premixed charge compression ignition (PCCI). The emissions have been characterized for several load and speed combinations. Fewer NO{sub x} and particulate matter (PM) emissions are produced by PCCI, but higher CO and hydrocarbon (HC) emissions result. In addition, the nature of the PM differs from conventional combustion; the PM is smaller and has a much higher soluble organic fraction (SOF) content (68% vs. 30% for conventional combustion). Three catalyst technologies were studied to determine the affects of HECC on catalyst performance; the technologies were a lean NO{sub x} trap (LNT), diesel oxidation catalyst (DOC), and diesel particulate filter (DPF). The LNT benefited greatly from the reduced NO{sub x} emissions associated with PCCI. NO{sub x} capacity requirements are reduced as well as overall tailpipe NO{sub x} levels particularly at low load and temperature conditions where regeneration of the LNT is difficult. The DOC performance requirements for PCCI are more stringent due to the higher CO and HC emissions; however, the DOC was effective at controlling the higher CO and HC emissions at conditions above the light-off temperature. Below light-off, CO and HC emissions are problematic. The study of DPF technology focused on the fuel penalties associated with DPF regeneration or 'desoot' due to the different PM loading rates from PCCI vs. conventional combustion. Less frequent desoot events were required from the lower PM from PCCI and, when used in conjunction with an LNT, the lower PM from less frequent LNT regeneration. The lower desoot frequency leads a {approx}3% fuel penalty for a mixture of PCCI and conventional loads vs. {approx}4% for conventional only combustion.

  13. Solid Rocket Motor Combustion Instability Modeling in COMSOL Multiphysics

    NASA Technical Reports Server (NTRS)

    Fischbach, Sean R.

    2015-01-01

    Combustion instability modeling of Solid Rocket Motors (SRM) remains a topic of active research. Many rockets display violent fluctuations in pressure, velocity, and temperature originating from the complex interactions between the combustion process, acoustics, and steady-state gas dynamics. Recent advances in defining the energy transport of disturbances within steady flow-fields have been applied by combustion stability modelers to improve the analysis framework [1, 2, 3]. Employing this more accurate global energy balance requires a higher fidelity model of the SRM flow-field and acoustic mode shapes. The current industry standard analysis tool utilizes a one dimensional analysis of the time dependent fluid dynamics along with a quasi-three dimensional propellant grain regression model to determine the SRM ballistics. The code then couples with another application that calculates the eigenvalues of the one dimensional homogenous wave equation. The mean flow parameters and acoustic normal modes are coupled to evaluate the stability theory developed and popularized by Culick [4, 5]. The assumption of a linear, non-dissipative wave in a quiescent fluid remains valid while acoustic amplitudes are small and local gas velocities stay below Mach 0.2. The current study employs the COMSOL multiphysics finite element framework to model the steady flow-field parameters and acoustic normal modes of a generic SRM. The study requires one way coupling of the CFD High Mach Number Flow (HMNF) and mathematics module. The HMNF module evaluates the gas flow inside of a SRM using St. Robert's law to model the solid propellant burn rate, no slip boundary conditions, and the hybrid outflow condition. Results from the HMNF model are verified by comparing the pertinent ballistics parameters with the industry standard code outputs (i.e. pressure drop, thrust, ect.). These results are then used by the coefficient form of the mathematics module to determine the complex eigenvalues of the

  14. Analysis of Self-Excited Combustion Instabilities Using Decomposition Techniques

    DTIC Science & Technology

    2013-01-01

    the spatial mode kv would contain all normalized numbers and vice versa. Or, we can write Eq.(6) in this way, T k k k kA u v (7) In Eq.(7), ku is the...with traditional band -pass filtering based analysis for the study of self-excited combustion instabilities in a longitudinal mode rocket combustor. The...traditional band -pass filtering based analysis for the study of self-excited combustion instabilities in a longitudinal mode rocket combustor. The POD analysis

  15. AST Combustion Workshop: Diagnostics Working Group Report

    NASA Technical Reports Server (NTRS)

    Locke, Randy J.; Hicks, Yolanda R.; Hanson, Ronald K.

    1996-01-01

    A workshop was convened under NASA's Advanced Subsonics Technologies (AST) Program. Many of the principal combustion diagnosticians from industry, academia, and government laboratories were assembled in the Diagnostics/Testing Subsection of this workshop to discuss the requirements and obstacles to the successful implementation of advanced diagnostic techniques to the test environment of the proposed AST combustor. The participants, who represented the major relevant areas of advanced diagnostic methods currently applied to combustion and related fields, first established the anticipated AST combustor flowfield conditions. Critical flow parameters were then examined and prioritized as to their importance to combustor/fuel injector design and manufacture, environmental concerns, and computational interests. Diagnostic techniques were then evaluated in terms of current status, merits and obstacles for each flow parameter. All evaluations are presented in tabular form and recommendations are made on the best-suited diagnostic method to implement for each flow parameter in order of applicability and intrinsic value.

  16. Fifteenth combustion research conference

    SciTech Connect

    1993-06-01

    The BES research efforts cover chemical reaction theory, experimental dynamics and spectroscopy, thermodynamics of combustion intermediates, chemical kinetics, reaction mechanisms, combustion diagnostics, and fluid dynamics and chemically reacting flows. 98 papers and abstracts are included. Separate abstracts were prepared for the papers.

  17. Plasma Assisted Combustion

    DTIC Science & Technology

    2007-02-28

    2005) AIAA–2005–0405. [99] E.M. Van Veldhuizen (ed) Electrical Discharges for Environmental Purposes: Fun- damentals and Applications (New York: Nova...in russian), 18, 4, 1982, 48-51. [238] Combustion Chemestry , ed. W. Gardiner-Jr, Moscow, Mir, 1988. [239] G.P.Tewari, J.R.Wilson, Combust. Flame, 24

  18. Japan's microgravity combustion science program

    NASA Technical Reports Server (NTRS)

    Sato, Junichi

    1993-01-01

    Most of energy used by us is generated by combustion of fuels. On the other hand, combustion is responsible for contamination of our living earth. Combustion, also, gives us damage to our life as fire or explosive accidents. Therefore, clean and safe combustion is now eagerly required. Knowledge of the combustion process in combustors is needed to achieve proper designs that have stable operation, high efficiency, and low emission levels. However, current understanding on combustion is far from complete. Especially, there is few useful information on practical liquid and solid particle cloud combustion. Studies on combustion process under microgravity condition will provide many informations for basic questions related to combustors.

  19. Advanced Chemical Modeling for Turbulent Combustion Simulations

    DTIC Science & Technology

    2012-05-03

    combustor conditions. The resolved DNS dissipation rate is reasonably well described by the resolved component of the LES model (black solid line...our computed results with the non-linearly extrapolated burning velocities for m-xylene. 66 0 100 200 300 400 0 30 60 90 120 M ol e fr ac ...tio n [p pm ] t [ms] A1(CH3)2 x0.2 A1CH3 (a) 0 2 4 6 8 0 30 60 90 120 M ol e fr ac tio n [p pm ] t [ms] A1C2H5 (b) 0 20 40 60 80 100

  20. Versatile Affordable Advanced Fuels and Combustion Technologies

    DTIC Science & Technology

    2010-11-01

    Fuels, Vol. 22, No. 4, 2008 2415 165 elastomer is highly fluorinated and relatively inert, as evident by the very low percentage of volume swell. Previous...hydrogen bonding involves hydrogen bound to nearly any electrophilic structure not just a highly electrophilic atom such as oxygen and nitrogen

  1. Coal Combustion Science. Quarterly progress report, October--December 1994

    SciTech Connect

    Hardesty, D.R.; Baxter, L.L.; Davis, K.A.; Hurt, R.H.; Yang, N.Y.C.

    1996-02-01

    The objective of this work is to support the Office of Fossil Energy in executing research on coal combustion science. This project consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project. Specific tasks include: Task 1--Kinetics and mechanisms of pulverized coal char combustion; and Task 2--deposit growth and property development in coal-fired furnaces. The objective of task 1 is to characterize the combustion behavior of selected US coals under conditions relevant to industrial pulverized coal-fired furnaces. Work is being done in four areas: (a) kinetics of heterogeneous fuel particle populations; (b) char combustion kinetics at high carbon conversion; (c) the role of particle structure and the char formation process in combustion and; (d) unification of the Sandia char combustion data base. The objectives of Task 2 are to provide a self-consistent database of simultaneously measured, time-resolved, ash deposit properties in well-controlled and well-defined environments and to provide analytical expressions that relate deposit composition and structure to deposit properties of immediate relevance to PETC`s Combustion 2000 program. The task include the development and use of diagnostics to monitor, in situ and in real time, deposit properties, including information on both the structure and composition of the deposits.

  2. Combustion characteristics and influential factors of isooctane active-thermal atmosphere combustion assisted by two-stage reaction of n-heptane

    SciTech Connect

    Lu, Xingcai; Ji, Libin; Ma, Junjun; Zhou, Xiaoxin; Huang, Zhen

    2011-02-15

    This paper presents an experimental study on the isooctane active-thermal atmosphere combustion (ATAC) which is assisted by two-stage reaction of n-heptane. The active-thermal atmosphere is created by low- and high-temperature reactions of n-heptane which is injected at intake port, and isooctane is directly injected into combustion chamber near the top dead center. The effects of isooctane injection timing, active-thermal atmosphere intensity, overall equivalence ratio, and premixed ratio on combustion characteristics and emissions are investigated. The experimental results reveal that, the isooctane ignition and combustion can be classified to thermal atmosphere combustion, active atmosphere combustion, and active-thermal atmosphere combustion respectively according to the extent of n-heptane oxidation as well as effects of isooctane quenching and charge cooling. n-Heptane equivalence ratio, isooctane equivalence ratio and isooctane delivery advance angle are major control parameters. In one combustion cycle, the isooctane ignited and burned after those of n-heptane, and then this combustion phenomenon can also be named as dual-fuel sequential combustion (DFSC). The ignition timing of the overall combustion event is mainly determined by n-heptane equivalence ratio and can be controlled in flexibility by simultaneously adjusting isooctane equivalence ratio. The isooctane ignition regime, overall thermal efficiency, and NO{sub x} emissions show strong sensitivity to the fuel delivery advance angle between 20 CA BTDC and 25 CA BTDC. (author)

  3. Combustion Stability Analyses of Coaxial Element Injectors with Liquid Oxygen/Liquid Methane Propellants

    NASA Technical Reports Server (NTRS)

    Hulka, J. R.

    2010-01-01

    Liquid rocket engines using oxygen and methane propellants are being considered by the National Aeronautics and Space Administration (NASA) for in-space vehicles. This propellant combination has not been previously used in a flight-qualified engine system, so limited test data and analysis results are available at this stage of early development. NASA has funded several hardware-oriented activities with oxygen and methane propellants over the past several years with the Propulsion and Cryogenic Advanced Development (PCAD) project, under the Exploration Technology Development Program. As part of this effort, the NASA Marshall Space Flight Center has conducted combustion stability analyses of several of the configurations. This paper presents test data and analyses of combustion stability from the recent PCAD-funded test programs at the NASA MSFC. These test programs used swirl coaxial element injectors with liquid oxygen and liquid methane propellants. Oxygen was injected conventionally in the center of the coaxial element, and swirl was provided by tangential entry slots. Injectors with 28-element and 40-element patterns were tested with several configurations of combustion chambers, including ablative and calorimeter spool sections, and several configurations of fuel injection design. Low frequency combustion instability (chug) occurred with both injectors, and high-frequency combustion instability occurred at the first tangential (1T) transverse mode with the 40-element injector. In most tests, a transition between high-amplitude chug with gaseous methane flow and low-amplitude chug with liquid methane flow was readily observed. Chug analyses of both conditions were conducted using techniques from Wenzel and Szuch and from the Rocket Combustor Interactive Design and Analysis (ROCCID) code. The 1T mode instability occurred in several tests and was apparent by high-frequency pressure measurements as well as dramatic increases in calorimeter-measured heat flux

  4. Commercial investments in Combustion research aboard ISS

    NASA Astrophysics Data System (ADS)

    Schowengerdt, F. D.

    2000-01-01

    The Center for Commercial Applications of Combustion in Space (CCACS) at the Colorado School of Mines is working with a number of companies planning commercial combustion research to be done aboard the International Space Station (ISS). This research will be conducted in two major ISS facilities, SpaceDRUMS™ and the Fluids and Combustion Facility. SpaceDRUMS™, under development by Guigne Technologies, Ltd., of St. John's Newfoundland, is a containerless processing facility employing active acoustic sample positioning. It is capable of processing the large samples needed in commercial research and development with virtually complete vibration isolation from the space station. The Fluids and Combustion Facility (FCF), being developed by NASA-Glenn Research Center in Cleveland, is a general-purpose combustion furnace designed to accommodate a wide range of scientific experiments. SpaceDRUMS™ will be the first commercial hardware to be launched to ISS. Launch is currently scheduled for UF-1 in 2001. The CCACS research to be done in SpaceDRUMS™ includes combustion synthesis of glass-ceramics and porous materials. The FCF is currently scheduled to be launched to ISS aboard UF-3 in 2002. The CCACS research to be done in the FCF includes water mist fire suppression, catalytic combustion and flame synthesis of ceramic powders. The companies currently planning to be involved in the research include Guigne International, Ltd., Technology International, Inc., Coors Ceramics Company, TDA Research, Advanced Refractory Technologies, Inc., ADA Technologies, Inc., ITN Energy Systems, Inc., Innovative Scientific Solutions, Inc., Princeton Instruments, Inc., Environmental Engineering Concepts, Inc., and Solar Turbines, Inc. Together, these companies are currently investing almost $2 million in cash and in-kind annually toward the seven commercial projects within CCACS. Total private investment in CCACS research to date is over $7 million. .

  5. Hydrogen-Assisted IC Engine Combustion as a Route to Hydrogen Implementation

    SciTech Connect

    Andre Boehman; Daniel Haworth

    2008-09-30

    The 'Freedom Car' Initiative announced by the Bush Administration has placed a significant emphasis on development of a hydrogen economy in the United States. While the hydrogen-fueled fuel-cell vehicle that is the focus of the 'Freedom Car' program would rely on electrochemical energy conversion, and despite the large amount of resources being devoted to its objectives, near-term implementation of hydrogen in the transportation sector is not likely to arise from fuel cell cars. Instead, fuel blending and ''hydrogen-assisted'' combustion are more realizable pathways for wide-scale hydrogen utilization within the next ten years. Thus, a large potential avenue for utilization of hydrogen in transportation applications is through blending with natural gas, since there is an existing market for natural-gas vehicles of various classes, and since hydrogen can provide a means of achieving even stricter emissions standards. Another potential avenue is through use of hydrogen to 'assist' diesel combustion to permit alternate combustion strategies that can achieve lower emissions and higher efficiency. This project focused on developing the underlying fundamental information to support technologies that will facilitate the introduction of coal-derived hydrogen into the market. Two paths were envisioned for hydrogen utilization in transportation applications. One is for hydrogen to be mixed with other fuels, specifically natural gas, to enhance performance in existing natural gas-fueled vehicles (e.g., transit buses) and provide a practical and marketable avenue to begin using hydrogen in the field. A second is to use hydrogen to enable alternative combustion modes in existing diesel engines, such as homogeneous charge compression ignition, to permit enhanced efficiency and reduced emissions. Thus, this project on hydrogen-assisted combustion encompassed two major objectives: (1) Optimization of hydrogen-natural gas mixture composition and utilization through laboratory

  6. Internal combustion engine for natural gas compressor operation

    SciTech Connect

    Hagen, Christopher; Babbitt, Guy

    2016-12-27

    This application concerns systems and methods for compressing natural gas with an internal combustion engine. In a representative embodiment, a method is featured which includes placing a first cylinder of an internal combustion engine in a compressor mode, and compressing a gas within the first cylinder, using the cylinder as a reciprocating compressor. In some embodiments a compression check valve system is used to regulate pressure and flow within cylinders of the engine during a compression process.

  7. Active control of combustion instabilities

    NASA Astrophysics Data System (ADS)

    Al-Masoud, Nidal A.

    A theoretical analysis of active control of combustion thermo-acoustic instabilities is developed in this dissertation. The theoretical combustion model is based on the dynamics of a two-phase flow in a liquid-fueled propulsion system. The formulation is based on a generalized wave equation with pressure as the dependent variable, and accommodates all influences of combustion, mean flow, unsteady motions and control inputs. The governing partial differential equations are converted to an equivalent set of ordinary differential equations using Galerkin's method by expressing the unsteady pressure and velocity fields as functions of normal mode shapes of the chamber. This procedure yields a representation of the unsteady flow field as a system of coupled nonlinear oscillators that is used as a basis for controllers design. Major research attention is focused on the control of longitudinal oscillations with both linear and nonlinear processes being considered. Starting with a linear model using point actuators, the optimal locations of actuators and sensors are developed. The approach relies on the quantitative measures of the degree of controllability and component cost. These criterion are arrived at by considering the energies of the system's inputs and outputs. The optimality criteria for sensor and actuator locations provide a balance between the importance of the lower order (controlled) and the higher (residual) order modes. To address the issue of uncertainties in system's parameter, the minimax principles based controller is used. The minimax corresponds to finding the best controller for the worst parameter deviation. In other words, choosing controller parameters to minimize, and parameter deviation to maximize some quadratic performance metric. Using the minimax-based controller, a remarkable improvement in the control system's ability to handle parameter uncertainties is achieved when compared to the robustness of the regular control schemes such as LQR

  8. Studies on the mixing of liquid jets and pre-atomized sprays in confined swirling air flows for lean direct injection combustion

    NASA Astrophysics Data System (ADS)

    Huh, Jun-Young

    A lean direct injection (LDI) combustion concept was introduced recently to obtain both low NOsbx emissions and high performance for advanced aircraft gas turbine engines. It was reported that pollutant emissions, especially NOsbx, in a lean combustion mode depend significantly on the degree of mixing (mixedness) of supplied air and liquid fuel droplets. From a viewpoint of environmental protection, therefore, uniform mixing of fuel and air in a very short period of time, i.e., well-stirred mixing, is crucially important in the LDI combustion mode. In the present study, as the first stage toward understanding the combustion phenomena in a lean direct injection (LDI) mode, the hydrodynamic behavior of liquid jets and pre-atomized sprays in confined swirling air flows is investigated. Laser-based flow visualization and image analysis techniques are applied to analyze the instantaneous motion of the mixing process of the jets and pre-atomized sprays. Statistical analysis system (SAS) software is utilized to analyze the experimental data, and correlate experimental parameters. Statistical parameters, such as centrality, degree of spread, and total area ratio of particles, are defined in this study, and used to quantify the mixedness (degree of mixing) of liquid particles in confined geometry. Two empirical equations are obtained to predict jet intact lengths and spray angles, respectively, in confined swirling air flows. It is found that initial jet characteristics, such as intact length and spray angle, determine the mixing of the liquid particles resulting from the jet. It is verified that image analysis is feasible in quantitative determination of the mixedness of liquid particles. Even though substantial improvements in liquid fuel injector systems are required before they can be considered adequate for LDI combustion at high pressure and high temperature, the results and ideas obtained from the present study will help engineers find better mixing methods for LDI

  9. Design factors for stable lean premix combustion

    SciTech Connect

    Richards, G.A.; Yip, M.J.; Gemmen, R.S.

    1995-10-01

    The Advanced Turbine Systems (ATS) program includes the development of low-emission combustors. Low emissions have already been achieved by premixing fuel and air to avoid the hot gas pockets produced by nozzles without premixing. While the advantages of premixed combustion have been widely recognized, turbine developers using premixed nozzles have experienced repeated problems with combustion oscillations. Left uncontrolled, these oscillations can lead to pressure fluctuations capable of damaging engine hardware. Elimination of such oscillations is often difficult and time consuming - particularly when oscillations are discovered in the last stages of engine development. To address this issue, METC is studying oscillating combustion from lean premixing fuel nozzles. These tests are providing generic information on the mechanisms that contribute to oscillating behavior in gas turbines. METC is also investigating the use of so-called {open_quotes}active{close_quotes} control of combustion oscillations. This technique periodically injects fuel pulses into the combustor to disrupt the oscillating behavior. Recent results on active combustion control are presented in Gemmen et al. (1995) and Richards et al. (1995). This paper describes the status of METC efforts to avoid oscillations through simple design changes.

  10. Axisymmetric single shear element combustion instability experiment

    NASA Technical Reports Server (NTRS)

    Breisacher, Kevin J.

    1993-01-01

    The combustion stability characteristics of a combustor consisting of a single shear element and a cylindrical chamber utilizing LOX and gaseous hydrogen as propellants are presented. The combustor geometry and the resulting longitudinal mode instability are axisymmetric. Hydrogen injection temperature and pyrotechnic pulsing were used to determine stability boundaries. Mixture ratio, fuel annulus gap, and LOX post configuration were varied. Performance and stability data were obtained for chamber pressures of 300 and 1000 psia.

  11. Axisymmetric single shear element combustion instability experiment

    NASA Technical Reports Server (NTRS)

    Breisacher, Kevin J.

    1993-01-01

    The combustion stability characteristics of a combustor consisting of a single shear element and a cylindrical chamber utilizing LOX and gaseous hydrogen as propellants are presented. The combustor geometry and the resulting longitudinal mode instability are axisymmetric. Hydrogen injection temperature and pyrotechnic pulsing were used to determine stability boundaries. Mixture ratio, fuel annulus gap, and LOX post configuration were varied. Performance and stability data are presented for chamber pressures of 300 and 1000 psia.

  12. Techniques for Liquid Rocket Combustion Spontaneous Stability and Rough Combustion Assessments

    NASA Technical Reports Server (NTRS)

    Kenny, R. J.; Giacomoni, C.; Casiano, M. J.; Fischbach, S. R.

    2016-01-01

    This work presents techniques for liquid rocket engine combustion stability assessments with respect to spontaneous stability and rough combustion. Techniques covering empirical parameter extraction, which were established in prior works, are applied for three additional programs: the F-1 Gas Generator (F1GG) component test program, the RS-84 preburner component test program, and the Marshall Integrated Test Rig (MITR) program. Stability assessment parameters from these programs are compared against prior established spontaneous stability metrics and updates are identified. Also, a procedure for comparing measured with predicted mode shapes is presented, based on an extension of the Modal Assurance Criterion (MAC).

  13. Alternate Fuels Combustion Research

    DTIC Science & Technology

    1984-07-01

    AFWAL-TR-84-2042 ESL-TR-84-29 ALTERNATE FUELS COMBUSTION RESEARCH 0) PRATT & WHITNEY CANADA MISSISSAUGA, ONTARIO CANADA In JULY 1984 Final Report for...in small engincs. -291 REFERENCES 1. Gratton, M., Sampath, P., " Alternate Fuels Combustion Research Phase If", Pratt & Whitney Canada , AFWAL-TR-83-2057...for Period May 80 Sep e ALTERNATE FUELS COMBUSTION RESEARCHMa80-Sp3 4. PERFORMING ORIJ. REPORT NUMBER 7. AUTNOR(s) 4. 60ONTRA-CT-WI GANUMNER(s) *M

  14. Dry low combustion system with means for eliminating combustion noise

    DOEpatents

    Verdouw, Albert J.; Smith, Duane; McCormick, Keith; Razdan, Mohan K.

    2004-02-17

    A combustion system including a plurality of axially staged tubular premixers to control emissions and minimize combustion noise. The combustion system includes a radial inflow premixer that delivers the combustion mixture across a contoured dome into the combustion chamber. The axially staged premixers having a twist mixing apparatus to rotate the fluid flow and cause improved mixing without causing flow recirculation that could lead to pre-ignition or flashback.

  15. Calculation of Supersonic Combustion Using Implicit Schemes

    NASA Technical Reports Server (NTRS)

    Yoon, Seokkwan; Kwak, Dochan (Technical Monitor)

    2003-01-01

    One of the technology goals of NASA for advanced space transportation is to develop highly efficient propulsion systems to reduce the cost of payload for space missions. Developments of rockets for the second generation Reusable Launch Vehicle (RLV) in the past several years have been focused on low-cost versions of conventional engines. However, recent changes in the Integrated Space Transportation Program to build a crew transportation vehicle to extend the life of the Space Shuttle fleet might suggest that air-breathing rockets could reemerge as a possible propulsion system for the third generation RLV to replace the Space Shuttle after 2015. The weight of the oxygen tank exceeds thirty percent of the total weight of the Space Shuttle at launch while the payload is only one percent of the total weight. The air-breathing rocket propulsion systems, which consume oxygen in the air, offer clear advantages by making vehicles lighter and more efficient. Experience in the National Aerospace Plane Program in the late 1980s indicates that scramjet engines can achieve high specific impulse for low hypersonic vehicle speeds. Whether taking a form of Rocket Based Combined Cycle (RBCC) or Turbine Based Combined Cycle (TBCC), the scramjet is an essential mode of operation for air-breathing rockets. It is well known that fuel-air mixing and rapid combustion are of crucial importance for the success of scramjet engines since the spreading rate of the supersonic mixing layer decreases as the Mach number increases. A factored form of the Gauss-Seidel relaxation method has been widely used in hypersonic flow research since its first application to non-equilibrium flows. However, difficulties in stability and convergence have been encountered when there is strong interaction between fluid motion and chemical reaction, such as multiple fuel injection problems. The present paper reports the results from investigation of the effect of modifications to the original algorithm on the

  16. Sandia Combustion Research: Technical review

    SciTech Connect

    1995-07-01

    This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

  17. Abstracts: 1982 AFOSR Contractors Meeting on Air Breathing Combustion Dynamics Research, held 1-4 November 1982, Clearwater Beach, Florida.

    DTIC Science & Technology

    1982-11-01

    Development of Gas Turbine Combustors H. Mongia Garrett Institute Engine Company 9:20 Fundamental Combustion Studies with Conventional and Alternate Fuel... Future investigations in this area include measurements at higher Reynolds numbers and increasing amounts of heat release. Additionally, the HF combustion ...will require the effective utilization of alternative fuels and advanced combustor concepts . Therefore, further understanding of spray combustion

  18. Development of High Efficiency and Low Emission Low Temperature Combustion Diesel Engine with Direct EGR Injection

    NASA Astrophysics Data System (ADS)

    Ho, R. J.; Kumaran, P.; Yusoff, M. Z.

    2016-03-01

    Focus on energy and environmental sustainability policy has put automotive research & development directed to developing high efficiency and low pollutant power train. Diffused flame controlled diesel combustion has reach its limitation and has driven R&D to explore other modes of combustions. Known effective mode of combustion to reduce emission are Low temperature combustion (LTC) and homogeneous charge combustion ignition by suppressing Nitrogen Oxide(NOx) and Particulate Matter (PM) formation. The key control to meet this requirement are chemical composition and distribution of fuel and gas during a combustion process. Most research to accomplish this goal is done by manipulating injected mass flow rate and varying indirect EGR through intake manifold. This research paper shows viable alternative direct combustion control via co-axial direct EGR injection with fuel injection process. A simulation study with OpenFOAM is conducted by varying EGR injection velocity and direct EGR injector diameter performed with under two conditions with non-combustion and combustion. n-heptane (C7H16) is used as surrogate fuel together with 57 species 290 semi-detailed chemical kinetic model developed by Chalmers University is used for combustion simulation. Simulation result indicates viability of co-axial EGR injection as a method for low temperature combustion control.

  19. Analytical and numerical studies on a single-droplet evaporation and combustion under forced convection

    NASA Astrophysics Data System (ADS)

    Zhou, L. X.; Li, K.

    2015-08-01

    Existing droplet evaporation/combustion models in computational fluid dynamics (CFD) simulation of spray combustion are based on simplified 1-D models. Both these models and recently developed 3-D models of single-droplet combustion do not give the conditions for the different existing droplet combustion modes. In this paper, droplet evaporation and combustion are studied both analytically and numerically. In the analytical solution, a 2-D axisymmetric flow surrounding an evaporating and combusting droplet was considered. The governing equations were solved using an integral method, similar to the Karman-Pohlhausen method for solving boundary-layer flows with pressure gradient. The results give a local evaporation rate and flame radius in agreement with experimental results. In numerical simulation, 3-D combusting gas flows surrounding an ethanol droplet were studied. The prediction results show three modes of droplet combustion under different relative velocities, explaining the change in the evaporation constant with an increase in relative velocity observed in experiments. This implies that different droplet combustion models should be developed in simulating spray combustion. The predicted local evaporation rate and flame radius by numerical simulation are in agreement with the analytical solution in the range of azimuthal angles . The numerical results indicate that the drag force of an evaporating and combusting droplet is much smaller than that of a cold solid particle, and thus the currently used drag models should be modified.

  20. Characterization and modes of occurrence of elements in feed coal and coal combustion products from a power plant utilizing low-sulfur coal from the Powder River Basin, Wyoming

    USGS Publications Warehouse

    Brownfield, Michael E.; Cathcart, James D.; Affolter, Ronald H.; Brownfield, Isabelle K.; Rice, Cynthia A.; O'Connor, Joseph T.; Zielinski, Robert A.; Bullock, John H.; Hower, James C.; Meeker, Gregory P.

    2005-01-01

    The U.S. Geological Survey and the University of Kentucky Center for Applied Energy Research are collaborating with an Indiana utility company to determine the physical and chemical properties of feed coal and coal combustion products from a coal-fired power plant. The Indiana power plant utilizes a low-sulfur (0.23 to 0.47 weight percent S) and lowash (4.9 to 6.3 weight percent ash) subbituminous coal from the Wyodak-Anderson coal zone in the Tongue River Member of the Paleocene Fort Union Formation, Powder River Basin, Wyoming. Based on scanning electron microscope and X-ray diffraction analyses of feed coal samples, two mineral suites were identified: (1) a primary or detrital suite consisting of quartz (including beta-form grains), biotite, feldspar, and minor zircon; and (2) a secondary authigenic mineral suite containing alumino-phosphates (crandallite and gorceixite), kaolinite, carbonates (calcite and dolomite), quartz, anatase, barite, and pyrite. The primary mineral suite is interpreted, in part, to be of volcanic origin, whereas the authigenic mineral suite is interpreted, in part, to be the result of the alteration of the volcanic minerals. The mineral suites have contributed to the higher amounts of barium, calcium, magnesium, phosphorus, sodium, strontium, and titanium in the Powder River Basin feed coals in comparison to eastern coals. X-ray diffraction analysis indicates that (1) fly ash is mostly aluminate glass, perovskite, lime, gehlenite, quartz, and phosphates with minor amounts of periclase, anhydrite, hematite, and spinel group minerals; and (2) bottom ash is predominantly quartz, plagioclase (albite and anorthite), pyroxene (augite and fassaite), rhodonite, and akermanite, and spinel group minerals. Microprobe and scanning electron microscope analyses of fly ash samples revealed quartz, zircon, and monazite, euhedral laths of corundum with merrillite, hematite, dendritic spinels/ferrites, wollastonite, and periclase. The abundant calcium and

  1. Measure Guideline: Combustion Safety for Natural Draft Appliances Through Appliance Zone Isolation

    SciTech Connect

    Fitzgerald, J.; Bohac, D.

    2014-04-01

    This measure guideline covers how to assess and carry out the isolation of natural draft combustion appliances from the conditioned space of low-rise residential buildings. It deals with combustion appliances located either within the living space in enclosed closets or side rooms or outside the living space in an adjacent area like an attic or garage. This subset of houses does not require comprehensive combustion safety tests and simplified prescriptive procedures can be used to address safety concerns. This allows residential energy retrofit contractors inexperienced in advanced combustion safety testing to effectively address combustion safety issues and allow energy retrofits including tightening and changes to distribution and ventilation systems to proceed.

  2. DUAL-MODE PROPULSION SYSTEM ENABLING CUBESAT EXPLORATION OF THE SOLAR SYSTEM NASA Innovative Advanced Concepts (NIAC) Phase I Final Report

    SciTech Connect

    Nathan Jerred; Troy Howe; Adarsh Rajguru; Dr. Steven Howe

    2014-06-01

    -based systems. The second scenario allows for the production of electrical power, which is then available for electric-based propulsion. Additionally, once at location the production of electrical power can be dedicated to the payload’s communication system for data transfer. Ultimately, the proposed dual-mode propulsion platform capitalizes on the benefits of two types of propulsion methods – the thrust of thermal propulsion ideal for quick orbital maneuvers and the specific impulse of electric propulsion ideal for efficient inter-planetary travel. Previous versions of this RTR-based concept have been studied for various applications [NETS 1-3]. The current version of this concept is being matured through a NASA Innovative Advanced Concepts (NIAC) Phase I grant, awarded for FY 2014. In this study the RTR concept is being developed to deliver a 6U CubeSat payload to the orbit of the Saturnian moon - Enceladus. Additionally, this study will develop an entire mission architecture for Enceladus targeting a total allowable launch mass of 1,000 kg.

  3. Modeling aerosol emissions from the combustion of composite materials

    NASA Technical Reports Server (NTRS)

    Roop, J. A.; Caldwell, D. J.; Kuhlmann, K. J.

    1994-01-01

    The use of advanced composite materials (ACM) in the B-2 bomber, composite armored vehicle, and F-22 advanced tactical fighter has rekindled interest concerning the health risk of burned or burning ACM. The objective of this work was to determine smoke production from burning ACM and its toxicity. A commercial version of the UPITT II combustion toxicity method developed at the University of Pittsburgh, and subsequently refined through a US Army-funded basic research project, was used to established controlled combustion conditions which were selected to evaluate real-world exposure scenarios. Production and yield of toxic species varied with the combustion conditions. Previous work with this method showed that the combustion conditions directly influenced the toxicity of the decomposition products from a variety of materials.

  4. Combustion Technology Outreach

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Lewis' High Speed Research (HSR) Propulsion Project Office initiated a targeted outreach effort to market combustion-related technologies developed at Lewis for the next generation of supersonic civil transport vehicles. These combustion-related innovations range from emissions measurement and reduction technologies, to diagnostics, spray technologies, NOx and SOx reduction of burners, noise reduction, sensors, and fuel-injection technologies. The Ohio Aerospace Institute and the Great Lakes Industrial Technology Center joined forces to assist Lewis' HSR Office in this outreach activity. From a database of thousands of nonaerospace firms considered likely to be interested in Lewis' combustion and emission-related technologies, the outreach team selected 41 companies to contact. The selected companies represent oil-gas refineries, vehicle/parts suppliers, and manufacturers of residential furnaces, power turbines, nonautomobile engines, and diesel internal combustion engines.

  5. Fluidized coal combustion

    NASA Technical Reports Server (NTRS)

    Moynihan, P. I.; Young, D. L.

    1979-01-01

    Fluidized-bed coal combustion process, in which pulverized coal and limestone are burned in presence of forced air, may lead to efficient, reliable boilers with low sulfur dioxide and nitrogen dioxide emissions.

  6. Studies in premixed combustion

    SciTech Connect

    Sivashinsky, G.I.

    1992-01-01

    This report discusses the following topics on premixed combustion: theory of turbulent flame propagation; pattern formation in premixed flames and related problems; and pattern formation in extended systems. (LSP)

  7. TENORM: Coal Combustion Residuals

    EPA Pesticide Factsheets

    Burning coal in boilers to create steam for power generation and industrial applications produces a number of combustion residuals. Naturally radioactive materials that were in the coal mostly end up in fly ash, bottom ash and boiler slag.

  8. Dynamic effects of combustion

    NASA Technical Reports Server (NTRS)

    Oppenheim, A. K.

    1982-01-01

    The dynamic effects of combustion are due to the evolution of exothermic energy and its deposition in the compressible medium where the process takes place. The paper examines the dynamics of combustion phenomena, including ignition, turbulent flame propagation (inflammation), explosion, and detonation, with emphasis on their exothermic characteristics. Ignition and explosion are treated as problems of nonlinear mechanics, and their dynamic behavior is described in terms of phase space models and cinematographic laser shear interferograms. The results of a numerical random vortex model of turbulent flame propagation are confirmed in a combustion tunnel experiment, where it was observed that a fresh mixture of burnt and unburnt gases can sustain combustion with a relatively small expenditure of overall mass flow, due to the increasing specific volume of burnt gases inside the flame front. An isentropic pressure wave is found to precede the accelerating flame in the process of detonation, and components of this presssure wave are shown to propagate at local sonic velocities.

  9. Critical research and advanced technology (CRT) support project

    NASA Technical Reports Server (NTRS)

    Furman, E. R.; Anderson, D. N.; Hodge, P. E.; Lowell, C. E.; Nainiger, J. J.; Schultz, D. F.

    1983-01-01

    A critical technology base for utility and industrial gas turbines by planning the use of coal-derived fuels was studied. Development tasks were included in the following areas: (1) Combustion - investigate the combustion of coal-derived fuels and methods to minimize the conversion of fuel-bound nitrogen to NOx; (2) materials - understand and minimize hot corrosion; (3) system studies - integrate and focus the technological efforts. A literature survey of coal-derived fuels was completed and a NOx emissions model was developed. Flametube tests of a two-stage (rich-lean) combustor defined optimum equivalence ratios for minimizing NOx emissions. Sector combustor tests demonstrated variable air control to optimize equivalence ratios over a wide load range and steam cooling of the primary zone liner. The catalytic combustion of coal-derived fuels was demonstrated. The combustion of coal-derived gases is very promising. A hot-corrosion life prediction model was formulated and verified with laboratory testing of doped fuels. Fuel additives to control sulfur corrosion were studied. The intermittent application of barium proved effective. Advanced thermal barrier coatings were developed and tested. Coating failure modes were identified and new material formulations and fabrication parameters were specified. System studies in support of the thermal barrier coating development were accomplished.

  10. Discrete model of gas-free spin combustion of a powder mixture.

    PubMed

    Klimenok, Kirill L; Rashkovskiy, Sergey A

    2015-01-01

    We propose a discrete model of gas-free combustion of a cylindrical sample which reproduces in detail a spin combustion mode. It is shown that a spin combustion, in its classical sense as a continuous spiral motion of heat release zones on the surface of the sample, does not exist. Such a concept has arisen due to the misinterpretation of the experimental data. This study shows that in fact a spinlike combustion is realized, at which two energy release zones appear on the lateral surface of the sample and propagate circumferentially in the opposite directions. After some time two new heat release zones are formed on the next layer of the cylinder surface and make the same counter-circular motion. This process continues periodically and from a certain angle it looks like a spiral movement of the luminous zone along the lateral surface of the sample. The model shows that on approaching the combustion limit the process becomes more complicated and the spinlike combustion mode shifts to a more complex mode with multiple zones of heat release moving in different directions along the lateral surface. It is shown that the spin combustion mode appears due to asymmetry of initial conditions and always transforms into a layer-by-layer combustion mode with time.

  11. Scramjet Combustion Processes

    DTIC Science & Technology

    2010-09-01

    plan for these flights is as follows: Scramjet Combustion Processes RTO-EN-AVT-185 11 - 21 HyShot 5 – A Free-Flying Hypersonic Glider HyShot...5 will be a hypersonic glider designed to fly at Mach 8. It will separate from its rocket booster in space and perform controlled manoeuvres as it...RTO-EN-AVT-185 11 - 1 Scramjet Combustion Processes Michael Smart and Ray Stalker Centre for Hypersonics The University of Queensland

  12. Sandia Combustion Research Program

    SciTech Connect

    Johnston, S.C.; Palmer, R.E.; Montana, C.A.

    1988-01-01

    During the late 1970s, in response to a national energy crisis, Sandia proposed to the US Department of Energy (DOE) a new, ambitious program in combustion research. Shortly thereafter, the Combustion Research Facility (CRF) was established at Sandia's Livermore location. Designated a ''user facility,'' the charter of the CRF was to develop and maintain special-purpose resources to support a nationwide initiative-involving US inventories, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions several research projects which have been simulated by working groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship program, supported through the Office of Energy Research, has been instrumental in the success of some of these joint efforts. The remainder of this report presents results of calendar year 1988, separated thematically into eleven categories. Referred journal articles appearing in print during 1988 and selected other publications are included at the end of Section 11. Our traditional'' research activities--combustion chemistry, reacting flows, diagnostics, engine and coal combustion--have been supplemented by a new effort aimed at understanding combustion-related issues in the management of toxic and hazardous materials.

  13. Coal combustion system

    DOEpatents

    Wilkes, Colin; Mongia, Hukam C.; Tramm, Peter C.

    1988-01-01

    In a coal combustion system suitable for a gas turbine engine, pulverized coal is transported to a rich zone combustor and burned at an equivalence ratio exceeding 1 at a temperature above the slagging temperature of the coal so that combustible hot gas and molten slag issue from the rich zone combustor. A coolant screen of water stretches across a throat of a quench stage and cools the combustible gas and molten slag to below the slagging temperature of the coal so that the slag freezes and shatters into small pellets. The pelletized slag is separated from the combustible gas in a first inertia separator. Residual ash is separated from the combustible gas in a second inertia separator. The combustible gas is mixed with secondary air in a lean zone combustor and burned at an equivalence ratio of less than 1 to produce hot gas motive at temperature above the coal slagging temperature. The motive fluid is cooled in a dilution stage to an acceptable turbine inlet temperature before being transported to the turbine.

  14. Broad Specification Fuels Combustion Technology Program. Phase 2

    DTIC Science & Technology

    1990-10-01

    128 7.2.7 Combustion Stability 131 7.3 Modifications to the Variable Geometry Combustor Concept 131 7.3.1 Initial Variable Geometry Combustor...implied that combustion was being restricted to areas close to the liners. Based on these observations it was evident that the fundamental concept of...these concepts represent advanced technology approaches that are more likely to find application in future engines rather than in retrofit into older

  15. Glass Furnace Combustion and Melting Research Facility.

    SciTech Connect

    Connors, John J.; McConnell, John F.; Henry, Vincent I.; MacDonald, Blake A.; Gallagher, Robert J.; Field, William B.; Walsh, Peter M.; Simmons, Michael C.; Adams, Michael E.; Leadbetter, James M.; Tomasewski, Jack W.; Operacz, Walter J.; Houf, William G.; Davis, James W.; Marvin, Bart G.; Gunner, Bruce E.; Farrell, Rick G.; Bivins, David P.; Curtis, Warren; Harris, James E.

    2004-08-01

    solution of proprietary glass production problems. As a consequence of the substantial increase in scale and scope of the initial furnace concept in response to industry recommendations, constraints on funding of industrial programs by DOE, and reorientation of the Department's priorities, the OIT Glass Program is unable to provide the support for construction of such a facility. However, it is the present investigators' hope that a group of industry partners will emerge to carry the project forward, taking advantage of the detailed furnace design presented in this report. The engineering, including complete construction drawings, bill of materials, and equipment specifications, is complete. The project is ready to begin construction as soon as the quotations are updated. The design of the research melter closely follows the most advanced industrial practice, firing by natural gas with oxygen. The melting area is 13 ft x 6 ft, with a glass depth of 3 ft and an average height in the combustion space of 3 ft. The maximum pull rate is 25 tons/day, ranging from 100% batch to 100% cullet, continuously fed, with variable batch composition, particle size distribution, and raft configuration. The tank is equipped with bubblers to control glass circulation. The furnace can be fired in three modes: (1) using a single large burner mounted on the front wall, (2) by six burners in a staggered/opposed arrangement, three in each breast wall, and (3) by down-fired burners mounted in the crown in any combination with the front wall or breast-wall-mounted burners. Horizontal slots are provided between the tank blocks and tuck stones and between the breast wall and skewback blocks, running the entire length of the furnace on both sides, to permit access to the combustion space and the surface of the glass for optical measurements and sampling probes. Vertical slots in the breast walls provide additional access for measurements and sampling. The furnace and tank are to be fully instrumented

  16. Combustion Characteristics of a Hypermixer Scramjet Engine

    NASA Astrophysics Data System (ADS)

    Sunami, Tetsuji; Itoh, Katsuhiro; Komuro, Tomoyuki; Sato, Kazuo

    A scramjet engine with a wall-mounted hypermixer injector, which generates streamwise vortices for enhancing supersonic mixing and combustion, is examined at a Mach 8 simulated flight condition in the High Enthalpy Shock Tunnel (HIEST). The engine and the fuel injector are full scale models of the HyShot-IV flight experiment planned for 2005 by JAXA and University of Queensland (UQ). Main purpose of the present study is to clarify the combustion and operation characteristics of the hypermixer scramjet owing to the ability of the streamwise vortices for mixing enhancement and boundary layer control. For comparison, two injectors with normal and parallel injection without streamwise vortex generation are also examined. The results show the superior performance of the hypermixer injector in scramjet mode obtaining higher pressure rise in a shorter distance compared to the other two injectors. In the case of the hypermixer injector, a 1D analysis of an inviscid nozzle flow shows the increment in the specific impulse due to combustion to be 2,649 and 2,224 sec for the equivalence ratio, Φ=0.3 and 0.6, respectively. At Φ=1.0 and 1.5, sudden rapid combustion of the premixed fuel at the end of the combustor generates a strong pressure wave, which propagates upstream up to the injector location and decades there. As a result, a new quasi-steady combusting flow is established throughout the combustor downstream of the injector. The pressure wave is identified as a kind of detonation wave, which is suggested to propagate upstream mainly through the streamwise vortices. As a driving force of the upstream propagation of the detonation wave, mixing and combustion enhanced through the interaction between the detonation wave and the streamwise vortices are considered.

  17. Chemical Kinetic Modeling of Biofuel Combustion

    NASA Astrophysics Data System (ADS)

    Sarathy, Subram Maniam

    Bioalcohols, such as bioethanol and biobutanol, are suitable replacements for gasoline, while biodiesel can replace petroleum diesel. Improving biofuel engine performance requires understanding its fundamental combustion properties and the pathways of combustion. This study's contribution is experimentally validated chemical kinetic combustion mechanisms for biobutanol and biodiesel. Fundamental combustion data and chemical kinetic mechanisms are presented and discussed to improve our understanding of biofuel combustion. The net environmental impact of biobutanol (i.e., n-butanol) has not been studied extensively, so this study first assesses the sustainability of n-butanol derived from corn. The results indicate that technical advances in fuel production are required before commercializing biobutanol. The primary contribution of this research is new experimental data and a novel chemical kinetic mechanism for n-butanol combustion. The results indicate that under the given experimental conditions, n-butanol is consumed primarily via abstraction of hydrogen atoms to produce fuel radical molecules, which subsequently decompose to smaller hydrocarbon and oxygenated species. The hydroxyl moiety in n-butanol results in the direct production of the oxygenated species such as butanal, acetaldehyde, and formaldehyde. The formation of these compounds sequesters carbon from forming soot precursors, but they may introduce other adverse environmental and health effects. Biodiesel is a mixture of long chain fatty acid methyl esters derived from fats and oils. This research study presents high quality experimental data for one large fatty acid methyl ester, methyl decanoate, and models its combustion using an improved skeletal mechanism. The results indicate that methyl decanoate is consumed via abstraction of hydrogen atoms to produce fuel radicals, which ultimately lead to the production of alkenes. The ester moiety in methyl decanoate leads to the formation of low molecular

  18. Triggering of longitudinal combustion instabilities in solid rocket motors: Nonlinear combustion response

    NASA Technical Reports Server (NTRS)

    Wicker, J. M.; Greene, W. D.; Kim, S. I.; Yang, V.

    1995-01-01

    Pulsed oscillations in solid rocket motors are investigated with emphasis on nonlinear combustion response. The study employs a wave equation governing the unsteady motions in a two-phase flow, and a solution technique based on spatial- and time-averaging. A wide class of combustion response functions is studied to second-order in fluctuation amplitude to determine if, when, and how triggered instabilities arise. Conditions for triggering are derived from analysis of limit cycles, and regions of triggering are found in parametric space. Based on the behavior of model dynamical systems, introduction of linear cross-coupling and quadratic self-coupling among the acoustic modes appears to be the manner in which the nonlinear combustion response produces triggering to a stable limit cycle. Regions of initial conditions corresponding to stable pulses were found, suggesting that stability depends on initial phase angle and harmonic content, as well as the composite amplitude, of the pulse.

  19. 8th International symposium on transport phenomena in combustion

    SciTech Connect

    1995-12-31

    The 8th International Symposium on Transport Phenomena in Combustion will be held in San Francisco, California, U.S.A., July 16-20, 1995, under the auspices of the Pacific Center of Thermal-Fluids Engineering. The purpose of the Symposium is to provide a forum for researchers and practitioners from around the world to present new developments and discuss the state of the art and future directions and priorities in the areas of transport phenomena in combustion. The Symposium is the eighth in a series; previous venues were Honolulu 1985, Tokyo 1987, Taipei 1988, Sydney 1991, Beijing 1992, Seoul 1993 and Acapulco 1994, with emphasis on various aspects of transport phenomena. The current Symposium theme is combustion. The Symposium has assembled a balanced program with topics ranging from fundamental research to contemporary applications of combustion theory. Invited keynote lecturers will provide extensive reviews of topics of great interest in combustion. Colloquia will stress recent advances and innovations in fire spread and suppression, and in low NO{sub x} burners, furnaces, boilers, internal combustion engines, and other practical combustion systems. Finally, numerous papers will contribute to the fundamental understanding of complex processes in combustion. This document contains abstracts of papers to be presented at the Symposium.

  20. Tuned passive control of combustion instabilities using multiple Helmholtz resonators

    NASA Astrophysics Data System (ADS)

    Zhao, Dan; Morgans, A. S.

    2009-03-01

    In this work, tuned passive control is used to damp unstable combustion systems, with particular emphasis on systems which exhibit multiple unstable modes. Helmholtz resonators are used as passive dampers. The frequency at which they offer maximum damping is varied by altering their geometry; in this work, geometry changes are achieved by varying the area of the Helmholtz resonator neck. For each unstable mode exhibited by the combustion system, a separate Helmholtz resonator has its neck area tuned. Two algorithms are developed, one for identifying the characteristics of all modes present in real time, and another for tuning the neck areas of the Helmholtz resonators. These algorithms are successfully implemented in numerical simulations of a longitudinal combustor exhibiting two unstable modes. The algorithms result in both modes being stabilised as long as two Helmholtz resonators are used. Experiments are then conducted on a Rijke tube with its upper part split into two branches of differing lengths, shaped like a 'Y'. The differing lengths give rise to two unstable modes at different frequencies. A Helmholtz resonator is attached to each branch; the neck area of both can be varied by means of an 'iris' valve, which opens and closes like a camera lens. On implementing the procedure for tuning the neck areas, both unstable modes are stabilised, and stability is maintained for large changes in operating condition. This confirms that the procedure developed is sufficiently robust for use in real combustion systems exhibiting multiple unstable modes.

  1. Flow, spray and combustion analysis by laser techniques in the combustion chamber of a direct-injection diesel engine

    NASA Astrophysics Data System (ADS)

    Hentschel, W.; Schindler, K.-P.

    1996-12-01

    The purpose of this paper is to show how the analysis of in -cylinder flow, fuel injection, and combustion by means of state-of-the-art optical techniques, as laser light-sheet, laser doppler anemometry and laser shadowgraphy, can help to support the understanding of the interaction of swirl flow development, spray formation, auto-ignition and combustion in near production-line direct-injection diesel engines and thus advances the development of engines with lower fuel consumption and emissions.

  2. Combustion Dynamics Behavior in a Single-Element Lean Direct Injection (LDI) Gas Turbine Combustor

    DTIC Science & Technology

    2014-06-01

    Technical Paper 3. DATES COVERED (From - To) June 2014- July 2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER In-House Combustion Dynamics Behavior in a...excited combustion dynamics in a model configuration of a lean direct injection (LDI) gas turbine combustor is described. Incoming air temperature and...detailed study of the underlying combustion dynamics mechanisms. First, hydrodynamic modes are investigated by conducting the simulation with an

  3. Modeling Combustion in Supersonic Flows

    NASA Technical Reports Server (NTRS)

    Drummond, J. Philip; Danehy, Paul M.; Bivolaru, Daniel; Gaffney, Richard L.; Tedder, Sarah A.; Cutler, Andrew D.

    2007-01-01

    This paper discusses the progress of work to model high-speed supersonic reacting flow. The purpose of the work is to improve the state of the art of CFD capabilities for predicting the flow in high-speed propulsion systems, particularly combustor flow-paths. The program has several components including the development of advanced algorithms and models for simulating engine flowpaths as well as a fundamental experimental and diagnostic development effort to support the formulation and validation of the mathematical models. The paper will provide details of current work on experiments that will provide data for the modeling efforts along with with the associated nonintrusive diagnostics used to collect the data from the experimental flowfield. Simulation of a recent experiment to partially validate the accuracy of a combustion code is also described.

  4. Supersonic Combustion Research at NASA

    NASA Technical Reports Server (NTRS)

    Drummond, J. P.; Danehy, Paul M.; Gaffney, Richard L., Jr.; Tedder, Sarah A.; Cutler, Andrew D.; Bivolaru, Daniel

    2007-01-01

    This paper discusses the progress of work to model high-speed supersonic reacting flow. The purpose of the work is to improve the state of the art of CFD capabilities for predicting the flow in high-speed propulsion systems, particularly combustor flowpaths. The program has several components including the development of advanced algorithms and models for simulating engine flowpaths as well as a fundamental experimental and diagnostic development effort to support the formulation and validation of the mathematical models. The paper will provide details of current work on experiments that will provide data for the modeling efforts along with the associated nonintrusive diagnostics used to collect the data from the experimental flowfield. Simulation of a recent experiment to partially validate the accuracy of a combustion code is also described.

  5. ACCA College English Teaching Mode

    ERIC Educational Resources Information Center

    Ding, Renlun

    2008-01-01

    This paper elucidates a new college English teaching mode--"ACCA" (Autonomous Cooperative Class-teaching All-round College English Teaching Mode). Integrated theories such as autonomous learning and cooperative learning into one teaching mode, "ACCA", which is being developed and advanced in practice as well, is the achievement…

  6. Catalytic combustion of alcohols for microburner applications

    NASA Astrophysics Data System (ADS)

    Behrens, Douglas A.; Lee, Ivan C.; Waits, C. Michael

    The combustion of energy dense liquid fuels in a catalytic micro-combustor, whose temperatures can be used in energy conversion devices, is an attractive alternative to cumbersome batteries. To miniaturize the reactor, an evaporation model was developed to calculate the minimum distance required for complete droplet vaporization. By increasing the ambient temperature from 298 to 350 K, the distance required for complete evaporation of a 6.5 μm droplet decreases from 3.5 to 0.15 cm. A platinum mesh acted as a preliminary measurement and demonstrated 75% conversion of ethanol. We then selected a more active rhodium-coated alumina foam with a larger surface area and attained 100% conversion of ethanol and 95% conversion of 1-butanol under fuel lean conditions. Effluent post-combustion gas analysis showed that varying the equivalence ratio results in three possible modes of operation. A regime of high carbon selectivity for CO 2 occurs at low equivalence ratios and corresponds to complete combustion with a typical temperature of 775 K that is ideal for PbTe thermoelectric energy conversion devices. Conversely for equivalence ratios greater than 1, carbon selectivity for CO 2 decreases as hydrogen, olefin and paraffin production increases. By tuning the equivalence ratio, we have shown that a single device can combust completely for thermoelectric applications, operate as a fuel reformer to produce hydrogen gas for fuel cells or perform as a bio-refinery for paraffin and olefin synthesis.

  7. Environmentally conscious coal combustion

    SciTech Connect

    Hickmott, D.D.; Brown, L.F.; Currier, R.P.

    1997-08-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project was to evaluate the environmental impacts of home-scale coal combustion on the Navajo Reservation and develop strategies to reduce adverse health effects associated with home-scale coal combustion. Principal accomplishments of this project were: (1) determination of the metal and gaseous emissions of a representative stove on the Navajo Reservation; (2) recognition of cyclic gaseous emissions in combustion in home-scale combustors; (3) `back of the envelope` calculation that home-scale coal combustion may impact Navajo health; and (4) identification that improved coal stoves require the ability to burn diverse feedstocks (coal, wood, biomass). Ultimately the results of Navajo home-scale coal combustion studies will be extended to the Developing World, particularly China, where a significant number (> 150 million) of households continue to heat their homes with low-grade coal.

  8. Combustion chamber noise suppressor

    SciTech Connect

    Livingston, A.M.

    1986-08-19

    A combustion chamber is described for a hot fog generating machine comprising a hollow cylindrical combustion chamber shell having a closure plate at one end and outlet means at the opposite end for directing hot combustion gasses to a fogging nozzle, air inlet means disposed adjacent the outlet means, fuel inlet means and ignition means mounted in the closure plate and liner means disposed concentrically within the cylindrical combustion chamber for controlling the flow of air and combustion gasses within the shell. The liner means includes a liner base having a frustroconical configuration with the smaller diameter end thereof disposed in communication with the outlet means and with the larger diameter end thereof disposed in spaced relation to the shell, circumferentially spaced, longitudinally extending fins extending outwardly from the liner base intermediate the liner base and the shell, a cylindrical liner midsection having circumferentially spaced fins extending outwardly therefrom between the midsection and the shell with the fins supporting the midsection on the larger diameter end of the liner base.

  9. Combustion in fluidized beds

    SciTech Connect

    Dry, F.J.; La Nauze, R.D. )

    1990-07-01

    Circulating fluidized-bed (CFB) combustion systems have become popular since the late 1970s, and, given the current level of activity in the area,it is clear that this technology has a stable future in the boiler market. For standard coal combustion applications, competition is fierce with mature pulverized-fuel-based (PF) technology set to maintain a strong profile. CFB systems, however, can be more cost effective than PF systems when emission control is considered, and, as CFB technology matures, it is expected that an ever-increasing proportion of boiler installations will utilize the CFB concept. CFB systems have advantages in the combustion of low-grade fuels such as coal waste and biomass. In competition with conventional bubbling beds, the CFB boiler often demonstrates superior carbon burn-out efficiency. The key to this combustion technique is the hydrodynamic behavior of the fluidized bed. This article begins with a description of the fundamental fluid dynamic behavior of the CFB system. This is followed by an examination of the combustion process in such an environment and a discussion of the current status of the major CFB technologies.

  10. Combustible structural composites and methods of forming combustible structural composites

    DOEpatents

    Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D.; Swank, W. David

    2013-04-02

    Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

  11. LES of Mild Combustion using Pareto-efficient Combustion Adaptation

    NASA Astrophysics Data System (ADS)

    Wu, Hao; Evans, Michael; Ihme, Matthias

    2015-11-01

    Moderate or Intense Low-Oxygen Dilution (MILD) combustion is a combustion regime that provides opportunities for improved thermal efficiency and reduced pollutant emissions. In this study, large-eddy simulation is used to investigate the ignition, mixing, and stabilization of a jet flame in this kinetics-controlled combustion regime. The combustion process is modeled by a Pareto-efficient combustion (PEC) formulation that optimally combines reaction-transport and chemistry combustion models. In this approach, a three-stream flamelet/progress variable model is used as a computationally efficient description of equilibrated flame regions, and a finite-rate chemistry representation is employed to accurately represent the ignition behavior and flame stabilization. Through comparisons with experiments and simulations with single-regime combustion models, it will be shown that this Pareto-efficient combustion submodel assignment accurately captures important dynamics in complex turbulent flame configurations.

  12. Combustible structural composites and methods of forming combustible structural composites

    DOEpatents

    Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D; Swank, William D.

    2011-08-30

    Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

  13. Thermodynamics and combustion modeling

    NASA Technical Reports Server (NTRS)

    Zeleznik, Frank J.

    1986-01-01

    Modeling fluid phase phenomena blends the conservation equations of continuum mechanics with the property equations of thermodynamics. The thermodynamic contribution becomes especially important when the phenomena involve chemical reactions as they do in combustion systems. The successful study of combustion processes requires (1) the availability of accurate thermodynamic properties for both the reactants and the products of reaction and (2) the computational capabilities to use the properties. A discussion is given of some aspects of the problem of estimating accurate thermodynamic properties both for reactants and products of reaction. Also, some examples of the use of thermodynamic properties for modeling chemically reacting systems are presented. These examples include one-dimensional flow systems and the internal combustion engine.

  14. Internal combustion engine

    DOEpatents

    Baker, Quentin A.; Mecredy, Henry E.; O'Neal, Glenn B.

    1991-01-01

    An improved engine is provided that more efficiently consumes difficult fuels such as coal slurries or powdered coal. The engine includes a precombustion chamber having a portion thereof formed by an ignition plug. The precombustion chamber is arranged so that when the piston is proximate the head, the precombustion chamber is sealed from the main cylinder or the main combustion chamber and when the piston is remote from the head, the precombustion chamber and main combustion chamber are in communication. The time for burning of fuel in the precombustion chamber can be regulated by the distance required to move the piston from the top dead center position to the position wherein the precombustion chamber and main combustion chamber are in communication.

  15. Antipollution combustion chamber

    SciTech Connect

    Caruel, J.E.; Gastebois, P.M.

    1981-01-27

    The invention concerns a combustion chamber for turbojet engines. The combustion chamber is of the annular type and consists of two coaxial flame tubes opening into a common dilution and mixing zone. The inner tube is designed for low operating ratings of the engine, the outer tube for high ratings. Air is injected as far upstream as possible into the dilution zone, to enhance the homogenization of the gaseous flow issuing from the two tubes prior to their passage into the turbine and to assure the optimum radial distribution of temperatures. The combustion chamber according to the invention finds application in a particularly advantageous manner in turbojet engines used in aircraft propulsion because of the reduced emission of pollutants it affords.

  16. Forced cocurrent smoldering combustion

    SciTech Connect

    Dosanjh, S.S.; Pagni, P.J.; Fernandez-Pello, A.C.

    1987-05-01

    An analytic model of the propagation of smoldering combustion through a very porous solid fuel is presented. Here smoldering is initiated at the top of a long, radially insulated, uniform fuel cylinder, so that the smolder wave propagates downward, opposing an upward forced flow of oxidizer. Because the solid fuel and the gaseous oxidizer enter the reaction zone from the same direction, this configuration is referred to as cocurrent (or premixed-flame-like). It is assumed that the propagation of the smolder wave is one-dimensional and steady in a frame of reference moving with the wave. Buoyancy is included and shown to be negligible in the proposed application of a smoldering combustion experiment for use on the Space Shuttle. Radiation heat transfer is incorporated using the diffusion approximation and smoldering combustion is modeled by a finite rate, one-step reaction mechanism.

  17. Fuel Droplet Burning During Droplet Combustion Experiment

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Fuel ignites and burns in the Droplet Combustion Experiment (DCE) on STS-94 on July 4 1997, MET:2/05:40 (approximate). The DCE was designed to investigate the fundamental combustion aspects of single, isolated droplets under different pressures and ambient oxygen concentrations for a range of droplet sizes varying between 2 and 5 mm. DCE used various fuels -- in drops ranging from 1 mm (0.04 inches) to 5 mm (0.2 inches) -- and mixtures of oxidizers and inert gases to learn more about the physics of combustion in the simplest burning configuration, a sphere. The experiment elapsed time is shown at the bottom of the composite image. The DCE principal investigator was Forman Williams, University of California, San Diego. The experiment was part of the space research investigations conducted during the Microgravity Science Laboratory-1R mission (STS-94, July 1-17 1997). Advanced combustion experiments will be a part of investigations plarned for the International Space Station. (1.4MB, 13-second MPEG, screen 320 x 240 pixels; downlinked video, higher quality not available)A still JPG composite of this movie is available at http://mix.msfc.nasa.gov/ABSTRACTS/MSFC-0300168.html.

  18. Combustion characteristics of gas turbine alternative fuels

    NASA Technical Reports Server (NTRS)

    Rollbuhler, R. James

    1987-01-01

    An experimental investigation was conducted to obtain combustion performance values for specific heavyend, synthetic hydrocarbon fuels. A flame tube combustor modified to duplicate an advanced gas turbine engine combustor was used for the tests. Each fuel was tested at steady-state operating conditions over a range of mass flow rates, fuel-to-air mass ratio, and inlet air temperatures. The combustion pressure, as well as the hardware, were kept nearly constant over the program test phase. Test results were obtained in regards to geometric temperature pattern factors as a function of combustor wall temperatures, the combustion gas temperature, and the combustion emissions, both as affected by the mass flow rate and fuel-to-air ratio. The synthetic fuels were reacted in the combustor such that for most tests their performance was as good, if not better, than the baseline gasoline or diesel fuel tests. The only detrimental effects were that at high inlet air temperature conditions, fuel decomposition occurred in the fuel atomizing nozzle passages resulting in blockage. And the nitrogen oxide emissions were above EPA limits at low flow rate and high operating temperature conditions.

  19. Microgravity Combustion Science: 1995 Program Update

    NASA Technical Reports Server (NTRS)

    Ross, Howard D. (Editor); Gokoglu, Suleyman A. (Editor); Friedman, Robert (Editor)

    1995-01-01

    Microgravity greatly benefits the study of fundamental combustion processes. In this environment, buoyancy-induced flow is nearly eliminated, weak or normally obscured forces and flows can be isolated, gravitational settling or sedimentation is nearly eliminated, and temporal and spatial scales can be expanded. This document reviews the state of knowledge in microgravity combustion science with the emphasis on NASA-sponsored developments in the current period of 1992 to early 1995. The subjects cover basic research in gaseous premixed and diffusion-flame systems, flame structure and sooting, liquid droplets and pools, and solid-surface ignition and flame spread. They also cover applied research in combustion synthesis of ceramic-metal composites, advanced diagnostic instrumentation, and on-orbit fire safety. The review promotes continuing research by describing the opportunities for Principal Investigator participation through the NASA Research Announcement program and the available NASA Lewis Research Center ground-based facilities and spaceflight accommodations. This review is compiled by the members and associates of the NASA Lewis Microgravity Combustion Branch, and it serves as an update of two previous overview reports.

  20. Fiber-Supported Droplet Combustion Experiment-2

    NASA Technical Reports Server (NTRS)

    Colantonio, Renato O.

    1998-01-01

    A major portion of the energy produced in the world today comes from the burning of liquid hydrocarbon fuels in the form of droplets. Understanding the fundamental physical processes involved in droplet combustion is not only important in energy production but also in propulsion, in the mitigation of combustion-generated pollution, and in the control of the fire hazards associated with handling liquid combustibles. Microgravity makes spherically symmetric combustion possible, allowing investigators to easily validate their droplet models without the complicating effects of gravity. The Fiber-Supported Droplet Combustion (FSDC-2) investigation was conducted in the Microgravity Glovebox facility of the shuttles' Spacelab during the reflight of the Microgravity Science Laboratory (MSL- 1R) on STS-94 in July 1997. FSDC-2 studied fundamental phenomena related to liquid fuel droplet combustion in air. Pure fuels and mixtures of fuels were burned as isolated single and duo droplets with and without forced air convection. FSDC-2 is sponsored by the NASA Lewis Research Center, whose researchers are working in cooperation with several investigators from industry and academia. The rate at which a droplet burns is important in many commercial applications. The classical theory of droplet burning assumes that, for an isolated, spherically symmetric, single-fuel droplet, the gas-phase combustion processes are much faster than the droplet surface regression rate and that the liquid phase is at a uniform temperature equal to the boiling point. Recent, more advanced models predict that both the liquid and gas phases are unsteady during a substantial portion of the droplet's burning history, thus affecting the instantaneous and average burning rates, and that flame radiation is a dominant mechanism that can extinguish flames in a microgravity environment. FSDC-2 has provided well-defined, symmetric droplet burning data including radiative emissions to validate these theoretical

  1. Studies in combustion dynamics

    SciTech Connect

    Koszykowski, M.L.

    1993-12-01

    The goal of this program is to develop a fundamental understanding and a quantitative predictive capability in combustion modeling. A large part of the understanding of the chemistry of combustion processes comes from {open_quotes}chemical kinetic modeling.{close_quotes} However, successful modeling is not an isolated activity. It necessarily involves the integration of methods and results from several diverse disciplines and activities including theoretical chemistry, elementary reaction kinetics, fluid mechanics and computational science. Recently the authors have developed and utilized new tools for parallel processing to implement the first numerical model of a turbulent diffusion flame including a {open_quotes}full{close_quotes} chemical mechanism.

  2. Alternate Fuels Combustion Research

    DTIC Science & Technology

    1983-10-01

    AFWAL-TR-83-2057 AD A13 8 5 7 5 ALTERNATE FUELS COMBUSTION RESEARCH PHASE RI ’~*~~4 & IWITEY CMAAA * ’s~t:Uwz, ONTARIO October 1983 I•oerls Report...83-2057 P_______________ C TITLE (mod ,,--tt-) 5. TYPE OF REPORT A PERIOD COVERED Alternate Fuels ioahusticn Research Interim Report for Period Phase...I$. KEY WORDS (Continue on reverse sirte it necessear and identify by block number) FUELS ALTERNATE FUELS GAS TURBINE COMBUSTION EXHAUST EMISSIONS 0

  3. Thermal ignition combustion system

    DOEpatents

    Kamo, Roy; Kakwani, Ramesh M.; Valdmanis, Edgars; Woods, Melvins E.

    1988-01-01

    The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m.degree. C. and a specific heat greater than 480 J/kg.degree. C. with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber.

  4. Thermal ignition combustion system

    DOEpatents

    Kamo, R.; Kakwani, R.M.; Valdmanis, E.; Woods, M.E.

    1988-04-19

    The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m C and a specific heat greater than 480 J/kg C with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber. 8 figs.

  5. Transition nozzle combustion system

    DOEpatents

    Kim, Won-Wook; McMahan, Kevin Weston; Maldonado, Jaime Javier

    2016-11-29

    The present application provides a combustion system for use with a cooling flow. The combustion system may include a head end, an aft end, a transition nozzle extending from the head end to the aft end, and an impingement sleeve surrounding the transition nozzle. The impingement sleeve may define a first cavity in communication with the head end for a first portion of the cooling flow and a second cavity in communication with the aft end for a second portion of the cooling flow. The transition nozzle may include a number of cooling holes thereon in communication with the second portion of the cooling flow.

  6. Combustion synthesis of metal-matrix composites. Part 1: The Ti-TiC-Al{sub 2}O{sub 3} system

    SciTech Connect

    Kunrath, A.O.; Strohaecker, T.R.; Moore, J.J.

    1996-01-15

    Combustion synthesis or Self-propagating High-temperature Synthesis (SHS) is a process that involves a reaction which is sufficiently exothermic to sustain itself, and, as such, provides considerable potential for the development of an affordable (low cost), energetically efficient means of producing advanced materials. In the combustion synthesis process, a mix of the reactant powders, pressed into a pellet, is heated to the ignition temperature, Tig, when the exothermic reaction takes place, transforming reactants into products. The heat generated by the reaction raises the temperature of the products to a maximum recorded combustion temperature, Tc, which, under adiabatic conditions, would be the adiabatic temperature, Tad. However, in most combustion reactions, Tc is less than Tad, since heat losses occur from the reaction front. Materials synthesized with each of these combustion modes are typically associated with high levels of porosity, e.g., 50%, which is manifested as both macroporosity and microporosity. Previous work demonstrated that it was possible to decrease the porosity of a TiC-Al{sub 2}O{sub 3}-Ti composite by incorporating an excess liquid metal into the combustion synthesis reaction system. This reaction utilizes aluminothermic reduction of TiO{sub 2} to generate the exothermic condition, and at the same time, uses the required TiO{sub 2}/Al stoichiometry to provide the excess Ti to generate an excess Ti in a matrix of TiC and Al{sub 2}O{sub 3}, each of which are synthesized, in-situ within the overall reaction system.

  7. Toxicology of Biodiesel Combustion products

    EPA Science Inventory

    1. Introduction The toxicology of combusted biodiesel is an emerging field. Much of the current knowledge about biological responses and health effects stems from studies of exposures to other fuel sources (typically petroleum diesel, gasoline, and wood) incompletely combusted. ...

  8. Combuster. [low nitrogen oxide formation

    NASA Technical Reports Server (NTRS)

    Mckay, R. A. (Inventor)

    1978-01-01

    A combuster is provided for utilizing a combustible mixture containing fuel and air, to heat a load fluid such as water or air, in a manner that minimizes the formation of nitrogen oxide. The combustible mixture passes through a small diameter tube where the mixture is heated to its combustion temperature, while the load fluid flows past the outside of the tube to receive heat. The tube is of a diameter small enough that the combustible mixture cannot form a flame, and yet is not subject to wall quench, so that combustion occurs, but at a temperature less than under free flame conditions. Most of the heat required for heating the combustible mixture to its combustion temperature, is obtained from heat flow through the walls of the pipe to the mixture.

  9. Combustion Gas Heating Tests of C/C Composites Coated with SiC Layer

    NASA Astrophysics Data System (ADS)

    Sato, Masaki; Moriya, Shin-ichi; Sato, Masahiro; Tadano, Makoto; Kusaka, Kazuo; Hasegawa, Keiichi; Kumakawa, Akinaga; Yoshida, Makoto

    2008-02-01

    In order to examine the applicability of carbon fiber/carbon matrix composites coated with a silicon carbide layer (C/C-SiCs) to an advanced nozzle for the future reusable rocket engines, two series of combustion gas heating tests were conducted using a small rocket combustor. In the first series of heating tests, five different kinds of C/C-SiCs were tested with specimens in the shape of a square plate for material screening. In the second series of heating tests, two selected C/C-SiCs were tested with specimens in the shape of a small nozzle. The effectiveness of an interlayer between a C/C composite and a SiC layer, which was introduced to improve the durability based on the concept of functionally graded materials (FGMs), can be observed. The typical damage mode was also pointed out in the results of heating test using the small nozzle specimens.

  10. Reversed flow fluidized-bed combustion apparatus

    DOEpatents

    Shang, Jer-Yu; Mei, Joseph S.; Wilson, John S.

    1984-01-01

    The present invention is directed to a fluidized-bed combustion apparatus provided with a U-shaped combustion zone. A cyclone is disposed in the combustion zone for recycling solid particulate material. The combustion zone configuration and the recycling feature provide relatively long residence times and low freeboard heights to maximize combustion of combustible material, reduce nitrogen oxides, and enhance sulfur oxide reduction.

  11. Supersonic Free-Jet Combustion in a Ramjet Burner

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J.; Dippold, Vance F., III

    2010-01-01

    A new dual-mode ramjet combustor concept intended for operation over a wide flight Mach number range is described. Subsonic combustion mode is similar to that of a traditional ram combustor which allows operation at higher efficiency, and to lower flight Mach numbers than current dual-mode scramjets. High speed mode is characterized by supersonic combustion in a free-jet that traverses the subsonic combustion chamber to a variable nozzle. The maximum flight Mach number of this scheme is governed largely by the same physics as its classical counterpart. Although a variable combustor exit aperture is required, the need for fuel staging to accommodate the combustion process is eliminated. Local heating from shock-boundary-layer interactions on combustor walls is also eliminated. Given the parallel nature of the present scheme, overall flowpath length is less than that of present dual-mode configurations. Cycle analysis was done to define the flowpath geometry for computational fluid dynamics (CFD) analysis, and then to determine performance based on the CFD results. CFD results for Mach 5, 8, and 12 flight conditions indicate stable supersonic free-jet formation and nozzle reattachment, thereby establishing the basic feasibility of the concept. These results also reveal the structure of, and interactions between the free-jet and recirculating combustion chamber flows. Performance based on these CFD results is slightly less than that of the constant-pressure-combustion cycle analysis primarily due to these interactions. These differences are quantified and discussed. Additional CFD results at the Mach 8 flight condition show the effects of nozzle throat area variation on combustion chamber pressure, flow structure, and performance. Calculations with constant temperature walls were also done to evaluate heat flux and overall heat loads. Aspects of the concept that warrant further study are outlined. These include diffuser design, ramjet operation, mode transition, loss

  12. Combustible dust tests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sugar dust explosion in Georgia on February 7, 2008 killed 14 workers and injured many others (OSHA, 2009). As a consequence of this explosion, OSHA revised its Combustible Dust National Emphasis (NEP) program. The NEP targets 64 industries with more than 1,000 inspections and has found more tha...

  13. Combustion Fundamentals Research

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The various physical processes that occur in the gas turbine combustor and the development of analytical models that accurately describe these processes are discussed. Aspects covered include fuel sprays; fluid mixing; combustion dynamics; radiation and chemistry and numeric techniques which can be applied to highly turbulent, recirculating, reacting flow fields.

  14. WASTE COMBUSTION SYSTEM ANALYSIS

    EPA Science Inventory

    The report gives results of a study of biomass combustion alternatives. The objective was to evaluate the thermal performance and costs of available and developing biomass systems. The characteristics of available biomass fuels were reviewed, and the performance parameters of alt...

  15. Spray combustion stability project

    NASA Technical Reports Server (NTRS)

    Jeng, San-Mou; Litchford, Ron J.

    1992-01-01

    This report summarizes research activity on the Spray Combustion Stability Project, characterizes accomplishments and current status, and discusses projected future work. The purpose is to provide a concise conceptual overview of the research effort to date so the reader can quickly assimilate the gist of the research results and place them within the context of their potential impact on liquid rocket engine design technology.

  16. Monopropellant combustion system

    NASA Technical Reports Server (NTRS)

    Berg, Gerald R. (Inventor); Mueller, Donn C. (Inventor); Parish, Mark W. (Inventor)

    2005-01-01

    An apparatus and method are provided for decomposition of a propellant. The propellant includes an ionic salt and an additional fuel. Means are provided for decomposing a major portion of the ionic salt. Means are provided for combusting the additional fuel and decomposition products of the ionic salt.

  17. Coal combustion research

    SciTech Connect

    Daw, C.S.

    1996-06-01

    This section describes research and development related to coal combustion being performed for the Fossil Energy Program under the direction of the Morgantown Energy Technology Center. The key activity involves the application of chaos theory for the diagnosis and control of fossil energy processes.

  18. Control of harmful hydrocarbon species in the exhaust of modern advanced GDI engines

    NASA Astrophysics Data System (ADS)

    Hasan, A. O.; Abu-jrai, A.; Turner, D.; Tsolakis, A.; Xu, H. M.; Golunski, S. E.; Herreros, J. M.

    2016-03-01

    A qualitative and quantitative analysis of toxic but currently non-regulated hydrocarbon compounds ranging from C5-C11, before and after a zoned three-way catalytic converter (TWC) in a modern gasoline direct injection (GDI) engine has been studied using gas chromatography-mass spectrometry (GC-MS). The GDI engine has been operated under conventional and advanced combustion modes, which result in better fuel economy and reduced levels of NOx with respect to standard SI operation. However, these fuel-efficient conditions are more challenging for the operation of a conventional TWC, and could lead to higher level of emissions released to the environment. Lean combustion leads to the reduction in pumping losses, fuel consumption and in-cylinder emission formation rates. However, lean HCCI will lead to high levels of unburnt HCs while the presence of oxygen will lower the TWC efficiency for NOx control. The effect on the catalytic conversion of the hydrocarbon species of the addition of hydrogen upstream the catalyst has been also investigated. The highest hydrocarbon engine-out emissions were produced for HCCI engine operation at low engine load operation. The catalyst was able to remove most of the hydrocarbon species to low levels (below the permissible exposure limits) for standard and most of the advanced combustion modes, except for naphthalene (classified as possibly carcinogenic to humans by the International Agency for Research on Cancer) and methyl-naphthalene (which has the potential to cause lung damage). However, when hydrogen was added upstream of the catalyst, the catalyst conversion efficiency in reducing methyl-naphthalene and naphthalene was increased by approximately 21%. This results in simultaneous fuel economy and environmental benefits from the effective combination of advanced combustion and novel aftertreatment systems.

  19. Fuel properties to enable lifted-flame combustion

    SciTech Connect

    Kurtz, Eric

    2015-03-15

    The Fuel Properties to Enable Lifted-Flame Combustion project responded directly to solicitation DE-FOA-0000239 AOI 1A, Fuels and Lubricants for Advanced Combustion Regimes. This subtopic was intended to encompass clean and highly-efficient, liquid-fueled combustion engines to achieve extremely low engine-out nitrogen oxides (NOx) and particulate matter (PM) as a target and similar efficiency as state-of-the-art direct injection diesel engines. The intent of this project was to identify how fuel properties can be used to achieve controllable Leaner Lifted Flame Combustion (LLFC) with low NOx and PM emissions. Specifically, this project was expected to identify and test key fuel properties to enable LLFC and their compatibility with current fuel systems and to enhance combustion models to capture the effect of fuel properties on advanced combustion. Successful demonstration of LLFC may reduce the need for after treatment devices, thereby reducing costs and improving thermal efficiency. The project team consisted of key technical personnel from Ford Motor Company (FMC), the University of Wisconsin-Madison (UW), Sandia National Laboratories (SNL) and Lawrence Livermore National Laboratories (LLNL). Each partner had key roles in achieving project objectives. FMC investigated fuel properties relating to LLFC and sooting tendency. Together, FMC and UW developed and integrated 3D combustion models to capture fuel property combustion effects. FMC used these modeling results to develop a combustion system and define fuel properties to support a single-cylinder demonstration of fuel-enabled LLFC. UW investigated modeling the flame characteristics and emissions behavior of different fuels, including those with different cetane number and oxygen content. SNL led spray combustion experiments to quantify the effect of key fuel properties on combustion characteristics critical for LLFC, as well as single cylinder optical engine experiments to improve fundamental

  20. A clean coal combustion technology-slagging combustors

    SciTech Connect

    Chang, S. L.; Berry, G. F.

    1989-03-01

    Slagging combustion is an advanced clean coal technology technique characterized by low NOx and SOx emission, high combustion efficiency, high ash removal, simple design and compact size. The design of slagging combustors has operational flexibility for a wide range of applications, including retrofitting boilers, magnetohydrodynamic combustors, coal-fired gas turbines, gasifiers and hazardous waste incinerators. In recent years, developers of slagging combustors have achieved encouraging progress toward the commercialization of this technology. Although there is a diversity of technical approaches among the developers, they all aim for a compact design of pulverized coal combustion with high heat release and sub-stoichiometric combustion regimes of operation to suppress NOx formation, and most aim to capture sulfur by using sorbent injection in the combustor. If the present pace toward commercialization continues, retrofitting boilers of sizes ranging from 20 to 250 MMBtu/hr (5.9 to 73 MWt) may be available for commercial use in the 1990's. 18 refs., 2 figs.

  1. Supercritical droplet combustion and related transport phenomena

    NASA Technical Reports Server (NTRS)

    Yang, Vigor; Hsieh, K. C.; Shuen, J. S.

    1993-01-01

    An overview of recent advances in theoretical analyses of supercritical droplet vaporization and combustion is conducted. Both hydrocarbon and cryogenic liquid droplets over a wide range of thermodynamic states are considered. Various important high-pressure effects on droplet behavior, such as thermodynamic non-ideality, transport anomaly, and property variation, are reviewed. Results indicate that the ambient gas pressure exerts significant control of droplet gasification and burning processes through its influence on fluid transport, gas-liquid interfacial thermodynamics, and chemical reactions. The droplet gasification rate increases progressively with pressure. However, the data for the overall burnout time exhibit a considerable change in the combustion mechanism at the criticl pressure, mainly as a result of reduced mass diffusivity and latent heat of vaporization with increased pressure. The influence of droplet size on the burning characteristics is also noted.

  2. Advanced turbine systems program--conceptual design and product development. Quarterly report, November 1994--January 1995

    SciTech Connect

    1995-02-01

    Research continued in the design and development of advanced gas turbine systems. This report presents progress towards turbine blade development, diffuser development, combustion noise investigations,catalytic combustion development, and diagnostic probe development.

  3. Low emission internal combustion engine

    DOEpatents

    Karaba, Albert M.

    1979-01-01

    A low emission, internal combustion compression ignition engine having a cylinder, a piston movable in the cylinder and a pre-combustion chamber communicating with the cylinder near the top thereof and in which low emissions of NO.sub.x are achieved by constructing the pre-combustion chamber to have a volume of between 70% and 85% of the combined pre-chamber and main combustion chamber volume when the piston is at top dead center and by variably controlling the initiation of fuel injection into the pre-combustion chamber.

  4. Modelling of CWS combustion process

    NASA Astrophysics Data System (ADS)

    Rybenko, I. A.; Ermakova, L. A.

    2016-10-01

    The paper considers the combustion process of coal water slurry (CWS) drops. The physico-chemical process scheme consisting of several independent parallel-sequential stages is offered. This scheme of drops combustion process is proved by the particle size distribution test and research stereomicroscopic analysis of combustion products. The results of mathematical modelling and optimization of stationary regimes of CWS combustion are provided. During modeling the problem of defining possible equilibrium composition of products, which can be obtained as a result of CWS combustion processes at different temperatures, is solved.

  5. Coherent structures in swirling flows and their role in acoustic combustion control

    NASA Astrophysics Data System (ADS)

    Paschereit, Christian Oliver; Gutmark, Ephraim; Weisenstein, Wolfgang

    1999-09-01

    Interaction between flow instabilities and acoustic resonant modes and their effect on heat release were investigated and controlled in an experimental low-emission swirl stabilized combustor. Acoustic boundary conditions of the combustor were modified to excite combustion instability at various axisymmetric and helical unstable modes in a fully premixed combustion. The combustion unstable modes were related to flow instabilities in the recirculating wakelike region on the combustor axis and the separating shear layer at the sudden expansion (dump plane). Flow field measurements were performed in a water tunnel using a simulated combustor configuration. The water tunnel tests demonstrated the existence of several modes of flow instabilities in a highly swirling flow, modes which were shown to affect the combustion process. Mean and turbulent characteristics of the internal and external swirling shear layers were measured and unstable flow modes were identified. Instability modes during combustion were visualized by phase locked images of OH chemiluminescence. The axisymmetric mode showed large variation of the heat release during one cycle, while the helical modes showed variations in the radial location of maximal heat release. Closed loop active control system was employed to suppress the thermoacoustic pressure oscillations and to reduce NOx emissions. Microphone and OH emission detection sensors monitored the combustion process and provided input to the control system. An acoustic source modulated the airflow and thus affected the mixing process and the combustion. Effective suppression of the pressure oscillations and the concomitant reduction of NOx emissions were associated with a reduced coherence of the flow structures which excited the thermoacoustic instability.

  6. Pulsed atmospheric fluidized bed combustion. Final report

    SciTech Connect

    Not Available

    1989-11-01

    In order to verify the technical feasibility of the MTCI Pulsed Atmospheric Fluidized Bed Combustor technology, a laboratory-scale system was designed, built and tested. Important aspects of the operational and performance parameters of the system were established experimentally. A considerable amount of the effort was invested in the initial task of constructing an AFBC that would represent a reasonable baseline against which the performance of the PAFBC could be compared. A summary comparison of the performance and emissions data from the MTCI 2 ft {times} 2 ft facility (AFBC and PAFBC modes) with those from conventional BFBC (taller freeboard and recycle operation) and circulating fluidized bed combustion (CFBC) units is given in Table ES-1. The comparison is for typical high-volatile bituminous coals and sorbents of average reactivity. The values indicated for BFBC and CFBC were based on published information. The AFBC unit that was designed to act as a baseline for the comparison was indeed representative of the larger units even at the smaller scale for which it was designed. The PAFBC mode exhibited superior performance in relation to the AFBC mode. The higher combustion efficiency translates into reduced coal consumption and lower system operating cost; the improvement in sulfur capture implies less sorbent requirement and waste generation and in turn lower operating cost; lower NO{sub x} and CO emissions mean ease of site permitting; and greater steam-generation rate translates into less heat exchange surface area and reduced capital cost. Also, the PAFBC performance generally surpasses those of conventional BFBC, is comparable to CFBC in combustion and NO{sub x} emissions, and is better than CFBC in sulfur capture and CO emissions even at the scaled-down size used for the experimental feasibility tests.

  7. Large eddy simulation of combustion instability in a tripropellant air heater

    NASA Astrophysics Data System (ADS)

    Yuan, Lei; Shen, Chibing

    2016-12-01

    This research is motivated by the issue associated with high frequency combustion instability. Large eddy simulation was performed to investigate spontaneous combustion instability in an air/LO2/C2H5OH tripropellant air heater. The simulation predicts self-excited transverse oscillations. Overall behavior of combustion instability including pressure time histories, mode shapes, Rayleigh index and unsteady response of the injector were studied in detail. Special emphasis was given to the flame behavior, droplet trajectories, pressure evolutions, and formation of large-scale vortical structures during combustion instability in present air heater. Furthermore, in contrast to previous investigations, a new process is identified in the simulation that may feed energy into the acoustic mode and drive combustion instability.

  8. MO-DE-202-00: Image-Guided Interventions: Advances in Intraoperative Imaging, Guidance, and An Emerging Role for Medical Physics in Surgery.

    PubMed

    Siewerdsen, Jeffrey

    2016-06-01

    At least three major trends in surgical intervention have emerged over the last decade: a move toward more minimally invasive (or non-invasive) approach to the surgical target; the development of high-precision treatment delivery techniques; and the increasing role of multi-modality intraoperative imaging in support of such procedures. This symposium includes invited presentations on recent advances in each of these areas and the emerging role for medical physics research in the development and translation of high-precision interventional techniques. The four speakers are: (1) Keyvan Farahani, "Image-guided focused ultrasound surgery and therapy" (2) Jeffrey H. Siewerdsen, "Advances in image registration and reconstruction for image-guided neurosurgery" (3) Tina Kapur, "Image-guided surgery and interventions in the advanced multimodality image-guided operating (AMIGO) suite" (4) Raj Shekhar, "Multimodality image-guided interventions: Multimodality for the rest of us" Learning Objectives: 1. Understand the principles and applications of HIFU in surgical ablation. 2. Learn about recent advances in 3D-2D and 3D deformable image registration in support of surgical safety and precision. 3. Learn about recent advances in model-based 3D image reconstruction in application to intraoperative 3D imaging. 4. Understand the multi-modality imaging technologies and clinical applications investigated in the AMIGO suite. 5. Understand the emerging need and techniques to implement multi-modality image guidance in surgical applications such as neurosurgery, orthopaedic surgery, vascular surgery, and interventional radiology. Research supported by the NIH and Siemens Healthcare.; J. Siewerdsen; Grant Support - National Institutes of Health; Grant Support - Siemens Healthcare; Grant Support - Carestream Health; Advisory Board - Carestream Health; Licensing Agreement - Carestream Health; Licensing Agreement - Elekta Oncology.; T. Kapur, P41EB015898; R. Shekhar, Funding: R42CA137886 and

  9. Valve operating device for internal combustion engine

    SciTech Connect

    Konno, T.; Sugai, T.

    1989-07-04

    This patent describes a valve operating device for an internal combustion engine. It has a pair of rocker arms pivotally mounted on a rocker shaft and separately operable by different cams on a camshaft for different modes of operation of an intake or exhaust valve operatively connected to one of the rocker arms, comprising each rocker arm having a portion with a surface substantially parallel to and confronting the surface of the other rocker arm, coupling means in the portions for selectively coupling the rocker arms including a coupling pin movable in a direction substantially perpendicular to the axis of the rocker arm shaft.

  10. Pulverized coal torch combustion in a furnace with plasma-coal system

    NASA Astrophysics Data System (ADS)

    Messerle, V. E.; Ustimenko, A. B.; Askarova, A. S.; Nagibin, A. O.

    2010-09-01

    Combustion of a pulverized coal torch has been numerically simulated on the basis of the equations of multicomponent turbulent two-phase flows. The results of three-dimensional simulation of conventional and plasma activated coal combustion in a furnace are presented. Computer code Cinar ICE was verified at coal combustion in the experimental furnace with thermal power of 3 MW that was equipped with plasma-fuel system. Operation of the furnace has been studied at the conventional combustion mode and with plasma activation of coal combustion. Influence of plasma activation of combustion on thermotechnical characteristics of the torch and decrease of carbon loss and nitrogen oxides concentration at the furnace outlet has been revealed.

  11. Characterization of Ceramic Matrix Composite Fasteners Exposed in a Combustion Liner Rig Test

    NASA Technical Reports Server (NTRS)

    Verrilli, Michael J.; Brewer, David; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    Combustion tests on SiC/SiC CMC (Ceramic Matrix Composite) components were performed in an aircraft combustion environment using the Rich-burn, Quick-quench, Lean-burn (RQL) sector rig. SiC/SiC fasteners were used to attach several of these components to the metallic rig structure. The effect of combustion exposure on the fastener material was characterized via microstructural examination. Fasteners were also destructively tested, after combustion exposure, and the failure loads of fasteners exposed in the sector rig were compared to those of as-manufactured fasteners. Combustion exposure reduced the fastener failure load by 50% relative to the as-manufactured fasteners for exposure times ranging from 50 to 260 hours. The fasteners exposed in the combustion environment demonstrated failure loads that varied with failure mode. Fasteners that had the highest average failure load, failed in the same manner as the unexposed fasteners.

  12. Combustion-Characteristic-Based Active Thrust Modulation of a Solid Rocket Motor

    NASA Astrophysics Data System (ADS)

    Tanaka, Masafumi; Gaspard, Guillaume; Urakawa, Katsuya

    A new concept of thrust modulation of solid propellant rocket motor is proposed. Some propellants cannot burn at intermediate pressure, while they can burn at lower and higher pressures. When one applies such a propellant to a motor, two combustion modes or two thrust levels are attainable without any change of the nozzle configuration. In the experiments different ignition conditions brought independent two combustion modes (low mode and high mode) in the same motor geometry. Some motors showed a natural transition from low mode to high mode. As an example, the alternative thrust levels were 50 N and 180 N. The natural transition was restricted with use of the partitioned grain. An active transition method was explored by exerting pressure perturbation through a vent hole with a ball valve. The valve system worked for the transition from high mode to low mode, but the reverse transition was not achieved well.

  13. Time Resolved FTIR Analysis of Combustion of Ethanol and Gasoline Combustion in AN Internal Combustion Engine

    NASA Astrophysics Data System (ADS)

    White, Allen R.; Sakai, Stephen; Devasher, Rebecca B.

    2011-06-01

    In order to pursue In Situ measurements in an internal combustion engine, a MegaTech Mark III transparent spark ignition engine was modified with a sapphire combustion chamber. This modification will allow the transmission of infrared radiation for time-resolved spectroscopic measurements by an infrared spectrometer. By using a Step-scan equipped Fourier transform spectrometer, temporally resolved infrared spectral data were acquired and compared for combustion in the modified Mark III engine. Measurements performed with the FTIR system provide insight into the energy transfer vectors that precede combustion and also provides an in situ measurement of the progress of combustion. Measurements were performed using ethanol and gasoline.

  14. Combustion engine system

    NASA Technical Reports Server (NTRS)

    Houseman, John (Inventor); Voecks, Gerald E. (Inventor)

    1986-01-01

    A flow through catalytic reactor which selectively catalytically decomposes methanol into a soot free hydrogen rich product gas utilizing engine exhaust at temperatures of 200 to 650 C to provide the heat for vaporizing and decomposing the methanol is described. The reactor is combined with either a spark ignited or compression ignited internal combustion engine or a gas turbine to provide a combustion engine system. The system may be fueled entirely by the hydrogen rich gas produced in the methanol decomposition reactor or the system may be operated on mixed fuels for transient power gain and for cold start of the engine system. The reactor includes a decomposition zone formed by a plurality of elongated cylinders which contain a body of vapor permeable, methanol decomposition catalyst preferably a shift catalyst such as copper-zinc.

  15. Stratified combustion engine

    SciTech Connect

    Solheim, R.G.

    1987-03-17

    The method is described of operating an internal combustion engine having a cylinder with an inner wall. The method comprises admitting, adjacent to the inner wall of the cylinder, a quantity of substantially pure air in a spirally rapidly rotating layer and directing all of the quantity uniformly coaxially relative to the cylinder and toward and against only the adjacent inner wall of the cylinder, and held thereat by Coanda effect and centrifugal force. This is done while also admitting a quantity of fuel mixture in a non-rotating and non-turbulent manner between the layer of rotating pure air and the longitudinal axis of the cylinder, compressing the rotating pure air and the non-rotating fuel mixture simultaneously and firing the non-rotating fuel mixture and exhausting the products of combustion and pure air uniformly coaxially relative to the cylinder and only from a region adjacent to the inner wall and uniformly and completely from the inner wall.

  16. Dynamic features of combustion

    NASA Technical Reports Server (NTRS)

    Oppenheim, A. K.

    1985-01-01

    The dynamic features of combustion are discussed for four important cases: ignition, inflammation, explosion, and detonation. Ignition, the initiation of a self-sustained exothermic process, is considered in the simplest case of a closed thermodynamic system and its stochastic distribution. Inflammation, the initiation and propagation of self-sustained flames, is presented for turbulent flow. Explosion, the dynamic effects caused by the deposition of exothermic energy in a compressible medium, is illustrated by self-similar blast waves with energy deposition at the front and the adiabatic non-self-similar wave. Detonation, the most comprehensive illustration of all the dynamic effects of combustion, is discussed with a phenomenological account of the development and structure of the wave.

  17. Energy recycling by co-combustion of coal and recovered paint solids from automobile paint operations.

    PubMed

    Suriyawong, Achariya; Magee, Rogan; Peebles, Ken; Biswas, Pratim

    2009-05-01

    During the past decade, there has been substantial interest in recovering energy from many unwanted byproducts from industries and municipalities. Co-combustion of these products with coal seems to be the most cost-effective approach. The combustion process typically results in emissions of pollutants, especially fine particles and trace elements. This paper presents the results of an experimental study of particulate emission and the fate of 13 trace elements (arsenic [As], barium [Ba], cadmium [Cd], chromium [Cr], copper [Cu], cobalt [Co], manganese [Mn], molybdenum [Mo], nickel [Ni], lead [Pb], mercury [Hg], vanadium [V], and zinc [Zn]) during combustion tests of recovered paint solids (RPS) and coal. The emissions from combustions of coal or RPS alone were compared with those of co-combustion of RPS with subbituminous coal. The distribution/partitioning of these toxic elements between a coarse-mode ash (particle diameter [dp] > 0.5 microm), a submicrometer-mode ash (dp < 0.5 microm), and flue gases was also evaluated. Submicrometer particles generated by combustion of RPS alone were lower in concentration and smaller in size than that from combustion of coal. However, co-combustion of RPS and coal increased the formation of submicrometer-sized particles because of the higher reducing environment in the vicinity of burning particles and the higher volatile chlorine species. Hg was completely volatilized in all cases; however, the fraction in the oxidized state increased with co-combustion. Most trace elements, except Zn, were retained in ash during combustion of RPS alone. Mo was mostly retained in all samples. The behavior of elements, except Mn and Mo, varied depending on the fuel samples. As, Ba, Cr, Co, Cu, and Pb were vaporized to a greater extent from cocombustion of RPS and coal than from combustion of either fuel. Evidence of the enrichment of certain toxic elements in submicrometer particles has also been observed for As, Cd, Cr, Cu, and Ni during co-combustion.

  18. Ice nucleation by combustion ash particles at conditions relevant to mixed-phase clouds

    NASA Astrophysics Data System (ADS)

    Umo, N. S.; Murray, B. J.; Baeza-Romero, M. T.; Jones, J. M.; Lea-Langton, A. R.; Malkin, T. L.; O'Sullivan, D.; Neve, L.; Plane, J. M. C.; Williams, A.

    2015-05-01

    Ice-nucleating particles can modify cloud properties with implications for climate and the hydrological cycle; hence, it is important to understand which aerosol particle types nucleate ice and how efficiently they do so. It has been shown that aerosol particles such as natural dusts, volcanic ash, bacteria and pollen can act as ice-nucleating particles, but the ice-nucleating ability of combustion ashes has not been studied. Combustion ashes are major by-products released during the combustion of solid fuels and a significant amount of these ashes are emitted into the atmosphere either during combustion or via aerosolization of bottom ashes. Here, we show that combustion ashes (coal fly ash, wood bottom ash, domestic bottom ash, and coal bottom ash) nucleate ice in the immersion mode at conditions relevant to mixed-phase clouds. Hence, combustion ashes could play an important role in primary ice formation in mixed-phase clouds, especially in clouds that are formed near the emission source of these aerosol particles. In order to quantitatively assess the impact of combustion ashes on mixed-phase clouds, we propose that the atmospheric abundance of combustion ashes should be quantified since up to now they have mostly been classified together with mineral dust particles. Also, in reporting ice residue compositions, a distinction should be made between natural mineral dusts and combustion ashes in order to quantify the contribution of combustion ashes to atmospheric ice nucleation.

  19. Solid Rocket Motor Combustion Instability Modeling in COMSOL Multiphysics

    NASA Technical Reports Server (NTRS)

    Fischbach, S. R.

    2015-01-01

    Combustion instability modeling of Solid Rocket Motors (SRM) remains a topic of active research. Many rockets display violent fluctuations in pressure, velocity, and temperature originating from the complex interactions between the combustion process, acoustics, and steady-state gas dynamics. Recent advances in defining the energy transport of disturbances within steady flow-fields have been applied by combustion stability modelers to improve the analysis framework. Employing this more accurate global energy balance requires a higher fidelity model of the SRM flow-field and acoustic mode shapes. The current industry standard analysis tool utilizes a one dimensional analysis of the time dependent fluid dynamics along with a quasi-three dimensional propellant grain regression model to determine the SRM ballistics. The code then couples with another application that calculates the eigenvalues of the one dimensional homogenous wave equation. The mean flow parameters and acoustic normal modes are coupled to evaluate the stability theory developed and popularized by Culick. The assumption of a linear, non-dissipative wave in a quiescent fluid remains valid while acoustic amplitudes are small and local gas velocities stay below Mach 0.2. The current study employs the COMSOL Multiphysics finite element framework to model the steady flow-field parameters and acoustic normal modes of a generic SRM. This work builds upon previous efforts to verify the use of the acoustic velocity potential equation (AVPE) laid out by Campos. The acoustic velocity potential (psi) describing the acoustic wave motion in the presence of an inhomogeneous steady high-speed flow is defined by, del squared psi - (lambda/c) squared psi - M x [M x del((del)(psi))] - 2((lambda)(M)/c + M x del(M) x (del)(psi) - 2(lambda)(psi)[M x del(1/c)] = 0. with M as the Mach vector, c as the speed of sound, and ? as the complex eigenvalue. The study requires one way coupling of the CFD High Mach Number Flow (HMNF

  20. Supersonic Combustion Ramjet Research

    DTIC Science & Technology

    2012-08-01

    4.2 Ignition, Flameholding, and Flame Propagation in Supersonic Flows ......................... 18 4.2.1 Plasma -Assisted Ignition and Flameholding...high- speed flows), plasma -assisted combustion, flameholding (particularly in a high-speed flow), and development and application of diagnostic...Flameholding, and Flame Propagation in Supersonic Flows 4.2.1 Plasma -Assisted Ignition and Flameholding Key questions that have guided this

  1. Combustion powered linear actuator

    DOEpatents

    Fischer, Gary J.

    2007-09-04

    The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.

  2. Spray combustion stability project

    NASA Technical Reports Server (NTRS)

    Jeng, San-Mou; Litchford, Ron J.

    1990-01-01

    This report summarizes research activity on the Spray Combustion Stability Project, characterizes accomplishments and current status, and discusses projected future work. The purpose is to provide a concise conceptual overview of the research effort so the reader can quickly assimilate the gist of the research results and place them within the context of their potential impact on liquid rocket engine design technology. Therefore, this report does not elaborate on many of the detailed technical aspects of the research program.

  3. Industrial Combustion Coordinated Rulemaking.

    PubMed

    Melton, Lula H

    1996-08-01

    The following article is excerpted from the document Industrial Combustion Coordinated Rulemaking - Proposed Organizational Structure and Process, which is available from the Technology Transfer Network (TTN), a computer bulletin board. To access the TTN, call (919) 541-5742; to obtain help with the TTN, call (919) 541-5384. The Industrial Combustion Coordinated Rulemaking (ICCR) document is evolving, reflecting an ongoing dialogue with various stakeholders; therefore, there may be changes between this article and the ICCR as it is implemented. EPA would like to thank all stakeholders (e.g., representatives from various companies and trade associations, state and local air pollution control agencies, and environmental organizations) who have offered suggestions and comments on development of the ICCR. As mentioned in the implications statement, the overall goal of the ICCR is to develop a unified set of federal air emissions regulations. The proposed ICCR will achieve this goal by: • Obtaining active participation from stakeholders, including environmental groups, regulated industries, and state and local regulatory agencies in all phases of regulatory development. • Coordinating the schedule and approach for development of regulations under Sections 111, 112, and 129 of the Clean Air Act that affect ICI combustion. • Determining the most effective ways to address the environmental issues associated with toxic and criteria pollutants from the range of combustion sources. • More effectively considering interactions among the regulations by analyzing the combined benefits and economic impacts of the group of Section 111, 112, and 129 regulations. • Considering strategies to simplify the regulations and allow flexibility in the methods of compliance while maintaining full environmental benefits.

  4. Combustion Characteristics of Sprays

    DTIC Science & Technology

    1989-08-01

    regarded by implication or otherwise, or in any way licensing the holder or any other person or corporation, or conveying any rights or permission to...00 _’N 1. TI TLE inctuat Security CZaaafication5 Combustion Characteristics of Sprays 12. PERSONAL AUTHOR(S) Sohrab, Siavash H. 13& TYPE OF REPORT...to ?!HF of rich butane/air 3unsen flames. .lso, the rotacion speed and :he oerodic temDeracure fluc:uations of rotacfng ?HF are examined. :’!naily

  5. Combustible Cartridge Case Characterization

    DTIC Science & Technology

    1984-02-01

    University (NYU) has resulted in the selection of two cross-linked melamine / formaldehyde acrylic styrene resin systems that can be used in the beater additive... melamine resin Akaradit II stabilizer 20. ABSTRACT (con) Test coupons of combustible cartridge case material were fabricated using these recommended...and agitated for 30 min before the pH was slowly lowered to 3 with p-toluene sulfonic acid. In order to maintain this pH in the felting tank, it was

  6. Spontaneous combustion of hydrogen

    NASA Technical Reports Server (NTRS)

    Nusselt, Wilhelm; Pothmann, PH

    1923-01-01

    It is shown by the author's experiments that hydrogen which escapes to the atmosphere through openings in the system may burn spontaneously if it contains dust. Purely thermal reasoning can not account for the combustion. It seems to be rather an electrical ignition. In order to determine whether the cause of the spontaneous ignition was thermo-chemical, thermo-mechanical, or thermo-electrical, the experiments in this paper were performed.

  7. Combustion Product Evaluation of Various Charge Sizes and Propellant Formulations

    DTIC Science & Technology

    1989-04-01

    Activity , Advanced Systems Division of Aberdeen Proving Ground, without whose help and cooperation this study could not have been performed...WC844 propellant were subjected to u rather detailed chemical analyses. A large number of trace chemical species, volatile organics and PAHs were...Sampling for PAH Analyses ....................... 18 3.3.8 Combustion Product Sampling From A Bore Evacuator, 155 mm Gun

  8. The Diesel Combustion Collaboratory: Combustion Researchers Collaborating over the Internet

    SciTech Connect

    C. M. Pancerella; L. A. Rahn; C. Yang

    2000-02-01

    The Diesel Combustion Collaborator (DCC) is a pilot project to develop and deploy collaborative technologies to combustion researchers distributed throughout the DOE national laboratories, academia, and industry. The result is a problem-solving environment for combustion research. Researchers collaborate over the Internet using DCC tools, which include: a distributed execution management system for running combustion models on widely distributed computers, including supercomputers; web-accessible data archiving capabilities for sharing graphical experimental or modeling data; electronic notebooks and shared workspaces for facilitating collaboration; visualization of combustion data; and video-conferencing and data-conferencing among researchers at remote sites. Security is a key aspect of the collaborative tools. In many cases, the authors have integrated these tools to allow data, including large combustion data sets, to flow seamlessly, for example, from modeling tools to data archives. In this paper the authors describe the work of a larger collaborative effort to design, implement and deploy the DCC.

  9. Internal combustion engine using premixed combustion of stratified charges

    DOEpatents

    Marriott, Craig D.; Reitz, Rolf D. (Madison, WI

    2003-12-30

    During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

  10. First observation of a new zonal-flow cycle state in the H-mode transport barrier of the experimental advanced superconducting Tokamak

    SciTech Connect

    Xu, G. S.; Wang, H. Q.; Wan, B. N.; Guo, H. Y.; Zhang, W.; Chang, J. F.; Wang, L.; Chen, R.; Liu, S. C.; Ding, S. Y.; Shao, L. M.; Xiong, H.; Naulin, V.; Diamond, P. H.; Tynan, G. R.; Xu, M.; Yan, N.; Zhao, H. L.

    2012-12-15

    A new turbulence-flow cycle state has been discovered after the formation of a transport barrier in the H-mode plasma edge during a quiescent phase on the EAST superconducting tokamak. Zonal-flow modulation of high-frequency-broadband (0.05-1 MHz) turbulence was observed in the steep-gradient region leading to intermittent transport events across the edge transport barrier. Good confinement (H{sub 98y,2} {approx} 1) has been achieved in this state, even with input heating power near the L-H transition threshold. A novel model based on predator-prey interaction between turbulence and zonal flows reproduced this state well.

  11. Device for improved combustion

    SciTech Connect

    Polomchak, R.W.; Yacko, M.

    1988-03-08

    A device for improved combustion is described comprising: a tubular housing member having a first end and a second end, the first and second ends each having a circular opening therethrough; a combustion chamber disposed about the second end of the-tubular-housing member; a first conduit member extending from the first end of the tubular housing member and in fluid communication with the circular opening in the first end of the tubular housing member so as to allow the passage of air therethrough; a second conduit member axially disposed within the first conduit member and extending through the first conduit member and through the tubular housing member to the circular opening the second end of the tubular housing member so as to allow the passage of fuel therethrough; means for effecting turbulence in the air passing through the tubular housing member; means for effecting turbulence in the fuel passing through the second conduit member; means for intermixing and emitting the turbulent air and the fuel in a mushroom shaped configuration with the turbulent air surrounding the mushroom shaped configuration so as to substantially eliminate noxious waste gases as by-product of combustion of the air and fuel mixture.

  12. Strobes: an oscillatory combustion.

    PubMed

    Corbel, Justine M L; Lingen, Joost N J; Zevenbergen, John F; Gijzeman, Onno L J; Meijerink, Andries

    2012-04-26

    Strobe compositions belong to the class of solid combustions. They are mixtures of powdered ingredients. When ignited, the combustion front evolves in an oscillatory fashion, and flashes of light are produced by intermittence. They have fascinated many scientists since their discovery at the beginning of the 20th century. However, the chemical and physical processes involved in this curious oscillatory combustion remain unknown. Several theories have been proposed: One claims that two different reactions occur: one during the slow dark phase and another during the fast flash phase. The alternation between the phases is ascribed to heat variations. Other theories suggest that the formation of intermediate species during the dark phase and the change of phase are caused by variations in their concentration. A ternary strobe composition with ammonium perchlorate, magnalium, and barium sulfate is analyzed. The role of barium sulfate is studied by replacing it by other metal sulfates that have different physical properties (melting points), and the burning of the compositions is recorded with a high-speed camera and a spectrometer coupled with a charge-coupled device (CCD) camera. Experimental results show noticeable differences in the physical and chemical processes involved in the strobe reactions.

  13. Droplet Combustion Experiment (DCE)

    NASA Technical Reports Server (NTRS)

    Haggard, John B., Jr.; Nayagan, Vedha; Dryer, Frederick L.; Williams, Forman A.

    1998-01-01

    The first space-based experiments were performed on the combustion of free, individual liquid fuel droplets in oxidizing atmospheres. The fuel was heptane, with initial droplet diameters ranging about from 1 mm to 4 mm. The atmospheres were mixtures of helium and oxygen, at pressures of 1.00, 0.50 and 0.25 bar, with oxygen mole fractions between 20% and 40%, as well as normal Spacelab cabin air. The temperatures of the atmospheres and of the initial liquid fuel were nominally 300 K. A total of 44 droplets were burned successfully on the two flights, 8 on the shortened STS-83 mission and 36 on STS-94. The results spanned the full range of heptane droplet combustion behavior, from radiative flame extinction at larger droplet diameters in the more dilute atmospheres to diffusive extinction in the less dilute atmospheres, with the droplet disappearing prior to flame extinction at the highest oxygen concentrations. Quasisteady histories of droplet diameters were observed along with unsteady histories of flame diameters. New and detailed information was obtained on burning rates, flame characteristics and soot behavior. The results have motivated new computational and theoretical investigations of droplet combustion, improving knowledge of the chemical kinetics, fluid mechanics and heat and mass transfer processes involved in burning liquid fuels.

  14. Energy Efficient Engine (E3) combustion system component technology performance report

    NASA Technical Reports Server (NTRS)

    Burrus, D. L.; Chahrour, C. A.; Foltz, H. L.; Sabla, P. E.; Seto, S. P.; Taylor, J. R.

    1984-01-01

    The Energy Efficient Engine (E3) combustor effort was conducted as part of the overall NASA/GE E3 Program. This effort included the selection of an advanced double-annular combustion system design. The primary intent of this effort was to evolve a design that meets the stringent emissions and life goals of the E3, as well as all of the usual performance requirements of combustion systems for modern turbofan engines. Numerous detailed design studies were conducted to define the features of the combustion system design. Development test hardware was fabricated, and an extensive testing effort was undertaken to evaluate the combustion system subcomponents in order to verify and refine the design. Technology derived from this effort was incorporated into the engine combustion hardware design. The advanced engine combustion system was then evaluated in component testing to verify the design intent. What evolved from this effort was an advanced combustion system capable of satisfying all of the combustion system design objectives and requirements of the E3.

  15. Active control of combustion instability

    SciTech Connect

    Lang, W.; Poinsot, T.; Candel, S.

    1987-12-01

    The principle of 'antisound' is used to construct a method for the suppression of combustion instabilities. This active instability control (AIC) method uses external acoustic excitation by a loudspeaker to suppress the oscillations of a flame. The excitation signal is provided by a microphone located upstream of the flame. This signal is filtered, processed, amplified, and sent to the loudspeaker. The AIC method is validated on a laboratory combustor. It allows the suppression of all unstable modes of the burner for any operating ratio. The influence of the microphone and loudspeaker locations on the performance of the AIC system is described. For a given configuration, domains of stability, i.e., domains where the AIC system parameters provide suppression of the oscillation, are investigated. Measurements of the electric input of the loudspeaker show that the energy consumption of the AIC system is almost negligible and suggest that this method could be used for industrial combustor stabilization. Finally, a simple model describing the effects of the AIC system is developed and its results compared to the experiment.

  16. Advanced hot gas cleaning system for coal gasification processes

    NASA Astrophysics Data System (ADS)

    Newby, R. A.; Bannister, R. L.

    1994-04-01

    The United States electric industry is entering a period where growth and the aging of existing plants will mandate a decision on whether to repower, add capacity, or do both. The power generation cycle of choice, today, is the combined cycle that utilizes the Brayton and Rankine cycles. The combustion turbine in a combined cycle can be used in a repowering mode or in a greenfield plant installation. Today's fuel of choice for new combined cycle power generation is natural gas. However, due to a 300-year supply of coal within the United States, the fuel of the future will include coal. Westinghouse has supported the development of coal-fueled gas turbine technology over the past thirty years. Working with the U.S. Department of Energy and other organizations, Westinghouse is actively pursuing the development and commercialization of several coal-fueled processes. To protect the combustion turbine and environment from emissions generated during coal conversion (gasification/combustion) a gas cleanup system must be used. This paper reports on the status of fuel gas cleaning technology and describes the Westinghouse approach to developing an advanced hot gas cleaning system that contains component systems that remove particulate, sulfur, and alkali vapors. The basic process uses ceramic barrier filters for multiple cleaning functions.

  17. Diagnostic for two-mode variable valve activation device

    SciTech Connect

    Fedewa, Andrew M

    2014-01-07

    A method is provided for diagnosing a multi-mode valve train device which selectively provides high lift and low lift to a combustion valve of an internal combustion engine having a camshaft phaser actuated by an electric motor. The method includes applying a variable electric current to the electric motor to achieve a desired camshaft phaser operational mode and commanding the multi-mode valve train device to a desired valve train device operational mode selected from a high lift mode and a low lift mode. The method also includes monitoring the variable electric current and calculating a first characteristic of the parameter. The method also includes comparing the calculated first characteristic against a predetermined value of the first characteristic measured when the multi-mode valve train device is known to be in the desired valve train device operational mode.

  18. Combustion research for gas turbine engines

    NASA Technical Reports Server (NTRS)

    Mularz, E. J.; Claus, R. W.

    1985-01-01

    Research on combustion is being conducted at Lewis Research Center to provide improved analytical models of the complex flow and chemical reaction processes which occur in the combustor of gas turbine engines and other aeropropulsion systems. The objective of the research is to obtain a better understanding of the various physical processes that occur in the gas turbine combustor in order to develop models and numerical codes which can accurately describe these processes. Activities include in-house research projects, university grants, and industry contracts and are classified under the subject areas of advanced numerics, fuel sprays, fluid mixing, and radiation-chemistry. Results are high-lighted from several projects.

  19. A statistical combustion phase control approach of SI engines

    NASA Astrophysics Data System (ADS)

    Gao, Jinwu; Wu, Yuhu; Shen, Tielong

    2017-02-01

    In order to maximize the performance of internal combustion engine, combustion phase is usually controlled to track its desired reference. However, suffering from the cyclic variability of combustion, it is difficulty but meaningful to control mean of combustion phase and constrain its variance. As a combustion phase indicator, the location of peak pressure (LPP) is utilized for real-time combustion phase control in this research. The purpose of the proposed method is to ensure the mean of LPP statistically tracks its reference and constrains the standard deviation of LPP distribution. To achieve this, LPP is first calculated based on the cylinder pressure sensor, and its characteristics are analyzed at the steady-state operating condition, then the distribution of LPP is examined online using hypothesis test criterion. On the basis of the presented statistical algorithm, current mean of LPP is applied in the feedback channel for designing spark advance adjustment law, and the stability of closed-loop system is theoretically ensured according to a steady statistical model. Finally, the proposed strategy is verified on a spark ignition gasoline engine.

  20. Practical approaches to field problems of stationary combustion systems

    SciTech Connect

    Lee, S.W.

    1997-09-01

    The CANMET Energy Technology Centre (CETC) business plan dictates collaboration with industrial clients and other government agencies to promote energy efficiency, health and safety, pollution reduction and productivity enhancement. The Advanced Combustion Technologies group of CETC provides consultation to numerous organizations in combustion related areas by conducting laboratory and field investigations of fossil fuel-fired combustion equipment. CETC, with its modern research facilities and technical expertise, has taken this practical approach since the seventies and has assisted many organizations in overcoming field problems and in providing cost saving measures and improved profit margins. This paper presents a few selected research projects conducted for industrial clients in north and central America. The combustion systems investigated are mostly liquid fuel fired, with the exception of the utility boiler which was coal-fired. The key areas involved include fuel quality, fuel storage/delivery system contamination, waste derived oils, crude oil combustion, unacceptable pollutant emissions, ambient soot deposition, slagging, fouling, boiler component degradation, and particulate characterization. Some of the practical approaches taken to remedy these field problems on several combustion systems including residential, commercial and industrial scale units are discussed.

  1. Influencing factors on the mode transition in a dual-mode scramjet

    NASA Astrophysics Data System (ADS)

    Yan, Zhang; Bing, Chen; Gang, Liu; Baoxi, Wei; Xu, Xu

    2014-10-01

    An experimental investigation was performed to characterize the effects of fuel type, injector configuration, inflow total temperature and fuel injection distribution on the mode transition in a dual-mode scramjet combustor. High enthalpy vitiated air was heated to three total temperatures by the hydrogen-oxygen combustion, entering the isolator entrance at a Mach number of 2.0. Fuel was injected through a four-hole aero-ramp or transverse injector, and ignited by a gas-pilot flame. At an inflow stagnation condition of P0=0.85 MPa and T0=1200 K, three combustion modes, namely Pure Scram Mode, Dual-Mode Scram Mode and Dual-Mode Ram Mode, were classified through the wall pressure distributions, one-dimensional performance analysis, and optical visualization. Two critical fuel equivalence ratios were selected to divide three combustion modes. At the lower transition point, ERlc, the transition from Pure Scram Mode to Dual-Mode Scram Mode occurred corresponding to a normalized wall pressure at x/H=2.5 of 0.23; while at the upper transition point, ERuc, the transition from Dual-Mode Scram Mode to Dual-Mode Ram Mode occurred corresponding to a normalized wall pressure at x/H=2.5 of 0.34. The transition width, ERw, was defined as the difference of two transition points. In this limited range, the combustor was operating in the Dual-Mode Scram Mode. The ERuc was estimated based on the Rayleigh flow relation, and the applicability of the analytic equation was testified through a series of experiments with different boundary conditions. The experimental results showed that two transition points in the ethylene case were higher in ER than in the hydrogen case, and the measured ERuc of two fuels were all 2.5 times larger than the predicted values. However, two fuels had little difference on the transition width. Due to the angled injection, two transition points in the aero-ramp case were higher in ER than in the transverse injector case; while the influence of injector

  2. Geotechnical/geochemical characterization of advanced coal process waste streams: Task 2

    SciTech Connect

    Moretti, C.J.; Olson, E.S.

    1992-09-01

    Successful disposal practices for solid wastes produced from advanced coal combustion and coal conversion processes must provide for efficient management of relatively large volumes of wastes in a cost-effective and environmentally safe manner. At present, most coal-utilization solid wastes are disposed of using various types of land-based systems, and it is probable that this disposal mode will continue to be widely used in the future for advanced process wastes. Proper design and operation of land-based disposal systems for coal combustion wastes normally require appropriate waste transfer, storage, and conditioning subsystems at the plant to prepare the waste for transport to an ultimate disposal site. Further, the overall waste management plan should include a by-product marketing program to minimize the amount of waste that will require disposal. In order to properly design and operate waste management systems for advanced coal-utilization processes, a fundamental understanding of the physical properties, chemical and mineral compositions, and leaching behaviors of the wastes is required. In order to gain information about the wastes produced by advanced coal-utilization processes, 55 waste samples from 16 different coal gasification, fluidized-bed coal combustion (FBC), and advanced flue gas scrubbing processes were collected. Thirty-four of these wastes were analyzed for their bulk chemical and mineral compositions and tested for a detailed set of disposal-related physical properties. The results of these waste characterizations are presented in this report. In addition to the waste characterization data, this report contains a discussion of potentially useful waste management practices for advanced coal utilization processes.

  3. Combustion and Engine-Core Noise

    NASA Astrophysics Data System (ADS)

    Ihme, Matthias

    2017-01-01

    The implementation of advanced low-emission aircraft engine technologies and the reduction of noise from airframe, fan, and jet exhaust have made noise contributions from an engine core increasingly important. Therefore, meeting future ambitious noise-reduction goals requires the consideration of engine-core noise. This article reviews progress on the fundamental understanding, experimental analysis, and modeling of engine-core noise; addresses limitations of current techniques; and identifies opportunities for future research. After identifying core-noise contributions from the combustor, turbomachinery, nozzles, and jet exhaust, they are examined in detail. Contributions from direct combustion noise, originating from unsteady combustion, and indirect combustion noise, resulting from the interaction of flow-field perturbations with mean-flow variations in turbine stages and nozzles, are analyzed. A new indirect noise-source contribution arising from mixture inhomogeneities is identified by extending the theory. Although typically omitted in core-noise analysis, the impact of mean-flow variations and nozzle-upstream perturbations on the jet-noise modulation is examined, providing potential avenues for future core-noise mitigation.

  4. Methodology development of a time-resolved in-cylinder fuel oxidation analysis: Homogeneous charge compression ignition combustion study application

    SciTech Connect

    Nowak, L.; Guibert, P.; Cavadias, S.; Dupre, S.; Momique, J.C.

    2008-08-15

    A technique was developed and applied to understand the mechanism of fuel oxidation in an internal combustion engine. This methodology determines the fuel and concentrations of various intermediates during the combustion cycle. A time-resolved measurement of a large number of species is the objective of this work and is achieved by the use of a sampling probe developed in-house. A system featuring an electromagnetically actuated sampling valve with internal N{sub 2} dilution was developed for sampling gases coming from the combustion chamber. Combustion species include O{sub 2}, CO{sub 2}, CO, NO{sub x}, fuel components, and hydrocarbons produced due to incomplete combustion of fuel. Combustion gases were collected and analyzed with the objectives of analysis by an automotive exhaust analyzer, separation by gas chromatography, and detection by flame ionization detection and mass spectrometry. The work presented was processed in a homogeneous charge compression ignition combustion mode context. (author)

  5. Analysis of 5 KHz combustion instabilities in 40K methane/LOX combustion chambers

    NASA Technical Reports Server (NTRS)

    Breisacher, Kevin J.; Priem, Richard J.

    1988-01-01

    In 40K methane/LOX 5 KHz engine tests, (first transverse mode) combustion instabilities observed by Rocketdyne are analyzed using Heidmann and Wieber's vaporization model to include LOX flow oscillations. The LOX flow oscillations are determined by including acoustic waves in the feed system analysis. The major parameter controlling stability is the distance (or time delay) associated with atomizing the LOX stream in the coaxial injection system. Results of the analysis that show the influence of mixture ratio, oxidizer and fuel injection velocities, burning time and combustion chamber/injector dimensions on stability are used to explain the existing data. Calculated results to predict the influence of design changes being made for the next set of experiments are also presented.

  6. Energy Conversion and Combustion Sciences

    DTIC Science & Technology

    2012-03-08

    Rotational /Continuous Detonation • Only Single Initiation needed (Circumvent Initiation/DDT difficulty/loss in PDE ) • 10-100x cycle rate increase • Near...new fuels: 1. Rotational or Continuous Detonation (intense/concentrated combustion); 2. Flameless combustion (distributed combustion process...Steady Exit Flow *CFD Courtesy of NRL Rotational Detonation : (PI: Schauer, AFRL/RZ, working with NRL) Rotational Approach Allows Continuous

  7. [Advances in Lymph Node Metastasis and the Modes of Lymph Node 
Dissection in Early Stage Non-small Cell Lung Caner].

    PubMed

    Ding, Ningning; Mao, Yousheng

    2016-06-20

    Lung cancer ranks the first position in morbidity and mortality among all malignances in China. Non-small cell lung cancer (NSCLC) accounts for nearly 80% of all lung malignancies. Surgical resection is still the current major treatment method for early stage NSCLC. Lymph node stages together with the extent of lymph node dissection directly affect the prognosis. Anatomical lobectomy with systematic mediastinal lymph node dissection have been the standard surgical treatment for NSCLC. However, it is controversial in the extent of lymph node dissection for early stage NSCLC. Accurate nodes stage and the extent of mediatinal nodes dissection affect the peri-operative complications and the prognosis of NSCLC greatly. In the past decade, more and more surgeons demostrated that lobe-specific or selective mediastinal lymph node dissection is suitable for clinical stage I NSCLC, especially the stage Ia lesions, and may become the standard lymph node dissection mode in the future.

  8. Combustion characteristics of husk charcoal

    SciTech Connect

    Shimizu, H.; Kimura, T.; Nishiyama, Y.; Terui, T.

    1984-07-01

    This paper analyzes the factors involved in the extraordinary temperature generation in husk combustion furnaces, and investigates methods of protecting furnaces from heat damage. The combustion characteristics of fixed carbon in rice husks are examined in relation to the air flow rate using different husk charcoals. The theoretical flame temperature in a practical bed was determined from the combustion propagation velocity. It is determined that deviation from the regression line relating the combustion propagation velocity with the specific air flow rate showed a slight correlation with the bulk density of the charcoal samples used.

  9. Microgravity Smoldering Combustion Takes Flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Microgravity Smoldering Combustion (MSC) experiment lifted off aboard the Space Shuttle Endeavour in September 1995 on the STS-69 mission. This experiment is part of series of studies focused on the smolder characteristics of porous, combustible materials in a microgravity environment. Smoldering is a nonflaming form of combustion that takes place in the interior of combustible materials. Common examples of smoldering are nonflaming embers, charcoal briquettes, and cigarettes. The objective of the study is to provide a better understanding of the controlling mechanisms of smoldering, both in microgravity and Earth gravity. As with other forms of combustion, gravity affects the availability of air and the transport of heat, and therefore, the rate of combustion. Results of the microgravity experiments will be compared with identical experiments carried out in Earth's gravity. They also will be used to verify present theories of smoldering combustion and will provide new insights into the process of smoldering combustion, enhancing our fundamental understanding of this frequently encountered combustion process and guiding improvement in fire safety practices.

  10. Flammability of Heterogeneously Combusting Metals

    NASA Technical Reports Server (NTRS)

    Jones, Peter D.

    1998-01-01

    Most engineering materials, including some metals, most notably aluminum, burn in homogeneous combustion. 'Homogeneous' refers to both the fuel and the oxidizer being in the same phase, which is usually gaseous. The fuel and oxidizer are well mixed in the combustion reaction zone, and heat is released according to some relation like q(sub c) = delta H(sub c)c[((rho/rho(sub 0))]exp a)(exp -E(sub c)/RT), Eq. (1) where the pressure exponent a is usually close to unity. As long as there is enough heat released, combustion is sustained. It is useful to conceive of a threshold pressure beyond which there is sufficient heat to keep the temperature high enough to sustain combustion, and beneath which the heat is so low that temperature drains away and the combustion is extinguished. Some materials burn in heterogeneous combustion, in which the fuel and oxidizer are in different phases. These include iron and nickel based alloys, which burn in the liquid phase with gaseous oxygen. Heterogeneous combustion takes place on the surface of the material (fuel). Products of combustion may appear as a solid slag (oxide) which progressively covers the fuel. Propagation of the combustion melts and exposes fresh fuel. Heterogeneous combustion heat release also follows the general form of Eq.(1), except that the pressure exponent a tends to be much less than 1. Therefore, the increase in heat release with increasing pressure is not as dramatic as it is in homogeneous combustion. Although the concept of a threshold pressure still holds in heterogeneous combustion, the threshold is more difficult to identify experimentally, and pressure itself becomes less important relative to the heat transfer paths extant in any specific application. However, the constants C, a, and E(sub c) may still be identified by suitable data reduction from heterogeneous combustion experiments, and may be applied in a heat transfer model to judge the flammability of a material in any particular actual

  11. Hybrid Combustion-Gasification Chemical Looping

    SciTech Connect

    Herbert Andrus; Gregory Burns; John Chiu; Gregory Lijedahl; Peter Stromberg; Paul Thibeault

    2009-01-07

    For the past several years Alstom Power Inc. (Alstom), a leading world-wide power system manufacturer and supplier, has been in the initial stages of developing an entirely new, ultra-clean, low cost, high efficiency power plant for the global power market. This new power plant concept is based on a hybrid combustion-gasification process utilizing high temperature chemical and thermal looping technology The process consists of the oxidation, reduction, carbonation, and calcination of calcium-based compounds, which chemically react with coal, biomass, or opportunity fuels in two chemical loops and one thermal loop. The chemical and thermal looping technology can be alternatively configured as (i) a combustion-based steam power plant with CO{sub 2} capture, (ii) a hybrid combustion-gasification process producing a syngas for gas turbines or fuel cells, or (iii) an integrated hybrid combustion-gasification process producing hydrogen for gas turbines, fuel cells or other hydrogen based applications while also producing a separate stream of CO{sub 2} for use or sequestration. In its most advanced configuration, this new concept offers the promise to become the technology link from today's Rankine cycle steam power plants to tomorrow's advanced energy plants. The objective of this work is to develop and verify the high temperature chemical and thermal looping process concept at a small-scale pilot facility in order to enable AL to design, construct and demonstrate a pre-commercial, prototype version of this advanced system. In support of this objective, Alstom and DOE started a multi-year program, under this contract. Before the contract started, in a preliminary phase (Phase 0) Alstom funded and built the required small-scale pilot facility (Process Development Unit, PDU) at its Power Plant Laboratories in Windsor, Connecticut. Construction was completed in calendar year 2003. The objective for Phase I was to develop the indirect combustion loop with CO{sub 2

  12. Combustion Byproducts Recycling Consortium

    SciTech Connect

    Ziemkiewicz, Paul; Vandivort, Tamara; Pflughoeft-Hassett, Debra; Chugh, Y Paul; Hower, James

    2008-08-31

    Each year, over 100 million tons of solid byproducts are produced by coal-burning electric utilities in the United States. Annual production of flue gas desulfurization (FGD) byproducts continues to increase as the result of more stringent sulfur emission restrictions. In addition, stricter limits on NOx emissions mandated by the 1990 Clean Air Act have resulted in utility burner/boiler modifications that frequently yield higher carbon concentrations in fly ash, which restricts the use of the ash as a cement replacement. Controlling ammonia in ash is also of concern. If newer, “clean coal” combustion and gasification technologies are adopted, their byproducts may also present a management challenge. The objective of the Combustion Byproducts Recycling Consortium (CBRC) is to develop and demonstrate technologies to address issues related to the recycling of byproducts associated with coal combustion processes. A goal of CBRC is that these technologies, by the year 2010, will lead to an overall ash utilization rate from the current 34% to 50% by such measures as increasing the current rate of FGD byproduct use and increasing in the number of uses considered “allowable” under state regulations. Another issue of interest to the CBRC would be to examine the environmental impact of both byproduct utilization and disposal. No byproduct utilization technology is likely to be adopted by industry unless it is more cost-effective than landfilling. Therefore, it is extremely important that the utility industry provide guidance to the R&D program. Government agencies and privatesector organizations that may be able to utilize these materials in the conduct of their missions should also provide input. The CBRC will serve as an effective vehicle for acquiring and maintaining guidance from these diverse organizations so that the proper balance in the R&D program is achieved.

  13. Combustion Branch Website Development

    NASA Technical Reports Server (NTRS)

    Bishop, Eric

    2004-01-01

    The NASA combustion branch is a leader in developing and applying combustion science to focused aerospace propulsion systems concepts. It is widely recognized for unique facilities, analytical tools, and personnel. In order to better communicate the outstanding research being done in this Branch to the public and other research organization, a more substantial website was desired. The objective of this project was to build an up-to-date site that reflects current research in a usable and attractive manner. In order to accomplish this, information was requested from all researchers in the Combustion branch, on their professional skills and on the current projects. This information was used to fill in the Personnel and Research sections of the website. A digital camera was used to photograph all personnel and these photographs were included in the personnel section as well. The design of the site was implemented using the latest web standards: xhtml and external css stylesheets. This implementation conforms to the guidelines recommended by the w3c. It also helps to ensure that the web site is accessible by disabled users, and complies with Section 508 Federal legislation (which mandates that all Federal websites be accessible). Graphics for the new site were generated using the gimp (www.gimp.org) an open-source graphics program similar to Adobe Photoshop. Also, all graphics on the site were of a reasonable size (less than 20k, most less than 2k) so that the page would load quickly. Technologies such as Macromedia Flash and Javascript were avoided, as these only function on some clients which have the proper software installed or enabled. The website was tested on different platforms with many different browsers to ensure there were no compatibility issues. The website was tested on windows with MS IE 6, MSIE 5 , Netscape 7, Mozilla and Opera. On a Mac, the site was tested with MS IE 5 , Netscape 7 and Safari.

  14. Combustion Byproducts Recycling Consortium

    SciTech Connect

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    Each year, over 100 million tons of solid byproducts are produced by coal-burning electric utilities in the United States. Annual production of flue gas desulfurization (FGD) byproducts continues to increase as the result of more stringent sulfur emission restrictions. In addition, stricter limits on NOx emissions mandated by the 1990 Clean Air Act have resulted in utility burner/boiler modifications that frequently yield higher carbon concentrations in fly ash, which restricts the use of the ash as a cement replacement. Controlling ammonia in ash is also of concern. If newer, 'clean coal' combustion and gasification technologies are adopted, their byproducts may also present a management challenge. The objective of the Combustion Byproducts Recycling Consortium (CBRC) is to develop and demonstrate technologies to address issues related to the recycling of byproducts associated with coal combustion processes. A goal of CBRC is that these technologies, by the year 2010, will lead to an overall ash utilization rate from the current 34% to 50% by such measures as increasing the current rate of FGD byproduct use and increasing in the number of uses considered 'allowable' under state regulations. Another issue of interest to the CBRC would be to examine the environmental impact of both byproduct utilization and disposal. No byproduct utilization technology is likely to be adopted by industry unless it is more cost-effective than landfilling. Therefore, it is extremely important that the utility industry provide guidance to the R&D program. Government agencies and private-sector organizations that may be able to utilize these materials in the conduct of their missions should also provide input. The CBRC will serve as an effective vehicle for acquiring and maintaining guidance from these diverse organizations so that the proper balance in the R&D program is achieved.

  15. Development of High Efficiency Clean Combustion Engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines

    SciTech Connect

    Marriott, Craig; Gonzalez, Manual; Russell, Durrett

    2011-06-30

    such as internal dilution level and charge temperature. As a result, HCCI combustion has limited robustness when variables exceed the required narrow ranges determined in this program. HCCI combustion is also not available for the entire range of production engine speeds and loads, (i.e., the dynamic range is limited). Thus, regular SI combustion must be employed for a majority of the full dynamic range of the engine. This degrades the potential fuel economy impact of HCCI combustion. Currently-available combustion control actuators for the simple valve train system engine do not have the authority for continuous air - fuel or torque control for managing the combustion mode transitions between SI and HCCI and thus, require further refinement to meet customer refinement expectations. HCCI combustion control sensors require further development to enable robust long-term HCCI combustion control. Finally, the added technologies required to effectively manage HCCI combustion such as electric cam phasers, central direct fuel injection, cylinder pressure sensing, high-flow exhaust gas recirculation system, etc. add excessive on-engine cost and complexity that erodes the production-viability business

  16. Effects of fuel cetane number on the structure of diesel spray combustion: An accelerated Eulerian stochastic fields method

    NASA Astrophysics Data System (ADS)

    Jangi, Mehdi; Lucchini, Tommaso; Gong, Cheng; Bai, Xue-Song

    2015-09-01

    An Eulerian stochastic fields (ESF) method accelerated with the chemistry coordinate mapping (CCM) approach for modelling spray combustion is formulated, and applied to model diesel combustion in a constant volume vessel. In ESF-CCM, the thermodynamic states of the discretised stochastic fields are mapped into a low-dimensional phase space. Integration of the chemical stiff ODEs is performed in the phase space and the results are mapped back to the physical domain. After validating the ESF-CCM, the method is used to investigate the effects of fuel cetane number on the structure of diesel spray combustion. It is shown that, depending of the fuel cetane number, liftoff length is varied, which can lead to a change in combustion mode from classical diesel spray combustion to fuel-lean premixed burned combustion. Spray combustion with a shorter liftoff length exhibits the characteristics of the classical conceptual diesel combustion model proposed by Dec in 1997 (http://dx.doi.org/10.4271/970873), whereas in a case with a lower cetane number the liftoff length is much larger and the spray combustion probably occurs in a fuel-lean-premixed mode of combustion. Nevertheless, the transport budget at the liftoff location shows that stabilisation at all cetane numbers is governed primarily by the auto-ignition process.

  17. Combustion of White Phosphorus

    NASA Astrophysics Data System (ADS)

    Keiter, Richard L.; Gamage, Chaminda P.

    2001-07-01

    The reaction of white phosphorus with pure oxygen is conveniently and safely demonstrated by carrying out the reaction in a retort that has its open end submerged in water. After filling the retort with oxygen gas, a small amount of white phosphorus is introduced and heated with a hot-plate until it ignites. The spectacular reaction leads to consumption and expulsion of oxygen gas, creation of a partial vacuum in the retort, and back suction of water that extinguishes the combustion. Featured on the Cover

  18. Lithium Combustion: A Review

    DTIC Science & Technology

    1990-12-01

    lithium vapors generated with air formed an intense white flame that produced branched- chain condensation aerosol particles, of concentrations 򓆄 mg/im3...generated chain -aggregate lithium combustion aerosols in dry, COg-free air prior to reaction with 0, 0.10, 0.50, 1.0, 1.75, or 5.0% CO in air at a...In order to burn in gaseous chlorine or in bromine or iodine vapor, lithium needs to be heated. With iodine vapor, the reaction is accompanied by

  19. Hybrid fluidized bed combuster

    DOEpatents

    Kantesaria, Prabhudas P.; Matthews, Francis T.

    1982-01-01

    A first atmospheric bubbling fluidized bed furnace is combined with a second turbulent, circulating fluidized bed furnace to produce heat efficiently from crushed solid fuel. The bed of the second furnace receives the smaller sizes of crushed solid fuel, unreacted limestone from the first bed, and elutriated solids extracted from the flu gases of the first bed. The two-stage combustion of crushed solid fuel provides a system with an efficiency greater than available with use of a single furnace of a fluidized bed.

  20. AIR EMISSIONS FROM SCRAP TIRE COMBUSTION

    EPA Science Inventory

    The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...