Advanced automotive diesel engine system study

NASA Technical Reports Server (NTRS)

1983-01-01

A conceptual study of an advanced automotive diesel engine is discussed. The engine concept selected for vehicle installation was a supercharged 1.4 liter, 4 cylinder spark assisted diesel of 14:1 compression ratio. A compounding unit consisting of a Lysholm compressor and expander is connected to the engine crankshaft by a belt drive. The inlet air charge is heated by the expander exhaust gas via a heat exchanger. Four levels of technology achievement on the selected engine concept were evaluated, from state-of-the-art to the ideal case. This resulted in the fuel economy increasing from 53.2 mpg to 81.7 mpg, and the 0-60 mph time decreasing from 17.6 seconds to 10.9 seconds.

Sensible heat receiver for solar dynamic space power system

NASA Astrophysics Data System (ADS)

Perez-Davis, Marla E.; Gaier, James R.; Petrefski, Chris

A sensible heat receiver is considered which uses a vapor grown carbon fiber-carbon (VGCF/C) composite as the thermal storage medium and which was designed for a 7-kW Brayton engine. This heat receiver stores the required energy to power the system during eclipse in the VGCF/C composite. The heat receiver thermal analysis was conducted through the Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA) software package. The sensible heat receiver compares well with other latent and advanced sensible heat receivers analyzed in other studies, while avoiding the problems associated with latent heat storage salts and liquid metal heat pipes. The concept also satisfies the design requirements for a 7-kW Brayton engine system. The weight and size of the system can be optimized by changes in geometry and technology advances for this new material.

Sensible heat receiver for solar dynamic space power system

NASA Technical Reports Server (NTRS)

Perez-Davis, Marla E.; Gaier, James R.; Petrefski, Chris

1991-01-01

A sensible heat receiver considered in this study uses a vapor grown carbon fiber-carbon (VGCF/C) composite as the thermal storage media and was designed for a 7 kW Brayton engine. The proposed heat receiver stores the required energy to power the system during eclipse in the VGCF/C composite. The heat receiver thermal analysis was conducted through the Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA) software package. The sensible heat receiver compares well with other latent and advanced sensible heat receivers analyzed in other studies while avoiding the problems associated with latent heat storage salts and liquid metal heat pipes. The concept also satisfies the design requirements for a 7 kW Brayton engine system. The weight and size of the system can be optimized by changes in geometry and technology advances for this new material.

Sensible heat receiver for solar dynamic space power system

NASA Technical Reports Server (NTRS)

Perez-Davis, Marla E.; Gaier, James R.; Petrefski, Chris

1991-01-01

A sensible heat receiver is considered which uses a vapor grown carbon fiber-carbon (VGCF/C) composite as the thermal storage medium and which was designed for a 7-kW Brayton engine. This heat receiver stores the required energy to power the system during eclipse in the VGCF/C composite. The heat receiver thermal analysis was conducted through the Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA) software package. The sensible heat receiver compares well with other latent and advanced sensible heat receivers analyzed in other studies, while avoiding the problems associated with latent heat storage salts and liquid metal heat pipes. The concept also satisfies the design requirements for a 7-kW Brayton engine system. The weight and size of the system can be optimized by changes in geometry and technology advances for this new material.

Heat-Flux Sensor For Hot Engine Cylinders

NASA Technical Reports Server (NTRS)

Kim, Walter S.; Barrows, Richard F.; Smith, Floyd A.; Koch, John

1989-01-01

Heat-flux sensor includes buried wire thermocouple and thin-film surface thermocouple, made of platinum and platinum with 13 percent rhodium. Sensor intended for use in ceramic-insulated, low-heat-rejection diesel engine at temperatures of about 1,000 K. Thermocouple junction resists environment in cylinder of advanced high-temperature diesel engine created by depositing overlapping films of Pt and 0.87 Pt/0.13 Rh on iron plug. Plug also contains internal thermocouple.

Experimental Investigation on Thermal Physical Properties of an Advanced Glass Fiber Composite Material

NASA Astrophysics Data System (ADS)

Guangfa, Gao; Yongchi, Li; Zheng, Jing; Shujie, Yuan

Fiber reinforced composite materials were applied widely in aircraft and space vehicles engineering. Aimed to an advanced glass fiber reinforced composite material, a series of experiments for measuring thermal physical properties of this material were conducted, and the corresponding performance curves were obtained through statistic analyzing. The experimental results showed good consistency. And then the thermal physical parameters such as thermal expansion coefficient, engineering specific heat and sublimation heat were solved and calculated. This investigation provides an important foundation for the further research on the heat resistance and thermodynamic performance of this material.

Life prediction methodology for ceramic components of advanced heat engines. Phase 1: Volume 2, Appendices

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-03-01

This volume presents the following appendices: ceramic test specimen drawings and schematics, mixed-mode and biaxial stress fracture of structural ceramics for advanced vehicular heat engines (U. Utah), mode I/mode II fracture toughness and tension/torsion fracture strength of NT154 Si nitride (Brown U.), summary of strength test results and fractography, fractography photographs, derivations of statistical models, Weibull strength plots for fast fracture test specimens, and size functions.

A heat receiver design for solar dynamic space power systems

NASA Technical Reports Server (NTRS)

Baker, Karl W.; Dustin, Miles O.; Crane, Roger

1990-01-01

An advanced heat pipe receiver designed for a solar dynamic space power system is described. The power system consists of a solar concentrator, solar heat receiver, Stirling heat engine, linear alternator and waste heat radiator. The solar concentrator focuses the sun's energy into a heat receiver. The engine and alternator convert a portion of this energy to electric power and the remaining heat is rejected by a waste heat radiator. Primary liquid metal heat pipes transport heat energy to the Stirling engine. Thermal energy storage allows this power system to operate during the shade portion of an orbit. Lithium fluoride/calcium fluoride eutectic is the thermal energy storage material. Thermal energy storage canisters are attached to the midsection of each heat pipe. The primary heat pipes pass through a secondary vapor cavity heat pipe near the engine and receiver interface. The secondary vapor cavity heat pipe serves three important functions. First, it smooths out hot spots in the solar cavity and provides even distribution of heat to the engine. Second, the event of a heat pipe failure, the secondary heat pipe cavity can efficiently transfer heat from other operating primary heat pipes to the engine heat exchanger of the defunct heat pipe. Third, the secondary heat pipe vapor cavity reduces temperature drops caused by heat flow into the engine. This unique design provides a high level of reliability and performance.

Advances in cryogenic engineering. Vols. 37A & 37B - Proceedings of the 1991 Cryogenic Engineering Conference, Univ. of Alabama, Huntsville, June 11-14, 1991

NASA Technical Reports Server (NTRS)

Fast, Ronald W. (Editor)

1991-01-01

The present volume on advances in cryogenic engineering discusses heat and mass transfer in helium, heat transfer in cryogenic fluids, thermoacoustic oscillations, and insulation. Attention is given to applications of superconductivity with reference to magnetic stability and coil protection, cryogenic techniques, and refrigeration for electronics and superconducting systems. Topics addressed include compressors, expanders, and pumps for liquid helium, magnetic refrigerators, pulse tube refrigerators, and cryocoolers. Also examined are properties of cryogenic fluids, cryogenic applications in transportion and space science and technology, and cryogenic instrumentation.

Ceramic technology for advanced heat engines project. Semiannual progress report, April-September 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1986-05-01

An assessment of needs was completed, and a five-year project plan was developed with input from private industry. Objective is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. Focus is on structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. The work described in this report is organized according to the following WBS project elements: management and coordination; materials and processing (monolithics, ceramic composites, thermal and wear coatings, joining); materials design methodology (contact interfaces, newmore » concepts); data base and life prediction (time-dependent behavior, environmental effects, fracture mechanics, NDE development); and technology transfer. This report includes contributions from all currently active project participants.« less

Environmental Barrier Coating Fracture, Fatigue and High-Heat-Flux Durability Modeling and Stochastic Progressive Damage Simulation

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Nemeth, Noel N.

2017-01-01

Advanced environmental barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to protect emerging light-weight SiC/SiC ceramic matrix composite (CMC) engine components, further raising engine operating temperatures and performance. Because the environmental barrier coating systems are critical to the performance, reliability and durability of these hot-section ceramic engine components, a prime-reliant coating system along with established life design methodology are required for the hot-section ceramic component insertion into engine service. In this paper, we have first summarized some observations of high temperature, high-heat-flux environmental degradation and failure mechanisms of environmental barrier coating systems in laboratory simulated engine environment tests. In particular, the coating surface cracking morphologies and associated subsequent delamination mechanisms under the engine level high-heat-flux, combustion steam, and mechanical creep and fatigue loading conditions will be discussed. The EBC compostion and archtechture improvements based on advanced high heat flux environmental testing, and the modeling advances based on the integrated Finite Element Analysis Micromechanics Analysis Code/Ceramics Analysis and Reliability Evaluation of Structures (FEAMAC/CARES) program will also be highlighted. The stochastic progressive damage simulation successfully predicts mud flat damage pattern in EBCs on coated 3-D specimens, and a 2-D model of through-the-thickness cross-section. A 2-parameter Weibull distribution was assumed in characterizing the coating layer stochastic strength response and the formation of damage was therefore modeled. The damage initiation and coalescence into progressively smaller mudflat crack cells was demonstrated. A coating life prediction framework may be realized by examining the surface crack initiation and delamination propagation in conjunction with environmental degradation under high-heat-flux and environment load test conditions.

Thermal Conductivity of Advanced Ceramic Thermal Barrier Coatings Determined by a Steady-state Laser Heat-flux Approach

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Miller, Robert A.

2004-01-01

The development of low conductivity and high temperature capable thermal barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity under future high-performance and low-emission engine heat-flux conditions. In this paper, a unique steady-state CO2 laser (wavelength 10.6 microns) heat-flux approach is described for determining the thermal conductivity and conductivity deduced cyclic durability of ceramic thermal and environmental barrier coating systems at very high temperatures (up to 1700 C) under large thermal gradients. The thermal conductivity behavior of advanced thermal and environmental barrier coatings for metallic and Si-based ceramic matrix composite (CMC) component applications has also been investigated using the laser conductivity approach. The relationships between the lattice and radiation conductivities as a function of heat flux and thermal gradient at high temperatures have been examined for the ceramic coating systems. The steady-state laser heat-flux conductivity approach has been demonstrated as a viable means for the development and life prediction of advanced thermal barrier coatings for future turbine engine applications.

Ceramics potential in automotive powerplants

NASA Technical Reports Server (NTRS)

Mclean, A. F.

1983-01-01

The paper addresses the potential that ceramic materials can play an important role in future automotive powerplants - both advanced heat engines and advanced battery systems. A number of related experimental programs are reviewed including ceramics for gasoline and diesel piston engines, gas turbine and Stirling Engines and sodium-sulfur batteries. A strong integrated program to develop ceramics technology is recommended.

Orbit transfer rocket engine technology program. Phase 2: Advanced engine study

NASA Technical Reports Server (NTRS)

Erickson, C.; Martinez, A.; Hines, B.

1987-01-01

In Phase 2 of the Advanced Engine Study, the Failure Modes and Effects Analysis (FMEA) maintenance-driven engine design, preliminary maintenance plan, and concept for space operable disconnects generated in Phase 1 were further developed. Based on the results of the vehicle contractors Orbit Transfer Vehicle (OTV) Concept Definition and System Analysis Phase A studies, minor revisions to the engine design were made. Additional refinements in the engine design were identified through further engine concept studies. These included an updated engine balance incorporating experimental heat transfer data from the Enhanced Heat Load Thrust Chamber Study and a Rao optimum nozzle contour. The preliminary maintenance plan of Phase 1 was further developed through additional studies. These included a compilation of critical component lives and life limiters and a review of the Space Shuttle Main Engine (SSME) operations and maintenance manual in order to begin outlining the overall maintenance procedures for the Orbit Transfer Vehicle Engine and identifying technology requirements for streamlining space-based operations. Phase 2 efforts also provided further definition to the advanced fluid coupling devices including the selection and preliminary design of a preferred concept and a preliminary test plan for its further development.

Status of the advanced Stirling conversion system project for 25 kW dish Stirling applications

NASA Technical Reports Server (NTRS)

Shaltens, Richard K.; Schreiber, Jeffrey G.

1991-01-01

Heat engines were evaluated for terrestrial Solar Distributed Heat Receivers. The Stirling engine was identified as one of the most promising heat engines for terrestrial applications. Technology development is also conducted for Stirling convertors directed toward a dynamic power source for space applications. Space power requirements include high reliability with very long life, low vibration, and high system efficiency. The free-piston Stirling engine has the potential for future high power space conversion systems, either nuclear or solar powered. Although both applications appear to be quite different, their requirements complement each other.

Survey of manufacturers of high-performance heat engines adaptable to solar applications

NASA Technical Reports Server (NTRS)

Stine, W. B.

1984-01-01

The results of an industry survey made during the summer of 1983 are summarized. The survey was initiated in order to develop an information base on advanced engines that could be used in the solar thermal dish-electric program. Questionnaires inviting responses were sent to 39 companies known to manufacture or integrate externally heated engines. Follow-up telephone communication ensured uniformity of response. It appears from the survey that the technology exists to produce external-heat-addition engines of appropriate size with thermal efficiencies of over 40%. Problem areas are materials and sealing.

Proceedings of the NITINOL Heat Engine Conference, 26-27 September 1978, Silver Spring, Maryland

DTIC Science & Technology

1978-09-27

allowed us to design, build, and test various engine designs, while exploring advanced concepts with computer modeling of motor dynamics and heat exchange ...exclude the effects of element geometi y and other material parameters which affect the heat exchange rate and kinetics of the SRP. 5-3...is in Rference 8. 13. In the present work we exclude the effects of element geometry and other material parameters which affect the heat exchange

IECEC '84: Advanced energy systems - Their role in our future; Proceedings of the Nineteenth Intersociety Energy Conversion Engineering Conference, San Francisco, CA, August 19-24, 1984. Volumes 1, 2, 3, & 4

NASA Astrophysics Data System (ADS)

Among the topics discussed are: advanced energy conversion concepts, power sources for aircraft and spacecraft, alternate fuels for industrial and vehicular applications, biomass-derived fuels, electric vehicle design and development status, electrochemical energy conversion systems, electric power generation cycles, energy-efficient industrial processes, and energy policy and system analysis. Also discussed are advanced methods for energy storage and transport, fossil fuel conversion systems, geothermal energy system development and performance, novel and advanced heat engines, hydrogen fuel-based energy systems, MHD technology development status, nuclear energy systems, solar energy conversion methods, advanced heating and cooling systems, Stirling cycle device development, terrestrial photovoltaic systems, and thermoelectric and thermionic systems.

Methane heat transfer investigation

NASA Technical Reports Server (NTRS)

1984-01-01

Future high chamber pressure LOX/hydrocarbon booster engines require copper base alloy main combustion chamber coolant channels similar to the SSME to provide adequate cooling and reusable engine life. Therefore, it is of vital importance to evaluate the heat transfer characteristics and coking thresholds for LNG (94% methane) cooling, with a copper base alloy material adjacent to he fuel coolant. High pressure methane cooling and coking characteristics recently evaluated at Rocketdyne using stainless steel heated tubes at methane bulk temperatures and coolant wall temperatures typical of advanced engine operation except at lower heat fluxes as limited by the tube material. As expected, there was no coking observed. However, coking evaluations need be conducted with a copper base surface exposed to the methane coolant at higher heat fluxes approaching those of future high chamber pressure engines.

Optimization of automotive Rankine cycle waste heat recovery under various engine operating condition

NASA Astrophysics Data System (ADS)

Punov, Plamen; Milkov, Nikolay; Danel, Quentin; Perilhon, Christelle; Podevin, Pierre; Evtimov, Teodossi

2017-02-01

An optimization study of the Rankine cycle as a function of diesel engine operating mode is presented. The Rankine cycle here, is studied as a waste heat recovery system which uses the engine exhaust gases as heat source. The engine exhaust gases parameters (temperature, mass flow and composition) were defined by means of numerical simulation in advanced simulation software AVL Boost. Previously, the engine simulation model was validated and the Vibe function parameters were defined as a function of engine load. The Rankine cycle output power and efficiency was numerically estimated by means of a simulation code in Python(x,y). This code includes discretized heat exchanger model and simplified model of the pump and the expander based on their isentropic efficiency. The Rankine cycle simulation revealed the optimum value of working fluid mass flow and evaporation pressure according to the heat source. Thus, the optimal Rankine cycle performance was obtained over the engine operating map.

Final design of a free-piston hydraulic advanced Stirling conversion system

NASA Technical Reports Server (NTRS)

Wallace, D. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

1991-01-01

Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

Final design of a free-piston hydraulic advanced Stirling conversion system

NASA Astrophysics Data System (ADS)

Wallace, D. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

Environmental Barrier Coatings for Turbine Engines: A Design and Performance Perspective

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Fox, Dennis S.; Ghosn, Louis; Smialek, James L.; Miller, Robert A.

2009-01-01

Ceramic thermal and environmental barrier coatings (TEBC) for SiC-based ceramics will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. However, the coating long-term durability remains a major concern with the ever-increasing temperature, strength and stability requirements in engine high heat-flux combustion environments, especially for highly-loaded rotating turbine components. Advanced TEBC systems, including nano-composite based HfO2-aluminosilicate and rare earth silicate coatings are being developed and tested for higher temperature capable SiC/SiC ceramic matrix composite (CMC) turbine blade applications. This paper will emphasize coating composite and multilayer design approach and the resulting performance and durability in simulated engine high heat-flux, high stress and high pressure combustion environments. The advances in the environmental barrier coating development showed promise for future rotating CMC blade applications.

Development of an Advanced Flameless Combustion Heat Source Utilizing Methanol

DTIC Science & Technology

2010-07-01

effect until the fuel can receive energy from the flameless combustion elements, either by radiant or exhaust heat. Figure 22 and Figure 23 show one...fragments of dirt and debris reducing its effectiveness . This first prototype allowed useful engineering data to be generated but lacked some of the...DEVELOPMENT OF AN ADVANCED FLAMELESS COMBUSTION HEAT SOURCE UTILIZING METHANOL by Clifford G. Welles Catalytic Devices International, LLC

Advanced stratified charge rotary aircraft engine design study

NASA Technical Reports Server (NTRS)

Badgley, P.; Berkowitz, M.; Jones, C.; Myers, D.; Norwood, E.; Pratt, W. B.; Ellis, D. R.; Huggins, G.; Mueller, A.; Hembrey, J. H.

1982-01-01

A technology base of new developments which offered potential benefits to a general aviation engine was compiled and ranked. Using design approaches selected from the ranked list, conceptual design studies were performed of an advanced and a highly advanced engine sized to provide 186/250 shaft Kw/HP under cruise conditions at 7620/25,000 m/ft altitude. These are turbocharged, direct-injected stratified charge engines intended for commercial introduction in the early 1990's. The engine descriptive data includes tables, curves, and drawings depicting configuration, performance, weights and sizes, heat rejection, ignition and fuel injection system descriptions, maintenance requirements, and scaling data for varying power. An engine-airframe integration study of the resulting engines in advanced airframes was performed on a comparative basis with current production type engines. The results show airplane performance, costs, noise & installation factors. The rotary-engined airplanes display substantial improvements over the baseline, including 30 to 35% lower fuel usage.

An assessment of CFD-based wall heat transfer models in piston engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sircar, Arpan; Paul, Chandan; Ferreyro-Fernandez, Sebastian

The lack of accurate submodels for in-cylinder heat transfer has been identified as a key shortcoming in developing truly predictive, physics-based computational fluid dynamics (CFD) models that can be used to develop combustion systems for advanced high-efficiency, low-emissions engines. Only recently have experimental methods become available that enable accurate near-wall measurements to enhance simulation capability via advancing models. Initial results show crank-angle dependent discrepancies with respect to previously used boundary-layer models of up to 100%. However, available experimental data is quite sparse (only few data points on engine walls) and limited (available measurements are those of heat flux only). Predictivemore » submodels are needed for medium-resolution ("engineering") LES and for unsteady Reynolds-averaged simulations (URANS). Recently, some research groups have performed DNS studies on engine-relevant conditions using simple geometries. These provide very useful data for benchmarking wall heat transfer models under such conditions. Further, a number of new and more sophisticated models have also become available in the literature which account for these engine-like conditions. Some of these have been incorporated while others of a more complex nature, which include solving additional partial differential equations (PDEs) within the thin boundary layer near the wall, are underway. These models will then be tested against the available DNS/experimental data in both SI (spark-ignition) and CI (compression-ignition) engines.« less

Diaphragm Stirling engine heat-actuated heat pump development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ackermann, R.A.; Swenson, P.

1981-01-01

The objective of this program is to develop and demonstrate the performance of a diaphragm Stirling engine heat-actuated heat pump power module. The power module, consisting of a free displacer, resonant Stirling engine, hydraulic transmission, and resonant Rankine refrigerant (F-22) compressor, embodies several innovative concepts in free-piston Stirling engine heat pump design that will advance the state of the art of this technology. Progress is reported in three areas of the program. First, a compressor/engine matching analysis and a stability analysis have shown that the power module, which is representative of a two-degree-of-freedom resonant system, will operate stably over themore » full range of heat pump conditions. Second, a compressor design has evolved that has met criteria for performance and cost; and third, tests employing a hydraulic simulator test rig has shown that the transmission losses are less than had been predicted, and that properly designed and fabricated diaphragms can attain long life.« less

Advanced space solar dynamic receivers

NASA Technical Reports Server (NTRS)

Strumpf, Hal J.; Coombs, Murray G.; Lacy, Dovie E.

1988-01-01

A study has been conducted to generate and evaluate advanced solar heat receiver concepts suitable for orbital application with Brayton and Stirling engine cycles in the 7-kW size range. The generated receiver designs have thermal storage capability (to enable power production during the substantial eclipse period which accompanies typical orbits) and are lighter and smaller than state-of-the-art systems, such as the Brayton solar receiver being designed and developed by AiResearch for the NASA Space Station. Two receiver concepts have been developed in detail: a packed bed receiver and a heat pipe receiver. The packed bed receiver is appropriate for a Brayton engine; the heat pipe receiver is applicable for either a Brayton or Stirling engine. The thermal storage for both concepts is provided by the melting and freezing of a salt. Both receiver concepts offer substantial improvements in size and weight compared to baseline receivers.

Heat pipe technology for advanced rocket thrust chambers

NASA Technical Reports Server (NTRS)

Rousar, D. C.

1971-01-01

The application of heat pipe technology to the design of rocket engine thrust chambers is discussed. Subjects presented are: (1) evaporator wick development, (2) specific heat pipe designs and test results, (3) injector design, fabrication, and cold flow testing, and (4) preliminary thrust chamber design.

Measurement of local high-level, transient surface heat flux

NASA Technical Reports Server (NTRS)

Liebert, Curt H.

1988-01-01

This study is part of a continuing investigation to develop methods for measuring local transient surface heat flux. A method is presented for simultaneous measurements of dual heat fluxes at a surface location by considering the heat flux as a separate function of heat stored and heat conducted within a heat flux gage. Surface heat flux information is obtained from transient temperature measurements taken at points within the gage. Heat flux was determined over a range of 4 to 22 MW/sq m. It was concluded that the method is feasible. Possible applications are for heat flux measurements on the turbine blade surfaces of space shuttle main engine turbopumps and on the component surfaces of rocket and advanced gas turbine engines and for testing sensors in heat flux gage calibrators.

Brayton advanced heat receiver development program

NASA Technical Reports Server (NTRS)

Heidenreich, G. R.; Downing, R. S.; Lacey, Dovie E.

1989-01-01

NASA Lewis Research Center is managing an advanced solar dynamic (ASD) space power program. The objective of the ASD program is to develop small and lightweight solar dynamic systems which show significant improvement in efficiency and specific mass over the baseline design derived from the Space Station Freedom technology. The advanced heat receiver development program is a phased program to design, fabricate and test elements of a 7-kWe heat-receiver/thermal-energy-storage subsystem. Receivers for both Brayton and Stirling heat engines are being developed under separate contracts. Phase I, described here, is the current eighteen month effort to design and perform critical technology experiments on innovative concepts designed to reduce mass without compromising thermal efficiency and reliability.

Automated Heat-Flux-Calibration Facility

NASA Technical Reports Server (NTRS)

Liebert, Curt H.; Weikle, Donald H.

1989-01-01

Computer control speeds operation of equipment and processing of measurements. New heat-flux-calibration facility developed at Lewis Research Center. Used for fast-transient heat-transfer testing, durability testing, and calibration of heat-flux gauges. Calibrations performed at constant or transient heat fluxes ranging from 1 to 6 MW/m2 and at temperatures ranging from 80 K to melting temperatures of most materials. Facility developed because there is need to build and calibrate very-small heat-flux gauges for Space Shuttle main engine (SSME).Includes lamp head attached to side of service module, an argon-gas-recirculation module, reflector, heat exchanger, and high-speed positioning system. This type of automated heat-flux calibration facility installed in industrial plants for onsite calibration of heat-flux gauges measuring fluxes of heat in advanced gas-turbine and rocket engines.

Development of advanced high temperature in-cylinder components and tribological systems for low heat rejection diesel engines, phase 1

NASA Astrophysics Data System (ADS)

Kroeger, C. A.; Larson, H. J.

1992-03-01

Analysis and concept design work completed in Phase 1 have identified a low heat rejection engine configuration with the potential to meet the Heavy Duty Transport Technology program specific fuel consumption goal of 152 g/kW-hr. The proposed engine configuration incorporates low heat rejection, in-cylinder components designed for operation at 24 MPa peak cylinder pressure. Water cooling is eliminated by selective oil cooling of the components. A high temperature lubricant will be required due to increased in-cylinder operating temperatures. A two-stage turbocharger air system with intercooling and aftercooling was selected to meet engine boost and BMEP requirements. A turbocompound turbine stage is incorporated for exhaust energy recovery. The concept engine cost was estimated to be 43 percent higher compared to a Caterpillar 3176 engine. The higher initial engine cost is predicted to be offset by reduced operating costs due the lower fuel consumption.

Development of advanced high temperature in-cylinder components and tribological systems for low heat rejection diesel engines, phase 1

NASA Technical Reports Server (NTRS)

Kroeger, C. A.; Larson, H. J.

1992-01-01

Analysis and concept design work completed in Phase 1 have identified a low heat rejection engine configuration with the potential to meet the Heavy Duty Transport Technology program specific fuel consumption goal of 152 g/kW-hr. The proposed engine configuration incorporates low heat rejection, in-cylinder components designed for operation at 24 MPa peak cylinder pressure. Water cooling is eliminated by selective oil cooling of the components. A high temperature lubricant will be required due to increased in-cylinder operating temperatures. A two-stage turbocharger air system with intercooling and aftercooling was selected to meet engine boost and BMEP requirements. A turbocompound turbine stage is incorporated for exhaust energy recovery. The concept engine cost was estimated to be 43 percent higher compared to a Caterpillar 3176 engine. The higher initial engine cost is predicted to be offset by reduced operating costs due the lower fuel consumption.

Calcium-Magnesium-Aluminosilicate (CMAS) Infiltration and Cyclic Degradations of Thermal and Environmental Barrier Coatings in Thermal Gradients

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan; Smialek, Jim; Miller, Robert A.

2014-01-01

In a continuing effort to develop higher temperature capable turbine thermal barrier and environmental barrier coating systems, Calcium-Magnesium-Aluminosilicate (CMAS) resistance of the advanced coating systems needs to be evaluated and improved. This paper highlights some of NASA past high heat flux testing approaches for turbine thermal and environmental barrier coatings assessments in CMAS environments. One of our current emphases has been focused on the thermal barrier - environmental barrier coating composition and testing developments. The effort has included the CMAS infiltrations in high temperature and high heat flux turbine engine like conditions using advanced laser high heat flux rigs, and subsequently degradation studies in laser heat flux thermal gradient cyclic and isothermal furnace cyclic testing conditions. These heat flux CMAS infiltration and related coating durability testing are essential where appropriate CMAS melting, infiltration and coating-substrate temperature exposure temperature controls can be achieved, thus helping quantify the CMAS-coating interaction and degradation mechanisms. The CMAS work is also playing a critical role in advanced coating developments, by developing laboratory coating durability assessment methodologies in simulated turbine engine conditions and helping establish CMAS test standards in laboratory environments.

Heat exchangers in regenerative gas turbine cycles

NASA Astrophysics Data System (ADS)

Nina, M. N. R.; Aguas, M. P. N.

1985-09-01

Advances in compact heat exchanger design and fabrication together with fuel cost rises continuously improve the attractability of regenerative gas turbine helicopter engines. In this study cycle parameters aiming at reduced specific fuel consumption and increased payload or mission range, have been optimized together with heat exchanger type and size. The discussion is based on a typical mission for an attack helicopter in the 900 kw power class. A range of heat exchangers is studied to define the most favorable geometry in terms of lower fuel consumption and minimum engine plus fuel weight. Heat exchanger volume, frontal area ratio and pressure drop effect on cycle efficiency are considered.

Hypersonic engine seal development at NASA Lewis Research Center

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M.

1994-01-01

NASA Lewis Research Center is developing advanced seal concepts and sealing technology for advanced combined cycle ramjet/scramjet engines being designed for the National Aerospace Plane (NASP). Technologies are being developed for both the dynamic seals that seal the sliding interfaces between articulating engine panels and sidewalls, and for the static seals that seal the heat exchanger to back-up structure interfaces. This viewgraph presentation provides an overview of the candidate engine seal concepts, seal material assessments, and unique test facilities used to assess the leakage and thermal performance of the seal concepts.

Hypersonic engine seal development at NASA Lewis Research Center

NASA Astrophysics Data System (ADS)

Steinetz, Bruce M.

1994-07-01

NASA Lewis Research Center is developing advanced seal concepts and sealing technology for advanced combined cycle ramjet/scramjet engines being designed for the National Aerospace Plane (NASP). Technologies are being developed for both the dynamic seals that seal the sliding interfaces between articulating engine panels and sidewalls, and for the static seals that seal the heat exchanger to back-up structure interfaces. This viewgraph presentation provides an overview of the candidate engine seal concepts, seal material assessments, and unique test facilities used to assess the leakage and thermal performance of the seal concepts.

Thermal and Environmental Barrier Coating Development for Advanced Propulsion Engine Systems

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.; Fox, Dennis S.

2008-01-01

Ceramic thermal and environmental barrier coatings (TEBCs) are used in gas turbine engines to protect engine hot-section components in the harsh combustion environments, and extend component lifetimes. Advanced TEBCs that have significantly lower thermal conductivity, better thermal stability and higher toughness than current coatings will be beneficial for future low emission and high performance propulsion engine systems. In this paper, ceramic coating design and testing considerations will be described for turbine engine high temperature and high-heat-flux applications. Thermal barrier coatings for metallic turbine airfoils and thermal/environmental barrier coatings for SiC/SiC ceramic matrix composite (CMC) components for future supersonic aircraft propulsion engines will be emphasized. Further coating capability and durability improvements for the engine hot-section component applications can be expected by utilizing advanced modeling and design tools.

Thermal Conductivity and Sintering Behavior of Advanced Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2002-01-01

Advanced thermal barrier coatings, having significantly reduced long-term thermal conductivities, are being developed using an approach that emphasizes real-time monitoring of thermal conductivity under conditions that are engine-like in terms of temperatures and heat fluxes. This is in contrast to the traditional approach where coatings are initially optimized in terms of furnace and burner rig durability with subsequent measurement in the as-processed or furnace-sintered condition. The present work establishes a laser high-heat-flux test as the basis for evaluating advanced plasma-sprayed and physical vapor-deposited thermal barrier coatings under the NASA Ultra Efficient Engine Technology (UEET) Program. The candidate coating materials for this program are novel thermal barrier coatings that are found to have significantly reduced thermal conductivities due to an oxide-defect-cluster design. Critical issues for designing advanced low conductivity coatings with improved coating durability are also discussed.

Development of Advanced Low Conductivity Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Miller, Robert A.

2004-01-01

Advanced multi-component, low conductivity oxide thermal barrier coatings have been developed using an approach that emphasizes real-time monitoring of thermal conductivity under conditions that are engine-like in terms of temperatures and heat fluxes. This is in contrast to the traditional approach where coatings are initially optimized in terms of furnace and burner rig durability with subsequent measurement in the as-processed or furnace-sintered condition. The present work establishes a laser high-heat-flux test as the basis for evaluating advanced plasma-sprayed and electron beam-physical vapor deposited (EB-PVD) thermal barrier coatings under the NASA Ultra-Efficient Engine Technology (UEET) Program. The candidate coating materials for this program are novel thermal barrier coatings that are found to have significantly reduced thermal conductivities and improved thermal stability due to an oxide-defect-cluster design. Critical issues for designing advanced low conductivity coatings with improved coating durability are also discussed.

Approximate heating analysis for the windward-symmetry plane of Shuttle-like bodies at large angle of attack

NASA Technical Reports Server (NTRS)

Zoby, E. V.

1981-01-01

An engineering method has been developed for computing the windward-symmetry plane convective heat-transfer rates on Shuttle-like vehicles at large angles of attack. The engineering code includes an approximate inviscid flowfield technique, laminar and turbulent heating-rate expressions, an approximation to account for the variable-entropy effects on the surface heating and the concept of an equivalent axisymmetric body to model the windward-ray flowfields of Shuttle-like vehicles at angles of attack from 25 to 45 degrees. The engineering method is validated by comparing computed heating results with corresponding experimental data measured on Shuttle and advanced transportation models over a wide range of flow conditions and angles of attack from 25 to 40 degrees and also with results of existing prediction techniques. The comparisons are in good agreement.

Ceramics for engines

NASA Technical Reports Server (NTRS)

Kiser, James D.; Levine, Stanley R.; Dicarlo, James A.

1987-01-01

Structural ceramics were under nearly continuous development for various heat engine applications since the early 1970s. These efforts were sustained by the properties that ceramics offer in the areas of high-temperature strength, environmental resistance, and low density and the large benefits in system efficiency and performance that can result. The promise of ceramics was not realized because their brittle nature results in high sensitivity to microscopic flaws and catastrophic fracture behavior. This translated into low reliability for ceramic components and thus limited their application in engines. For structural ceramics to successfully make inroads into the terrestrial heat engine market requires further advances in low cost, net shape fabrication of high reliability components, and improvements in properties such as toughness, and strength. These advances will lead to very limited use of ceramics in noncritical applications in aerospace engines. For critical aerospace applications, an additional requirement is that the components display markedly improved toughness and noncatastrophic or graceful fracture. Thus the major emphasis is on fiber-reinforced ceramics.

Toward improved durability in advanced aircraft engine hot sections

NASA Technical Reports Server (NTRS)

Sokolowski, Daniel E. (Editor)

1989-01-01

The conference on durability improvement methods for advanced aircraft gas turbine hot-section components discussed NASA's Hot Section Technology (HOST) project, advanced high-temperature instrumentation for hot-section research, the development and application of combustor aerothermal models, and the evaluation of a data base and numerical model for turbine heat transfer. Also discussed are structural analysis methods for gas turbine hot section components, fatigue life-prediction modeling for turbine hot section materials, and the service life modeling of thermal barrier coatings for aircraft gas turbine engines.

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.

Development of advanced high-temperature heat flux sensors

NASA Technical Reports Server (NTRS)

Atkinson, W. H.; Strange, R. R.

1982-01-01

Various configurations of high temperature, heat flux sensors were studied to determine their suitability for use in experimental combustor liners of advanced aircraft gas turbine engines. It was determined that embedded thermocouple sensors, laminated sensors, and Gardon gauge sensors, were the most viable candidates. Sensors of all three types were fabricated, calibrated, and endurance tested. All three types of sensors met the fabricability survivability, and accuracy requirements established for their application.

The Effect of Ethanol Addition to Gasoline on Low- and Intermediate-Temperature Heat Release under Boosted Conditions in Kinetically Controlled Engines

NASA Astrophysics Data System (ADS)

Vuilleumier, David Malcolm

The detailed study of chemical kinetics in engines has become required to further advance engine efficiency while simultaneously lowering engine emissions. This push for higher efficiency engines is not caused by a lack of oil, but by efforts to reduce anthropogenic carbon dioxide emissions, that cause global warming. To operate in more efficient manners while reducing traditional pollutant emissions, modern internal combustion piston engines are forced to operate in regimes in which combustion is no longer fully transport limited, and instead is at least partially governed by chemical kinetics of combusting mixtures. Kinetically-controlled combustion allows the operation of piston engines at high compression ratios, with partially-premixed dilute charges; these operating conditions simultaneously provide high thermodynamic efficiency and low pollutant formation. The investigations presented in this dissertation study the effect of ethanol addition on the low-temperature chemistry of gasoline type fuels in engines. These investigations are carried out both in a simplified, fundamental engine experiment, named Homogeneous Charge Compression Ignition, as well as in more applied engine systems, named Gasoline Compression Ignition engines and Partial Fuel Stratification engines. These experimental investigations, and the accompanying modeling work, show that ethanol is an effective scavenger of radicals at low temperatures, and this inhibits the low temperature pathways of gasoline oxidation. Further, the investigations measure the sensitivity of gasoline auto-ignition to system pressure at conditions that are relevant to modern engines. It is shown that at pressures above 40 bar and temperatures below 850 Kelvin, gasoline begins to exhibit Low-Temperature Heat Release. However, the addition of 20% ethanol raises the pressure requirement to 60 bar, while the temperature requirement remains unchanged. These findings have major implications for a range of modern engines. Low-Temperature Heat Release significantly enhances the auto-ignition process, which limits the conditions under which advanced combustion strategies may operate. As these advanced combustion strategies are required to meet emissions and fuel-economy regulations, the findings of this dissertation may benefit and be incorporated into future engine design toolkits, such as detailed chemical kinetic mechanisms.

Development of structural ceramic components for automobile applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawamoto, H.

1995-12-01

Development efforts have been made in automobile technologies on heat engines to improve the power performance, the fuel economy, and so on. It is well recognized that ceramic applications are keys to succeed in such advanced heat engines, because of their good mechanical and thermal properties. This paper discusses present automobile applications of structural ceramic components and the expectations in automobile uses. The strength and reliability of mass-produced components for the engines are described with the manufacturing processes. The future R&D directions are recommended for structural ceramics.

The Stirling Project

NASA Technical Reports Server (NTRS)

1987-01-01

Stirling Engine's advanced technology engine offers multiple advantages, principal among them reduced fuel consumption and lower exhaust emissions than comparable internal combustion auto engines, plus multifuel capability. Stirling can use gasoline, kerosene, diesel fuel, jet fuel, alcohol, methanol, butane and that's not the whole list. Applications include irrigation pumping, heat pumps, and electricity generation for submarine, Earth and space systems.

Adiabatic diesel engine component development: Reference engine for on-highway applications

NASA Technical Reports Server (NTRS)

Hakim, Nabil S.

1986-01-01

The main objectives were to select an advanced low heat rejection diesel reference engine (ADRE) and to carry out systems analysis and design. The ADRE concept selection consisted of: (1) rated point performance optimization; (2) study of various exhaust energy recovery scenarios; (3) components, systems and engine configuration studies; and (4) life cycle cost estimates of the ADRE economic worth. The resulting ADRE design proposed a reciprocator with many advanced features for the 1995 technology demonstration time frame. These included ceramic air gap insulated hot section structural components, high temperature tribology treatments, nonmechanical (camless) valve actuation systems, and elimination of the cylinder head gasket. ADRE system analysis and design resulted in more definition of the engine systems. These systems include: (1) electro-hydraulic valve actuation, (2) electronic common rail injection system; (3) engine electronic control; (4) power transfer for accessory drives and exhaust energy recovery systems; and (5) truck installation. Tribology and performance assessments were also carried out. Finite element and probability of survival analyses were undertaken for the ceramic low heat rejection component.

Advanced subsystems development

NASA Technical Reports Server (NTRS)

Livingston, F. R.

1978-01-01

The concept design for a small (less than 10 MWe) solar thermal electric generating plant was completed using projected 1985 technology. The systems requirements were defined and specified. The components, including an engineering prototype for one 15 kWe module of the generating plant, were conceptually designed. Significant features of the small solar thermal power plant were identified as the following: (1) 15 kWe Stirling-cycle engine/alternator with constant power output; (2) 10 meter point-focusing paraboloidal concentrator with cantilevered cellular glass reflecting panels; (3) primary heat pipe with 800 C output solar cavity receiver; (4) secondary heat pipe with molten salt thermal energy storage unit; (5) electric energy transport system; and (6) advanced battery energy storage capability.

Phase-coherent engineering of electronic heat currents with a Josephson modulator

NASA Astrophysics Data System (ADS)

Fornieri, Antonio; Blanc, Christophe; Bosisio, Riccardo; D'Ambrosio, Sophie; Giazotto, Francesco

In this contribution we report the realization of the first balanced Josephson heat modulator designed to offer full control at the nanoscale over the phase-coherent component of electronic thermal currents. The ability to master the amount of heat transferred through two tunnel-coupled superconductors by tuning their phase difference is the core of coherent caloritronics, and is expected to be a key tool in a number of nanoscience fields, including solid state cooling, thermal isolation, radiation detection, quantum information and thermal logic. Our device provides magnetic-flux-dependent temperature modulations up to 40 mK in amplitude with a maximum of the flux-to-temperature transfer coefficient reaching 200 mK per flux quantum at a bath temperature of 25 mK. Foremost, it demonstrates the exact correspondence in the phase-engineering of charge and heat currents, breaking ground for advanced caloritronic nanodevices such as thermal splitters, heat pumps and time-dependent electronic engines.

High temperature alkali corrosion of ceramics in coal gas: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pickrell, G.R.; Sun, T.; Brown, J.J. Jr.

1994-12-31

There are several ceramic materials which are currently being considered for use as structural elements in coal combustion and coal conversion systems because of their thermal and mechanical properties. These include alumina (refractories, membranes, heat engines); silicon carbide and silicon nitride (turbine engines, internal combustion engines, heat exchangers, particulate filters); zirconia (internal combustion engines, turbine engines, refractories); and mullite and cordierite (particulate filters, refractories, heat exchangers). High temperature alkali corrosion has been known to cause premature failure of ceramic components used in advanced high temperature coal combustion systems such as coal gasification and clean-up, coal fired gas turbines, and highmore » efficiency heat engines. The objective of this research is to systematically evaluate the alkali corrosion resistance of the most commonly used structural ceramics including silicon carbide, silicon nitride, cordierite, mullite, alumina, aluminum titanate, and zirconia. The study consists of identification of the alkali reaction products and determination of the kinetics of the alkali reactions as a function of temperature and time. 145 refs., 29 figs., 12 tabs.« less

Facilities | Argonne National Laboratory

Science.gov Websites

Skip to main content Argonne National Laboratory Toggle Navigation Toggle Search Research Facilities Advanced Powertrain Research Facility Center for Transportation Research Distributed Energy Research Center Engine Research Facility Heat Transfer Laboratory Materials Engineering Research Facility

The Effect of Stabilization Treatments on Disk Alloy CH98

NASA Technical Reports Server (NTRS)

Gayda, John; Gabb, Timothy P.; Ellis, David L.

2003-01-01

Gas turbine engines for future subsonic transports will probably have higher pressure ratios which will require nickelbase superalloy disks with 1300 to 1400 F temperature capability. Several advanced disk alloys are being developed to fill this need. One of these, CH98, is a promising candidate for gas turbine engines and is being studied in NASA s Advanced Subsonic Technology (AST) program. For large disks, residual stresses generated during quenching from solution heat treatments are often reduced by a stabilization heat treatment, in which the disk is heated to 1500 or 1600 F for several hours followed by a static air cool. The reduction in residual stress levels lessens distortion during machining of disks. However, previous work on CH98 has indicated that stabilization treatments can also decrease creep capability. In this study, a systematic variation of stabilization temperature and time was investigated to determine its effect on 1300 F tensile and, more importantly, creep behavior. Dwell crack growth rates were also measured for selected stabilization conditions. As these advanced disk alloys may be given a supersolvus solution or a subsolvus solution heat treatment for a given application, it was decided that both options would be studied.

Ab Initio Assessment of the Thermoelectric Performance of Ruthenium-Doped Gadolinium Orthotantalate

NASA Technical Reports Server (NTRS)

Goldsby, Jon

2016-01-01

Solid state energy harvesting using waste heat available in gas turbine engine, offers potential for power generation to meet growing power needs of aircraft. Thermoelectric material advances offer new opportunities. Weight-optimized integrated turbine engine structure incorporating energy conversion devices.

Thermal and Environmental Barrier Coatings for Advanced Propulsion Engine Systems

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Miller, Robert A.

2004-01-01

Ceramic thermal and environmental barrier coatings (TEBCs) are used in gas turbine engines to protect engine hot-section components in the harsh combustion environments, and extend component lifetimes. For future high performance engines, the development of advanced ceramic barrier coating systems will allow these coatings to be used to simultaneously increase engine operating temperature and reduce cooling requirements, thereby leading to significant improvements in engine power density and efficiency. In order to meet future engine performance and reliability requirements, the coating systems must be designed with increased high temperature stability, lower thermal conductivity, and improved thermal stress and erosion resistance. In this paper, ceramic coating design and testing considerations will be described for high temperature and high-heat-flux engine applications in hot corrosion and oxidation, erosion, and combustion water vapor environments. Further coating performance and life improvements will be expected by utilizing advanced coating architecture design, composition optimization, and improved processing techniques, in conjunction with modeling and design tools.

Heavy-Duty Stoichiometric Compression Ignition Engine with Improved Fuel Economy over Alternative Technologies for Meeting 2010 On-Highway Emission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirby J. Baumgard; Richard E. Winsor

2009-12-31

The objectives of the reported work were: to apply the stoichiometric compression ignition (SCI) concept to a 9.0 liter diesel engine; to obtain engine-out NO{sub x} and PM exhaust emissions so that the engine can meet 2010 on-highway emission standards by applying a three-way catalyst for NO{sub x} control and a particulate filter for PM control; and to simulate an optimize the engine and air system to approach 50% thermal efficiency using variable valve actuation and electric turbo compounding. The work demonstrated that an advanced diesel engine can be operated at stoichiometric conditions with reasonable particulate and NOx emissions atmore » full power and peak torque conditions; calculated that the SCI engine will operate at 42% brake thermal efficiency without advanced hardware, turbocompounding, or waste heat recovery; and determined that EGR is not necessary for this advanced concept engine, and this greatly simplifies the concept.« less

Development of a Thermoacoustic Stirling Engine Technology Demonstrator

NASA Astrophysics Data System (ADS)

Reissner, Alexander; Gerger, Joachim; Hummel, Stefan; Reißig, Jannis; Pawelke, Roland

2014-08-01

Waste heat is a primary source of energy loss in many aerospace and terrestrial applications. FOTEC, an Austrian Research Company located in Wiener Neustadt, is presently developing a micro power converter, promising high efficiencies even for small- scale applications. The converter is based on an innovative thermoacoustic stirling engine concept without any moving parts. Such a maintenance-free engine system would be particularly suitable for advanced space power systems (radioisotope, waste heat) or even within the scope of terrestrial energy harvesting. This paper will summarizes the status of our ongoing efforts on this micro power converter technology.

Advanced hybrid vehicle propulsion system study

NASA Technical Reports Server (NTRS)

Schwarz, R.

1982-01-01

Results are presented of a study of an advanced heat engine/electric automotive hybrid propulsion system. The system uses a rotary stratified charge engine and ac motor/controller in a parallel hybrid configuration. The three tasks of the study were (1) parametric studies involving five different vehicle types, (2) design trade-off studies to determine the influence of various vehicle and propulsion system paramaters on system performance fuel economy and cost, and (3) a conceptual design establishing feasibility at the selected approach. Energy consumption for the selected system was .034 1/km (61.3 mpg) for the heat engine and .221 kWh/km (.356 kWh/mi) for the electric power system over a modified J227 a schedule D driving cycle. Life cycle costs were 7.13 cents/km (11.5 cents/mi) at $2/gal gasoline and 7 cents/kWh electricity for 160,000 km (100,000 mi) life.

EVALUATION OF AN ADVANCED ENGINEERING TEST REACTOR DESIGN

DOE Office of Scientific and Technical Information (OSTI.GOV)

McVey, M.; Bradfute, J.O.; Buck, K.E.

1958-07-15

The scope of the study was primarily concerned with optimization of the geometrical and core-composition variables to achieve maximum flux in the loop region per unit core power without exceeding heat transfer and other engineering limitations. Centain other design questions are to be investigated. (A.C.)

Development of advanced high-temperature heat flux sensors. Phase 2: Verification testing

NASA Technical Reports Server (NTRS)

Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

1985-01-01

A two-phase program is conducted to develop heat flux sensors capable of making heat flux measurements throughout the hot section of gas turbine engines. In Phase 1, three types of heat flux sensors are selected; embedded thermocouple, laminated, and Gardon gauge sensors. A demonstration of the ability of these sensors to operate in an actual engine environment is reported. A segmented liner of each of two combustors being used in the Broad Specification Fuels Combustor program is instrumented with the three types of heat flux sensors then tested in a high pressure combustor rig. Radiometer probes are also used to measure the radiant heat loads to more fully characterize the combustor environment. Test results show the heat flux sensors to be in good agreement with radiometer probes and the predicted data trends. In general, heat flux sensors have strong potential for use in combustor development programs.

solar thermal power systems advanced solar thermal technology project, advanced subsystems development

NASA Technical Reports Server (NTRS)

1979-01-01

The preliminary design for a prototype small (20 kWe) solar thermal electric generating unit was completed, consisting of several subsystems. The concentrator and the receiver collect solar energy and a thermal buffer storage with a transport system is used to provide a partially smoothed heat input to the Stirling engine. A fossil-fuel combustor is included in the receiver designs to permit operation with partial or no solar insolation (hybrid). The engine converts the heat input into mechanical action that powers a generator. To obtain electric power on a large scale, multiple solar modules will be required to operate in parallel. The small solar electric power plant used as a baseline design will provide electricity at remote sites and small communities.

Physiological and engineering study of advanced thermoregulatory systems for extravehicular space suits

NASA Technical Reports Server (NTRS)

Chato, J. C.; Hertig, B. A.

1972-01-01

Investigations of thermal control for extravehicular space suits are reported. The characteristics of independent cooling of temperature and removal of excess heat from separate regions of the body, and the applications of heat pipes in protective suits are discussed along with modeling of the human thermal system.

Intelligent Engine Systems: Thermal Management and Advanced Cooling

NASA Technical Reports Server (NTRS)

Bergholz, Robert

2008-01-01

The objective is to provide turbine-cooling technologies to meet Propulsion 21 goals related to engine fuel burn, emissions, safety, and reliability. Specifically, the GE Aviation (GEA) Advanced Turbine Cooling and Thermal Management program seeks to develop advanced cooling and flow distribution methods for HP turbines, while achieving a substantial reduction in total cooling flow and assuring acceptable turbine component safety and reliability. Enhanced cooling techniques, such as fluidic devices, controlled-vortex cooling, and directed impingement jets, offer the opportunity to incorporate both active and passive schemes. Coolant heat transfer enhancement also can be achieved from advanced designs that incorporate multi-disciplinary optimization of external film and internal cooling passage geometry.

Dual nozzle aerodynamic and cooling analysis study. [dual throat and dual expander nozzles

NASA Technical Reports Server (NTRS)

Meagher, G. M.

1980-01-01

Geometric, aerodynamic flow field, performance prediction, and heat transfer analyses are considered for two advanced chamber nozzle concepts applicable to Earth-to-orbit engine systems. Topics covered include improvements to the dual throat aerodynamic and performance prediction program; geometric and flow field analyses of the dual expander concept; heat transfer analysis of both concepts, and engineering analysis of data from the NASA/MSFC hot-fire testing of a dual throat thruster model thrust chamber assembly. Preliminary results obtained are presented in graphs.

New perspectives for advanced automobile diesel engines

NASA Technical Reports Server (NTRS)

Tozzi, L.; Sekar, R.; Kamo, R.; Wood, J. C.

1983-01-01

Computer simulation results are presented for advanced automobile diesel engine performance. Four critical factors for performance enhancement were identified: (1) part load preheating and exhaust gas energy recovery, (2) fast heat release combustion process, (3) reduction in friction, and (4) air handling system efficiency. Four different technology levels were considered in the analysis. Simulation results are compared in terms of brake specific fuel consumption and vehicle fuel economy in km/liter (miles per gallon). Major critical performance sensitivity areas are: (1) combustion process, (2) expander and compressor efficiency, and (3) part load preheating and compound system. When compared to the state of the art direct injection, cooled, automobile diesel engine, the advanced adiabatic compound engine concept showed the unique potential of doubling the fuel economy. Other important performance criteria such as acceleration, emissions, reliability, durability and multifuel capability are comparable to or better than current passenger car diesel engines.

Performance and Durability of Environmental Barrier Coatings on SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna

2016-01-01

This presentation highlights advanced environmental barrier coating (EBC) and SiC-SiC Ceramic Matrix Composites (CMC) systems for next generation turbine engines. The emphasis will be placed on fundamental coating and CMC property evaluations; and the integrated system performance and degradation mechanisms in simulated laboratory turbine engine testing environments. Long term durability tests in laser rig simulated high heat flux the rmomechanical creep and fatigue loading conditions will also be presented. The results can help improve the future EBC-CMC system designs, validating the advanced EBC-CMC technologies for hot section turbine engine applications.

Research on inverse, hybrid and optimization problems in engineering sciences with emphasis on turbomachine aerodynamics: Review of Chinese advances

NASA Technical Reports Server (NTRS)

Liu, Gao-Lian

1991-01-01

Advances in inverse design and optimization theory in engineering fields in China are presented. Two original approaches, the image-space approach and the variational approach, are discussed in terms of turbomachine aerodynamic inverse design. Other areas of research in turbomachine aerodynamic inverse design include the improved mean-streamline (stream surface) method and optimization theory based on optimal control. Among the additional engineering fields discussed are the following: the inverse problem of heat conduction, free-surface flow, variational cogeneration of optimal grid and flow field, and optimal meshing theory of gears.

Heat Transfer and Thermal Stability Research for Advanced Hydrocarbon Fuel Technologies

NASA Technical Reports Server (NTRS)

DeWitt, Kenneth; Stiegemeier, Benjamin

2005-01-01

In recent years there has been increased interest in the development of a new generation of high performance boost rocket engines. These efforts, which will represent a substantial advancement in boost engine technology over that developed for the Space Shuttle Main Engines in the early 1970s, are being pursued both at NASA and the United States Air Force. NASA, under its Space Launch Initiative s Next Generation Launch Technology Program, is investigating the feasibility of developing a highly reliable, long-life, liquid oxygen/kerosene (RP-1) rocket engine for launch vehicles. One of the top technical risks to any engine program employing hydrocarbon fuels is the potential for fuel thermal stability and material compatibility problems to occur under the high-pressure, high-temperature conditions required for regenerative fuel cooling of the engine combustion chamber and nozzle. Decreased heat transfer due to carbon deposits forming on wetted fuel components, corrosion of materials common in engine construction (copper based alloys), and corrosion induced pressure drop increases have all been observed in laboratory tests simulating rocket engine cooling channels. To mitigate these risks, the knowledge of how these fuels behave in high temperature environments must be obtained. Currently, due to the complexity of the physical and chemical process occurring, the only way to accomplish this is empirically. Heated tube testing is a well-established method of experimentally determining the thermal stability and heat transfer characteristics of hydrocarbon fuels. The popularity of this method stems from the low cost incurred in testing when compared to hot fire engine tests, the ability to have greater control over experimental conditions, and the accessibility of the test section, facilitating easy instrumentation. These benefits make heated tube testing the best alternative to hot fire engine testing for thermal stability and heat transfer research. This investigation used the Heated Tube Facility at the NASA Glenn Research Center to perform a thermal stability and heat transfer characterization of RP-1 in an environment simulating that of a high chamber pressure, regenerative cooled rocket engine. The first step in the research was to investigate the carbon deposition process of previous heated tube experiments by performing scanning electron microscopic analysis in conjunction with energy dispersive spectroscopy on the tube sections. This analysis gave insight into the carbon deposition process and the effect that test conditions played in the formation of deleterious coke. Furthermore, several different formations were observed and noted. One other crucial finding of this investigation was that in sulfur containing hydrocarbon fuels, the interaction of the sulfur components with copper based wall materials presented a significant corrosion problem. This problem in many cases was more life limiting than those posed by the carbon deposition process. The results of this microscopic analysis was detailed and presented at the December 2003 JANNAF Air-Breathing Propulsion Meeting as a Materials Compatibility and Thermal Stability Analysis of common Hydrocarbon Fuels (reference 1).

Detailed performance analysis of the A.A.D. - concept B

NASA Technical Reports Server (NTRS)

Sekar, R.; Tozzi, L.

1983-01-01

New concepts for engine performance improvement are seen through the adoption of heat regeneration techniques; advanced methods to enhance the combustion; and higher efficiency air handling machinery, such as the positive displacement helical screw expander and compressor. Each of these concepts plays a particular role in engine performance improvement. First regeneration has a great potential for achieving higher engine thermal efficiency through the recovery of waste energy. Although the concept itself is not new (this technique is used in the gas turbine), the application to reciprocating internal combustion engines is quite unusual and presents conceptual difficulties. The second important area is better control of the combustion process in terms of heat transfer characteristics, combustion products, and heat release rate. The third area for performance improvement is in the adoption of high efficiency air handling machinery. In particular, positive displacement helical expander and compressor exhibit an extremely high efficiency over a wide range of operating conditions.

Gas engine heat pump cycle analysis. Volume 1: Model description and generic analysis

NASA Astrophysics Data System (ADS)

Fischer, R. D.

1986-10-01

The task has prepared performance and cost information to assist in evaluating the selection of high voltage alternating current components, values for component design variables, and system configurations and operating strategy. A steady-state computer model for performance simulation of engine-driven and electrically driven heat pumps was prepared and effectively used for parametric and seasonal performance analyses. Parametric analysis showed the effect of variables associated with design of recuperators, brine coils, domestic hot water heat exchanger, compressor size, engine efficiency, insulation on exhaust and brine piping. Seasonal performance data were prepared for residential and commercial units in six cities with system configurations closely related to existing or contemplated hardware of the five GRI engine contractors. Similar data were prepared for an advanced variable-speed electric unit for comparison purposes. The effect of domestic hot water production on operating costs was determined. Four fan-operating strategies and two brine loop configurations were explored.

Ceramic Technology Project semiannual progress report, April 1992--September 1992

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, D.R.

1993-07-01

This project was developed to meet the ceramic technology requirements of the DOE Office of Transportation Systems` automotive technology programs. Significant progress in fabricating ceramic components for DOE, NASA, and DOE advanced heat engine programs show that operation of ceramic parts in high-temperature engines is feasible; however, addition research is needed in materials and processing, design, and data base and life prediction before industry will have a sufficient technology base for producing reliable cost-effective ceramic engine components commercially. A 5-yr project plan was developed, with focus on structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments,more » and ceramic coatings for thermal barrier and wear applications in these engines.« less

Use of cooling air heat exchangers as replacements for hot section strategic materials

NASA Technical Reports Server (NTRS)

Gauntner, J. W.

1983-01-01

Because of financial and political constraints, strategic aerospace materials required for the hot section of future engines might be in short supply. As an alternative to these strategic materials, this study examines the use of a cooling air heat exchanger in combination with less advanced hot section materials. Cycle calculations are presented for future turbofan systems with overall pressure ratios to 65, bypass ratios near 13, and combustor exit temperatures to 3260 R. These calculations quantify the effect on TSFC of using a decreased materials technology in a turbofan system. The calculations show that the cooling air heat exchanger enables the feasibility of these engines.

Development of Engineering Data on Advanced Composite Materials

DTIC Science & Technology

1977-09-01

O AFML-TR-77-15 1 ,* • DEVELOPMENT OF ENGINEERING DATA ON ’ ADVANCED COMPOSITE MATERIALS UNIVERSITY OF DAYTON RESEARCH INSTITUTE I - UNIVERSITY OF DA...SUMMARIZED COMPOSITE DATA 47 4.1 SP313 48 4.2 AS/3004 86 4.3 AS/4397 125 4.4 T300/F178 163 4.5 COMPARATIVE ENVIRONMENTAL BEHAVIOR 194 5 CONCLUSIONS 197...AGED INTERLAKINAR SHEAR DATA 452 vi -. -| |b. ~ - LIST OF ILLUSTRATIONS FIGURE PACE 1 Typical Cross Sections of Fabricated Composites 12 2 Heat-Up

Energy and cost savings results for advanced technology systems from the Cogeneration Technology Alternatives Study /CTAS/

NASA Technical Reports Server (NTRS)

Sagerman, G. D.; Barna, G. J.; Burns, R. K.

1979-01-01

The Cogeneration Technology Alternatives Study (CTAS), a program undertaken to identify the most attractive advanced energy conversion systems for industrial cogeneration applications in the 1985-2000 time period, is described, and preliminary results are presented. Two cogeneration options are included in the analysis: a topping application, in which fuel is input to the energy conversion system which generates electricity and waste heat from the conversion system is used to provide heat to the process, and a bottoming application, in which fuel is burned to provide high temperature process heat and waste heat from the process is used as thermal input to the energy conversion system which generates energy. Steam turbines, open and closed cycle gas turbines, combined cycles, diesel engines, Stirling engines, phosphoric acid and molten carbonate fuel cells and thermionics are examined. Expected plant level energy savings, annual energy cost savings, and other results of the economic analysis are given, and the sensitivity of these results to the assumptions concerning fuel prices, price of purchased electricity and the potential effects of regional energy use characteristics is discussed.

Software For Three-Dimensional Stress And Thermal Analyses

NASA Technical Reports Server (NTRS)

Banerjee, P. K.; Wilson, R. B.; Hopkins, D. A.

1994-01-01

BEST3D is advanced engineering software system for three-dimensional thermal and stress analyses, particularly of components of hot sections of gas-turbine engines. Utilizes boundary element method, offering, in many situations, more accuracy, efficiency, and ease of use than finite element method. Performs engineering analyses of following types: elastic, heat transfer, plastic, forced vibration, free vibration, and transient elastodynamic. Written in FORTRAN 77.

Comparison of Stirling engines for use with a 25-kW disk-electric conversion system

NASA Technical Reports Server (NTRS)

Shaltens, Richard K.

1987-01-01

Heat engines were evaluated for terrestrial solar heat receivers. The Stirling Engine was identified as one of the most promising engines for terrestrial applications. The potential to meet the Department of Energy (DOE) goals for performance and cost can be met by the free-piston Stirling engine. NASA Lewis is providing technical management for an Advanced Stirling Conversion System (ASCS) through a cooperative interagency agreement with DOE. Parallel contracts were awarded for conceptual designs of an ASCS. Each design will feature a free-piston Stirling engine, a liquid-metal heat pipe receiver, and a means to provide about 25 kW of electric power to a utility grid while meeting long-term performance and goals. The Mechanical Technology, Ins. (MTI) design incorporates a linear alternator to directly convert the solar energy to electricity while the Stirling Technology Company (STC) generates electrical power indirectly by using a hydraulic output to a ground-bases hydraulic pump/motor coupled to a rotating alternator. Both designs use technology which can reasonably be expected to be available in the 1980's. The ASCS designs using a free-piston Stirling engine, a heat transport system, a receiver, and the methods of providing electricity to the utility grid will be discussed.

Thermal and Environmental Barrier Coatings for Advanced Turbine Engine Applications

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Miller, Robert A.

2005-01-01

Ceramic thermal and environmental barrier coatings (T/EBCs) will play a crucial role in advanced gas turbine engine systems because of their ability to significantly increase engine operating temperatures and reduce cooling requirements, thus help achieve engine low emission and high efficiency goals. Advanced T/EBCs are being developed for the low emission SiC/SiC ceramic matrix composite (CMC) combustor applications by extending the CMC liner and vane temperature capability to 1650 C (3000 F) in oxidizing and water vapor containing combustion environments. Low conductivity thermal barrier coatings (TBCs) are also being developed for metallic turbine airfoil and combustor applications, providing the component temperature capability up to 1650 C (3000 F). In this paper, ceramic coating development considerations and requirements for both the ceramic and metallic components will be described for engine high temperature and high-heat-flux applications. The underlying coating failure mechanisms and life prediction approaches will be discussed based on the simulated engine tests and fracture mechanics modeling results.

Comparison of advanced thermal and electrical storage for parabolic dish solar thermal power systems

NASA Astrophysics Data System (ADS)

Fujita, T.; Birur, G. C.; Schredder, J. M.; Bowyer, J. M.; Awaya, H. I.

Parabolic dish solar concentrator cluster concepts are explored, with attention given to thermal storage systems coupled to Stirling and Brayton cycle power conversion devices. Sensible heat storage involving molten salt (NaOH), liquid sodium, and solid cordierite bricks are considered for 1500 F thermal storage systems. Latent heat storage with NaF-MgF2 phase change materials are explored in terms of passive, active, and direct contact designs. Comparisons are made of the effectiveness of thermal storage relative to redox, Na-S, Zn-Cl, and Zn-Br battery storage systems. Molten lead trickling down through a phase change eutectic, the NaF-MgF2, formed the direct contact system. Heat transport in all systems is effected through Inconel pipes. Using a cost goal of 120-150 mills/kWh as the controlling parameter, sensible heat systems with molten salts transport with either Stirling or Brayton engines, or latent heat systems with Stirling engines, and latent heat-Brayton engine with direct contact were favored in the analyses. Battery storage systems, however, offered the most flexibility of applications.

Comparison of advanced thermal and electrical storage for parabolic dish solar thermal power systems

NASA Technical Reports Server (NTRS)

Fujita, T.; Birur, G. C.; Schredder, J. M.; Bowyer, J. M.; Awaya, H. I.

1982-01-01

Parabolic dish solar concentrator cluster concepts are explored, with attention given to thermal storage systems coupled to Stirling and Brayton cycle power conversion devices. Sensible heat storage involving molten salt (NaOH), liquid sodium, and solid cordierite bricks are considered for 1500 F thermal storage systems. Latent heat storage with NaF-MgF2 phase change materials are explored in terms of passive, active, and direct contact designs. Comparisons are made of the effectiveness of thermal storage relative to redox, Na-S, Zn-Cl, and Zn-Br battery storage systems. Molten lead trickling down through a phase change eutectic, the NaF-MgF2, formed the direct contact system. Heat transport in all systems is effected through Inconel pipes. Using a cost goal of 120-150 mills/kWh as the controlling parameter, sensible heat systems with molten salts transport with either Stirling or Brayton engines, or latent heat systems with Stirling engines, and latent heat-Brayton engine with direct contact were favored in the analyses. Battery storage systems, however, offered the most flexibility of applications.

Advanced solar receivers for space power

NASA Technical Reports Server (NTRS)

Strumpf, H. J.; Coombs, M. G.; Lacy, D. E.

1988-01-01

A study has been conducted to generate and evaluate advanced solar heat receiver concepts suitable for orbital application with Brayton and Stirling engine cycles in the 7-kW size range. The generated receiver designs have thermal storage capability and, when implemented, will be lighter, smaller, and/or more efficient than baseline systems such as the configuration used for the Brayton solar receiver under development by Garrett AiResearch for the NASA Space Station. In addition to the baseline designs, four other receiver concepts were designed and evaluated with respect to Brayton and Stirling engines. These concepts include a higher temperature version of the baseline receiver, a packed bed receiver, a plate-fin receiver, and a heat pipe receiver. The thermal storage for all designs is provided by the melting and freezing of a salt.

40 CFR 86.230-11 - Test sequence: general requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... vehicle interior climate control system shall be operated with the interior heating system on and the air... changes (e.g., engine-off logic, idle speed operation, spark advance changes) and engine control features...) Prior to the first acceleration of the test at T=20 seconds the climate control settings shall be set as...

40 CFR 86.230-11 - Test sequence: general requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... vehicle interior climate control system shall be operated with the interior heating system on and the air... changes (e.g., engine-off logic, idle speed operation, spark advance changes) and engine control features...) Prior to the first acceleration of the test at T=20 seconds the climate control settings shall be set as...

40 CFR 86.230-11 - Test sequence: general requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... vehicle interior climate control system shall be operated with the interior heating system on and the air... changes (e.g., engine-off logic, idle speed operation, spark advance changes) and engine control features...) Prior to the first acceleration of the test at T=20 seconds the climate control settings shall be set as...

40 CFR 86.230-11 - Test sequence: general requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... vehicle interior climate control system shall be operated with the interior heating system on and the air... changes (e.g., engine-off logic, idle speed operation, spark advance changes) and engine control features...) Prior to the first acceleration of the test at T=20 seconds the climate control settings shall be set as...

An overview of the Penn State Propulsion Engineering Research Center

NASA Technical Reports Server (NTRS)

Merkle, Charles L.

1991-01-01

An overview of the Penn State Propulsion Engineering Research Center is presented. The following subject areas are covered: research objectives and long term perspective of the Center; current status and operational philosophy; and brief description of Center projects (combustion, fluid mechanics and heat transfer, materials compatibility, turbomachinery, and advanced propulsion concepts).

Identifying student difficulties with entropy, heat engines, and the Carnot cycle

NASA Astrophysics Data System (ADS)

Smith, Trevor I.; Christensen, Warren M.; Mountcastle, Donald B.; Thompson, John R.

2015-12-01

[This paper is part of the Focused Collection on Upper Division Physics Courses.] We report on several specific student difficulties regarding the second law of thermodynamics in the context of heat engines within upper-division undergraduate thermal physics courses. Data come from ungraded written surveys, graded homework assignments, and videotaped classroom observations of tutorial activities. Written data show that students in these courses do not clearly articulate the connection between the Carnot cycle and the second law after lecture instruction. This result is consistent both within and across student populations. Observation data provide evidence for myriad difficulties related to entropy and heat engines, including students' struggles in reasoning about situations that are physically impossible and failures to differentiate between differential and net changes of state properties of a system. Results herein may be seen as the application of previously documented difficulties in the context of heat engines, but others are novel and emphasize the subtle and complex nature of cyclic processes and heat engines, which are central to the teaching and learning of thermodynamics and its applications. Moreover, the sophistication of these difficulties is indicative of the more advanced thinking required of students at the upper division, whose developing knowledge and understanding give rise to questions and struggles that are inaccessible to novices.

Orbit transfer rocket engine technology program: Oxygen materials compatibility testing

NASA Technical Reports Server (NTRS)

Schoenman, Leonard

1989-01-01

Particle impact and frictional heating tests of metals in high pressure oxygen, are conducted in support of the design of an advanced rocket engine oxygen turbopump. Materials having a wide range of thermodynamic properties including heat of combustion and thermal diffusivity were compared in their resistance to ignition and sustained burning. Copper, nickel and their alloys were found superior to iron based and stainless steel alloys. Some materials became more difficult to ignite as oxygen pressure was increased from 7 to 21 MPa (1000 to 3000 psia).

Advances in cryogenic engineering. Volume 33 - Proceedings of the Cryogenic Engineering Conference, Saint Charles, IL, June 14-18, 1987

NASA Technical Reports Server (NTRS)

Fast, R. W. (Editor)

1988-01-01

Papers are presented on superconductivity applications including magnets, electronics, rectifiers, magnet stability, coil protection, and cryogenic techniques. Also considered are insulation, heat transfer to liquid helium and nitrogen, heat and mass transfer in He II, superfluid pumps, and refrigeration for superconducting systems. Other topics include cold compressors, refrigeration and liquefaction, magnetic refrigeration, and refrigeration for space applications. Papers are also presented on cryogenic applications, commercial cryogenic plants, the properties of cryogenic fluids, and cryogenic instrumentation and data acquisition.

Advanced propulsion system for hybrid vehicles

NASA Technical Reports Server (NTRS)

Norrup, L. V.; Lintz, A. T.

1980-01-01

A number of hybrid propulsion systems were evaluated for application in several different vehicle sizes. A conceptual design was prepared for the most promising configuration. Various system configurations were parametrically evaluated and compared, design tradeoffs performed, and a conceptual design produced. Fifteen vehicle/propulsion systems concepts were parametrically evaluated to select two systems and one vehicle for detailed design tradeoff studies. A single hybrid propulsion system concept and vehicle (five passenger family sedan)were selected for optimization based on the results of the tradeoff studies. The final propulsion system consists of a 65 kW spark-ignition heat engine, a mechanical continuously variable traction transmission, a 20 kW permanent magnet axial-gap traction motor, a variable frequency inverter, a 386 kg lead-acid improved state-of-the-art battery, and a transaxle. The system was configured with a parallel power path between the heat engine and battery. It has two automatic operational modes: electric mode and heat engine mode. Power is always shared between the heat engine and battery during acceleration periods. In both modes, regenerative braking energy is absorbed by the battery.

Numerical analysis of the hot-gas-side and coolant-side heat transfer in liquid rocket engine combustors

NASA Technical Reports Server (NTRS)

Wang, Ten-See; Van, Luong

1992-01-01

The objective of this paper are to develop a multidisciplinary computational methodology to predict the hot-gas-side and coolant-side heat transfer and to use it in parametric studies to recommend optimized design of the coolant channels for a regeneratively cooled liquid rocket engine combustor. An integrated numerical model which incorporates CFD for the hot-gas thermal environment, and thermal analysis for the liner and coolant channels, was developed. This integrated CFD/thermal model was validated by comparing predicted heat fluxes with those of hot-firing test and industrial design methods for a 40 k calorimeter thrust chamber and the Space Shuttle Main Engine Main Combustion Chamber. Parametric studies were performed for the Advanced Main Combustion Chamber to find a strategy for a proposed combustion chamber coolant channel design.

Status and summary of laser energy conversion. [for space power transmission systems

NASA Technical Reports Server (NTRS)

Lee, G.

1978-01-01

This paper presents a survey of the status of laser energy converters. Since the inception of these devices in the early 1970's, significant advances have been made in understanding the basic conversion processes. Numerous theoretical and experimental studies have indicated that laser energy can be converted at wavelengths from the ultraviolet to the far-infrared. These converters can be classified into five general categories: photovoltaics, heat engines, thermoelectronic, optical diode, and photochemical. The conversion can be directly into electricity (such as the photovoltaic, thermoelectronic, and optical diode) or it can go through an intermediate stage of conversion to mechanical energy, as in the heat engines. The photochemical converters result in storable energy such as hydrogen. Projected conversion efficiencies range from about 30% for the photochemical to nearly 75% for the heat engines.

GRC-2015-C-00903

NASA Image and Video Library

2011-03-15

NASA (Zin Technologies) engineer prepares Advanced Colloid Experiment Heated-2 samples that will be analyzed aboard the International Space Station using the zero-gravity Light Microscopy Module, LMM in the Fluids Integrated Rack, FIR

Advanced Gas Turbine (AGT) powertrain system development for automotive applications

NASA Technical Reports Server (NTRS)

1981-01-01

Preliminary layouts were made for the exhaust system, air induction system, and battery installation. Points of interference were identified and resolved by altering either the vehicle or engine designs. An engine general arrangement evolved to meet the vehicle engine compartment constraints while minimizing the duct pressure losses and the heat rejection. A power transfer system (between gasifier and power turbines) was developed to maintain nearly constant temperatures throughout the entire range of engine operation. An advanced four speed automatic transmission was selected to be used with the engine. Performance calculations show improvements in component efficiencies and an increase in fuel economy. A single stage centrifugal compressor design was completed and released for procurement. Gasifier turbine, power turbine, combustor, generator, secondary systems, materials, controls, and transmission development are reported.

Advanced supersonic propulsion study. [with emphasis on noise level reduction

NASA Technical Reports Server (NTRS)

Sabatella, J. A. (Editor)

1974-01-01

A study was conducted to determine the promising propulsion systems for advanced supersonic transport application, and to identify the critical propulsion technology requirements. It is shown that noise constraints have a major effect on the selection of the various engine types and cycle parameters. Several promising advanced propulsion systems were identified which show the potential of achieving lower levels of sideline jet noise than the first generation supersonic transport systems. The non-afterburning turbojet engine, utilizing a very high level of jet suppression, shows the potential to achieve FAR 36 noise level. The duct-heating turbofan with a low level of jet suppression is the most attractive engine for noise levels from FAR 36 to FAR 36 minus 5 EPNdb, and some series/parallel variable cycle engines show the potential of achieving noise levels down to FAR 36 minus 10 EPNdb with moderate additional penalty. The study also shows that an advanced supersonic commercial transport would benefit appreciably from advanced propulsion technology. The critical propulsion technology needed for a viable supersonic propulsion system, and the required specific propulsion technology programs are outlined.

Advanced Environmental Barrier Coating Development for SiC-SiC Ceramic Matrix Composite Components

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna; Kiser, Doug; Wiesner, Valerie L.

2016-01-01

This presentation reviews the NASA advanced environmental barrier coating (EBC) system development for SiCSiC Ceramic Matrix Composite (CMC) components for next generation turbine engines. The emphasis has been placed on the current design challenges of the 2700F environmental barrier coatings; coating processing and integration with SiCSiC CMCs and component systems; and performance evaluation and demonstration of EBC-CMC systems. This presentation also highlights the EBC-CMC system temperature capability and durability improvements through advanced compositions and architecture designs, as shown in recent simulated engine high heat flux, combustion environment, in conjunction with mechanical creep and fatigue loading testing conditions.

Use of cooling air heat exchangers as replacements for hot section strategic materials

NASA Technical Reports Server (NTRS)

Gauntner, J. W.

1983-01-01

Because of financial and political constraints, strategic aerospace materials required for the hot section of future engines might be in short supply. As an alternative to these strategic materials, this study examines the use of a cooling air heat exchanger in combination with less advanced hot section materials. Cycle calculations are presented for future turbofan systems with overall pressure ratios to 65, bypass ratios near 13, and combustor exit temperatures to 3260 R. These calculations quantify the effect on TSFC of using a decreased materials technology in a turbofan system. The calculations show that the cooling air heat exchanger enables the feasibility of these engines. Previously announced in STAR as N83-34946

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1994-01-01

Reports technical effort by AlliedSignal Engines in sixth year of DOE/NASA funded project. Topics include: gas turbine engine design modifications of production APU to incorporate ceramic components; fabrication and processing of silicon nitride blades and nozzles; component and engine testing; and refinement and development of critical ceramics technologies, including: hot corrosion testing and environmental life predictive model; advanced NDE methods for internal flaws in ceramic components; and improved carbon pulverization modeling during impact. ATTAP project is oriented toward developing high-risk technology of ceramic structural component design and fabrication to carry forward to commercial production by 'bridging the gap' between structural ceramics in the laboratory and near-term commercial heat engine application. Current ATTAP project goal is to support accelerated commercialization of advanced, high-temperature engines for hybrid vehicles and other applications. Project objectives are to provide essential and substantial early field experience demonstrating ceramic component reliability and durability in modified, available, gas turbine engine applications; and to scale-up and improve manufacturing processes of ceramic turbine engine components and demonstrate application of these processes in the production environment.

Advanced Environmental Barrier Coatings Development for Si-Based Ceramics

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Choi, R. Sung; Robinson, Raymond C.; Lee, Kang N.; Bhatt, Ramakrishna T.; Miller, Robert A.

2005-01-01

Advanced environmental barrier coating concepts based on multi-component HfO2 (ZrO2) and modified mullite systems are developed for monolithic Si3N4 and SiC/SiC ceramic matrix composite (CMC) applications. Comprehensive testing approaches were established using the water vapor cyclic furnace, high pressure burner rig and laser heat flux steam rig to evaluate the coating water vapor stability, cyclic durability, radiation and erosion resistance under simulated engine environments. Test results demonstrated the feasibility and durability of the environmental barrier coating systems for 2700 to 3000 F monolithic Si3N4 and SiC/SiC CMC component applications. The high-temperature-capable environmental barrier coating systems are being further developed and optimized in collaboration with engine companies for advanced turbine engine applications.

Life cycle cost assessment of future low heat rejection engines

NASA Technical Reports Server (NTRS)

Petersen, D. R.

1986-01-01

The Adiabatic Diesel Engine Component Development (ADECD) represents a project which has the objective to accelerate the development of highway truck engines with advanced technology aimed at reduced fuel consumption. The project comprises three steps, including the synthesis of a number of engine candidate designs, the coupling of each with a number of systems for utilizing exhaust gas energy, and the evaluation of each combination in terms of desirability. Particular attention is given to the employed evaluation method and the development of this method. The objective of Life Cycle Cost (LCC) evaluation in the ADECD program was to select the best from among 42 different low heat rejection engine (LHRE)/exhaust energy recovery system configurations. The LCC model is discussed along with a maintenance cost model, the evaluation strategy, the selection of parameter ranges, and a full factorial analysis.

Performance and Reliability of Exhaust Gas Waste Heat Recovery Units

DTIC Science & Technology

2014-09-01

transfer in an annulus with an externally enhanced inner tube. International Journal of Heat and Fluid Flow, 14(1), 54‒63. Akpinar, E. K. (2006...from http://www.energy-tech.com/article.cfm?id=17567 Masliyah, J., & Nandakumar, K. (1976). Heat transfer in internally finned tubes. Journal of...exchanger by using turbulator. International Journal of Engineering Science & Advanced Technology, 2(4), 881‒885. Patankar, S. V. (1980). The

Design and Performance Optimizations of Advanced Erosion-Resistant Low Conductivity Thermal Barrier Coatings for Rotorcraft Engines

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.; Kuczmarski, Maria A.

2012-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future rotorcraft engine higher fuel efficiency and lower emission goals. For thermal barrier coatings designed for rotorcraft turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability, because the rotorcraft are often operated in the most severe sand erosive environments. Advanced low thermal conductivity and erosion-resistant thermal barrier coatings are being developed, with the current emphasis being placed on thermal barrier coating toughness improvements using multicomponent alloying and processing optimization approaches. The performance of the advanced thermal barrier coatings has been evaluated in a high temperature erosion burner rig and a laser heat-flux rig to simulate engine erosion and thermal gradient environments. The results have shown that the coating composition and architecture optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic oxidation durability

NASA Propulsion Engineering Research Center, Volume 2

NASA Technical Reports Server (NTRS)

1994-01-01

This is the second volume in the 1994 annual report for the NASA Propulsion Engineering Research Center's Sixth Annual Symposium. This conference covered: (1) Combustors and Nozzles; (2) Turbomachinery Aero- and Hydro-dynamics; (3) On-board Propulsion systems; (4) Advanced Propulsion Applications; (5) Vaporization and Combustion; (6) Heat Transfer and Fluid Mechanics; and (7) Atomization and Sprays.

Calcium-magnesium Aluminosilicate (CMAS) Interactions with Advanced Environmental Barrier Coating Material

NASA Technical Reports Server (NTRS)

Wiesner, Valerie L.; Bansal, Narottam P.

2015-01-01

Particulates, like sand and volcanic ash, threaten the development of robust environmental barrier coatings (EBCs) that protect next-generation silicon-based ceramic matrix composite (CMC) turbine engine components from harsh combustion environments during service. The siliceous particulates transform into molten glassy deposits of calcium-magnesium aluminosilicate (CMAS) when ingested by an aircraft engine operating at temperatures above 1200C. In this study, a sample of desert sand was melted into CMAS glass to evaluate high-temperature interactions between the sand glass and an advanced EBC material. Desert sand glass was added to the surface of hot-pressed EBC substrates, which were then heated in air at temperatures ranging from 1200C to 1500C. Scanning electron microscopy and X-ray energy-dispersive spectroscopy were used to evaluate microstructure and phase compositions of specimens and the CMASEBC interface after heat treatments.

Improved silicon carbide for advanced heat engines

NASA Technical Reports Server (NTRS)

Whalen, Thomas J.

1987-01-01

This is the second annual technical report entitled, Improved Silicon Carbide for Advanced Heat Engines, and includes work performed during the period February 16, 1986 to February 15, 1987. The program is conducted for NASA under contract NAS3-24384. The objective is the development of high strength, high reliability silicon carbide parts with complex shapes suitable for use in advanced heat engines. The fabrication methods used are to be adaptable for mass production of such parts on an economically sound basis. Injection molding is the forming method selected. This objective is to be accomplished in a two-phase program: (1) to achieve a 20 percent improvement in strength and a 100 percent increase in Weibull modulus of the baseline material; and (2) to produce a complex shaped part, a gas turbine rotor, for example, with the improved mechanical properties attained in the first phase. Eight tasks are included in the first phase covering the characterization of the properties of a baseline material, the improvement of those properties and the fabrication of complex shaped parts. Activities during the first contract year concentrated on two of these areas: fabrication and characterization of the baseline material (Task 1) and improvement of material and processes (Task 7). Activities during the second contract year included an MOR bar matrix study to improve mechanical properties (Task 2), materials and process improvements (Task 7), and a Ford-funded task to mold a turbocharger rotor with an improved material (Task 8).

Improved silicon carbide for advanced heat engines

NASA Technical Reports Server (NTRS)

Whalen, Thomas J.

1988-01-01

This is the third annual technical report for the program entitled, Improved Silicon Carbide for Advanced Heat Engines, for the period February 16, 1987 to February 15, 1988. The objective of the original program was the development of high strength, high reliability silicon carbide parts with complex shapes suitable for use in advanced heat engines. Injection molding is the forming method selected for the program because it is capable of forming complex parts adaptable for mass production on an economically sound basis. The goals of the revised program are to reach a Weibull characteristic strength of 550 MPa (80 ksi) and a Weibull modulus of 16 for bars tested in 4-point loading. Two tasks are discussed: Task 1 which involves materials and process improvements, and Task 2 which is a MOR bar matrix to improve strength and reliability. Many statistically designed experiments were completed under task 1 which improved the composition of the batches, the mixing of the powders, the sinter and anneal cycles. The best results were obtained by an attritor mixing process which yielded strengths in excess of 550 MPa (80 ksi) and an individual Weibull modulus of 16.8 for a 9-sample group. Strengths measured at 1200 and 1400 C were equal to the room temperature strength. Annealing of machined test bars significantly improved the strength. Molding yields were measured and flaw distributions were observed to follow a Poisson process. The second iteration of the Task 2 matrix experiment is described.

Nanoscale phase engineering of thermal transport with a Josephson heat modulator.

PubMed

Fornieri, Antonio; Blanc, Christophe; Bosisio, Riccardo; D'Ambrosio, Sophie; Giazotto, Francesco

2016-03-01

Macroscopic quantum phase coherence has one of its pivotal expressions in the Josephson effect, which manifests itself both in charge and energy transport. The ability to master the amount of heat transferred through two tunnel-coupled superconductors by tuning their phase difference is the core of coherent caloritronics, and is expected to be a key tool in a number of nanoscience fields, including solid-state cooling, thermal isolation, radiation detection, quantum information and thermal logic. Here, we show the realization of the first balanced Josephson heat modulator designed to offer full control at the nanoscale over the phase-coherent component of thermal currents. Our device provides magnetic-flux-dependent temperature modulations up to 40 mK in amplitude with a maximum of the flux-to-temperature transfer coefficient reaching 200 mK per flux quantum at a bath temperature of 25 mK. Foremost, it demonstrates the exact correspondence in the phase engineering of charge and heat currents, breaking ground for advanced caloritronic nanodevices such as thermal splitters, heat pumps and time-dependent electronic engines.

Nanoscale phase engineering of thermal transport with a Josephson heat modulator

NASA Astrophysics Data System (ADS)

Fornieri, Antonio; Blanc, Christophe; Bosisio, Riccardo; D'Ambrosio, Sophie; Giazotto, Francesco

2016-03-01

Macroscopic quantum phase coherence has one of its pivotal expressions in the Josephson effect, which manifests itself both in charge and energy transport. The ability to master the amount of heat transferred through two tunnel-coupled superconductors by tuning their phase difference is the core of coherent caloritronics, and is expected to be a key tool in a number of nanoscience fields, including solid-state cooling, thermal isolation, radiation detection, quantum information and thermal logic. Here, we show the realization of the first balanced Josephson heat modulator designed to offer full control at the nanoscale over the phase-coherent component of thermal currents. Our device provides magnetic-flux-dependent temperature modulations up to 40 mK in amplitude with a maximum of the flux-to-temperature transfer coefficient reaching 200 mK per flux quantum at a bath temperature of 25 mK. Foremost, it demonstrates the exact correspondence in the phase engineering of charge and heat currents, breaking ground for advanced caloritronic nanodevices such as thermal splitters, heat pumps and time-dependent electronic engines.

Thermal Characterization of Nanostructures and Advanced Engineered Materials

NASA Astrophysics Data System (ADS)

Goyal, Vivek Kumar

Continuous downscaling of Si complementary metal-oxide semiconductor (CMOS) technology and progress in high-power electronics demand more efficient heat removal techniques to handle the increasing power density and rising temperature of hot spots. For this reason, it is important to investigate thermal properties of materials at nanometer scale and identify materials with the extremely large or extremely low thermal conductivity for applications as heat spreaders or heat insulators in the next generation of integrated circuits. The thin films used in microelectronic and photonic devices need to have high thermal conductivity in order to transfer the dissipated power to heat sinks more effectively. On the other hand, thermoelectric devices call for materials or structures with low thermal conductivity because the performance of thermoelectric devices is determined by the figure of merit Z=S2sigma/K, where S is the Seebeck coefficient, K and sigma are the thermal and electrical conductivity, respectively. Nanostructured superlattices can have drastically reduced thermal conductivity as compared to their bulk counterparts making them promising candidates for high-efficiency thermoelectric materials. Other applications calling for thin films with low thermal conductivity value are high-temperature coatings for engines. Thus, materials with both high thermal conductivity and low thermal conductivity are technologically important. The increasing temperature of the hot spots in state-of-the-art chips stimulates the search for innovative methods for heat removal. One promising approach is to incorporate materials, which have high thermal conductivity into the chip design. Two suitable candidates for such applications are diamond and graphene. Another approach is to integrate the high-efficiency thermoelectric elements for on-spot cooling. In addition, there is strong motivation for improved thermal interface materials (TIMs) for heat transfer from the heat-generating chip to heat-sinking units. This dissertation presents results of the experimental investigation and theoretical interpretation of thermal transport in the advanced engineered materials, which include thin films for thermal management of nanoscale devices, nanostructured superlattices as promising candidates for high-efficiency thermoelectric materials, and improved TIMs with graphene and metal particles as fillers providing enhanced thermal conductivity. The advanced engineered materials studied include chemical vapor deposition (CVD) grown ultrananocrystalline diamond (UNCD) and microcrystalline diamond (MCD) films on Si substrates, directly integrated nanocrystalline diamond (NCD) films on GaN, free-standing polycrystalline graphene (PCG) films, graphene oxide (GOx) films, and "pseudo-superlattices" of the mechanically exfoliated Bi2Te3 topological insulator films, and thermal interface materials (TIMs) with graphene fillers.

Ground Vehicle Power and Mobility (GVPM) Powertrain Overview

DTIC Science & Technology

2011-08-11

efficient on-board electrical power generation • Improved Fuel Efficiency • Thermoelectric Waste Heat Recovery • Advanced Engine Cycle Demo...Thermal Management • Militarized Power train Control Module and strategies devices for military vehicle transmissions FY11 FY12 FY13...Transmission): - Medium Combat Application (20-40 tons) - Medium Tactical Application (15-30 tons) Thermoelectric Waste Heat Recovery Energy Analysis

Experimental assessment of advanced Stirling component concepts

NASA Technical Reports Server (NTRS)

Ziph, B.

1985-01-01

The results of an experimental assessment of some advanced Stirling engine component concepts are presented. High performance piston rings, reciprocating oil scrapers and heat pipes with getters and with mechanical couplings were tested. The tests yielded the following results: (1) Bonded, split, pumping piston rings, in preliminary testing, proved a promising concept, exhibiting low leakage and friction losses. Solid piston rings proved impractical in view of their sensitivity to the operating temperature; (2) A babbit oil scraper in a compliant housing performed well in atmospheric endurance testing. In pressurized tests the scraper did not perform well as a containment seal. The latter tests suggest modifications which may adapt Ti successfully to that application; and (3) Heat pipe endurance tests indicated the adequacy of simple, inexpensive fabrication and filling procedures. Getters were provided to increase the tolerance of the heat pipes to the presence of air and commercially available couplings were demonstrated to be suitable for heat pipe application. In addition to the above tests, the program also included a design effort for a split shaft applicable to a swashplate driven engine with a pressurized crank-case. The design is aimed, and does accomplish, an increase in component life to more than 10,000 hours.

Melt-Infiltration Process For SiC Ceramics And Composites

NASA Technical Reports Server (NTRS)

Behrendt, Donald R.; Singh, Mrityunjay

1994-01-01

Reactive melt infiltration produces silicon carbide-based ceramics and composites faster and more economically than do such processes as chemical vapor infiltration (CVI), reaction sintering, pressureless sintering, hot pressing, and hot isostatic pressing. Process yields dense, strong materials at relatively low cost. Silicon carbide ceramics and composites made by reactive melt infiltration used in combustor liners of jet engines and in nose cones and leading edges of high-speed aircraft and returning spacecraft. In energy industry, materials used in radiant-heater tubes, heat exchangers, heat recuperators, and turbine parts. Materials also well suited to demands of advanced automobile engines.

Turbine blade tip durability analysis

NASA Technical Reports Server (NTRS)

Mcknight, R. L.; Laflen, J. H.; Spamer, G. T.

1981-01-01

An air-cooled turbine blade from an aircraft gas turbine engine chosen for its history of cracking was subjected to advanced analytical and life-prediction techniques. The utility of advanced structural analysis techniques and advanced life-prediction techniques in the life assessment of hot section components are verified. Three dimensional heat transfer and stress analyses were applied to the turbine blade mission cycle and the results were input into advanced life-prediction theories. Shortcut analytical techniques were developed. The proposed life-prediction theories are evaluated.

Microfog lubricant application system for advanced turbine engine components, phase 2. Tasks 3, 4 and 5: Wettability and heat transfer of microfog jets impinging on a heated rotating disc, and evaluation of reclassifying nozzles and a vortex mist generator

NASA Technical Reports Server (NTRS)

Shim, J.; Leonardi, S. J.

1972-01-01

The wettabilities and heat transfer rates of microfog jets (oil-mist nozzle flows) impinging on a heated rotating disc were determined under an inert atmosphere of nitrogen at temperatures ranging from 600 to 800 F. The results are discussed in relation to the various factors involved in the microfog lubricant application systems. Two novel reclassifying nozzles and a vortex mist generator were also studied.

Orbital transfer rocket engine technology program: Soft wear ring seal technology

NASA Technical Reports Server (NTRS)

Lariviere, Brian W.

1992-01-01

Liquid oxygen (LOX) compatibility tests, including autogenous ignition, promoted ignition, LOX impact tests, and friction and wear tests on different PV products were conducted for several polymer materials as verification for the implementation of soft wear ring seals in advanced rocket engine turbopumps. Thermoplastics, polyimide based materials, and polyimide-imide base materials were compared for oxygen compatibility, specific wear coefficient, wear debris production, and heat dissipation mechanisms. A thermal model was generated that simulated the frictional heating input and calculated the surface temperature and temperature distribution within the seal. The predictions were compared against measured values. Heat loads in the model were varied to better match the test data and determine the difference between the measured and the calculated coefficients of friction.

Advanced Low Conductivity Thermal Barrier Coatings: Performance and Future Directions (Invited paper)

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2008-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. In this presentation, thermal barrier coating development considerations and performance will be emphasized. Advanced thermal barrier coatings have been developed using a multi-component defect clustering approach, and shown to have improved thermal stability and lower conductivity. The coating systems have been demonstrated for high temperature combustor applications. For thermal barrier coatings designed for turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability. Erosion resistant thermal barrier coatings are being developed, with a current emphasis on the toughness improvements using a combined rare earth- and transition metal-oxide doping approach. The performance of the toughened thermal barrier coatings has been evaluated in burner rig and laser heat-flux rig simulated engine erosion and thermal gradient environments. The results have shown that the coating composition optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic durability. The erosion, impact and high heat-flux damage mechanisms of the thermal barrier coatings will also be described.

Advanced Low Conductivity Thermal Barrier Coatings: Performance and Future Directions

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2008-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. In this presentation, thermal barrier coating development considerations and performance will be emphasized. Advanced thermal barrier coatings have been developed using a multi-component defect clustering approach, and shown to have improved thermal stability and lower conductivity. The coating systems have been demonstrated for high temperature combustor applications. For thermal barrier coatings designed for turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability. Erosion resistant thermal barrier coatings are being developed, with a current emphasis on the toughness improvements using a combined rare earth- and transition metal-oxide doping approach. The performance of the toughened thermal barrier coatings has been evaluated in burner rig and laser heat-flux rig simulated engine erosion and thermal gradient environments. The results have shown that the coating composition optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic durability. The erosion, impact and high heat-flux damage mechanisms of the thermal barrier coatings will also be described.

Fuel properties effect on the performance of a small high temperature rise combustor

NASA Technical Reports Server (NTRS)

Acosta, Waldo A.; Beckel, Stephen A.

1989-01-01

The performance of an advanced small high temperature rise combustor was experimentally determined at NASA-Lewis. The combustor was designed to meet the requirements of advanced high temperature, high pressure ratio turboshaft engines. The combustor featured an advanced fuel injector and an advanced segmented liner design. The full size combustor was evaluated at power conditions ranging from idle to maximum power. The effect of broad fuel properties was studied by evaluating the combustor with three different fuels. The fuels used were JP-5, a blend of Diesel Fuel Marine/Home Heating Oil, and a blend of Suntec C/Home Heating Oil. The fuel properties effect on the performance of the combustion in terms of pattern factor, liner temperatures, and exhaust emissions are documented.

Thermal Cyclic Behavior of Thermal and Environmental Barrier Coatings Investigated Under High-Heat-Flux Conditions

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Lee, Kang N.; Miller, Robert A.

2002-01-01

Environmental barrier coatings (EBC's) have been developed to protect silicon-carbide- (SiC) based ceramic components in gas turbine engines from high-temperature environmental attack. With continuously increasing demands for significantly higher engine operating temperature, future EBC systems must be designed for both thermal and environmental protection of the engine components in combustion gases. In particular, the thermal barrier functions of EBC's become a necessity for reducing the engine-component thermal loads and chemical reaction rates, thus maintaining the required mechanical properties and durability of these components. Advances in the development of thermal and environmental barrier coatings (TBC's and EBC's, respectively) will directly impact the successful use of ceramic components in advanced engines. To develop high-performance coating systems, researchers must establish advanced test approaches. In this study, a laser high-heat-flux technique was employed to investigate the thermal cyclic behavior of TBC's and EBC's on SiC-reinforced SiC ceramic matrix composite substrates (SiC/SiC) under high thermal gradient and thermal cycling conditions. Because the laser heat flux test approach can monitor the coating's real-time thermal conductivity variations at high temperature, the coating thermal insulation performance, sintering, and delamination can all be obtained during thermal cycling tests. Plasma-sprayed yttria-stabilized zirconia (ZrO2-8 wt% Y2O3) thermal barrier and barium strontium aluminosilicate-based environmental barrier coatings (BSAS/BSAS+mullite/Si) on SiC/SiC ceramic matrix composites were investigated in this study. These coatings were laser tested in air under thermal gradients (the surface and interface temperatures were approximately 1482 and 1300 C, respectively). Some coating specimens were also subject to alternating furnace cycling (in a 90-percent water vapor environment at 1300 C) and laser thermal gradient cycling tests (in air), to investigate the water vapor effect. All cyclic tests were conducted using a 60-min hot-time temperature.

Heat receivers for solar dynamic space power systems

NASA Astrophysics Data System (ADS)

Perez-Davis, Marla Esther

A review of state-of-the-art technology is presented and discussed for phase change materials. Some of the advanced solar dynamic designs developed as part of the Advanced Heat Receiver Conceptual Design Study performed for LeRC are discussed. The heat receivers are analyzed and several recommendations are proposed, including two new concepts. The first concept evaluated the effect of tube geometries inside the heat receiver. It was found that a triangular configuration would provide better heat transfer to the working fluid, although not necessarily with a reduction in receiver size. A sensible heat receiver considered in this study uses vapor grown graphite fiber-carbon (VGCF/C) composite as the thermal storage media and was designed for a 7 kW Brayton engine. The proposed heat receiver stores the required energy to power the system during eclipse in the VGCF/C composite. The heat receiver analysis was conducted through the Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA) software package. The proposed heat receiver compares well with other latent and advanced sensible heat receivers while avoiding the problems associated with latent heat storage salts and liquid metal heat pipes. The weight and size of the system can be optimized by changes in geometry and technology advances for this new material. In addition to the new concepts, the effect of atomic oxygen on several materials is reviewed. A test was conducted for atomic oxygen attack on boron nitride, which experienced a negligible mass loss when exposed to an atomic oxygen fluence of 5 x 10 exp 21 atoms/sq cm. This material could be used to substitute the graphite aperture plate of the heat receiver.

High-temperature test facility at the NASA Lewis engine components research laboratory

NASA Technical Reports Server (NTRS)

Colantonio, Renato O.

1990-01-01

The high temperature test facility (HTTF) at NASA-Lewis Engine Components Research Laboratory (ECRL) is presently used to evaluate the survivability of aerospace materials and the effectiveness of new sensing instrumentation in a realistic afterburner environment. The HTTF has also been used for advanced heat transfer studies on aerospace components. The research rig uses pressurized air which is heated with two combustors to simulate high temperature flow conditions for test specimens. Maximum airflow is 31 pps. The HTTF is pressure rated for up to 150 psig. Combustors are used to regulate test specimen temperatures up to 2500 F. Generic test sections are available to house test plates and advanced instrumentation. Customized test sections can be fabricated for programs requiring specialized features and functions. The high temperature test facility provides government and industry with a facility for testing aerospace components. Its operation and capabilities are described.

ASME Material Challenges for Advanced Reactor Concepts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piyush Sabharwall; Ali Siahpush

2013-07-01

This study presents the material Challenges associated with Advanced Reactor Concept (ARC) such as the Advanced High Temperature Reactor (AHTR). ACR are the next generation concepts focusing on power production and providing thermal energy for industrial applications. The efficient transfer of energy for industrial applications depends on the ability to incorporate cost-effective heat exchangers between the nuclear heat transport system and industrial process heat transport system. The heat exchanger required for AHTR is subjected to a unique set of conditions that bring with them several design challenges not encountered in standard heat exchangers. The corrosive molten salts, especially at highermore » temperatures, require materials throughout the system to avoid corrosion, and adverse high-temperature effects such as creep. Given the very high steam generator pressure of the supercritical steam cycle, it is anticipated that water tube and molten salt shell steam generators heat exchanger will be used. In this paper, the ASME Section III and the American Society of Mechanical Engineers (ASME) Section VIII requirements (acceptance criteria) are discussed. Also, the ASME material acceptance criteria (ASME Section II, Part D) for high temperature environment are presented. Finally, lack of ASME acceptance criteria for thermal design and analysis are discussed.« less

Preliminary Evaluation of a Turbine/Rotary Combustion Compound Engine for a Subsonic Transport. [fuel consumption and engine tests of turbofan engines

NASA Technical Reports Server (NTRS)

Civinskas, K. C.; Kraft, G. A.

1976-01-01

The fuel consumption of a modern compound engine with that of an advanced high pressure ratio turbofan was compared. The compound engine was derived from a turbofan engine by replacing the combustor with a rotary combustion (RC) engine. A number of boost pressure ratios and compression ratios were examined. Cooling of the RC engine was accomplished by heat exchanging to the fan duct. Performance was estimated with an Otto-cycle for two levels of energy lost to cooling. The effects of added complexity on cost and maintainability were not examined and the comparison was solely in terms of cruise performance and weight. Assuming a 25 percent Otto-cycle cooling loss (representative of current experience), the best compound engine gave a 1.2 percent improvement in cruise. Engine weight increased by 23 percent. For a 10 percent Otto-cycle cooling loss (representing advanced insulation/high temperature materials technology), a compound engine with a boost PR of 10 and a compression ratio of 10 gave an 8.1 percent lower cruise than the reference turbofan.

Conservation and Renewable Energy Program: Bibliography, 1988 edition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vaughan, K.H.

The 831 references covering the period 1980 through Feb. 1988, are arranged under the following: analysis and evaluation, building equipment, building thermal envelope systems and materials, community systems and cogeneration, residential conservation service, retrofit, advanced heat engine ceramics, alternative fuels, microemulsion fuels, industrial chemical heat pumps, materials for waste heat utilization, energy conversion and utilization materials, tribology, emergency energy conservation,inventions, electric energy systems, thermal storage, biofuels production, biotechnology, solar technology, geothermal, and continuous chromatography in multicomponent separations. An author index is included.

Preliminary designs for 25 kWe advanced Stirling conversion systems for dish electric applications

NASA Technical Reports Server (NTRS)

Shaltens, Richard K.; Schreiber, Jeffrey G.

1990-01-01

Under the Department of Energy's (DOE) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for terrestrial Solar Distributed Heat Receivers. The Stirling engine has been identified by Sandia as one of the most promising engines for terrestrial applications. The Stirling engine also has the potential to meet DOE's performance and cost goals. The NASA Lewis Research Center is conducting Stirling engine technology development activities directed toward a dynamic power source for space applications. Space power systems requirements include high reliability, very long life, low vibration and high efficiency. The free-piston Stirling engine has the potential for future high power space conversion systems, either nuclear or solar powered. Although both applications appear to be quite different, their requirements complement each other. Preliminary designs feature a free-piston Stirling engine, a liquid metal heat transport system, and a means to provide nominally 25 kW electric power to a utility grid while meeting DOE's performance and long term cost goals. The Cummins design incorporates a linear alternator to provide the electrical output, while the STC design generates electrical power indirectly through a hydraulic pump/motor coupled to an induction generator. Both designs for the ASCS's will use technology which can reasonably be expected to be available in the early 1990's.

Preliminary designs for 25 kWe advanced Stirling conversion systems for dish electric applications

NASA Astrophysics Data System (ADS)

Shaltens, Richard K.; Schreiber, Jeffrey G.

Under the Department of Energy's (DOE) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for terrestrial Solar Distributed Heat Receivers. The Stirling engine has been identified by Sandia as one of the most promising engines for terrestrial applications. The Stirling engine also has the potential to meet DOE's performance and cost goals. The NASA Lewis Research Center is conducting Stirling engine technology development activities directed toward a dynamic power source for space applications. Space power systems requirements include high reliability, very long life, low vibration and high efficiency. The free-piston Stirling engine has the potential for future high power space conversion systems, either nuclear or solar powered. Although both applications appear to be quite different, their requirements complement each other. Preliminary designs feature a free-piston Stirling engine, a liquid metal heat transport system, and a means to provide nominally 25 kW electric power to a utility grid while meeting DOE's performance and long term cost goals. The Cummins design incorporates a linear alternator to provide the electrical output, while the STC design generates electrical power indirectly through a hydraulic pump/motor coupled to an induction generator. Both designs for the ASCS's will use technology which can reasonably be expected to be available in the early 1990's.

Preliminary designs for 25 kWe advanced Stirling conversion systems for dish electric applications

NASA Technical Reports Server (NTRS)

Shaltens, Richard K.; Schreiber, Jeffrey G.

1990-01-01

Under the Department of Energy's (DOE) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for terrestrial Solar Distributed Heat Receivers. The Stirling engine has been identified by Sandia as one of the most promising engines for terrestrial applications. The Stirling engine also has the potential to meet DOE's performance and cost goals. The NASA Lewis Research Center is conducting Stirling engine technology development activities directed toward a dynamic power source for space applications. Space power systems requirements include high reliability, very long life, low vibration and high efficiency. The free-piston Stirling engine has the potential for future high power space conversion systems, either nuclear or solar powered. Although both applications appear to be quite different, their requirements complement each other. Preliminary designs feature a free-piston Stirling engine, a liquid metal heat transport system, and a means to provide nominally 25 kW electric power to a utility grid while meeting DOE's performance and long term cost goals. The Cummins design incorporates a linear alternator to provide the electrical output, while the STC design generates electrical power indirectly through a hydraulic pump/motor coupled to an induction generator. Both designs for the ASCS's will use technology which can reasonably be expected to be available in the early 1990's

Thermal Expansion Behavior of Hot-Pressed Engineered Matrices

NASA Technical Reports Server (NTRS)

Raj, S. V.

2016-01-01

Advanced engineered matrix composites (EMCs) require that the coefficient of thermal expansion (CTE) of the engineered matrix (EM) matches those of the fiber reinforcements as closely as possible in order to reduce thermal compatibility strains during heating and cooling of the composites. The present paper proposes a general concept for designing suitable matrices for long fiber reinforced composites using a rule of mixtures (ROM) approach to minimize the global differences in the thermal expansion mismatches between the fibers and the engineered matrix. Proof-of-concept studies were conducted to demonstrate the validity of the concept.

Further Investigations of Hypersonic Engine Seals

NASA Technical Reports Server (NTRS)

Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; DeMange, Jeffrey J.

2004-01-01

Durable, flexible sliding seals are required in advanced hypersonic engines to seal the perimeters of movable engine ramps for efficient, safe operation in high heat flux environments at temperatures of 2000 to 2500 F. Current seal designs do not meet the demanding requirements for future engines, so NASA's Glenn Research Center is developing advanced seals and preloading devices to overcome these shortfalls. An advanced ceramic wafer seal design and two silicon nitride compression spring designs were evaluated in a series of compression, scrub, and flow tests. Silicon nitride wafer seals survived 2000 in. (50.8 m) of scrubbing at 2000 F against a silicon carbide rub surface with no chips or signs of damage. Flow rates measured for the wafers before and after scrubbing were almost identical and were up to 32 times lower than those recorded for the best braided rope seal flow blockers. Silicon nitride compression springs showed promise conceptually as potential seal preload devices to help maintain seal resiliency.

Thin Film Sensors for Surface Measurements

NASA Technical Reports Server (NTRS)

Martin, Lisa C.; Wrbanek, John D.; Fralick, Gustave C.

2001-01-01

Advanced thin film sensors that can provide accurate surface temperature, strain, and heat flux measurements have been developed at NASA Glenn Research Center. These sensors provide minimally intrusive characterization of advanced propulsion materials and components in hostile, high-temperature environments as well as validation of propulsion system design codes. The sensors are designed for applications on different material systems and engine components for testing in engine simulation facilities. Thin film thermocouples and strain gauges for the measurement of surface temperature and strain have been demonstrated on metals, ceramics and advanced ceramic-based composites of various component configurations. Test environments have included both air-breathing and space propulsion-based engine and burner rig environments at surface temperatures up to 1100 C and under high gas flow and pressure conditions. The technologies developed for these sensors as well as for a thin film heat flux gauge have been integrated into a single multifunctional gauge for the simultaneous real-time measurement of surface temperature, strain, and heat flux. This is the first step toward the development of smart sensors with integrated signal conditioning and high temperature electronics that would have the capability to provide feedback to the operating system in real-time. A description of the fabrication process for the thin film sensors and multifunctional gauge will be provided. In addition, the material systems on which the sensors have been demonstrated, the test facilities and the results of the tests to-date will be described. Finally, the results will be provided of the current effort to demonstrate the capabilities of the multifunctional gauge.

Advanced Environmental Barrier Coating Development for SiC-SiC Ceramic Matrix Composite Components

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan; Hurst, Janet B.; Halbig, Michael Charles; Puleo, Bernadette J.; Costa, Gustavo; Mccue, Terry R.

2017-01-01

This presentation reviews the NASA advanced environmental barrier coating (EBC) system development for SiC-SiC Ceramic Matrix Composite (CMC) combustors particularly under the NASA Environmentally Responsible Aviation, Fundamental Aeronautics and Transformative Aeronautics Concepts Programs. The emphases have been placed on the current design challenges of the 2700-3000F capable environmental barrier coatings for low NOX emission combustors for next generation turbine engines by using advanced plasma spray based processes, and the coating processing and integration with SiC-SiC CMCs and component systems. The developments also have included candidate coating composition system designs, degradation mechanisms, performance evaluation and down-selects; the processing optimizations using TriplexPro Air Plasma Spray Low Pressure Plasma Spray (LPPS), Plasma Spray Physical Vapor Deposition and demonstration of EBC-CMC systems. This presentation also highlights the EBC-CMC system temperature capability and durability improvements under the NASA development programs, as demonstrated in the simulated engine high heat flux, combustion environments, in conjunction with high heat flux, mechanical creep and fatigue loading testing conditions.

The Role of Diesel Engines in Early Submarine Development

DTIC Science & Technology

2010-04-26

advantage of advances in metallurgical technology, could not match the superior technology in casting processes, alloy development, and heat treatments...metallurgical technology. NELSECO had the German plans and assistance from German engineers, but the foundries could not duplicate the casting to German...that the Germans and other European countries possessed. The U.S. commercial foundries did not want to undertake the risky development casting of low

Small engine technology programs

NASA Technical Reports Server (NTRS)

Niedzwiecki, Richard W.

1990-01-01

Described here is the small engine technology program being sponsored at the Lewis Research Center. Small gas turbine research is aimed at general aviation, commuter aircraft, rotorcraft, and cruise missile applications. The Rotary Engine program is aimed at supplying fuel flexible, fuel efficient technology to the general aviation industry, but also has applications to other missions. The Automotive Gas Turbine (AGT) and Heavy-Duty Diesel Transport Technology (HDTT) programs are sponsored by DOE. The Compound Cycle Engine program is sponsored by the Army. All of the programs are aimed towards highly efficient engine cycles, very efficient components, and the use of high temperature structural ceramics. This research tends to be generic in nature and has broad applications. The HDTT, rotary technology, and the compound cycle programs are all examining approaches to minimum heat rejection, or 'adiabatic' systems employing advanced materials. The AGT program is also directed towards ceramics application to gas turbine hot section components. Turbomachinery advances in the gas turbine programs will benefit advanced turbochargers and turbocompounders for the intermittent combustion systems, and the fundamental understandings and analytical codes developed in the research and technology programs will be directly applicable to the system projects.

An extended supersonic combustion model for the dynamic analysis of hypersonic vehicles

NASA Technical Reports Server (NTRS)

Bossard, J. A.; Peck, R. E.; Schmidt, D. K.

1993-01-01

The development of an advanced dynamic model for aeroelastic hypersonic vehicles powered by air breathing engines requires an adequate engine model. This report provides a discussion of some of the more important features of supersonic combustion and their relevance to the analysis and design of supersonic ramjet engines. Of particular interest are those aspects of combustion that impact the control of the process. Furthermore, the report summarizes efforts to enhance the aeropropulsive/aeroelastic dynamic model developed at the Aerospace Research Center of Arizona State University by focusing on combustion and improved modeling of this flow. The expanded supersonic combustor model described here has the capability to model the effects of friction, area change, and mass addition, in addition to the heat addition process. A comparison is made of the results from four cases: (1) heat addition only; (2) heat addition plus friction; (3) heat addition, friction, and area reduction, and (4) heat addition, friction, area reduction, and mass addition. The relative impact of these effects on the Mach number, static temperature, and static pressure distributions within the combustor are then shown. Finally, the effects of frozen versus equilibrium flow conditions within the exhaust plume is discussed.

Evaluation of capillary reinforced composites

NASA Technical Reports Server (NTRS)

Cahill, J. E.; Halase, J. F.; South, W. K.; Stoffer, L. J.

1985-01-01

Anti-icing of the inlet of jet engines is generally performed with high pressure heated air that is directed forward from the compressor through a series of pipes to various manifolds located near the structures to be anti-iced. From these manifolds, the air is directed to all flowpath surfaces that may be susceptible to ice formation. There the anti-icing function may be performed by either heat conduction or film heating. Unfortunately, the prospect of utilizing lighweight, high strength composites for inlet structures of jet engines has been frustrated by the low transverse thermal conductivity of such materials. It was the objective of this program to develop an advanced materials and design concept for anti-icing composite structures. The concept that was evaluated used capillary glass tubes embedded on the surface of a composite structure with heated air ducted through the tubes. An analytical computer program was developed to predict the anti-icing performance of such tubes and a test program was conducted to demonstrate actual performance of this system. Test data and analytical code results were in excellent agreement. Both indicate feasibility of using capillary tubes for surface heating as a means for composite engine structures to combat ice accumulation.

Orbit Transfer Vehicle (OTV) advanced expander cycle engine point design study. Volume 2: Study results

NASA Technical Reports Server (NTRS)

1980-01-01

Detailed computer models of the engine were developed to predict both the steady state and transient operation of the engine system. Mechanical design layout drawings were prepared for the following components: thrust chamber and nozzle; extendible nozzle actuating mechanism and seal; LOX turbopump and boost pump; hydrogen turbopump and boost pump; and the propellant control valves. The necessary heat transfer, stress, fluid flow, dynamic, and performance analyses were performed to support the mechanical design.

KSC-95pc586

NASA Image and Video Library

1995-04-17

KENNEDY SPACE CENTER, FLA. - Space Shuttle Main Engine (SSME) No. 2036, the first of the new Block 1 engines to fly, awaits installation into position one of the orbiter Discovery in Orbiter Processing Facility 2 during preparation of the spaceplane for the STS-70 mission. The advanced powerplant features a new high-pressure liquid oxygen turbopump, a two-duct powerhead, a baffleless main injector, a single-coil heat exchanger and start sequence modifications. These modifications are designed to improve both engine performance and safety.

NASA Orbit Transfer Rocket Engine Technology Program

NASA Technical Reports Server (NTRS)

1984-01-01

The advanced expander cycle engine with a 15,000 lb thrust level and a 6:1 mixture ratio and optimized performance was used as the baseline for a design study of the hydrogen/oxgyen propulsion system for the orbit transfer vehicle. The critical components of this engine are the thrust chamber, the turbomachinery, the extendible nozzle system, and the engine throttling system. Turbomachinery technology is examined for gears, bearing, seals, and rapid solidification rate turbopump shafts. Continuous throttling concepts are discussed. Components of the OTV engine described include the thrust chamber/nozzle assembly design, nozzles, the hydrogen regenerator, the gaseous oxygen heat exchanger, turbopumps, and the engine control valves.

Do-It-Yourself Additives Recharge Auto Air Conditioning

NASA Technical Reports Server (NTRS)

2010-01-01

In planning for a return mission to the Moon, NASA aimed to improve the thermal control systems that keep astronauts comfortable and cool while inside a spacecraft. Goddard Space Flight Center awarded a Small Business Innovation Research (SBIR) contract to Mainstream Engineering Corporation, of Rockledge, Florida, to develop a chemical/mechanical heat pump. IDQ Inc., of Garland, Texas, exclusively licensed the technology and incorporates it into its line of Arctic Freeze products for automotive air conditioning applications. While working on the design, Mainstream Engineering came up with a unique liquid additive called QwikBoost to enhance the performance of the advanced heat pump design.

Cogeneration Technology Alternatives Study (CTAS). Volume 1: Summary

NASA Technical Reports Server (NTRS)

Barna, G. J.; Burns, R. K.; Sagerman, G. D.

1980-01-01

Various advanced energy conversion systems that can use coal or coal-derived fuels for industrial cogeneration applications were compared to provide information needed by DOE to establish research and development funding priorities for advanced-technology systems that could significantly advance the use of coal or coal-derived fuels in industrial cogeneration. Steam turbines, diesel engines, open-cycle gas turbines, combined cycles, closed-cycle gas turbines, Stirling engines, phosphoric acid fuel cells, molten carbonate fuel cells, and thermionics were studied with technology advancements appropriate for the 1985-2000 time period. The various advanced systems were compared and evaluated for wide diversity of representative industrial plants on the basis of fuel energy savings, annual energy cost savings, emissions savings, and rate of return on investment as compared with purchasing electricity from a utility and providing process heat with an on-site boiler. Also included in the comparisons and evaluations are results extrapolated to the national level.

Cogeneration Technology Alternatives Study (CTAS). Volume 2: Comparison and evaluation of results

NASA Technical Reports Server (NTRS)

1984-01-01

CTAS compared and evaluated various advanced energy conversion systems that can use coal or coal-derived fuels for industrial cogeneration applications. The principal aim of the study was to provide information needed by DOE to establish research and development (R&D) funding priorities for advanced-technology systems that could significantly advance the use of coal or coal-derived fuels in industrial cogeneration. Steam turbines, diesel engines, open-cycle gas turbines, combined cycles, closed-cycle gas turbines, Stirling engines, phosphoric acid fuel cells, molten carbonate fuel cells, and thermionics were studied with technology advancements appropriate for the 1985-2000 time period. The various advanced systems were compared and evaluated for a wide diversity of representative industrial plants on the basis of fuel energy savings, annual energy cost savings, emissions savings, and rate of return on investment (ROI) as compared with purchasing electricity from a utility and providing process heat with an on-site boiler.

Selection Criteria and Screening of Potential Biomass-Derived Streams as Fuel Blendstocks for Advanced Spark-Ignition Engines

DOE PAGES

McCormick, Robert L.; Fioroni, Gina; Fouts, Lisa; ...

2017-03-28

Here, we describe a study to identify potential biofuels that enable advanced spark ignition (SI) engine efficiency strategies to be pursued more aggressively. A list of potential biomass-derived blendstocks was developed. An online database of properties and characteristics of these bioblendstocks was created and populated. Fuel properties were determined by measurement, model prediction, or literature review. Screening criteria were developed to determine if a bioblendstock met the requirements for advanced SI engines. Criteria included melting point (or cloud point) < -10 degrees C and boiling point (or T90) <165 degrees C. Compounds insoluble or poorly soluble in hydrocarbon were eliminatedmore » from consideration, as were those known to cause corrosion (carboxylic acids or high acid number mixtures) and those with hazard classification as known or suspected carcinogens or reproductive toxins. Compounds predicted to be less anaerobically biodegradable than methyl-tert-butyl ether with water solubility greater than 10,000 mg/L were also eliminated. A minimum Research octane number (RON) of 98 was applied. These criteria produced a list of 40 bioblendstocks with promising properties. Additional property data, including Motor octane number (MON), heat of vaporization, and lower heating value, were acquired for these bioblendstocks. A subset of the bioblendstocks representing all functional groups were blended into gasoline or a gasoline surrogate to measure their effect on vapor pressure, distillation curve, oxidation stability, RON, and MON. For blending into a conventional or reformulated blendstock for E10 blending, ethanol, 2-butanol, isobutanol, and diisobutylene have the most desirable properties for blending of a high-octane advanced SI engine fuel.« less

Selection Criteria and Screening of Potential Biomass-Derived Streams as Fuel Blendstocks for Advanced Spark-Ignition Engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCormick, Robert L.; Fioroni, Gina; Fouts, Lisa

Here, we describe a study to identify potential biofuels that enable advanced spark ignition (SI) engine efficiency strategies to be pursued more aggressively. A list of potential biomass-derived blendstocks was developed. An online database of properties and characteristics of these bioblendstocks was created and populated. Fuel properties were determined by measurement, model prediction, or literature review. Screening criteria were developed to determine if a bioblendstock met the requirements for advanced SI engines. Criteria included melting point (or cloud point) < -10 degrees C and boiling point (or T90) <165 degrees C. Compounds insoluble or poorly soluble in hydrocarbon were eliminatedmore » from consideration, as were those known to cause corrosion (carboxylic acids or high acid number mixtures) and those with hazard classification as known or suspected carcinogens or reproductive toxins. Compounds predicted to be less anaerobically biodegradable than methyl-tert-butyl ether with water solubility greater than 10,000 mg/L were also eliminated. A minimum Research octane number (RON) of 98 was applied. These criteria produced a list of 40 bioblendstocks with promising properties. Additional property data, including Motor octane number (MON), heat of vaporization, and lower heating value, were acquired for these bioblendstocks. A subset of the bioblendstocks representing all functional groups were blended into gasoline or a gasoline surrogate to measure their effect on vapor pressure, distillation curve, oxidation stability, RON, and MON. For blending into a conventional or reformulated blendstock for E10 blending, ethanol, 2-butanol, isobutanol, and diisobutylene have the most desirable properties for blending of a high-octane advanced SI engine fuel.« less

Lightweight thermal energy recovery system based on shape memory alloys: a DOE ARPA-E initiative

NASA Astrophysics Data System (ADS)

Browne, Alan L.; Keefe, Andrew C.; Alexander, Paul W.; Mankame, Nilesh; Usoro, Patrick; Johnson, Nancy L.; Aase, Jan; Sarosi, Peter; McKnight, Geoffrey P.; Herrera, Guillermo; Churchill, Christopher; Shaw, John; Brown, Jeff

2012-04-01

Over 60% of energy that is generated is lost as waste heat with close to 90% of this waste heat being classified as low grade being at temperatures less than 200°C. Many technologies such as thermoelectrics have been proposed as means for harvesting this lost thermal energy. Among them, that of SMA (shape memory alloy) heat engines appears to be a strong candidate for converting this low grade thermal output to useful mechanical work. Unfortunately, though proposed initially in the late 60's and the subject of significant development work in the 70's, significant technical roadblocks have existed preventing this technology from moving from a scientific curiosity to a practical reality. This paper/presentation provides an overview of the work performed on SMA heat engines under the US DOE (Department of Energy) ARPA-E (Advanced Research Projects Agency - Energy) initiative. It begins with a review of the previous art, covers the identified technical roadblocks to past advancement, presents the solution path taken to remove these roadblocks, and describes significant breakthroughs during the project. The presentation concludes with details of the functioning prototypes developed, which, being able to operate in air as well as fluids, dramatically expand the operational envelop and make significant strides towards the ultimate goal of commercial viability.

Simulation of the Effects of Cooling Techniques on Turbine Blade Heat Transfer

NASA Astrophysics Data System (ADS)

Shaw, Vince; Fatuzzo, Marco

Increases in the performance demands of turbo machinery has stimulated the development many new technologies over the last half century. With applications that spread beyond marine, aviation, and power generation, improvements in gas turbine technologies provide a vast impact. High temperatures within the combustion chamber of the gas turbine engine are known to cause an increase in thermal efficiency and power produced by the engine. However, since operating temperatures of these engines reach above 1000 K within the turbine section, the need for advances in material science and cooling techniques to produce functioning engines under these high thermal and dynamic stresses is crucial. As with all research and development, costs related to the production of prototypes can be reduced through the use of computational simulations. By making use of Ansys Simulation Software, the effects of turbine cooling techniques were analyzed. Simulation of the Effects of Cooling Techniques on Turbine Blade Heat Transfer.

Turbine blade and vane heat flux sensor development, phase 1

NASA Technical Reports Server (NTRS)

Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

1984-01-01

Heat flux sensors available for installation in the hot section airfoils of advanced aircraft gas turbine engines were developed. Two heat flux sensors were designed, fabricated, calibrated, and tested. Measurement techniques are compared in an atmospheric pressure combustor rig test. Sensors, embedded thermocouple and the Gordon gauge, were fabricated that met the geometric and fabricability requirements and could withstand the hot section environmental conditions. Calibration data indicate that these sensors yielded repeatable results and have the potential to meet the accuracy goal of measuring local heat flux to within 5%. Thermal cycle tests and thermal soak tests indicated that the sensors are capable of surviving extended periods of exposure to the environment conditions in the turbine. Problems in calibration of the sensors caused by severe non-one dimensional heat flow were encountered. Modifications to the calibration techniques are needed to minimize this problem and proof testing of the sensors in an engine is needed to verify the designs.

Turbine blade and vane heat flux sensor development, phase 1

NASA Astrophysics Data System (ADS)

Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

1984-08-01

Heat flux sensors available for installation in the hot section airfoils of advanced aircraft gas turbine engines were developed. Two heat flux sensors were designed, fabricated, calibrated, and tested. Measurement techniques are compared in an atmospheric pressure combustor rig test. Sensors, embedded thermocouple and the Gordon gauge, were fabricated that met the geometric and fabricability requirements and could withstand the hot section environmental conditions. Calibration data indicate that these sensors yielded repeatable results and have the potential to meet the accuracy goal of measuring local heat flux to within 5%. Thermal cycle tests and thermal soak tests indicated that the sensors are capable of surviving extended periods of exposure to the environment conditions in the turbine. Problems in calibration of the sensors caused by severe non-one dimensional heat flow were encountered. Modifications to the calibration techniques are needed to minimize this problem and proof testing of the sensors in an engine is needed to verify the designs.

Upgraded automotive gas turbine engine design and development program, volume 2

NASA Technical Reports Server (NTRS)

Wagner, C. E. (Editor); Pampreen, R. C. (Editor)

1979-01-01

Results are presented for the design and development of an upgraded engine. The design incorporated technology advancements which resulted from development testing on the Baseline Engine. The final engine performance with all retro-fitted components from the development program showed a value of 91 HP at design speed in contrast to the design value of 104 HP. The design speed SFC was 0.53 versus the goal value of 0.44. The miss in power was primarily due to missing the efficiency targets of small size turbomachinery. Most of the SFC deficit was attributed to missed goals in the heat recovery system relative to regenerator effectiveness and expected values of heat loss. Vehicular fuel consumption, as measured on a chassis dynamometer, for a vehicle inertia weight of 3500 lbs., was 15 MPG for combined urban and highway driving cycles. The baseline engine achieved 8 MPG with a 4500 lb. vehicle. Even though the goal of 18.3 MPG was not achieved with the upgraded engine, there was an improvement in fuel economy of 46% over the baseline engine, for comparable vehicle inertia weight.

The Prediction of Nozzle Performance and Heat Transfer in Hydrogen/Oxygen Rocket Engines with Transpiration Cooling, Film Cooling, and High Area Ratios

NASA Technical Reports Server (NTRS)

Kacynski, Kenneth J.; Hoffman, Joe D.

1994-01-01

An advanced engineering computational model has been developed to aid in the analysis of chemical rocket engines. The complete multispecies, chemically reacting and diffusing Navier-Stokes equations are modelled, including the Soret thermal diffusion and Dufour energy transfer terms. Demonstration cases are presented for a 1030:1 area ratio nozzle, a 25 lbf film-cooled nozzle, and a transpiration-cooled plug-and-spool rocket engine. The results indicate that the thrust coefficient predictions of the 1030:1 nozzle and the film-cooled nozzle are within 0.2 to 0.5 percent, respectively, of experimental measurements. Further, the model's predictions agree very well with the heat transfer measurements made in all of the nozzle test cases. It is demonstrated that thermal diffusion has a significant effect on the predicted mass fraction of hydrogen along the wall of the nozzle and was shown to represent a significant fraction of the diffusion fluxes occurring in the transpiration-cooled rocket engine.

Performance of an Advanced Stirling Convertor Based on Heat Flux Sensor Measurements

NASA Technical Reports Server (NTRS)

Wilson, Dcott D.

2012-01-01

The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two highefficiency Advanced Stirling Convertors (ASCs), developed by Sunpower, Inc., and NASA Glenn Research Center. The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot-end and cold-end temperatures, and specified electrical power output for a given heat input. It is difficult to measure heat input to Stirling convertors due to the complex geometries of the hot components, temperature limits of sensor materials, and invasive integration of sensors. A thin-film heat flux sensor was used to directly measure heat input to an ASC. The effort succeeded in designing and fabricating unique sensors, which were integrated into a Stirling convertor ground test and exposed to test temperatures exceeding 700 C in air for 10,000 hr. Sensor measurements were used to calculate thermal efficiency for ASC-E (Engineering Unit) #1 and #4. The post-disassembly condition of the sensors is also discussed.

Performance of an Advanced Stirling Convertor Based on Heat Flux Sensor Measurements

NASA Technical Reports Server (NTRS)

Wilson, Scott D.

2012-01-01

The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two high-efficiency Advanced Stirling Convertors (ASCs), developed by Sunpower, Inc., and NASA Glenn Research Center. The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot-end and cold-end temperatures, and specified electrical power output for a given heat input. It is difficult to measure heat input to Stirling convertors due to the complex geometries of the hot components, temperature limits of sensor materials, and invasive integration of sensors. A thin-film heat flux sensor was used to directly measure heat input to an ASC. The effort succeeded in designing and fabricating unique sensors, which were integrated into a Stirling convertor ground test and exposed to test temperatures exceeding 700 C in air for 10,000 hr. Sensor measurements were used to calculate thermal efficiency for ASC-E (Engineering Unit) #1 and #4. The post-disassembly condition of the sensors is also discussed.

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.

Applicability of advanced automotive heat engines to solar thermal power

NASA Technical Reports Server (NTRS)

Beremand, D. G.; Evans, D. G.; Alger, D. L.

1981-01-01

The requirements of a solar thermal power system are reviewed and compared with the predicted characteristics of automobile engines under development. A good match is found in terms of power level and efficiency when the automobile engines, designed for maximum powers of 65-100 kW (87 to 133 hp) are operated to the nominal 20-40 kW electric output requirement of the solar thermal application. At these reduced power levels it appears that the automotive gas turbine and Stirling engines have the potential to deliver the 40+ percent efficiency goal of the solar thermal program.

Applicability of advanced automotive heat engines to solar thermal power

NASA Astrophysics Data System (ADS)

Beremand, D. G.; Evans, D. G.; Alger, D. L.

The requirements of a solar thermal power system are reviewed and compared with the predicted characteristics of automobile engines under development. A good match is found in terms of power level and efficiency when the automobile engines, designed for maximum powers of 65-100 kW (87 to 133 hp) are operated to the nominal 20-40 kW electric output requirement of the solar thermal application. At these reduced power levels it appears that the automotive gas turbine and Stirling engines have the potential to deliver the 40+ percent efficiency goal of the solar thermal program.

ALTERNATIVE AVIATION FUELS FOR USE IN MILITARY APUS AND ENGINES VERSATILE AFFORDABLE ADVANCED TURBINE ENGINE (VAATE), PHASE II AND III. Delivery Order 0007: Alternative Aviation Fuels for Use in Military Auxiliary Power Units (APUs) and Engines

DTIC Science & Technology

2017-06-03

used and the test cell had been thoroughly purged of the previous fuel, and to provide fuel properties needed to run the test. Posttest fuel samples...altitude hot day generator load. All tests were run at actual engine conditions (not scaled). Fuel flows were adjusted to provide a constant heat input...blends had slightly higher temperatures at the blade tip location and slightly lower temperatures at the blade hub location, but these differences are

Opportunities for research in aerothermodynamics

NASA Technical Reports Server (NTRS)

Graham, R. W.

1983-01-01

"Aerothermodynamics' involves the disciplines of chemistry, thermodynamics, fluid mechanics and heat transfer which have collaborative importance in propulsion systems. There are growing opportunities for the further application of these disciplines to improve the methodology for the design of advanced gas turbines; particularly, the combustor and turbine. Design procedures follow empirical or cut and try guidelines. The tremendous advances in computational analysis and in instrumentation techniques hold promise for research answers to complex physical processes that are currently not well understood. The transfer of basic research understanding to engineering design should result in shorter, less expensive development commitments for engines. The status and anticipated opportunities in research topics relevant to combustors and turbines is reviewed.

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.

Design of a Facility to Test the Advanced Stirling Radioisotope Generator Engineering Unit

NASA Technical Reports Server (NTRS)

Lewandowski, Edward J.; Schreiber, Jeffrey G.; Oriti, Salvatore M.; Meer, David W.; Brace, Michael H.; Dugala, Gina

2010-01-01

The Advanced Stirling Radioisotope Generator (ASRG), a high efficiency generator, is being considered for space missions. An engineering unit, the ASRG engineering unit (EU), was designed and fabricated by Lockheed Martin under contract to the Department of Energy. This unit is currently under extended operation test at the NASA Glenn Research Center (GRC) to generate performance data and validate the life and reliability predictions for the generator and the Stirling convertors. A special test facility was designed and built for the ASRG EU. This paper summarizes details of the test facility design, including the mechanical mounting, heat-rejection system, argon system, control systems, and maintenance. The effort proceeded from requirements definition through design, analysis, build, and test. Initial testing and facility performance results are discussed.

Advanced diesel electronic fuel injection and turbocharging

NASA Astrophysics Data System (ADS)

Beck, N. J.; Barkhimer, R. L.; Steinmeyer, D. C.; Kelly, J. E.

1993-12-01

The program investigated advanced diesel air charging and fuel injection systems to improve specific power, fuel economy, noise, exhaust emissions, and cold startability. The techniques explored included variable fuel injection rate shaping, variable injection timing, full-authority electronic engine control, turbo-compound cooling, regenerative air circulation as a cold start aid, and variable geometry turbocharging. A Servojet electronic fuel injection system was designed and manufactured for the Cummins VTA-903 engine. A special Servojet twin turbocharger exhaust system was also installed. A series of high speed combustion flame photos was taken using the single cylinder optical engine at Michigan Technological University. Various fuel injection rate shapes and nozzle configurations were evaluated. Single-cylinder bench tests were performed to evaluate regenerative inlet air heating techniques as an aid to cold starting. An exhaust-driven axial cooling air fan was manufactured and tested on the VTA-903 engine.

Illustrating Thermodynamic Concepts Using a Hero's Engine

NASA Astrophysics Data System (ADS)

Muiño, Pedro L.; Hodgson, James R.

2000-05-01

A modified Hero's engine is used to illustrate concepts of thermodynamics and engineering design suitable for introductory chemistry courses and more advanced physical chemistry courses. The engine is a boiler made of Pyrex with two off-center nozzles. Upon boiling, the vapor exits the nozzles, creating two opposite, off-center forces that result in a circular motion by the engine around the vertical axis. The engine is suspended from a horizontal bar by means of two parallel threads. The rotation of the engine results in the twisting of the threads, with two important effects: the engine is raised vertically, and potential energy is stored in the coiling of the threads. When the engine is raised, it is removed from the heating source. This stops the boiling. The stored potential energy is then released into kinetic energy; that is, the threads uncoil, and the engine rotates in the opposite direction. This lowers the engine into the flame, so the water resumes boiling and the engine can be raised again. This cycle continues until all the liquid water is vaporized. This demonstration is suitable to illustrate concepts like gas expansion, gas cooling through expansion (Joule-Thompson experiment), conversion of heat to work, interconversion between kinetic energy and potential energy, and feedback mechanisms.

Enhancement and Extension of Porosity Model in the FDNS-500 Code to Provide Enhanced Simulations of Rocket Engine Components

NASA Technical Reports Server (NTRS)

Cheng, Gary

2003-01-01

In the past, the design of rocket engines has primarily relied on the cold flow/hot fire test, and the empirical correlations developed based on the database from previous designs. However, it is very costly to fabricate and test various hardware designs during the design cycle, whereas the empirical model becomes unreliable in designing the advanced rocket engine where its operating conditions exceed the range of the database. The main goal of the 2nd Generation Reusable Launching Vehicle (GEN-II RLV) is to reduce the cost per payload and to extend the life of the hardware, which poses a great challenge to the rocket engine design. Hence, understanding the flow characteristics in each engine components is thus critical to the engine design. In the last few decades, the methodology of computational fluid dynamics (CFD) has been advanced to be a mature tool of analyzing various engine components. Therefore, it is important for the CFD design tool to be able to properly simulate the hot flow environment near the liquid injector, and thus to accurately predict the heat load to the injector faceplate. However, to date it is still not feasible to conduct CFD simulations of the detailed flowfield with very complicated geometries such as fluid flow and heat transfer in an injector assembly and through a porous plate, which requires gigantic computer memories and power to resolve the detailed geometry. The rigimesh (a sintered metal material), utilized to reduce the heat load to the faceplate, is one of the design concepts for the injector faceplate of the GEN-II RLV. In addition, the injector assembly is designed to distribute propellants into the combustion chamber of the liquid rocket engine. A porosity mode thus becomes a necessity for the CFD code in order to efficiently simulate the flow and heat transfer in these porous media, and maintain good accuracy in describing the flow fields. Currently, the FDNS (Finite Difference Navier-Stakes) code is one of the CFD codes which are most widely used by research engineers at NASA Marshall Space Flight Center (MSFC) to simulate various flow problems related to rocket engines. The objective of this research work during the 10-week summer faculty fellowship program was to 1) debug the framework of the porosity model in the current FDNS code, and 2) validate the porosity model by simulating flows through various porous media such as tube banks and porous plate.

Development of heat flux sensors for turbine airfoils

NASA Astrophysics Data System (ADS)

Atkinson, William H.; Cyr, Marcia A.; Strange, Richard R.

1985-10-01

The objectives of this program are to develop heat flux sensors suitable for installation in hot section airfoils of advanced aircraft turbine engines and to experimentally verify the operation of these heat flux sensors in a cylinder in a cross flow experiment. Embedded thermocouple and Gardon gauge sensors were developed and fabricated into both blades and vanes. These were then calibrated using a quartz lamp bank heat source and finally subjected to thermal cycle and thermal soak testing. These sensors were also fabricated into cylindrical test pieces and tested in a burner exhaust to verify heat flux measurements produced by these sensors. The results of the cylinder in cross flow tests are given.

Development of heat flux sensors for turbine airfoils

NASA Technical Reports Server (NTRS)

Atkinson, William H.; Cyr, Marcia A.; Strange, Richard R.

1985-01-01

The objectives of this program are to develop heat flux sensors suitable for installation in hot section airfoils of advanced aircraft turbine engines and to experimentally verify the operation of these heat flux sensors in a cylinder in a cross flow experiment. Embedded thermocouple and Gardon gauge sensors were developed and fabricated into both blades and vanes. These were then calibrated using a quartz lamp bank heat source and finally subjected to thermal cycle and thermal soak testing. These sensors were also fabricated into cylindrical test pieces and tested in a burner exhaust to verify heat flux measurements produced by these sensors. The results of the cylinder in cross flow tests are given.

Ultra-high heat flux cooling characteristics of cryogenic micro-solid nitrogen particles and its application to semiconductor wafer cleaning technology

NASA Astrophysics Data System (ADS)

Ishimoto, Jun; Oh, U.; Guanghan, Zhao; Koike, Tomoki; Ochiai, Naoya

2014-01-01

The ultra-high heat flux cooling characteristics and impingement behavior of cryogenic micro-solid nitrogen (SN2) particles in relation to a heated wafer substrate were investigated for application to next generation semiconductor wafer cleaning technology. The fundamental characteristics of cooling heat transfer and photoresist removal-cleaning performance using micro-solid nitrogen particulate spray impinging on a heated substrate were numerically investigated and experimentally measured by a new type of integrated computational-experimental technique. This study contributes not only advanced cryogenic cooling technology for high thermal emission devices, but also to the field of nano device engineering including the semiconductor wafer cleaning technology.

Overview of aerothermodynamic loads definition study

NASA Technical Reports Server (NTRS)

Gaugler, Raymond E.

1991-01-01

The objective of the Aerothermodynamic Loads Definition Study is to develop methods of accurately predicting the operating environment in advanced Earth-to-Orbit (ETO) propulsion systems, such as the Space Shuttle Main Engine (SSME) powerhead. Development of time averaged and time dependent three dimensional viscous computer codes as well as experimental verification and engine diagnostic testing are considered to be essential in achieving that objective. Time-averaged, nonsteady, and transient operating loads must all be well defined in order to accurately predict powerhead life. Described here is work in unsteady heat flow analysis, improved modeling of preburner flow, turbulence modeling for turbomachinery, computation of three dimensional flow with heat transfer, and unsteady viscous multi-blade row turbine analysis.

Evaluation of advanced regenerator systems

NASA Technical Reports Server (NTRS)

Cook, J. A.; Fucinari, C. A.; Lingscheit, J. N.; Rahnke, C. J.

1978-01-01

The major considerations are discussed which will affect the selection of a ceramic regenerative heat exchanger for an improved 100 HP automotive gas turbine engine. The regenerator considered for this application is about 36cm in diameter. Regenerator comparisons are made on the basis of material, method of fabrication, cost, and performance. A regenerator inlet temperature of 1000 C is assumed for performance comparisons, and laboratory test results are discussed for material comparisons at 1100 and 1200 C. Engine test results using the Ford 707 industrial gas turbine engine are also discussed.

Small engine technology programs

NASA Technical Reports Server (NTRS)

Niedzwiecki, Richard W.

1987-01-01

Small engine technology programs being conducted at the NASA Lewis Research Center are described. Small gas turbine research is aimed at general aviation, commutercraft, rotorcraft, and cruise missile applications. The Rotary Engine Program is aimed at supplying fuel flexible, fuel efficient technology to the general aviation industry, but also has applications to other missions. There is a strong element of synergism between the various programs in several respects. All of the programs are aimed towards highly efficient engine cycles, very efficient components, and the use of high temperature structural ceramics. This research tends to be generic in nature and has broad applications. The Heavy Duty Diesel Transport (HDTT), rotary technology, and the compound cycle programs are all examining approached to minimum heat rejection, or adiabatic systems employing advanced materials. The Automotive Gas Turbine (AGT) program is also directed towards ceramics application to gas turbine hot section components. Turbomachinery advances in the gas turbines will benefit advanced turbochargers and turbocompounders for the intermittent combustion systems, and the fundamental understandings and analytical codes developed in the research and technology programs will be directly applicable to the system projects.

Development of Advanced In-Cylinder Components and Tribological Systems for Low Heat Rejection Diesel Engines

NASA Technical Reports Server (NTRS)

Yonushonis, T. M.; Wiczynski, P. D.; Myers, M. R.; Anderson, D. D.; McDonald, A. C.; Weber, H. G.; Richardson, D. E.; Stafford, R. J.; Naylor, M. G.

1999-01-01

In-cylinder components and tribological system concepts were designed, fabricated and tested at conditions anticipated for a 55% thermal efficiency heavy duty diesel engine for the year 2000 and beyond. A Cummins L10 single cylinder research engine was used to evaluate a spherical joint piston and connecting rod with 19.3 MPa (2800 psi) peak cylinder pressure capability, a thermal fatigue resistant insulated cylinder head, radial combustion seal cylinder liners, a highly compliant steel top compression ring, a variable geometry turbocharger, and a microwave heated particulate trap. Components successfully demonstrated in the final test included spherical joint connecting rod with a fiber reinforced piston, high conformability steel top rings with wear resistant coatings, ceramic exhaust ports with strategic oil cooling and radial combustion seal cylinder liner with cooling jacket transfer fins. A Cummins 6B diesel was used to develop the analytical methods, materials, manufacturing technology and engine components for lighter weight diesel engines without sacrificing performance or durability. A 6B diesel engine was built and tested to calibrate analytical models for the aluminum cylinder head and aluminum block.

Advancement and Implementation of Integrated Computational Materials Engineering (ICME) for Aerospace Applications

DTIC Science & Technology

2010-03-01

of sub-routines Thermal history • Abaqus FEM engine mature applied within ABAQUS Residual stress & Distortion • Unknown maturity for HTC • Focused...investment. The committee’s ICME vision is comprehensive, expansive , and involves the entire materials community. The scope of this white paper is...Software • Continuum FEM for fluid flow, heat Mold Fill • FEM implementation mature flow and stress analysis Thermal & mushy zone history • Needs

Environmental Stability and Oxidation Behavior of HfO2-Si and YbGd(O) Based Environmental Barrier Coating Systems for SiCSiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Farmer, Serene; McCue, Terry R.; Harder, Bryan; Hurst, Janet B.

2017-01-01

Ceramic environmental barrier coatings (EBC) and SiCSiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft propulsion systems because of their ability to significantly increase engine operating temperatures, improve component durability, reduce engine weight and cooling requirements. Advanced EBC systems for SiCSiC CMC turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant material development challenges for the high temperature CMC components is to develop prime-reliant, environmental durable environmental barrier coating systems. In this paper, the durability and performance of advanced Electron Beam-Physical Vapor Deposition (EB-PVD) NASA HfO2-Si and YbGdSi(O) EBC bond coat top coat systems for SiCSiC CMC have been summarized. The high temperature thermomechanical creep, fatigue and oxidation resistance have been investigated in the laboratory simulated high-heat-flux environmental test conditions. The advanced NASA EBC systems showed promise to achieve 1500C temperature capability, helping enable next generation turbine engines with significantly improved engine component temperature capability and durability.

Development of Advanced Environmental Barrier Coatings for SiC/SiC Composites at NASA GRC: Prime-Reliant Design and Durability Perspectives

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2017-01-01

Environmental barrier coatings (EBCs) are considered technologically important because of the critical needs and their ability to effectively protect the turbine hot-section SiC/SiC ceramic matrix composite (CMC) components in harsh engine combustion environments. The development of NASA's advanced environmental barrier coatings have been aimed at significantly improved the coating system temperature capability, stability, erosion-impact, and CMAS resistance for SiC/SiC turbine airfoil and combustors component applications. The NASA environmental barrier coating developments have also emphasized thermo-mechanical creep and fatigue resistance in simulated engine heat flux and environments. Experimental results and models for advanced EBC systems will be presented to help establishing advanced EBC composition design methodologies, performance modeling and life predictions, for achieving prime-reliant, durable environmental coating systems for 2700-3000 F engine component applications. Major technical barriers in developing environmental barrier coating systems and the coating integration with next generation composites having further improved temperature capability, environmental stability, EBC-CMC fatigue-environment system durability will be discussed.

Bioinspired engineering of thermal materials.

PubMed

Tao, Peng; Shang, Wen; Song, Chengyi; Shen, Qingchen; Zhang, Fangyu; Luo, Zhen; Yi, Nan; Zhang, Di; Deng, Tao

2015-01-21

In the development of next-generation materials with enhanced thermal properties, biological systems in nature provide many examples that have exceptional structural designs and unparalleled performance in their thermal or nonthermal functions. Bioinspired engineering thus offers great promise in the synthesis and fabrication of thermal materials that are difficult to engineer through conventional approaches. In this review, recent progress in the emerging area of bioinspired advanced materials for thermal science and technology is summarized. State-of-the-art developments of bioinspired thermal-management materials, including materials for efficient thermal insulation and heat transfer, and bioinspired materials for thermal/infrared detection, are highlighted. The dynamic balance of bioinspiration and practical engineering, the correlation of inspiration approaches with the targeted applications, and the coexistence of molecule-based inspiration and structure-based inspiration are discussed in the overview of the development. The long-term outlook and short-term focus of this critical area of advanced materials engineering are also presented. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Advanced Vehicle system concepts. [nonpetroleum passenger transportation

NASA Technical Reports Server (NTRS)

Hardy, K. S.; Langendoen, J. M.

1983-01-01

Various nonpetroleum vehicle system concepts for passenger vehicles in the 1990's are being considered as part of the Advanced Vehicle (AV) Assessment at the Jet Propulsion Laboratory. The vehicle system and subsystem performance requirements, the projected characteristics of mature subsystem candidates, and promising systems are presented. The system candidates include electric and hybrid vehicles powered by electricity with or without a nonpetroleum power source. The subsystem candidates include batteries (aqueous-mobile, flow, high-temperature, and metal-air), fuel cells (phosphoric acid, advanced acids, and solid polymer electrolyte), nonpetroleum heat engines, advanced dc and ac propulsion components, power-peaking devices, and transmissions.

Advances in refrigeration and heat transfer engineering

DOE PAGES

Bansal, Pradeep; Cremaschi, Prof. Lorenzo

2015-05-13

This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO 2 may perhaps have beenmore » the most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).« less

Advances in refrigeration and heat transfer engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, Pradeep; Cremaschi, Prof. Lorenzo

This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO 2 may perhaps have beenmore » the most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).« less

Space Software for Automotive Design

NASA Technical Reports Server (NTRS)

1988-01-01

John Thousand of Wolverine Western Corp. put his aerospace group to work on an unfamiliar job, designing a brake drum using computer design techniques. Computer design involves creation of a mathematical model of a product and analyzing its effectiveness in simulated operation. Technique enables study of performance and structural behavior of a number of different designs before settling on a final configuration. Wolverine employees attacked a traditional brake drum problem, the sudden buildup of heat during fast and repeated braking. Part of brake drum not confined tends to change its shape under combination of heat, physical pressure and rotational forces, a condition known as bellmouthing. Since bellmouthing is a major factor in braking effectiveness, a solution of problem would be a major advance in automotive engineering. A former NASA employee, now a Wolverine employee, knew of a series of NASA computer programs ideally suited to confronting bellmouthing. Originally developed as aids to rocket engine nozzle design, it's capable of analyzing problems generated in a rocket engine or automotive brake drum by heat, expansion, pressure and rotational forces. Use of these computer programs led to new brake drum concept featuring a more durable axle, and heat transfer ribs, or fins, on hub of drum.

Peracetic Acid: A Practical Agent for Sterilizing Heat-Labile Polymeric Tissue-Engineering Scaffolds

PubMed Central

Yoganarasimha, Suyog; Trahan, William R.; Best, Al M.; Bowlin, Gary L.; Kitten, Todd O.; Moon, Peter C.

2014-01-01

Advanced biomaterials and sophisticated processing technologies aim at fabricating tissue-engineering scaffolds that can predictably interact within a biological environment at the cellular level. Sterilization of such scaffolds is at the core of patient safety and is an important regulatory issue that needs to be addressed before clinical translation. In addition, it is crucial that meticulously engineered micro- and nano- structures are preserved after sterilization. Conventional sterilization methods involving heat, steam, and radiation are not compatible with engineered polymeric systems because of scaffold degradation and loss of architecture. Using electrospun scaffolds made from polycaprolactone, a low melting polymer, and employing spores of Bacillus atrophaeus as biological indicators, we compared ethylene oxide, autoclaving and 80% ethanol to a known chemical sterilant, peracetic acid (PAA), for their ability to sterilize as well as their effects on scaffold properties. PAA diluted in 20% ethanol to 1000 ppm or above sterilized electrospun scaffolds in 15 min at room temperature while maintaining nano-architecture and mechanical properties. Scaffolds treated with PAA at 5000 ppm were rendered hydrophilic, with contact angles reduced to 0°. Therefore, PAA can provide economical, rapid, and effective sterilization of heat-sensitive polymeric electrospun scaffolds that are used in tissue engineering. PMID:24341350

Family System of Advanced Charring Ablators for Planetary Exploration Missions

NASA Technical Reports Server (NTRS)

Congdon, William M.; Curry, Donald M.

2005-01-01

Advanced Ablators Program Objectives: 1) Flight-ready(TRL-6) ablative heat shields for deep-space missions; 2) Diversity of selection from family-system approach; 3) Minimum weight systems with high reliability; 4) Optimized formulations and processing; 5) Fully characterized properties; and 6) Low-cost manufacturing. Definition and integration of candidate lightweight structures. Test and analysis database to support flight-vehicle engineering. Results from production scale-up studies and production-cost analyses.

Advanced Human Factors Engineering Tool Technologies.

DTIC Science & Technology

1988-03-01

charger/ AC adapter immersible probe air temperature probe surface temperature probe . * Sling psychrometer , MSA or Taylor 1328A * Aspirating... psychrometer , Model PP-100 or CP-147, Psychro-Dyne * Wet-bulb-heat-stress monitor, Model B&K 1219, Briel & Kjaer Transducer, Model B&K MM 0030 (3 each), Brijel

Energy Efficiency on Parade

Science.gov Websites

heating, ventilation and air conditioning (HVAC) systems, structural insulated panels to improve products and systems. NREL building engineers estimate the combination of advanced products and design Building America program manager George James. "All of the technologies and systems used in this house

Development of a Direct Evaporator for the Organic Rankine Cycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donna Post Guillen; Helge Klockow; Matthew Lehar

2011-02-01

This paper describes research and development currently underway to place the evaporator of an Organic Rankine Cycle (ORC) system directly in the path of a hot exhaust stream produced by a gas turbine engine. The main goal of this research effort is to improve cycle efficiency and cost by eliminating the usual secondary heat transfer loop. The project’s technical objective is to eliminate the pumps, heat exchangers and all other added cost and complexity of the secondary loop by developing an evaporator that resides in the waste heat stream, yet virtually eliminates the risk of a working fluid leakage intomore » the gaseous exhaust stream. The research team comprised of Idaho National Laboratory and General Electric Company engineers leverages previous research in advanced ORC technology to develop a new direct evaporator design that will reduce the ORC system cost by up to 15%, enabling the rapid adoption of ORCs for waste heat recovery.« less

Advanced thermal control for spacecraft applications

NASA Astrophysics Data System (ADS)

Hardesty, Robert; Parker, Kelsey

2015-09-01

In optical systems just like any other space borne system, thermal control plays an important role. In fact, most advanced designs are plagued with volume constraints that further complicate the thermal control challenges for even the most experienced systems engineers. Peregrine will present advances in satellite thermal control based upon passive heat transfer technologies to dissipate large thermal loads. This will address the use of 700 W/m K and higher conducting products that are five times better than aluminum on a specific basis providing enabling thermal control while maintaining structural support.

A research program for improving heat transfer prediction for the laminar to turbulent transition region of turbine vanes/blades

NASA Technical Reports Server (NTRS)

Simon, Frederick F.

1993-01-01

A program sponsored by NASA for the investigation of the heat transfer in the transition region of turbine vanes and blades with the objective of improving the capability for predicting heat transfer is described. The accurate prediction of gas-side heat transfer is important to the determination of turbine longevity, engine performance, and developmental costs. The need for accurate predictions will become greater as the operating temperatures and stage loading levels of advanced turbine engines increase. The present methods for predicting transition shear stress and heat transfer on turbine blades are based on incomplete knowledge and are largely empirical. To meet the objective of the NASA program, a team approach consisting of researchers from government, universities, a research institute, and a small business is presented. The research is divided into the areas of experiments, direct numerical simulations (DNS), and turbulence modeling. A summary of the results to date is given for the above research areas in a high-disturbance environment (bypass transition) with a discussion of the model development necessary for use in numerical codes.

Microfog lubricant application system for advanced turbine engine components, phase 3. [wetting characteristics and deposit forming tendencies of lubricants

NASA Technical Reports Server (NTRS)

Petrucco, R. J.; Leonardi, S. J.

1973-01-01

The wetting characteristics and deposit forming tendencies of a series of lubricants were evaluated using a microfog jet delivery system to wet a flat heated rotating disc. The performances of the nine lubricants are discussed in terms of the various testing parameters which include temperature, disc speed and lubricant gas flow rates. Also discussed are the heat transfer characteristics of two of the lubricants on that same plane disc specimen. The wetting characteristics and heat transfer characteristics of one of the lubricants on a complex disc simulating bearing geometry are also discussed.

Improving the engineering-and-economical performance of ore-thermal electric furnaces in the smelting of silicomanganese

NASA Astrophysics Data System (ADS)

Kondrashov, V. P.; Pogrebisskiy, M. Ya; Lykov, A. G.; Rabinovich, V. L.; Bulgakov, A. S.

2018-02-01

Ways of increase of ore-heating electric furnaces, used for production of silicomanganese, engineering-and-economical performance are analyzed. Questions of data of the electric, thermal and technological modes of the furnace functioning collecting and processing for use in operation of an advanced control system of the furnace providing increase in technical and economic efficiency of technological process and an adaptability to quality of burden stock are considered.

Ceramic Parts for Turbines

NASA Technical Reports Server (NTRS)

Jones, R. D.; Carpenter, Harry W.; Tellier, Jim; Rollins, Clark; Stormo, Jerry

1987-01-01

Abilities of ceramics to serve as turbine blades, stator vanes, and other elements in hot-gas flow of rocket engines discussed in report. Ceramics prime candidates, because of resistance to heat, low density, and tolerance of hostile environments. Ceramics considered in report are silicon nitride, silicon carbide, and new generation of such ceramic composites as transformation-toughened zirconia and alumina and particulate- or whisker-reinforced matrices. Report predicts properly designed ceramic components viable in advanced high-temperature rocket engines and recommends future work.

Shaping metallic glasses by electromagnetic pulsing

PubMed Central

Kaltenboeck, Georg; Demetriou, Marios D.; Roberts, Scott; Johnson, William L.

2016-01-01

With damage tolerance rivalling advanced engineering alloys and thermoplastic forming capabilities analogous to conventional plastics, metallic glasses are emerging as a modern engineering material. Here, we take advantage of their unique electrical and rheological properties along with the classic Lorentz force concept to demonstrate that electromagnetic coupling of electric current and a magnetic field can thermoplastically shape a metallic glass without conventional heating sources or applied mechanical forces. Specifically, we identify a process window where application of an electric current pulse in the presence of a normally directed magnetic field can ohmically heat a metallic glass to a softened state, while simultaneously inducing a large enough magnetic body force to plastically shape it. The heating and shaping is performed on millisecond timescales, effectively bypassing crystallization producing fully amorphous-shaped parts. This electromagnetic forming approach lays the groundwork for a versatile, time- and energy-efficient manufacturing platform for ultrastrong metals. PMID:26853460

Turbulence radiation coupling in boundary layers of heavy-duty diesel engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sircar, Arpan; Paul, Chandan; Ferreyro-Fernandez, Sebastian

The lack of accurate submodels for in-cylinder radiation and heat transfer has been identified as a key shortcoming in developing truly predictive, physics-based computational fluid dynamics (CFD) models that can be used to develop combustion systems for advanced high-efficiency, low-emissions engines. Recent measurements of wall layers in engines show discrepancies of up to 100% with respect to standard CFD boundary-layer models. And recent analysis of in-cylinder radiation based on the most recent spectral property databases and high-fidelity radiative transfer equation (RTE) solvers has shown that at operating pressures and exhaust-gas recirculation levels typical of modern heavy-duty compression-ignition engines, radiative emissionmore » can be as high as 40% of the wall heat losses, that molecular gas radiation (mainly CO2 and H2O) can be more important than soot radiation, and that a significant fraction of the emitted radiation can be reabsorbed before reaching the walls. That is, radiation not only contributes to heat losses, but also changes the in-cylinder temperature distribution, which in turn affects combustion and emissions. The goal of this research is to develop models that explicitly account for the potentially strong coupling between radiative and turbulent boundary layer heat transfer. For example, for optically thick conditions, a simple diffusion model might be formulated in terms of an absorption-coefficient-dependent turbulent Prandtl number.« less

Thermal Gradient Cyclic Behavior of a Thermal/Environmental Barrier Coating System on SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Lee, Kang N.; Miller, Robert A.

2002-01-01

Thermal barrier and environmental barrier coatings (TBCs and EBCs) will play a crucial role in future advanced gas turbine engines because of their ability to significantly extend the temperature capability of the ceramic matrix composite (CMC) engine components in harsh combustion environments. In order to develop high performance, robust coating systems for effective thermal and environmental protection of the engine components, appropriate test approaches for evaluating the critical coating properties must be established. In this paper, a laser high-heat-flux, thermal gradient approach for testing the coatings will be described. Thermal cyclic behavior of plasma-sprayed coating systems, consisting of ZrO2-8wt%Y2O3 thermal barrier and NASA Enabling Propulsion Materials (EPM) Program developed mullite+BSAS/Si type environmental barrier coatings on SiC/SiC ceramic matrix composites, was investigated under thermal gradients using the laser heat-flux rig in conjunction with the furnace thermal cyclic tests in water-vapor environments. The coating sintering and interface damage were assessed by monitoring the real-time thermal conductivity changes during the laser heat-flux tests and by examining the microstructural changes after the tests. The coating failure mechanisms are discussed based on the cyclic test results and are correlated to the sintering, creep, and thermal stress behavior under simulated engine temperature and heat flux conditions.

Similarity constraints in testing of cooled engine parts

NASA Technical Reports Server (NTRS)

Colladay, R. S.; Stepka, F. S.

1974-01-01

A study is made of the effect of testing cooled parts of current and advanced gas turbine engines at the reduced temperature and pressure conditions which maintain similarity with the engine environment. Some of the problems facing the experimentalist in evaluating heat transfer and aerodynamic performance when hardware is tested at conditions other than the actual engine environment are considered. Low temperature and pressure test environments can simulate the performance of actual size prototype engine hardware within the tolerance of experimental accuracy if appropriate similarity conditions are satisfied. Failure to adhere to these similarity constraints because of test facility limitations or other reasons, can result in a number of serious errors in projecting the performance of test hardware to engine conditions.

The ARIES Advanced and Conservative Tokamak Power Plant Study

DOE PAGES

Kessel, C. E; Tillak, M. S; Najmabadi, F.; ...

2015-12-22

Tokamak power plants are studied with advanced and conservative design philosophies to identify the impacts on the resulting designs and to provide guidance to critical research needs. Incorporating updated physics understanding and using more sophisticated engineering and physics analysis, the tokamak configurations have developed a more credible basis compared with older studies. The advanced configuration assumes a self-cooled lead lithium blanket concept with SiC composite structural material with 58% thermal conversion efficiency. This plasma has a major radius of 6.25 m, a toroidal field of 6.0 T, a q₉₅ of 4.5, aᵦ total N of 5.75, an H98 of 1.65,more » an n/n Gr of 1.0, and a peak divertor heat flux of 13.7 MW/m² . The conservative configuration assumes a dual-coolant lead lithium blanket concept with reduced activation ferritic martensitic steel structural material and helium coolant, achieving a thermal conversion efficiency of 45%. The plasma has a major radius of 9.75 m, a toroidal field of 8.75 T, a q₉₅ of 8.0, aᵦ total N of 2.5, an H₉₈ of 1.25, an n/n Gr of 1.3, and a peak divertor heat flux of 10 MW/m² . The divertor heat flux treatment with a narrow power scrape off width has driven the plasmas to larger major radius. Edge and divertor plasma simulations are targeting a basis for high radiated power fraction in the divertor, which is necessary for solutions to keep the peak heat flux in the range 10 to 15 MW/m² . Combinations of the advanced and conservative approaches show intermediate sizes. A new systems code using a database approach has been used and shows that the operating point is really an operating zone with some range of plasma and engineering parameters and very similar costs of electricity. Other papers in this issue provide more detailed discussion of the work summarized here.« less

The ARIES Advanced And Conservative Tokamak (ACT) Power Plant Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kessel, C. E.; Poli, F. M.; Ghantous, K.

2014-03-05

Tokamak power plants are studied with advanced and conservative design philosophies in order to identify the impacts on the resulting designs and to provide guidance to critical research needs. Incorporating updated physics understanding, and using more sophisticated engineering and physics analysis, the tokamak configurations have developed a more credible basis compared to older studies. The advanced configuration assumes a self-cooled lead lithium (SCLL) blanket concept with SiC composite structural material with 58% thermal conversion efficiency. This plasma has a major radius of 6.25 m, a toroidal field of 6.0 T, a q95 of 4.5, a βN total of 5.75, Hmore » 98 of 1.65, n/nGr of 1.0, and peak divertor heat flux of 13.7 MW/m 2. The conservative configuration assumes a dual coolant lead lithium (DCLL) blanket concept with ferritic steel structural material and helium coolant, achieving a thermal conversion efficiency of 45%. The plasma major radius is 9.75 m, a toroidal field of 8.75 T, a q95 of 8.0, a βN total of 2.5, H 98 of 1.25, n/n Gr of 1.3, and peak divertor heat flux of 10 MW/m 2. The divertor heat flux treatment with a narrow power scrape-off width has driven the plasmas to larger major radius. Edge and divertor plasma simulations are targeting a basis for high radiated power fraction in the divertor, which is necessary for solutions to keep the peak heat flux in the range of 10-15 MW/m 2. Combinations of the advanced and conservative approaches show intermediate sizes. A new systems code using a database approach has been used and shows that the operating point is really an operating zone with some range of plasma and engineering parameters and very similar costs of electricity. Papers in this issue provide more detailed discussion of the work summarized here.« less

Preliminary base heating environments for a generalized ALS LO2/LH2 launch vehicle, appendix 1 and 2

NASA Technical Reports Server (NTRS)

Bender, Robert L.; Reardon, John E.

1989-01-01

A secondary objective of contract NAS8-39141 is to provide base heating assessments, as required, to support Advanced Launch System (ALS) preliminary launch vehicle and propulsion system design studies. The ALS propulsion systems integration working group meeting (No. 3) recently completed in San Diego, California, focused attention on the need for base heating environment determination to provide preliminary requirements for LO2/LH2 propulsion systems currently being considered for ALS. We were requested to provide these environments for a range of possible propellant mixture and nozzle area ratios. Base heating environments can only be determined as a function of altitude when the engine operating conditions and vehicle base region geometry (engine arrangement) are known. If time dependent environments are needed to assess thermal loads, a trajectory must also be provided. These parameters are not fixed at this time since the ALS configurations and propulsion operating conditions are varied and continue to be studied by Phase B contractors. Therefore, for this study, a generalized LO2/LH2 system was selected along with a vehicle configuration consisting of a seven-engine booster and a three-engine core. MSFC provided guidance for the selection. We also selected a limited number of body points on the booster and core vehicles and engines for the environment estimates. Environments at these locations are representative of maximum heating conditions in the base region and are provided as a function of altitude only. Guidelines and assumptions for this assessment, methodology for determining the environments, and preliminary results are provided in this technical note. Refinements in the environments will be provided as the ALS design matures.

Radiative Heat Transfer and Turbulence-Radiation Interactions in a Heavy-Duty Diesel Engine

NASA Astrophysics Data System (ADS)

Paul, C.; Sircar, A.; Ferreyro, S.; Imren, A.; Haworth, D. C.; Roy, S.; Ge, W.; Modest, M. F.

2016-11-01

Radiation in piston engines has received relatively little attention to date. Recently, it is being revisited in light of current trends towards higher operating pressures and higher levels of exhaust-gas recirculation, both of which enhance molecular gas radiation. Advanced high-efficiency engines also are expected to function closer to the limits of stable operation, where even small perturbations to the energy balance can have a large influence on system behavior. Here several different spectral radiation property models and radiative transfer equation (RTE) solvers have been implemented in an OpenFOAM-based engine CFD code, and simulations have been performed for a heavy-duty diesel engine. Differences in computed temperature fields, NO and soot levels, and wall heat transfer rates are shown for different combinations of spectral models and RTE solvers. The relative importance of molecular gas radiation versus soot radiation is examined. And the influence of turbulence-radiation interactions is determined by comparing results obtained using local mean values of composition and temperature to compute radiative emission and absorption with those obtained using a particle-based transported probability density function method. DOE, NSF.

Radiative Heat Transfer modelling in a Heavy-Duty Diesel Engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul, Chandan; Sircar, Arpan; Ferreyro-Fernandez, Sebastian

Detailed radiation modelling in piston engines has received relatively little attention to date. Recently, it is being revisited in light of current trends towards higher operating pressures and higher levels of exhaust-gas recirculation, both of which enhance molecular gas radiation. Advanced high-efficiency engines also are expected to function closer to the limits of stable operation, where even small perturbations to the energy balance can have a large influence on system behavior. Here several different spectral radiation property models and radiative transfer equation (RTE) solvers have been implemented in an OpenFOAM-based engine CFD code, and simulations have been performed for amore » heavy-duty diesel engine. Differences in computed temperature fields, NO and soot levels, and wall heat transfer rates are shown for different combinations of spectral models and RTE solvers. The relative importance of molecular gas radiation versus soot radiation is examined. And the influence of turbulence-radiation interactions is determined by comparing results obtained using local mean values of composition and temperature to compute radiative emission and absorption with those obtained using a particle-based transported probability density function method.« less

Research Proposal for the Design and Engineering Phase of a Solar Heating and Cooling System Experiment at the Warner Robins Public Library, Warner Robins, Georgia. Submitted to the United States Energy Research and Development Administration.

ERIC Educational Resources Information Center

Phillips, Warren H.; And Others

A number of reasons are advanced to include a solar heating and cooling experiment in a library building. The unique aspects of the experiment are to be a seasonally adjustable collector tilt and testing of a new generation of absorption air conditioners. After a brief description of the proposed experiment, the proposal contains forms filed by…

Heavy Duty Roots Expander Heat Energy Recovery (HD-REHER)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Subramanian, Swami

2015-10-01

Eaton Corporation proposed a comprehensive project to develop and demonstrate advanced component technology that will reduce the cost of implementing Organic Rankine Cycle (ORC) Waste Heat Recovery (WHR) systems to Heavy-Duty Diesel engines, making adaptation of this fuel efficiency improving technology more commercially attractive to end-users in the next 5 to 10 year time period. Accelerated adaptation and implementation of new fuel efficiency technology into service is critical for reduction of fuel used in the commercial vehicle segment.

Advanced Divertor Design and Application under Modern Superconducting Tokamak Constraints

NASA Astrophysics Data System (ADS)

Covele, Brent; Kotschenreuther, Mike; Mahajan, Swadesh; Valanju, Prashant

2013-10-01

With current ITER projections already predicting divertor exhaust heat loads in the 5-10 MW/m2 range, i.e. at the maximum tolerance, it is clear that the divertor heat load problem will only be exacerbated for future superconducting tokamaks, as well as perhaps some modern tokamaks today. Thus, an advanced divertor, such as the X-Divertor (XD), Super-X Divertor (SXD), or Snowflake (SF) will become a virtual necessity to reduce incident heat flux at the target plates. Using the 2D magnetic equilibrium code CORSICA, we explore the possibilities of creating an advanced divertor for a next-generation superconducting tokamak (Ip = 15 MA, BT = 5.3 T, R = 6.2 m) under nominal engineering constraints. Advanced divertors were achieved with no in-vessel PF coils, PF current densities below 30 MA/m2, and vertical maintenance access, all of which are favorable conditions for tokamaks today. Both the XD and SF divertors are readily achievable while maintaining core plasma performance, and the advantages and disadvantages of each are discussed in turn. Some thought is given as to how the divertor cassette will need to be modified to accommodate advanced divertors. Work supported under US-DOE projects DE-FG02-04ER54742 and DE-FG02-04ER54754.

Conduction-driven cooling of LED-based automotive LED lighting systems for abating local hot spots

NASA Astrophysics Data System (ADS)

Saati, Ferina; Arik, Mehmet

2018-02-01

Light-emitting diode (LED)-based automotive lighting systems pose unique challenges, such as dual-side packaging (front side for LEDs and back side for driver electronics circuit), size, harsh ambient, and cooling. Packaging for automotive lighting applications combining the advanced printed circuit board (PCB) technology with a multifunctional LED-based board is investigated with a focus on the effect of thermal conduction-based cooling for hot spot abatement. A baseline study with a flame retardant 4 technology, commonly known as FR4 PCB, is first compared with a metal-core PCB technology, both experimentally and computationally. The double-sided advanced PCB that houses both electronics and LEDs is then investigated computationally and experimentally compared with the baseline FR4 PCB. Computational models are first developed with a commercial computational fluid dynamics software and are followed by an advanced PCB technology based on embedded heat pipes, which is computationally and experimentally studied. Then, attention is turned to studying different heat pipe orientations and heat pipe placements on the board. Results show that conventional FR4-based light engines experience local hot spots (ΔT>50°C) while advanced PCB technology based on heat pipes and thermal spreaders eliminates these local hot spots (ΔT<10°C), leading to a higher lumen extraction with improved reliability. Finally, possible design options are presented with embedded heat pipe structures that further improve the PCB performance.

Convective Heat Transfer with and without Film Cooling in High Temperature, Fuel Rich and Lean Environments

NASA Astrophysics Data System (ADS)

Greiner, Nathan J.

Modern turbine engines require high turbine inlet temperatures and pressures to maximize thermal efficiency. Increasing the turbine inlet temperature drives higher heat loads on the turbine surfaces. In addition, increasing pressure ratio increases the turbine coolant temperature such that the ability to remove heat decreases. As a result, highly effective external film cooling is required to reduce the heat transfer to turbine surfaces. Testing of film cooling on engine hardware at engine temperatures and pressures can be exceedingly difficult and expensive. Thus, modern studies of film cooling are often performed at near ambient conditions. However, these studies are missing an important aspect in their characterization of film cooling effectiveness. Namely, they do not model effect of thermal property variations that occur within the boundary and film cooling layers at engine conditions. Also, turbine surfaces can experience significant radiative heat transfer that is not trivial to estimate analytically. The present research first computationally examines the effect of large temperature variations on a turbulent boundary layer. Subsequently, a method to model the effect of large temperature variations within a turbulent boundary layer in an environment coupled with significant radiative heat transfer is proposed and experimentally validated. Next, a method to scale turbine cooling from ambient to engine conditions via non-dimensional matching is developed computationally and the experimentally validated at combustion temperatures. Increasing engine efficiency and thrust to weight ratio demands have driven increased combustor fuel-air ratios. Increased fuel-air ratios increase the possibility of unburned fuel species entering the turbine. Alternatively, advanced ultra-compact combustor designs have been proposed to decrease combustor length, increase thrust, or generate power for directed energy weapons. However, the ultra-compact combustor design requires a film cooled vane within the combustor. In both these environments, the unburned fuel in the core flow encounters the oxidizer rich film cooling stream, combusts, and can locally heat the turbine surface rather than the intended cooling of the surface. Accordingly, a method to quantify film cooling performance in a fuel rich environment is prescribed. Finally, a method to film cool in a fuel rich environment is experimentally demonstrated.

Overview of NASA Glenn Research Center Programs in Aero-Heat Transfer and Future Needs

NASA Technical Reports Server (NTRS)

Gaugler, Raymond E.

2002-01-01

This presentation concentrates on an overview of the NASA Glenn Research Center and the projects that are supporting Turbine Aero-Heat Transfer Research. The principal areas include the Ultra Efficient Engine Technology (UEET) Project, the Advanced Space Transportation Program (ASTP) Revolutionary Turbine Accelerator (RTA) Turbine Based Combined Cycle (TBCC) project, and the Propulsion & Power Base R&T - Smart Efficient Components (SEC), and Revolutionary Aeropropulsion Concepts (RAC) Projects. In addition, highlights are presented of the turbine aero-heat transfer work currently underway at NASA Glenn, focusing on the use of the Glenn-HT Navier- Stokes code as the vehicle for research in turbulence & transition modeling, grid topology generation, unsteady effects, and conjugate heat transfer.

Experimental study of heating scheme effect on the inner divertor power footprint widths in EAST lower single null discharges

NASA Astrophysics Data System (ADS)

Deng, G. Z.; Xu, J. C.; Liu, X.; Liu, X. J.; Liu, J. B.; Zhang, H.; Liu, S. C.; Chen, L.; Yan, N.; Feng, W.; Liu, H.; Xia, T. Y.; Zhang, B.; Shao, L. M.; Ming, T. F.; Xu, G. S.; Guo, H. Y.; Xu, X. Q.; Gao, X.; Wang, L.

2018-04-01

A comprehensive work of the effects of plasma current and heating schemes on divertor power footprint widths is carried out in the experimental advanced superconducting tokamak (EAST). The divertor power footprint widths, i.e., the scrape-off layer heat flux decay length λ q and the heat spreading S, are crucial physical and engineering parameters for fusion reactors. Strong inverse scaling of λ q and S with plasma current have been demonstrated for both neutral beam (NB) and lower hybrid wave (LHW) heated L-mode and H-mode plasmas at the inner divertor target. For plasmas heated by the combination of the two kinds of auxiliary heating schemes (NB and LHW), the divertor power widths tend to be larger in plasmas with higher ratio of LHW power. Comparison between experimental heat flux profiles at outer mid-plane (OMP) and divertor target for NB heated and LHW heated L-mode plasmas reveals that the magnetic topology changes induced by LHW may be the main reason to the wider divertor power widths in LHW heated discharges. The effect of heating schemes on divertor peak heat flux has also been investigated, and it is found that LHW heated discharges tend to have a lower divertor peak heat flux compared with NB heated discharges under similar input power. All these findings seem to suggest that plasmas with LHW auxiliary heating scheme are better heat exhaust scenarios for fusion reactors and should be the priorities for the design of next-step fusion reactors like China Fusion Engineering Test Reactor.

Development of Mechanics in Support of Rocket Technology in Ukraine

NASA Astrophysics Data System (ADS)

Prisnyakov, Vladimir

2003-06-01

The paper analyzes the advances of mechanics made in Ukraine in resolving various problems of space and rocket technology such as dynamics and strength of rockets and rocket engines, rockets of different purpose, electric rocket engines, and nonstationary processes in various systems of rockets accompanied by phase transitions of working media. Achievements in research on the effect of vibrations and gravitational fields on the behavior of space-rocket systems are also addressed. Results obtained in investigating the reliability and structural strength durability conditions for nuclear installations, solid- and liquid-propellant engines, and heat pipes are presented

Leakage and Power Loss Test Results for Competing Turbine Engine Seals

NASA Technical Reports Server (NTRS)

Proctor, Margaret P.; Delgado, Irebert R.

2004-01-01

Advanced brush and finger seal technologies offer reduced leakage rates over conventional labyrinth seals used in gas turbine engines. To address engine manufacturers concerns about the heat generation and power loss from these contacting seals, brush, finger, and labyrinth seals were tested in the NASA High Speed, High Temperature Turbine Seal Test Rig. Leakage and power loss test results are compared for these competing seals for operating conditions up to 922 K (1200 F) inlet air temperature, 517 KPa (75 psid) across the seal, and surface velocities up to 366 m/s (1200 ft/s).

Projected techno-economic improvements for advanced solar thermal power plants

NASA Technical Reports Server (NTRS)

Fujita, T.; Manvi, R.; Roschke, E. J.

1979-01-01

The projected characteristics of solar thermal power plants (with outputs up to 10 MWe) employing promising advanced technology subsystems/components are compared to current (or pre-1985) steam-Rankine systems. Improvements accruing to advanced technology development options are delineated. The improvements derived from advanced systems result primarily from achieving high efficiencies via solar collector systems which (1) capture a large portion of the available insolation and (2) concentrate this captured solar flux to attain high temperatures required for high heat engine/energy conversion performance. The most efficient solar collector systems employ two-axis tracking. Attractive systems include the central receiver/heliostat and the parabolic dish.

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1989-01-01

ATTAP activities during the past year were highlighted by an extensive materials assessment, execution of a reference powertrain design, test-bed engine design and development, ceramic component design, materials and component characterization, ceramic component process development and fabrication, component rig design and fabrication, test-bed engine fabrication, and hot gasifier rig and engine testing. Materials assessment activities entailed engine environment evaluation of domestically supplied radial gasifier turbine rotors that were available at the conclusion of the Advanced Gas Turbine (AGT) Technology Development Project as well as an extensive survey of both domestic and foreign ceramic suppliers and Government laboratories performing ceramic materials research applicable to advanced heat engines. A reference powertrain design was executed to reflect the selection of the AGT-5 as the ceramic component test-bed engine for the ATTAP. Test-bed engine development activity focused on upgrading the AGT-5 from a 1038 C (1900 F) metal engine to a durable 1371 C (2500 F) structural ceramic component test-bed engine. Ceramic component design activities included the combustor, gasifier turbine static structure, and gasifier turbine rotor. The materials and component characterization efforts have included the testing and evaluation of several candidate ceramic materials and components being developed for use in the ATTAP. Ceramic component process development and fabrication activities were initiated for the gasifier turbine rotor, gasifier turbine vanes, gasifier turbine scroll, extruded regenerator disks, and thermal insulation. Component rig development activities included combustor, hot gasifier, and regenerator rigs. Test-bed engine fabrication activities consisted of the fabrication of an all-new AGT-5 durability test-bed engine and support of all engine test activities through instrumentation/build/repair. Hot gasifier rig and test-bed engine testing activities were performed.

DROPWISE CONDENSATION ON MICRO- AND NANOSTRUCTURED SURFACES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Enright, R; Miljkovic, N; Alvarado, JL

In this review we cover recent developments in the area of surface-enhanced dropwise condensation against the background of earlier work. The development of fabrication techniques to create surface structures at the micro-and nanoscale using both bottom-up and top-down approaches has led to increased study of complex interfacial phenomena. In the heat transfer community, researchers have been extensively exploring the use of advanced surface structuring techniques to enhance phase-change heat transfer processes. In particular, the field of vapor-to-liquid condensation and especially that of water condensation has experienced a renaissance due to the promise of further optimizing this process at the micro-andmore » nanoscale by exploiting advances in surface engineering developed over the last several decades.« less

Toward an Improved Hypersonic Engine Seal

NASA Technical Reports Server (NTRS)

Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; DeMange,Jeffrey J.; Taylor, Shawn C.

2003-01-01

High temperature, dynamic seals are required in advanced engines to seal the perimeters of movable engine ramps for efficient, safe operation in high heat flux environments at temperatures from 2000 to 2500 F. Current seal designs do not meet the demanding requirements for future engines, so NASA s Glenn Research Center (GRC) is developing advanced seals to overcome these shortfalls. Two seal designs and two types of seal preloading devices were evaluated in a series of compression tests at room temperature and 2000 F and flow tests at room temperature. Both seals lost resiliency with repeated load cycling at room temperature and 2000 F, but seals with braided cores were significantly more flexible than those with cores composed of uniaxial ceramic fibers. Flow rates for the seals with cores of uniaxial fibers were lower than those for the seals with braided cores. Canted coil springs and silicon nitride compression springs showed promise conceptually as potential seal preloading devices to help maintain seal resiliency.

AGT (Advanced Gas Turbine) technology project

NASA Technical Reports Server (NTRS)

1988-01-01

An overall summary documentation is provided for the Advanced Gas Turbine Technology Project conducted by the Allison Gas Turbine Division of General Motors. This advanced, high risk work was initiated in October 1979 under charter from the U.S. Congress to promote an engine for transportation that would provide an alternate to reciprocating spark ignition (SI) engines for the U.S. automotive industry and simultaneously establish the feasibility of advanced ceramic materials for hot section components to be used in an automotive gas turbine. As this program evolved, dictates of available funding, Government charter, and technical developments caused program emphases to focus on the development and demonstration of the ceramic turbine hot section and away from the development of engine and powertrain technologies and subsequent vehicular demonstrations. Program technical performance concluded in June 1987. The AGT 100 program successfully achieved project objectives with significant technology advances. Specific AGT 100 program achievements are: (1) Ceramic component feasibility for use in gas turbine engines has been demonstrated; (2) A new, 100 hp engine was designed, fabricated, and tested for 572 hour at operating temperatures to 2200 F, uncooled; (3) Statistical design methodology has been applied and correlated to experimental data acquired from over 5500 hour of rig and engine testing; (4) Ceramic component processing capability has progressed from a rudimentary level able to fabricate simple parts to a sophisticated level able to provide complex geometries such as rotors and scrolls; (5) Required improvements for monolithic and composite ceramic gas turbine components to meet automotive reliability, performance, and cost goals have been identified; (6) The combustor design demonstrated lower emissions than 1986 Federal Standards on methanol, JP-5, and diesel fuel. Thus, the potential for meeting emission standards and multifuel capability has been initiated; (7) Small turbine engine aerodynamic and mechanical design capability has been initiated; and (8) An infrastructure of manpower, facilities, materials, and fabrication capabilities has been established which is available for continued development of ceramic component technology in gas turbine and other heat engines.

Research on EHN additive on the diesel engine combustion characteristics in plateau environment

NASA Astrophysics Data System (ADS)

Sun, Zhixin; Li, Ruoting; Wang, Xiancheng; Hu, Chuan

2017-03-01

Aiming at the combustion deterioration problem of diesel engine in plateau environment, a bench test was carried out for the effects of EHN additive on combustion characteristics of the diesel engine with intake pressure of 0.68 kPa. Test results showed that with the full load working condition of 1 400 r/min: Cylinder pressure and pressure uprising rate decreased with EHN additive added in, mechanical load on the engine could be relieved; peak value of the heat release rate decreased and its occurrence advanced, ignition delay and combustion duration were shortened; cylinder temperature and exhaust gas temperature declined, thermal load on the engine could be relieved, output torque increased while specific oil consumption decreased, and effective thermal efficiency of diesel engine increased.

Intelligent Engine Systems: HPT Clearance Control

NASA Technical Reports Server (NTRS)

2008-01-01

The Advanced Thermally Actuated Clearance Control System underwent several studies. Improved flow path isolation quantified what can be gained by making the HPT case nearly adiabatic. The best method of heat transfer was established, and finally two different borrowed air cooling circuits were evaluated to be used for the HPT Active Clearance Control System.

Advances in Integrated Computational Materials Engineering "ICME"

NASA Astrophysics Data System (ADS)

Hirsch, Jürgen

The methods of Integrated Computational Materials Engineering that were developed and successfully applied for Aluminium have been constantly improved. The main aspects and recent advances of integrated material and process modeling are simulations of material properties like strength and forming properties and for the specific microstructure evolution during processing (rolling, extrusion, annealing) under the influence of material constitution and process variations through the production process down to the final application. Examples are discussed for the through-process simulation of microstructures and related properties of Aluminium sheet, including DC ingot casting, pre-heating and homogenization, hot and cold rolling, final annealing. New results are included of simulation solution annealing and age hardening of 6xxx alloys for automotive applications. Physically based quantitative descriptions and computer assisted evaluation methods are new ICME methods of integrating new simulation tools also for customer applications, like heat affected zones in welding of age hardening alloys. The aspects of estimating the effect of specific elements due to growing recycling volumes requested also for high end Aluminium products are also discussed, being of special interest in the Aluminium producing industries.

USAF Advanced Terrestrial Energy Study. Volume 4. Analysis, Data, and Bibliography.

DTIC Science & Technology

1983-04-01

OBJECTIVE OF THIS PROGRAM IS T0 DEVELOP A METHODOLOGY FOR PREDICTING LON(.o-TERM FUEL CELL PERFORM4ANCE FROM S"ORT-TEIM VESTING. APPLYING THE PERVURbATION...ION PROGRAM WAS DEVELOPED FOR ACTUALLY INSTALLINGP THE FUEL CELL POWER PLANT AT THE SANTA CLARA SIE DE SCh1PT ORS6 AIR POLLUTION DATtMENT;AUXILIARY...IV OF THE CERAMIC TECHNOLUGY READINESS PROGRAM TITL IMDNU) ADVANCED MATER IALS FUR ALTERNATIVE FUEL CAPABLE DIRECTLY FIRED HEAT ENGINES 36 - - - . r

Low Conductivity Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming

2005-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. In this presentation, thermal barrier coating development considerations and requirements will be discussed. An experimental approach is established to monitor in real time the thermal conductivity of the coating systems subjected to high-heat-flux, steady-state and cyclic temperature gradients. Advanced low conductivity thermal barrier coatings have also been developed using a multi-component defect clustering approach, and shown to have improved thermal stability. The durability and erosion resistance of low conductivity thermal barrier coatings have been improved utilizing advanced coating architecture design, composition optimization, in conjunction with more sophisticated modeling and design tools.

Heat pump system

DOEpatents

Swenson, Paul F.; Moore, Paul B.

1979-01-01

An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchangers and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

Heat pump system

DOEpatents

Swenson, Paul F.; Moore, Paul B.

1982-01-01

An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchanges and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

Thin Film Heat Flux Sensor Development for Ceramic Matrix Composite (CMC) Systems

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Fralick, Gustave C.; Hunter, Gary W.; Zhu, Dongming; Laster, Kimala L.; Gonzalez, Jose M.; Gregory, Otto J.

2010-01-01

The NASA Glenn Research Center (GRC) has an on-going effort for developing high temperature thin film sensors for advanced turbine engine components. Stable, high temperature thin film ceramic thermocouples have been demonstrated in the lab, and novel methods of fabricating sensors have been developed. To fabricate thin film heat flux sensors for Ceramic Matrix Composite (CMC) systems, the rough and porous nature of the CMC system posed a significant challenge for patterning the fine features required. The status of the effort to develop thin film heat flux sensors specifically for use on silicon carbide (SiC) CMC systems with these new technologies is described.

Combustion Dynamics and Control for Ultra Low Emissions in Aircraft Gas-Turbine Engines

NASA Technical Reports Server (NTRS)

DeLaat, John C.

2011-01-01

Future aircraft engines must provide ultra-low emissions and high efficiency at low cost while maintaining the reliability and operability of present day engines. The demands for increased performance and decreased emissions have resulted in advanced combustor designs that are critically dependent on efficient fuel/air mixing and lean operation. However, all combustors, but most notably lean-burning low-emissions combustors, are susceptible to combustion instabilities. These instabilities are typically caused by the interaction of the fluctuating heat release of the combustion process with naturally occurring acoustic resonances. These interactions can produce large pressure oscillations within the combustor and can reduce component life and potentially lead to premature mechanical failures. Active Combustion Control which consists of feedback-based control of the fuel-air mixing process can provide an approach to achieving acceptable combustor dynamic behavior while minimizing emissions, and thus can provide flexibility during the combustor design process. The NASA Glenn Active Combustion Control Technology activity aims to demonstrate active control in a realistic environment relevant to aircraft engines by providing experiments tied to aircraft gas turbine combustors. The intent is to allow the technology maturity of active combustion control to advance to eventual demonstration in an engine environment. Work at NASA Glenn has shown that active combustion control, utilizing advanced algorithms working through high frequency fuel actuation, can effectively suppress instabilities in a combustor which emulates the instabilities found in an aircraft gas turbine engine. Current efforts are aimed at extending these active control technologies to advanced ultra-low-emissions combustors such as those employing multi-point lean direct injection.

A Heat Transfer Investigation of Liquid and Two-Phase Methane

NASA Technical Reports Server (NTRS)

VanNoord, Jonathan

2010-01-01

A heat transfer investigation was conducted for liquid and two-phase methane. The tests were conducted at the NASA Glenn Research Center Heated Tube Facility (HTF) using resistively heated tube sections to simulate conditions encountered in regeneratively cooled rocket engines. This testing is part of NASA s Propulsion and Cryogenics Advanced Development (PCAD) project. Nontoxic propellants, such as liquid oxygen/liquid methane (LO2/LCH4), offer potential benefits in both performance and safety over equivalently sized hypergolic propulsion systems in spacecraft applications. Regeneratively cooled thrust chambers are one solution for high performance, robust LO2/LCH4 engines, but cooling data on methane is limited. Several test runs were conducted using three different diameter Inconel 600 tubes, with nominal inner diameters of 0.0225-, 0.054-, and 0.075-in. The mass flow rate was varied from 0.005 to 0.07 lbm/sec. As the current focus of the PCAD project is on pressure fed engines for LO2/LCH4, the average test section outlet pressures were targeted to be 200 psia or 500 psia. The heat flux was incrementally increased for each test condition while the test section wall temperatures were monitored. A maximum average heat flux of 6.2 Btu/in.2 sec was achieved and, at times, the temperatures of the test sections reached in excess of 1800 R. The primary objective of the tests was to produce heat transfer correlations for methane in the liquid and two-phase regime. For two-phase flow testing, the critical heat flux values were determined where the fluid transitions from nucleate boiling to film boiling. A secondary goal of the testing was to measure system pressure drops in the two-phase regime.

Comparative evaluation of three alternative power cycles for waste heat recovery from the exhaust of adiabatic diesel engines

NASA Technical Reports Server (NTRS)

Bailey, M. M.

1985-01-01

Three alternative power cycles were compared in application as an exhaust-gas heat-recovery system for use with advanced adiabatic diesel engines. The power cycle alternatives considered were steam Rankine, organic Rankine with RC-1 as the working fluid, and variations of an air Brayton cycle. The comparison was made in terms of fuel economy and economic payback potential for heavy-duty trucks operating in line-haul service. The results indicate that, in terms of engine rated specific fuel consumption, a diesel/alternative-power-cycle engine offers a significant improvement over the turbocompound diesel used as the baseline for comparison. The maximum imporvement resulted from the use of a Rankine cycle heat-recovery system in series with turbocompounding. The air Brayton cycle alternatives studied, which included both simple-cycle and compression-intercooled configurations, were less effective and provided about half the fuel consumption improvement of the Rankine cycle alternatives under the same conditions. Capital and maintenance cost estimates were also developed for each of the heat-recovery power cycle systems. These costs were integrated with the fuel savings to identify the time required for net annual savings to pay back the initial capital investment. The sensitivity of capital payback time to arbitrary increases in fuel price, not accompanied by corresponding hardware cost inflation, was also examined. The results indicate that a fuel price increase is required for the alternative power cycles to pay back capital within an acceptable time period.

Microtube strip heat exchanger

NASA Astrophysics Data System (ADS)

Doty, F. D.

1992-07-01

The purpose of this contract has been to explore the limits of miniaturization of heat exchangers with the goals of (1) improving the theoretical understanding of laminar heat exchangers, (2) evaluating various manufacturing difficulties, and (3) identifying major applications for the technology. A low-cost, ultra-compact heat exchanger could have an enormous impact on industry in the areas of cryocoolers and energy conversion. Compact cryocoolers based on the reverse Brayton cycle (RBC) would become practical with the availability of compact heat exchangers. Many experts believe that hardware advances in personal computer technology will rapidly slow down in four to six years unless lowcost, portable cryocoolers suitable for the desktop supercomputer can be developed. Compact refrigeration systems would permit dramatic advances in high-performance computer work stations with 'conventional' microprocessors operating at 150 K, and especially with low-cost cryocoolers below 77 K. NASA has also expressed strong interest in our MTS exchanger for space-based RBC cryocoolers for sensor cooling. We have demonstrated feasibility of higher specific conductance by a factor of five than any other work in high-temperature gas-to-gas exchangers. These laminar-flow, microtube exchangers exhibit extremely low pressure drop compared to alternative compact designs under similar conditions because of their much shorter flow length and larger total flow area for lower flow velocities. The design appears to be amenable to mass production techniques, but considerable process development remains. The reduction in materials usage and the improved heat exchanger performance promise to be of enormous significance in advanced engine designs and in cryogenics.

Sodium Based Heat Pipe Modules for Space Reactor Concepts: Stainless Steel SAFE-100 Core

NASA Technical Reports Server (NTRS)

Martin, James J.; Reid, Robert S.

2004-01-01

A heat pipe cooled reactor is one of several candidate reactor cores being considered for advanced space power and propulsion systems to support future space exploration applications. Long life heat pipe modules, with designs verified through a combination of theoretical analysis and experimental lifetime evaluations, would be necessary to establish the viability of any of these candidates, including the heat pipe reactor option. A hardware-based program was initiated to establish the infrastructure necessary to build heat pipe modules. This effort, initiated by Los Alamos National Laboratory and referred to as the Safe Affordable Fission Engine (SAFE) project, set out to fabricate and perform non-nuclear testing on a modular heat pipe reactor prototype that can provide 100 kilowatt from the core to an energy conversion system at 700 C. Prototypic heat pipe hardware was designed, fabricated, filled, closed-out and acceptance tested.

Needs assessment for nondestructive testing and materials characterization for improved reliability in structural ceramics for heat engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, D.R.; McClung, R.W.; Janney, M.A.

1987-08-01

A needs assessment was performed for nondestructive testing and materials characterization to achieve improved reliability in ceramic materials for heat engine applications. Raw materials, green state bodies, and sintered ceramics were considered. The overall approach taken to improve reliability of structural ceramics requires key inspections throughout the fabrication flowsheet, including raw materials, greed state, and dense parts. The applications of nondestructive inspection and characterization techniques to ceramic powders and other raw materials, green ceramics, and sintered ceramics are discussed. The current state of inspection technology is reviewed for all identified attributes and stages of a generalized flowsheet for advanced structuralmore » ceramics, and research and development requirements are identified and listed in priority order. 164 refs., 3 figs.« less

A Research Program for Improving Heat Transfer Prediction Capability for the Laminar to Turbulent Transition Region of Turbine Vanes/Blades

NASA Technical Reports Server (NTRS)

Simon, Frederick F.

2007-01-01

A program sponsored by the National Aeronautics and Space Administration (NASA) for the investigation of the heat transfer in the transition region of turbine vanes and blades with the object of improving the capability for predicting heat transfer is described,. The accurate prediction of gas-side heat transfer is important to the determination of turbine longevity, engine performance and developmental costs. The need for accurate predictions will become greater as the operating temperatures and stage loading levels of advanced turbine engines increase. The present methods for predicting transition shear stress and heat transfer on turbine blades are based on incomplete knowledge and are largely empirical. To meet the objectives of the NASA program, a team approach consisting of researchers from government, universities, a research institute, and a small business is presented. The research is divided into areas of experimentation, direct numerical simulation (DNS) and turbulence modeling. A summary of the results to date is given for the above research areas in a high-disturbance environment (bypass transition) with a discussion of the model development necessary for use in numerical codes.

HOST turbine heat transfer program summary

NASA Technical Reports Server (NTRS)

Gladden, Herbert J.; Simoneau, Robert J.

1988-01-01

The objectives of the HOST Turbine Heat Transfer subproject were to obtain a better understanding of the physics of the aerothermodynamic phenomena and to assess and improve the analytical methods used to predict the flow and heat transfer in high temperature gas turbines. At the time the HOST project was initiated, an across-the-board improvement in turbine design technology was needed. A building-block approach was utilized and the research ranged from the study of fundamental phenomena and modeling to experiments in simulated real engine environments. Experimental research accounted for approximately 75 percent of the funding with the remainder going to analytical efforts. A healthy government/industry/university partnership, with industry providing almost half of the research, was created to advance the turbine heat transfer design technology base.

Performance and heat transfer characteristics of the laser-heated rocket - A future space transportation system

NASA Technical Reports Server (NTRS)

Shoji, J. M.; Larson, V. R.

1976-01-01

The application of advanced liquid-bipropellant rocket engine analysis techniques has been utilized for prediction of the potential delivered performance and the design of thruster wall cooling schemes for laser-heated rocket thrusters. Delivered specific impulse values greater than 1000 lbf-sec/lbm are potentially achievable based on calculations for thrusters designed for 10-kW and 5000-kW laser beam power levels. A thruster wall-cooling technique utilizing a combination of regenerative cooling and a carbon-seeded hydrogen boundary layer is presented. The flowing carbon-seeded hydrogen boundary layer provides radiation absorption of the heat radiated from the high-temperature plasma. Also described is a forced convection thruster wall cooling design for an experimental test thruster.

Advanced diesel engine component development program, tasks 4-14

NASA Astrophysics Data System (ADS)

Kaushal, Tony S.; Weber, Karen E.

1994-11-01

This report summarizes the Advanced Diesel Engine Component Development (ADECD) Program to develop and demonstrate critical technology needed to advance the heavy-duty low heat rejection engine concept. Major development activities reported are the design, analysis, and fabrication of monolithic ceramic components; vapor phase and solid film lubrication; electrohydraulic valve actuation; and high pressure common rail injection. An advanced single cylinder test bed was fabricated as a laboratory tool in studying these advanced technologies. This test bed simulates the reciprocator for a system having no cooling system, turbo compounding, Rankine bottoming cycle, common rail injection, and variable valve actuation to achieve fuel consumption of 160 g/kW-hr (.26 lb/hp-hr). The advanced concepts were successfully integrated into the test engine. All ceramic components met their functional and reliability requirements. The firedeck, cast-in-place ports, valves, valve guides, piston cap, and piston ring were made from silicon nitride. Breakthroughs required to implement a 'ceramic' engine included the fabrication of air-gap cylinder heads, elimination of compression gaskets, machining of ceramic valve seats within the ceramic firedeck, fabrication of cast-in-place ceramic port liners, implementation of vapor phase lubrication, and elimination of the engine coolant system. Silicon nitride valves were successfully developed to meet several production abuse test requirements and incorporated into the test bed with a ceramic valve guide and solid film lubrication. The ADECD cylinder head features ceramic port shields to increase insulation and exhaust energy recovery. The combustion chamber includes a ceramic firedeck and piston cap. The tribological challenge posed by top ring reversal temperatures of 550 C was met through the development of vapor phase lubrication using tricresyl phosphate at the ring-liner interface. A solenoid-controlled, variable valve actuation system that eliminated the conventional camshaft was demonstrated on the test bed. High pressure fuel injection via a common rail system was also developed to reduce particulate emissions.

Advanced diesel engine component development program, tasks 4-14

NASA Technical Reports Server (NTRS)

Kaushal, Tony S.; Weber, Karen E.

1994-01-01

This report summarizes the Advanced Diesel Engine Component Development (ADECD) Program to develop and demonstrate critical technology needed to advance the heavy-duty low heat rejection engine concept. Major development activities reported are the design, analysis, and fabrication of monolithic ceramic components; vapor phase and solid film lubrication; electrohydraulic valve actuation; and high pressure common rail injection. An advanced single cylinder test bed was fabricated as a laboratory tool in studying these advanced technologies. This test bed simulates the reciprocator for a system having no cooling system, turbo compounding, Rankine bottoming cycle, common rail injection, and variable valve actuation to achieve fuel consumption of 160 g/kW-hr (.26 lb/hp-hr). The advanced concepts were successfully integrated into the test engine. All ceramic components met their functional and reliability requirements. The firedeck, cast-in-place ports, valves, valve guides, piston cap, and piston ring were made from silicon nitride. Breakthroughs required to implement a 'ceramic' engine included the fabrication of air-gap cylinder heads, elimination of compression gaskets, machining of ceramic valve seats within the ceramic firedeck, fabrication of cast-in-place ceramic port liners, implementation of vapor phase lubrication, and elimination of the engine coolant system. Silicon nitride valves were successfully developed to meet several production abuse test requirements and incorporated into the test bed with a ceramic valve guide and solid film lubrication. The ADECD cylinder head features ceramic port shields to increase insulation and exhaust energy recovery. The combustion chamber includes a ceramic firedeck and piston cap. The tribological challenge posed by top ring reversal temperatures of 550 C was met through the development of vapor phase lubrication using tricresyl phosphate at the ring-liner interface. A solenoid-controlled, variable valve actuation system that eliminated the conventional camshaft was demonstrated on the test bed. High pressure fuel injection via a common rail system was also developed to reduce particulate emissions.

Development of Advanced Thermal and Environmental Barrier Coatings Using a High-Heat-Flux Testing Approach

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2003-01-01

The development of low conductivity, robust thermal and environmental barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity and cyclic resistance at very high surface temperatures (up to 1700 C) under large thermal gradients. In this study, a laser high-heat-flux test approach is established for evaluating advanced low conductivity, high temperature capability thermal and environmental barrier coatings under the NASA Ultra Efficient Engine Technology (UEET) program. The test approach emphasizes the real-time monitoring and assessment of the coating thermal conductivity, which initially rises under the steady-state high temperature thermal gradient test due to coating sintering, and later drops under the cyclic thermal gradient test due to coating cracking/delamination. The coating system is then evaluated based on damage accumulation and failure after the combined steady-state and cyclic thermal gradient tests. The lattice and radiation thermal conductivity of advanced ceramic coatings can also be evaluated using laser heat-flux techniques. The external radiation resistance of the coating is assessed based on the measured specimen temperature response under a laser- heated intense radiation-flux source. The coating internal radiation contribution is investigated based on the measured apparent coating conductivity increases with the coating surface test temperature under large thermal gradient test conditions. Since an increased radiation contribution is observed at these very high surface test temperatures, by varying the laser heat-flux and coating average test temperature, the complex relation between the lattice and radiation conductivity as a function of surface and interface test temperature may be derived.

SAM Theory Manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Rui

The System Analysis Module (SAM) is an advanced and modern system analysis tool being developed at Argonne National Laboratory under the U.S. DOE Office of Nuclear Energy’s Nuclear Energy Advanced Modeling and Simulation (NEAMS) program. SAM development aims for advances in physical modeling, numerical methods, and software engineering to enhance its user experience and usability for reactor transient analyses. To facilitate the code development, SAM utilizes an object-oriented application framework (MOOSE), and its underlying meshing and finite-element library (libMesh) and linear and non-linear solvers (PETSc), to leverage modern advanced software environments and numerical methods. SAM focuses on modeling advanced reactormore » concepts such as SFRs (sodium fast reactors), LFRs (lead-cooled fast reactors), and FHRs (fluoride-salt-cooled high temperature reactors) or MSRs (molten salt reactors). These advanced concepts are distinguished from light-water reactors in their use of single-phase, low-pressure, high-temperature, and low Prandtl number (sodium and lead) coolants. As a new code development, the initial effort has been focused on modeling and simulation capabilities of heat transfer and single-phase fluid dynamics responses in Sodium-cooled Fast Reactor (SFR) systems. The system-level simulation capabilities of fluid flow and heat transfer in general engineering systems and typical SFRs have been verified and validated. This document provides the theoretical and technical basis of the code to help users understand the underlying physical models (such as governing equations, closure models, and component models), system modeling approaches, numerical discretization and solution methods, and the overall capabilities in SAM. As the code is still under ongoing development, this SAM Theory Manual will be updated periodically to keep it consistent with the state of the development.« less

Analysis and simulation of the I C engine Otto cycle using the second law of thermodynamics

NASA Astrophysics Data System (ADS)

Abdel-Rahim, Y. M.

The present investigation is an application of the second law of thermodynamics to the spark ignition engine cycle. A comprehensive thermodynamic analysis of the air standard cycle is conducted using the first and second laws of thermodynamics, the ideal gas equation of state and the perfect gas properties for air. The study investigates the effect of the cycle parameters on the cycle performance reflected by the first and second law efficiencies, the heat added, the work done, the available energy added as well as the history of the internal, available and unavailable energies along the cycle. The study shows that the second law efficiency is a function of the compression ratio, the initial temperature, the maximum temperature as well as the dead state temperature. A non-dimensional comprehensive thermodynamic simulation model for the actual Otto cycle is developed to study the effects of the design and operating parameters of the cycle on the cycle performance. The analysis takes into account engine geometry, mixture strength, heat transfer, piston motion, engine speed, mechanical friction, spark advance and combustion duration.

Quench Crack Behavior of Nickel-base Disk Superalloys

NASA Technical Reports Server (NTRS)

Gayda, John; Kantzos, Pete; Miller, Jason

2002-01-01

There is a need to increase the temperature capability of superalloy turbine disks to allow higher operating temperatures in advanced aircraft engines. When modifying processing and chemistry of disk alloys to achieve this capability, it is important to preserve the ability to use rapid cooling during supersolvus heat treatments to achieve coarse grain, fine gamma prime microstructures. An important step in this effort is an understanding of the key variables controlling the cracking tendencies of nickel-base disk alloys during quenching from supersolvus heat treatments. The objective of this study was to investigate the quench cracking tendencies of several advanced disk superalloys during simulated heat treatments. Miniature disk specimens were rapidly quenched after solution heat treatments. The responses and failure modes were compared and related to the quench cracking tendencies of actual disk forgings. Cracking along grain boundaries was generally observed to be operative. For the alloys examined in this study, the solution temperature not alloy chemistry was found to be the primary factor controlling quench cracking. Alloys with high solvus temperatures show greater tendency for quench cracking.

Modeling Radiative Heat Transfer and Turbulence-Radiation Interactions in Engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul, Chandan; Sircar, Arpan; Ferreyro-Fernandez, Sebastian

Detailed radiation modelling in piston engines has received relatively little attention to date. Recently, it is being revisited in light of current trends towards higher operating pressures and higher levels of exhaust-gas recirculation, both of which enhance molecular gas radiation. Advanced high-efficiency engines also are expected to function closer to the limits of stable operation, where even small perturbations to the energy balance can have a large influence on system behavior. Here several different spectral radiation property models and radiative transfer equation (RTE) solvers have been implemented in an OpenFOAM-based engine CFD code, and simulations have been performed for amore » full-load (peak pressure ~200 bar) heavy-duty diesel engine. Differences in computed temperature fields, NO and soot levels, and wall heat transfer rates are shown for different combinations of spectral models and RTE solvers. The relative importance of molecular gas radiation versus soot radiation is examined. And the influence of turbulence-radiation interactions is determined by comparing results obtained using local mean values of composition and temperature to compute radiative emission and absorption with those obtained using a particle-based transported probability density function method.« less

Tubular copper thrust chamber design study

NASA Technical Reports Server (NTRS)

Masters, A. I.; Galler, D. E.

1992-01-01

The use of copper tubular thrust chambers is particularly important in high performance expander cycle space engines. Tubular chambers have more surface area than flat wall chambers, and this extra surface area provides enhanced heat transfer for additional energy to power the cycle. This paper was divided into two sections: (1) a thermal analysis and sensitivity study; and (2) a preliminary design of a selected thrust chamber configuration. The thermal analysis consisted of a statistical optimization to determine the optimum tube geometry, tube booking, thrust chamber geometry, and cooling routing to achieve the maximum upper limit chamber pressure for a 25,000 pound thrust engine. The preliminary design effort produced a layout drawing of a tubular thrust chamber that is three inches shorter than the Advanced Expander Test Bed (AETB) milled channel chamber but is predicted to provide a five percent increase in heat transfer. Testing this chamber in the AETB would confirm the inherent advantages of tubular chamber construction and heat transfer.

Thermodynamic Analysis of Dual-Mode Scramjet Engine Operation and Performance

NASA Technical Reports Server (NTRS)

Riggins, David; Tacket, Regan; Taylor, Trent; Auslender, Aaron

2006-01-01

Recent analytical advances in understanding the performance continuum (the thermodynamic spectrum) for air-breathing engines based on fundamental second-law considerations have clarified scramjet and ramjet operation, performance, and characteristics. Second-law based analysis is extended specifically in this work to clarify and describe the performance characteristics for dual-mode scramjet operation in the mid-speed range of flight Mach 4 to 7. This is done by a fundamental investigation of the complex but predictable interplay between heat release and irreversibilities in such an engine; results demonstrate the flow and performance character of the dual mode regime and of dual mode transition behavior. Both analytical and computational (multi-dimensional CFD) studies of sample dual-mode flow-fields are performed in order to demonstrate the second-law capability and performance and operability issues. The impact of the dual-mode regime is found to be characterized by decreasing overall irreversibility with increasing heat release, within the operability limits of the system.

Natural gas applications for hybrid vehicles. Final report, October 1992-July 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bentley, J.M.

1993-08-01

Hybrid vehicle technology holds the potential for improved efficiency and emissions compared with internal combustion (IC) engines and improved range and refueling convenience over electric vehicles. This study evaluated the potential for using natural gas as a hybrid vehicle fuel. Potential regulatory and market drivers were evaluated for hybrids generally and natural gas hybrids in specific. Heat engine options and other configuration issues were investigated to determine efficiency, emissions or other benefits of light- and heavy-duty hybrids. Several hybrid vehicle configurations were evaluated to determine the specific packaging attributes of natural gas in a hybrid configuration. Generally, conventional IC enginesmore » appear adequate for most emissions-sensitive hybrid applications with no great advantage being gained from using turbines or other more advanced heat engines. The largest technology barrier to a near-term hybrid is the weight of available or near-term batteries. Smaller, light-duty hybrid vehicles will be more sensitive to this weight handicap than larger vehicles such as the urban transit bus.« less

Military markets for solar thermal electric power systems

NASA Technical Reports Server (NTRS)

Hauger, J. S.

1980-01-01

The Department of Defense maintains an inventory of over 1,800 MW of engine-generators 15 KW and larger, with an estimated procurement rate of over 140 MW/year. Nearly the entire requirement could be met by advanced heat engines of the types being developed as point-focussing, distributed receiver power plants. A conceptual system consisting of a heat engine which efficiently burns liquid fossil or synthetic fuels, with a 'solarization kit' for conversion to hybrid solar operation could meet existing DOD requirements for new systems which are quieter, lighter, and multi-fueled. An estimated 24 percent (33 MW/year) or more could operationally benefit from the solar option. Baseline cost projections indicate levelized energy cost goals of 210 to 120 mills/KWh (15 to 1000 KW systems). Fuel cost escalation is the major factor affecting the value of the solar option. A baseline calculation for fuel at $0.59/gal in spring, 1979, escalating at 8 percent above general inflation indicates a value of $2700/KWe for a solarization kit.

Development of high temperature liquid lubricants for low-heat rejection: Heavy duty diesel engines

NASA Technical Reports Server (NTRS)

Wiczynski, P. D.; Marolewski, T. A.

1993-01-01

The objective of this DOE program was to develop a liquid lubricant that will allow advanced diesel engines to operate at top ring reversal temperatures approaching 500 C and sump temperatures approaching 250 C. The lubricants developed demonstrated at marginal increase in sump temperature capability, approximately 15 C, and an increase in top ring reversal temperature. A 15W-40 synthetic lubricant designated HTL-4 was the best lubricant developed in terms of stability, wear control, deposit control dispersancy, and particulate emissions.

The Effect of Tungsten and Niobium on the Stress Relaxation Rates of Disk Alloy CH98

NASA Technical Reports Server (NTRS)

Gayda, John

2003-01-01

Gas turbine engines for future subsonic transports will probably have higher pressure ratios which will require nickel-base superalloy disks with 1300 to 1400 F temperature capability. Several advanced disk alloys are being developed to fill this need. One of these, CH98, is a promising candidate for gas turbine engines and is being studied in NASA s Advanced Subsonic Technology (AST) program. For large disks, residual stresses generated during quenching from solution heat treatment are often reduced by a stabilization heat treatment, in which the disk is heated to 1500 to 1600 F for several hours followed by a static air cool. The reduction in residual stress levels lessens distortion during machining of disks. However, previous work on CH98 has indicated that stabilization treatments decrease creep capability. Additions of the refractory elements tungsten and niobium improve tensile and creep properties after stabilization, while maintaining good crack growth resistance at elevated temperatures. As the additions of refractory elements increase creep capability, they might also effect stress relaxation rates and therefore the reduction in residual stress levels obtained for a given stabilization treatment. To answer this question, the stress relaxation rates of CH98 with and without tungsten and niobium additions are compared in this paper for temperatures and times generally employed in stabilization treatments on modern disk alloys.

Study of the collector/heat pipe cooled externally configured thermionic diode

NASA Technical Reports Server (NTRS)

1973-01-01

A collector/heat pipe cooled, externally configured (heated) thermionic diode module was designed for use in a laboratory test to demonstrate the applicability of this concept as the fuel element/converter module of an in-core thermionic electric power source. During the course of the program, this module evolved from a simple experimental mock-up into an advanced unit which was more reactor prototypical. Detailed analysis of all diode components led to their engineering design, fabrication, and assembly, with the exception of the collector/heat pipe. While several designs of high power annular wicked heat pipes were fabricated and tested, each exhibited unexpected performance difficulties. It was concluded that the basic cause of these problems was the formation of crud which interfered with the liquid flow in the annular passage of the evaporator region.

An Introduction to Magnetohydrodynamics

NASA Astrophysics Data System (ADS)

Davidson, P. A.

2001-03-01

Magnetic fields are routinely used in industry to heat, pump, stir and levitate liquid metals. There is the terrestrial magnetic field that is maintained by fluid motion in the earth's core, the solar magnetic field, which generates sunspots and solar flares, and the galactic field that influences the formation of stars. This introductory text on magnetohydrodynamics (MHD) (the study of the interaction of magnetic fields and conducting fluids) is intended to serve as an introductory text for advanced undergraduates and graduate students in physics, applied mathematics and engineering. The material in the text is heavily weighted toward incompressible flows and to terrestrial (as distinct from astrophysical) applications. The final sections of the text, which outline the latest advances in the metallurgical applications of MHD, make the book of interest to professional researchers in applied mathematics, engineering and metallurgy.

The prediction of nozzle performance and heat transfer in hydrogen/oxygen rocket engines with transpiration cooling, film cooling, and high area ratios

NASA Technical Reports Server (NTRS)

Kacynski, Kenneth J.; Hoffman, Joe D.

1993-01-01

An advanced engineering computational model has been developed to aid in the analysis and design of hydrogen/oxygen chemical rocket engines. The complete multi-species, chemically reacting and diffusing Navier-Stokes equations are modelled, finite difference approach that is tailored to be conservative in an axisymmetric coordinate system for both the inviscid and viscous terms. Demonstration cases are presented for a 1030:1 area ratio nozzle, a 25 lbf film cooled nozzle, and transpiration cooled plug-and-spool rocket engine. The results indicate that the thrust coefficient predictions of the 1030:1 nozzle and the film cooled nozzle are within 0.2 to 0.5 percent, respectively, of experimental measurements when all of the chemical reaction and diffusion terms are considered. Further, the model's predictions agree very well with the heat transfer measurements made in all of the nozzle test cases. The Soret thermal diffusion term is demonstrated to have a significant effect on the predicted mass fraction of hydrogen along the wall of the nozzle in both the laminar flow 1030:1 nozzle and the turbulent plug-and-spool rocket engine analysis cases performed. Further, the Soret term was shown to represent a significant fraction of the diffusion fluxes occurring in the transpiration cooled rocket engine.

Experimental Investigation of Turbine Vane Heat Transfer for Alternative Fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nix, Andrew Carl

The focus of this program was to experimentally investigate advanced gas turbine cooling schemes and the effects of and factors that contribute to surface deposition from particulate matter found in coal syngas exhaust flows on turbine airfoil heat transfer and film cooling, as well as to characterize surface roughness and determine the effects of surface deposition on turbine components. The program was a comprehensive, multi-disciplinary collaborative effort between aero-thermal and materials faculty researchers and the Department of Energy, National Energy Technology Laboratory (NETL). The primary technical objectives of the program were to evaluate the effects of combustion of syngas fuelsmore » on heat transfer to turbine vanes and blades in land-based power generation gas turbine engines. The primary questions to be answered by this investigation were; What are the factors that contribute to particulate deposition on film cooled gas turbine components? An experimental program was performed in a high-temperature and pressure combustion rig at the DOE NETL; What is the effect of coal syngas combustion and surface deposition on turbine airfoil film cooling? Deposition of particulate matter from the combustion gases can block film cooling holes, decreasing the flow of the film coolant and the film cooling effectiveness; How does surface deposition from coal syngas combustion affect turbine surface roughness? Increased surface roughness can increase aerodynamic losses and result in decreased turbine hot section efficiency, increasing engine fuel consumption to maintain desired power output. Convective heat transfer is also greatly affected by the surface roughness of the airfoil surface; Is there any significant effect of surface deposition or erosion on integrity of turbine airfoil thermal barrier coatings (TBC) and do surface deposits react with the TBC in any way to decrease its thermal insulating capability? Spallation and erosion of TBC is a persistent problem in modern turbine engines; and What advancements in film cooling hole geometry and design can increase effectiveness of film cooling in turbines burning high-hydrogen coal syngas due to the higher heat loads and mass flow rates of the core flow? Experimental and numerical investigations of advanced cooling geometries that can improve resistance to surface deposition were performed. The answers to these questions were investigated through experimental measurements of turbine blade surface temperature and coolant coverage (via infrared camera images and thermocouples) and time-varying surface roughness in the NETL high-pressure combustion rig with accelerated, simulated surface deposition and advanced cooling hole concepts, coupled with detailed materials analysis and characterization using conventional methods of Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), 3-D Surface Topography (using a 3-D stylus profilometer). Detailed surface temperatures and cooling effectiveness could not be measured due to issues with the NETL infrared camera system. In collaboration with faculty startup funding from the principal investigator, experimental and numerical investigations were performed of an advanced film cooling hole geometry, the anti-vortex hole (AVH), focusing on improving cooling effectiveness and decreasing the counter-rotating vortex of conventional cooling holes which can entrain mainstream particulate matter to the surface. The potential benefit of this program is in gaining a fundamental understanding of how the use of alternative fuels will effect the operation of modern gas turbine engines, providing valuable data for more effective cooling designs for future turbine systems utilizing alternative fuels.« less

Advanced vehicle systems assessment. Volume 3: Systems assessment

NASA Technical Reports Server (NTRS)

Hardy, K.

1985-01-01

The systems analyses integrate the advanced component and vehicle characteristics into conceptual vehicles with identical performance (for a given application) and evaluates the vehicles in typical use patterns. Initial and life-cycle costs are estimated and compared to conventional reference vehicles with comparable technological advances, assuming the vehicles will be in competition in the early 1990s. Electric vans, commuter vehicles, and full-size vehicles, in addition to electric/heat-engine hybrid and fuel-cell powered vehicles, are addressed in terms of performance and economics. System and subsystem recommendations for vans and two-passenger commuter vehicles are based on the economic analyses in this volume.

Orbit transfer rocket engine technology program

NASA Technical Reports Server (NTRS)

Gustafson, N. B.; Harmon, T. J.

1993-01-01

An advanced near term (1990's) space-based Orbit Transfer Vehicle Engine (OTVE) system was designed, and the technologies applicable to its construction, maintenance, and operations were developed under Tasks A through F of the Orbit Transfer Rocket Engine Technology Program. Task A was a reporting task. In Task B, promising OTV turbomachinery technologies were explored: two stage partial admission turbines, high velocity ratio diffusing crossovers, soft wear ring seals, advanced bearing concepts, and a rotordynamic analysis. In Task C, a ribbed combustor design was developed. Possible rib and channel geometries were chosen analytically. Rib candidates were hot air tested and laser velocimeter boundary layer analyses were conducted. A channel geometry was also chosen on the basis of laser velocimeter data. To verify the predicted heat enhancement effects, a ribbed calorimeter spool was hot fire tested. Under Task D, the optimum expander cycle engine thrust, performance and envelope were established for a set of OTV missions. Optimal nozzle contours and quick disconnects for modularity were developed. Failure Modes and Effects Analyses, maintenance and reliability studies and component study results were incorporated into the engine system. Parametric trades on engine thrust, mixture ratio, and area ratio were also generated. A control system and the health monitoring and maintenance operations necessary for a space-based engine were outlined in Task E. In addition, combustor wall thickness measuring devices and a fiberoptic shaft monitor were developed. These monitoring devices were incorporated into preflight engine readiness checkout procedures. In Task F, the Integrated Component Evaluator (I.C.E.) was used to demonstrate performance and operational characteristics of an advanced expander cycle engine system and its component technologies. Sub-system checkouts and a system blowdown were performed. Short transitions were then made into main combustor ignition and main stage operation.

Application of scanning acoustic microscopy to advanced structural ceramics

NASA Technical Reports Server (NTRS)

Vary, Alex; Klima, Stanley J.

1987-01-01

A review is presentod of research investigations of several acoustic microscopy techniques for application to structural ceramics for advanced heat engines. Results obtained with scanning acoustic microscopy (SAM), scanning laser acoustic microscopy (SLAM), scanning electron acoustic microscopy (SEAM), and photoacoustic microscopy (PAM) are compared. The techniques were evaluated on research samples of green and sintered monolithic silicon nitrides and silicon carbides in the form of modulus-of-rupture bars containing deliberately introduced flaws. Strengths and limitations of the techniques are described with emphasis on statistics of detectability of flaws that constitute potential fracture origins.

Continuous fiber ceramic matrix composites for heat engine components

NASA Technical Reports Server (NTRS)

Tripp, David E.

1988-01-01

High strength at elevated temperatures, low density, resistance to wear, and abundance of nonstrategic raw materials make structural ceramics attractive for advanced heat engine applications. Unfortunately, ceramics have a low fracture toughness and fail catastrophically because of overload, impact, and contact stresses. Ceramic matrix composites provide the means to achieve improved fracture toughness while retaining desirable characteristics, such as high strength and low density. Materials scientists and engineers are trying to develop the ideal fibers and matrices to achieve the optimum ceramic matrix composite properties. A need exists for the development of failure models for the design of ceramic matrix composite heat engine components. Phenomenological failure models are currently the most frequently used in industry, but they are deterministic and do not adequately describe ceramic matrix composite behavior. Semi-empirical models were proposed, which relate the failure of notched composite laminates to the stress a characteristic distance away from the notch. Shear lag models describe composite failure modes at the micromechanics level. The enhanced matrix cracking stress occurs at the same applied stress level predicted by the two models of steady state cracking. Finally, statistical models take into consideration the distribution in composite failure strength. The intent is to develop these models into computer algorithms for the failure analysis of ceramic matrix composites under monotonically increasing loads. The algorithms will be included in a postprocessor to general purpose finite element programs.

Development and testing of dry chemicals in advanced extinguishing systems for jet engine nacelle fires

NASA Technical Reports Server (NTRS)

Altman, R. L.; Ling, A. C. (Editor); Mayer, L. A.; Myronik, D. J.

1979-01-01

The effectiveness of dry chemical in extinguishing and delaying reignition of fires resulting from hydrocarbon fuel leaking onto heated surfaces such as can occur in jet engine nacelles is studied. The commercial fire extinguishant dry chemical tried are sodium and potassium bicarbonate, carbonate, chloride, carbamate (Monnex), metal halogen, and metal hydroxycarbonate compounds. Synthetic and preparative procedures for new materials developed, a new concept of fire control by dry chemical agents, descriptions of experiment assemblages to test dry chemical fire extinguishant efficiencies in controlling fuel fires initiated by hot surfaces, comparative testing data for more than 25 chemical systems in a 'static' assemblage with no air flow across the heated surface, and similar comparative data for more than ten compounds in a dynamic system with air flows up to 350 ft/sec are presented.

Assessment of alternative power sources for mobile mining machinery

NASA Technical Reports Server (NTRS)

Cairelli, J. E.; Tomazic, W. A.; Evans, D. G.; Klann, J. L.

1981-01-01

Alternative mobile power sources for mining applications were assessed. A wide variety of heat engines and energy systems was examined as potential alternatives to presently used power systems. The present mobile power systems are electrical trailing cable, electrical battery, and diesel - with diesel being largely limited in the United States to noncoal mines. Each candidate power source was evaluated for the following requirements: (1) ability to achieve the duty cycle; (2) ability to meet Government regulations; (3) availability (production readiness); (4) market availability; and (5) packaging capability. Screening reduced the list of candidates to the following power sources: diesel, stirling, gas turbine, rankine (steam), advanced electric (batteries), mechanical energy storage (flywheel), and use of hydrogen evolved from metal hydrides. This list of candidates is divided into two classes of alternative power sources for mining applications, heat engines and energy storage systems.

Quantum Feynman Ratchet

NASA Astrophysics Data System (ADS)

Goyal, Ketan; Kawai, Ryoichi

As nanotechnology advances, understanding of the thermodynamic properties of small systems becomes increasingly important. Such systems are found throughout physics, biology, and chemistry manifesting striking properties that are a direct result of their small dimensions where fluctuations become predominant. The standard theory of thermodynamics for macroscopic systems is powerless for such ever fluctuating systems. Furthermore, as small systems are inherently quantum mechanical, influence of quantum effects such as discreteness and quantum entanglement on their thermodynamic properties is of great interest. In particular, the quantum fluctuations due to quantum uncertainty principles may play a significant role. In this talk, we investigate thermodynamic properties of an autonomous quantum heat engine, resembling a quantum version of the Feynman Ratchet, in non-equilibrium condition based on the theory of open quantum systems. The heat engine consists of multiple subsystems individually contacted to different thermal environments.

Advances in cryogenic engineering. Vols. 35A & 35B - Proceedings of the 1989 Cryogenic Engineering Conference, University of California, Los Angeles, July 24-28, 1989

NASA Astrophysics Data System (ADS)

Fast, R. W.

The book presents a review of literature on superfluid helium, together with papers under the topics on heat and mass transfer in He II; applications of He II for cooling superconducting devices in space; heat transfer to liquid helium and liquid nitrogen; multilayer insulation; applications of superconductivity, including topics on magnets and other devices, magnet stability and coil protection, and cryogenic techniques; and refrigeration for electronics. Other topics discussed include refrigeration of superconducting systems; the expanders, cold compressors, and pumps for liquid helium; dilution refrigerators; magnetic refrigerators; pulse tube refrigerators; cryocoolers for space applications; properties of cryogenic fluids; cryogenic instrumentation; hyperconducting devices (cryogenic magnets); cryogenic applications in space science and technology and in transportation; and miscellaneous cryogenic techniques and applications.

Assessment of alternative power sources for mobile mining machinery

NASA Astrophysics Data System (ADS)

Cairelli, J. E.; Tomazic, W. A.; Evans, D. G.; Klann, J. L.

1981-12-01

Alternative mobile power sources for mining applications were assessed. A wide variety of heat engines and energy systems was examined as potential alternatives to presently used power systems. The present mobile power systems are electrical trailing cable, electrical battery, and diesel - with diesel being largely limited in the United States to noncoal mines. Each candidate power source was evaluated for the following requirements: (1) ability to achieve the duty cycle; (2) ability to meet Government regulations; (3) availability (production readiness); (4) market availability; and (5) packaging capability. Screening reduced the list of candidates to the following power sources: diesel, stirling, gas turbine, rankine (steam), advanced electric (batteries), mechanical energy storage (flywheel), and use of hydrogen evolved from metal hydrides. This list of candidates is divided into two classes of alternative power sources for mining applications, heat engines and energy storage systems.

Preliminary assessment of rover power systems for the Mars Rover Sample Return Mission

NASA Technical Reports Server (NTRS)

Bents, D. J.

1989-01-01

Four isotope power system concepts were presented and compared on a common basis for application to on-board electrical prime power for an autonomous planetary rover vehicle. A representative design point corresponding to the Mars Rover Sample Return (MRSR) preliminary mission requirements (500 W) was selected for comparison purposes. All systems concepts utilize the General Purpose Heat Source (GPHS) isotope heat source developed by DOE. Two of the concepts employ thermoelectric (TE) conversion: one using the GPHS Radioisotope Thermoelectric Generator (RTG) used as a reference case, the other using an advanced RTG with improved thermoelectric materials. The other two concepts employed are dynamic isotope power systems (DIPS): one using a closed Brayton cycle (CBC) turboalternator, and the other using a free piston Stirling cycle engine/linear alternator (FPSE) with integrated heat source/heater head. Near-term technology levels have been assumed for concept characterization using component technology figure-of-merit values taken from the published literature. For example, the CBC characterization draws from the historical test database accumulated from space Brayton cycle subsystems and components from the NASA B engine through the mini-Brayton rotating unit. TE system performance is estimated from Voyager/multihundred Watt (MHW)-RTG flight experience through Mod-RTG performance estimates considering recent advances in TE materials under the DOD/DOE/NASA SP-100 and NASA Committee on Scientific and Technological Information programs. The Stirling DIPS system is characterized from scaled-down Space Power Demonstrator Engine (SPDE) data using the GPHS directly incorporated into the heater head. The characterization/comparison results presented here differ from previous comparison of isotope power (made for LEO applications) because of the elevated background temperature on the Martian surface compared to LEO, and the higher sensitivity of dynamic systems to elevated s

Review and assessment of the database and numerical modeling for turbine heat transfer

NASA Technical Reports Server (NTRS)

Gladden, H. J.; Simoneau, R. J.

1988-01-01

The objectives of the HOST Turbine Heat Transfer subproject were to obtain a better understanding of the physics of the aerothermodynamic phenomena and to assess and improve the analytical methods used to predict the flow and heat transfer in high-temperature gas turbines. At the time the HOST project was initiated, an across-the-board improvement in turbine design technology was needed. A building-block approach was utilized and the research ranged from the study of fundamental phenomena and modeling to experiments in simulated real engine environments. Experimental research accounted for approximately 75 percent of the funding while the analytical efforts were approximately 25 percent. A healthy government/industry/university partnership, with industry providing almost half of the research, was created to advance the turbine heat transfer design technology base.

Improved silicon nitride for advanced heat engines

NASA Technical Reports Server (NTRS)

Yeh, Hun C.; Fang, Ho T.

1987-01-01

The technology base required to fabricate silicon nitride components with the strength, reliability, and reproducibility necessary for actual heat engine applications is presented. Task 2 was set up to develop test bars with high Weibull slope and greater high temperature strength, and to conduct an initial net shape component fabrication evaluation. Screening experiments were performed in Task 7 on advanced materials and processing for input to Task 2. The technical efforts performed in the second year of a 5-yr program are covered. The first iteration of Task 2 was completed as planned. Two half-replicated, fractional factorial (2 sup 5), statistically designed matrix experiments were conducted. These experiments have identified Denka 9FW Si3N4 as an alternate raw material to GTE SN502 Si3N4 for subsequent process evaluation. A detailed statistical analysis was conducted to correlate processing conditions with as-processed test bar properties. One processing condition produced a material with a 97 ksi average room temperature MOR (100 percent of goal) with 13.2 Weibull slope (83 percent of goal); another condition produced 86 ksi (6 percent over baseline) room temperature strength with a Weibull slope of 20 (125 percent of goal).

Dual Expander Cycle Rocket Engine with an Intermediate, Closed-cycle Heat Exchanger

NASA Technical Reports Server (NTRS)

Greene, William D. (Inventor)

2008-01-01

A dual expander cycle (DEC) rocket engine with an intermediate closed-cycle heat exchanger is provided. A conventional DEC rocket engine has a closed-cycle heat exchanger thermally coupled thereto. The heat exchanger utilizes heat extracted from the engine's fuel circuit to drive the engine's oxidizer turbomachinery.

Advanced tendencies in development of photovoltaic cells for power engineering

NASA Astrophysics Data System (ADS)

Strebkov, D. S.

2015-01-01

Development of solar power engineering must be based on original innovative Russian and world technologies. It is necessary to develop promising Russian technologies of manufacturing of photovoltaic cells and semiconductor materials: chlorine-free technology for obtaining solar silicon; matrix solar cell technology with an efficiency of 25-30% upon the conversion of concentrated solar, thermal, and laser radiation; encapsulation technology for high-voltage silicon solar modules with a voltage up to 1000 V and a service life up to 50 years; new methods of concentration of solar radiation with the balancing illumination of photovoltaic cells at 50-100-fold concentration; and solar power systems with round-the-clock production of electrical energy that do not require energy storage devices and reserve sources of energy. The advanced tendency in silicon power engineering is the use of high-temperature reactions in heterogeneous modular silicate solutions for long-term (over one year) production of heat and electricity in the autonomous mode.

Test results of a Stirling engine utilizing heat exchanger modules with an integral heat pipe

NASA Astrophysics Data System (ADS)

Skupinski, Robert C.; Tower, Leonard K.; Madi, Frank J.; Brusk, Kevin D.

1993-04-01

The Heat Pipe Stirling Engine (HP-1000), a free-piston Stirling engine incorporating three heat exchanger modules, each having a sodium filled heat pipe, has been tested at the NASA-Lewis Research Center as part of the Civil Space Technology Initiative (CSTI). The heat exchanger modules were designed to reduce the number of potential flow leak paths in the heat exchanger assembly and incorporate a heat pipe as the link between the heat source and the engine. An existing RE-1000 free-piston Stirling engine was modified to operate using the heat exchanger modules. This paper describes heat exchanger module and engine performance during baseline testing. Condenser temperature profiles, brake power, and efficiency are presented and discussed.

Test results of a Stirling engine utilizing heat exchanger modules with an integral heat pipe

NASA Technical Reports Server (NTRS)

Skupinski, Robert C.; Tower, Leonard K.; Madi, Frank J.; Brusk, Kevin D.

1993-01-01

The Heat Pipe Stirling Engine (HP-1000), a free-piston Stirling engine incorporating three heat exchanger modules, each having a sodium filled heat pipe, has been tested at the NASA-Lewis Research Center as part of the Civil Space Technology Initiative (CSTI). The heat exchanger modules were designed to reduce the number of potential flow leak paths in the heat exchanger assembly and incorporate a heat pipe as the link between the heat source and the engine. An existing RE-1000 free-piston Stirling engine was modified to operate using the heat exchanger modules. This paper describes heat exchanger module and engine performance during baseline testing. Condenser temperature profiles, brake power, and efficiency are presented and discussed.

High Temperature Propulsion System Structural Seals for Future Space Launch Vehicles

NASA Technical Reports Server (NTRS)

Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; DeMange, Jeffrey J.

2004-01-01

Durable, flexible sliding seals are required in advanced hypersonic engines to seal the perimeters of movable engine ramps for efficient, safe operation in high heat flux environments at temperatures of 2000 to 2500 F. Current seal designs do not meet the demanding requirements for future engines, so NASA s Glenn Research Center is developing advanced seals and preloading devices to overcome these shortfalls. An advanced ceramic wafer seal design and two types of seal preloading devices were evaluated in a series of compression, scrub, and flow tests. Silicon nitride wafer seals survived 2000 in. 1000 cycles) of scrubbing at 1600 F against an Inconel 625 rub surface with no chips or signs of damage. Flow rates measured for the wafers before and after scrubbing were almost identical and were up to 32 times lower than those recorded for the best braided rope seal flow blockers. Canted coil springs and silicon nitride compression springs showed promise conceptually as potential seal preloading devices to help maintain seal resiliency. A finite element model of the canted coil spring revealed that it should be possible to produce a spring out of high temperature materials for applications at 2000+ F.

High Temperature Propulsion System Structural Seals for Future Space Launch Vehicles

NASA Technical Reports Server (NTRS)

Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; DeMange, Jeffrey J.

2003-01-01

Durable, flexible sliding seals are required in advanced hypersonic engines to seal the perimeters of movable engine ramps for efficient, safe operation in high heat flux environments at temperatures of 2000 to 2500 F. Current seal designs do not meet the demanding requirements for future engines, so NASA's Glenn Research Center is developing advanced seals and preloading devices to overcome these shortfalls. An advanced ceramic wafer seal design and two types of seal preloading devices were evaluated in a series of compression, scrub, and flow tests. Silicon nitride wafer seals survived 2000 in. (1000 cycles) of scrubbing at room temperature against an Inconel 625 rub surface with no chips or signs of damage. Flow rates measured for the wafers before and after scrubbing were almost identical and were much lower than those recorded for the best braided rope seal flow blockers. Canted coil springs and silicon nitride compression springs showed promise conceptually as potential seal preloading devices to help maintain seal resiliency. A finite element model of the canted coil spring revealed that it should be possible to produce a spring out of high temperature materials for applications at 2000+ F.

Advanced Stirling Duplex Materials Assessment for Potential Venus Mission Heater Head Application

NASA Technical Reports Server (NTRS)

Ritzert, Frank; Nathal, Michael V.; Salem, Jonathan; Jacobson, Nathan; Nesbitt, James

2011-01-01

This report will address materials selection for components in a proposed Venus lander system. The lander would use active refrigeration to allow Space Science instrumentation to survive the extreme environment that exists on the surface of Venus. The refrigeration system would be powered by a Stirling engine-based system and is termed the Advanced Stirling Duplex (ASD) concept. Stirling engine power conversion in its simplest definition converts heat from radioactive decay into electricity. Detailed design decisions will require iterations between component geometries, materials selection, system output, and tolerable risk. This study reviews potential component requirements against known materials performance. A lower risk, evolutionary advance in heater head materials could be offered by nickel-base superalloy single crystals, with expected capability of approximately 1100C. However, the high temperature requirements of the Venus mission may force the selection of ceramics or refractory metals, which are more developmental in nature and may not have a well-developed database or a mature supporting technology base such as fabrication and joining methods.

Improved silicon carbide for advanced heat engines. II - Pressureless sintering and mechanical properties of injection molded silicon carbide

NASA Technical Reports Server (NTRS)

Whalen, Thomas J.; Baer, J. R.

1989-01-01

The influence on density and strength of pressureless sintering in vacuum and argon environments has been evaluated with injection molded SiC materials. Main effects and two factor interactions of sintering (cycle variables temperature, time, heating rate, and atmosphere) were assessed. An improved understanding of the influence of the processing flaws and sintering conditions has been obtained. Strength and density have improved from a baseline level of 299 MPa (43.3 Ksi) and 94 pct of theoretical density to values greater than 483 MPa (70 Ksi) and 97 pct.

Microtube strip heat exchanger

NASA Astrophysics Data System (ADS)

Doty, F. D.

1991-10-01

This progress report is for the September-October 1991 quarter. We have demonstrated feasibility of higher specific conductance by a factor of five than any other work in high-temperature gas-to-gas exchangers. These laminar-flow, microtube exchangers exhibit extremely low pressure drop compared to alternative compact designs under similar conditions because of their much shorter flow length and larger total flow area for lower flow velocities. The design appears to be amenable to mass production techniques, but considerable process development remains. The reduction in materials usage and the improved heat exchanger performance promise to be of enormous significance in advanced engine designs and in cryogenics.

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.

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

On behalf of the Department of Energy's Office of FreedomCAR and Vehicle Technologies, we are pleased to introduce the Fiscal Year (FY) 2004 Annual Progress Report for the Advanced Combustion Engine R&D Sub-Program. The mission of the FreedomCAR and Vehicle Technologies Program is to develop more energy efficient and environmentally friendly highway transportation technologies that enable Americans to use less petroleum for their vehicles. The Advanced Combustion Engine R&D Sub-Program supports this mission by removing the critical technical barriers to commercialization of advanced internal combustion engines for light-, medium-, and heavy-duty highway vehicles that meet future Federal and state emissionsmore » regulations. The primary objective of the Advanced Combustion Engine R&D Sub-Program is to improve the brake thermal efficiency of internal combustion engines from 30 to 45 percent for light-duty applications by 2010; and 40 to 55 percent for heavy-duty applications by 2012; while meeting cost, durability, and emissions constraints. R&D activities include work on combustion technologies that increase efficiency and minimize in-cylinder formation of emissions, as well as aftertreatment technologies that further reduce exhaust emissions. Work is also being conducted on ways to reduce parasitic and heat transfer losses through the development and application of thermoelectrics and turbochargers that include electricity generating capability, and conversion of mechanically driven engine components to be driven via electric motors. This introduction serves to outline the nature, current progress, and future directions of the Advanced Combustion Engine R&D Sub-Program. The research activities of this Sub-Program are planned in conjunction with the FreedomCAR Partnership and the 21st Century Truck Partnership and are carried out in collaboration with industry, national laboratories, and universities. Because of the importance of clean fuels in achieving low emissions, R&D activities are closely coordinated with the relevant activities of the Fuel Technologies Sub-Program, also within the Office of FreedomCAR and Vehicle Technologies. Research is also being undertaken on hydrogen-fueled internal combustion engines to provide an interim hydrogen-based powertrain technology that promotes the longer-range FreedomCAR Partnership goal of transitioning to a hydrogen-fueled transportation system. Hydrogen engine technologies being developed have the potential to provide diesel-like engine efficiencies with near-zero emissions.« less

Technical Support Document: The Development of the Advanced Energy Design Guide for Highway Lodging Buildings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Wei; Jarnagin, Ronald E.; Gowri, Krishnan

2008-09-30

This Technical Support Document (TSD) describes the process and methodology for development of the Advanced Energy Design Guide for Highway Lodgings (AEDG-HL or the Guide), a design guidance document intended to provide recommendations for achieving 30% energy savings in highway lodging properties over levels contained in ANSI/ASHRAE/IESNA Standard 90.1-1999, Energy Standard for Buildings Except Low-Rise Residential Buildings. The AEDG-HL is the fifth in a series of guides being developed by a partnership of organizations, including the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IESNA),more » the United States Green Buildings Council (USGBC), and the U.S. Department of Energy (DOE).« less

Development of thermoacoustic engine operating by waste heat from cooking stove

NASA Astrophysics Data System (ADS)

Chen, B. M.; Abakr, Y. A.; Riley, P. H.; Hann, D. B.

2012-06-01

There are about 1.5 billion people worldwide use biomass as their primary form of energy in household cooking[1]. They do not have access to electricity, and are too remote to benefit from grid electrical supply. In many rural communities, stoves are made without technical advancements, mostly using open fires cooking stoves which have been proven to be extremely low efficiency, and about 93% of the energy generated is lost during cooking. The cooking is done inside a dwelling and creates significant health hazard to the family members and pollution to environment. SCORE (www.score.uk.com) is an international collaboration research project to design and build a low-cost, high efficiency woodstove that uses about half amount of the wood of an open wood fire, and uses the waste heat of the stove to power a thermoacoustic engine (TAE) to produce electricity for applications such as LED lighting, charging mobile phones or charging a 12V battery. This paper reviews on the development of two types of the thermoacoustic engine powered by waste heat from cooking stove which is either using Propane gas or burning of wood as a cooking energy to produce an acceptable amount of electricity for the use of rural communities.

Impact of future fuel properties on aircraft engines and fuel systems

NASA Technical Reports Server (NTRS)

Rudey, R. A.; Grobman, J. S.

1978-01-01

The effect of modifications in hydrocarbon jet fuels specifications on engine performance, component durability and maintenance, and aircraft fuel system performance is discussed. Specific topics covered include: specific fuel consumption; ignition at relight limits; exhaust emissions; combustor liner temperatures; carbon deposition; gum formation in fuel nozzles, erosion and corrosion of turbine blades and vanes; deposits in fuel system heat exchangers; and pumpability and flowability of the fuel. Data that evaluate the ability of current technology aircraft to accept fuel specification changes are presented, and selected technological advances that can reduce the severity of the problems are described and discussed.

Required technologies for a lunar optical UV-IR synthesis array

NASA Technical Reports Server (NTRS)

Johnson, Stewart W.; Wetzel, John P.

1992-01-01

A Lunar Optical UV-IR Synthesis Array (LOUISA) proposed to take advantage of the characteristics of the lunar environment requires appropriate advances in technology. These technologies are in the areas of contamination/interference control, test and evaluation, manufacturing, construction, autonomous operations and maintenance, power and heating/cooling, stable precision structures, optics, parabolic antennas, and communications/control. LOUISA needs to be engineered to operate for long periods with minimal intervention by humans or robots. What is essential for LOUISA operation is enforcement of a systems engineering approach that makes compatible all lunar operations associated with habitation, resource development, and science.

Advanced space engine powerhead breadboard assembly system study

NASA Technical Reports Server (NTRS)

Campbell, R. G.

1978-01-01

The objective of this study was to establish a preliminary design of a Powerhead Breadboard Assembly (PBA) for an 88 964-Newton (20,000-pound) thrust oxygen/hydrogen staged combustion cycle engine for use in orbital transfer vehicle propulsion. Existing turbopump, preburner, and thrust chamber components were integrated with interconnecting ducting, a heat exchanger, and a control system to complete the PBA design. Cycle studies were conducted to define starting transients and steady-state balances for the completed design. Specifications were developed for all valve applications and the conditions required for the control system integration with the facility for system test were defined.

Improved silicon nitride for advanced heat engines

NASA Technical Reports Server (NTRS)

Yeh, H. C.; Wimmer, J. M.

1986-01-01

Silicon nitride is a high temperature material currently under consideration for heat engine and other applications. The objective is to improve the net shape fabrication technology of Si3N4 by injection molding. This is to be accomplished by optimizing the process through a series of statistically designed matrix experiments. To provide input to the matrix experiments, a wide range of alternate materials and processing parameters was investigated throughout the whole program. The improvement in the processing is to be demonstrated by a 20 percent increase in strength and a 100 percent increase in the Weibull modulus over that of the baseline material. A full characterization of the baseline process was completed. Material properties were found to be highly dependent on each step of the process. Several important parameters identified thus far are the starting raw materials, sinter/hot isostatic pressing cycle, powder bed, mixing methods, and sintering aid levels.

Review and assessment of the database and numerical modeling for turbine heat transfer

NASA Technical Reports Server (NTRS)

Gladden, H. J.; Simoneau, R. J.

1989-01-01

The objectives of the NASA Hot Section Technology (HOST) Turbine Heat Transfer subproject were to obtain a better understanding of the physics of the aerothermodynamic phenomena and to assess and improve the analytical methods used to predict the flow and heat transfer in high-temperature gas turbines. At the time the HOST project was initiated, an across-the-board improvement in turbine design technology was needed. A building-block approach was utilized and the research ranged from the study of fundamental phenomena and modeling to experiments in simulated real engine environments. Experimental research accounted for approximately 75 percent of the funding while the analytical efforts were approximately 25 percent. A healthy government/industry/university partnership, with industry providing almost half of the research, was created to advance the turbine heat transfer design technology base.

Workshop on Two-Phase Fluid Behavior in a Space Environment

NASA Technical Reports Server (NTRS)

Swanson, Theodore D. (Editor); Juhasz, AL (Editor); Long, W. Russ (Editor); Ottenstein, Laura (Editor)

1989-01-01

The Workshop was successful in achieving its main objective of identifying a large number of technical issues relating to the design of two-phase systems for space applications. The principal concern expressed was the need for verified analytical tools that will allow an engineer to confidently design a system to a known degree of accuracy. New and improved materials, for such applications as thermal storage and as heat transfer fluids, were also identified as major needs. In addition to these research efforts, a number of specific hardware needs were identified which will require development. These include heat pumps, low weight radiators, advanced heat pipes, stability enhancement devices, high heat flux evaporators, and liquid/vapor separators. Also identified was the need for a centralized source of reliable, up-to-date information on two-phase flow in a space environment.

Pulsed power molten salt battery

NASA Technical Reports Server (NTRS)

Argade, Shyam D.

1992-01-01

It was concluded that carbon cathodes with chlorine work well. Lithium alloy chlorine at 450 C, 1 atm given high power capability, high energy density, DC + pulsing yields 600 pulses, no initial peak, and can go to red heat without burn-up. Electrochemical performance at the cell and cell stack level out under demanding test regime. Engineering and full prototype development for advancing this technology is warranted.

Advanced Microgrid Concepts and Technologies Workshop

DTIC Science & Technology

2013-04-01

number of wind turbines (2)  Battery charge/discharge rates  Max instantaneous load (600 kW)  Required duration of energy storage (10-day episode...for components that have developed methods (gearbox, generator, sensors , small gas turbines , or reciprocating engines, etc.) o The health information...Force), superconducting wind turbine generators (DOE ARPA-E), and thermoelectric waste-heat recovery for vehicles (DOE EERE and NSF). 111 1145

Technology Evaluation for an Advanced Individual Protection System (AIPS)

DTIC Science & Technology

1992-12-01

this analysis are: time of operation, duration of thermal management, power consumed during operation, cooling/heating benefit , time between recharge...BRDEC) TOPICS: o individual power * batteries/engines/fuel cel!s POC: Wes Goodwin (NRDEC) TOPICS: * microclimate cooling e vapor compression cycles e...individual power 2.3 LITERATURE SEARCHES The literature searches began by reviewing Battelle in-house sources for useful reports. This included a

NASA's Advanced Environmental Barrier Coatings Development for SiC/SiC Ceramic Matrix Composites: Understanding Calcium Magnesium Alumino-Silicate (CMAS) Degradations and Resistance

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2014-01-01

Environmental barrier coatings (EBCs) and SiCSiC ceramic matrix composites (CMCs) systems will play a crucial role in next generation turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures with improved efficiency, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is essential to the viability and reliability of the envisioned CMC engine component applications, ensuring integrated EBC-CMC system durability and designs are achievable for successful applications of the game-changing component technologies and lifing methodologies.This paper will emphasize recent NASA environmental barrier coating developments for SiCSiC turbine airfoil components, utilizing advanced coating compositions, state-of-the-art processing methods, and combined mechanical and environment testing and durability evaluations. The coating-CMC degradations in the engine fatigue-creep and operating environments are particularly complex; one of the important coating development aspects is to better understand engine environmental interactions and coating life debits, and we have particularly addressed the effect of Calcium-Magnesium-Alumino-Silicate (CMAS) from road sand or volcano-ash deposits on the durability of the environmental barrier coating systems, and how the temperature capability, stability and cyclic life of the candidate rare earth oxide and silicate coating systems will be impacted in the presence of the CMAS at high temperatures and under simulated heat flux conditions. Advanced environmental barrier coating systems, including HfO2-Si with rare earth dopant based bond coat systems, will be discussed for the performance improvements to achieve better temperature capability and CMAS resistance for future engine operating conditions.

Embedded Thermal Control for Subsystems for Next Generation Spacecraft Applications

NASA Technical Reports Server (NTRS)

Didion, Jeffrey R.

2015-01-01

Thermal Fluids and Analysis Workshop, Silver Spring MD NCTS 21070-15. NASA, the Defense Department and commercial interests are actively engaged in developing miniaturized spacecraft systems and scientific instruments to leverage smaller cheaper spacecraft form factors such as CubeSats. This paper outlines research and development efforts among Goddard Space Flight Center personnel and its several partners to develop innovative embedded thermal control subsystems. Embedded thermal control subsystems is a cross cutting enabling technology integrating advanced manufacturing techniques to develop multifunctional intelligent structures to reduce Size, Weight and Power (SWaP) consumption of both the thermal control subsystem and overall spacecraft. Embedded thermal control subsystems permit heat acquisition and rejection at higher temperatures than state of the art systems by employing both advanced heat transfer equipment (integrated heat exchangers) and high heat transfer phenomena. The Goddard Space Flight Center Thermal Engineering Branch has active investigations seeking to characterize advanced thermal control systems for near term spacecraft missions. The embedded thermal control subsystem development effort consists of fundamental research as well as development of breadboard and prototype hardware and spaceflight validation efforts. This paper will outline relevant fundamental investigations of micro-scale heat transfer and electrically driven liquid film boiling. The hardware development efforts focus upon silicon based high heat flux applications (electronic chips, power electronics etc.) and multifunctional structures. Flight validation efforts include variable gravity campaigns and a proposed CubeSat based flight demonstration of a breadboard embedded thermal control system. The CubeSat investigation is technology demonstration will characterize in long-term low earth orbit a breadboard embedded thermal subsystem and its individual components to develop optimized operational schema.

Mechanical Properties and Durability of Advanced Environmental Barrier Coatings in Calcium-Magnesium-Alumino-Silicate Environments

NASA Technical Reports Server (NTRS)

Miladinovich, Daniel S.; Zhu, Dongming

2011-01-01

Environmental barrier coatings are being developed and tested for use with SiC/SiC ceramic matrix composite (CMC) gas turbine engine components. Several oxide and silicate based compositons are being studied for use as top-coat and intermediate layers in a three or more layer environmental barrier coating system. Specifically, the room temperature Vickers-indentation-fracture-toughness testing and high-temperature stability reaction studies with Calcium Magnesium Alumino-Silicate (CMAS or "sand") are being conducted using advanced testing techniques such as high pressure burner rig tests as well as high heat flux laser tests.

Summary of aerospace and nuclear engineering activities

NASA Technical Reports Server (NTRS)

1988-01-01

The Texas A&M Nuclear and Aerospace engineering departments have worked on five different projects for the NASA/USRA Advanced Design Program during the 1987/88 year. The aerospace department worked on two types of lunar tunnelers that would create habitable space. The first design used a heated cone to melt the lunar regolith, and the second used a conventional drill to bore its way through the crust. Both used a dump truck to get rid of waste heat from the reactor as well as excess regolith from the tunneling operation. The nuclear engineering department worked on three separate projects. The NEPTUNE system is a manned, outer-planetary explorer designed with Jupiter exploration as the baseline mission. The lifetime requirement for both reactor and power-conversion systems was twenty years. The second project undertaken for the power supply was a Mars Sample Return Mission power supply. This was designed to produce 2 kW of electrical power for seven years. The design consisted of a General Purpose Heat Source (GPHS) utilizing a Stirling engine as the power conversion unit. A mass optimization was performed to aid in overall design. The last design was a reactor to provide power for propulsion to Mars and power on the surface. The requirements of 300 kW of electrical power output and a mass of less than 10,000 Rg were set. This allowed the reactor and power conversion unit to fit within the Space Shuttle cargo bay.

Civil propulsion technology for the next twenty-five years

NASA Technical Reports Server (NTRS)

Rosen, Robert; Facey, John R.

1987-01-01

The next twenty-five years will see major advances in civil propulsion technology that will result in completely new aircraft systems for domestic, international, commuter and high-speed transports. These aircraft will include advanced aerodynamic, structural, and avionic technologies resulting in major new system capabilities and economic improvements. Propulsion technologies will include high-speed turboprops in the near term, very high bypass ratio turbofans, high efficiency small engines and advanced cycles utilizing high temperature materials for high-speed propulsion. Key fundamental enabling technologies include increased temperature capability and advanced design methods. Increased temperature capability will be based on improved composite materials such as metal matrix, intermetallics, ceramics, and carbon/carbon as well as advanced heat transfer techniques. Advanced design methods will make use of advances in internal computational fluid mechanics, reacting flow computation, computational structural mechanics and computational chemistry. The combination of advanced enabling technologies, new propulsion concepts and advanced control approaches will provide major improvements in civil aircraft.

Views on the impact of HOST

NASA Technical Reports Server (NTRS)

Esgar, J. B.; Sokolowski, Daniel E.

1989-01-01

The Hot Section Technology (HOST) Project, which was initiated by NASA Lewis Research Center in 1980 and concluded in 1987, was aimed at improving advanced aircraft engine hot section durability through better technical understanding and more accurate design analysis capability. The project was a multidisciplinary, multiorganizational, focused research effort that involved 21 organizations and 70 research and technology activities and generated approximately 250 research reports. No major hardware was developed. To evaluate whether HOST had a significant impact on the overall aircraft engine industry in the development of new engines, interviews were conducted with 41 participants in the project to obtain their views. The summarized results of these interviews are presented. Emphasis is placed on results relative to three-dimensional inelastic structural analysis, thermomechanical fatigue testing, constitutive modeling, combustor aerothermal modeling, turbine heat transfer, protective coatings, computer codes, improved engine design capability, reduced engine development costs, and the impacts on technology transfer and the industry-government partnership.

Development Status and Performance Comparisons of Environmental Barrier Coating Systems for SiCSiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan

2016-01-01

Environmental barrier coatings (EBC) and SiCSiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft turbine engine systems, because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. This paper presents current NASA EBC-CMC development emphases including: the coating composition and processing improvements, laser high heat flux-thermal gradient thermo-mechanical fatigue - environmental testing methodology development, and property evaluations for next generation EBC-CMC systems. EBCs processed with various deposition techniques including Plasma Spray, Electron Beam - Physical Vapor Deposition, and Plasma Spray Physical Vapor Deposition (PS-PVD) will be particularly discussed. The testing results and demonstrations of advanced EBCs-CMCs in complex simulated engine thermal gradient cyclic fatigue, oxidizing-steam and CMAS environments will help provide insights into the coating development strategies to meet long-term engine component durability goals.

Tribological properties of Ag/Ti films on Al2O3 ceramic substrates

NASA Technical Reports Server (NTRS)

Dellacorte, Christopher; Pepper, Stephen V.; Honecy, Frank S.

1991-01-01

Ag solid lubricant films, with a thin Ti interlayer for enhanced adhesion, were sputter deposited on Al2O3 substrate disks to reduce friction and wear. The dual Ag/Ti films were tested at room temperature in a pin-on-disk tribometer sliding against bare, uncoated Al2O3 pins under a 4.9 N load at a sliding velocity of 1 m/s. The Ag/Ti films reduced the friction coefficient by 50 percent to about 0.41 compared to unlubricated baseline specimens. Pin wear was reduced by a factor of 140 and disk wear was reduced by a factor of 2.5 compared to the baseline. These films retain their good tribological properties including adhesion after heat treatments at 850 C and thus may be able to lubricate over a wide temperature range. This lubrication technique is applicable to space lubrication, advanced heat engines, and advanced transportation systems.

Method for controlling exhaust gas heat recovery systems in vehicles

DOEpatents

Spohn, Brian L.; Claypole, George M.; Starr, Richard D

2013-06-11

A method of operating a vehicle including an engine, a transmission, an exhaust gas heat recovery (EGHR) heat exchanger, and an oil-to-water heat exchanger providing selective heat-exchange communication between the engine and transmission. The method includes controlling a two-way valve, which is configured to be set to one of an engine position and a transmission position. The engine position allows heat-exchange communication between the EGHR heat exchanger and the engine, but does not allow heat-exchange communication between the EGHR heat exchanger and the oil-to-water heat exchanger. The transmission position allows heat-exchange communication between the EGHR heat exchanger, the oil-to-water heat exchanger, and the engine. The method also includes monitoring an ambient air temperature and comparing the monitored ambient air temperature to a predetermined cold ambient temperature. If the monitored ambient air temperature is greater than the predetermined cold ambient temperature, the two-way valve is set to the transmission position.

The design and fabrication of a Stirling engine heat exchanger module with an integral heat pipe

NASA Technical Reports Server (NTRS)

Schreiber, Jeffrey G.

1988-01-01

The conceptual design of a free-piston Stirling Space Engine (SSE) intended for space power applications has been generated. The engine was designed to produce 25 kW of electric power with heat supplied by a nuclear reactor. A novel heat exchanger module was designed to reduce the number of critical joints in the heat exchanger assembly while also incorporating a heat pipe as the link between the engine and the heat source. Two inexpensive verification tests are proposed. The SSE heat exchanger module is described and the operating conditions for the module are outlined. The design process of the heat exchanger modules, including the sodium heat pipe, is briefly described. Similarities between the proposed SSE heat exchanger modules and the LeRC test modules for two test engines are presented. The benefits and weaknesses of using a sodium heat pipe to transport heat to a Stirling engine are discussed. Similarly, the problems encountered when using a true heat pipe, as opposed to a more simple reflux boiler, are described. The instruments incorporated into the modules and the test program are also outlined.

Steam bottoming cycle for an adiabatic diesel engine

NASA Technical Reports Server (NTRS)

Poulin, E.; Demier, R.; Krepchin, I.; Walker, D.

1984-01-01

Steam bottoming cycles using adiabatic diesel engine exhaust heat which projected substantial performance and economic benefits for long haul trucks were studied. Steam cycle and system component variables, system cost, size and performance were analyzed. An 811 K/6.90 MPa state of the art reciprocating expander steam system with a monotube boiler and radiator core condenser was selected for preliminary design. The costs of the diesel with bottoming system (TC/B) and a NASA specified turbocompound adiabatic diesel with aftercooling with the same total output were compared, the annual fuel savings less the added maintenance cost was determined to cover the increase initial cost of the TC/B system in a payback period of 2.3 years. Steam bottoming system freeze protection strategies were developed, technological advances required for improved system reliability are considered and the cost and performance of advanced systes are evaluated.

Advances in cryogenic engineering. Volume 27 - Proceedings of the Cryogenic Engineering Conference, San Diego, CA, August 11-14, 1981

NASA Technical Reports Server (NTRS)

Fast, R. W. (Editor)

1982-01-01

Applications of superconductivity are considered, taking into account MHD and fusion, generators, transformers, transmission lines, magnets for physics, cryogenic techniques, electrtronics, and aspects of magnet stability. Advances related to heat transfer in He I are discussed along with subjects related to theat transfer in He II, refrigeration of superconducting systems, refrigeration and liquefaction, dilution and magnetic refrigerators, refrigerators for space applications, mass transfer and flow phenomena, and the properties of fluids. Developments related to cryogenic applications are also explored, giving attention to bulk storage and transfer of cryogenic fluids, liquefied natural gas operations, space science and technology, and cryopumping. Topics related to cryogenic instrumentation and controls include the production and use of high grade silicon diode temperature sensors, the choice of strain gages for use in a large superconducting alternator, microprocessor control of cryogenic pressure, and instrumentation, data acquisition and reduction for a large spaceborne helium dewar.

Development of the Advanced Energy Design Guide for K-12 Schools -- 50% Energy Savings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonnema, E.; Leach, M.; Pless, S.

2013-02-01

This Technical Support Document (TSD) describes the process and methodology for the development of the Advanced Energy Design Guide for K-12 School Buildings: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-K12) (ASHRAE et al. 2011a). The AEDG-K12 provides recommendations for achieving 50% whole-building energy savings in K-12 schools over levels achieved by following ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings (Standard 90.1-2004) (ASHRAE 2004b). The AEDG-K12 was developed in collaboration with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of Northmore » America (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy (DOE).« less

ASME Code Efforts Supporting HTGRs

DOE Office of Scientific and Technical Information (OSTI.GOV)

D.K. Morton

2010-09-01

In 1999, an international collaborative initiative for the development of advanced (Generation IV) reactors was started. The idea behind this effort was to bring nuclear energy closer to the needs of sustainability, to increase proliferation resistance, and to support concepts able to produce energy (both electricity and process heat) at competitive costs. The U.S. Department of Energy has supported this effort by pursuing the development of the Next Generation Nuclear Plant, a high temperature gas-cooled reactor. This support has included research and development of pertinent data, initial regulatory discussions, and engineering support of various codes and standards development. This reportmore » discusses the various applicable American Society of Mechanical Engineers (ASME) codes and standards that are being developed to support these high temperature gascooled reactors during construction and operation. ASME is aggressively pursuing these codes and standards to support an international effort to build the next generation of advanced reactors so that all can benefit.« less

ASME Code Efforts Supporting HTGRs

DOE Office of Scientific and Technical Information (OSTI.GOV)

D.K. Morton

2011-09-01

In 1999, an international collaborative initiative for the development of advanced (Generation IV) reactors was started. The idea behind this effort was to bring nuclear energy closer to the needs of sustainability, to increase proliferation resistance, and to support concepts able to produce energy (both electricity and process heat) at competitive costs. The U.S. Department of Energy has supported this effort by pursuing the development of the Next Generation Nuclear Plant, a high temperature gas-cooled reactor. This support has included research and development of pertinent data, initial regulatory discussions, and engineering support of various codes and standards development. This reportmore » discusses the various applicable American Society of Mechanical Engineers (ASME) codes and standards that are being developed to support these high temperature gascooled reactors during construction and operation. ASME is aggressively pursuing these codes and standards to support an international effort to build the next generation of advanced reactors so that all can benefit.« less

ASME Code Efforts Supporting HTGRs

DOE Office of Scientific and Technical Information (OSTI.GOV)

D.K. Morton

2012-09-01

In 1999, an international collaborative initiative for the development of advanced (Generation IV) reactors was started. The idea behind this effort was to bring nuclear energy closer to the needs of sustainability, to increase proliferation resistance, and to support concepts able to produce energy (both electricity and process heat) at competitive costs. The U.S. Department of Energy has supported this effort by pursuing the development of the Next Generation Nuclear Plant, a high temperature gas-cooled reactor. This support has included research and development of pertinent data, initial regulatory discussions, and engineering support of various codes and standards development. This reportmore » discusses the various applicable American Society of Mechanical Engineers (ASME) codes and standards that are being developed to support these high temperature gascooled reactors during construction and operation. ASME is aggressively pursuing these codes and standards to support an international effort to build the next generation of advanced reactors so that all can benefit.« less

Research trend in thermally stimulated current method for development of materials and devices in Japan

NASA Astrophysics Data System (ADS)

Iwamoto, Mitsumasa; Taguchi, Dai

2018-03-01

Thermally stimulated current (TSC) measurement is widely used in a variety of research fields, i.e., physics, electronics, electrical engineering, chemistry, ceramics, and biology. TSC is short-circuit current that flows owing to the displacement of charges in samples during heating. TSC measurement is very simple, but TSC curves give very important information on charge behaviors. In the 1970s, TSC measurement contributed greatly to the development of electrical insulation engineering, semiconductor device technology, and so forth. Accordingly, the TSC experimental technique and its analytical method advanced. Over the past decades, many new molecules and advanced functional materials have been discovered and developed. Along with this, TSC measurement has attracted much attention in industries and academic laboratories as a way of characterizing newly discovered materials and devices. In this review, we report the latest research trend in the TSC method for the development of materials and devices in Japan.

Technical Support Document: Development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings - 50% Energy Savings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonnema, E.; Leach, M.; Pless, S.

2013-06-01

This Technical Support Document describes the process and methodology for the development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-MBBR) ASHRAE et al. (2011b). The AEDG-MBBR is intended to provide recommendations for achieving 50% whole-building energy savings in retail stores over levels achieved by following ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings (Standard 90.1-2004) (ASHRAE 2004b). The AEDG-MBBR was developed in collaboration with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), themore » Illuminating Engineering Society of North America (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy.« less

Technical Support Document: Development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings - 50% Energy Savings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonnema, Eric; Leach, Matt; Pless, Shanti

2013-06-05

This Technical Support Document describes the process and methodology for the development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-MBBR) ASHRAE et al. (2011b). The AEDG-MBBR is intended to provide recommendations for achieving 50% whole-building energy savings in retail stores over levels achieved by following ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings (Standard 90.1-2004) (ASHRAE 2004b). The AEDG-MBBR was developed in collaboration with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), themore » Illuminating Engineering Society of North America (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy.« less

Hypersonic Engine Leading Edge Experiments in a High Heat Flux, Supersonic Flow Environment

NASA Technical Reports Server (NTRS)

Gladden, Herbert J.; Melis, Matthew E.

1994-01-01

A major concern in advancing the state-of-the-art technologies for hypersonic vehicles is the development of an aeropropulsion system capable of withstanding the sustained high thermal loads expected during hypersonic flight. Three aerothermal load related concerns are the boundary layer transition from laminar to turbulent flow, articulating panel seals in high temperature environments, and strut (or cowl) leading edges with shock-on-shock interactions. A multidisciplinary approach is required to address these technical concerns. A hydrogen/oxygen rocket engine heat source has been developed at the NASA Lewis Research Center as one element in a series of facilities at national laboratories designed to experimentally evaluate the heat transfer and structural response of the strut (or cowl) leading edge. A recent experimental program conducted in this facility is discussed and related to cooling technology capability. The specific objective of the experiment discussed is to evaluate the erosion and oxidation characteristics of a coating on a cowl leading edge (or strut leading edge) in a supersonic, high heat flux environment. Heat transfer analyses of a similar leading edge concept cooled with gaseous hydrogen is included to demonstrate the complexity of the problem resulting from plastic deformation of the structures. Macro-photographic data from a coated leading edge model show progressive degradation over several thermal cycles at aerothermal conditions representative of high Mach number flight.

High-Speed, High-Temperature Finger Seal Test Evaluated

NASA Technical Reports Server (NTRS)

Proctor, Margaret P.

2003-01-01

A finger seal, designed and fabricated by Honeywell Engines, Systems and Services, was tested at the NASA Glenn Research Center at surface speeds up to 1200 ft/s, air temperatures up to 1200 F, and pressures across the seal of 75 psid. These are the first test results obtained with NASA s new High-Temperature, High-Speed Turbine Seal Test Rig (see the photograph). The finger seal is an innovative design recently patented by AlliedSignal Engines, which has demonstrated considerably lower leakage than commonly used labyrinth seals and is considerably cheaper than brush seals. The cost to produce finger seals is estimated to be about half of the cost to produce brush seals. Replacing labyrinth seals with fingers seals at locations that have high-pressure drops in gas turbine engines, typically main engine and thrust seals, can reduce air leakage at each location by 50 percent or more. This directly results in a 0.7- to 1.4-percent reduction in specific fuel consumption and a 0.35- to 0.7-percent reduction in direct operating costs . Because the finger seal is a contacting seal, this testing was conducted to address concerns about its heat generation and life capability at the higher speeds and temperatures required for advanced engines. The test results showed that the seal leakage and wear performance are acceptable for advanced engines.

Dual Nozzle Aerodynamic and Cooling Analysis Study.

DTIC Science & Technology

1981-02-27

program and to the aerodynamic model computer program. This pro - cedure was used to define two secondary nozzle contours for the baseline con - figuration...both the dual-throat and dual-expander con - cepts. Advanced analytical techniques were utilized to provide quantitative estimates of the bleed flow...preliminary heat transfer analysis of both con - cepts, and (5) engineering analysis of data from the NASA/MSFC hot-fire testing of a dual-throat

Code for Multiblock CFD and Heat-Transfer Computations

NASA Technical Reports Server (NTRS)

Fabian, John C.; Heidmann, James D.; Lucci, Barbara L.; Ameri, Ali A.; Rigby, David L.; Steinthorsson, Erlendur

2006-01-01

The NASA Glenn Research Center General Multi-Block Navier-Stokes Convective Heat Transfer Code, Glenn-HT, has been used extensively to predict heat transfer and fluid flow for a variety of steady gas turbine engine problems. Recently, the Glenn-HT code has been completely rewritten in Fortran 90/95, a more object-oriented language that allows programmers to create code that is more modular and makes more efficient use of data structures. The new implementation takes full advantage of the capabilities of the Fortran 90/95 programming language. As a result, the Glenn-HT code now provides dynamic memory allocation, modular design, and unsteady flow capability. This allows for the heat-transfer analysis of a full turbine stage. The code has been demonstrated for an unsteady inflow condition, and gridding efforts have been initiated for a full turbine stage unsteady calculation. This analysis will be the first to simultaneously include the effects of rotation, blade interaction, film cooling, and tip clearance with recessed tip on turbine heat transfer and cooling performance. Future plans call for the application of the new Glenn-HT code to a range of gas turbine engine problems of current interest to the heat-transfer community. The new unsteady flow capability will allow researchers to predict the effect of unsteady flow phenomena upon the convective heat transfer of turbine blades and vanes. Work will also continue on the development of conjugate heat-transfer capability in the code, where simultaneous solution of convective and conductive heat-transfer domains is accomplished. Finally, advanced turbulence and fluid flow models and automatic gridding techniques are being developed that will be applied to the Glenn-HT code and solution process.

Combination solar photovoltaic heat engine energy converter

NASA Technical Reports Server (NTRS)

Chubb, Donald L.

1987-01-01

A combination solar photovoltaic heat engine converter is proposed. Such a system is suitable for either terrestrial or space power applications. The combination system has a higher efficiency than either the photovoltaic array or the heat engine alone can attain. Advantages in concentrator and radiator area and receiver mass of the photovoltaic heat engine system over a heat-engine-only system are estimated. A mass and area comparison between the proposed space station organic Rankine power system and a combination PV-heat engine system is made. The critical problem for the proposed converter is the necessity for high temperature photovoltaic array operation. Estimates of the required photovoltaic temperature are presented.

Thermal Conductivity Change Kinetics of Ceramic Thermal Barrier Coatings Determined by the Steady-State Laser Heat Flux Technique

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2000-01-01

A steady-state laser heat flux technique has been developed at the NASA Glenn Research Center at Lewis Field to obtain critical thermal conductivity data of ceramic thermal barrier coatings under the temperature and thermal gradients that are realistically expected to be encountered in advanced engine systems. In this study, thermal conductivity change kinetics of a plasma-sprayed, 254-mm-thick ZrO2-8 wt % Y2O3 ceramic coating were obtained at high temperatures. During the testing, the temperature gradients across the coating system were carefully measured by the surface and back pyrometers and an embedded miniature thermocouple in the substrate. The actual heat flux passing through the coating system was determined from the metal substrate temperature drop (measured by the embedded miniature thermocouple and the back pyrometer) combined with one-dimensional heat transfer models.

Design Considerations for Clean QED Fusion Propulsion Systems

NASA Astrophysics Data System (ADS)

Bussard, Robert W.; Jameson, Lorin W.

1994-07-01

The direct production of electric power appears possible from fusion reactions between fuels whose products consist solely of charged particles and thus do not present radiation hazards from energetic neutron production, as do reactions involving deuteron-bearing fuels. Among these are the fuels p, 11B, 3He, and 6Li. All of these can be ``burned'' in inertial-electrostatic-fusion (IEF) devices to power QED fusion-electric rocket engines. These IEF sources provide direct-converted electrical power at high voltage (MeV) to drive e-beams for efficient propellant heating to extreme temperatures, with resulting high specific impulse performance capabilities. IEF/QED engine systems using p11B can outperform all other advanced concepts for controlled fusion propulsion by 2-3 orders of magnitude, while 6Li6Li fusion yields one order of magnitude less advance. Either of these fusion rocket propulsion systems can provide very rapid transit for solar system missions, with high payload fractions in single-stage vehicles. The 3He3He reaction can not be used practically for direct electric conversion because of the wide spread in energy of its fusion products. However, it may eventually prove useful for thermal/electrical power generation in central station power plants, or for direct-fusion-product (DFP) propellant heatingin advanced deep-space rocket engines.

Cryogenic hydrogen-induced air liquefaction technologies

NASA Technical Reports Server (NTRS)

Escher, William J. D.

1990-01-01

Extensively utilizing a special advanced airbreathing propulsion archives database, as well as direct contacts with individuals who were active in the field in previous years, a technical assessment of cryogenic hydrogen-induced air liquefaction, as a prospective onboard aerospace vehicle process, was performed and documented. The resulting assessment report is summarized. Technical findings are presented relating the status of air liquefaction technology, both as a singular technical area, and also that of a cluster of collateral technical areas including: compact lightweight cryogenic heat exchangers; heat exchanger atmospheric constituents fouling alleviation; para/ortho hydrogen shift conversion catalysts; hydrogen turbine expanders, cryogenic air compressors and liquid air pumps; hydrogen recycling using slush hydrogen as heat sink; liquid hydrogen/liquid air rocket-type combustion devices; air collection and enrichment systems (ACES); and technically related engine concepts.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zaupa, M., E-mail: matteo.zaupa@igi.cnr.it; Consorzio RFX, Corso Stati Uniti 4, Padova 35127; Sartori, E.

Megavolt ITER Injector Concept Advancement is the full scale prototype of the heating and current drive neutral beam injectors for ITER, to be built at Consorzio RFX (Padova). The engineering design of its components is challenging: the total heat loads they will be subjected to (expected between 2 and 19 MW), the high heat fluxes (up to 20 MW/m{sup 2}), and the beam pulse duration up to 1 h, set demanding requirements for reliable active cooling circuits. In support of the design, the thermo-hydraulic behavior of each cooling circuit under steady state condition has been investigated by using one-dimensional models.more » The final results, obtained considering a number of optimizations for the cooling circuits, show that all the requirements in terms of flow rate, temperature, and pressure drop are properly fulfilled.« less

Thermal Energy Conversion Branch

NASA Technical Reports Server (NTRS)

Bielozer, Matthew C.; Schreiber, Jeffrey, G.; Wilson, Scott D.

2004-01-01

The Thermal Energy Conversion Branch (5490) leads the way in designing, conducting, and implementing research for the newest thermal systems used in space applications at the NASA Glenn Research Center. Specifically some of the most advanced technologies developed in this branch can be broken down into four main areas: Dynamic Power Systems, Primary Solar Concentrators, Secondary Solar Concentrators, and Thermal Management. Work was performed in the Dynamic Power Systems area, specifically the Stirling Engine subdivision. Today, the main focus of the 5490 branch is free-piston Stirling cycle converters, Brayton cycle nuclear reactors, and heat rejection systems for long duration mission spacecraft. All space exploring devices need electricity to operate. In most space applications, heat energy from radioisotopes is converted to electrical power. The Radioisotope Thermoelectric Generator (RTG) already supplies electricity for missions such as the Cassini Spacecraft. The focus of today's Stirling research at GRC is aimed at creating an engine that can replace the RTG. The primary appeal of the Stirling engine is its high system efficiency. Because it is so efficient, the Stirling engine will significantly reduce the plutonium fuel mission requirements compared to the RTG. Stirling is also being considered for missions such as the lunar/Mars bases and rovers. This project has focused largely on Stirling Engines of all types, particularly the fluidyne liquid piston engine. The fluidyne was developed by Colin D. West. This engine uses the same concepts found in any type of Stirling engine, with the exception of missing mechanical components. All the working components are fluid. One goal was to develop and demonstrate a working Stirling Fluidyne Engine at the 2nd Annual International Energy Conversion Engineering Conference in Providence, Rhode Island.

Rankine cycle waste heat recovery system

DOEpatents

Ernst, Timothy C.; Nelson, Christopher R.

2015-09-22

A waste heat recovery (WHR) system connects a working fluid to fluid passages formed in an engine block and/or a cylinder head of an internal combustion engine, forming an engine heat exchanger. The fluid passages are formed near high temperature areas of the engine, subjecting the working fluid to sufficient heat energy to vaporize the working fluid while the working fluid advantageously cools the engine block and/or cylinder head, improving fuel efficiency. The location of the engine heat exchanger downstream from an EGR boiler and upstream from an exhaust heat exchanger provides an optimal position of the engine heat exchanger with respect to the thermodynamic cycle of the WHR system, giving priority to cooling of EGR gas. The configuration of valves in the WHR system provides the ability to select a plurality of parallel flow paths for optimal operation.

Pool boiler heat transport system for a 25 kWe advanced Stirling conversion system

NASA Astrophysics Data System (ADS)

Anderson, W. G.; Rosenfeld, J. H.; Saaski, E. L.; Noble, J.; Tower, L.

Experiments to determine alkali metal/enhanced surface combinations that have stable boiling at the temperatures and heat fluxes that occur in the Stirling engine are reported. Two enhanced surfaces and two alkali metal working fluids were evaluated. The enhanced surfaces were an EDM hole covered surface and a sintered-powder-metal porous layer surface. The working fluids tested were potassium and eutectic sodium-potasium alloy (NaK), both with and without undissolved noncondensible gas. Noncondensible gas (He and Xe) was added to the system to provide gas in the nucleation sites, preventing quenching of the sites. The experiments demonstrated the potential of an alkali metal pool boiler heat transport system for use in a solar-powered Stirling engine. The most favorable fluid/surface combination tested was NaK boiling on a -100 +140 mesh 304L stainless steel sintered porous layer with no undissolved noncondensible gas. This combination provided stable, high-performance boiling at the operating temperature of 700 C. Heat fluxes into the system ranged from 10 to 50 W/sq cm. The transition from free convection to nucleate boiling occurred at temperatures near 540 C. Based on these experiments, a pool boiler was designed for a full-scale 25-kWe Stirling system.

Pool boiler heat transport system for a 25 kWe advanced Stirling conversion system

NASA Technical Reports Server (NTRS)

Anderson, W. G.; Rosenfeld, J. H.; Saaski, E. L.; Noble, J.; Tower, L.

1990-01-01

Experiments to determine alkali metal/enhanced surface combinations that have stable boiling at the temperatures and heat fluxes that occur in the Stirling engine are reported. Two enhanced surfaces and two alkali metal working fluids were evaluated. The enhanced surfaces were an EDM hole covered surface and a sintered-powder-metal porous layer surface. The working fluids tested were potassium and eutectic sodium-potasium alloy (NaK), both with and without undissolved noncondensible gas. Noncondensible gas (He and Xe) was added to the system to provide gas in the nucleation sites, preventing quenching of the sites. The experiments demonstrated the potential of an alkali metal pool boiler heat transport system for use in a solar-powered Stirling engine. The most favorable fluid/surface combination tested was NaK boiling on a -100 +140 mesh 304L stainless steel sintered porous layer with no undissolved noncondensible gas. This combination provided stable, high-performance boiling at the operating temperature of 700 C. Heat fluxes into the system ranged from 10 to 50 W/sq cm. The transition from free convection to nucleate boiling occurred at temperatures near 540 C. Based on these experiments, a pool boiler was designed for a full-scale 25-kWe Stirling system.

Dual-throat thruster thermal model

NASA Technical Reports Server (NTRS)

Ewen, R. L.; Obrien, C. J.; Matthews, L. W.

1986-01-01

The dual-throat engine is one of the dual nozzle engine concepts studied for advanced space transportation applications. It provides a thrust change and an in-flight area ratio change through the use of two concentric combustors with their throats arranged in series. Test results are presented for a dual throat thruster burning gaseous oxygen and hydrogen at primary (inner) chamber pressures from 380 to 680 psia. Heat flux profiles were obtained from calorimetric cooling channels in the inner nozzle, outer or secondary chamber and the tip of the inner nozzle. Data were obtained for two nozzle spacings over a chamber pressure ratio (secondary/primary) range of 0.45 to 0.83 with both chambers firing (Mode I). Fluxes near the end of the inner nozzle were significantly higher than in Mode II when only the inner chamber was fired, due to the flow separation and recirculation caused by the back pressure imposed by the secondary chamber. As the pressure ratio increased, these heat fluxes increased and the region of high heat flux relative to Mode II extended farther upstream. The use of the gaseous hydrogen bleed flow in the secondary chamber to control heat fluxes in the primary plume attachment region was investigated in Mode II testing. A thermal model of a dual throat thruster was developed and upgraded using the experimental data.

Black holes in massive gravity as heat engines

NASA Astrophysics Data System (ADS)

Hendi, S. H.; Eslam Panah, B.; Panahiyan, S.; Liu, H.; Meng, X.-H.

2018-06-01

The paper at hand studies the heat engine provided by black holes in the presence of massive gravity. The main motivation is to investigate the effects of massive gravity on different properties of the heat engine. It will be shown that massive gravity parameters modify the efficiency of engine on a significant level. Furthermore, it will be pointed out that it is possible to have a heat engine for non-spherical black holes in massive gravity, and therefore, we will study the effects of horizon topology on the properties of heat engine. Surprisingly, it will be shown that the highest efficiency for the heat engine belongs to black holes with the hyperbolic horizon, while the lowest one belongs to the spherical black holes.

Advanced Propfan Engine Technology (APET) and Single-rotation Gearbox/Pitch Change Mechanism

NASA Technical Reports Server (NTRS)

Sargisson, D. F.

1985-01-01

The projected performance, in the 1990's time period, of the equivalent technology level high bypass ratio turbofan powered aircraft (at the 150 passenger size) is compared with advanced turboprop propulsion systems. Fuel burn analysis, economic analysis, and pollution (noise, emissions) estimates were made. Three different cruise Mach numbers were investigated for both the turbofan and the turboprop systems. Aerodynamic design and performance estimates were made for nacelles, inlets, and exhaust systems. Air to oil heat exchangers were investigated for oil cooling advanced gearboxes at the 12,500 SHP level. The results and conclusions are positive in that high speed turboprop aircraft will exhibit superior fuel burn characteristics and lower operating costs when compared with equivalent technology turbofan aircraft.

A 1987 overview of free-piston Stirling technology for space power application

NASA Technical Reports Server (NTRS)

Slaby, Jack G.; Alger, Donald L.

1987-01-01

An overview is presented of the NASA Lewis Research Center free-piston Stirling engine activities directed toward space-power application. NASA Lewis serves as the project office to manage the newly initiated NASA SP-100 Advanced Technology Program. One of the major elements of this five-year program is the development of advanced power conversion concepts of which the Stirling cycle is a viable growth candidate. Under this program the status of the 25 kWe opposed-piston Space Power Demonstrator Engine (SPDE) is presented. Included in the SPDE discussion are comparisons between predicted and experimental engine performance, enhanced performance resulting from regenerator modification, increased operating stroke brought about by isolating the gas bearing flow between the displacer and power piston, identifying excessive energy losses and recommending corrective action, and a better understanding of linear alternator design and operation. Technology work is also conducted on heat exchanger concepts, both design and fabrication. Design parameters and conceptual design features are also presented for a 25 kWe, single-cylinder free-piston Stirling space-power converter.

Aerodynamic Flow Field Measurements for Automotive Systems

NASA Technical Reports Server (NTRS)

Hepner, Timothy E.

1999-01-01

The design of a modern automotive air handling system is a complex task. The system is required to bring the interior of the vehicle to a comfortable level in as short a time as possible. A goal of the automotive industry is to predict the interior climate of an automobile using advanced computational fluid dynamic (CFD) methods. The development of these advanced prediction tools will enable better selection of engine and accessory components. The goal of this investigation was to predict methods used by the automotive industry. To accomplish this task three separate experiments were performed. The first was a laboratory setup where laser velocimeter (LV) flow field measurements were made in the heating and air conditioning unit of a Ford Windstar. The second involved flow field measurements in the engine compartment of a Ford Explorer, with the engine running idle. The third mapped the flow field exiting the center dashboard panel vent inside the Explorer, while the circulating fan operated at 14 volts. All three experiments utilized full-coincidence three-component LV systems. This enabled the mean and fluctuating velocities to be measured along with the Reynolds stress terms.

Numerical Propulsion System Simulation: A Common Tool for Aerospace Propulsion Being Developed

NASA Technical Reports Server (NTRS)

Follen, Gregory J.; Naiman, Cynthia G.

2001-01-01

The NASA Glenn Research Center is developing an advanced multidisciplinary analysis environment for aerospace propulsion systems called the Numerical Propulsion System Simulation (NPSS). This simulation is initially being used to support aeropropulsion in the analysis and design of aircraft engines. NPSS provides increased flexibility for the user, which reduces the total development time and cost. It is currently being extended to support the Aviation Safety Program and Advanced Space Transportation. NPSS focuses on the integration of multiple disciplines such as aerodynamics, structure, and heat transfer with numerical zooming on component codes. Zooming is the coupling of analyses at various levels of detail. NPSS development includes using the Common Object Request Broker Architecture (CORBA) in the NPSS Developer's Kit to facilitate collaborative engineering. The NPSS Developer's Kit will provide the tools to develop custom components and to use the CORBA capability for zooming to higher fidelity codes, coupling to multidiscipline codes, transmitting secure data, and distributing simulations across different platforms. These powerful capabilities will extend NPSS from a zero-dimensional simulation tool to a multifidelity, multidiscipline system-level simulation tool for the full life cycle of an engine.

Study, optimization, and design of a laser heat engine. [for satellite applications

NASA Technical Reports Server (NTRS)

Taussig, R. T.; Cassady, P. E.; Zumdieck, J. F.

1978-01-01

Laser heat engine concepts, proposed for satellite applications, are analyzed to determine which engine concept best meets the requirements of high efficiency (50 percent or better), continuous operation in space using near-term technology. The analysis of laser heat engines includes the thermodynamic cycles, engine design, laser power sources, collector/concentrator optics, receiving windows, absorbers, working fluids, electricity generation, and heat rejection. Specific engine concepts, optimized according to thermal efficiency, are rated by their technological availability and scaling to higher powers. A near-term experimental demonstration of the laser heat engine concept appears feasible utilizing an Otto cycle powered by CO2 laser radiation coupled into the engine through a diamond window. Higher cycle temperatures, higher efficiencies, and scalability to larger sizes appear to be achievable from a laser heat engine design based on the Brayton cycle and powered by a CO laser.

High heat flux measurements and experimental calibrations/characterizations

NASA Technical Reports Server (NTRS)

Kidd, Carl T.

1992-01-01

Recent progress in techniques employed in the measurement of very high heat-transfer rates in reentry-type facilities at the Arnold Engineering Development Center (AEDC) is described. These advances include thermal analyses applied to transducer concepts used to make these measurements; improved heat-flux sensor fabrication methods, equipment, and procedures for determining the experimental time response of individual sensors; performance of absolute heat-flux calibrations at levels above 2,000 Btu/cu ft-sec (2.27 kW/cu cm); and innovative methods of performing in-situ run-to-run characterizations of heat-flux probes installed in the test facility. Graphical illustrations of the results of extensive thermal analyses of the null-point calorimeter and coaxial surface thermocouple concepts with application to measurements in aerothermal test environments are presented. Results of time response experiments and absolute calibrations of null-point calorimeters and coaxial thermocouples performed in the laboratory at intermediate to high heat-flux levels are shown. Typical AEDC high-enthalpy arc heater heat-flux data recently obtained with a Calspan-fabricated null-point probe model are included.

Solar Stirling system development

NASA Technical Reports Server (NTRS)

Stearns, J. W., Jr.; Won, Y. S.; Poon, P. T.; Das, R.; Chow, E. Y.

1979-01-01

A low-cost, high-efficiency dish-Stirling solar thermal-electric power system is being developed for test in 1981. System components are the solar concentrator, receiver, fossil fuel combustor, thermal energy storage (TES), engine-generator, and power processing. System conceptualization is completed and design is in progress. Two receiver alternatives are being evaluated, a direct-coupled receiver-engine configuration with no TES and a heat pipe receiver with TES. System cost projections are being made. Goals for the system development task are (1) to develop an advanced dish-Stirling technology, utilizing a team of industrial contractors, (2) to demonstrate that technology at the system level, and (3) to determine how to achieve low production cost.

Development of high temperature liquid lubricants for low-heat rejection heavy duty diesel engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiczynski, T.A.; Marolewski, T.A.

1993-03-01

Objective was to develop a liquid lubricant that will allow advanced diesel engines to operate at top ring reversal temperatures approaching 500 C and lubricant sump temperatures approaching 250 C. Base stock screening showed that aromatic esters and diesters has the lowest deposit level, compared to polyol esters, poly-alpha-olefins, or refined mineral oil of comparable viscosity. Classical aryl and alkyl ZDP antiwear additives are ineffective in reducing wear with aromatic esters; the phosphate ester was a much better antiwear additive, and polyol esters are more amenable to ZDP treatment. Zeolites and clays were evaluated for filtration.

Fuel savings with conventional hot water space heating systems by incorporating a natural gas powered heat pump. Preliminary project: Development of heat pump technology

NASA Astrophysics Data System (ADS)

Vanheyden, L.; Evertz, E.

1980-12-01

Compression type air/water heat pumps were developed for domestic heating systems rated at 20 to 150 kW. The heat pump is driven either by a reciprocating piston or rotary piston engine modified to operate on natural gas. Particular features of natural gas engines as prime movers, such as waste heat recovery and variable speed, are stressed. Two systems suitable for heat pump operation were selected from among five different mass produced car engines and were modified to incorporate reciprocating piston compressor pairs. The refrigerants used are R 12 and R 22. Test rig data transferred to field conditions show that the fuel consumption of conventional boilers can be reduced by 50% and more by the installation of engine driven heat pumps. Pilot heat pumps based on a 1,600 cc reciprocating piston engine were built for heating four two-family houses. Pilot pump operation confirms test rig findings. The service life of rotary piston and reciprocating piston engines was investigated. The tests reveal characteristic curves for reciprocating piston engines and include exhaust composition measurements.

Development of a high-efficiency, gas-fired, absorption heat pump for residental and small-commercial applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillips, B.A.

1990-09-01

The purpose of the total project is to develop a gas-fired absorption heat pump for residential and small-commercial applications that will produce at least 1.6 Btu of heating and 0.7 Btu of cooling per Btu of heat content in the gas being burned. The primary technology advances that can be used to attain the new goals are higher efficiency cycles, increased flue efficiency, and better fluids. Flue efficiency technology is well developed, and fan-assisted combustion systems with condensing heat exchangers can limit flue and insulation losses to the 10% range. If this 10% loss assumption is made, the resulting targetmore » cycle COPs are 1.78 in heating mode and 0.78 in cooling mode at the ARI rating conditions. The objective of Phase 1 was to analyze working fluids and absorption-cycle concepts that are capable of performing at the target COPs and are potentially competitive with existing space-conditioning products in cost, operating life, and reliability. Six advanced cycles were evaluated with ammonia/water as the fluid pair. Then additional analysis was performed with other fluid pairs to determine whether cycle ranking would change depending on which fluid was used. It was concluded that the preferred cycle/fluid was the generator-absorber heat exchange (GAX) cycle using ammonia/water as the fluid pair. A cost estimate made by an independent manufacturing engineering firm for a residential heat pump based on the cycle/fluid combination determined that the GAX heat pump could be cost competitive with existing products. 20 refs., 28 figs., 2 tabs.« less

Performance characteristics of a combination solar photovoltaic heat engine energy converter

NASA Technical Reports Server (NTRS)

Chubb, Donald L.

1987-01-01

A combination solar photovoltaic heat engine converter is proposed. Such a system is suitable for either terrestrial or space power applications. The combination system has a higher efficiency than either the photovoltaic array or the heat engine alone can attain. Advantages in concentrator and radiator area and receiver mass of the photovoltaic heat engine system over a heat-engine-only system are estimated. A mass and area comparison between the proposed space station organic Rankine power system and a combination PV-heat engine system is made. The critical problem for the proposed converter is the necessity for high temperature photovoltaic array operation. Estimates of the required photovoltaic temperature are presented.

Cook/chill foodservice system with a microwave oven: aerobic plate counts from beef loaf, potatoes and frozen green beans.

PubMed

Dahl, C A; Matthews, M E; Marth, E H

1980-06-01

The purpose was to evaluate microbiological quality and end temperature (ET) of portioned food after heating in a microwave oven as used in a hospital cook/chill foodservice system. Beef loaf (15 kg), potatoes (6 kg), and green beans (5 kg) were prepared in a laboratory. After initial cooking to 60 degrees C, and storage (7 degrees C for 24 h), beef loaf (100 g) was microwave heated: 20, 50, 80 or 110 s. Potatoes were reconstituted, stored (7 degrees C for 24 h), portioned (100 g/portion), and microwave-heated: 25, 45, 65 or 84 s. Beans were thawed (7 degrees C for 24 h), portioned (100 g/portion), and microwave-heated: 20, 50, 80 or 110 s. Aerobic plate counts (APC) for foods were obtained throughout product flow. Wide ranges of Et and of APC in foods indicates that research is needed, for greater control of microwave-heating through advanced microwave engineering and food technology, to produce food with constant microbiological quality.

Spacesuit Evaporator-Absorber-Radiator (SEAR)

NASA Technical Reports Server (NTRS)

Hodgson, Ed; Izenson, Mike; Chan, Weibo; Bue, Grant C.

2012-01-01

For decades advanced spacesuit developers have pursued a regenerable, robust nonventing system for heat rejection. Toward this end, this paper investigates linking together two previously developed technologies, namely NASA s Spacesuit Water Membrane Evaporator (SWME), and Creare s Lithium Chloride Absorber Radiator (LCAR). Heat from a liquid cooled garment is transported to SWME that provides cooling through evaporation. This water vapor is then captured by solid LiCl in the LCAR with a high enthalpy of absorption, resulting in sufficient temperature lift to reject heat to space by radiation. After the sortie, the LCAR would be heated up and dried in a regenerator to drive off and recover the absorbed evaporant. A engineering development prototype was built and tested in vacuum conditions at a sink temperature of 250 K. The LCAR was able to stably reject 75 W over a 7-hour period. A conceptual design of a full-scale radiator is proposed. Excess heat rejection above 240 W would be accomplished through venting of the evaporant. Loop closure rates were predicted for various exploration environment scenarios.

Preconceptual design of a fluoride high temperature salt-cooled engineering demonstration reactor: Motivation and overview

DOE PAGES

Qualls, A. Louis; Betzler, Benjamin R.; Brown, Nicholas R.; ...

2016-12-21

Engineering demonstration reactors are nuclear reactors built to establish proof of concept for technology options that have never been built. Examples of engineering demonstration reactors include Peach Bottom 1 for high temperature gas-cooled reactors (HTGRs) and Experimental Breeder Reactor-II (EBR-II) for sodium-cooled fast reactors. Historically, engineering demonstrations have played a vital role in advancing the technology readiness level of reactor technologies. Our paper details a preconceptual design for a fluoride salt-cooled engineering demonstration reactor. The fluoride salt-cooled high-temperature reactor (FHR) demonstration reactor (DR) is a concept for a salt-cooled reactor with 100 megawatts of thermal output (MWt). It would usemore » tristructural-isotropic (TRISO) particle fuel within prismatic graphite blocks. FLiBe (2 7LiF-BeF2) is the reference primary coolant. The FHR DR is designed to be small, simple, and affordable. Development of the FHR DR is a necessary intermediate step to enable near-term commercial FHRs. The design philosophy of the FHR DR was focused on safety, near-term deployment, and flexibility. Lower risk technologies are purposely included in the initial FHR DR design to ensure that the reactor can be built, licensed, and operated as an engineering demonstration with minimal risk and cost. These technologies include TRISO particle fuel, replaceable core structures, and consistent structural material selection for core structures and the primary and intermediate loops, and tube-and-shell primary-to-intermediate heat exchangers. Important capabilities to be demonstrated by building and operating the FHR DR include fabrication and operation of high temperature reactors; heat exchanger performance (including passive decay heat removal); pump performance; and reactivity control; salt chemistry control to maximize vessel life; tritium management; core design methodologies; salt procurement, handling, maintenance and ultimate disposal. It is recognized that non-nuclear separate and integral test efforts (e.g., heated salt loops or loops using simulant fluids) are necessary to develop the technologies that will be demonstrated in the FHR DR.« less

Preconceptual design of a fluoride high temperature salt-cooled engineering demonstration reactor: Motivation and overview

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qualls, A. Louis; Betzler, Benjamin R.; Brown, Nicholas R.

Engineering demonstration reactors are nuclear reactors built to establish proof of concept for technology options that have never been built. Examples of engineering demonstration reactors include Peach Bottom 1 for high temperature gas-cooled reactors (HTGRs) and Experimental Breeder Reactor-II (EBR-II) for sodium-cooled fast reactors. Historically, engineering demonstrations have played a vital role in advancing the technology readiness level of reactor technologies. Our paper details a preconceptual design for a fluoride salt-cooled engineering demonstration reactor. The fluoride salt-cooled high-temperature reactor (FHR) demonstration reactor (DR) is a concept for a salt-cooled reactor with 100 megawatts of thermal output (MWt). It would usemore » tristructural-isotropic (TRISO) particle fuel within prismatic graphite blocks. FLiBe (2 7LiF-BeF2) is the reference primary coolant. The FHR DR is designed to be small, simple, and affordable. Development of the FHR DR is a necessary intermediate step to enable near-term commercial FHRs. The design philosophy of the FHR DR was focused on safety, near-term deployment, and flexibility. Lower risk technologies are purposely included in the initial FHR DR design to ensure that the reactor can be built, licensed, and operated as an engineering demonstration with minimal risk and cost. These technologies include TRISO particle fuel, replaceable core structures, and consistent structural material selection for core structures and the primary and intermediate loops, and tube-and-shell primary-to-intermediate heat exchangers. Important capabilities to be demonstrated by building and operating the FHR DR include fabrication and operation of high temperature reactors; heat exchanger performance (including passive decay heat removal); pump performance; and reactivity control; salt chemistry control to maximize vessel life; tritium management; core design methodologies; salt procurement, handling, maintenance and ultimate disposal. It is recognized that non-nuclear separate and integral test efforts (e.g., heated salt loops or loops using simulant fluids) are necessary to develop the technologies that will be demonstrated in the FHR DR.« less

Preliminary assessment of rover power systems for the Mars Rover Sample Return Mission

NASA Technical Reports Server (NTRS)

Bents, David J.

1989-01-01

Four isotope power system concepts were presented and compared on a common basis for application to on-board electrical prime power for an autonomous planetary rover vehicle. A representative design point corresponding to the Mars Rover Sample Return (MRSR) preliminary mission requirements (500 W) was selected for comparison purposes. All systems concepts utilize the General Purpose Heat Source (GPHS) isotope heat source developed by DOE. Two of the concepts employ thermoelectric (TE) conversion: one using the GPHS Radioisotope Thermoelectric Generator (RTG) used as a reference case, the other using an advanced RTG with improved thermoelectric materials. The other two concepts employed are dynamic isotope power systems (DIPS): one using a closed Brayton cycle (CBC) turboalternator, and the other using a free piston Stirling cycle engine/linear alternator (FPSE) with integrated heat source/heater head. Near term technology levels have been assumed for concept characterization using component technology figure-of-merit values taken from the published literature. For example, the CBC characterization draws from the historical test database accumulated from space Brayton cycle subsystems and components from the NASA B engine through the mini-Brayton rotating unit. TE system performance is estimated from Voyager/multihundred Watt (MHW)-RTG flight experience through Mod-RTG performance estimates considering recent advances in TE materials under the DOD/DOE/NASA SP-100 and NASA Committee on Scientific and Technological Information programs. The Stirling DIPS system is characterized from scaled-down Space Power Demonstrator Engine (SPDE) data using the GPHS directly incorporated into the heater head. The characterization/comparison results presented here differ from previous comparison of isotope power (made for Low Earth Orbit (LEO) applications) because of the elevated background temperature on the Martian surface compared to LEO, and the higher sensitivity of dynamic systems to elevated sink temperature. The mass advantage of dynamic systems is significantly reduced for this application due to Mars' elevated background temperature.

The transformation of heat in an engine

NASA Technical Reports Server (NTRS)

Neumann, Kurt

1929-01-01

This report presents a thermodynamic basis for rating heat engines. The production of work by a heat engine rests on the operation of supplying heat, under favorable conditions, to a working fluid and then taking it away.

Advanced Soldier Thermoelectric Power System for Power Generation from Battlefield Heat Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hendricks, Terry J.; Hogan, Tim; Case, Eldon D.

2010-09-01

The U.S. military uses large amounts of fuel during deployments and battlefield operations. This project sought to develop a lightweight, small form-factor, soldier-portable advanced thermoelectric (TE) system prototype to recover and convert waste heat from various deployed military equipment (i.e., diesel generators/engines, incinerators, vehicles, and potentially mobile kitchens), with the ultimate purpose of producing power for soldier battery charging, advanced capacitor charging, and other battlefield power applications. The technical approach employed microchannel technology, a unique “power panel” approach to heat exchange/TE system integration, and newly-characterized LAST (lead-antimony-silver-telluride) and LASTT (lead-antimony-silver-tin-telluride) TE materials segmented with bismuth telluride TE materials in designingmore » a segmented-element TE power module and system. This project researched never-before-addressed system integration challenges (thermal expansion, thermal diffusion, electrical interconnection, thermal and electrical interfaces) of designing thin “power panels” consisting of alternating layers of thin, microchannel heat exchangers (hot and cold) sandwiching thin, segmented-element TE power generators. The TE properties, structurally properties, and thermal fatigue behavior of LAST and LASTT materials were developed and characterized such that the first segmented-element TE modules using LAST / LASTT materials were fabricated and tested at hot-side temperatures = 400 °C and cold-side temperatures = 40 °C. LAST / LASTT materials were successfully segmented with bismuth telluride and electrically interconnected with diffusion barrier materials and copper strapping within the module electrical circuit. A TE system design was developed to produce 1.5-1.6 kW of electrical energy using these new TE modules from the exhaust waste heat of 60-kW Tactical Quiet Generators as demonstration vehicles.« less

Analysis of the Effects of Vitiates on Surface Heat Flux in Ground Tests of Hypersonic Vehicles

NASA Technical Reports Server (NTRS)

Cuda, Vincent; Gaffney, Richard L

2008-01-01

To achieve the high enthalpy conditions associated with hypersonic flight, many ground test facilities burn fuel in the air upstream of the test chamber. Unfortunately, the products of combustion contaminate the test gas and alter gas properties and the heat fluxes associated with aerodynamic heating. The difference in the heating rates between clean air and a vitiated test medium needs to be understood so that the thermal management system for hypersonic vehicles can be properly designed. This is particularly important for advanced hypersonic vehicle concepts powered by air-breathing propulsion systems that couple cooling requirements, fuel flow rates, and combustor performance by flowing fuel through sub-surface cooling passages to cool engine components and preheat the fuel prior to combustion. An analytical investigation was performed comparing clean air to a gas vitiated with methane/oxygen combustion products to determine if variations in gas properties contributed to changes in predicted heat flux. This investigation started with simple relationships, evolved into writing an engineering-level code, and ended with running a series of CFD cases. It was noted that it is not possible to simultaneously match all of the gas properties between clean and vitiated test gases. A study was then conducted selecting various combinations of freestream properties for a vitiated test gas that matched clean air values to determine which combination of parameters affected the computed heat transfer the least. The best combination of properties to match was the free-stream total sensible enthalpy, dynamic pressure, and either the velocity or Mach number. This combination yielded only a 2% difference in heating. Other combinations showed departures of up to 10% in the heat flux estimate.

Seals Code Development Workshop

NASA Technical Reports Server (NTRS)

Hendricks, Robert C. (Compiler); Liang, Anita D. (Compiler)

1996-01-01

Seals Workshop of 1995 industrial code (INDSEAL) release include ICYL, GCYLT, IFACE, GFACE, SPIRALG, SPIRALI, DYSEAL, and KTK. The scientific code (SCISEAL) release includes conjugate heat transfer and multidomain with rotordynamic capability. Several seals and bearings codes (e.g., HYDROFLEX, HYDROTRAN, HYDROB3D, FLOWCON1, FLOWCON2) are presented and results compared. Current computational and experimental emphasis includes multiple connected cavity flows with goals of reducing parasitic losses and gas ingestion. Labyrinth seals continue to play a significant role in sealing with face, honeycomb, and new sealing concepts under investigation for advanced engine concepts in view of strict environmental constraints. The clean sheet approach to engine design is advocated with program directions and anticipated percentage SFC reductions cited. Future activities center on engine applications with coupled seal/power/secondary flow streams.

Study of advanced radial outflow turbine for solar steam Rankine engines

NASA Technical Reports Server (NTRS)

Martin, C.; Kolenc, T.

1979-01-01

The performance characteristics of various steam Rankine engine configurations for solar electric power generation were investigated. A radial outflow steam turbine was investigated to determine: (1) a method for predicting performance from experimental data; (2) the flexibility of a single design with regard to power output and pressure ratio; and (3) the effect of varying the number of turbine stages. All turbine designs were restricted to be compatible with commercially available gearboxes and generators. A study of several operating methods and control schemes for the steam Rankine engine shows that from an efficiency and control simplicity standpoint, the best approach is to hold turbine inlet temperature constant, vary turbine inlet pressure to match load, and allow condenser temperature to float maintaining constant heat rejection load.

Improved Stirling engine performance using jet impingement

NASA Technical Reports Server (NTRS)

Johnson, D. C.; Britt, E. J.; Thieme, L. G.

1982-01-01

Of the many factors influencing the performance of a Stirling engine, that of transferring the combustion gas heat into the working fluid is crucial. By utilizing the high heat transfer rates obtainable with a jet impingement heat transfer system, it is possible to reduce the flame temperature required for engine operation. Also, the required amount of heater tube surface area may be reduced, resulting in a decrease in the engine nonswept volume and a related increase in engine efficiency. A jet impingement heat transfer system was designed by Rasor Associates, Inc., and tested in the GPU-3 Stirling engine at the NASA Lewis Research Center. For a small penalty in pumping power (less than 0.5% of engine output) the jet impingement heat transfer system provided a higher combustion-gas-side heat transfer coefficient and a smoothing of heater temperature profiles resulting in lower combustion system temperatures and a 5 to 8% increase in engine power output and efficiency.

Modeling Heat Loss through Piston and Effects of Thermal Boundary Coatings in Diesel Engine Simulations using Conjugate Heat Transfer models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kundu, Prithwish; Scarcelli, Riccardo; Som, Sibendu

Heat loss through wall boundaries play a dominant role in the overall performance and efficiency of internal combustion engines. Typical engine simulations use constant temperature wall boundary conditions. These boundary conditions cannot be estimated accurately from experiments due to the complexities involved with engine combustion. As a result they introduce a large uncertainty in engine simulations and serve as a tuning parameter. Modeling the process of heat transfer through the solid walls in an unsteady engine computational fluid dynamics (CFD) simulation can lead to the development of higher fidelity engine calculations. These models can be used to study the impactmore » of heat loss on engine efficiency and explore new design methodologies that can reduce heat losses. In this work, a single cylinder diesel engine is modeled along with the solid piston coupled to the fluid domain. Conjugate heat transfer (CHT) modeling techniques were implemented to model heat losses for a full cycle of a Navistar diesel engine. This CFD model is then validated against experimental data available from thermocouples embedded inside the piston surface. The overall predictions from the model match closely with the experimental observations. The validated model is further used to explore the benefits of thermal barrier coatings (TBC) on piston bowls. The effect of TBC coatings were modeled as a thermal resistance in the heat transfer models. Full cycle 3D engine simulations provide quantitative insights into heat loss and thus calculate the efficiency gain by the use of TBC coatings. The work establishes a validated modeling framework for CHT modeling in reciprocating engine simulations.« less

Engineering microbes for tolerance to next-generation biofuels

PubMed Central

2011-01-01

A major challenge when using microorganisms to produce bulk chemicals such as biofuels is that the production targets are often toxic to cells. Many biofuels are known to reduce cell viability through damage to the cell membrane and interference with essential physiological processes. Therefore, cells must trade off biofuel production and survival, reducing potential yields. Recently, there have been several efforts towards engineering strains for biofuel tolerance. Promising methods include engineering biofuel export systems, heat shock proteins, membrane modifications, more general stress responses, and approaches that integrate multiple tolerance strategies. In addition, in situ recovery methods and media supplements can help to ease the burden of end-product toxicity and may be used in combination with genetic approaches. Recent advances in systems and synthetic biology provide a framework for tolerance engineering. This review highlights recent targeted approaches towards improving microbial tolerance to next-generation biofuels with a particular emphasis on strategies that will improve production. PMID:21936941

Creep Behavior of Hafnia and Ytterbium Silicate Environmental Barrier Coating Systems on SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Fox, Dennis S.; Ghosn, Louis J.; Harder, Bryan

2011-01-01

Environmental barrier coatings will play a crucial role in future advanced gas turbine engines because of their ability to significantly extend the temperature capability and stability of SiC/SiC ceramic matrix composite (CMC) engine components, thus improving the engine performance. In order to develop high performance, robust coating systems for engine components, appropriate test approaches simulating operating temperature gradient and stress environments for evaluating the critical coating properties must be established. In this paper, thermal gradient mechanical testing approaches for evaluating creep and fatigue behavior of environmental barrier coated SiC/SiC CMC systems will be described. The creep and fatigue behavior of Hafnia and ytterbium silicate environmental barrier coatings on SiC/SiC CMC systems will be reported in simulated environmental exposure conditions. The coating failure mechanisms will also be discussed under the heat flux and stress conditions.

The Development of Erosion and Impact Resistant Turbine Airfoil Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2007-01-01

Thermal barrier coatings are used in gas turbine engines to protect engine hot-section components in the harsh combustion environments and extend component lifetimes. For thermal barrier coatings designed for turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability. Advanced erosion resistant thermal barrier coatings are being developed, with a current emphasis on the toughness improvements using a combined rare earth- and transition metal-oxide doping approach. The performance of the doped thermal barrier coatings has been evaluated in burner rig and laser heat-flux rig simulated engine erosion and thermal gradient environments. The results have shown that the coating composition optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic durability. The erosion and impact damage mechanisms of the thermal barrier coatings will also be discussed.

High Thermal Conductivity NARloy-Z-Diamond Composite Liner for Advanced Rocket Engines

NASA Technical Reports Server (NTRS)

Bhat, Biliyar; Greene, Sandra

2015-01-01

NARloy-Z (Cu-3Ag-0.5Zr) alloy is state-of-the-art combustion chamber liner material used in liquid propulsion engines such as the RS-68 and RS-25. The performance of future liquid propulsion systems can be improved significantly by increasing the heat transfer through the combustion chamber liner. Prior work1 done at NASA Marshall Space Flight Center (MSFC) has shown that the thermal conductivity of NARloy-Z alloy can be improved significantly by embedding high thermal conductivity diamond particles in the alloy matrix to form NARloy-Z-diamond composite (fig. 1). NARloy-Z-diamond composite containing 40vol% diamond showed 69% higher thermal conductivity than NARloy-Z. It is 24% lighter than NARloy-Z and hence the density normalized thermal conductivity is 120% better. These attributes will improve the performance and life of the advanced rocket engines significantly. The research work consists of (a) developing design properties (thermal and mechanical) of NARloy-Z-D composite, (b) fabrication of net shape subscale combustion chamber liner, and (c) hot-fire testing of the liner to test performance. Initially, NARloy-Z-D composite slabs were made using the Field Assisted Sintering Technology (FAST) for the purpose of determining design properties. In the next step, a cylindrical shape was fabricated to demonstrate feasibility (fig. 3). The liner consists of six cylinders which are sintered separately and then stacked and diffusion bonded to make the liner (fig. 4). The liner will be heat treated, finish-machined, and assembled into a combustion chamber and hot-fire tested in the MSFC test facility (TF 115) to determine perform.

Exergetic simulation of a combined infrared-convective drying process

NASA Astrophysics Data System (ADS)

Aghbashlo, Mortaza

2016-04-01

Optimal design and performance of a combined infrared-convective drying system with respect to the energy issue is extremely put through the application of advanced engineering analyses. This article proposes a theoretical approach for exergy analysis of the combined infrared-convective drying process using a simple heat and mass transfer model. The applicability of the developed model to actual drying processes was proved using an illustrative example for a typical food.

Heat Pipes Reduce Engine-Exhaust Emissions

NASA Technical Reports Server (NTRS)

Schultz, D. F.

1986-01-01

Increased fuel vaporization raises engine efficiency. Heat-pipe technology increased efficiency of heat transfer beyond that obtained by metallic conduction. Resulted in both improved engine operation and reduction in fuel consumption. Raw material conservation through reduced dependence on strategic materials also benefit from this type of heat-pipe technology. Applications result in improved engine performance and cleaner environment.

Novikov Engine with Fluctuating Heat Bath Temperature

NASA Astrophysics Data System (ADS)

Schwalbe, Karsten; Hoffmann, Karl Heinz

2018-04-01

The Novikov engine is a model for heat engines that takes the irreversible character of heat fluxes into account. Using this model, the maximum power output as well as the corresponding efficiency of the heat engine can be deduced, leading to the well-known Curzon-Ahlborn efficiency. The classical model assumes constant heat bath temperatures, which is not a reasonable assumption in the case of fluctuating heat sources. Therefore, in this article the influence of stochastic fluctuations of the hot heat bath's temperature on the optimal performance measures is investigated. For this purpose, a Novikov engine with fluctuating heat bath temperature is considered. Doing so, a generalization of the Curzon-Ahlborn efficiency is found. The results can help to quantify how the distribution of fluctuating quantities affects the performance measures of power plants.

Advanced Stirling Convertor (ASC) Technology Maturation

NASA Technical Reports Server (NTRS)

Wong, Wayne A.; Wilson, Scott; Collins, Josh; Wilson, Kyle

2015-01-01

The Advanced Stirling Convertor (ASC) development effort was initiated by NASA Glenn Research Center (GRC) with contractor Sunpower Inc. to develop high efficiency thermal-to-electric power conversion technology for NASA Radioisotope Power Systems. Early successful performance demonstrations led to the expansion of the project as well as adoption of the technology by the Department of Energy (DOE) and system integration contractor Lockheed Martin Space Systems Company as part of the Advanced Stirling Radioisotope Generator (ASRG) flight project. The ASRG integrates a pair of ASCs to convert the heat from a pair of General Purpose Heat Source (GPHS) modules into electrical power. The expanded NASA ASC effort included development of several generations of ASC prototypes or Engineering Units to help prepare the ASC technology and Sunpower for flight implementation. Sunpower later had two parallel contracts allowing the last of the NASA Engineering Units called ASC-E3 to serve as pathfinders for the ASC-F flight convertors being built for DOE. The ASC-E3 convertors utilized the ASC-F flight specifications and were built using the ASC-F design and process documentation. Shortly after the first ASC-F Pair achieved initial operation, due to budget constraints, the DOE ASRG flight development contract was terminated. NASA continues to invest in the development of Stirling RPS technology including continued production of the ASC-E3 convertors, seven of which have been delivered with one additional unit in production. Starting in FY2015, Stirling Convertor Technology Maturation has been reorganized as an element of the RPS Stirling Cycle Technology Development (SCTD) Project and long-term plans for continued Stirling technology advancement are in reformulation. This paper provides a status on the ASC project, an overview of advancements made in the design and production of the ASC at Sunpower, and a summary of acceptance tests, reliability tests, and tactical tests at NASA GRC that demonstrate the capabilities of the ASC.

Advanced Stirling Convertor (ASC) Technology Maturation

NASA Technical Reports Server (NTRS)

Wong, Wayne A.; Wilson, Scott; Collins, Josh; Wilson, Kyle

2016-01-01

The Advanced Stirling Convertor (ASC) development effort was initiated by NASA Glenn Research Center with contractor Sunpower, Inc., to develop high-efficiency thermal-to-electric power conversion technology for NASA Radioisotope Power Systems (RPSs). Early successful performance demonstrations led to the expansion of the project as well as adoption of the technology by the Department of Energy (DOE) and system integration contractor Lockheed Martin Space Systems Company as part of the Advanced Stirling Radioisotope Generator (ASRG) flight project. The ASRG integrates a pair of ASCs to convert the heat from a pair of General Purpose Heat Source (GPHS) modules into electrical power. The expanded NASA ASC effort included development of several generations of ASC prototypes or engineering units to help prepare the ASC technology and Sunpower for flight implementation. Sunpower later had two parallel contracts allowing the last of the NASA engineering units called ASC-E3 to serve as pathfinders for the ASC-F flight convertors being built for DOE. The ASC-E3 convertors utilized the ASC-F flight specifications and were built using the ASC-F design and process documentation. Shortly after the first ASC-F pair achieved initial operation, due to budget constraints, the DOE ASRG flight development contract was terminated. NASA continues to invest in the development of Stirling RPS technology including continued production of the ASC-E3 convertors, seven of which have been delivered with one additional unit in production. Starting in fiscal year 2015, Stirling Convertor Technology Maturation has been reorganized as an element of the RPS Stirling Cycle Technology Development (SCTD) Project and long-term plans for continued Stirling technology advancement are in reformulation. This paper provides a status on the ASC project, an overview of advancements made in the design and production of the ASC at Sunpower, and a summary of acceptance tests, reliability tests, and tactical tests at NASA Glenn that demonstrate the capabilities of the ASC.

Mechanical equivalent of quantum heat engines.

PubMed

Arnaud, Jacques; Chusseau, Laurent; Philippe, Fabrice

2008-06-01

Quantum heat engines employ as working agents multilevel systems instead of classical gases. We show that under some conditions quantum heat engines are equivalent to a series of reservoirs at different altitudes containing balls of various weights. A cycle consists of picking up at random a ball from one reservoir and carrying it to the next, thereby performing or absorbing some work. In particular, quantum heat engines, employing two-level atoms as working agents, are modeled by reservoirs containing balls of weight 0 or 1. The mechanical model helps us prove that the maximum efficiency of quantum heat engines is the Carnot efficiency. Heat pumps and negative temperatures are considered.

Full-scale simulation and reduced-order modeling of a thermoacoustic engine

NASA Astrophysics Data System (ADS)

Scalo, Carlo; Lin, Jeff; Lele, Sanjiva; Hesselink, Lambertus

2013-11-01

We have carried out the first three-dimensional numerical simulation of a thermoacoustic Stirling heat-engine. The goal is to lay the groundwork for full-scale Navier-Stokes simulations to advance the state-of-the-art low-order modeling and design of such devices. The model adopted is a long resonator with a heat-exchanger/regenerator (HX/REG) unit on one end - the only component not directly resolved. A temperature difference across the HX/REG unit of 200 K is sufficient to initiate the thermoacoustic instability. The latter is a Lagrangian process that only intensifies acoustic waves traveling in the direction of the imposed temperature gradient. An acoustic network of traveling waves is thus obtained and compared against low-order prediction tools such as DeltaEC. Non-linear effects such as system-wide streaming flow patterns are rapidly established. These are responsible for the mean advection of hot fluid away from the HX/REG (i.e. thermal leakage). This unwanted effect is contained by the introduction of a second ambient heat-exchanger allowing for the establishment of a dynamical thermal equilibrium in the system. A limit cycle is obtained at +178 dB.

Verification of combined thermal-hydraulic and heat conduction analysis code FLOWNET/TRUMP

NASA Astrophysics Data System (ADS)

Maruyama, Soh; Fujimoto, Nozomu; Kiso, Yoshihiro; Murakami, Tomoyuki; Sudo, Yukio

1988-09-01

This report presents the verification results of the combined thermal-hydraulic and heat conduction analysis code, FLOWNET/TRUMP which has been utilized for the core thermal hydraulic design, especially for the analysis of flow distribution among fuel block coolant channels, the determination of thermal boundary conditions for fuel block stress analysis and the estimation of fuel temperature in the case of fuel block coolant channel blockage accident in the design of the High Temperature Engineering Test Reactor(HTTR), which the Japan Atomic Energy Research Institute has been planning to construct in order to establish basic technologies for future advanced very high temperature gas-cooled reactors and to be served as an irradiation test reactor for promotion of innovative high temperature new frontier technologies. The verification of the code was done through the comparison between the analytical results and experimental results of the Helium Engineering Demonstration Loop Multi-channel Test Section(HENDEL T(sub 1-M)) with simulated fuel rods and fuel blocks.

PROCEEDINGS OF THE 1999 OIL HEAT TECHNOLOGY CONFERENCE AND WORKSHOP.

DOE Office of Scientific and Technical Information (OSTI.GOV)

MCDONALD,R.J.

1999-04-01

The 1999 Oil Heat Technology Conference and Workshop, April 15-16 at Brookhaven National Laboratory (BNL) is sponsored by the U. S. Department of Energy, Office of Building Technology, State and Community Programs (DOEBTS). The meeting is also co-sponsored by the: Petroleum Marketers Association of America, New England Fuel Institute, Oilheat Manufacturers Association, National Association of Oil Heat Service Managers, New York State Energy Research and Development Authority, Empire State Petroleum Association, New York Oil Heating Association, Oil Heat Institute of Long Island, and the Pennsylvania Petroleum Association. BNL is proud to acknowledge all of our 1999 co-sponsors, without their helpmore » and support the conference would have been canceled due to budget restrictions. It is quite gratifying to see an industry come together to help support an activity like the technology conference, for the benefit of the industry as a whole. The 1999 Oil Heat Technology Conference and Workshop, will be the thirteenth since 1984, is a very valuable technology transfer activity supported by the ongoing Combustion Equipment Technology (Oilheat R and D) program at BNL. The foremost reason for the conference is to provide a platform for the exchange of information and perspectives among international researchers, engineers, manufacturers, service technicians, and marketers of oil-fired space-conditioning equipment. They will provide a conduit by which information and ideas can be exchanged to examine present technologies, as well as helping to develop the future course for oil heating advancement. These conferences also serve as a stage for unifying government representatives, researchers, fuel oil marketers, and other members of the oil-heat industry in addressing technology advancements in this important energy use sector.« less

Advanced high temperature materials for the energy efficient automotive Stirling engine

NASA Technical Reports Server (NTRS)

Titran, R. H.; Stephens, J. R.

1984-01-01

The Stirling Engine is under investigated jointly by the Department of Energy and NASA Lewis as an alternative to the internal combustion engine for automotive applications. The Stirling Engine is an external combustion engine that offers the advantage of high fuel economy, low emissions, low noise, and low vibrations compared to current internal combustion automotive engines. The most critical component from a materials viewpoint is the heater head consisting of the cylinders, heating tubes, and regenerator housing. Materials requirements for the heater head include compatibility with hydrogen, resistance to hydrogen permeation, high temperature oxidation/corrosion resistance and high temperature creep-rupture and fatigue properties. A continuing supporting materials research and technology program has identified the wrought alloys CG-27 and 12RN72 and the cast alloys XF-818 and NASAUT 4G-A1 as candidate replacements for the cobalt containing alloys used in current prototype engines. Based on the materials research program in support of the automotive Stirling engine it is concluded that manufacture of the engine is feasible from low cost iron-base alloys rather than the cobalt alloys rather than the cobalt alloys used in prototype engines. This paper will present results of research that led to this conclusion.

The second law of thermodynamics and quantum heat engines: Is the law strictly enforced?

NASA Astrophysics Data System (ADS)

Keefe, Peter D.

2010-01-01

A quantum heat engine is a construct having a working medium which is cyclically processed through a pair of control variables of state involving a Bose-Einstein condensation (BEC) in which a heat input is converted into a work output. Of interest is a first species of quantum heat engine in which the working medium is macroscopic in the sense the size scale is sufficiently large that the BEC is not volumetrically coherent. In this first species of quantum heat engine, near Carnot efficiencies may be possible. Of particular interest is a second species of quantum heat engine in which the working medium is mesoscopic in the sense that the size scale is sufficiently small that the BEC is volumetrically coherent. In this second species of quantum heat engine, the resulting in-process non-equilibrium condition affects the finally arrived at control variables of state such that Carnot efficiencies and beyond may be possible. A Type I superconductor is used to model the first and second species of quantum heat engine.

60NiTi Alloy for Tribological and Biomedical Surface Engineering Applications

NASA Astrophysics Data System (ADS)

Ingole, Sudeep

2013-06-01

60NiTi is an alloy with 60 wt% of nickel (Ni) and 40 wt% of titanium (Ti). This alloy was developed in the 1950s at the Naval Ordnance Laboratory (NOL) along with 55NiTi (55 wt% of Ni and 45 wt% of Ti). Both of these alloys exhibit the shape memory effect to different extents. The unique properties of 60NiTi, which are suitable for surface engineering (tribological) applications, are enumerated here. With appropriate heat treatment, this alloy can achieve high hardness (between Rc 55 and Rc 63). It has very good corrosion resistance and is resilient. Machinable before its final heat treatment, this alloy can be ground to fine surface finish and to tight dimensions. At one time, due to the popularity and wider applications of 55NiTi, the study of 60NiTi suffered. Recently, 60NiTi alloy gained some technological advantages due to advanced materials synthesis processes and progress in surface engineering. A feasibility study of 60NiTi bearings for space application has shown promise for its further development and suitability for other tribological applications. This report focuses on an overview of the properties and potential tribological and biomedical applications of 60NiTi.

Overview of free-piston Stirling engine technology for space power application

NASA Technical Reports Server (NTRS)

Slaby, Jack G.

1987-01-01

An overview is presented of free-piston Stirling engine activities, directed toward space power applications. One of the major elements of the program is the development of advanced power conversion. Under this program the status of the 25 kWe opposed-piston Space Power Demonstrator Engine (SPDE) is presented. Initial differences between predicted and experimental power outputs and power output influenced by variations in regenerators are discussed. Technology work was conducted on heat-exchanger concepts to minimize the number of joints as well as to enhance the heat transfer in the heater. Design parameters and conceptual design features are also presented for a 25 kWe, single-cylinder free-piston Stirling space power converter. Projections are made for future space power requirements over the next few decades along with a recommendation to consider the use of dynamic power conversion systems, either solar or nuclear. A cursory comparison is presented showing the mass benefits of a Stirling system over a Brayton system for the same peak temperature and output power. A description of a study to investigate the feasibility of scaling a single-cylinder free-piston Stirling space power module to the 150 kWe power range is presented.

Energy Systems Integration Facility (ESIF): Golden, CO - Energy Integration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheppy, Michael; VanGeet, Otto; Pless, Shanti

2015-03-01

At NREL's Energy Systems Integration Facility (ESIF) in Golden, Colo., scientists and engineers work to overcome challenges related to how the nation generates, delivers and uses energy by modernizing the interplay between energy sources, infrastructure, and data. Test facilities include a megawatt-scale ac electric grid, photovoltaic simulators and a load bank. Additionally, a high performance computing data center (HPCDC) is dedicated to advancing renewable energy and energy efficient technologies. A key design strategy is to use waste heat from the HPCDC to heat parts of the building. The ESIF boasts an annual EUI of 168.3 kBtu/ft2. This article describes themore » building's procurement, design and first year of performance.« less

Adsorption Refrigeration System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Kai; Vineyard, Edward Allan

Adsorption refrigeration is an environmentally friendly cooling technology which could be driven by recovered waste heat or low-grade heat such as solar energy. In comparison with absorption system, an adsorption system has no problems such as corrosion at high temperature and salt crystallization. In comparison with vapor compression refrigeration system, it has the advantages of simple control, no moving parts and less noise. This paper introduces the basic theory of adsorption cycle as well as the advanced adsorption cycles such as heat and mass recovery cycle, thermal wave cycle and convection thermal wave cycle. The types, characteristics, advantages and drawbacksmore » of different adsorbents used in adsorption refrigeration systems are also summarized. This article will increase the awareness of this emerging cooling technology among the HVAC engineers and help them select appropriate adsorption systems in energy-efficient building design.« less

Cryogenic hydrogen-induced air-liquefaction technologies

NASA Technical Reports Server (NTRS)

Escher, William J. D.

1990-01-01

Extensive use of a special advanced airbreathing propulsion archives data base, as well as direct contacts with individuals who were active in the field in previous years, a technical assessment of cryogenic hydrogen induced air liquefaction, as a prospective onboard aerospace vehicle process, was performed and documented in 1986. The resulting assessment report is summarized. Technical findings relating the status of air liquefaction technology are presented both as a singular technical area, and also as that of a cluster of collateral technical areas including: Compact lightweight cryogenic heat exchangers; Heat exchanger atmospheric constituents fouling alleviation; Para/ortho hydrogen shift conversion catalysts; Hydrogen turbine expanders, cryogenic air compressors and liquid air pumps; Hydrogen recycling using slush hydrogen as heat sinks; Liquid hydrogen/liquid air rocket type combustion devices; Air Collection and Enrichment System (ACES); and Technically related engine concepts.

An investigation of enhanced capability thermal barrier coating systems for diesel engine components

NASA Technical Reports Server (NTRS)

Holtzman, R. L.; Layne, J. L.; Schechter, B.

1984-01-01

Material systems and processes for the development of effective and durable thermal barriers for heavy duty diesel engines were investigated. Seven coating systems were evaluated for thermal conductivity, erosion resistance, corrosion/oxidation resistance, and thermal shock resistance. An advanced coating system based on plasma sprayed particle yttria stabilized zirconia (PS/HYSZ) was judged superior in these tests. The measured thermal conductivity of the selected coating was 0.893 W/m C at 371 C. The PS/HYSZ coating system was applied to the piston crown, fire deck and valves of a single cylinder low heat rejection diesel engine. The coated engine components were tested for 24 hr at power levels from 0.83 MPa to 1.17 MPa brake mean effective pressure. The component coatings survived the engine tests with a minimum of distress. The measured fire deck temperatures decreased 86 C (155 F) on the intake side and 42 C (75 F) on the exhaust side with the coating applied.

Periodic unsteady effects on turbulent boundary layer transport and heat transfer: An experimental investigation in a cylinder-wall junction flow

NASA Astrophysics Data System (ADS)

Xie, Qi

Heat transfer in a turbulent boundary layer downstream of junction with a cylinder has many engineering applications including controlling heat transfer to the endwall in gas turbine passages and cooling of protruding electronic chips. The main objective of this research is to study the fundamental process of heat transport and wall heat transfer in a turbulent three-dimensional flow superimposed with local large-scale periodic unsteadiness generated by vortex shedding from the cylinder. Direct measurements of the Reynolds heat fluxes (/line{utheta},\\ /line{vtheta}\\ and\\ /line{wtheta}) and time-resolved wall heat transfer rate will provide insight into unsteady flow behavior and data for advanced turbulence models for numerical simulation of complex engineering flows. Experiments were conducted in an open-circuit, low-speed wind tunnel. Reynolds stresses and heat fluxes were obtained from turbulent heat-flux probes which consisted of two hot wires, arranged in an X-wire configuration, and a cold wire located in front of the X-wire. Thin-film surface heat flux sensors were designed for measuring time-resolved wall heat flux. A reference probe and conditional-sampling technique connected the flow field dynamics to wall heat transfer. An event detecting and ensemble-averaging method was developed to separate effects of unsteadiness from those of background turbulence. Results indicate that unsteadiness affects both heat transport and wall heat transfer. The flow behind the cylinder can be characterized by three regions: (1) Wake region, where unsteadiness is observed to have modest effect; (2) Unsteady region, where the strongest unsteadiness effect is found; (3) Outer region, where the flow approaches the two-dimensional boundary-layer behavior. Vortex shedding from both sides of the cylinder contributes to mixing enhancement in the wake region. Unsteadiness contributes up to 51% of vertical and 59% of spanwise turbulent heat fluxes in the unsteady region. The instantaneous wall Stanton number increased up to 100% compared with an undisturbed flow. Large-scale fluctuations of wall Stanton number were due to the periodic thinning and thickening of the thermal layer caused by periodic vertical velocity fluctuations. This suggests that the outerlayer motion affects near-wall flow behavior and wall heat transfer.

A Self-Circulating Heat Exchanger for Use in Stirling and Thermoacoustic-Stirling Engines

NASA Astrophysics Data System (ADS)

Backhaus, Scott; Reid, Robert S.

2005-02-01

A major technical hurdle to the implementation of large Stirling engines or thermoacoustic engines is the reliability, performance, and manufacturability of the hot heat exchanger that brings high-temperature heat into the engine. Unlike power conversion devices that utilize steady flow, the oscillatory nature of the flow in Stirling and thermoacoustic engines restricts the length of a traditional hot heat exchanger to a peak-to-peak gas displacement, which is usually around 0.2 meters or less. To overcome this restriction, a new hot heat exchanger has been devised that uses a fluid diode in a looped pipe, which is resonantly driven by the oscillating gas pressure in the engine itself, to circulate the engine's working fluid around the loop. Instead of thousands of short, intricately interwoven passages that must be individually sealed, this new design consists of a few pipes that are typically 10 meters long. This revolutionary approach eliminates thousands of hermetic joints, pumps the engine's working fluid to and from a remote heat source without using moving parts, and does so without compromising on heat transfer surface area. Test data on a prototype loop integrated with a 1-kW thermoacoustic engine will be presented.

Holographic heat engine within the framework of massive gravity

NASA Astrophysics Data System (ADS)

Mo, Jie-Xiong; Li, Gu-Qiang

2018-05-01

Heat engine models are constructed within the framework of massive gravity in this paper. For the four-dimensional charged black holes in massive gravity, it is shown that the existence of graviton mass improves the heat engine efficiency significantly. The situation is more complicated for the five-dimensional neutral black holes since the constant which corresponds to the third massive potential also contributes to the efficiency. It is also shown that the existence of graviton mass can improve the heat engine efficiency. Moreover, we probe how the massive gravity influences the behavior of the heat engine efficiency approaching the Carnot efficiency.

Advanced single crystal for SSME turbopumps

NASA Technical Reports Server (NTRS)

Fritzemeier, L. G.

1989-01-01

The objective of this program was to evaluate the influence of high thermal gradient casting, hot isostatic pressing (HIP) and alternate heat treatments on the microstructure and mechanical properties of a single crystal nickel base superalloy. The alloy chosen for the study was PWA 1480, a well characterized, commercial alloy which had previously been chosen as a candidate for the Space Shuttle Main Engine high pressure turbopump turbine blades. Microstructural characterization evaluated the influence of casting thermal gradient on dendrite arm spacing, casting porosity distribution and alloy homogeneity. Hot isostatic pressing was evaluated as a means of eliminating porosity as a preferred fatigue crack initiation site. The alternate heat treatment was chosen to improve hydrogen environment embrittlement resistance and for potential fatigue life improvement. Mechanical property evaluation was aimed primarily at determining improvements in low cycle and high cycle fatigue life due to the advanced processing methods. Statistically significant numbers of tests were conducted to quantitatively demonstrate life differences. High thermal gradient casting improves as-cast homogeneity, which facilitates solution heat treatment of PWA 1480 and provides a decrease in internal pore size, leading to increases in low cycle and high cycle fatigue lives.

Integrated Heat Exchange For Recuperation In Gas Turbine Engines

DTIC Science & Technology

2016-12-01

exchange system within the engine using existing blade surfaces to extract and insert heat. Due to the highly turbulent and transient flow, heat...transfer coefficients in turbomachinery are extremely high, making this possible. Heat transfer between the turbine and compressor blade surfaces could be...exchange system within the engine using existing blade surfaces to extract and insert heat. Due to the highly turbulent and transient flow, heat transfer

Small Stirling dynamic isotope power system for multihundred-watt robotic missions

NASA Technical Reports Server (NTRS)

Bents, David J.

1991-01-01

Free Piston Stirling Engine (FPSE) and linear alternator (LA) technology is combined with radioisotope heat sources to produce a compact dynamic isotope power system (DIPS) suitable for multihundred watt space application which appears competitive with advance radioisotope thermoelectric generators (RTGs). The small Stirling DIPS is scalable to multihundred watt power levels or lower. The FPSE/LA is a high efficiency convertor in sizes ranging from tens of kilowatts down to only a few watts. At multihundred watt unit size, the FPSE can be directly integrated with the General Purpose Heat Source (GPHS) via radiative coupling; the resulting dynamic isotope power system has a size and weight that compares favorably with the advanced modular (Mod) RTG, but requires less than a third the amount of isotope fuel. Thus the FPSE extends the high efficiency advantage of dynamic systems into a power range never previously considered competitive for DIPS. This results in lower fuel cost and reduced radiological hazard per delivered electrical watt.

Small Stirling dynamic isotope power system for multihundred-watt robotic missions

NASA Technical Reports Server (NTRS)

Bents, David J.

1991-01-01

Free piston Stirling Engine (FPSE) and linear alternator (LA) technology is combined with radioisotope heat sources to produce a compact dynamic isotope power system (DIPS) suitable for multihundred watt space application which appears competitive with advanced radioisotope thermoelectric generators (RTGs). The small Stirling DIPS is scalable to multihundred watt power levels or lower. The FPSE/LA is a high efficiency convertor in sizes ranging from tens of kilowatts down to only a few watts. At multihundred watt unit size, the FPSE can be directly integrated with the General Purpose Heat Source (GPHS) via radiative coupling; the resulting dynamic isotope power system has a size and weight that compares favorably with the advanced modular (Mod) RTG, but requires less than a third the amount of isotope fuel. Thus the FPSE extends the high efficiency advantage of dynamic systems into a power range never previously considered competitive for DIPS. This results in lower fuel cost and reduced radiological hazard per delivered electrical watt.

The Development of HfO2-Rare Earth Based Oxide Materials and Barrier Coatings for Thermal Protection Systems

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan James

2014-01-01

Advanced hafnia-rare earth oxides, rare earth aluminates and silicates have been developed for thermal environmental barrier systems for aerospace propulsion engine and thermal protection applications. The high temperature stability, low thermal conductivity, excellent oxidation resistance and mechanical properties of these oxide material systems make them attractive and potentially viable for thermal protection systems. This paper will focus on the development of the high performance and high temperature capable ZrO2HfO2-rare earth based alloy and compound oxide materials, processed as protective coating systems using state-or-the-art processing techniques. The emphasis has been in particular placed on assessing their temperature capability, stability and suitability for advanced space vehicle entry thermal protection systems. Fundamental thermophysical and thermomechanical properties of the material systems have been investigated at high temperatures. Laser high-heat-flux testing has also been developed to validate the material systems, and demonstrating durability under space entry high heat flux conditions.

Advanced Oxide Material Systems for 1650 C Thermal/Environmental Barrier Coating Applications

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Fox, Dennis S.; Bansal, Narottam P.; Miller, Robert A.

2004-01-01

Advanced thermal and environmental barrier coatings (TEBCs) are being developed for low-emission SiC/SiC ceramic matrix composite (CMC) combustor and vane applications to extend the CMC liner and vane temperature capability to 1650 C (3000 F) in oxidizing and water-vapor-containing combustion environments. The advanced 1650 C TEBC system is required to have a better high-temperature stability, lower thermal conductivity, and more resistance to sintering and thermal stress than current coating systems under engine high-heat-flux and severe thermal cycling conditions. In this report, the thermal conductivity and water vapor stability of selected candidate hafnia-, pyrochlore- and magnetoplumbite-based TEBC materials are evaluated. The effects of dopants on the materials properties are also discussed. The test results have been used to downselect the TEBC materials and help demonstrate the feasibility of advanced 1650 C coatings with long-term thermal cycling durability.

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 chamber liner. Properties of optimized NARloy-Z-D composite material will also be presented.

Tribological characteristics of silicon carbide whisker-reinforced alumina at elevated temperatures

NASA Technical Reports Server (NTRS)

Dellacorte, Christopher

1991-01-01

The enhanced fracture toughness of whisker reinforced ceramics makes them attractive candidates for sliding components of advanced hear engines. Examples include piston rings and valve stems for Stirling engines and other low heat rejection devices. However, the tribological behavior of whisker reinforced ceramics is largely unknown. This is especially true for the applications described where use temperatures can vary from below ambient to well over 1000 C. An experimental research program to identify the dominant wear mechanism(s) for a silicon carbide whisker reinforced alumina composite, SiCw-Al2O3 is described. In addition, a wear mechanism model is developed to explain and corroborate the experimental results and to provide insight for material improvement.

Gradient complex protective coatings for single-crystal turbine blades of high-heat gas turbine engines

NASA Astrophysics Data System (ADS)

Kuznetsov, V. P.; Lesnikov, V. P.; Muboyadzhyan, S. A.; Repina, O. V.

2007-05-01

Complex diffusion-condensation protective coatings characterized by gradient distribution of alloying elements over the thickness due to formation of a diffusion barrier layer on the surface of blades followed by deposition of condensation alloyed layers based on the Ni-Co-Cr-Al-Y system and an external layer based on a NiAl alloyed β-phase and a ZrO2: Y2O3 ceramics are presented. A complex gradient coating possessing unique protective properties at t = 1100-1200°C for single-crystal blades from alloy ZhS36VI for advanced gas turbine engines with gas temperature of 1550°C at the inlet to the turbine is described.

Heat pipe cooling for scramjet engines

NASA Technical Reports Server (NTRS)

Silverstein, Calvin C.

1986-01-01

Liquid metal heat pipe cooling systems have been investigated for the combustor liner and engine inlet leading edges of scramjet engines for a missile application. The combustor liner is cooled by a lithium-TZM molybdenum annular heat pipe, which incorporates a separate lithium reservoir. Heat is initially absorbed by the sensible thermal capacity of the heat pipe and liner, and subsequently by the vaporization and discharge of lithium to the atmosphere. The combustor liner temperature is maintained at 3400 F or less during steady-state cruise. The engine inlet leading edge is fabricated as a sodium-superalloy heat pipe. Cooling is accomplished by radiation of heat from the aft surface of the leading edge to the atmosphere. The leading edge temperature is limited to 1700 F or less. It is concluded that heat pipe cooling is a viable method for limiting scramjet combustor liner and engine inlet temperatures to levels at which structural integrity is greatly enhanced.

Heat Exchanger Design and Testing for a 6-Inch Rotating Detonation Engine

DTIC Science & Technology

2013-03-01

Engine Research Facility HHV Higher heating value LHV Lower heating value PDE Pulsed detonation engine RDE Rotating detonation engine RTD...the combustion community are pulse detonation engines ( PDEs ) and rotating detonation engines (RDEs). 1.1 Differences between Pulsed and Rotating ...steadier than that of a PDE (2, 3). (2) (3) Figure 1. Unrolled rotating detonation wave from high-speed video (4) Another difference that

Advanced Environmental Barrier Coating and SA Tyrannohex SiC Composites Integration for Improved Thermomechanical and Environmental Durability

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Halbig, Michael; Singh, Mrityunjay

2018-01-01

The development of 2700 degF capable environmental barrier coating (EBC) systems, particularly, the Rare Earth "Hafnium" Silicon bond coat systems, have significantly improved the temperature capability and environmental stability of SiC/SiC Ceramic Matrix Composite Systems. We have specifically developed the advanced 2700 degF EBC systems, integrating the EBC to the high temperature SA Tyrannohex SiC fiber composites, for comprehensive performance and durability evaluations for potential turbine engine airfoil component applications. The fundamental mechanical properties, environmental stability and thermal gradient cyclic durability performance of the EBC - SA Tyrannohex composites were investigated. The paper will particularly emphasize the high pressure combustion rig recession, cyclic thermal stress resistance and thermomechanical low cycle fatigue testing of uncoated and environmental barrier coated Tyrannohex SiC SA composites in these simulated turbine engine combustion water vapor, thermal gradients, and mechanical loading conditions. We have also investigated high heat flux and flexural fatigue degradation mechanisms, determined the upper limits of operating temperature conditions for the coated SA composite material systems in thermomechanical fatigue conditions. Recent progress has also been made by using the self-healing rare earth-silicon based EBCs, thus enhancing the SA composite hexagonal fiber columns bonding for improved thermomechanical and environmental durability in turbine engine operation environments. More advanced EBC- composite systems based on the new EBC-Fiber Interphases will also be discussed.

Advanced Stirling Radioisotope Generator Engineering Unit 2 Anomaly Investigation

NASA Technical Reports Server (NTRS)

Lewandowski, Edward J.; Dobbs, Michael W.; Oriti, Salvatore M.

2018-01-01

The Advanced Stirling Radioisotope Generator (ASRG) Engineering Unit 2 (EU2) is the highest fidelity electrically heated Stirling radioisotope generator built to date. NASA Glenn Research Center completed the assembly of the ASRG EU2 in September 2014 using hardware from the now cancelled ASRG flight development project. The ASRG EU2 integrated the first pair of Sunpower's Advanced Stirling Convertors (ASC-E3 #1 and #2) in an aluminum generator housing with Lockheed Martin's (LM's) Engineering Development Unit (EDU) 4 controller. After just 179 hr of EU2 generator operation, the first power fluctuation occurred on ASC-E3 #1. The first power fluctuation occurred 175 hr later on ASC-E3 #2. Over time, the power fluctuations became more frequent on both convertors and larger in magnitude. Eventually the EU2 was shut down in January 2015. An anomaly investigation was chartered to determine root cause of the power fluctuations and other anomalous observations. A team with members from Glenn, Sunpower, and LM conducted a thorough investigation of the EU2 anomalies. Findings from the EU2 disassembly identified proximate causes of the anomalous observations. Discussion of the team's assessment of the primary possible failure theories, root cause, and conclusions is provided. Recommendations are made for future Stirling generator development to address the findings from the anomaly investigation. Additional findings from the investigation are also discussed.

Efficiencies and coefficients of performance of heat engines, refrigerators, and heat pumps with friction: a universal limiting behavior.

PubMed

Bizarro, João P S; Rodrigues, Paulo

2012-11-01

For work-producing heat engines, or work-consuming refrigerators and heat pumps, the percentage decrease caused by friction in their efficiencies, or coefficients of performance (COP's), is approximately given by the ratio W(fric)/W between the work spent against friction forces and the work performed by, or delivered to, the working fluid. This universal scaling, which applies in the limit of small friction (W(fric)/W

Diesel engine emissions and combustion predictions using advanced mixing models applicable to fuel sprays

NASA Astrophysics Data System (ADS)

Abani, Neerav; Reitz, Rolf D.

2010-09-01

An advanced mixing model was applied to study engine emissions and combustion with different injection strategies ranging from multiple injections, early injection and grouped-hole nozzle injection in light and heavy duty diesel engines. The model was implemented in the KIVA-CHEMKIN engine combustion code and simulations were conducted at different mesh resolutions. The model was compared with the standard KIVA spray model that uses the Lagrangian-Drop and Eulerian-Fluid (LDEF) approach, and a Gas Jet spray model that improves predictions of liquid sprays. A Vapor Particle Method (VPM) is introduced that accounts for sub-grid scale mixing of fuel vapor and more accurately and predicts the mixing of fuel-vapor over a range of mesh resolutions. The fuel vapor is transported as particles until a certain distance from nozzle is reached where the local jet half-width is adequately resolved by the local mesh scale. Within this distance the vapor particle is transported while releasing fuel vapor locally, as determined by a weighting factor. The VPM model more accurately predicts fuel-vapor penetrations for early cycle injections and flame lift-off lengths for late cycle injections. Engine combustion computations show that as compared to the standard KIVA and Gas Jet spray models, the VPM spray model improves predictions of in-cylinder pressure, heat released rate and engine emissions of NOx, CO and soot with coarse mesh resolutions. The VPM spray model is thus a good tool for efficiently investigating diesel engine combustion with practical mesh resolutions, thereby saving computer time.

Development and Performance Evaluations of HfO2-Si and Rare Earth-Si Based Environmental Barrier Bond Coat Systems for SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2014-01-01

Ceramic environmental barrier coatings (EBC) and SiCSiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft propulsion systems because of their ability to significantly increase engine operating temperatures, improve component durability, reduce engine weight and cooling requirements. Advanced EBC systems for SiCSiC CMC turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant material development challenges for the high temperature CMC components is to develop prime-reliant, high strength and high temperature capable environmental barrier coating bond coat systems, since the current silicon bond coat cannot meet the advanced EBC-CMC temperature and stability requirements. In this paper, advanced NASA HfO2-Si based EBC bond coat systems for SiCSiC CMC combustor and turbine airfoil applications are investigated. The coating design approach and stability requirements are specifically emphasized, with the development and implementation focusing on Plasma Sprayed (PS) and Electron Beam-Physic Vapor Deposited (EB-PVD) coating systems and the composition optimizations. High temperature properties of the HfO2-Si based bond coat systems, including the strength, fracture toughness, creep resistance, and oxidation resistance were evaluated in the temperature range of 1200 to 1500 C. Thermal gradient heat flux low cycle fatigue and furnace cyclic oxidation durability tests were also performed at temperatures up to 1500 C. The coating strength improvements, degradation and failure modes of the environmental barrier coating bond coat systems on SiCSiC CMCs tested in simulated stress-environment interactions are briefly discussed and supported by modeling. The performance enhancements of the HfO2-Si bond coat systems with rare earth element dopants and rare earth-silicon based bond coats are also highlighted. The advanced bond coat systems, when integrated with advanced EBC top coats, showed promise to achieve 1500 C temperature capability, helping enable next generation turbine engines with significantly improved engine component temperature capability and long-term durability.

Heat transfer to throat tubes in a square-chambered rocket engine at the NASA Lewis Research Center

NASA Technical Reports Server (NTRS)

Nesbitt, James A.; Brindley, William J.

1989-01-01

A gaseous H2/O2 rocket engine was constructed at the NASA-Lewis to provide a high heat flux source representative of the heat flux to the blades in the high pressure fuel turbopump (HPFTP) during startup of the space shuttle main engines. The high heat flux source was required to evaluate the durability of thermal barrier coatings being investigated for use on these blades. The heat transfer, and specifically, the heat flux to tubes located at the throat of the test rocket engine was evaluated and compared to the heat flux to the blades in the HPFTP during engine startup. Gas temperatures, pressures and heat transfer coefficients in the test rocket engine were measured. Near surface metal temperatures below thin thermal barrier coatings were also measured at various angular orientations around the throat tube to indicate the angular dependence of the heat transfer coefficients. A finite difference model for a throat tube was developed and a thermal analysis was performed using the measured gas temperatures and the derived heat transfer coefficients to predict metal temperatures in the tube. Near surface metal temperatures of an uncoated throat tube were measured at the stagnation point and showed good agreement with temperatures predicted by the thermal model. The maximum heat flux to the throat tube was calculated and compared to that predicted for the leading edge of an HPFTP blade. It is shown that the heat flux to an uncooled throat tube is slightly greater than the heat flux to an HPFTP blade during engine startup.

Development of a Lunar Consumables Storage and Distribution Depot

NASA Technical Reports Server (NTRS)

Mueller, Robert P.; Notardonato, William

2004-01-01

NASA is in the preliminary planning stages for a future lunar base as a response to President George W. Bush's recent announcement of a new sustained exploration program beyond low earth orbit. Kennedy Space Center engineers are supporting this program by utilizing experience in Spaceport system design and operations to help develop a Lunar Consumables Depot. This depot will store propellants, life support fluids, and other consumables either transported from Earth or manufactured from In Situ resources. The depot will distribute these consumables in an energy efficient manner to end users including spacecraft, habitation modules, and rovers. This paper addresses some of the changes to lunar base architecture design as a result of advances in knowledge of lunar resources over the past 35 years, as well as technology advances in the area of In Situ Resource Utilization and consumable storage and distribution. A general system level description of the depot will be presented, including overall design philosophy and high level requirements. Finally, specific subsystem technologies that have been or will be developed by KSC will be addressed. Examples of these technologies are automated umbilicals, cryogenic refrigerators, novel storage vessels, advanced heat switches and heat exchangers, and self healing gaskets and wires.

MEMS CLOSED CHAMBER HEAT ENGINE AND ELECTRIC GENERATOR

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A. (Inventor)

2005-01-01

A heat engine, preferably combined with an electric generator, and advantageously implemented using micro-electromechanical system (MEMS) technologies as an array of one or more individual heat engine/generators. The heat engine is based on a closed chamber containing a motive medium, preferably a gas; means for alternately enabling and disabling transfer of thermal energy from a heat source to the motive medium; and at least one movable side of the chamber that moves in response to thermally-induced expansion and contraction of the motive medium, thereby converting thermal energy to oscillating movement. The electrical generator is combined with the heat engine to utilize movement of the movable side to convert mechanical work to electrical energy, preferably using electrostatic interaction in a generator capacitor. Preferably at least one heat transfer side of the chamber is placed alternately into and out of contact with the heat source by a motion capacitor, thereby alternately enabling and disabling conductive transfer of heat to the motive medium.

Novel biofuel formulations for enhanced vehicle performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Dennis; Narayan, Ramani; Berglund, Kris

2013-08-30

This interdisciplinary research program at Michigan State University, in collaboration with Ford Motor Company, has explored the application of tailored or designed biofuels for enhanced vehicle performance and reduced emissions. The project has included a broad range of experimental research, from chemical and biological formation of advanced biofuel components to multicylinder engine testing of blended biofuels to determine engine performance parameters. In addition, the project included computation modeling of biofuel physical and combustion properties, and simulation of advanced combustion modes in model engines and in single cylinder engines. Formation of advanced biofuel components included the fermentation of five-carbon and six-carbonmore » sugars to n-butanol and to butyric acid, two four-carbon building blocks. Chemical transformations include the esterification of the butyric acid produced to make butyrate esters, and the esterification of succinic acid with n-butanol to make dibutyl succinate (DBS) as attractive biofuel components. The conversion of standard biodiesel, made from canola or soy oil, from the methyl ester to the butyl ester (which has better fuel properties), and the ozonolysis of biodiesel and the raw oil to produce nonanoate fuel components were also examined in detail. Physical and combustion properties of these advanced biofuel components were determined during the project. Physical properties such as vapor pressure, heat of evaporation, density, and surface tension, and low temperature properties of cloud point and cold filter plugging point were examined for pure components and for blends of components with biodiesel and standard petroleum diesel. Combustion properties, particularly emission delay that is the key parameter in compression ignition engines, was measured in the MSU Rapid Compression Machine (RCM), an apparatus that was designed and constructed during the project simulating the compression stroke of an internal combustion engine under highly instrumented conditions. Simulation of and experimentation on combustion in single and multicylinder engines was carried out in detail throughout the project. The combustion behavior of biofuel blends neat and in petroleum were characterized in the MSU optical engine, in part to validate results obtained in the RCM and to provide data for comparison with simulations. Simulation of in- cylinder, low-temperature combustion included development of an extensive fuel injection model that included fuel spray breakup, evaporation, and ignition, along with prediction of cylinder temperature, pressure, and work produced. Single cylinder and multicylinder engine tests under advanced low-temperature combustion conditions conducted at Ford Motor Company validated experimental and simulation results obtained in the MSU engine and in MSU simulations. Single cylinder engine tests of an advanced biofuel containing biodiesel and dibutyl succinate, carried out under low-temperature combustion conditions, showed similar power generation and gas-phase emissions (CO, HC, NOx), but a reduction in particulates of as much as 60% relative to neat biodiesel and 95% relative to petroleum diesel at the same operating conditions. This remarkable finding suggests that biofuels may be able to play a role in eliminating the need for particulate removal systems in diesel vehicles. The multicylinder engine tests at Ford, carried out using butyl nonanoate as an advanced biofuel, also gave promising results, showing a strong decline in particulate emissions and simultaneously a modest decrease in NOx emissions relative to standard petroleum diesel at the same conditions. In summary, this project has shown that advanced biofuels and their blends are capable of maintaining performance while reducing emissions, particularly particulates (soot), in 3 compression ignition engines. The interdisciplinary nature of biofuel production and testing has identified fuel properties that are capable of producing such performance, thus providing direction for the implementation of renewable fuels for U.S. transportation. The testing and simulation studies have deepened our understanding of combustion 1) by advancing the rigor with which simulations can be carried out and 2) by illustrating that differences in biofuel and petroleum fuel properties can be used to predict differences in combustion behavior in engines. The future viability of biofuels for compression ignition (diesel) engines is now subject to economic (cost) uncertainty more so than to technical barriers, as the advanced biofuel blends developed here can improve cold-weather fuel properties, provide similar engine performance, and reduce emissions.« less

Metallized Gelled Propellants: Oxygen/RP-1/Aluminum Rocket Engine Calorimeter Heat Transfer Measurements and Analysis

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

1997-01-01

A set of analyses was conducted to determine the heat transfer characteristics of metallized gelled liquid propellants in a rocket engine. The analyses used the data from experiments conducted with a small 30- to 40-lbf thrust engine composed of a modular injector, igniter, chamber and nozzle. The fuels used were traditional liquid RP-1 and gelled RP-1 with 0-wt %, 5-wt%, and 55-wt% loadings of aluminum with silicon dioxide gellant, and gaseous oxygen as the oxidizer. Heat transfer was computed based on measurements using calorimeter rocket chamber and nozzle hardware with a total of 31 cooling channels. A gelled fuel coating formed in the 0-, 5- and 55-wt% engines, and the coating was composed of unburned gelled fuel and partially combusted RP-1. The coating caused a large decrease in calorimeter engine heat flux in the last half of the chamber for the 0- and 5-wt% RP-1/Al. This heat flux reduction effect was analyzed by comparing engine runs and the changes in the heat flux during a run as well as from run to run. Heat transfer and time-dependent heat flux analyses and interpretations are provided. The 5- and 55-wt% RP-1/Al fueled engines had the highest chamber heat fluxes, with the 5-wt% fuel having the highest throat flux. This result is counter to the predicted result, where the 55 wt% fuel has the highest combustion and throat temperature, and therefore implies that it would deliver the highest throat heat flux. The 5-wt% RP-1/Al produced the most influence on the engine heat transfer and the heat flux reduction was caused by the formation of a gelled propellant layer in the chamber and nozzle.

Design of a Facility to Test the Advanced Stirling Radioisotope Generator Engineering Unit

NASA Technical Reports Server (NTRS)

Lewandowski, Edward J.; Schreiber, Jeffrey G.; Oriti, Salvatore M.; Meer, David W.; Brace, Michael H.; Dugala, Gina

2009-01-01

The Advanced Stirling Radioisotope Generator (ASRG) is being considered to power deep space missions. An engineering unit, the ASRG-EU, was designed and fabricated by Lockheed Martin under contract to the Department of Energy. This unit is currently on an extended operation test at NASA Glenn Research Center to generate performance data and validate the life and reliability predictions for the generator and the Stirling convertors. A special test facility was designed and built for testing the ASRG-EU. Details of the test facility design are discussed. The facility can operate the convertors under AC bus control or with the ASRG-EU controller. It can regulate input thermal power in either a fixed temperature or fixed power mode. An enclosure circulates cooled air around the ASRG-EU to remove heat rejected from the ASRG-EU by convection. A custom monitoring and data acquisition system supports the test. Various safety features, which allow 2417 unattended operation, are discussed.

Advances in cryogenic engineering. Volume 27 - Proceedings of the Cryogenic Engineering Conference, San Diego, CA, August 11-14, 1981

NASA Astrophysics Data System (ADS)

Fast, R. W.

Applications of superconductivity are considered, taking into account MHD and fusion, generators, transformers, transmission lines, magnets for physics, cryogenic techniques, electrtronics, and aspects of magnet stability. Advances related to heat transfer in He I are discussed along with subjects related to theat transfer in He II, refrigeration of superconducting systems, refrigeration and liquefaction, dilution and magnetic refrigerators, refrigerators for space applications, mass transfer and flow phenomena, and the properties of fluids. Developments related to cryogenic applications are also explored, giving attention to bulk storage and transfer of cryogenic fluids, liquefied natural gas operations, space science and technology, and cryopumping. Topics related to cryogenic instrumentation and controls include the production and use of high grade silicon diode temperature sensors, the choice of strain gages for use in a large superconducting alternator, microprocessor control of cryogenic pressure, and instrumentation, data acquisition and reduction for a large spaceborne helium dewar. For individual items see A83-43221 to A83-43250

Gas-heat-pump development

NASA Astrophysics Data System (ADS)

Creswick, F. A.

Incentives for the development of gas heat pumps are discussed. Technical progress made on several promising technologies was reviewed. The status of development of gas-engine-driven heat pumps, the absorption cycle for the near- and long-term gas heat pump systems, the Stirling engine, the small Rankine-cycle engines, and gas-turbine-driven heat pump systems were briefly reviewed. Progress in the US, Japan, and Europe is noted.

Impact of Paint Color on Rest Period Climate Control Loads in Long-Haul Trucks: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lustbader, J.; Kreutzer, C.; Jeffers, M.

Cab climate conditioning is one of the primary reasons for operating the main engine in a long-haul truck during driver rest periods. In the United States, sleeper cab trucks use approximately 667 million gallons of fuel annually for rest period idling. The U.S. Department of Energy's National Renewable Energy Laboratory's (NREL) CoolCab Project works closely with industry to design efficient thermal management systems for long-haul trucks that minimize engine idling and fuel use while maintaining occupant comfort. Heat transfer to the vehicle interior from opaque exterior surfaces is one of the major heat pathways that contribute to air conditioning loadsmore » during long-haul truck daytime rest period idling. To quantify the impact of paint color and the opportunity for advanced paints, NREL collaborated with Volvo Group North America, PPG Industries, and Dometic Environmental Corporation. Initial screening simulations using CoolCalc, NREL's rapid HVAC load estimation tool, showed promising air-conditioning load reductions due to paint color selection. Tests conducted at NREL's Vehicle Testing and Integration Facility using long-haul truck cab sections, 'test bucks,' showed a 31.1% of maximum possible reduction in rise over ambient temperature and a 20.8% reduction in daily electric air conditioning energy use by switching from black to white paint. Additionally, changing from blue to an advanced color-matched solar reflective blue paint resulted in a 7.3% reduction in daily electric air conditioning energy use for weather conditions tested in Colorado. National-level modeling results using weather data from major U.S. cities indicated that the increase in heating loads due to lighter paint colors is much smaller than the reduction in cooling loads.« less

Seminar on the Structure of Aeronautical R&D Held in Lisbon, Portugal on 31 May-1 Jun 1990, Patras, Greece on 4-5 June 1990 and Ankara, Turkey on 7-8 June 1990 (La Structure de la Recherche et Developpement en Aeronautique)

DTIC Science & Technology

1990-05-01

comprehension du processus de la R&D a6ronautiquc, mais elles sont loin d𔄀tre exhaustives . Les opinions et les exp6riences pr6sent6es dmanent de lAm6rique...into the exhaust nozzle, possibly with some low level of F Liquid ..... j afterburning during the acceleration phase. Advanced engine technology...hypersonic vehicles show stagnation temperatures much lower, Obviously, advanced cooling methods such as heat pipes will be required. However. at lower

Heat exchanger design for hot air ericsson-brayton piston engine

NASA Astrophysics Data System (ADS)

Ďurčanský, P.; Lenhard, R.; Jandačka, J.

2014-03-01

One of the solutions without negative consequences for the increasing energy consumption in the world may be use of alternative energy sources in micro-cogeneration. Currently it is looking for different solutions and there are many possible ways. Cogeneration is known for long time and is widely used. But the installations are often large and the installed output is more suitable for cities or industry companies. When we will speak about decentralization, the small machines have to be used. The article deals with the principle of hot-air engines, their use in combined heat and electricity production from biomass and with heat exchangers as primary energy transforming element. In the article is hot air engine presented as a heat engine that allows the conversion of heat into mechanical energy while heat supply can be external. In the contribution are compared cycles of hot-air engine. Then are compared suitable heat exchangers for use with hot air Ericsson-Brayton engine. In the final part is proposal of heat exchanger for use in closed Ericsson-Brayton cycle.

Rate of Heat Release in Diesel Engines

DOT National Transportation Integrated Search

1977-10-01

In this report, the concept of heat release in diesel engines is compared with reaction rates in petrol engines as a means of describing combustion. The intimate relationships between heat release, cylinder pressure development and cylinder pressure ...

Analysis of heat recovery of diesel engine using intermediate working fluid

NASA Astrophysics Data System (ADS)

Jin, Lei; Zhang, Jiang; Tan, Gangfeng; Liu, Huaming

2017-07-01

The organic Rankine cycle (ORC) is an effective way to recovery the engine exhaust heat. The thermal stability of the evaporation system is significant for the stable operation of the ORC system. In this paper, the performance of the designed evaporation system which combines with the intermediate fluid for recovering the exhaust waste heat from a diesel engine is evaluated. The thermal characteristics of the target diesel engine exhaust gas are evaluated based on the experimental data firstly. Then, the mathematical model of the evaporation system is built based on the geometrical parameters and the specific working conditions of ORC. Finally, the heat transfer characteristics of the evaporation system are estimated corresponding to three typical operating conditions of the diesel engine. The result shows that the exhaust temperature at the evaporator outlet increases slightly with the engine speed and load. In the evaporator, the heat transfer coefficient of the Rankine working fluid is slightly larger than the intermediate fluid. However, the heat transfer coefficient of the intermediate fluid in the heat exchanger is larger than the exhaust side. The heat transfer areas of the evaporator in both the two-phase zone and the preheated zone change slightly along with the engine working condition while the heat transfer areas of the overheated zone has changed obviously. The maximum heat transfer rate occurs in the preheating zone while the minimum value occurs in the overheating zone. In addition, the Rankine working fluid temperature at the evaporator outlet is not sensitively affected by the torque and speed of the engine and the organic fluid flow is relatively stable. It is concluded that the intermediate fluid could effectively reduce the physical changes of Rankine working fluid in the evaporator outlet due to changes in engine operating conditions.

Advanced Methods for Aircraft Engine Thrust and Noise Benefits: Nozzle-Inlet Flow Analysis

NASA Technical Reports Server (NTRS)

Morgan, Morris H., III; Gilinsky, Mikhail M.

2004-01-01

In this project on the first stage (2000-Ol), we continued to develop the previous joint research between the Fluid Mechanics and Acoustics Laboratory (FM&AL) at Hampton University (HU) and the Jet Noise Team (JNT) at the NASA Langley Research Center (NASA LaRC). At the second stage (2001-03), FM&AL team concentrated its efforts on solving of problems of interest to Glenn Research Center (NASA GRC), especially in the field of propulsion system enhancement. The NASA GRC R&D Directorate and LaRC Hyper-X Program specialists in a hypersonic technology jointly with the FM&AL staff conducted research on a wide region of problems in the propulsion field as well as in experimental testing and theoretical and numerical simulation analyses for advanced aircraft and rocket engines. The last year the Hampton University School of Engineering & Technology was awarded the NASA grant, for creation of the Aeropropulsion Center, and the FM&AL is a key team of the project fulfillment responsible for research in Aeropropulsion and Acoustics (Pillar I). This work is supported by joint research between the NASA GRC/ FM&AL and the Institute of Mechanics at Moscow State University (IMMSU) in Russia under a CRDF grant. The main areas of current scientific interest of the FM&AL include an investigation of the proposed and patented advanced methods for aircraft engine thrust and noise benefits. This is the main subject of our other projects, of which one is presented. The last year we concentrated our efforts to analyze three main problems: (a) new effective methods fuel injection into the flow stream in air-breathing engines; (b) new re-circulation method for mixing, heat transfer and combustion enhancement in propulsion systems and domestic industry application; (c) covexity flow The research is focused on a wide regime of problems in the propulsion field as well as in experimental testing and theoretical and numerical simulation analyses for advanced aircraft and rocket engines (see, for example, Figures 4). The FM&AL Team uses analytical methods, numerical simulations and experimental tests at the Hampton University campus, NASA and IM/MSU.

Furnace Cyclic Behavior of Plasma-Sprayed Zirconia-Yttria and Multi-Component Rare Earth Oxide Doped Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Nesbitt, James A.; McCue, Terry R.; Barrett, Charles A.; Miller, Robert A.

2002-01-01

Ceramic thermal barrier coatings will play an increasingly important role in advanced gas turbine engines because of their ability to enable further increases in engine temperatures. However, the coating performance and durability become a major concern under the increasingly harsh thermal cycling conditions. Advanced zirconia- and hafnia-based cluster oxide thermal barrier coatings with lower thermal conductivity and improved thermal stability are being developed using a high-heat-flux laser-rig based test approach. Although the new composition coatings were not yet optimized for cyclic durability, an initial durability screening of numerous candidate coating materials was carried out using conventional furnace cyclic tests. In this paper, furnace thermal cyclic behavior of the advanced plasma-sprayed zirconia-yttria-based thermal barrier coatings that were co-doped with multi-component rare earth oxides was investigated at 1163 C using 45 min hot cycles. The ceramic coating failure mechanisms were studied by using scanning electron microscopy combined with X-ray diffraction phase analysis after the furnace tests. The coating cyclic lifetime will be discussed in relation to coating phase structures, total dopant concentrations, and other properties.

Advanced Environmental Barrier Coating Development for SiC/SiC Ceramic Matrix Composites: NASA's Perspectives

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2016-01-01

This presentation reviews NASA environmental barrier coating (EBC) system development programs and the coating materials evolutions for protecting the SiC/SiC Ceramic Matrix Composites in order to meet the next generation engine performance requirements. The presentation focuses on several generations of NASA EBC systems, EBC-CMC component system technologies for SiC/SiC ceramic matrix composite combustors and turbine airfoils, highlighting the temperature capability and durability improvements in simulated engine high heat flux, high pressure, high velocity, and with mechanical creep and fatigue loading conditions. The current EBC development emphasis is placed on advanced NASA 2700F candidate environmental barrier coating systems for SiC/SiC CMCs, their performance benefits and design limitations in long-term operation and combustion environments. Major technical barriers in developing environmental barrier coating systems, the coating integrations with next generation CMCs having the improved environmental stability, erosion-impact resistance, and long-term fatigue-environment system durability performance are described. The research and development opportunities for advanced turbine airfoil environmental barrier coating systems by utilizing improved compositions, state-of-the-art processing methods, and simulated environment testing and durability modeling are discussed.

The NSF-RCN Urban Heat Island Network

NASA Astrophysics Data System (ADS)

Twine, T. E.; Snyder, P. K.; Hamilton, P.; Shepherd, M.; Stone, B., Jr.

2014-12-01

In much of the world cities are warming at twice the rate of outlying rural areas. The frequency of urban heat waves is projected to increase with climate change through the 21stcentury. Addressing the economic, environmental, and human costs of urban heat islands requires a better understanding of their behavior from many disciplinary perspectives. The goal of this four-year Urban Heat Island Network is to (1) bring together scientists studying the causes and impacts of urban warming, (2) advance multidisciplinary understanding of urban heat islands, (3) examine how they can be ameliorated through engineering and design practices, and (4) share these new insights with a wide array of stakeholders responsible for managing urban warming to reduce their health, economic, and environmental impacts. The Urban Heat Island Network involves atmospheric scientists, engineers, architects, landscape designers, urban planners, public health experts, and education and outreach experts, who will share knowledge, evaluate research directions, and communicate knowledge and research recommendations to the larger research community as well as stakeholders engaged in developing strategies to adapt to and mitigate urban warming. The first Urban Climate Institute was held in Saint Paul, Minnesota in July 2013 and focused on the characteristics of urban heat islands. Scientists engaged with local practitioners to improve communication pathways surrounding issues of understanding, adapting to, and mitigating urban warming. The second Urban Climate Institute was held in Atlanta, Georgia in July 2014 and focused on urban warming and public health. Scientists discussed the state of the science on urban modeling, heat adaptation, air pollution, and infectious disease. Practitioners informed participants on emergency response methods and protocols related to heat and other extreme weather events. Evaluation experts at the Science Museum of Minnesota have extensively evaluated both Institutes to improve future Institutes and to inform other research coordination networks. Two more Institutes are planned for 2015 and 2016 focusing on urban warming and the built environment, and education and outreach.

The Base Engine for Solar Stirling Power

NASA Technical Reports Server (NTRS)

Meijer, R. J.; Godett, T. M.

1984-01-01

A new concept in Stirling engine technology is embodied in the base engine now being developed at Stirling Thermal Motors, Inc. This is a versatile energy conversion unit suitable for many different applications and heat sources. The base engine, rated 40 kW at 2800 RPM, is a four-cylinder, double-acting variable displacement Stirling engine with pressurized crankcase and rotating shaft seal. Remote-heating technology is incorporated with a stacked-heat-exchanger configuration and a liquid metal heat pipe connected to a distinctly separate combustor or other heat source. High efficiency over a wide range of operating conditions, long life, low manufacturing cost and low material cost are specifically emphasized. The base engine, its design philosophy and approach, its projected performance, and some of its more attractive applications are described.

Small-scale heat detection using catalytic microengines irradiated by laser

NASA Astrophysics Data System (ADS)

Liu, Zhaoqian; Li, Jinxing; Wang, Jiao; Huang, Gaoshan; Liu, Ran; Mei, Yongfeng

2013-01-01

We demonstrate a novel approach to modulating the motion speed of catalytic microtubular engines via laser irradiation/heating with regard to small-scale heat detection. Laser irradiation on the engines leads to a thermal heating effect and thus enhances the engine speed. During a laser on/off period, the motion behaviour of a microengine can be repeatable and reversible, demonstrating a regulation of motion speeds triggered by laser illumination. Also, the engine velocity exhibits a linear dependence on laser power in various fuel concentrations, which implies an application potential as local heat sensors. Our work may hold great promise in applications such as lab on a chip, micro/nano factories, and environmental detection.We demonstrate a novel approach to modulating the motion speed of catalytic microtubular engines via laser irradiation/heating with regard to small-scale heat detection. Laser irradiation on the engines leads to a thermal heating effect and thus enhances the engine speed. During a laser on/off period, the motion behaviour of a microengine can be repeatable and reversible, demonstrating a regulation of motion speeds triggered by laser illumination. Also, the engine velocity exhibits a linear dependence on laser power in various fuel concentrations, which implies an application potential as local heat sensors. Our work may hold great promise in applications such as lab on a chip, micro/nano factories, and environmental detection. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr32494f

Optimized Heat Pipe Backup Cooling System Tested with a Stirling Convertor

NASA Technical Reports Server (NTRS)

Tarau, Calin; Schwendeman, Carl L.; Schifer, Nicholas A.; Anderson, William G.

2016-01-01

Advanced Stirling Radioisotope Generator (ASRG) is an attractive energy system for select space missions, and with the addition of a VCHP, it becomes even more versatile. The ASRG is powered through thermal energy from decaying radioisotopes acting as General Purpose Heat Sources (GPHS). A Stirling engine converts the thermal energy to electrical energy and cools the GPHS [2]. The Stirling convertor must operate continuously to maintain acceptable temperatures of the GPHS and protect their cladding. The addition of alkali metal VCHP allows the Stirling to cycle on and off during a mission and can be used as a backup cooling system. The benefits of being able to turn the Stirling off are: allowing for a restart of the Stirling and reducing vibrations for sensitive measurements. The VCHP addition should also increase the efficiency of the Stirling by providing a uniform temperature distribution at the heat transfer interface into the heater head.

Colloidal heat engines: a review.

PubMed

Martínez, Ignacio A; Roldán, Édgar; Dinis, Luis; Rica, Raúl A

2016-12-21

Stochastic heat engines can be built using colloidal particles trapped using optical tweezers. Here we review recent experimental realizations of microscopic heat engines. We first revisit the theoretical framework of stochastic thermodynamics that allows to describe the fluctuating behavior of the energy fluxes that occur at mesoscopic scales, and then discuss recent implementations of the colloidal equivalents to the macroscopic Stirling, Carnot and steam engines. These small-scale motors exhibit unique features in terms of power and efficiency fluctuations that have no equivalent in the macroscopic world. We also consider a second pathway for work extraction from colloidal engines operating between active bacterial reservoirs at different temperatures, which could significantly boost the performance of passive heat engines at the mesoscale. Finally, we provide some guidance on how the work extracted from colloidal heat engines can be used to generate net particle or energy currents, proposing a new generation of experiments with colloidal systems.

The Scaling of Performance and Losses in Miniature Internal Combustion Engines

DTIC Science & Technology

2010-01-01

reliable measurements of engine performance and losses in these small engines. Methodologies are also developed for measuring volumetric, heat transfer...making reliable measurements of engine performance and losses in these small engines. Methodologies are also developed for measuring volumetric, heat ...the most important challenge as it accounts for 60-70% of total energy losses. Combustion losses are followed in order of importance by heat transfer

A program for advancing the technology of space concentrators

NASA Technical Reports Server (NTRS)

Naujokas, Gerald J.; Savino, Joseph M.

1989-01-01

In 1985, the NASA Lewis Research Center formed a project, the Advanced Solar Dynamics Power Systems Project, for the purpose of advancing the technology of Solar Dynamic Power Systems for space applications beyond 2000. Since then, technology development activities have been initiated for the major components and subsystems such as the concentrator, heat receiver and engine, and radiator. Described here is a program for developing long lived (10 years or more), lighter weight, and more reflective space solar concentrators than is presently possible. The program is progressing along two parallel paths: one is concentrator concept development and the other is the resolution of those critical technology issues that will lead to durable, highly specular, and lightweight reflector elements. Outlined are the specific objectives, long-term goals, approach, planned accomplishments for the future, and the present status of the various program elements.

A program for advancing the technology of space concentrators

NASA Technical Reports Server (NTRS)

Naujokas, Gerald J.; Savino, Joseph M.

1989-01-01

In 1985, the NASA Lewis Research Center formed a project, the Advanced Solar Dynamics Power Systems Project, for the purpose of advancing the technology of Solar Dynamic Power Systems for space applications beyond 2000. Since then, technology development activities have been initiated for the major components and subsystems such as the concentrator, heat receiver and engine, and radiator. Described here is a program for developing long lived (10 years or more), lighter weight, and more reflective space solar concentrators than is presently possible. The program is progressing along two parallel paths: one is concentrator concept development and the other is the resolution of those critical technology issues that will lead to durable, highly specular, and lightweight reflector elements. Outlined are the specific objectives, long term goals, approach, planned accomplishments for the future, and the present status of the various program elements.

Development of Advanced In-Cylinder Components and Tribological Systems for Low Heat Rejection Diesel Engines. Phases 2, 3, and 4

DTIC Science & Technology

1999-06-01

Glenn Research Center Under Interagency Agreement DE -AI05-960R22547 for U.S. Department of Energy Conservation and Renewable Energy Office of...diametrically mounted proximity sensors in the cylinder liner wall. An illustration of the measurement hardware is shown in Figure 3.1.10. ~ t I...I I / Proximity Figure 3.1.10: Piston rotation measurement hardware. ~ I Cylinder Liner Piston Groove The proximity sensors were used to

Development of Advanced Stirling Radioisotope Generator for Space Exploration

NASA Technical Reports Server (NTRS)

Chan, Jack; Wood, J. Gary; Schreiber, Jeffrey G.

2007-01-01

Under the joint sponsorship of the Department of Energy and NASA, a radioisotope power system utilizing Stirling power conversion technology is being developed for potential future space missions. The higher conversion efficiency of the Stirling cycle compared with that of Radioisotope Thermoelectric Generators (RTGs) used in previous missions (Viking, Pioneer, Voyager, Galileo, Ulysses, Cassini, and New Horizons) offers the advantage of a four-fold reduction in PuO2 fuel, thereby saving cost and reducing radiation exposure to support personnel. With the advancement of state-of-the-art Stirling technology development under the NASA Research Announcement (NRA) project, the Stirling Radioisotope Generator program has evolved to incorporate the advanced Stirling convertor (ASC), provided by Sunpower, into an engineering unit. Due to the reduced envelope and lighter mass of the ASC compared to the previous Stirling convertor, the specific power of the flight generator is projected to increase from 3.5 to 7 We/kg, along with a 25 percent reduction in generator length. Modifications are being made to the ASC design to incorporate features for thermal, mechanical, and electrical integration with the engineering unit. These include the heat collector for hot end interface, cold-side flange for waste heat removal and structural attachment, and piston position sensor for ASC control and power factor correction. A single-fault tolerant, active power factor correction controller is used to synchronize the Stirling convertors, condition the electrical power from AC to DC, and to control the ASCs to maintain operation within temperature and piston stroke limits. Development activities at Sunpower and NASA Glenn Research Center (GRC) are also being conducted on the ASC to demonstrate the capability for long life, high reliability, and flight qualification needed for use in future missions.

Copper Alloy For High-Temperature Uses

NASA Technical Reports Server (NTRS)

Dreshfield, Robert L.; Ellis, David L.; Michal, Gary

1994-01-01

Alloy of Cu/8Cr/4Nb (numbers indicate parts by atom percent) improved over older high-temperature copper-based alloys in that it offers enhanced high temperature strength, resistance to creep, and ductility while retaining most of thermal conductivity of pure copper; in addition, alloy does not become embrittled upon exposure to hydrogen at temperatures as high as 705 degrees C. Designed for use in presence of high heat fluxes and active cooling; for example, in heat exchangers in advanced aircraft and spacecraft engines, and other high-temperature applications in which there is need for such material. High conductivity and hardness of alloy exploited in welding electrodes and in high-voltage and high-current switches and other applications in which wear poses design problem.

High-energy synchrotron x-ray techniques for studying irradiated materials

DOE PAGES

Park, Jun-Sang; Zhang, Xuan; Sharma, Hemant; ...

2015-03-20

High performance materials that can withstand radiation, heat, multiaxial stresses, and corrosive environment are necessary for the deployment of advanced nuclear energy systems. Nondestructive in situ experimental techniques utilizing high energy x-rays from synchrotron sources can be an attractive set of tools for engineers and scientists to investigate the structure–processing–property relationship systematically at smaller length scales and help build better material models. In this paper, two unique and interconnected experimental techniques, namely, simultaneous small-angle/wide-angle x-ray scattering (SAXS/WAXS) and far-field high-energy diffraction microscopy (FF-HEDM) are presented. Finally, the changes in material state as Fe-based alloys are heated to high temperatures ormore » subject to irradiation are examined using these techniques.« less

Start up system for hydrogen generator used with an internal combustion engine

NASA Technical Reports Server (NTRS)

Houseman, J.; Cerini, D. J. (Inventor)

1977-01-01

A hydrogen generator provides hydrogen rich product gases which are mixed with the fuel being supplied to an internal combustion engine for the purpose of enabling a very lean mixture of that fuel to be used, whereby nitrous oxides emitted by the engine are minimized. The hydrogen generator contains a catalyst which must be heated to a pre-determined temperature before it can react properly. To simplify the process of heating up the catalyst at start-up time, either some of the energy produced by the engine such as engine exhaust gas, or electrical energy produced by the engine, or the engine exhaust gas may be used to heat up air which is then used to heat the catalyst.

The second law, Maxwell's demon, and work derivable from quantum heat engines.

PubMed

Kieu, Tien D

2004-10-01

With a class of quantum heat engines which consists of two-energy-eigenstate systems undergoing, respectively, quantum adiabatic processes and energy exchanges with heat baths at different stages of a cycle, we are able to clarify some important aspects of the second law of thermodynamics. The quantum heat engines also offer a practical way, as an alternative to Szilard's engine, to physically realize Maxwell's demon. While respecting the second law on the average, they are also capable of extracting more work from the heat baths than is otherwise possible in thermal equilibrium.

Assessment of total efficiency in adiabatic engines

NASA Astrophysics Data System (ADS)

Mitianiec, W.

2016-09-01

The paper presents influence of ceramic coating in all surfaces of the combustion chamber of SI four-stroke engine on working parameters mainly on heat balance and total efficiency. Three cases of engine were considered: standard without ceramic coating, fully adiabatic combustion chamber and engine with different thickness of ceramic coating. Consideration of adiabatic or semi-adiabatic engine was connected with mathematical modelling of heat transfer from the cylinder gas to the cooling medium. This model takes into account changeable convection coefficient based on the experimental formulas of Woschni, heat conductivity of multi-layer walls and also small effect of radiation in SI engines. The simulation model was elaborated with full heat transfer to the cooling medium and unsteady gas flow in the engine intake and exhaust systems. The computer program taking into account 0D model of engine processes in the cylinder and 1D model of gas flow was elaborated for determination of many basic engine thermodynamic parameters for Suzuki DR-Z400S 400 cc SI engine. The paper presents calculation results of influence of the ceramic coating thickness on indicated pressure, specific fuel consumption, cooling and exhaust heat losses. Next it were presented comparisons of effective power, heat losses in the cooling and exhaust systems, total efficiency in function of engine rotational speed and also comparison of temperature inside the cylinder for standard, semi-adiabatic and full adiabatic engine. On the basis of the achieved results it was found higher total efficiency of adiabatic engines at 2500 rpm from 27% for standard engine to 37% for full adiabatic engine.

In-line stirling energy system

DOEpatents

Backhaus, Scott N [Espanola, NM; Keolian, Robert [State College, PA

2011-03-22

A high efficiency generator is provided using a Stirling engine to amplify an acoustic wave by heating the gas in the engine in a forward mode. The engine is coupled to an alternator to convert heat input to the engine into electricity. A plurality of the engines and respective alternators can be coupled to operate in a timed sequence to produce multi-phase electricity without the need for conversion. The engine system may be operated in a reverse mode as a refrigerator/heat pump.

Thermodynamics of the mesoscopic thermoelectric heat engine beyond the linear-response regime.

PubMed

Yamamoto, Kaoru; Hatano, Naomichi

2015-10-01

Mesoscopic thermoelectric heat engine is much anticipated as a device that allows us to utilize with high efficiency wasted heat inaccessible by conventional heat engines. However, the derivation of the heat current in this engine seems to be either not general or described too briefly, even inappropriately in some cases. In this paper, we give a clear-cut derivation of the heat current of the engine with suitable assumptions beyond the linear-response regime. It resolves the confusion in the definition of the heat current in the linear-response regime. After verifying that we can construct the same formalism as that of the cyclic engine, we find the following two interesting results within the Landauer-Büttiker formalism: the efficiency of the mesoscopic thermoelectric engine reaches the Carnot efficiency if and only if the transmission probability is finite at a specific energy and zero otherwise; the unitarity of the transmission probability guarantees the second law of thermodynamics, invalidating Benenti et al.'s argument in the linear-response regime that one could obtain a finite power with the Carnot efficiency under a broken time-reversal symmetry [Phys. Rev. Lett. 106, 230602 (2011)]. These results demonstrate how quantum mechanics constrains thermodynamics.

Control of aldehyde emissions in the diesel engines with alcoholic fuels.

PubMed

Krishna, M V S Murali; Varaprasad, C M; Reddy, C Venkata Ramana

2006-01-01

The major pollutants emitted from compression ignition (CI) engine with diesel as fuel are smoke and nitrogen oxides (NOx). When the diesel engine is run with alternate fuels, there is need to check alcohols (methanol or ethanol) and aldehydes also. Alcohols cannot be used directly in diesel engine and hence engine modification is essential as alcohols have low cetane number and high latent hear of vaporization. Hence, for use of alcohol in diesel engine, it needs hot combustion chamber, which is provided by low heat rejection (LHR) diesel engine with an air gap insulated piston with superni crown and air gap insulated liner with superni insert. In the present study, the pollution levels of aldehydes are reported with the use of methanol and ethanol as alternate fuels in LHR diesel engine with varying injection pressure, injection timings with different percentage of alcohol induction. The aldehydes (formaldehyde and acetaldehyde) in the exhaust were estimated by wet chemical technique with high performance liquid chromatograph (HPLC). Aldehyde emissions increased with an increase in alcohol induction. The LHR engine showed a decrease in aldehyde emissions when compared to conventional engine. However, the variation of injection pressure showed a marginal effect in reducing aldehydes, while advancing the injection timing reduced aldehyde emissions.

Survey of Thermal-Fluids Evaluation and Confirmatory Experimental Validation Requirements of Accident Tolerant Cladding Concepts with Focus on Boiling Heat Transfer Characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Nicholas R.; Wysocki, Aaron J.; Terrani, Kurt A.

The U.S. Department of Energy Office of Nuclear Energy (DOE-NE) Advanced Fuels Campaign (AFC) is working closely with the nuclear industry to develop fuel and cladding candidates with potentially enhanced accident tolerance, also known as accident tolerant fuel (ATF). Thermal-fluids characteristics are a vital element of a holistic engineering evaluation of ATF concepts. One vital characteristic related to boiling heat transfer is the critical heat flux (CHF). CHF plays a vital role in determining safety margins during normal operation and also in the progression of potential transient or accident scenarios. This deliverable is a scoping survey of thermal-fluids evaluation andmore » confirmatory experimental validation requirements of accident tolerant cladding concepts with a focus on boiling heat transfer characteristics. The key takeaway messages of this report are: 1. CHF prediction accuracy is important and the correlations may have significant uncertainty. 2. Surface conditions are important factors for CHF, primarily the wettability that is characterized by contact angle. Smaller contact angle indicates greater wettability, which increases the CHF. Surface roughness also impacts wettability. Results in the literature for pool boiling experiments indicate changes in CHF by up to 60% for several ATF cladding candidates. 3. The measured wettability of FeCrAl (i.e., contact angle and roughness) indicates that CHF should be investigated further through pool boiling and flow boiling experiments. 4. Initial measurements of static advancing contact angle and surface roughness indicate that FeCrAl is expected to have a higher CHF than Zircaloy. The measured contact angle of different FeCrAl alloy samples depends on oxide layer thickness and composition. The static advancing contact angle tends to decrease as the oxide layer thickness increases.« less

Advances in the Lightweight Air-Liquid Composite Heat Exchanger Development for Space Exploration Applications

NASA Technical Reports Server (NTRS)

Shin, E. Eugene; Johnston, J. Chris; Haas, Daniel

2011-01-01

An advanced, lightweight composite modular Air/Liquid (A/L) Heat Exchanger (HX) Prototype for potential space exploration thermal management applications was successfully designed, manufactured, and tested. This full-scale Prototype consisting of 19 modules, based on recommendations from its predecessor Engineering Development unit (EDU) but with improved thermal characteristics and manufacturability, was 11.2 % lighter than the EDU and achieves potentially a 42.7% weight reduction from the existing state-of-the-art metallic HX demonstrator. However, its higher pressure drop (0.58 psid vs. 0.16 psid of the metal HX) has to be mitigated by foam material optimizations and design modifications including a more systematic air channel design. Scalability of the Prototype design was validated experimentally by comparing manufacturability and performance between the 2-module coupon and the 19-module Prototype. The Prototype utilized the thermally conductive open-cell carbon foam material but with lower density and adopted a novel high-efficiency cooling system with significantly increased heat transfer contact surface areas, improved fabricability and manufacturability compared to the EDU. Even though the Prototype was required to meet both the thermal and the structural specifications, accomplishing the thermal requirement was a higher priority goal for this first version. Overall, the Prototype outperformed both the EDU and the corresponding metal HX, particularly in terms of specific heat transfer, but achieved 93.4% of the target. The next generation Prototype to achieve the specification target, 3,450W would need 24 core modules based on the simple scaling factor. The scale-up Prototype will weigh about 14.7 Kg vs. 21.6 Kg for the metal counterpart. The advancement of this lightweight composite HX development from the original feasibility test coupons to EDU to Prototype is discussed in this paper.

Natural Gas Engine-Driven Heat Pump Demonstration at DoD Installations: Performance and Reliability Summary

DTIC Science & Technology

2009-06-09

ER D C/ CE R L TR -0 9 -1 0 Natural Gas Engine-Driven Heat Pump Demonstration at DoD Installations Performance and Reliability Summary...L ab or at or y Approved for public release; distribution is unlimited. ERDC/CERL TR-09-10 June 2009 Natural Gas Engine-Driven Heat Pump ...CERL TR-09-10 ii Abstract: Results of field testing natural gas engine-driven heat pumps (GHP) at six southwestern U.S. Department of Defense (DoD

Hypersonic engine component experiments in high heat flux, supersonic flow environment

NASA Technical Reports Server (NTRS)

Gladden, Herbert J.; Melis, Matthew E.

1993-01-01

A major concern in advancing the state-of-the-art technologies for hypersonic vehicles is the development of an aeropropulsion system capable of withstanding the sustained high thermal loads expected during hypersonic flight. Even though progress has been made in the computational understanding of fluid dynamics and the physics/chemistry of high speed flight, there is also a need for experimental facilities capable of providing a high heat flux environment for testing component concepts and verifying/calibrating these analyses. A hydrogen/oxygen rocket engine heat source was developed at the NASA Lewis Research Center as one element in a series of facilities at national laboratories designed to fulfill this need. This 'Hot Gas Facility' is capable of providing heat fluxes up to 450 w/sq cm on flat surfaces and up to 5,000 w/sq cm at the leading edge stagnation point of a strut in a supersonic flow stream. Gas temperatures up to 3050 K can also be attained. Two recent experimental programs conducted in this facility are discussed. The objective of the first experiment is to evaluate the erosion and oxidation characteristics of a coating on a cowl leading edge (or strut leading edge) in a supersonic, high heat flux environment. Macrophotographic data from a coated leading edge model show progressive degradation over several thermal cycles at aerothermal conditions representative of high Mach number flight. The objective of the second experiment is to assess the capability of cooling a porous surface exposed to a high temperature, high velocity flow environment and to provide a heat transfer data base for a design procedure. Experimental results from transpiration cooled surfaces in a supersonic flow environment are presented.

The equivalence of minimum entropy production and maximum thermal efficiency in endoreversible heat engines.

PubMed

Haseli, Y

2016-05-01

The objective of this study is to investigate the thermal efficiency and power production of typical models of endoreversible heat engines at the regime of minimum entropy generation rate. The study considers the Curzon-Ahlborn engine, the Novikov's engine, and the Carnot vapor cycle. The operational regimes at maximum thermal efficiency, maximum power output and minimum entropy production rate are compared for each of these engines. The results reveal that in an endoreversible heat engine, a reduction in entropy production corresponds to an increase in thermal efficiency. The three criteria of minimum entropy production, the maximum thermal efficiency, and the maximum power may become equivalent at the condition of fixed heat input.

Variable Conductance Heat Pipes for Radioisotope Stirling Systems

NASA Astrophysics Data System (ADS)

Anderson, William G.; Tarau, Calin

2008-01-01

In a Stirling radioisotope system, heat must continually be removed from the GPHS modules, to maintain the GPHS modules and surrounding insulation at acceptable temperatures. Normally, the Stirling convertor provides this cooling. If the Stirling engine stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) was designed to allow multiple stops and restarts of the Stirling engine. A VCHP was designed for the Advanced Stirling Radioisotope Generator, with a 850 °C heater head temperature. The VCHP turns on with a ΔT of 30 °C, which is high enough to not risk standard ASRG operation but low enough to save most heater head life. This VCHP has a low mass, and low thermal losses for normal operation. In addition to the design, a proof-of-concept NaK VCHP was fabricated and tested. While NaK is normally not used in heat pipes, it has an advantage in that it is liquid at the reservoir operating temperature, while Na or K alone would freeze. The VCHP had two condensers, one simulating the heater head, and the other simulating the radiator. The experiments successfully demonstrated operation with the simulated heater head condenser off and on, while allowing the reservoir temperature to vary over 40 to 120 °C, the maximum range expected. In agreement with previous NaK heat pipe tests, the evaporator ΔT was roughly 70 °C, due to distillation of the NaK in the evaporator.

An analysis of the booster plume impingement environment during the space shuttle nominal staging maneuver

NASA Technical Reports Server (NTRS)

Wojciechowski, C. J.; Penny, M. M.; Greenwood, T. F.; Fossler, I. H.

1972-01-01

An experimental study of the plume impingement heating on the space shuttle booster afterbody resulting from the space shuttle orbiter engine plumes was conducted. The 1/100-scale model tests consisted of one and two orbiter engine firings on a flat plate, a flat plate with a fin, and a cylinder model. The plume impingement heating rates on these surfaces were measured using thin film heat transfer gages. Results indicate the engine simulation is a reasonable approximation to the two engine configuration, but more tests are needed to verify the plume model of the main engine configuration. For impingment, results show models experienced laminar boundary layer convective heating. Therefore, tests at higher Reynolds numbers are needed to determine impingment heating.

Advances in photonics thermal management and packaging materials

NASA Astrophysics Data System (ADS)

Zweben, Carl

2008-02-01

Heat dissipation, thermal stresses, and cost are key packaging design issues for virtually all semiconductors, including photonic applications such as diode lasers, light-emitting diodes (LEDs), solid state lighting, photovoltaics, displays, projectors, detectors, sensors and laser weapons. Heat dissipation and thermal stresses affect performance and reliability. Copper, aluminum and conventional polymeric printed circuit boards (PCBs) have high coefficients of thermal expansion, which can cause high thermal stresses. Most traditional low-coefficient-of-thermal-expansion (CTE) materials like tungsten/copper, which date from the mid 20 th century, have thermal conductivities that are no better than those of aluminum alloys, about 200 W/m-K. There are an increasing number of low-CTE materials with thermal conductivities ranging between that of copper (400 W/m-K) and 1700 W/m-K, and many other new low-CTE materials with lower thermal conductivities. An important benefit of low-CTE materials is that they allow use of hard solders. Some advanced materials are low cost. Others have the potential to be low cost in high-volume production. High-thermal-conductivity materials enable higher power levels, potentially reducing the number of required devices. Advanced thermal materials can constrain PCB CTE and greatly increase thermal conductivity. This paper reviews traditional packaging materials and advanced thermal management materials. The latter provide the packaging engineer with a greater range of options than in the past. Topics include properties, status, applications, cost, using advanced materials to fix manufacturing problems, and future directions, including composites reinforced with carbon nanotubes and other thermally conductive materials.

Heat Transfer and Fluid Dynamics Measurements in the Expansion Space of a Stirling Cycle Engine

NASA Technical Reports Server (NTRS)

Jiang, Nan; Simon, Terrence W.

2006-01-01

The heater (or acceptor) of a Stirling engine, where most of the thermal energy is accepted into the engine by heat transfer, is the hottest part of the engine. Almost as hot is the adjacent expansion space of the engine. In the expansion space, the flow is oscillatory, impinging on a two-dimensional concavely-curved surface. Knowing the heat transfer on the inside surface of the engine head is critical to the engine design for efficiency and reliability. However, the flow in this region is not well understood and support is required to develop the CFD codes needed to design modern Stirling engines of high efficiency and power output. The present project is to experimentally investigate the flow and heat transfer in the heater head region. Flow fields and heat transfer coefficients are measured to characterize the oscillatory flow as well as to supply experimental validation for the CFD Stirling engine design codes. Presented also is a discussion of how these results might be used for heater head and acceptor region design calculations.

A Feasibility Study for Advanced Technology Integration for General Aviation.

DTIC Science & Technology

1980-05-01

154 4.5.9.4 Stratified Charge Reciprocating Engine ..... .. 155 4.5.9.5 Advanced Diesel Engine . ... 158 4.5.9.6 Liquid Cooling ... ........ 159... diesel , rotary combustion engine, advanced reciprocating engine concepts. (7) Powerplant control - integrated controls, microprocessor- based controls...Research Center Topics. (1) GATE (2) Positive displacement engines (a) Advanced reciprocating engines. (b) Alternative engine systems Diesel engines

Thermal Vacuum Testing of a Novel Loop Heat Pipe Design for the Swift BAT Instrument

NASA Technical Reports Server (NTRS)

Ottenstein, Laura; Ku, Jentung; Feenan, David

2003-01-01

An advanced thermal control system for the Burst Alert Telescope on the Swift satellite has been designed and an engineering test unit (ETU) has been built and tested in a thermal vacuum chamber. The ETU assembly consists of a propylene loop heat pipe, two constant conductance heat pipes, a variable conductance heat pipe (VCHP), which is used for rough temperature control of the system, and a radiator. The entire assembly was tested in a thermal vacuum chamber at NASA/GSFC in early 2002. Tests were performed with thermal mass to represent the instrument and with electrical resistance heaters providing the heat to be transferred. Start-up and heat transfer of over 300 W was demonstrated with both steady and variable condenser sink temperatures. Radiator sink temperatures ranged from a high of approximately 273 K, to a low of approximately 83 K, and the system was held at a constant operating temperature of 278 K throughout most of the testing. A novel LHP temperature control methodology using both temperature-controlled electrical resistance heaters and a small VCHP was demonstrated. This paper describes the system and the tests performed and includes a discussion of the test results.

Enhanced heat transfer combustor technology, subtasks 1 and 2, tast C.1

NASA Technical Reports Server (NTRS)

Baily, R. D.

1986-01-01

Analytical and experimental studies are being conducted for NASA to evaluate means of increasing the heat extraction capability and service life of a liquid rocket combustor. This effort is being conducted in conjunction with other tasks to develop technologies for an advanced, expander cycle, oxygen/hydrogen engine planned for upper stage propulsion applications. Increased heat extraction, needed to raise available turbine drive energy for higher chamber pressure, is derived from combustion chamber hot gas wall ribs that increase the heat transfer surface area. Life improvement is obtained through channel designs that enhance cooling and maintain the wall temperature at an accepatable level. Laboratory test programs were conducted to evaluate the heat transfer characteristics of hot gas rib and coolant channel geometries selected through an analytical screening process. Detailed velocity profile maps, previously unavailable for rib and channel geometries, were obtained for the candidate designs using a cold flow laser velocimeter facility. Boundary layer behavior and heat transfer characteristics were determined from the velocity maps. Rib results were substantiated by hot air calorimeter testing. The flow data were analytically scaled to hot fire conditions and the results used to select two rib and three enhanced coolant channel configurations for further evaluation.

Delamination Mechanisms of Thermal and Environmental Barrier Coatings on SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Choi, Sung R.; Lee, Kang N.; Miller, Robert A.

2003-01-01

Advanced ceramic thermal harrier coatings will play an increasingly important role In future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. However, the coating durability issue remains a major concern with the ever-increasing temperature requirements. In this paper, thermal cyclic response and delamination failure modes of a ZrO2-8wt%Y2O3 and mullite/BSAS thermaVenvironmenta1 barrier coating system on SiC/SiC ceramic matrix composites were investigated using a laser high-heat-flux technique. The coating degradation and delamination processes were monitored in real time by measuring coating apparent conductivity changes during the cyclic tests under realistic engine temperature and stress gradients, utilizing the fact that delamination cracking causes an apparent decrease in the measured thermal conductivity. The ceramic coating crack initiation and propagation driving forces under the cyclic thermal loads, in conjunction with the mechanical testing results, will be discussed.

Delamination Mechanisms of Thermal and Environmental Barrier Coatings on SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Choi, Sung R.; Lee, Kang N.; Miller, Robert A.

1990-01-01

Advanced ceramic thermal barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. However, the coating durability issue remains a major concern with the ever-increasing temperature requirements. In this paper, thermal cyclic response and delamination failure modes of a ZrO2-8wt%Y2O3 and mullite/BSAS thermal/environmental barrier coating system on SiC/SiC ceramic matrix composites were investigated using a laser high-heat-flux technique. The coating degradation and delamination processes were monitored in real time by measuring coating apparent conductivity changes during the cyclic tests under realistic engine temperature and stress gradients, utilizing the fact that delamination cracking causes an apparent decrease in the measured thermal conductivity. The ceramic coating crack initiation and propagation driving forces under the cyclic thermal loads, in conjunction with the mechanical testing results, will be discussed.

Creep, Fatigue and Fracture Behavior of Environmental Barrier Coating and SiC-SiC Ceramic Matrix Composite Systems: The Role of Environment Effects

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Ghosn, Louis J.

2015-01-01

Advanced environmental barrier coating (EBC) systems for low emission SiCSiC CMC combustors and turbine airfoils have been developed to meet next generation engine emission and performance goals. This presentation will highlight the developments of NASAs current EBC system technologies for SiC-SiC ceramic matrix composite combustors and turbine airfoils, their performance evaluation and modeling progress towards improving the engine SiCSiC component temperature capability and long-term durability. Our emphasis has also been placed on the fundamental aspects of the EBC-CMC creep and fatigue behaviors, and their interactions with turbine engine oxidizing and moisture environments. The EBC-CMC environmental degradation and failure modes, under various simulated engine testing environments, in particular involving high heat flux, high pressure, high velocity combustion conditions, will be discussed aiming at quantifying the protective coating functions, performance and durability, and in conjunction with damage mechanics and fracture mechanics approaches.

On the thermodynamics of waste heat recovery from internal combustion engine exhaust gas

NASA Astrophysics Data System (ADS)

Meisner, G. P.

2013-03-01

The ideal internal combustion (IC) engine (Otto Cycle) efficiency ηIC = 1-(1/r)(γ - 1) is only a function of engine compression ratio r =Vmax/Vmin and exhaust gas specific heat ratio γ = cP/cV. Typically r = 8, γ = 1.4, and ηIC = 56%. Unlike the Carnot Cycle where ηCarnot = 1-(TC/TH) for a heat engine operating between hot and cold heat reservoirs at TH and TC, respectively, ηIC is not a function of the exhaust gas temperature. Instead, the exhaust gas temperature depends only on the intake gas temperature (ambient), r, γ, cV, and the combustion energy. The ejected exhaust gas heat is thermally decoupled from the IC engine and conveyed via the exhaust system (manifold, pipe, muffler, etc.) to ambient, and the exhaust system is simply a heat engine that does no useful work. The maximum fraction of fuel energy that can be extracted from the exhaust gas stream as useful work is (1-ηIC) × ηCarnot = 32% for TH = 850 K (exhaust) and TC = 370 K (coolant). This waste heat can be recovered using a heat engine such as a thermoelectric generator (TEG) with ηTEG> 0 in the exhaust system. A combined IC engine and TEG system can generate net useful work from the exhaust gas waste heat with efficiency ηWH = (1-ηIC) × ηCarnot ×ηTEG , and this will increase the overall fuel efficiency of the total system. Recent improvements in TEGs yield ηTEG values approaching 15% giving a potential total waste heat conversion efficiency of ηWH = 4.6%, which translates into a fuel economy improvement approaching 5%. This work is supported by the US DOE under DE-EE0005432.

Advanced Gas Turbine (AGT) Technology Project

NASA Technical Reports Server (NTRS)

1986-01-01

Engine testing, ceramic component fabrication and evaluation, component performance rig testing, and analytical studies comprised AGT 100 activities during the 1985 year. Ten experimental assemblies (builds) were evaluated using two engines. Accrued operating time was 120 hr of burning and 170 hr total, bringing cumulative total operating time to 395 hr, all devoid of major failures. Tests identified the generator seals as the primary working fluid leakage sources. Power transfer clutch operation was demonstrated. An alpha SiC gasifier rotor engine test resulted in blade tip failures. Recurring case vibration and shaft whip have limited gasifier shaft speeds to 84%. Ceramic components successfully engine tested now include the SiC scroll assembly, Si3N3 turbine rotor, combustor assembly, regenerator disk bulkhead, turbine vanes, piston rings, and couplings. A compressor shroud design change to reduce heat recirculation back to the inlet was executed. Ceramic components activity continues to focus on the development of state-of-the-art material strength characteristics in full-scale engine hardware. Fiber reinforced glass-ceramic composite turbine (inner) backplates were fabricated by Corning Glass Works. The BMAS/III material performed well in engine testing. Backplates of MAS material have not been engine tested.

Solar power plant and still

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, W.P.

This patent describes a solar energy system. It comprises: a water pond which is heated by solar energy; a cover above the pond which transmits solar energy; an air space between the pond and the cover through which warm air and vaporized water move; a chimney which induces the rapid flow of warm humid air into its lower end and delivers such air at its upper end; a fresh water heat sink which receives condensed vapor from the chimney-induced flow; a heat energy driven engine, the power output of which is a function of the temperature difference between higher andmore » lower temperature levels; a first heat exchanger in the engine connected to the top of the chimney, and arranged to convert the vapor condensation energy into the higher temperature level of th engine; a second heat exchanger in the engine arranged to provide the lower temperature of the engine by connection to the heat sink; and power transfer means driven by the temperature differential energy of the engine.« less

Mechanical Autonomous Stochastic Heat Engine

NASA Astrophysics Data System (ADS)

Serra-Garcia, Marc; Foehr, André; Molerón, Miguel; Lydon, Joseph; Chong, Christopher; Daraio, Chiara

2016-07-01

Stochastic heat engines are devices that generate work from random thermal motion using a small number of highly fluctuating degrees of freedom. Proposals for such devices have existed for more than a century and include the Maxwell demon and the Feynman ratchet. Only recently have they been demonstrated experimentally, using, e.g., thermal cycles implemented in optical traps. However, recent experimental demonstrations of classical stochastic heat engines are nonautonomous, since they require an external control system that prescribes a heating and cooling cycle and consume more energy than they produce. We present a heat engine consisting of three coupled mechanical resonators (two ribbons and a cantilever) subject to a stochastic drive. The engine uses geometric nonlinearities in the resonating ribbons to autonomously convert a random excitation into a low-entropy, nonpassive oscillation of the cantilever. The engine presents the anomalous heat transport property of negative thermal conductivity, consisting in the ability to passively transfer energy from a cold reservoir to a hot reservoir.

Mechanical Autonomous Stochastic Heat Engine.

PubMed

Serra-Garcia, Marc; Foehr, André; Molerón, Miguel; Lydon, Joseph; Chong, Christopher; Daraio, Chiara

2016-07-01

Stochastic heat engines are devices that generate work from random thermal motion using a small number of highly fluctuating degrees of freedom. Proposals for such devices have existed for more than a century and include the Maxwell demon and the Feynman ratchet. Only recently have they been demonstrated experimentally, using, e.g., thermal cycles implemented in optical traps. However, recent experimental demonstrations of classical stochastic heat engines are nonautonomous, since they require an external control system that prescribes a heating and cooling cycle and consume more energy than they produce. We present a heat engine consisting of three coupled mechanical resonators (two ribbons and a cantilever) subject to a stochastic drive. The engine uses geometric nonlinearities in the resonating ribbons to autonomously convert a random excitation into a low-entropy, nonpassive oscillation of the cantilever. The engine presents the anomalous heat transport property of negative thermal conductivity, consisting in the ability to passively transfer energy from a cold reservoir to a hot reservoir.

Quantum heat engine operating between thermal and spin reservoirs

NASA Astrophysics Data System (ADS)

Wright, Jackson S. S. T.; Gould, Tim; Carvalho, André R. R.; Bedkihal, Salil; Vaccaro, Joan A.

2018-05-01

Landauer's erasure principle is a cornerstone of thermodynamics and information theory [R. Landauer, IBM J. Res. Dev. 5, 183 (1961), 10.1147/rd.53.0183]. According to this principle, erasing information incurs a minimum energy cost. Recently, Vaccaro and Barnett [J. A. Vaccaro and S. M. Barnett, Proc. R. Soc. A 467, 1770 (2011), 10.1098/rspa.2010.0577] explored information erasure in the context of multiple conserved quantities and showed that the erasure cost can be solely in terms of spin angular momentum. As Landauer's erasure principle plays a fundamental role in heat engines, their result considerably widens the possible configurations that heat engines can have. Motivated by this, we propose here an optical heat engine that operates under a single thermal reservoir and a spin angular momentum reservoir coupled to a three-level system with two energy degenerate ground states. The proposed heat engine operates without producing waste heat and goes beyond the traditional Carnot engine where the working fluid is subjected to two thermal baths at different temperatures.

Studies of Fission Fragment Rocket Engine Propelled Spacecraft

NASA Technical Reports Server (NTRS)

Werka, Robert O.; Clark, Rodney; Sheldon, Rob; Percy, Thomas K.

2014-01-01

The NASA Office of Chief Technologist has funded from FY11 through FY14 successive studies of the physics, design, and spacecraft integration of a Fission Fragment Rocket Engine (FFRE) that directly converts the momentum of fission fragments continuously into spacecraft momentum at a theoretical specific impulse above one million seconds. While others have promised future propulsion advances if only you have the patience, the FFRE requires no waiting, no advances in physics and no advances in manufacturing processes. Such an engine unequivocally can create a new era of space exploration that can change spacecraft operation. The NIAC (NASA Institute for Advanced Concepts) Program Phase 1 study of FY11 first investigated how the revolutionary FFRE technology could be integrated into an advanced spacecraft. The FFRE combines existent technologies of low density fissioning dust trapped electrostatically and high field strength superconducting magnets for beam management. By organizing the nuclear core material to permit sufficient mean free path for escape of the fission fragments and by collimating the beam, this study showed the FFRE could convert nuclear power to thrust directly and efficiently at a delivered specific impulse of 527,000 seconds. The FY13 study showed that, without increasing the reactor power, adding a neutral gas to the fission fragment beam significantly increased the FFRE thrust through in a manner analogous to a jet engine afterburner. This frictional interaction of gas and beam resulted in an engine that continuously produced 1000 pound force of thrust at a delivered impulse of 32,000 seconds, thereby reducing the currently studied DRM 5 round trip mission to Mars from 3 years to 260 days. By decreasing the gas addition, this same engine can be tailored for much lower thrust at much higher impulse to match missions to more distant destinations. These studies created host spacecraft concepts configured for manned round trip journeys. While the vehicles are very large, they are primarily made up of a habitat payload on one end, the engine on the opposite end and a connecting spine containing radiator acreage needed to reject the heat of this powerful, but inefficient engine. These studies concluded that the engine and spacecraft are within today's technology, could be built, tested, launched on several SLS launchers, integrated, checked out, maintained at an in-space LEO base, and operated for decades just as Caribbean cruise ships operate today. The nuclear issues were found to be far less daunting that [than for] current nuclear engines. The FFRE produces very small amounts of radioactive efflux compared to their impulse, easily contained in an evacuated "bore-hole" test site. The engine poses no launch risk since it is simply a structure containing no fissionable material. The nuclear fuel is carried to orbit in containers highly crash-proofed for launch accidents from which it, in a liquid medium, is injected into the FFRE. The radioactive exhaust, with a velocity above 300 kilometers per second rapidly leaves the solar system.

Advances in LED packaging and thermal management materials

NASA Astrophysics Data System (ADS)

Zweben, Carl

2008-02-01

Heat dissipation, thermal stresses and cost are key light-emitting diode (LED) packaging issues. Heat dissipation limits power levels. Thermal stresses affect performance and reliability. Copper, aluminum and conventional polymeric printed circuit boards (PCBs) have high coefficients of thermal expansion, which can cause high thermal stresses. Most traditional low-coefficient-of-thermal-expansion (CTE) materials like tungsten/copper, which date from the mid 20th century, have thermal conductivities that are no better than those of aluminum alloys, about 200 W/m-K. An OIDA LED workshop cited a need for better thermal materials. There are an increasing number of low-CTE materials with thermal conductivities ranging between that of copper (400 W/m-K) and 1700 W/m-K, and many other low-CTE materials with lower thermal conductivities. Some of these materials are low cost. Others have the potential to be low cost in high-volume production. High-thermal-conductivity materials enable higher power levels, potentially reducing the number of required LEDs. Advanced thermal materials can constrain PCB CTE and greatly increase thermal conductivity. This paper reviews traditional packaging materials and advanced thermal management materials. The latter provide the packaging engineer with a greater range of options than in the past. Topics include properties, status, applications, cost, using advanced materials to fix manufacturing problems, and future directions, including composites reinforced with carbon nanotubes and other thermally conductive materials.

Thermodynamic efficiency analysis and cycle optimization of deeply precooled combined cycle engine in the air-breathing mode

NASA Astrophysics Data System (ADS)

Zhang, Jianqiang; Wang, Zhenguo; Li, Qinglian

2017-09-01

The efficiency calculation and cycle optimization were carried out for the Synergistic Air-Breathing Rocket Engine (SABRE) with deeply precooled combined cycle. A component-level model was developed for the engine, and exergy efficiency analysis based on the model was carried out. The methods to improve cycle efficiency have been proposed. The results indicate cycle efficiency of SABRE is between 29.7% and 41.7% along the flight trajectory, and most of the wasted exergy is occupied by the unburned hydrogen in exit gas. Exergy loss exists in each engine component, and the sum losses of main combustion chamber(CC), pre-burner(PB), precooler(PC) and 3# heat exchanger(HX3) are greater than 71.3% of the total loss. Equivalence ratio is the main influencing factor of cycle, and it can be regulated by adjusting parameters of helium loop. Increase the maximum helium outlet temperature of PC by 50 K, the total assumption of hydrogen will be saved by 4.8%, and the cycle efficiency is advanced by 3% averagely in the trajectory. Helium recirculation scheme introduces a helium recirculation loop to increase local helium flow rate of PC. It turns out the total assumption of hydrogen will be saved by 9%, that's about 1740 kg, and the cycle efficiency is advanced by 5.6% averagely.

Cooled variable nozzle radial turbine for rotor craft applications

NASA Technical Reports Server (NTRS)

Rogo, C.

1981-01-01

An advanced, small 2.27 kb/sec (5 lbs/sec), high temperature, variable area radial turbine was studied for a rotor craft application. Variable capacity cycles including single-shaft and free-turbine engine configurations were analyzed to define an optimum engine design configuration. Parametric optimizations were made on cooled and uncooled rotor configurations. A detailed structural and heat transfer analysis was conducted to provide a 4000-hour life HP turbine with material properties of the 1988 time frame. A pivoted vane and a moveable sidewall geometry were analyzed. Cooling and variable geometry penalties were included in the cycle analysis. A variable geometry free-turbine engine configuration with a design 1477K (2200 F) inlet temperature and a compressor pressure ratio of 16:1 was selected. An uncooled HP radial turbine rotor with a moveable sidewall nozzle showed the highest performance potential for a time weighted duty cycle.

A comparison of Stirling engines for use with a 25 kW dish-electric conversion system

NASA Technical Reports Server (NTRS)

Shaltens, Richard K.

1987-01-01

Two designs for an advanced Stirling conversion system (ASCS) are described. The objective of the ASCS is to generate about 25 kW of electric power to an electric utility grid at an engine/alternator target cost of $300.00/kW at the manufacturing rate of 10,000 unit/yr. Both designs contain a free-piston Stirling engine (FPSE), a heat transport system, solar receiver, a means to generate electric power, the necessary auxiliaries, and a control system. The major differences between the two concepts are: one uses a 25 kWe single-piston FPSE which incorporates a linear alternator to directly convert the energy to electricity on the utility grid; and in the second design, electrical power is generated indirectly using a hydraulic output to a ground based hydraulic motor coupled to a rotating alternator. Diagrams of the two designs are presented.

Energy efficient engine combustor test hardware detailed design report

NASA Technical Reports Server (NTRS)

Zeisser, M. H.; Greene, W.; Dubiel, D. J.

1982-01-01

The combustor for the Energy Efficient Engine is an annular, two-zone component. As designed, it either meets or exceeds all program goals for performance, safety, durability, and emissions, with the exception of oxides of nitrogen. When compared to the configuration investigated under the NASA-sponsored Experimental Clean Combustor Program, which was used as a basis for design, the Energy Efficient Engine combustor component has several technology advancements. The prediffuser section is designed with short, strutless, curved-walls to provide a uniform inlet airflow profile. Emissions control is achieved by a two-zone combustor that utilizes two types of fuel injectors to improve fuel atomization for more complete combustion. The combustor liners are a segmented configuration to meet the durability requirements at the high combustor operating pressures and temperatures. Liner cooling is accomplished with a counter-parallel FINWALL technique, which provides more effective heat transfer with less coolant.

Space electric power design study. [laser energy conversion

NASA Technical Reports Server (NTRS)

Martini, W. R.

1976-01-01

The conversion of laser energy to electrical energy is discussed. Heat engines in which the laser heats the gas inside the engine through a window as well as heat engines in which the gas is heated by a thermal energy storage reservoir which has been heated by laser radiation are both evaluated, as well as the necessary energy storage, transmission and conversion components needed for a full system. Preliminary system concepts are presented and a recommended development program is outlined. It appears possible that a free displacer Stirling engine operating directly a linear electric generator can convert 65% of the incident laser energy into electricity.

Laser engines operating by resonance absorption. [thermodynamic feasibility study

NASA Technical Reports Server (NTRS)

Garbuny, M.; Pechersky, M. J.

1976-01-01

Basic tutorial article on the thermodynamic feasibility of laser engines at the present state of the art. Three main options are considered: (1) laser power applied externally to a heat reservoir (boiler approach); (2) internal heating of working fluid by resonance absorption; and (3) direct conversion of selective excitation into work. Only (2) is considered practically feasible at present. Basic concepts and variants, efficiency relations, upper temperature limits of laser engines, selection of absorbing gases, engine walls, bleaching, thermodynamic cycles of optimized laser engines, laser-powered turbines, laser heat pumps are discussed. Photon engines and laser dissociation engines are also considered.

Performance and combustion characteristics of direct-injection stratified-charge rotary engines

NASA Technical Reports Server (NTRS)

Nguyen, Hung Lee

1987-01-01

Computer simulations of the direct-injection stratified-charge (DISC) Wankel engine have been used to calculate heat release rates and performance and efficiency characteristics of the 1007R engine. Engine pressure data have been used in a heat release analysis to study the effects of heat transfer, leakage, and crevice flows. Predicted engine performance data are compared with experimental test data over a range of engine speeds and loads. An examination of methods to improve the performance of the Wankel engine with faster combustion, reduced leakage, higher compression ratio, and turbocharging is presented.

Corrosion Issues for Ceramics in Gas Turbines

NASA Technical Reports Server (NTRS)

Jacobson, Nathan S.; Fox, Dennis S.; Smialek, James L.; Opila, Elizabeth J.; Tortorelli, Peter F.; More, Karren L.; Nickel, Klaus G.; Hirata, Takehiko; Yoshida, Makoto; Yuri, Isao

2000-01-01

The requirements for hot-gas-path materials in gas turbine engines are demanding. These materials must maintain high strength and creep resistance in a particularly aggressive environment. A typical gas turbine environment involves high temperatures, rapid gas flow rates, high pressures, and a complex mixture of aggressive gases. Figure 26.1 illustrates the requirements for components of an aircraft engine and critical issues [1]. Currently, heat engines are constructed of metal alloys, which meet these requirements within strict temperature limits. In order to extend these temperature limits, ceramic materials have been considered as potential engine materials, due to their high melting points and stability at high temperatures. These materials include oxides, carbides, borides, and nitrides. Interest in using these materials in engines appears to have begun in the 1940s with BeO-based porcelains [2]. During the 1950s, the efforts shifted to cermets. These were carbide-based materials intended to exploit the best properties of metals and ceramics. During the 1960s and 1970s, the silicon-based ceramics silicon carbide (SiC) and silicon nitride (Si3N4) were extensively developed. Although the desirable high-temperature properties of SiC and Si3N4 had long been known, consolidation of powders into component-sized bodies required the development of a series of specialized processing routes [3]. For SiC, the major consolidation routes are reaction bonding, hot-pressing, and sintering. The use of boron and carbon as additives which enable sintering was a particularly noteworthy advance [4]. For Si3N4 the major consolidation routes are reaction bonding and hot pressing [5]. Reaction-bonding involves nitridation of silicon powder. Hot pressing involves addition of various refractory oxides, such as magnesia (MgO), alumina (Al2O3), and yttria (y2O3). Variations on these processes include a number of routes including Hot Isostatic Pressing (HIP), gas-pressure sintering, sinter-HIPing, and Encapsulation-HIPing. It is important to note that each process involves the addition of secondary elements, which later were shown to dramatically influence oxidation and corrosion behavior. As dense bodies of silicon-based ceramics became more readily available, their desirable high temperature properties were confirmed. These materials retained strength to very high temperatures (i.e. 1300-1400 C). Further, they were lightweight and made from abundant materials. SiC and Si3N4 therefore emerged as leading ceramic candidates for components in heat engines, designed to operate at higher temperatures for better performance and fuel efficiency. The first US programs for ceramics in heat engines have been reviewed [6]. Selected programs on ceramic engine parts are summarized here in regard to their contributions to understanding the corrosion behavior of a heat engine environment.

Regeneratively cooled rocket engine for space storable propellants

NASA Technical Reports Server (NTRS)

Wagner, W. R.; Waldman, B. J.

1973-01-01

Analyses and experimental studies were performed with the OF2 (F2/O2)/B2H6 propellant combination over a range in operating conditions to determine suitability for a space storable pressure fed engine configuration for an extended flight space vehicle configuration. The regenerative cooling mode selected for the thrust chamber was explored in detail with the use of both the fuel and oxidizer as coolants in an advanced milled channel construction thrust chamber design operating at 100 psia chamber pressure and a nominal mixture ratio of 3.0 with a 60:1 area ratio nozzle. Benefits of the simultaneous cooling as related to gaseous injection of both fuel and oxidizer propellants were defined. Heat transfer rates, performance and combustor stability were developed for impinging element triplet injectors in uncooled copper calorimeter hardware with flow, pressure and temperature instrumentation. Evaluation of the capabilities of the B2H6 and OF2 during analytical studies and numerous tests with flow through electrically heated blocks provided design criteria for subsequent regenerative chamber design and fabrication.

Sodium heat engine system: Space application

NASA Astrophysics Data System (ADS)

Betz, Bryan H.; Sungu, Sabri; Vu, Hung V.

1994-08-01

This paper explores the possibility of utilizing the Sodium Heat Engine (SHE) or known as AMTEC (Alkali Metal Thermoelectric Converter), for electrical power generation in ``near earth'' geosynchronous orbit. The Sodium Heat Engine principle is very flexible and adapts well to a variety of physical geometries. The proposed system can be easily folded and then deployed into orbit without the need for on site assembly in space. Electric power generated from SHE engine can be used in communication satellites, in space station, and other applications such as electrical recharging of vehicles in space is one of the applications the Sodium Heat Engine could be adapted to serve.

Waste heat recovery on multiple low-speed reciprocating engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayhew, R.E.

1982-09-01

With rising fuel costs, energy conservation has taken on added significance. Installation of Waste Heat Recovery Units (WHRU) on gas turbines is one method used in the past to reduce gas plant fuel consumption. More recently, waste heat recovery on multiple reciprocating compressor engines has also been identified as having energy conservation potential. This paper reviews the development and implementation of a Waste Heat Recovery Unit (WHRU) for multiple low speed engines at the Katy Gas Plant. WHRU's for these engines should be differentiated from high speed engines and gas turbines in that low speed engines produce low frequency, highmore » amplitude pulsating exhaust. The design of a waste heat system must take this potentially destructive pulsation into account. At Katy, the pulsation forces were measured at high amplitude frequencies and then used to design structural stiffness into the various components of the WHRU to minimize vibration and improve system reliability.« less

Quantum Stirling heat engine and refrigerator with single and coupled spin systems

NASA Astrophysics Data System (ADS)

Huang, Xiao-Li; Niu, Xin-Ya; Xiu, Xiao-Ming; Yi, Xue-Xi

2014-02-01

We study the reversible quantum Stirling cycle with a single spin or two coupled spins as the working substance. With the single spin as the working substance, we find that under certain conditions the reversed cycle of a heat engine is NOT a refrigerator, this feature holds true for a Stirling heat engine with an ion trapped in a shallow potential as its working substance. The efficiency of quantum Stirling heat engine can be higher than the efficiency of the Carnot engine, but the performance coefficient of the quantum Stirling refrigerator is always lower than its classical counterpart. With two coupled spins as the working substance, we find that a heat engine can turn to a refrigerator due to the increasing of the coupling constant, this can be explained by the properties of the isothermal line in the magnetic field-entropy plane.

Development of Thin Film Thermocouples on Ceramic Materials for Advanced Propulsion System Applications

NASA Technical Reports Server (NTRS)

Holanda, R.

1992-01-01

Thin film thermocouples have been developed for use on metal parts in jet engines to 1000 c. However, advanced propulsion systems are being developed that will use ceramic materials and reach higher temperatures. The purpose of this work is to develop thin film thermocouples for use on ceramic materials. The new thin film thermocouples are Pt13Rh/Pt fabricated by the sputtering process. Lead wires are attached using the parallel-gap welding process. The ceramic materials tested are silicon nitride, silicon carbide, aluminum oxide, and mullite. Both steady state and thermal cycling furnace tests were performed in the temperature range to 1500 C. High-heating-rate tests were performed in an arc lamp heat-flux-calibration facility. The fabrication of the thin film thermocouples is described. The thin film thermocouple output was compared to a reference wire thermocouple. Drift of the thin film thermocouples was determined, and causes of drift are discussed. The results of high heating rate tests up to 2500 C/sec are presented. The stability of the ceramic materials is examined. It is concluded that Pt13Rh/Pt thin film thermocouples are capable of meeting lifetime goals of 50 hours or more up to temperature of 1500 C depending on the stability of the particular ceramic substrate.

Development of thin film thermocouples on ceramic materials for advanced propulsion system applications

NASA Technical Reports Server (NTRS)

Holanda, Raymond

1993-01-01

Thin film thermocouples were developed for use on metal parts in jet engines to 1000 C. However, advanced propulsion systems are being developed that will use ceramic materials and reach higher temperatures. The purpose is to develop thin film thermocouples for use on ceramic materials. The new thin film thermocouples are Pt13Rh/Pt fabricated by the sputtering process. Lead wires are attached using the parallel-gap welding process. The ceramic materials tested are silicon nitride, silicon carbide, aluminum oxide, and mullite. Both steady state and thermal cycling furnace tests were performed in the temperature range to 1500 C. High-heating-rate tests were performed in an arc lamp heat-flux-calibration facility. The fabrication of the thin film thermocouples is described. The thin film thermocouple output was compared to a reference wire thermocouple. Drift of the thin film thermocouples was determined, and causes of drift are discussed. The results of high heating rate tests up to 2500 C/sec are presented. The stability of the ceramic materials is examined. It is concluded that Pt13Rh/Pt thin film thermocouples are capable of meeting lifetime goals of 50 hr or more up to temperatures of 1500 C depending on the stability of the particular ceramic substrate.

A hydrogen-oxygen rocket engine coolant passage design program (RECOP) for fluid-cooled thrust chambers and nozzles

NASA Technical Reports Server (NTRS)

Tomsik, Thomas M.

1994-01-01

The design of coolant passages in regeneratively cooled thrust chambers is critical to the operation and safety of a rocket engine system. Designing a coolant passage is a complex thermal and hydraulic problem requiring an accurate understanding of the heat transfer between the combustion gas and the coolant. Every major rocket engine company has invested in the development of thrust chamber computer design and analysis tools; two examples are Rocketdyne's REGEN code and Aerojet's ELES program. In an effort to augment current design capabilities for government and industry, the NASA Lewis Research Center is developing a computer model to design coolant passages for advanced regeneratively cooled thrust chambers. The RECOP code incorporates state-of-the-art correlations, numerical techniques and design methods, certainly minimum requirements for generating optimum designs of future space chemical engines. A preliminary version of the RECOP model was recently completed and code validation work is in progress. This paper introduces major features of RECOP and compares the analysis to design points for the first test case engine; the Pratt & Whitney RL10A-3-3A thrust chamber.

Systems Simulation of NASA Shooting Star Experiment Using Matlab/Simulink

NASA Technical Reports Server (NTRS)

Reagan, Shawn

1997-01-01

The Shooting Star Experiment (SSE) is an experiment that incorporates advance propulsion technology. This project is being managed by the Marshall Space Flight Center, Huntsville, Alabama. Whenever spacecraft are launched from Low Earth Orbit (LEO), (typically 150 nautical miles) they are powered by a upper propulsive stage utilizing either a solid or liquid propellant engine. A typically mission for a spacecraft utilizing an upper stage would be a transfer from LEO to a Geostationary Orbit (GEO) or an interplanetary mission. These upper stages are heavy and bulky because they must carry propellants to provide sufficient energy to perform the mission. The SSE utilizes the energy of the Sun by focusing this energy by means of a Frensel lens into an engine where hydrogen (or nitrogen) gas is injected. The focusing of the solar energy heats the engine to very high temperatures. When the gas is injected into the hot engine, the gas is expelled at very high velocities. This process is extremely efficient. Because of the efficiency of the SSE type engine, more payload can be carried for a typical mission since the propulsive element is much smaller.

Performance of discrete heat engines and heat pumps in finite time

PubMed

Feldmann; Kosloff

2000-05-01

The performance in finite time of a discrete heat engine with internal friction is analyzed. The working fluid of the engine is composed of an ensemble of noninteracting two level systems. External work is applied by changing the external field and thus the internal energy levels. The friction induces a minimal cycle time. The power output of the engine is optimized with respect to time allocation between the contact time with the hot and cold baths as well as the adiabats. The engine's performance is also optimized with respect to the external fields. By reversing the cycle of operation a heat pump is constructed. The performance of the engine as a heat pump is also optimized. By varying the time allocation between the adiabats and the contact time with the reservoir a universal behavior can be identified. The optimal performance of the engine when the cold bath is approaching absolute zero is studied. It is found that the optimal cooling rate converges linearly to zero when the temperature approaches absolute zero.

Performance analysis of exhaust heat recovery using organic Rankine cycle in a passenger car with a compression ignition engine

NASA Astrophysics Data System (ADS)

Ghilvacs, M.; Prisecaru, T.; Pop, H.; Apostol, V.; Prisecaru, M.; Pop, E.; Popescu, Gh; Ciobanu, C.; Mohanad, A.; Alexandru, A.

2016-08-01

Compression ignition engines transform approximately 40% of the fuel energy into power available at the crankshaft, while the rest part of the fuel energy is lost as coolant, exhaust gases and other waste heat. An organic Rankine cycle (ORC) can be used to recover this waste heat. In this paper, the characteristics of a system combining a compression ignition engine with an ORC which recover the waste heat from the exhaust gases are analyzed. The performance map of the diesel engine is measured on an engine test bench and the heat quantities wasted by the exhaust gases are calculated over the engine's entire operating region. Based on this data, the working parameters of ORC are defined, and the performance of a combined engine-ORC system is evaluated across this entire region. The results show that the net power of ORC is 6.304kW at rated power point and a maximum of 10% reduction in brake specific fuel consumption can be achieved.

Reversible Quantum Brownian Heat Engines for Electrons

NASA Astrophysics Data System (ADS)

Humphrey, T. E.; Newbury, R.; Taylor, R. P.; Linke, H.

2002-08-01

Brownian heat engines use local temperature gradients in asymmetric potentials to move particles against an external force. The energy efficiency of such machines is generally limited by irreversible heat flow carried by particles that make contact with different heat baths. Here we show that, by using a suitably chosen energy filter, electrons can be transferred reversibly between reservoirs that have different temperatures and electrochemical potentials. We apply this result to propose heat engines based on mesoscopic semiconductor ratchets, which can quasistatically operate arbitrarily close to Carnot efficiency.

Reversible quantum heat engines for electrons

NASA Astrophysics Data System (ADS)

Linke, Heiner; Humphrey, Tammy E.; Newbury, Richard; Taylor, Richard P.

2002-03-01

Brownian heat engines use local temperature gradients in asymmetric potentials to move particles against an external force. The energy efficiency of such machines is generally limited by irreversible heat flow carried by particles that make contact with different heat baths. Here we show that, by using a suitably chosen energy filter, electrons can be transferred reversibly between reservoirs that have different temperatures and electrochemical potentials. We apply this result to propose heat engines based on quantum ratchets, which can quasistatically operate at Carnot efficiency.

Disk Alloy Development

NASA Technical Reports Server (NTRS)

Gabb, Tim; Gayda, John; Telesman, Jack

2001-01-01

The advanced powder metallurgy disk alloy ME3 was designed using statistical screening and optimization of composition and processing variables in the NASA HSR/EPM disk program to have extended durability at 1150 to 1250 "Fin large disks. Scaled-up disks of this alloy were produced at the conclusion of this program to demonstrate these properties in realistic disk shapes. The objective of the UEET disk program was to assess the mechanical properties of these ME3 disks as functions of temperature, in order to estimate the maximum temperature capabilities of this advanced alloy. Scaled-up disks processed in the HSR/EPM Compressor / Turbine Disk program were sectioned, machined into specimens, and tested in tensile, creep, fatigue, and fatigue crack growth tests by NASA Glenn Research Center, in cooperation with General Electric Engine Company and Pratt & Whitney Aircraft Engines. Additional sub-scale disks and blanks were processed and tested to explore the effects of several processing variations on mechanical properties. Scaled-up disks of an advanced regional disk alloy, Alloy 10, were used to evaluate dual microstructure heat treatments. This allowed demonstration of an improved balance of properties in disks with higher strength and fatigue resistance in the bores and higher creep and dwell fatigue crack growth resistance in the rims. Results indicate the baseline ME3 alloy and process has 1300 to 1350 O F temperature capabilities, dependent on detailed disk and engine design property requirements. Chemistry and process enhancements show promise for further increasing temperature capabilities.

Optimal power and efficiency of quantum Stirling heat engines

NASA Astrophysics Data System (ADS)

Yin, Yong; Chen, Lingen; Wu, Feng

2017-01-01

A quantum Stirling heat engine model is established in this paper in which imperfect regeneration and heat leakage are considered. A single particle which contained in a one-dimensional infinite potential well is studied, and the system consists of countless replicas. Each particle is confined in its own potential well, whose occupation probabilities can be expressed by the thermal equilibrium Gibbs distributions. Based on the Schrödinger equation, the expressions of power output and efficiency for the engine are obtained. Effects of imperfect regeneration and heat leakage on the optimal performance are discussed. The optimal performance region and the optimal values of important parameters of the engine cycle are obtained. The results obtained can provide some guidelines for the design of a quantum Stirling heat engine.

Thermodynamics of the mesoscopic thermoelectric heat engine beyond the linear-response regime

NASA Astrophysics Data System (ADS)

Yamamoto, Kaoru; Hatano, Naomichi

2015-10-01

Mesoscopic thermoelectric heat engine is much anticipated as a device that allows us to utilize with high efficiency wasted heat inaccessible by conventional heat engines. However, the derivation of the heat current in this engine seems to be either not general or described too briefly, even inappropriately in some cases. In this paper, we give a clear-cut derivation of the heat current of the engine with suitable assumptions beyond the linear-response regime. It resolves the confusion in the definition of the heat current in the linear-response regime. After verifying that we can construct the same formalism as that of the cyclic engine, we find the following two interesting results within the Landauer-Büttiker formalism: the efficiency of the mesoscopic thermoelectric engine reaches the Carnot efficiency if and only if the transmission probability is finite at a specific energy and zero otherwise; the unitarity of the transmission probability guarantees the second law of thermodynamics, invalidating Benenti et al.'s argument in the linear-response regime that one could obtain a finite power with the Carnot efficiency under a broken time-reversal symmetry [Phys. Rev. Lett. 106, 230602 (2011), 10.1103/PhysRevLett.106.230602]. These results demonstrate how quantum mechanics constrains thermodynamics.

Methods for heat transfer and temperature field analysis of the insulated diesel phase 2 progress report

NASA Technical Reports Server (NTRS)

Morel, T.; Kerlbar, R.; Fort, E. F.; Blumberg, P. N.

1985-01-01

This report describes work done during Phase 2 of a 3 year program aimed at developing a comprehensive heat transfer and thermal analysis methodology for design analysis of insulated diesel engines. The overall program addresses all the key heat transfer issues: (1) spatially and time-resolved convective and radiative in-cylinder heat transfer, (2) steady-state conduction in the overall structure, and (3) cyclical and load/speed temperature transients in the engine structure. During Phase 2, radiation heat transfer model was developed, which accounts for soot formation and burn up. A methodology was developed for carrying out the multi-dimensional finite-element heat conduction calculations within the framework of thermodynamic cycle codes. Studies were carried out using the integrated methodology to address key issues in low heat rejection engines. A wide ranging design analysis matrix was covered, including a variety of insulation strategies, recovery devices and base engine configurations. A single cylinder Cummins engine was installed at Purdue University, and it was brought to a full operational status. The development of instrumentation was continued, concentrating on radiation heat flux detector, total heat flux probe, and accurate pressure-crank angle data acquisition.

Exergy analysis of electrically- and thermally-driven engines to drive heat pumps: An exhaustive comparative study

DOE PAGES

Ally, Moonis R.; Sharma, Vishaldeep; Abdelaziz, Omar

2017-02-21

The choice of driving a heat pump with an electrically$-$or a thermally-driven engine is a vexing question complicated by the carbon footprint and environmental impact of using electricity versus natural gas (or waste heat) as the main driver for the respective engines. The amount of useful work generated by these two distinct engines is the focal point of this paper, which addresses a key question: which engine presents a better choice for a given heat pumping application within the constraints of energy and environmental stewardship? Extensive use of energy, exergy, and availability analysis is necessary to quantify the useful workmore » and to examine the issue holistically for both types of engines. The methodology explains why the output of work from these two distinct engines to satisfy a given load is vastly different, a direct consequence of their inherent Irreversibility. Thermodynamic consistency is guaranteed by satisfaction of the First and Second Laws applied to closed systems and their subsystems. The general conclusion is that thermally-driven engines are not industrious converters of heat to mechanical work.« less

Exergy analysis of electrically- and thermally-driven engines to drive heat pumps: An exhaustive comparative study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ally, Moonis R.; Sharma, Vishaldeep; Abdelaziz, Omar

The choice of driving a heat pump with an electrically$-$or a thermally-driven engine is a vexing question complicated by the carbon footprint and environmental impact of using electricity versus natural gas (or waste heat) as the main driver for the respective engines. The amount of useful work generated by these two distinct engines is the focal point of this paper, which addresses a key question: which engine presents a better choice for a given heat pumping application within the constraints of energy and environmental stewardship? Extensive use of energy, exergy, and availability analysis is necessary to quantify the useful workmore » and to examine the issue holistically for both types of engines. The methodology explains why the output of work from these two distinct engines to satisfy a given load is vastly different, a direct consequence of their inherent Irreversibility. Thermodynamic consistency is guaranteed by satisfaction of the First and Second Laws applied to closed systems and their subsystems. The general conclusion is that thermally-driven engines are not industrious converters of heat to mechanical work.« less

Gasoline Combustion Fundamentals DOE FY17 Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ekoto, Isaac W.

Advanced automotive gasoline engines that leverage a combination of reduced heat transfer, throttling, and mechanical losses; shorter combustion durations; and higher compression and mixture specific heat ratios are needed to meet aggressive DOE VTP fuel economy and pollutant emission targets. Central challenges include poor combustion stability at low-power conditions when large amounts of charge dilution are introduced and high sensitivity of conventional inductive coil ignition systems to elevated charge motion and density for boosted high-load operation. For conventional spark ignited operation, novel low-temperature plasma (LTP) or pre-chamber based ignition systems can improve dilution tolerances while maintaining good performance characteristics atmore » elevated charge densities. Moreover, these igniters can improve the control of advanced compression ignition (ACI) strategies for gasoline at low to moderate loads. The overarching research objective of the Gasoline Combustion Fundamentals project is to investigate phenomenological aspects related to enhanced ignition. The objective is accomplished through targeted experiments performed in a single-cylinder optically accessible research engine or an in-house developed optically accessible spark calorimeter (OASC). In situ optical diagnostics and ex situ gas sampling measurements are performed to elucidate important details of ignition and combustion processes. Measurements are further used to develop and validate complementary high-fidelity ignition simulations. The primary project audience is automotive manufacturers, Tier 1 suppliers, and technology startups—close cooperation has resulted in the development and execution of project objectives that address crucial mid- to long-range research challenges.« less

Improved silicon carbide for advanced heat engines

NASA Technical Reports Server (NTRS)

Whalen, Thomas J.

1989-01-01

The development of high strength, high reliability silicon carbide parts with complex shapes suitable for use in advanced heat engines is studied. Injection molding was the forming method selected for the program because it is capable of forming complex parts adaptable for mass production on an economically sound basis. The goals were to reach a Weibull characteristic strength of 550 MPa (80 ksi) and a Weibull modulus of 16 for bars tested in four-point loading. Statistically designed experiments were performed throughout the program and a fluid mixing process employing an attritor mixer was developed. Compositional improvements in the amounts and sources of boron and carbon used and a pressureless sintering cycle were developed which provided samples of about 99 percent of theoretical density. Strengths were found to improve significantly by annealing in air. Strengths in excess of 550 MPa (80 ksi) with Weibull modulus of about 9 were obtained. Further improvements in Weibull modulus to about 16 were realized by proof testing. This is an increase of 86 percent in strength and 100 percent in Weibull modulus over the baseline data generated at the beginning of the program. Molding yields were improved and flaw distributions were observed to follow a Poisson process. Magic angle spinning nuclear magnetic resonance spectra were found to be useful in characterizing the SiC powder and the sintered samples. Turbocharger rotors were molded and examined as an indication of the moldability of the mixes which were developed in this program.

Study of advanced fuel system concepts for commercial aircraft and engines

NASA Technical Reports Server (NTRS)

Versaw, E. F.; Brewer, G. D.; Byers, W. D.; Fogg, H. W.; Hanks, D. E.; Chirivella, J.

1983-01-01

The impact on a commercial transport aircraft of using fuels which have relaxed property limits relative to current commercial jet fuel was assessed. The methodology of the study is outlined, fuel properties are discussed, and the effect of the relaxation of fuel properties analyzed. Advanced fuel system component designs that permit the satisfactory use of fuel with the candidate relaxed properties in the subject aircraft are described. The two fuel properties considered in detail are freezing point and thermal stability. Three candidate fuel system concepts were selected and evaluated in terms of performance, cost, weight, safety, and maintainability. A fuel system that incorporates insulation and electrical heating elements on fuel tank lower surfaces was found to be most cost effective for the long term.

Methods for heat transfer and temperature field analysis of the insulated diesel, phase 3

NASA Technical Reports Server (NTRS)

Morel, Thomas; Wahiduzzaman, Syed; Fort, Edward F.; Keribar, Rifat; Blumberg, Paul N.

1988-01-01

Work during Phase 3 of a program aimed at developing a comprehensive heat transfer and thermal analysis methodology for design analysis of insulated diesel engines is described. The overall program addresses all the key heat transfer issues: (1) spatially and time-resolved convective and radiative in-cylinder heat transfer, (2) steady-state conduction in the overall structure, and (3) cyclical and load/speed temperature transients in the engine structure. These are all accounted for in a coupled way together with cycle thermodynamics. This methodology was developed during Phases 1 and 2. During Phase 3, an experimental program was carried out to obtain data on heat transfer under cooled and insulated engine conditions and also to generate a database to validate the developed methodology. A single cylinder Cummins diesel engine was instrumented for instantaneous total heat flux and heat radiation measurements. Data were acquired over a wide range of operating conditions in two engine configurations. One was a cooled baseline. The other included ceramic coated components (0.050 inches plasma sprayed zirconia)-piston, head and valves. The experiments showed that the insulated engine has a smaller heat flux than the cooled one. The model predictions were found to be in very good agreement with the data.

Turbulent heat transfer prediction method for application to scramjet engines

NASA Technical Reports Server (NTRS)

Pinckney, S. Z.

1974-01-01

An integral method for predicting boundary layer development in turbulent flow regions on two-dimensional or axisymmetric bodies was developed. The method has the capability of approximating nonequilibrium velocity profiles as well as the local surface friction in the presence of a pressure gradient. An approach was developed for the problem of predicting the heat transfer in a turbulent boundary layer in the presence of a high pressure gradient. The solution was derived with particular emphasis on its applicability to supersonic combustion; thus, the effects of real gas flows were included. The resulting integrodifferential boundary layer method permits the estimation of cooling reguirements for scramjet engines. Theoretical heat transfer results are compared with experimental combustor and noncombustor heat transfer data. The heat transfer method was used in the development of engine design concepts which will produce an engine with reduced cooling requirements. The Langley scramjet engine module was designed by utilizing these design concepts and this engine design is discussed along with its corresponding cooling requirements. The heat transfer method was also used to develop a combustor cooling correlation for a combustor whose local properties are computed one dimensionally by assuming a linear area variation and a given heat release schedule.

Exhaust heated hydrogen and oxygen producing catalytic converter for combustion engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schreiber, E.T.

1977-07-26

A steam generator is provided in operative association with a source of water and the exhaust system of a combustion engine including an air induction system provided with primary fuel inlet structure and supplemental fuel inlet structure. The steam generator derives its heat for converting water into steam from the exhaust system of the combustion engine and the steam generator includes a steam outlet communicated with and opening into one end of an elongated tubular housing disposed in good heat transfer relation with the exhaust system of the combustion engine and having a gas outlet at its other end communicatedmore » with the supplemental fuel inlet of the induction system. The tubular housing has iron filings disposed therein and is in such heat transfer relation with the exhaust system of the combustion engine so as to elevate the temperature of steam passing therethrough and to heat the iron filings to the extent that passage of the heated steam over the heated filings will result in hydrogen and oxygen gas being produced in the tubular housing for subsequent passage to the supplemental fuel inlet of the combustion engine induction system.« less

Weighted reciprocal of temperature, weighted thermal flux, and their applications in finite-time thermodynamics.

PubMed

Sheng, Shiqi; Tu, Z C

2014-01-01

The concepts of weighted reciprocal of temperature and weighted thermal flux are proposed for a heat engine operating between two heat baths and outputting mechanical work. With the aid of these two concepts, the generalized thermodynamic fluxes and forces can be expressed in a consistent way within the framework of irreversible thermodynamics. Then the efficiency at maximum power output for a heat engine, one of key topics in finite-time thermodynamics, is investigated on the basis of a generic model under the tight-coupling condition. The corresponding results have the same forms as those of low-dissipation heat engines [ M. Esposito, R. Kawai, K. Lindenberg and C. Van den Broeck Phys. Rev. Lett. 105 150603 (2010)]. The mappings from two kinds of typical heat engines, such as the low-dissipation heat engine and the Feynman ratchet, into the present generic model are constructed. The universal efficiency at maximum power output up to the quadratic order is found to be valid for a heat engine coupled symmetrically and tightly with two baths. The concepts of weighted reciprocal of temperature and weighted thermal flux are also transplanted to the optimization of refrigerators.

Thermodynamic feature of a Brownian heat engine operating between two heat baths.

PubMed

Asfaw, Mesfin

2014-01-01

A generalized theory of nonequilibrium thermodynamics for a Brownian motor operating between two different heat baths is presented. Via a simple paradigmatic model, we not only explore the thermodynamic feature of the engine in the regime of the nonequilibrium steady state but also study the short time behavior of the system for either the isothermal case with load or, in general, the nonisothermal case with or without load. Many elegant thermodynamic theories can be checked via the present model. Furthermore the dependence of the velocity, the efficiency, and the performance of the refrigerator on time t is examined. Our study reveals a current reversal due to time t. In the early system relaxation period, the model works neither as a heat engine nor as a refrigerator and only after a certain period of time does the model start functioning as a heat engine or as a refrigerator. The performance of the engine also improves with time and at steady state the engine manifests a higher efficiency or performance as a refrigerator. Furthermore the effect of energy exchange via the kinetic energy on the performance of the heat engine is explored.

Assessment of the TRACE Reactor Analysis Code Against Selected PANDA Transient Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zavisca, M.; Ghaderi, M.; Khatib-Rahbar, M.

2006-07-01

The TRACE (TRAC/RELAP Advanced Computational Engine) code is an advanced, best-estimate thermal-hydraulic program intended to simulate the transient behavior of light-water reactor systems, using a two-fluid (steam and water, with non-condensable gas), seven-equation representation of the conservation equations and flow-regime dependent constitutive relations in a component-based model with one-, two-, or three-dimensional elements, as well as solid heat structures and logical elements for the control system. The U.S. Nuclear Regulatory Commission is currently supporting the development of the TRACE code and its assessment against a variety of experimental data pertinent to existing and evolutionary reactor designs. This paper presents themore » results of TRACE post-test prediction of P-series of experiments (i.e., tests comprising the ISP-42 blind and open phases) conducted at the PANDA large-scale test facility in 1990's. These results show reasonable agreement with the reported test results, indicating good performance of the code and relevant underlying thermal-hydraulic and heat transfer models. (authors)« less

Efficiency of Brownian heat engines.

PubMed

Derényi, I; Astumian, R D

1999-06-01

We study the efficiency of one-dimensional thermally driven Brownian ratchets or heat engines. We identify and compare the three basic setups characterized by the type of the connection between the Brownian particle and the two heat reservoirs: (i) simultaneous, (ii) alternating in time, and (iii) position dependent. We make a clear distinction between the heat flow via the kinetic and the potential energy of the particle, and show that the former is always irreversible and it is only the third setup where the latter is reversible when the engine works quasistatically. We also show that in the third setup the heat flow via the kinetic energy can be reduced arbitrarily, proving that even for microscopic heat engines there is no fundamental limit of the efficiency lower than that of a Carnot cycle.

Advanced Thermal Barrier and Environmental Barrier Coating Development at NASA GRC

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Robinson, Craig

2017-01-01

This presentation summarizes NASA's advanced thermal barrier and environmental barrier coating systems, and the coating performance improvements that has recently been achieved and documented in laboratory simulated rig test conditions. One of the emphases has been placed on the toughness and impact resistance enhancements of the low conductivity, defect cluster thermal barrier coating systems. The advances in the next generation environmental barrier coatings for SiCSiC ceramic matrix composites have also been highlighted, particularly in the design of a new series of oxide-silicate composition systems to be integrated with next generation SiC-SiC turbine engine components for 2700F coating applications. Major technical barriers in developing the thermal and environmental barrier coating systems are also described. The performance and model validations in the rig simulated turbine combustion, heat flux, steam and calcium-magnesium-aluminosilicate (CMAS) environments have helped the current progress in improved temperature capability, environmental stability, and long-term fatigue-environment system durability of the advanced thermal and environmental barrier coating systems.

Heat engine development for solar thermal power systems

NASA Astrophysics Data System (ADS)

Pham, H. Q.; Jaffe, L. D.

The parabolic dish solar collector systems for converting sunlight to electrical power through a heat engine will, require a small heat engine of high performance long lifetime to be competitive with conventional power systems. The most promising engine candidates are Stirling, high temperature Brayton, and combined cycle. Engines available in the current market today do not meet these requirements. The development of Stirling and high temperature Brayton for automotive applications was studied which utilizes much of the technology developed in this automotive program for solar power engines. The technical status of the engine candidates is reviewed and the components that may additional development to meet solar thermal system requirements are identified.

Heat Exchanger Lab for Chemical Engineering Undergraduates

ERIC Educational Resources Information Center

Rajala, Jonathan W.; Evans, Edward A.; Chase, George G.

2015-01-01

Third year chemical engineering undergraduate students at The University of Akron designed and fabricated a heat exchanger for a stirred tank as part of a Chemical Engineering Laboratory course. The heat exchanger portion of this course was three weeks of the fifteen week long semester. Students applied concepts of scale-up and dimensional…

Principles of liquids working in heat engines

PubMed Central

Allen, P. C.; Knight, W. R.; Paulson, D. N.; Wheatley, J. C.

1980-01-01

The thermodynamic and thermophysical properties of liquids suggest that they should be powerful working fluids in heat engines. Their use requires heat engines based conceptually on the Stirling and Malone principles. The principles are explained, and then experiments on propylene are presented that demonstrate the principles and confirm the thermodynamic analysis. PMID:16592756

A numerical model on thermodynamic analysis of free piston Stirling engines

NASA Astrophysics Data System (ADS)

Mou, Jian; Hong, Guotong

2017-02-01

In this paper, a new numerical thermodynamic model which bases on the energy conservation law has been used to analyze the free piston Stirling engine. In the model all data was taken from a real free piston Stirling engine which has been built in our laboratory. The energy conservation equations have been applied to expansion space and compression space of the engine. The equation includes internal energy, input power, output power, enthalpy and the heat losses. The heat losses include regenerative heat conduction loss, shuttle heat loss, seal leakage loss and the cavity wall heat conduction loss. The numerical results show that the temperature of expansion space and the temperature of compression space vary with the time. The higher regeneration effectiveness, the higher efficiency and bigger output work. It is also found that under different initial pressures, the heat source temperature, phase angle and engine work frequency pose different effects on the engine’s efficiency and power. As a result, the model is expected to be a useful tool for simulation, design and optimization of Stirling engines.

Superconductor Particles As The Working Media Of A Heat Engine

NASA Astrophysics Data System (ADS)

Keefe, Peter D.

2011-12-01

A heat engine is presented in which the working media comprises a multiplicity of mutually isolated particles of Type I superconductor which are selectively processed through H-T phase space so as to convert a heat influx from a high temperature heat reservoir into a useful work output, wherein no heat is rejected to a low temperature heat reservoir.

ETR HEAT EXCHANGER BUILDING, TRA644. WORKERS ARE INSTALLING HEAT EXCHANGER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR HEAT EXCHANGER BUILDING, TRA-644. WORKERS ARE INSTALLING HEAT EXCHANGER PIPING. INL NEGATIVE NO. 56-3122. Jack L. Anderson, Photographer, 9/21/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Control system for, and a method of, heating an operator station of a work machine

DOEpatents

Baker, Thomas M.; Hoff, Brian D.; Akasam, Sivaprasad

2005-04-05

There are situations in which an operator remains in an operator station of a work machine when an engine of the work machine is inactive. The present invention includes a control system for, and a method of, heating the operator station when the engine is inactive. A heating system of the work machine includes an electrically-powered coolant pump, a power source, and at least one piece of warmed machinery. An operator heat controller is moveable between a first and a second position, and is operable to connect the electrically-powered coolant pump to the power source when the engine is inactive and the operator heat controller is in the first position. Thus, by deactivating the engine and then moving the operator heat controller to the first position, the operator may supply electrical energy to the electrically-powered coolant pump, which is operably coupled to heat the operator station.

An analytical study of hybrid ejector/internal combustion engine-driven heat pumps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murphy, R.W.

1988-01-01

Because ejectors can combine high reliability with low maintenance cost in a package requiring little capital investment, they may provide attractive heat pumping capability in situations where the importance of their inefficiencies is minimized. One such concept, a hybrid system in which an ejector driven by engine reject heat is used to increase the performance of an internal combustion engine-driven heat pump, was analyzed by modifying an existing ejector heat pump model and combining it with generic compressor and internal combustion engine models. Under the model assumptions for nominal cooling mode conditions, the results showed that hybrid systems could providemore » substantial performance augmentation/emdash/up to 17/percent/ increase in system coefficient of performance for a parallel arrangement of an enhanced ejector with the engine-driven compressor. 4 refs., 4 figs., 4 tabs.« less

A global model for steady state and transient S.I. engine heat transfer studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bohac, S.V.; Assanis, D.N.; Baker, D.M.

1996-09-01

A global, systems-level model which characterizes the thermal behavior of internal combustion engines is described in this paper. Based on resistor-capacitor thermal networks, either steady-state or transient thermal simulations can be performed. A two-zone, quasi-dimensional spark-ignition engine simulation is used to determine in-cylinder gas temperature and convection coefficients. Engine heat fluxes and component temperatures can subsequently be predicted from specification of general engine dimensions, materials, and operating conditions. Emphasis has been placed on minimizing the number of model inputs and keeping them as simple as possible to make the model practical and useful as an early design tool. The successmore » of the global model depends on properly scaling the general engine inputs to accurately model engine heat flow paths across families of engine designs. The development and validation of suitable, scalable submodels is described in detail in this paper. Simulation sub-models and overall system predictions are validated with data from two spark ignition engines. Several sensitivity studies are performed to determine the most significant heat transfer paths within the engine and exhaust system. Overall, it has been shown that the model is a powerful tool in predicting steady-state heat rejection and component temperatures, as well as transient component temperatures.« less

Modeling the emissions of a dual fuel engine coupled with a biomass gasifier-supplementing the Wiebe function.

PubMed

Vakalis, Stergios; Caligiuri, Carlo; Moustakas, Konstantinos; Malamis, Dimitris; Renzi, Massimiliano; Baratieri, Marco

2018-03-12

There is a growing market demand for small-scale biomass gasifiers that is driven by the economic incentives and the legislative framework. Small-scale gasifiers produce a gaseous fuel, commonly referred to as producer gas, with relatively low heating value. Thus, the most common energy conversion systems that are coupled with small-scale gasifiers are internal combustion engines. In order to increase the electrical efficiency, the operators choose dual fuel engines and mix the producer gas with diesel. The Wiebe function has been a valuable tool for assessing the efficiency of dual fuel internal combustion engines. This study introduces a thermodynamic model that works in parallel with the Wiebe function and calculates the emissions of the engines. This "vis-à-vis" approach takes into consideration the actual conditions inside the cylinders-as they are returned by the Wiebe function-and calculates the final thermodynamic equilibrium of the flue gases mixture. This approach aims to enhance the operation of the dual fuel internal combustion engines by identifying the optimal operating conditions and-at the same time-advance pollution control and minimize the environmental impact.

Design of a Nanoscale, CMOS-Integrable, Thermal-Guiding Structure for Boolean-Logic and Neuromorphic Computation.

PubMed

Loke, Desmond; Skelton, Jonathan M; Chong, Tow-Chong; Elliott, Stephen R

2016-12-21

One of the requirements for achieving faster CMOS electronics is to mitigate the unacceptably large chip areas required to steer heat away from or, more recently, toward the critical nodes of state-of-the-art devices. Thermal-guiding (TG) structures can efficiently direct heat by "meta-materials" engineering; however, some key aspects of the behavior of these systems are not fully understood. Here, we demonstrate control of the thermal-diffusion properties of TG structures by using nanometer-scale, CMOS-integrable, graphene-on-silica stacked materials through finite-element-methods simulations. It has been shown that it is possible to implement novel, controllable, thermally based Boolean-logic and spike-timing-dependent plasticity operations for advanced (neuromorphic) computing applications using such thermal-guide architectures.