Materials technology assessment for stirling engines

NASA Technical Reports Server (NTRS)

Stephens, J. R.; Witzke, W. R.; Watson, G. K.; Johnston, J. R.; Croft, W. J.

1977-01-01

A materials technology assessment of high temperature components in the improved (metal) and advanced (ceramic) Stirling engines was undertaken to evaluate the current state-of-the-art of metals and ceramics, identify materials research and development required to support the development of automotive Stirling engines, and to recommend materials technology programs to assure material readiness concurrent with engine system development programs. The most critical component for each engine is identified and some of the material problem areas are discussed.

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.

Energy efficient engine: Turbine intermediate case and low-pressure turbine component test hardware detailed design report

NASA Technical Reports Server (NTRS)

Leach, K.; Thulin, R. D.; Howe, D. C.

1982-01-01

A four stage, low pressure turbine component has been designed to power the fan and low pressure compressor system in the Energy Efficient Engine. Designs for a turbine intermediate case and an exit guide vane assembly also have been established. The components incorporate numerous technology features to enhance efficiency, durability, and performance retention. These designs reflect a positive step towards improving engine fuel efficiency on a component level. The aerodynamic and thermal/mechanical designs of the intermediate case and low pressure turbine components are presented and described. An overview of the predicted performance of the various component designs is given.

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1992-01-01

ATTAP activities during the past year included test-bed engine design and development, ceramic component design, materials and component characterization, ceramic component process development and fabrication, ceramic component rig testing, and test-bed engine fabrication and testing. Significant technical challenges remain, but all areas exhibited progress. Test-bed engine design and development included engine mechanical design, combustion system design, alternate aerodynamic designs of gasifier scrolls, and engine system integration aimed at upgrading the AGT-5 from a 1038 C (1900 F) metal engine to a durable 1372 C (2500 F) structural ceramic component test-bed engine. ATTAP-defined ceramic and associated ceramic/metal component design activities completed include the ceramic gasifier turbine static structure, the ceramic gasifier turbine rotor, ceramic combustors, the ceramic regenerator disk, the ceramic power turbine rotors, and the ceramic/metal power turbine static structure. The material and component characterization efforts included the testing and evaluation of seven candidate materials and three development components. Ceramic component process development and fabrication proceeded for the gasifier turbine rotor, gasifier turbine scroll, gasifier turbine vanes and vane platform, extruded regenerator disks, and thermal insulation. Component rig activities included the development of both rigs and the necessary test procedures, and conduct of rig testing of the ceramic components and assemblies. Test-bed engine fabrication, testing, and development supported improvements in ceramic component technology that permit the achievement of both program performance and durability goals. Total test time in 1991 amounted to 847 hours, of which 128 hours were engine testing, and 719 were hot rig testing.

Materials and structural aspects of advanced gas-turbine helicopter engines

NASA Technical Reports Server (NTRS)

Freche, J. C.; Acurio, J.

1979-01-01

The key to improved helicopter gas turbine engine performance lies in the development of advanced materials and advanced structural and design concepts. The modification of the low temperature components of helicopter engines (such as the inlet particle separator), the introduction of composites for use in the engine front frame, the development of advanced materials with increased use-temperature capability for the engine hot section, can result in improved performance and/or decreased engine maintenance cost. A major emphasis in helicopter engine design is the ability to design to meet a required lifetime. This, in turn, requires that the interrelated aspects of higher operating temperatures and pressures, cooling concepts, and environmental protection schemes be integrated into component design. The major material advances, coatings, and design life-prediction techniques pertinent to helicopter engines are reviewed; the current state-of-the-art is identified; and when appropriate, progress, problems, and future directions are assessed.

CF6 Jet Engine Performance Improvement Program: High Pressure Turbine Aerodynamic Performance Improvement

NASA Technical Reports Server (NTRS)

Fasching, W. A.

1980-01-01

The improved single shank high pressure turbine design was evaluated in component tests consisting of performance, heat transfer and mechanical tests, and in core engine tests. The instrumented core engine test verified the thermal, mechanical, and aeromechanical characteristics of the improved turbine design. An endurance test subjected the improved single shank turbine to 1000 simulated flight cycles, the equivalent of approximately 3000 hours of typical airline service. Initial back-to-back engine tests demonstrated an improvement in cruise sfc of 1.3% and a reduction in exhaust gas temperature of 10 C. An additional improvement of 0.3% in cruise sfc and 6 C in EGT is projected for long service engines.

Progress toward an advanced condition monitoring system for reusable rocket engines

NASA Technical Reports Server (NTRS)

Maram, J.; Barkhoudarian, S.

1987-01-01

A new generation of advanced sensor technologies will allow the direct measurement of critical/degradable rocket engine components' health and the detection of degraded conditions before component deterioration affects engine performance, leading to substantial improvements in reusable engines' operation and maintenance. When combined with a computer-based engine condition-monitoring system, these sensors can furnish a continuously updated data base for the prediction of engine availability and advanced warning of emergent maintenance requirements. Attention is given to the case of a practical turbopump and combustion device diagnostic/prognostic health-monitoring system.

Ceramic Matrix Composites for Rotorcraft Engines

NASA Technical Reports Server (NTRS)

Halbig, Michael C.

2011-01-01

Ceramic matrix composite (CMC) components are being developed for turbine engine applications. Compared to metallic components, the CMC components offer benefits of higher temperature capability and less cooling requirements which correlates to improved efficiency and reduced emissions. This presentation discusses a technology develop effort for overcoming challenges in fabricating a CMC vane for the high pressure turbine. The areas of technology development include small component fabrication, ceramic joining and integration, material and component testing and characterization, and design and analysis of concept components.

Energy Efficient Engine: Control system component performance report

NASA Technical Reports Server (NTRS)

Beitler, R. S.; Bennett, G. W.

1984-01-01

An Energy Efficient Engine (E3) program was established to develop technology for improving the energy efficiency of future commercial transport aircraft engines. As part of this program, General Electric designed and tested a new engine. The design, fabrication, bench and engine testing of the Full Authority Digital Electronic Control (FADEC) system used for controlling the E3 Demonstrator Engine is described. The system design was based on many of the proven concepts and component designs used on the General Electric family of engines. One significant difference is the use of the FADEC in place of hydromechanical computation currently used.

An engineering approach for the application of textile composites to a structural component

NASA Technical Reports Server (NTRS)

Baldwin, Jack W.; Gracias, Brian K.; Clark, Steven R.

1993-01-01

An engineering approach for the application of textile composites to a structural component is addressed. The main objective is to improve impact resistance of composite blades by using some form of 3-D reinforcement. Project goals, results, and conclusions are discussed.

An Object-Oriented Computer Code for Aircraft Engine Weight Estimation

NASA Technical Reports Server (NTRS)

Tong, Michael T.; Naylor, Bret A.

2009-01-01

Reliable engine-weight estimation at the conceptual design stage is critical to the development of new aircraft engines. It helps to identify the best engine concept amongst several candidates. At NASA Glenn Research Center (GRC), the Weight Analysis of Turbine Engines (WATE) computer code, originally developed by Boeing Aircraft, has been used to estimate the engine weight of various conceptual engine designs. The code, written in FORTRAN, was originally developed for NASA in 1979. Since then, substantial improvements have been made to the code to improve the weight calculations for most of the engine components. Most recently, to improve the maintainability and extensibility of WATE, the FORTRAN code has been converted into an object-oriented version. The conversion was done within the NASA's NPSS (Numerical Propulsion System Simulation) framework. This enables WATE to interact seamlessly with the thermodynamic cycle model which provides component flow data such as airflows, temperatures, and pressures, etc., that are required for sizing the components and weight calculations. The tighter integration between the NPSS and WATE would greatly enhance system-level analysis and optimization capabilities. It also would facilitate the enhancement of the WATE code for next-generation aircraft and space propulsion systems. In this paper, the architecture of the object-oriented WATE code (or WATE++) is described. Both the FORTRAN and object-oriented versions of the code are employed to compute the dimensions and weight of a 300-passenger aircraft engine (GE90 class). Both versions of the code produce essentially identical results as should be the case.

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.

Reusable rocket engine turbopump condition monitoring

NASA Technical Reports Server (NTRS)

Hampson, M. E.; Barkhoudarian, S.

1985-01-01

Significant improvements in engine readiness with attendant reductions in maintenance costs and turnaround times can be achieved with an engine condition monitoring system (CMS). The CMS provides real time health status of critical engine components, without disassembly, through component monitoring with advanced sensor technologies. Three technologies were selected to monitor the rotor bearings and turbine blades: the isotope wear detector and fiber optic deflectometer (bearings), and the fiber optic pyrometer (blades). Signal processing algorithms were evaluated and ranked for their utility in providing useful component health data to unskilled maintenance personnel. Design modifications to current configuration Space Shuttle Main Engine (SSME) high pressure turbopumps and the MK48-F turbopump were developed to incorporate the sensors.

Small Engine Component Technology (SECT) studies

NASA Technical Reports Server (NTRS)

Meyer, P. K.; Harbour, L.

1986-01-01

A study was conducted to identify component technology requirements for small, expendable gas turbine engines that would result in substantial improvements in performance and cost by the year 2000. A subsonic, 2600 nautical mile (4815 km) strategic cruise missile mission was selected for study. A baseline (state-of-the-art) engine and missile configuration were defined to evaluate the advanced technology engines. Two advanced technology engines were configured and evaluated using advanced component efficiencies and ceramic composite materials; a 22:1 overall pressure ratio, 3.85 bypass ratio twin-spool turbofan; and an 8:1 overall pressure, 3.66 bypass ratio, single-spool recuperated turbofan with 0.85 recuperator effectiveness. Results of mission analysis indicated a reduction in fuel burn of 38 and 47 percent compared to the baseline engine when using the advanced turbofan and recuperated turbofan, respectively. While use of either advanced engine resulted in approximately a 25 percent reduction in missile size, the unit life cycle (LCC) cost reduction of 56 percent for the advanced turbofan relative to the baseline engine gave it a decisive advantage over the recuperated turbofan with 47 percent LCC reduction. An additional range improvement of 10 percent results when using a 56 percent loaded carbon slurry fuel with either engine. These results can be realized only if significant progress is attained in the fields of solid lubricated bearings, small aerodynamic component performance, composite ceramic materials and integration of slurry fuels. A technology plan outlining prospective programs in these fields is presented.

Design study of a kinematic Stirling engine for dispered solar electric power systems

NASA Technical Reports Server (NTRS)

1980-01-01

The concept evaluation shows that the four cylinder double acting U type Stirling engine with annular regenerators is the most suitable engine type for the 15 kW solar application with respect to design, performance and cost. Results show that near term performance for a metallic Stirling engine is 42% efficiency. Further improved components show an impact on efficiency of the future metallic engine to 45%. Increase of heater temperature, through the introduction of ceramic components, contribute the greatest amount to achieve high efficiency goals. Future ceramic Stirling engines for solar applications show an efficiency of around 50%.

Improving safety of aircraft engines: a consortium approach

NASA Astrophysics Data System (ADS)

Brasche, Lisa J. H.

1996-11-01

With over seven million departures per year, air transportation has become not a luxury, but a standard mode of transportation for the United States. A critical aspect of modern air transport is the jet engine, a complex engineered component that has enabled the rapid travel to which we have all become accustomed. One of the enabling technologies for safe air travel is nondestructive evaluation, or NDE, which includes various inspection techniques used to assess the health or integrity of a structure, component, or material. The Engine Titanium Consortium (ETC) was established in 1993 to respond to recommendations made by the Federal Aviation Administration (FAA) Titanium Rotating Components Review Team (TRCRT) for improvements in inspection of engine titanium. Several recent accomplishments of the ETC are detailed in this paper. The objective of the Engine Titanium Consortium is to provide the FAAand the manufacturers with reliable and costeffective new methods and/or improvements in mature methods for detecting cracks, inclusions, and imperfections in titanium. The consortium consists of a team of researchers from academia and industry-namely, Iowa State University, Allied Signal Propulsion Engines, General Electric Aircraft Engines, and Pratt & Whitney Engines-who work together to develop program priorities, organize a program plan, conduct the research, and implement the solutions. The true advantage of the consortium approach is that it brings together the research talents of academia and the engineering talents of industry to tackle a technology-base problem. In bringing industrial competitors together, the consortium ensures that the research results, which have safety implications and result from FAA funds, are shared and become part of the public domain.

An Object-oriented Computer Code for Aircraft Engine Weight Estimation

NASA Technical Reports Server (NTRS)

Tong, Michael T.; Naylor, Bret A.

2008-01-01

Reliable engine-weight estimation at the conceptual design stage is critical to the development of new aircraft engines. It helps to identify the best engine concept amongst several candidates. At NASA Glenn (GRC), the Weight Analysis of Turbine Engines (WATE) computer code, originally developed by Boeing Aircraft, has been used to estimate the engine weight of various conceptual engine designs. The code, written in FORTRAN, was originally developed for NASA in 1979. Since then, substantial improvements have been made to the code to improve the weight calculations for most of the engine components. Most recently, to improve the maintainability and extensibility of WATE, the FORTRAN code has been converted into an object-oriented version. The conversion was done within the NASA s NPSS (Numerical Propulsion System Simulation) framework. This enables WATE to interact seamlessly with the thermodynamic cycle model which provides component flow data such as airflows, temperatures, and pressures, etc. that are required for sizing the components and weight calculations. The tighter integration between the NPSS and WATE would greatly enhance system-level analysis and optimization capabilities. It also would facilitate the enhancement of the WATE code for next-generation aircraft and space propulsion systems. In this paper, the architecture of the object-oriented WATE code (or WATE++) is described. Both the FORTRAN and object-oriented versions of the code are employed to compute the dimensions and weight of a 300- passenger aircraft engine (GE90 class). Both versions of the code produce essentially identical results as should be the case. Keywords: NASA, aircraft engine, weight, object-oriented

The first of a series of high efficiency, high bmep, turbocharged two-stroke cycle diesel engines; the general motors EMD 645FB engine

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

Kotlin, J.J.; Dunteman, N.R.; Scott, D.I.

1983-01-01

The current Electro-Motive Division 645 Series turbocharged engines are the Model FB and EC. The FB engine combines the highest thermal efficiency with the highest specific output of any EMD engine to date. The FB Series incorporates 16:1 compression ratio with a fire ring piston and an improved turbocharger design. Engine components included in the FB engine provide very high output levels with exceptional reliability. This paper also describes the performance of the lower rated Model EC engine series which feature high thermal efficiency and utilize many engine components well proven in service and basic to the Model FB Series.

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1993-01-01

The Advanced Turbine Technologies Application Project (ATTAP) is in the fifth year of a multiyear development program to bring the automotive gas turbine engine to a state at which industry can make commercialization decisions. Activities during the past year included reference powertrain design updates, test-bed engine design and development, ceramic component design, materials and component characterization, ceramic component process development and fabrication, ceramic component rig testing, and test-bed engine fabrication and testing. Engine design and development included mechanical design, combustion system development, alternate aerodynamic flow testing, and controls development. Design activities included development of the ceramic gasifier turbine static structure, the ceramic gasifier rotor, and the ceramic power turbine rotor. Material characterization efforts included the testing and evaluation of five candidate high temperature ceramic materials. Ceramic component process development and fabrication, with the objective of approaching automotive volumes and costs, continued for the gasifier turbine rotor, gasifier turbine scroll, extruded regenerator disks, and thermal insulation. Engine and rig fabrication, testing, and development supported improvements in ceramic component technology. Total test time in 1992 amounted to 599 hours, of which 147 hours were engine testing and 452 were hot rig testing.

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.

Development of a statistically proven injection molding method for reaction bonded silicon nitride, sintering reaction bonded silicon nitride, and sintered silicon nitride

NASA Astrophysics Data System (ADS)

Steiner, Matthias

A statistically proven, series injection molding technique for ceramic components was developed for the construction of engines and gas turbines. The flow behavior of silicon injection-molding materials was characterized and improved. Hot-isostatic-pressing reaction bonded silicon nitride (HIPRBSN) was developed. A nondestructive component evaluation method was developed. An injection molding line for HIPRBSN engine components precombustion chamber, flame spreader, and valve guide was developed. This line allows the production of small series for engine tests.

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.

Evaluation of surface integrity of WEDM processed inconel 718 for jet engine application

NASA Astrophysics Data System (ADS)

Sharma, Priyaranjan; Tripathy, Ashis; Sahoo, Narayan

2018-03-01

A unique superalloy, Inconel 718 has been serving for aerospace industries since last two decades. Due to its attractive properties such as high strength at elevated temperature, improved corrosion and oxidation resistance, it is widely employed in the manufacturing of jet engine components. These components require complex shape without affecting the parent material properties. Traditional machining methods seem to be ineffective to fulfil the demand of aircraft industries. Therefore, an advanced feature of wire electrical discharge machining (WEDM) has been utilized to improve the surface features of the jet engine components. With the help of trim-offset technology, it became possible to achieve considerable amount of residual stresses, lower peak to valley height, reduced density of craters and micro globules, minimum hardness alteration and negligible recast layer formation.

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.

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.

Turbine Engine Clearance Control Systems: Current Practices and Future Directions

NASA Astrophysics Data System (ADS)

Lattime, Scott B.; Steinetz, Bruce M.

2002-09-01

Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed 1M. Engine removal from service is primarily due to spent exhaust gas temperature (EGT) margin caused mainly by the deterioration of HPT components. Increased blade tip clearance is a major factor in hot section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero gas turbine engine HPT performance degradation and the mechanisms that promote these losses are discussed. Benefits to the HPT due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next generation engine clearance control systems.

Turbine Engine Clearance Control Systems: Current Practices and Future Directions

NASA Technical Reports Server (NTRS)

Lattime, Scott B.; Steinetz, Bruce M.

2002-01-01

Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed $1M. Engine removal from service is primarily due to spent exhaust gas temperature (EGT) margin caused mainly by the deterioration of HPT components. Increased blade tip clearance is a major factor in hot section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero gas turbine engine HPT performance degradation and the mechanisms that promote these losses are discussed. Benefits to the HPT due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next generation engine clearance control systems.

Energy efficient engine component development and integration program

NASA Technical Reports Server (NTRS)

1982-01-01

The objective of the Energy Efficient Engine Component Development and Integration program is to develop, evaluate, and demonstrate the technology for achieving lower installed fuel consumption and lower operating costs in future commercial turbofan engines. Minimum goals have been set for a 12 percent reduction in thrust specific fuel consumption (TSFC), 5 percent reduction in direct operating cost (DOC), and 50 percent reduction in performance degradation for the Energy Efficient Engine (flight propulsion system) relative to the JT9D-7A reference engine. The Energy Efficienct Engine features a twin spool, direct drive, mixed flow exhaust configuration, utilizing an integrated engine nacelle structure. A short, stiff, high rotor and a single stage high pressure turbine are among the major enhancements in providing for both performance retention and major reductions in maintenance and direct operating costs. Improved clearance control in the high pressure compressor and turbines, and advanced single crystal materials in turbine blades and vanes are among the major features providing performance improvement. Highlights of work accomplished and programs modifications and deletions are presented.

An Engineering Student's Guide to the Humanities & Social Sciences.

ERIC Educational Resources Information Center

Association of American Colleges, Washington, DC.

Undergraduate engineering students and their advisors are provided with a handbook to help improve the quality and coherence of the humanities and social sciences (H&SS) component of undergraduate engineering education (fostering more purposeful H&SS course selection). The first of this handbook's three sections has an engineering major…

Exergy as a useful tool for the performance assessment of aircraft gas turbine engines: A key review

NASA Astrophysics Data System (ADS)

Şöhret, Yasin; Ekici, Selcuk; Altuntaş, Önder; Hepbasli, Arif; Karakoç, T. Hikmet

2016-05-01

It is known that aircraft gas turbine engines operate according to thermodynamic principles. Exergy is considered a very useful tool for assessing machines working on the basis of thermodynamics. In the current study, exergy-based assessment methodologies are initially explained in detail. A literature overview is then presented. According to the literature overview, turbofans may be described as the most investigated type of aircraft gas turbine engines. The combustion chamber is found to be the most irreversible component, and the gas turbine component needs less exergetic improvement compared to all other components of an aircraft gas turbine engine. Finally, the need for analyses of exergy, exergo-economic, exergo-environmental and exergo-sustainability for aircraft gas turbine engines is emphasized. A lack of agreement on exergy analysis paradigms and assumptions is noted by the authors. Exergy analyses of aircraft gas turbine engines, fed with conventional fuel as well as alternative fuel using advanced exergy analysis methodology to understand the interaction among components, are suggested to those interested in thermal engineering, aerospace engineering and environmental sciences.

The Development of Environmental Barrier Coatings for SiCSiC Ceramic Matrix Composites: Challenges and Opportunities

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2014-01-01

Environmental barrier coatings (EBCs) and SiC/SiC ceramic matrix composites (CMCs) systems will play a crucial role in future turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is a key to enable the applications of the envisioned CMC components to help achieve next generation engine performance and durability goals. This paper will primarily address the performance requirements and design considerations of environmental barrier coatings for turbine engine applications. The emphasis is placed on current candidate environmental barrier coating systems for SiCSiC CMCs, their performance benefits and design limitations in long-term operation and combustion environments. Major technical barriers in developing advanced environmental barrier coating systems, the coating integrations with next generation CMC turbine components having improved environmental stability, cyclic durability and system performance will be described. The development trends for turbine environmental barrier coating systems by utilizing improved compositions, state-of-the-art processing methods, and simulated environment testing and durability modeling will be discussed.

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1990-01-01

Advanced Turbine Technology Application Project (ATTAP) activities during the past year were highlighted by test-bed engine design and development activities; ceramic component design; materials and component characterization; ceramic component process development and fabrication; component rig testing; and test-bed engine fabrication and testing. Although substantial technical challenges remain, all areas exhibited progress. Test-bed engine design and development activity included engine mechanical design, power turbine flow-path design and mechanical layout, and engine system integration aimed at upgrading the AGT-5 from a 1038 C metal engine to a durable 1371 C structural ceramic component test-bed engine. ATTAP-defined ceramic and associated ceramic/metal component design activities include: the ceramic combustor body, the ceramic gasifier turbine static structure, the ceramic gasifier turbine rotor, the ceramic/metal power turbine static structure, and the ceramic power turbine rotors. The materials and component characterization efforts 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 are being conducted for the gasifier turbine rotor, gasifier turbine vanes, gasifier turbine scroll, extruded regenerator disks, and thermal insulation. Component rig testing activities include the development of the necessary test procedures and conduction of rig testing of the ceramic components and assemblies. Four-hundred hours of hot gasifier rig test time were accumulated with turbine inlet temperatures exceeding 1204 C at 100 percent design gasifier speed. A total of 348.6 test hours were achieved on a single ceramic rotor without failure and a second ceramic rotor was retired in engine-ready condition at 364.9 test hours. Test-bed engine fabrication, testing, and development supported improvements in ceramic component technology that will permit the achievement of program performance and durability goals. The designated durability engine accumulated 359.3 hour of test time, 226.9 of which were on the General Motors gas turbine durability schedule.

Durability and CMAS Resistance of Advanced Environmental Barrier Coatings Systems for SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2015-01-01

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. This paper will emphasize advanced environmental barrier coating developments for SiCSiC turbine airfoil components, by using advanced coating compositions and processing, in conjunction with mechanical and environment testing and durability validations. The coating-CMC degradations and durability in the laboratory simulated engine fatigue-creep and complex operating environments are being addressed. The effects of Calcium-Magnesium-Alumino-Silicate (CMAS) from road sand or volcano-ash deposits on the degradation mechanisms of the environmental barrier coating systems will be discussed. The results help understand the advanced EBC-CMC system performance, aiming at the durability improvements of more robust, prime-reliant environmental barrier coatings for successful applications of the component technologies and lifing methodologies.

Fuel conservative aircraft engine technology

NASA Technical Reports Server (NTRS)

Nored, D. L.

1978-01-01

Technology developments for more fuel-efficiency subsonic transport aircraft are reported. Three major propulsion projects were considered: (1) engine component improvement - directed at current engines; (2) energy efficient engine - directed at new turbofan engines; and (3) advanced turboprops - directed at technology for advanced turboprop-powered aircraft. Each project is reviewed and some of the technologies and recent accomplishments are described.

The CF6 engine performance improvement

NASA Technical Reports Server (NTRS)

Fasching, W. A.

1982-01-01

As part of the NASA-sponsored Engine Component Improvement (ECI) Program, a feasibility analysis of performance improvement and retention concepts for the CF6-6 and CF6-50 engines was conducted and seven concepts were identified for development and ground testing: new fan, new front mount, high pressure turbine aerodynamic performance improvement, high pressure turbine roundness, high pressure turbine active clearance control, low pressure turbine active clearance control, and short core exhaust nozzle. The development work and ground testing are summarized, and the major test results and an enomic analysis for each concept are presented.

Space Shuttle Project

NASA Image and Video Library

1996-12-16

A NASA scientist displays Space Shuttle Main Engine (SSME) turbine component which underwent air flow tests at Marshall's Structures and Dynamics Lab. Such studies could improve efficiency of aircraft engines, and lower operational costs.

A Modular Aerospike Engine Design Using Additive Manufacturing

NASA Technical Reports Server (NTRS)

Peugeot, John; Garcia, Chance; Burkhardt, Wendel

2014-01-01

A modular aerospike engine concept has been developed with the objective of demonstrating the viability of the aerospike design using additive manufacturing techniques. The aerospike system is a self-compensating design that allows for optimal performance over the entire flight regime and allows for the lowest possible mass vehicle designs. At low altitudes, improvements in Isp can be traded against chamber pressure, staging, and payload. In upper stage applications, expansion ratio and engine envelope can be traded against nozzle efficiency. These features provide flexibility to the System Designer optimizing a complete vehicle stage. The aerospike concept is a good example of a component that has demonstrated improved performance capability, but traditionally has manufacturing requirements that are too expensive and complex to use in a production vehicle. In recent years, additive manufacturing has emerged as a potential method for improving the speed and cost of building geometrically complex components in rocket engines. It offers a reduction in tooling overhead and significant improvements in the integration of the designer and manufacturing method. In addition, the modularity of the engine design provides the ability to perform full scale testing on the combustion devices outside of the full engine configuration. The proposed design uses a hydrocarbon based gas-generator cycle, with plans to take advantage of existing powerhead hardware while focusing DDT&E resources on manufacturing and sub-system testing of the combustion devices. The major risks for the modular aerospike concept lie in the performance of the propellant feed system, the structural integrity of the additive manufactured components, and the aerodynamic efficiency of the exhaust flow.

Development and Property Evaluation of Selected HfO2-Silicon and Rare Earth-Silicon Based Bond Coats and Environmental Barrier Coating Systems for SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2016-01-01

Ceramic environmental barrier coatings (EBC) and SiC/SiC 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 SiC/SiC 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 and rare earth Si based EBC bond coat EBC systems for SiC/SiC CMC combustor and turbine airfoil applications are investigated. High temperature properties of the advanced EBC systems, including the strength, fracture toughness, creep and oxidation resistance have been studied and summarized. The advanced NASA EBC systems showed some promise to achieve 1500C temperature capability, helping enable next generation turbine engines with significantly improved engine component temperature capability and durability.

Energy efficient engine component development and integration program

NASA Technical Reports Server (NTRS)

1982-01-01

The development of the technology to improve energy efficiency of propulsion systems for subsonic commercial aircrafts was examined. Goals established include: (1) fuel consumption, reduction in flight propulsion system; (2) direct operation cost; (3) noise, with provision for engine growth corresponding to future engine application; and (4) emissions, EPA new engine standards.

Application of advanced coating techniques to rocket engine components

NASA Technical Reports Server (NTRS)

Verma, S. K.

1988-01-01

The materials problem in the space shuttle main engine (SSME) is reviewed. Potential coatings and the method of their application for improved life of SSME components are discussed. A number of advanced coatings for turbine blade components and disks are being developed and tested in a multispecimen thermal fatigue fluidized bed facility at IIT Research Institute. This facility is capable of producing severe strains of the degree present in blades and disk components of the SSME. The potential coating systems and current efforts at IITRI being taken for life extension of the SSME components are summarized.

Overview of a stirling engine test project

NASA Technical Reports Server (NTRS)

Slaby, J. G.

1980-01-01

Tests were conducted on three Stirling engines ranging in size from 1.33 to 53 horsepower (1 to 40 kW). The tests were directed toward developing alternative, backup component concepts to improve engine efficiency and performance or to reduce costs. Some of the activities included investigating attractive concepts and materials for cooler-regenerator units, installing a jet impingement device on a Stirling engine to determine its potential for improved engine performance, and presenting performance maps for initial characterization of Stirling engines. The experiment results of the tests are presented along with predictions of results of future tests to be conducted on the Stirling engines.

Orbit Transfer Rocket Engine Technology Program: Advanced engine study, task D.1/D.3

NASA Technical Reports Server (NTRS)

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

1986-01-01

Concepts for space maintainability of OTV engines were examined. An engine design was developed which was driven by space maintenance requirements and by a failure mode and effects (FME) analysis. Modularity within the engine was shown to offer cost benefits and improved space maintenance capabilities. Space operable disconnects were conceptualized for both engine change-out and for module replacement. Through FME mitigation the modules were conceptualized to contain the least reliable and most often replaced engine components. A preliminary space maintenance plan was developed around a controls and condition monitoring system using advanced sensors, controls, and condition monitoring concepts. A complete engine layout was prepared satisfying current vehicle requirements and utilizing projected component advanced technologies. A technology plan for developing the required technology was assembled.

CF6 jet engine performance improvement: New fan

NASA Technical Reports Server (NTRS)

Fasching, W. A.

1980-01-01

As part of the NASA sponsored engine component improvement program, and fan package was developed to reduce fuel consumption in current CF6 turbofan aircraft engine. The new fan package consist of an improved fan blade, reduced fan tip clearance due to a fan case stiffener, and a smooth fan casing tip shroud. CF6 engine performance and acoustic tests demonstrated the predicted 1.8% improvement in cruise sfc without an increase in engine noise. Power management thrust/fan speed characteristics were defined. Mechanical and structural integrity was demonstrated in model fan rotor photoelastic stress tests, full-size fan blade bench fatigue tests, and CF6 engine bird ingestion, crosswind, and cyclic endurance tests. The fan was certified in the CF6-500c2/E2 engines and is in commerical service on the Boeing 747-200, Douglas DC-10-30, and Atrbus industrie A300B aircraft.

CF6 Jet Engine Performance Improvement: High Pressure Turbine Active Clearance Control

NASA Technical Reports Server (NTRS)

Rich, S. E.; Fasching, W. A.

1982-01-01

An active clearance control system was developed which reduces fuel consumption and performance degradation. This system utilizes compressor discharge air during takeoff and fan discharge air during cruise to impinge on the shroud structure to improve the thermal response. The system was evaluated in component and engine tests. The test results demonstrated a performance improvement of 0.7 percent in cruise SFC.

Changing the Conversation: Messages for Improving Public Understanding of Engineering

ERIC Educational Resources Information Center

National Academies Press, 2008

2008-01-01

Can the United States continue to lead the world in innovation? The answer may hinge in part on how well the public understands engineering, a key component of the "innovation engine." A related concern is how to encourage young people--particularly girls and under-represented minorities--to consider engineering as a career option.…

Tags Extarction from Spatial Documents in Search Engines

NASA Astrophysics Data System (ADS)

Borhaninejad, S.; Hakimpour, F.; Hamzei, E.

2015-12-01

Nowadays the selective access to information on the Web is provided by search engines, but in the cases which the data includes spatial information the search task becomes more complex and search engines require special capabilities. The purpose of this study is to extract the information which lies in spatial documents. To that end, we implement and evaluate information extraction from GML documents and a retrieval method in an integrated approach. Our proposed system consists of three components: crawler, database and user interface. In crawler component, GML documents are discovered and their text is parsed for information extraction; storage. The database component is responsible for indexing of information which is collected by crawlers. Finally the user interface component provides the interaction between system and user. We have implemented this system as a pilot system on an Application Server as a simulation of Web. Our system as a spatial search engine provided searching capability throughout the GML documents and thus an important step to improve the efficiency of search engines has been taken.

Engine design considerations for 2nd generation supersonic transports

NASA Technical Reports Server (NTRS)

Howlett, R. A.

1975-01-01

The environmental and economic goals projected for advanced supersonic transports will require revolutionary improvements in propulsion systems. Variable cycle engine concepts that incorporate unique components and advanced technologies show promise in meeting these goals. Pratt & Whitney Aircraft is conducting conceptual design studies of variable cycle engine concepts under NASA sponsorship. This paper reviews some of the design considerations for these engine concepts. Emphasis is placed on jet noise abatement, reduction of emissions, performance improvements, installation considerations, hot-section characteristics and control system requirements. Two representative variable cycle engine concepts that incorporate these basic design considerations are described.

Quiet Clean Short-haul Experimental Engine (QCSEE) under-the-wing engine digital control system design report

NASA Technical Reports Server (NTRS)

1978-01-01

A digital electronic control was combined with conventional hydromechanical components to operate the four controlled variables on the under-the-wing engine: fuel flow, fan blade pitch, fan exhaust area, and core compressor stator angles. The engine and control combination offers improvements in noise, pollution, thrust response, operational monitoring, and pilot workload relative to current engines.

Ceramic thermal barrier coatings for commercial gas turbine engines

NASA Technical Reports Server (NTRS)

Meier, Susan Manning; Gupta, Dinesh K.; Sheffler, Keith D.

1991-01-01

The paper provides an overview of the short history, current status, and future prospects of ceramic thermal barrier coatings for gas turbine engines. Particular attention is given to plasma-sprayed and electron beam-physical vapor deposited yttria-stabilized (7 wt pct Y2O3) zirconia systems. Recent advances include improvements in the spallation life of thermal barrier coatings, improved bond coat composition and spraying techniques, and improved component design. The discussion also covers field experience, life prediction modeling, and future directions in ceramic coatings in relation to gas turbine engine design.

Anti-air pollution & energy conservation system for automobiles using leaded or unleaded gasoline, diesel or alternate fuel

DOEpatents

Bose, Ranendra K.

2002-06-04

Exhaust gases from an internal combustion engine operating with leaded or unleaded gasoline or diesel or natural gas, are used for energizing a high-speed gas turbine. The convoluting gas discharge causes a first separation stage by stratifying of heavier and lighter exhaust gas components that exit from the turbine in opposite directions, the heavier components having a second stratifying separation in a vortex tube to separate combustible pollutants from non-combustible components. The non-combustible components exit a vortex tube open end to atmosphere. The lighter combustible, pollutants effected in the first separation are bubbled through a sodium hydroxide solution for dissolving the nitric oxide, formaldehyde impurities in this gas stream before being piped to the engine air intake for re-combustion, thereby reducing the engine's exhaust pollution and improving its fuel economy. The combustible, heavier pollutants from the second separation stage are piped to air filter assemblies. This gas stream convoluting at a high-speed through the top stator-vanes of the air filters, centrifugally separates the coalescent water, aldehydes, nitrogen dioxides, sulfates, sulfur, lead particles which collect at the bottom of the bowl, wherein it is periodically released to the roadway. Whereas, the heavier hydrocarbon, carbon particles are piped through the air filter's porous element to the engine air intake for re-combustion, further reducing the engine's exhaust pollution and improving its fuel economy.

Aircraft Energy Efficiency (ACEE) status report

NASA Technical Reports Server (NTRS)

Nored, D. L.; Dugan, J. F., Jr.; Saunders, N. T.; Ziemianski, J. A.

1979-01-01

Fuel efficiency in aeronautics, for fuel conservation in general as well as for its effect on commercial aircraft operating economics is considered. Projects of the Aircraft Energy Efficiency Program related to propulsion are emphasized. These include: (1) engine component improvement, directed at performance improvement and engine diagnostics for prolonged service life; (2) energy efficient engine, directed at proving the technology base for the next generation of turbofan engines; and (3) advanced turboprop, directed at advancing the technology of turboprop powered aircraft to a point suitable for commercial airline service. Progress in these technology areas is reported.

Introduction to tissue engineering and application for cartilage engineering.

PubMed

de Isla, N; Huseltein, C; Jessel, N; Pinzano, A; Decot, V; Magdalou, J; Bensoussan, D; Stoltz, J-F

2010-01-01

Tissue engineering is a multidisciplinary field that applies the principles of engineering, life sciences, cell and molecular biology toward the development of biological substitutes that restore, maintain, and improve tissue function. In Western Countries, tissues or cells management for clinical uses is a medical activity governed by different laws. Three general components are involved in tissue engineering: (1) reparative cells that can form a functional matrix; (2) an appropriate scaffold for transplantation and support; and (3) bioreactive molecules, such as cytokines and growth factors that will support and choreograph formation of the desired tissue. These three components may be used individually or in combination to regenerate organs or tissues. Thus the growing development of tissue engineering needs to solve four main problems: cells, engineering development, grafting and safety studies.

Vascularized Bone Tissue Engineering: Approaches for Potential Improvement

PubMed Central

Nguyen, Lonnissa H.; Annabi, Nasim; Nikkhah, Mehdi; Bae, Hojae; Binan, Loïc; Park, Sangwon; Kang, Yunqing

2012-01-01

Significant advances have been made in bone tissue engineering (TE) in the past decade. However, classical bone TE strategies have been hampered mainly due to the lack of vascularization within the engineered bone constructs, resulting in poor implant survival and integration. In an effort toward clinical success of engineered constructs, new TE concepts have arisen to develop bone substitutes that potentially mimic native bone tissue structure and function. Large tissue replacements have failed in the past due to the slow penetration of the host vasculature, leading to necrosis at the central region of the engineered tissues. For this reason, multiple microscale strategies have been developed to induce and incorporate vascular networks within engineered bone constructs before implantation in order to achieve successful integration with the host tissue. Previous attempts to engineer vascularized bone tissue only focused on the effect of a single component among the three main components of TE (scaffold, cells, or signaling cues) and have only achieved limited success. However, with efforts to improve the engineered bone tissue substitutes, bone TE approaches have become more complex by combining multiple strategies simultaneously. The driving force behind combining various TE strategies is to produce bone replacements that more closely recapitulate human physiology. Here, we review and discuss the limitations of current bone TE approaches and possible strategies to improve vascularization in bone tissue substitutes. PMID:22765012

7 CFR 1724.40 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

... ELECTRIC ENGINEERING, ARCHITECTURAL SERVICES AND DESIGN POLICIES AND PROCEDURES Electric System Planning... long-term needs for plant additions, improvements, replacements, and retirements for their electric systems. The primary components of the planning system consist of long-range engineering plans and...

Aeropropulsion 1979. [conferences

NASA Technical Reports Server (NTRS)

1979-01-01

State of the art technology in aeronautical propulsion is assessed. Noise and air pollution control techniques, advances in supersonic propulsion for transport aircraft, and composite materials and structures for reliable engine components are covered along with engine design for improved fuel consumption.

Current trends in water-in-diesel emulsion as a fuel.

PubMed

Yahaya Khan, Mohammed; Abdul Karim, Z A; Hagos, Ftwi Yohaness; Aziz, A Rashid A; Tan, Isa M

2014-01-01

Water-in-diesel emulsion (WiDE) is an alternative fuel for CI engines that can be employed with the existing engine setup with no additional engine retrofitting. It has benefits of simultaneous reduction of both NO x and particulate matters in addition to its impact in the combustion efficiency improvement, although this needs further investigation. This review paper addresses the type of emulsion, the microexplosion phenomenon, emulsion stability and physiochemical improvement, and effect of water content on the combustion and emissions of WiDE fuel. The review also covers the recent experimental methodologies used in the investigation of WiDE for both transport and stationary engine applications. In this review, the fuel injection pump and spray nozzle arrangement has been found to be the most critical components as far as the secondary atomization is concerned and further investigation of the effect of these components in the microexplosion of the emulsion is suggested to be center of focus.

Engineering Probiotics that Improve Warfighter Performance by Maintaining Lean Body Mass and Inhibiting Anxiety

DTIC Science & Technology

2017-10-03

and Microbiome Research Seminar Series . Baylor College of Medicine. 10/26/16. 12. "Rewiring the DNA binding domains ofbacterial two-component system...Structural and Quantitative Biology Seminar Series . 11/16/15. 16. "Engineering bacterial two component signal transduction systems to function as sensors...hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and

The Einstein Suite: A Web-Based Tool for Rapid and Collaborative Engineering Design and Analysis

NASA Technical Reports Server (NTRS)

Palmer, Richard S.

1997-01-01

Taken together the components of the Einstein Suite provide two revolutionary capabilities - they have the potential to change the way engineering and financial engineering are performed by: (1) providing currently unavailable functionality, and (2) providing a 10-100 times improvement over currently available but impractical or costly functionality.

Study and Test to Confirm Automobile Drivetrain Components to Improve Fuel Economy : Volume 1. History of the Automobile Transmission in the United States

DOT National Transportation Integrated Search

1979-05-01

Since the earliest days of the motor car, engineers have tinkered together various means of connecting the engine to the ground. While the wheel rapidly became the norm for the ground/vehicle interface, many different engine/wheel coupling techniques...

Collaborating for Success: Team Teaching the Engineering Technical Thesis

ERIC Educational Resources Information Center

Keating, Terrence; Long, Mike

2012-01-01

This paper will examine the collaborative teaching process undertaken at College of the North Atlantic-Qatar (CNA-Q) by Engineering and the Communication faculties to improve the overall quality of engineering students' capstone projects known as the Technical Thesis. The Technical Thesis is divided into two separate components: a proposal stage…

Revolutionary opportunities for materials and structures study

NASA Technical Reports Server (NTRS)

Schweiger, F. A.

1987-01-01

The revolutionary opportunities for materials and structures study was performed to provide Government and Industry focus for advanced materials technology. Both subsonic and supersonic engine studies and aircraft fuel burn and DOC evaluation are examined. Year 2010 goal materials were used in the advanced engine studies. These goal materials and improved component aero yielded subsonic fuel burn and DOC improvements of 13.4 percent and 5 percent, respectively and supersonic fuel burn and DOC improvements of 21.5 percent and 18 percent, respectively. Conclusions are that the supersonic study engine yielded fuel burn and DOC improvements well beyond the program goals; therefore, it is appropriate that advanced material programs be considered.

The NASA Aircraft Energy Efficiency program

NASA Technical Reports Server (NTRS)

Klineberg, J. M.

1979-01-01

A review is provided of the goals, objectives, and recent progress in each of six aircraft energy efficiency programs aimed at improved propulsive, aerodynamic and structural efficiency for future transport aircraft. Attention is given to engine component improvement, an energy efficient turbofan engine, advanced turboprops, revolutionary gains in aerodynamic efficiency for aircraft of the late 1990s, laminar flow control, and composite primary aircraft structures.

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.

Exergo-Economic Analysis of an Experimental Aircraft Turboprop Engine Under Low Torque Condition

NASA Astrophysics Data System (ADS)

Atilgan, Ramazan; Turan, Onder; Aydin, Hakan

Exergo-economic analysis is an unique combination of exergy analysis and cost analysis conducted at the component level. In exergo-economic analysis, cost of each exergy stream is determined. Inlet and outlet exergy streams of the each component are associated to a monetary cost. This is essential to detect cost-ineffective processes and identify technical options which could improve the cost effectiveness of the overall energy system. In this study, exergo-economic analysis is applied to an aircraft turboprop engine. Analysis is based on experimental values at low torque condition (240 N m). Main components of investigated turboprop engine are the compressor, the combustor, the gas generator turbine, the free power turbine and the exhaust. Cost balance equations have been formed for all components individually and exergo-economic parameters including cost rates and unit exergy costs have been calculated for each component.

Life prediction of turbine components: On-going studies at the NASA Lewis Research Center

NASA Technical Reports Server (NTRS)

Spera, D. A.; Grisaffe, S. J.

1973-01-01

An overview is presented of the many studies at NASA-Lewis that form the turbine component life prediction program. This program has three phases: (1) development of life prediction methods for major failure modes through materials studies, (2) evaluation and improvement of these methods through a variety of burner rig studies on simulated components in research engines and advanced rigs. These three phases form a cooperative, interdisciplinary program. A bibliography of Lewis publications on fatigue, oxidation and coatings, and turbine engine alloys is included.

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.

The Use of Probabilistic Methods to Evaluate the Systems Impact of Component Design Improvements on Large Turbofan Engines

NASA Technical Reports Server (NTRS)

Packard, Michael H.

2002-01-01

Probabilistic Structural Analysis (PSA) is now commonly used for predicting the distribution of time/cycles to failure of turbine blades and other engine components. These distributions are typically based on fatigue/fracture and creep failure modes of these components. Additionally, reliability analysis is used for taking test data related to particular failure modes and calculating failure rate distributions of electronic and electromechanical components. How can these individual failure time distributions of structural, electronic and electromechanical component failure modes be effectively combined into a top level model for overall system evaluation of component upgrades, changes in maintenance intervals, or line replaceable unit (LRU) redesign? This paper shows an example of how various probabilistic failure predictions for turbine engine components can be evaluated and combined to show their effect on overall engine performance. A generic model of a turbofan engine was modeled using various Probabilistic Risk Assessment (PRA) tools (Quantitative Risk Assessment Software (QRAS) etc.). Hypothetical PSA results for a number of structural components along with mitigation factors that would restrict the failure mode from propagating to a Loss of Mission (LOM) failure were used in the models. The output of this program includes an overall failure distribution for LOM of the system. The rank and contribution to the overall Mission Success (MS) is also given for each failure mode and each subsystem. This application methodology demonstrates the effectiveness of PRA for assessing the performance of large turbine engines. Additionally, the effects of system changes and upgrades, the application of different maintenance intervals, inclusion of new sensor detection of faults and other upgrades were evaluated in determining overall turbine engine reliability.

Development of coin-type cell and engineering of its compartments for rechargeable seawater batteries

NASA Astrophysics Data System (ADS)

Han, Jinhyup; Hwang, Soo Min; Go, Wooseok; Senthilkumar, S. T.; Jeon, Donghoon; Kim, Youngsik

2018-01-01

Cell design and optimization of the components, including active materials and passive components, play an important role in constructing robust, high-performance rechargeable batteries. Seawater batteries, which utilize earth-abundant and natural seawater as the active material in an open-structured cathode, require a new platform for building and testing the cells other than typical Li-ion coin-type or pouch-type cells. Herein, we present new findings based on our optimized cell. Engineering the cathode components-improving the wettability of cathode current collector and seawater catholyte flow-improves the battery performance (voltage efficiency). Optimizing the cell component and design is the key to identifying the electrochemical processes and reactions of active materials. Hence, the outcome of this research can provide a systematic study of potentially active materials used in seawater batteries and their effectiveness on the electrochemical performance.

Lifing of Engine Components

NASA Technical Reports Server (NTRS)

2005-01-01

The successful development of advanced aerospace engines depends greatly on the capabilities of high performance materials and structures. Advanced materials, such as nickel based single crystal alloys, metal foam, advanced copper alloys, and ceramics matrix composites, have been engineered to provide higher engine temperature and stress capabilities. Thermal barrier coatings have been developed to improve component durability and fuel efficiency, by reducing the substrate hot wall metal temperature and protecting against oxidation and blanching. However, these coatings are prone to oxidation and delamination failures. In order to implement the use of these materials in advanced engines, it is necessary to understand and model the evolution of damage of the metal substrate as well as the coating under actual engine conditions. The models and the understanding of material behavior are utilized in the development of a life prediction methodology for hot section components. The research activities were focused on determining the stress and strain fields in an engine environment under combined thermo-mechanical loads to develop life prediction methodologies consistent with the observed damage formation of the coating and the substrates.

Space Shuttle main engine product improvement

NASA Technical Reports Server (NTRS)

Lucci, A. D.; Klatt, F. P.

1985-01-01

The current design of the Space Shuttle Main Engine has passed 11 certification cycles, amassed approximately a quarter million seconds of engine test time in 1200 tests and successfully launched the Space Shuttle 17 times of 51 engine launches through May 1985. Building on this extensive background, two development programs are underway at Rocketdyne to improve the flow of hot gas through the powerhead and evaluate the changes to increase the performance margins in the engine. These two programs, called Phase II+ and Technology Test Bed Precursor program are described. Phase II+ develops a two-tube hot-gas manifold that improves the component environment. The Precursor program will evaluate a larger throat main combustion chamber, conduct combustion stability testing of a baffleless main injector, fabricate an experimental weld-free heat exchanger tube, fabricate and test a high pressure oxidizer turbopump with an improved inlet, and develop and test methods for reducing temperature transients at start and shutdown.

Fluid design studies of integrated modular engine system

NASA Technical Reports Server (NTRS)

Frankenfield, Bruce; Carek, Jerry

1993-01-01

A study was performed to develop a fluid system design and show the feasibility of constructing an integrated modular engine (IME) configuration, using an expander cycle engine. The primary design goal of the IME configuration was to improve the propulsion system reliability. The IME fluid system was designed as a single fault tolerant system, while minimizing the required fluid components. This study addresses the design of the high pressure manifolds, turbopumps and thrust chambers for the IME configuration. A physical layout drawing was made, which located each of the fluid system components, manifolds and thrust chambers. Finally, a comparison was made between the fluid system designs of an IME system and a non-network (clustered) engine system.

Building an Ecosystem for a New Engineering Program

NASA Astrophysics Data System (ADS)

Grebski, Wieslaw; Grebski, Michalene Eva

2018-06-01

Penn State Hazleton has recently developed and implemented a new Engineering program with a focus on energy efficiency and energy sustainability. To accelerate the implementation cycle of the program, it was necessary to very rapidly create and establish the components of an ecosystem needed for the Engineering program to prosper and grow. This paper describes the individual components of the ecosystem as well as the methods used to establish them. The paper also discusses the different initiatives to increase enrollment as well as placement rates for graduates. Continuous quality improvement procedure applied to maintain the quality of the program is also being discussed.

Vehicle Systems Engineering and Integration Activities

DTIC Science & Technology

2012-08-31

of the Assistant Secretary of Defense for Research and Engineering. Its objective is to fundamentally change the capabilities for the design...Reliability Improvements for Selected Equipment) package. The standard RISE package includes an upgraded propulsion system ( turbocharged engine and...component of the RISE powertrain incorporated into the original M113A3 and M730A2 vehicles is the turbocharged 275 hp 6V53T engine from Detroit Diesel

Allison V–1710 Engine on a Dynamotor Stand in the Engine Research Building

NASA Image and Video Library

1943-03-21

The first research assignment specifically created for the National Advisory Committee for Aeronautics’ (NACA) new Aircraft Engine Research Laboratory was the integration of a supercharger into the Allison V–1710 engine. The military was relying on the liquid-cooled V–1710 to power several types of World War II fighter aircraft and wanted to improve the engine's speed and altitude performance. Superchargers forced additional airflow into the combustion chamber, which increased the engine’s performance resulting in greater altitudes and speeds. They also generated excess heat that affected the engine cylinders, oil, and fuel. In 1943 the military tasked the new Aircraft Engine Research Laboratory to integrate the supercharger, improve the cooling system, and remedy associated engine knock. Three Allison engines were provided to the laboratory’s research divisions. One group was tasked with improving the supercharger performance, another analyzed the effect of the increased heat on knock in the fuel, one was responsible for improving the cooling system, and another would install the new components on the engine with minimal drag penalties. The modified engines were installed on this 2000-horsepower dynamotor stand in a test cell within the Engine Research Building. The researchers could run the engine at different temperatures, fuel-air ratios, and speeds. When the modifications were complete, the improved V–1710 was flight tested on a P–63A Kingcobra loaned to the NACA for this project.

Composite coatings improve engines

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

Funatani, K.; Kurosawa, K.

1994-12-01

About 40% of the power loss in engine systems is attributed to the adverse effects of friction in reciprocating engine components. Over half of this power loss is caused by friction between pistons, piston rings, and cylinder bores. In addition, engine parts may be attacked by corrosive gasoline substitutes such as liquid propane gas and alcohol/gasoline mixtures. To solve both friction and corrosion problems, Nihon Parkerizing Co. has improved the nickel-phosphorus based ceramic composite (NCC) plating technology that was developed for cylinder bores and pistons by Suzuki Motor Co. in the mid 1970s. Iron and nickel-based composite plating technologies havemore » been investigated since the early 1970s, and a few have been used on small two-stroke motorcycle, outboard marine, snowmobile, and some luxury passenger car engine components. Both nickel- and iron-base plating processes are used on cylinders and pistons because they offer excellent wear and corrosion resistance. Nickel-base films have higher corrosion resistance than those based on iron, and are capable of withstanding the corrosive conditions characteristic of high methanol fuels. Unfortunately, they experience a decrease in hardness as operating temperatures increase. However, NCC coatings with phosphorus additions have high hardness even under severe operating conditions, and hardness increases upon exposure to elevated temperatures. In addition to high hardness and corrosion resistance, NCC coatings provide a low friction coefficient, which contributes to the reduction of friction losses between sliding components. When used in low-quality or alcohol fuels, the corrosion resistance of NCC coatings is far higher than that of Fe-P plating. Additionally, the coatings reduce wall and piston temperature, wear of ring groove and skirt, and carbon deposit formation, and they improve output power and torque. These advantages all contribute to the development of light and efficient engines with better fuel mileage.« less

NASA Glenn's Engine Components Research Lab, Cell 2B, Reactivated to Support the U.S. Army Research Laboratory T700 Engine Test

NASA Technical Reports Server (NTRS)

Beltran, Luis R.; Griffin, Thomas A.

2004-01-01

The U.S. Army Vehicle Technology Directorate at the NASA Glenn Research Center has been directed by their parent command, the U.S. Army Research Laboratory (ARL), to demonstrate active stall technology in a turboshaft engine as the next step in transitioning this technology to the Army and aerospace industry. Therefore, the Vehicle Technology Directorate requested the reactivation of Glenn's Engine Components Research Lab, Cell 2B, (ECRL 2B). They wanted to test a T700 engine that had been used previously for turboshaft engine research as a partnership between the Army and NASA on small turbine engine research. ECRL 2B had been placed in standby mode in 1997. Glenn's Testing Division initiated reactivation in May 2002 to support the new research effort, and they completed reactivation and improvements in September 2003.

Qualification of Life Extension Schemes for Engine Components (Homologation des Programmes de Prolongation du cycle de vie des Organes Moteur)

DTIC Science & Technology

1999-03-01

cycle managers include (1) improving the durability of components through material substitution, or the addition of protective coatings, (2) returning... including in service trials, is required to demonstrate that the repaired and/or modified component is safe to use and remains so once returned to...Better Turbine Materials and Technology Including 5 Predicted Life Improvements by T.J. Williams Repair Developments to Fit Customer Needs (Presented

Automotive Stirling engine development program

NASA Technical Reports Server (NTRS)

Ernst, W.; Richey, A.; Farrell, R.; Riecke, G.; Smith, G.; Howarth, R.; Cronin, M.; Simetkosky, M.; Meacher, J.

1986-01-01

The major accomplishments were the completion of the Basic Stirling Engine (BSE) and the Stirling Engine System (SES) designs on schedule, the approval and acceptance of those designs by NASA, and the initiation of manufacture of BSE components. The performance predictions indicate the Mod II engine design will meet or exceed the original program goals of 30% improvement in fuel economy over a conventional Internal Combustion (IC) powered vehicle, while providing acceptable emissions. This was accomplished while simultaneously reducing Mod II engine weight to a level comparable with IC engine power density, and packaging the Mod II in a 1985 Celebrity with no external sheet metal changes. The projected mileage of the Mod II Celebrity for the combined urban and highway CVS cycle is 40.9 mpg which is a 32% improvement over the IC Celebrity. If additional potential improvements are verified and incorporated in the Mod II, the mileage could increase to 42.7 mpg.

Development of manufacturing processes: improved technology for ceramic engine components. Monthly report, August 1977

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

Craig, D.F.; Taylor, A.J.; Weber, G.W.

Progress is described in a research program to develop advanced tooling concepts, processing techniques, and related technology for the economical high-volume manufacture of ceramic engine components. Because of the success of the initial fabrication effort for hot pressing fully dense ceramic turbine blades to shape and/or contour, the effort has been extended to include the fabrication of more complex shapes and the evaluation of alternative pressure-assisted, high-temperature, consolidation methods.

Enhancing calibrated peer review for improved engineering communication education.

DOT National Transportation Integrated Search

2008-01-01

The objectives of this study are to extend Calibrated Peer Review (CPR) to allow for the input and review of visual and verbal components to the process, develop assignments in a set of core engineering courses that use these facilities, assess the i...

Current Trends in Water-in-Diesel Emulsion as a Fuel

PubMed Central

Yahaya Khan, Mohammed; Abdul Karim, Z. A.; Aziz, A. Rashid A.; Tan, Isa M.

2014-01-01

Water-in-diesel emulsion (WiDE) is an alternative fuel for CI engines that can be employed with the existing engine setup with no additional engine retrofitting. It has benefits of simultaneous reduction of both NOx and particulate matters in addition to its impact in the combustion efficiency improvement, although this needs further investigation. This review paper addresses the type of emulsion, the microexplosion phenomenon, emulsion stability and physiochemical improvement, and effect of water content on the combustion and emissions of WiDE fuel. The review also covers the recent experimental methodologies used in the investigation of WiDE for both transport and stationary engine applications. In this review, the fuel injection pump and spray nozzle arrangement has been found to be the most critical components as far as the secondary atomization is concerned and further investigation of the effect of these components in the microexplosion of the emulsion is suggested to be center of focus. PMID:24563631

Metal-Matrix Composites: Status and Prospects

DTIC Science & Technology

1974-12-01

increased to meet or exceed even the most severe engine requirements. This optimism is based largely on an order-of-magnitude improvement in Charpy test...relationships between coupon tests, subsize structural components, and structural component evaluations 4. The development of su-table design

Automotive Stirling engine development program - Overview and status report

NASA Technical Reports Server (NTRS)

Nightingale, N. P.

1983-01-01

The current status of the automotive-Stirling-engine development program being undertaken by DOE and NASA Lewis is reviewed. The program goals and the reference-engine design are explained, and the modifications introduced to improve performance and lower manufacturing costs are discussed and illustrated, including part-power optimization; increased operating temperature (from 720 to 820 C); 45.4-kg weight reduction; elimination of Co and reduction of Cr used; and improved seals, ceramic components, and high-temperature alloys. The test program, some difficulties encountered, and results after 2042 h are summarized.

Current Challenges for HTCMC Aero-Propulsion Components

NASA Technical Reports Server (NTRS)

DiCarlo, James A.; Bansal, Narottam P.

2007-01-01

In comparison to the best metallic materials, HTCMC aero-propulsion engine components offer the opportunity of reduced weight and higher temperature operation, with corresponding improvements in engine cooling requirements, emissions, thrust, and specific fuel consumption. Although much progress has been made in the development of advanced HTCMC constituent materials and processes, major challenges still remain for their implementation into these components. The objectives of this presentation are to briefly review (1) potential HTCMC aero-propulsion components and their generic material performance requirements, (2) recent progress at NASA and elsewhere concerning advanced constituents and processes for meeting these requirements, (3) key HTCMC component implementation challenges that are currently being encountered, and (4) on-going activities within the new NASA Fundamental Aeronautics Program that are addressing these challenges.

Health management and controls for earth to orbit propulsion systems

NASA Technical Reports Server (NTRS)

Bickford, R. L.

1992-01-01

Fault detection and isolation for advanced rocket engine controllers are discussed focusing on advanced sensing systems and software which significantly improve component failure detection for engine safety and health management. Aerojet's Space Transportation Main Engine controller for the National Launch System is the state of the art in fault tolerant engine avionics. Health management systems provide high levels of automated fault coverage and significantly improve vehicle delivered reliability and lower preflight operations costs. Key technologies, including the sensor data validation algorithms and flight capable spectrometers, have been demonstrated in ground applications and are found to be suitable for bridging programs into flight applications.

Improved structural integrity through advances in reliable residual stress measurement: the impact of ENGIN-X

NASA Astrophysics Data System (ADS)

Edwards, L.; Santisteban, J. R.

The determination of accurate reliable residual stresses is critical to many fields of structural integrity. Neutron stress measurement is a non-destructive technique that uniquely provides insights into stress fields deep within engineering components and structures. As such, it has become an increasingly important tool within engineering, leading to improved manufacturing processes to reduce stress and distortion as well as to the definition of more precise lifing procedures. This paper describes the likely impact of the next generation of dedicated engineering stress diffractometers currently being constructed and the utility of the technique using examples of residual stresses both beneficial and detrimental to structural integrity.

Study on Fault Diagnostics of a Turboprop Engine Using Inverse Performance Model and Artificial Intelligent Methods

NASA Astrophysics Data System (ADS)

Kong, Changduk; Lim, Semyeong

2011-12-01

Recently, the health monitoring system of major gas path components of gas turbine uses mostly the model based method like the Gas Path Analysis (GPA). This method is to find quantity changes of component performance characteristic parameters such as isentropic efficiency and mass flow parameter by comparing between measured engine performance parameters such as temperatures, pressures, rotational speeds, fuel consumption, etc. and clean engine performance parameters without any engine faults which are calculated by the base engine performance model. Currently, the expert engine diagnostic systems using the artificial intelligent methods such as Neural Networks (NNs), Fuzzy Logic and Genetic Algorithms (GAs) have been studied to improve the model based method. Among them the NNs are mostly used to the engine fault diagnostic system due to its good learning performance, but it has a drawback due to low accuracy and long learning time to build learning data base if there are large amount of learning data. In addition, it has a very complex structure for finding effectively single type faults or multiple type faults of gas path components. This work builds inversely a base performance model of a turboprop engine to be used for a high altitude operation UAV using measured performance data, and proposes a fault diagnostic system using the base engine performance model and the artificial intelligent methods such as Fuzzy logic and Neural Network. The proposed diagnostic system isolates firstly the faulted components using Fuzzy Logic, then quantifies faults of the identified components using the NN leaned by fault learning data base, which are obtained from the developed base performance model. In leaning the NN, the Feed Forward Back Propagation (FFBP) method is used. Finally, it is verified through several test examples that the component faults implanted arbitrarily in the engine are well isolated and quantified by the proposed diagnostic system.

Energy Efficient Engine (E3) controls and accessories detail design report

NASA Technical Reports Server (NTRS)

Beitler, R. S.; Lavash, J. P.

1982-01-01

An Energy Efficient Engine program has been established by NASA to develop technology for improving the energy efficiency of future commercial transport aircraft engines. As part of this program, a new turbofan engine was designed. This report describes the fuel and control system for this engine. The system design is based on many of the proven concepts and component designs used on the General Electric CF6 family of engines. One significant difference is the incorporation of digital electronic computation in place of the hydromechanical computation currently used.

NASA Lewis F100 engine testing

NASA Technical Reports Server (NTRS)

Werner, R. A.; Willoh, R. G., Jr.; Abdelwahab, M.

1984-01-01

Two builds of an F100 engine model derivative (EMD) engine were evaluated for improvements in engine components and digital electronic engine control (DEEC) logic. Two DEEC flight logics were verified throughout the flight envelope in support of flight clearance for the F100 engine model derivative program (EMPD). A nozzle instability and a faster augmentor transient capability was investigated in support of the F-15 DEEC flight program. Off schedule coupled system mode fan flutter, DEEC nose-boom pressure correlation, DEEC station six pressure comparison, and a new fan inlet variable vane (CIVV) schedule are identified.

Investigation of performance deterioration of the CF6/JT9D, high-bypass ratio turbofan engines

NASA Technical Reports Server (NTRS)

Ziemianski, J. A.; Mehalic, C. M.

1980-01-01

The aircraft energy efficiency program within NASA is developing technology required to improve the fuel efficiency of commercial subsonic transport aricraft. One segment of this program includes engine diagnostics which is directed toward determining the sources and causes of performance deterioration in the Pratt and Whitney Aircraft JT9D and General Electric CF6 high-bypass ratio turbofan engines and developing technology for minimizing the performance losses. Results of engine performance deterioration investigations based on historical data, special engine tests, and specific tests to define the influence of flight loads and component clearances on performance are presented. The results of analysis of several damage mechanisms that contribute to performance deterioration such as blade tip rubs, airfoil surface roughness and erosion, and thermal distortion are also included. The significance of these damage mechanisms on component and overall engine performance is discussed.

Energy Efficient Engine Flight Propulsion System Preliminary Analysis and Design Report

NASA Technical Reports Server (NTRS)

Bisset, J. W.; Howe, D. C.

1983-01-01

The final design and analysis of the flight propulsion system is presented. This system is the conceptual study engine defined to meet the performance, economic and environmental goals established for the Energy Efficient Engine Program. The design effort included a final definition of the engine, major components, internal subsystems, and nacelle. Various analytical representations and results from component technology programs are used to verify aerodynamic and structural design concepts and to predict performance. Specific design goals and specifications, reflecting future commercial aircraft propulsion system requirements for the mid-1980's, are detailed by NASA and used as guidelines during engine definition. Information is also included which details salient results from a separate study to define a turbofan propulsion system, known as the maximum efficiency engine, which reoptimized the advanced fuel saving technologies for improved fuel economy and direct operating costs relative to the flight propulsion system.

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.

Aerothermal modeling. Executive summary

NASA Technical Reports Server (NTRS)

Kenworthy, M. K.; Correa, S. M.; Burrus, D. L.

1983-01-01

One of the significant ways in which the performance level of aircraft turbine engines has been improved is by the use of advanced materials and cooling concepts that allow a significant increase in turbine inlet temperature level, with attendant thermodynamic cycle benefits. Further cycle improvements have been achieved with higher pressure ratio compressors. The higher turbine inlet temperatures and compressor pressure ratios with corresponding higher temperature cooling air has created a very hostile environment for the hot section components. To provide the technology needed to reduce the hot section maintenance costs, NASA has initiated the Hot Section Technology (HOST) program. One key element of this overall program is the Aerothermal Modeling Program. The overall objective of his program is to evolve and validate improved analysis methods for use in the design of aircraft turbine engine combustors. The use of such combustor analysis capabilities can be expected to provide significant improvement in the life and durability characteristics of both combustor and turbine components.

Synthetic biology through biomolecular design and engineering.

PubMed

Channon, Kevin; Bromley, Elizabeth H C; Woolfson, Derek N

2008-08-01

Synthetic biology is a rapidly growing field that has emerged in a global, multidisciplinary effort among biologists, chemists, engineers, physicists, and mathematicians. Broadly, the field has two complementary goals: To improve understanding of biological systems through mimicry and to produce bio-orthogonal systems with new functions. Here we review the area specifically with reference to the concept of synthetic biology space, that is, a hierarchy of components for, and approaches to generating new synthetic and functional systems to test, advance, and apply our understanding of biological systems. In keeping with this issue of Current Opinion in Structural Biology, we focus largely on the design and engineering of biomolecule-based components and systems.

PVD thermal barrier coating applications and process development for aircraft engines

NASA Astrophysics Data System (ADS)

Rigney, D. V.; Viguie, R.; Wortman, D. J.; Skelly, D. W.

1997-06-01

Thermal barrier coatings (TBCs) have been developed for application to aircraft engine components to improve service life in an increasingly hostile thermal environment. The choice of TBC type is related to the component, intended use, and economics. Selection of electron beam physical vapor deposition proc-essing for turbine blade is due in part to part size, surface finish requirements, thickness control needs, and hole closure issues. Process development of PVD TBCs has been carried out at several different sites, including GE Aircraft Engines (GEAE). The influence of processing variables on microstructure is dis-cussed, along with the GEAE development coater and initial experiences of pilot line operation.

Ceramic applications in turbine engines. [for improved component performance and reduced fuel usage

NASA Technical Reports Server (NTRS)

Hudson, M. S.; Janovicz, M. A.; Rockwood, F. A.

1980-01-01

Ceramic material characterization and testing of ceramic nozzle vanes, turbine tip shrouds, and regenerators disks at 36 C above the baseline engine TIT and the design, analysis, fabrication and development activities are described. The design of ceramic components for the next generation engine to be operated at 2070 F was completed. Coupons simulating the critical 2070 F rotor blade was hot spin tested for failure with sufficient margin to quality sintered silicon nitride and sintered silicon carbide, validating both the attachment design and finite element strength. Progress made in increasing strength, minimizing variability, and developing nondestructive evaluation techniques is reported.

Evaluation of Current Assessment Methods in Engineering Entrepreneurship Education

ERIC Educational Resources Information Center

Purzer, Senay; Fila, Nicholas; Nataraja, Kavin

2016-01-01

Quality assessment is an essential component of education that allows educators to support student learning and improve educational programs. The purpose of this study is to evaluate the current state of assessment in engineering entrepreneurship education. We identified 52 assessment instruments covered in 29 journal articles and conference…

Spatial Ability through Engineering Graphics Education

ERIC Educational Resources Information Center

Marunic, Gordana; Glazar, Vladimir

2013-01-01

Spatial ability has been confirmed to be of particular importance for successful engineering graphics education and to be a component of human intelligence that can be improved through instruction and training. Consequently, the creation and communication by means of graphics demand careful development of spatial skills provided by the balanced…

Thermal barrier coatings application in diesel engines

NASA Technical Reports Server (NTRS)

Fairbanks, J. W.

1995-01-01

Commercial use of thermal barrier coatings in diesel engines began in the mid 70's by Dr. Ingard Kvernes at the Central Institute for Industrial Research in Oslo, Norway. Dr. Kvernes attributed attack on diesel engine valves and piston crowns encountered in marine diesel engines in Norwegian ships as hot-corrosion attributed to a reduced quality of residual fuel. His solution was to coat these components to reduce metal temperature below the threshold of aggressive hot-corrosion and also provide protection. Roy Kamo introduced thermal barrier coatings in his 'Adiabatic Diesel Engine' in the late 70's. Kamo's concept was to eliminate the engine block water cooling system and reduce heat losses. Roy reported significant performance improvements in his thermally insulated engine at the SAE Congress in 1982. Kamo's work stimulates major programs with insulated engines, particularly in Europe. Most of the major diesel engine manufacturers conducted some level of test with insulated combustion chamber components. They initially ran into increased fuel consumption. The German engine consortium had Prof. Woschni of the Technical Institute in Munich. Woschni conducted testing with pistons with air gaps to provide the insulation effects. Woschni indicated the hot walls of the insulated engine created a major increase in heat transfer he refers to as 'convection vive.' Woschni's work was a major factor in the abrupt curtailment of insulated diesel engine work in continental Europe. Ricardo in the UK suggested that combustion should be reoptimized for the hot-wall effects of the insulated combustion chamber and showed under a narrow range of conditions fuel economy could be improved. The Department of Energy has supported thermal barrier coating development for diesel engine applications. In the Clean Diesel - 50 Percent Efficient (CD-50) engine for the year 2000, thermal barrier coatings will be used on piston crowns and possibly other components. The primary purpose of the thermal barrier coatings will be to reduce thermal fatigue as the engine peak cylinder pressure will nearly be doubled. As the coatings result in higher available energy in the exhaust gas, efficiency gains are achieved through use of this energy by turbochargers, turbocompounding or thermoelectric generators.

Variable cycle engines for advanced supersonic transports

NASA Technical Reports Server (NTRS)

Howlett, R. A.; Kozlowski, H.

1975-01-01

Variable Cycle Engines being studied for advanced commercial supersonic transports show potential for significant environmental and economic improvements relative to 1st generation SST engines. The two most promising concepts are: a Variable Stream Control Engine and a Variable Cycle Engine with a rear flow-control valve. Each concept utilizes variable components and separate burners to provide independent temperature and velocity control for two coannular flow streams. Unique fuel control techniques are combined with cycle characteristics that provide low fuel consumption, similar to a turbojet engine, for supersonic operation. This is accomplished while retaining the good subsonic performance features of a turbofan engine. A two-stream coannular nozzle shows potential to reduce jet noise to below FAR Part 36 without suppressors. Advanced burner concepts have the potential for significant reductions in exhaust emissions. In total, these unique engine concepts have the potential for significant overall improvements to the environmental and economic characteristics of advanced supersonic transports.

Aircraft energy efficiency. Overview

NASA Technical Reports Server (NTRS)

1981-01-01

Six advanced technology development projects that could cut fuel consumption of future civil air transports by as much as 50 percent are highlighted. These include improved engine components; better engine design; thin short blades for turboprop aircaft; using composite primary structures for weight reduction; the use of supercritical wings, higher aspect ratio, and winglets for improved aerodynamics; active controls; and laminar flow control. The time span of each of the six efforts and NASA's expected expenditures are also discussed.

Baseline automotive gas turbine engine development program

NASA Technical Reports Server (NTRS)

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

1979-01-01

Tests results on a baseline engine are presented to document the automotive gas turbine state-of-the-art at the start of the program. The performance characteristics of the engine and of a vehicle powered by this engine are defined. Component improvement concepts in the baseline engine were evaluated on engine dynamometer tests in the complete vehicle on a chassis dynamometer and on road tests. The concepts included advanced combustors, ceramic regenerators, an integrated control system, low cost turbine material, a continuously variable transmission, power-turbine-driven accessories, power augmentation, and linerless insulation in the engine housing.

Engine component improvement: Performance improvement, JT9D-7 3.8 AR fan

NASA Technical Reports Server (NTRS)

Gaffin, W. O.

1980-01-01

A redesigned, fuel efficient fan for the JT9D-7 engine was tested. Tests were conducted to determine the effect of the 3.8 AR fan on performance, stability, operational characteristics, and noise of the JT9D-7 engine relative to the current 4.6 AR Bill-of-Material fan. The 3.8 AR fan provides increased fan efficiency due to a more advanced blade airfoil with increased chord, eliminating one part span shroud and reducing the number of fan blades and fan exit guide vanes. Engine testing at simulated cruise conditions demonstrated the predicted 1.3 percent improvement in specific fuel consumption with the redesigned 3.8 AR fan. Flight testing and sea level stand engine testing demonstrated exhaust gas temperature margins, fan and low pressure compressor stability, operational suitability, and noise levels comparable to the Bill-of-Material fan.

Overview of thermal barrier coatings in diesel engines

NASA Technical Reports Server (NTRS)

Yonushonis, Thomas M.

1995-01-01

An understanding of delamination mechanisms in thermal barrier coatings has been developed for diesel engine applications through rig tests, structural analysis modeling, nondestructive evaluation, and engine evaluation of various thermal barrier coatings. This knowledge has resulted in improved thermal barrier coatings which survive abusive cyclic fatigue tests in high output diesel engines. Although much conflicting literature now exists regarding the impact of thermal barrier coatings on engine performance and fuel consumption, the changes in fuel consumption appear to be less than a few percent and can be negative for state-of-the-art diesel engines. The ability of the thermal barrier coating to improve fuel economy tends to be dependent on a number of factors including the fuel injection system, combustion chamber design, and the initial engine fuel economy. Limited investigations on state-of-the-art diesel engines have indicated that the surface connected porosity and coating surface roughness may influence engine fuel economy. Current research efforts on thermal barrier coatings are primarily directed at reducing in-cylinder heat rejection, thermal fatigue protection of underlying metal surfaces and a possible reduction in diesel engine emissions. Significant efforts are still required to improve the plasma spray processing capability and the economics for complex geometry diesel engine components.

Enabling Technologies for Ceramic Hot Section Components

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

Venkat Vedula; Tania Bhatia

Silicon-based ceramics are attractive materials for use in gas turbine engine hot sections due to their high temperature mechanical and physical properties as well as lower density than metals. The advantages of utilizing ceramic hot section components include weight reduction, and improved efficiency as well as enhanced power output and lower emissions as a result of reducing or eliminating cooling. Potential gas turbine ceramic components for industrial, commercial and/or military high temperature turbine applications include combustor liners, vanes, rotors, and shrouds. These components require materials that can withstand high temperatures and pressures for long duration under steam-rich environments. For Navymore » applications, ceramic hot section components have the potential to increase the operation range. The amount of weight reduced by utilizing a lighter gas turbine can be used to increase fuel storage capacity while a more efficient gas turbine consumes less fuel. Both improvements enable a longer operation range for Navy ships and aircraft. Ceramic hot section components will also be beneficial to the Navy's Growth Joint Strike Fighter (JSF) and VAATE (Versatile Affordable Advanced Turbine Engines) initiatives in terms of reduced weight, cooling air savings, and capability/cost index (CCI). For DOE applications, ceramic hot section components provide an avenue to achieve low emissions while improving efficiency. Combustors made of ceramic material can withstand higher wall temperatures and require less cooling air. Ability of the ceramics to withstand high temperatures enables novel combustor designs that have reduced NO{sub x}, smoke and CO levels. In the turbine section, ceramic vanes and blades do not require sophisticated cooling schemes currently used for metal components. The saved cooling air could be used to further improve efficiency and power output. The objectives of this contract were to develop technologies critical for ceramic hot section components for gas turbine engines. Significant technical progress has been made towards maturation of the EBC and CMC technologies for incorporation into gas turbine engine hot-section. Promising EBC candidates for longer life and/or higher temperature applications relative to current state of the art BSAS-based EBCs have been identified. These next generation coating systems have been scaled-up from coupons to components and are currently being field tested in Solar Centaur 50S engine. CMC combustor liners were designed, fabricated and tested in a FT8 sector rig to demonstrate the benefits of a high temperature material system. Pretest predictions made through the use of perfectly stirred reactor models showed a 2-3x benefit in CO emissions for CMC versus metallic liners. The sector-rig test validated the pretest predictions with >2x benefit in CO at the same NOx levels at various load conditions. The CMC liners also survived several trip shut downs thereby validating the CMC design methodology. Significant technical progress has been made towards incorporation of ceramic matrix composites (CMC) and environmental barrier coatings (EBC) technologies into gas turbine engine hot-section. The second phase of the program focused on the demonstration of a reverse flow annular CMC combustor. This has included overcoming the challenges of design and fabrication of CMCs into 'complex' shapes; developing processing to apply EBCs to 'engine hardware'; testing of an advanced combustor enabled by CMCs in a PW206 rig; and the validation of performance benefits against a metal baseline. The rig test validated many of the pretest predictions with a 40-50% reduction in pattern factor compared to the baseline and reductions in NOx levels at maximum power conditions. The next steps are to develop an understanding of the life limiting mechanisms in EBC and CMC materials, developing a design system for EBC coated CMCs and durability testing in an engine environment.« less

Study of Technological Improvements in Automobile Fuel Consumption : Volume 2. Comprehensive Discussion.

DOT National Transportation Integrated Search

1974-12-01

A study was conducted to determine the potential reduction in automotive fuel consumption based on the use of innovative systems and improved components. Technological areas investigated were: spark ignited engines with and without turbocharging, ele...

Study of Technological Improvements in Automobile Fuel Consumption : Volume 1. Executive Summary.

DOT National Transportation Integrated Search

1974-02-01

A study was conducted to determine the potential reduction in automotive fuel consumption based on the use of innovative systems and improved components. Technological areas investigated were: spark ignited engines with and without turbocharging, ele...

Specialized data analysis for the Space Shuttle Main Engine and diagnostic evaluation of advanced propulsion system components

NASA Technical Reports Server (NTRS)

1993-01-01

The Marshall Space Flight Center is responsible for the development and management of advanced launch vehicle propulsion systems, including the Space Shuttle Main Engine (SSME), which is presently operational, and the Space Transportation Main Engine (STME) under development. The SSME's provide high performance within stringent constraints on size, weight, and reliability. Based on operational experience, continuous design improvement is in progress to enhance system durability and reliability. Specialized data analysis and interpretation is required in support of SSME and advanced propulsion system diagnostic evaluations. Comprehensive evaluation of the dynamic measurements obtained from test and flight operations is necessary to provide timely assessment of the vibrational characteristics indicating the operational status of turbomachinery and other critical engine components. Efficient performance of this effort is critical due to the significant impact of dynamic evaluation results on ground test and launch schedules, and requires direct familiarity with SSME and derivative systems, test data acquisition, and diagnostic software. Detailed analysis and evaluation of dynamic measurements obtained during SSME and advanced system ground test and flight operations was performed including analytical/statistical assessment of component dynamic behavior, and the development and implementation of analytical/statistical models to efficiently define nominal component dynamic characteristics, detect anomalous behavior, and assess machinery operational condition. In addition, the SSME and J-2 data will be applied to develop vibroacoustic environments for advanced propulsion system components, as required. This study will provide timely assessment of engine component operational status, identify probable causes of malfunction, and indicate feasible engineering solutions. This contract will be performed through accomplishment of negotiated task orders.

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.

Investigations for the improvement of space shuttle main engine electron beam welding equipment

NASA Technical Reports Server (NTRS)

Smock, R. A.; Taylor, R. A.; Wall, W. A., Jr.

1977-01-01

Progress made in the testing, evaluation, and correction of MSFC's 7.5 kW electron beam welder in support of space shuttle main engine component welding is summarized. The objective of this project was to locate and correct the deficiencies in the welder. Some 17 areas were deficient in the 7.5 kW ERI welding system and the associated corrective action was taken to improve its operational performance. An overall improvement of 20 times the original reliability was obtained at full rated capacity after the modifications were made.

Army Research Concerns in Engine Sealing

NASA Technical Reports Server (NTRS)

Bill, Robert C.

1991-01-01

The Army Propulsion Directorate is primarily concerned with small engine technology, where sealing performance is most critical. Tip leakage and secondary flow losses have a much greater performance impact on small engine aero-components than on large engines. A brief survey and critique of presently employed sealing concepts is presented. Some recent new research thrusts that show promise for substantial improvement are discussed. An especially promising approach for small engine applications is brush seals. Brush seal concepts are being considered for outer air seal and secondary airflow system seal locations.

Study of the costs and benefits of composite materials in advanced turbofan engines

NASA Technical Reports Server (NTRS)

Steinhagen, C. A.; Stotler, C. L.; Neitzel, R. E.

1974-01-01

Composite component designs were developed for a number of applicable engine parts and functions. The cost and weight of each detail component was determined and its effect on the total engine cost to the aircraft manufacturer was ascertained. The economic benefits of engine or nacelle composite or eutectic turbine alloy substitutions was then calculated. Two time periods of engine certification were considered for this investigation, namely 1979 and 1985. Two methods of applying composites to these engines were employed. The first method just considered replacing an existing metal part with a composite part with no other change to the engine. The other method involved major engine redesign so that more efficient composite designs could be employed. Utilization of polymeric composites wherever payoffs were available indicated that a total improvement in Direct Operating Cost (DOC) of 2.82 to 4.64 percent, depending on the engine considered, could be attained. In addition, the percent fuel saving ranged from 1.91 to 3.53 percent. The advantages of using advanced materials in the turbine are more difficult to quantify but could go as high as an improvement in DOC of 2.33 percent and a fuel savings of 2.62 percent. Typically, based on a fleet of one hundred aircraft, a percent savings in DOC represents a savings of four million dollars per year and a percent of fuel savings equals 23,000 cu m (7,000,000 gallons) per year.

Engineering graduates' skill sets in the MENA region: a gap analysis of industry expectations and satisfaction

NASA Astrophysics Data System (ADS)

Ramadi, Eric; Ramadi, Serge; Nasr, Karim

2016-01-01

This study explored gaps between industry expectations and perceptions of engineering graduates' skill sets in the Middle East and North Africa (MENA) region. This study measured the importance that managers of engineers placed on 36 skills relevant to engineers. Also measured was managers' satisfaction with engineering graduates' skill sets. Importance and satisfaction were used to calculate skill gaps for each skill. A principal components analysis was then performed, consolidating the 36 skills into 8 categories. The means of importance, satisfaction, and skill gaps were ranked to determine the areas in which graduates needed improvement. Results showed significant gaps between managers' expectations of and satisfaction with all 36 skills. The areas in which managers felt that graduates needed most improvement were communication, time management, and continuous learning. Managers reported that recent engineering graduates exhibited low overall preparedness for employment. These findings may help to inform curricular reform in engineering education.

Evaluation of Next Generation Thermal Stability-Improving Additives for JP-8, Phase 2 - Specification, Materials, Filtration, and Fit-For-Purpose Evaluations

DTIC Science & Technology

2013-12-01

varnishes and hard carbon deposits in various parts of the fuel system and are commonly referred to as coke or fouling. Depending upon the temperature...this coke . Coke present in an aircraft system, particularly the engine, lowers the on-wing time of engines and can result in significant damage to...engine hot section components. Even with proper scheduled maintenance, the presence of coke in any part of the aircraft or engine system has a

Selected results from combustion research at the Lewis Research Center

NASA Technical Reports Server (NTRS)

Jones, R. E.

1981-01-01

Combustion research at Lewis is organized to provide a balanced program responsive to national needs and the gas turbine industry. The results of this research is a technology base that assists the gas turbine engine manufacturers in developing new and improved combustion systems for advanced civil and military engines with significant improvements in performance, durability, fuel flexibility and control of exhaust emissions. Research efforts consist of fundamentals and modeling, and applied component and combustor research.

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.

Diesel and Truck Certification Needs Assessment: Two Surveys.

ERIC Educational Resources Information Center

Broadbent, William A.

Recommendations for the improvement of the diesel engine and truck components of the Hawaii state certification examination for automobile and truck mechanics were solicited from 14 major private businesses repairing heavy tractor rigs and/or diesel engines on Oahu and a statewide sample of 21 trucking firms and other companies making extensive…

Improved maintainability of space-based reusable rocket engines

NASA Technical Reports Server (NTRS)

Barkhoudarian, S.; Szemenyei, B.; Nelson, R. S.; Pauckert, R.; Harmon, T.

1988-01-01

Advanced, noninferential, noncontacting, in situ measurement technologies, combined with automated testing and expert systems, can provide continuous, automated health monitoring of critical space-based rocket engine components, requiring minimal disassembly and no manual data analysis, thus enhancing their maintainability. This paper concentrates on recent progress of noncontacting combustion chamber wall thickness condition-monitoring technologies.

Improved design of a tangential entry cyclone separator for separation of particles from exhaust gas of diesel engine.

PubMed

Mukhopadhyay, N

2011-01-01

An effective design of cyclone separator with tangential inlet is developed applying an equation derived from the correlation of collection efficiency with maximum pressure drop components of the cyclone, which can efficiently remove the particles around 1microm of the exhaust gas of diesel engine.

Introducing Whole-Systems Design to First-Year Engineering Students with Case Studies

ERIC Educational Resources Information Center

Blizzard, Jackie; Klotz, Leidy; Pradhan, Alok; Dukes, Michael

2012-01-01

Purpose: A whole-systems approach, which seeks to optimize an entire system for multiple benefits, not isolated components for single benefits, is essential to engineering design for radically improved sustainability performance. Based on real-world applications of whole-systems design, the Rocky Mountain Institute (RMI) is developing educational…

Application of High Speed Digital Image Correlation in Rocket Engine Hot Fire Testing

NASA Technical Reports Server (NTRS)

Gradl, Paul R.; Schmidt, Tim

2016-01-01

Hot fire testing of rocket engine components and rocket engine systems is a critical aspect of the development process to understand performance, reliability and system interactions. Ground testing provides the opportunity for highly instrumented development testing to validate analytical model predictions and determine necessary design changes and process improvements. To properly obtain discrete measurements for model validation, instrumentation must survive in the highly dynamic and extreme temperature application of hot fire testing. Digital Image Correlation has been investigated and being evaluated as a technique to augment traditional instrumentation during component and engine testing providing further data for additional performance improvements and cost savings. The feasibility of digital image correlation techniques were demonstrated in subscale and full scale hotfire testing. This incorporated a pair of high speed cameras to measure three-dimensional, real-time displacements and strains installed and operated under the extreme environments present on the test stand. The development process, setup and calibrations, data collection, hotfire test data collection and post-test analysis and results are presented in this paper.

Thermal barrier coatings for gas-turbine engine applications.

PubMed

Padture, Nitin P; Gell, Maurice; Jordan, Eric H

2002-04-12

Hundreds of different types of coatings are used to protect a variety of structural engineering materials from corrosion, wear, and erosion, and to provide lubrication and thermal insulation. Of all these, thermal barrier coatings (TBCs) have the most complex structure and must operate in the most demanding high-temperature environment of aircraft and industrial gas-turbine engines. TBCs, which comprise metal and ceramic multilayers, insulate turbine and combustor engine components from the hot gas stream, and improve the durability and energy efficiency of these engines. Improvements in TBCs will require a better understanding of the complex changes in their structure and properties that occur under operating conditions that lead to their failure. The structure, properties, and failure mechanisms of TBCs are herein reviewed, together with a discussion of current limitations and future opportunities.

The construction of life prediction models for the design of Stirling engine heater components

NASA Technical Reports Server (NTRS)

Petrovich, A.; Bright, A.; Cronin, M.; Arnold, S.

1983-01-01

The service life of Stirling-engine heater structures of Fe-based high-temperature alloys is predicted using a numerical model based on a linear-damage approach and published test data (engine test data for a Co-based alloy and tensile-test results for both the Co-based and the Fe-based alloys). The operating principle of the automotive Stirling engine is reviewed; the economic and technical factors affecting the choice of heater material are surveyed; the test results are summarized in tables and graphs; the engine environment and automotive duty cycle are characterized; and the modeling procedure is explained. It is found that the statistical scatter of the fatigue properties of the heater components needs to be reduced (by decreasing the porosity of the cast material or employing wrought material in fatigue-prone locations) before the accuracy of life predictions can be improved.

2nd Generation Reusable Launch Vehicle (2G RLV). Revised

NASA Technical Reports Server (NTRS)

Matlock, Steve; Sides, Steve; Kmiec, Tom; Arbogast, Tim; Mayers, Tom; Doehnert, Bill

2001-01-01

This is a revised final report and addresses all of the work performed on this program. Specifically, it covers vehicle architecture background, definition of six baseline engine cycles, reliability baseline (space shuttle main engine QRAS), and component level reliability/performance/cost for the six baseline cycles, and selection of 3 cycles for further study. This report further addresses technology improvement selection and component level reliability/performance/cost for the three cycles selected for further study, as well as risk reduction plans, and recommendation for future studies.

A feasibility work on the applications of MRE to automotive components

NASA Astrophysics Data System (ADS)

Kim, S. H.; Park, Y. J.; Cha, A. R.; Kim, G. W.; Bang, J. H.; Lim, C. S.; Choi, S. B.

2018-03-01

A feasibility work on the application of magneto-rheological elastomers (MREs) to automotive components, such as engine mounts is presented. While vehicle components require the high resonance frequency in terms of ride quality and handling, it is required to have the low resonance frequency to isolate the incoming vibration. With the conventional automotive technologies, it is challenging to combine these two conflicting performance trade-offs, ride quality including handling, and NVH (noise, vibration and harshness). Over the last decades, MREs, one of the new emerging smart materials, have been widely used to resolve this technical limitation. For example, an advanced engine mount was developed by using MRE to isolate the vibration transmitting from engines. In this paper, we will focus on rear cross member bushes, which is a key component for isolating the vibration from the road, and demonstrate their improved performance by utilizing MRE. The resonance frequency shift induced by the stiffness change of MRE will be presented through the frequency response functions estimated by simulation result.

Study of Technological Improvements in Automobile Fuel Consumption : Volume 3B. Appendixes 4 though 7.

DOT National Transportation Integrated Search

1974-12-01

A study was conducted to determine the potential reduction in automotive fuel consumption based on the use of innovative systems and improved components. Technological areas investigated were: spark ignited engines with and without turbocharging, ele...

Study of Technological Improvements in Automobile Fuel Consumption : Volume 3A. Appendixes 1 through 3

DOT National Transportation Integrated Search

1974-12-01

A study was conducted to determine the potential reduction in automotive fuel consumption based on the use of innovative systems and improved components. Technological areas investigated were: spark ignited engines with and without turbocharging, ele...

Assessment of Technologies for Noncryogenic Hybrid Electric Propulsion

NASA Technical Reports Server (NTRS)

Dever, Timothy P.; Duffy, Kirsten P.; Provenza, Andrew J.; Loyselle, Patricia L.; Choi, Benjamin B.; Morrison, Carlos R.; Lowe, Angela M.

2015-01-01

The Subsonic Fixed Wing Project of NASA's Fundamental Aeronautics Program is researching aircraft propulsion technologies that will lower noise, emissions, and fuel burn. One promising technology is noncryogenic electric propulsion, which could be either hybrid electric propulsion or turboelectric propulsion. Reducing dependence on the turbine engine would certainly reduce emissions. However, the weight of the electricmotor- related components that would have to be added would adversely impact the benefits of the smaller turbine engine. Therefore, research needs to be done to improve component efficiencies and reduce component weights. This study projects technology improvements expected in the next 15 and 30 years, including motor-related technologies, power electronics, and energy-storage-related technologies. Motor efficiency and power density could be increased through the use of better conductors, insulators, magnets, bearings, structural materials, and thermal management. Energy storage could be accomplished through batteries, flywheels, or supercapacitors, all of which expect significant energy density growth over the next few decades. A first-order approximation of the cumulative effect of each technology improvement shows that motor power density could be improved from 3 hp/lb, the state of the art, to 8 hp/lb in 15 years and 16 hp/lb in 30 years.

Effects of NOX Storage Component on Ammonia Formation in TWC for Passive SCR NOX Control in Lean Gasoline Engines

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

Prikhodko, Vitaly Y.; Pihl, Josh A.; Toops, Todd J.

A prototype three-way catalyst (TWC) with NOX storage component was evaluated for ammonia (NH3) generation on a 2.0-liter BMW lean burn gasoline direct injection engine as a component in a passive ammonia selective catalytic reduction (SCR) system. The passive NH3 SCR system is a potential approach for controlling nitrogen oxides (NOX) emissions from lean burn gasoline engines. In this system, NH3 is generated over a close-coupled TWC during periodic slightly-rich engine operation and subsequently stored on an underfloor SCR catalyst. Upon switching to lean, NOX passes through the TWC and is reduced by the stored NH3 on the SCR catalyst.more » Adding a NOX storage component to a TWC provides two benefits in the context of a passive SCR system: (1) enabling longer lean operation by storing NOX upstream and preserving NH3 inventory on the downstream SCR catalyst; and (2) increasing the quantity and rate of NH3 production during rich operation. Since the fuel penalty associated with passive SCR NOX control depends on the fraction of time that the engine is running rich rather than lean, both benefits (longer lean times and shorter rich times achieved via improved NH3 production) will decrease the passive SCR fuel penalty. However, these benefits are primarily realized at low to moderate temperatures (300-500 °C), where the NOX storage component is able to store NOX, with little to no benefit at higher temperatures (>500 °C), where NOX storage is no longer effective. This study discusses engine parameters and control strategies affecting the NH3 generation over a TWC with NOX storage component.« less

The Use of an Ultra-Compact Combustor as an Inter-Turbine Burner for Improved Engine Performance

DTIC Science & Technology

2014-03-27

27 25 NPSS Mixed Flow Turbofan Model - Element and Link Names . . . . . . . . . 30 26 VCE with Variable Components Labeled...the power generation, Vogeler proposed the Sequential Combustion Cycle (SCC) for use in aircraft engines [13]. For a conventional turbofan with a...single combustor, thrust is a function of bypass ratio and maximum pressure and temperature in the cycle. Considering a twin spool turbofan engine as

Cost/benefit analysis of advanced material technologies for small aircraft turbine engines

NASA Technical Reports Server (NTRS)

Comey, D. H.

1977-01-01

Cost/benefit studies were conducted on ten advanced material technologies applicable to small aircraft gas turbine engines to be produced in the 1985 time frame. The cost/benefit studies were applied to a two engine, business-type jet aircraft in the 6800- to 9100-Kg (15,000- to 20,000-lb) gross weight class. The new material technologies are intended to provide improvements in the areas of high-pressure turbine rotor components, high-pressure turbine rotor components, high-pressure turbine stator airfoils, and static structural components. The cost/benefit of each technology is presented in terms of relative value, which is defined as a change in life cycle cost times probability of success divided by development cost. Technologies showing the most promising cost/benefits based on relative value are uncooled single crystal MAR-M 247 turbine blades, cooled DS MAR-M 247 turbine blades, and cooled ODS 'M'CrAl laminate turbine stator vanes.

Design of preventive maintenance system using the reliability engineering and maintenance value stream mapping methods in PT. XYZ

NASA Astrophysics Data System (ADS)

Sembiring, N.; Panjaitan, N.; Angelita, S.

2018-02-01

PT. XYZ is a company owned by non-governmental organizations engaged in the field of production of rubber processing becoming crumb rubber. Part of the production is supported by some of machines and interacting equipment to achieve optimal productivity. Types of the machine that are used in the production process are Conveyor Breaker, Breaker, Rolling Pin, Hammer Mill, Mill Roll, Conveyor, Shredder Crumb, and Dryer. Maintenance system in PT. XYZ is corrective maintenance i.e. repairing or replacing the engine components after the crash on the machine. Replacement of engine components on corrective maintenance causes the machine to stop operating during the production process is in progress. The result is in the loss of production time due to the operator must replace the damaged engine components. The loss of production time can impact on the production targets which were not reached and lead to high loss costs. The cost for all components is Rp. 4.088.514.505. This cost is really high just for maintaining a Mill Roll Machine. Therefore PT. XYZ is needed to do preventive maintenance i.e. scheduling engine components and improving maintenance efficiency. The used methods are Reliability Engineering and Maintenance Value Stream Mapping (MVSM). The needed data in this research are the interval of time damage to engine components, opportunity cost, labor cost, component cost, corrective repair time, preventive repair time, Mean Time To Opportunity (MTTO), Mean Time To Repair (MTTR), and Mean Time To Yield (MTTY). In this research, the critical components of Mill Roll machine are Spier, Bushing, Bearing, Coupling and Roll. Determination of damage distribution, reliability, MTTF, cost of failure, cost of preventive, current state map, and future state map are done so that the replacement time for each critical component with the lowest maintenance cost and preparation of Standard Operation Procedure (SOP) are developed. For the critical component that has been determined, the Spier component replacement time interval is 228 days with a reliability value of 0,503171, Bushing component is 240 days with reliability value of 0.36861, Bearing component is 202 days with reliability value of 0,503058, Coupling component is 247 days with reliability value of 0,50108 and Roll component is 301 days with reliability value of 0,373525. The results show that the cost decreases from Rp 300,688,114 to Rp 244,384,371 obtained from corrective maintenance to preventive maintenance. While maintenance efficiency increases with the application of preventive maintenance i.e. for Spier component from 54,0540541% to 74,07407%, Bushing component from 52,3809524% to 68,75%, Bearing component from 40% to 52,63158%, Coupling component from 60.9756098% to 71.42857%, and Roll components from 64.516129% to 74.7663551%.

Automotive Stirling Engine Development Project

NASA Technical Reports Server (NTRS)

Ernst, William D.; Shaltens, Richard K.

1997-01-01

The development and verification of automotive Stirling engine (ASE) component and system technology is described as it evolved through two experimental engine designs: the Mod 1 and the Mod 2. Engine operation and performance and endurance test results for the Mod 1 are summarized. Mod 2 engine and component development progress is traced from the original design through hardware development, laboratory test, and vehicle installation. More than 21,000 hr of testing were accomplished, including 4800 hr with vehicles that were driven more dm 59,000 miles. Mod 2 engine dynamometer tests demonstrated that the engine system configuration had accomplished its performance goals for power (60 kW) and efficiency (38.5%) to within a few percent. Tests with the Mod 2 engine installed in a delivery van demonstrated combined metro-highway fuel economy improvements consistent with engine performance goals and the potential for low emission levels. A modified version of the Mod 2 has been identified as a manufacturable design for an ASE. As part of the ASE project, the Industry Test and Evaluation Program (ITEP), NASA Technology Utilization (TU) project, and the industry-funded Stirling Natural Gas Engine program were undertaken to transfer ASE technology to end users. The results of these technology transfer efforts are also summarized.

Carbon-carbon cylinder block

NASA Technical Reports Server (NTRS)

Ransone, Philip O. (Inventor)

1995-01-01

A lightweight cylinder block composed of carbon-carbon is disclosed. The use of carbon-carbon over conventional materials, such as cast iron or aluminum, reduces the weight of the cylinder block and improves thermal efficiency of the internal combustion reciprocating engine. Due to the negligible coefficient of thermal expansion and unique strength at elevated temperatures of carbon-carbon, the piston-to-cylinder wall clearance can be small, especially when the carbon-carbon cylinder block is used in conjunction with a carbon-carbon piston. Use of the carbon-carbon cylinder has the effect of reducing the weight of other reciprocating engine components allowing the piston to run at higher speeds and improving specific engine performance.

Cost effective launch operations of the SSME

NASA Technical Reports Server (NTRS)

Klatt, F. P.

1985-01-01

The Space Shuttle Main Engine (SSME) represents the beginning of reusable rocket engine operations in the space transportation system (STS). Steps taken to reduce the overall cost of flight operations of the SSME by improving turnaround operations, extending the life of the engine, and improving the cost effectiveness of overhaul operations at the Canoga Park home plant are described. Ground certification testing to ensure safe launch operations is described, as well as certification extension testing that leads to a service life equivalent to 40 flights. The proven flight record of the SSME, which has demonstrated the utility of the SSME as a key component of America's space transportation system, is discussed.

Draftsmen Create a Blade Template in the Materials and Stresses Building

NASA Image and Video Library

1953-04-21

Draftsmen in the Materials and Stresses Building at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory create a template for a compressor using actual compressor blades. The Compressor and Turbine Division contained four sections of researchers dedicated to creating better engine components. The Materials and Thermodynamics Division studied the strength, durability, heat transfer characteristics, and physical composition of various materials. The two divisions were important to the research and development of new aircraft engines. The constant battle to increase the engine’s thrust while decreasing its overall weight resulted in additional stress on jet engine components, particularly compressors. As speed and maneuverability were enhanced, the strain on the engines and inlets grew. For decades NACA Lewis researchers continually sought to improve compressor blade design, develop stronger composite materials, and minimize flutter and inlet distortions.

Wave-Rotor-Enhanced Gas Turbine Engine Demonstrator

NASA Technical Reports Server (NTRS)

Welch, Gerard E.; Paxson, Daniel E.; Wilson, Jack; Synder, Philip H.

1999-01-01

The U.S. Army Research Laboratory, NASA Glenn Research Center, and Rolls-Royce Allison are working collaboratively to demonstrate the benefits and viability of a wave-rotor-topped gas turbine engine. The self-cooled wave rotor is predicted to increase the engine overall pressure ratio and peak temperature by 300% and 25 to 30%. respectively, providing substantial improvements in engine efficiency and specific power. Such performance improvements would significantly reduce engine emissions and the fuel logistics trails of armed forces. Progress towards a planned demonstration of a wave-rotor-topped Rolls-Royce Allison model 250 engine has included completion of the preliminary design and layout of the engine, the aerodynamic design of the wave rotor component and prediction of its aerodynamic performance characteristics in on- and off-design operation and during transients, and the aerodynamic design of transition ducts between the wave rotor and the high pressure turbine. The topping cycle increases the burner entry temperature and poses a design challenge to be met in the development of the demonstrator engine.

A Fully Non-metallic Gas Turbine Engine Enabled by Additive Manufacturing

NASA Technical Reports Server (NTRS)

Grady, Joseph E.

2014-01-01

The Non-Metallic Gas Turbine Engine project, funded by NASA Aeronautics Research Institute (NARI), represents the first comprehensive evaluation of emerging materials and manufacturing technologies that will enable fully nonmetallic gas turbine engines. This will be achieved by assessing the feasibility of using additive manufacturing technologies for fabricating polymer matrix composite (PMC) and ceramic matrix composite (CMC) gas turbine engine components. The benefits of the proposed effort include: 50 weight reduction compared to metallic parts, reduced manufacturing costs due to less machining and no tooling requirements, reduced part count due to net shape single component fabrication, and rapid design change and production iterations. Two high payoff metallic components have been identified for replacement with PMCs and will be fabricated using fused deposition modeling (FDM) with high temperature capable polymer filaments. The first component is an acoustic panel treatment with a honeycomb structure with an integrated back sheet and perforated front sheet. The second component is a compressor inlet guide vane. The CMC effort, which is starting at a lower technology readiness level, will use a binder jet process to fabricate silicon carbide test coupons and demonstration articles. The polymer and ceramic additive manufacturing efforts will advance from monolithic materials toward silicon carbide and carbon fiber reinforced composites for improved properties. Microstructural analysis and mechanical testing will be conducted on the PMC and CMC materials. System studies will assess the benefits of fully nonmetallic gas turbine engine in terms of fuel burn, emissions, reduction of part count, and cost. The proposed effort will be focused on a small 7000 lbf gas turbine engine. However, the concepts are equally applicable to large gas turbine engines. The proposed effort includes a multidisciplinary, multiorganization NASA - industry team that includes experts in ceramic materials and CMCs, polymers and PMCs, structural engineering, additive manufacturing, engine design and analysis, and system analysis.

Re-engineering pre-employment check-up systems: a model for improving health services.

PubMed

Rateb, Said Abdel Hakim; El Nouman, Azza Abdel Razek; Rateb, Moshira Abdel Hakim; Asar, Mohamed Naguib; El Amin, Ayman Mohammed; Gad, Saad abdel Aziz; Mohamed, Mohamed Salah Eldin

2011-01-01

The purpose of this paper is to develop a model for improving health services provided by the pre-employment medical fitness check-up system affiliated to Egypt's Health Insurance Organization (HIO). Operations research, notably system re-engineering, is used in six randomly selected centers and findings before and after re-engineering are compared. The re-engineering model follows a systems approach, focusing on three areas: structure, process and outcome. The model is based on six main components: electronic booking, standardized check-up processes, protected medical documents, advanced archiving through an electronic content management (ECM) system, infrastructure development, and capacity building. The model originates mainly from customer needs and expectations. The centers' monthly customer flow increased significantly after re-engineering. The mean time spent per customer cycle improved after re-engineering--18.3 +/- 5.5 minutes as compared to 48.8 +/- 14.5 minutes before. Appointment delay was also significantly decreased from an average 18 to 6.2 days. Both beneficiaries and service providers were significantly more satisfied with the services after re-engineering. The model proves that re-engineering program costs are exceeded by increased revenue. Re-engineering in this study involved multiple structure and process elements. The literature review did not reveal similar re-engineering healthcare packages. Therefore, each element was compared separately. This model is highly recommended for improving service effectiveness and efficiency. This research is the first in Egypt to apply the re-engineering approach to public health systems. Developing user-friendly models for service improvement is an added value.

Implementation of 3D virtual learning environment to improve students’ cognitive achievement

NASA Astrophysics Data System (ADS)

Rasim; Langi, A. Z. R.; Rosmansyah, Y.; Munir

2018-05-01

Virtual Learning Environment (VLE) has been widely used in assisting learning. This study aims to implement VLE-based learning in software engineering course. VLE provides many facilities for learning. In this research, VLE components used were presenter and quiz chair components. Evaluation results showed a significant difference from classical learning.

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

Engineering evaluation of SSME dynamic data from engine tests and SSV flights

NASA Technical Reports Server (NTRS)

1986-01-01

An engineering evaluation of dynamic data from SSME hot firing tests and SSV flights is summarized. The basic objective of the study is to provide analyses of vibration, strain and dynamic pressure measurements in support of MSFC performance and reliability improvement programs. A brief description of the SSME test program is given and a typical test evaluation cycle reviewed. Data banks generated to characterize SSME component dynamic characteristics are described and statistical analyses performed on these data base measurements are discussed. Analytical models applied to define the dynamic behavior of SSME components (such as turbopump bearing elements and the flight accelerometer safety cut-off system) are also summarized. Appendices are included to illustrate some typical tasks performed under this study.

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

NASA Technical Reports Server (NTRS)

1980-01-01

Progress in the development of a gas turbine engine to improve fuel economy, reduce gaseous emissions and particulate levels, and compatible with a variety of alternate fuels is reported. The powertrain is designated AGT101 and consists of a regenerated single shaft gas turbine engine, a split differential gearbox and a Ford Automatic Overdrive production transmission. The powertrain is controlled by an electronic digital microprocessor and associated actuators, instrumentation, and sensors. Standard automotive accessories are driven by engine power provided by an accessory pad on the gearbox. Component/subsystem development progress is reported in the following areas: compressor, turbine, combustion system, regenerator, gearbox/transmission, structures, ceramic components, foil gas bearing, bearings and seals, rotor dynamics, and controls and accessories.

Applicability of a Crack-Detection System for Use in Rotor Disk Spin Test Experiments Being Evaluated

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali; Baaklini, George Y.; Roth, Don J.

2004-01-01

Engine makers and aviation safety government institutions continue to have a strong interest in monitoring the health of rotating components in aircraft engines to improve safety and to lower maintenance costs. To prevent catastrophic failure (burst) of the engine, they use nondestructive evaluation (NDE) and major overhauls for periodic inspections to discover any cracks that might have formed. The lowest cost fluorescent penetrant inspection NDE technique can fail to disclose cracks that are tightly closed during rest or that are below the surface. The NDE eddy current system is more effective at detecting both crack types, but it requires careful setup and operation and only a small portion of the disk can be practically inspected. So that sensor systems can sustain normal function in a severe environment, health-monitoring systems require the sensor system to transmit a signal if a crack detected in the component is above a predetermined length (but below the length that would lead to failure) and lastly to act neutrally upon the overall performance of the engine system and not interfere with engine maintenance operations. Therefore, more reliable diagnostic tools and high-level techniques for detecting damage and monitoring the health of rotating components are very essential in maintaining engine safety and reliability and in assessing life.

Tissue engineered constructs for peripheral nerve surgery

PubMed Central

Johnson, P. J.; Wood, M. D.; Moore, A. M.; Mackinnon, S. E.

2013-01-01

Summary Background Tissue engineering has been defined as “an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function or a whole organ”. Traumatic peripheral nerve injury resulting in significant tissue loss at the zone of injury necessitates the need for a bridge or scaffold for regenerating axons from the proximal stump to reach the distal stump. Methods A review of the literature was used to provide information on the components necessary for the development of a tissue engineered peripheral nerve substitute. Then, a comprehensive review of the literature is presented composed of the studies devoted to this goal. Results Extensive research has been directed toward the development of a tissue engineered peripheral nerve substitute to act as a bridge for regenerating axons from the proximal nerve stump seeking the distal nerve. Ideally this nerve substitute would consist of a scaffold component that mimics the extracellular matrix of the peripheral nerve and a cellular component that serves to stimulate and support regenerating peripheral nerve axons. Conclusions The field of tissue engineering should consider its challenge to not only meet the autograft “gold standard” but also to understand what drives and inhibits nerve regeneration in order to surpass the results of an autograft. PMID:24385980

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.

Improved NASA-ANOPP Noise Prediction Computer Code for Advanced Subsonic Propulsion Systems

NASA Technical Reports Server (NTRS)

Kontos, K. B.; Janardan, B. A.; Gliebe, P. R.

1996-01-01

Recent experience using ANOPP to predict turbofan engine flyover noise suggests that it over-predicts overall EPNL by a significant amount. An improvement in this prediction method is desired for system optimization and assessment studies of advanced UHB engines. An assessment of the ANOPP fan inlet, fan exhaust, jet, combustor, and turbine noise prediction methods is made using static engine component noise data from the CF6-8OC2, E(3), and QCSEE turbofan engines. It is shown that the ANOPP prediction results are generally higher than the measured GE data, and that the inlet noise prediction method (Heidmann method) is the most significant source of this overprediction. Fan noise spectral comparisons show that improvements to the fan tone, broadband, and combination tone noise models are required to yield results that more closely simulate the GE data. Suggested changes that yield improved fan noise predictions but preserve the Heidmann model structure are identified and described. These changes are based on the sets of engine data mentioned, as well as some CFM56 engine data that was used to expand the combination tone noise database. It should be noted that the recommended changes are based on an analysis of engines that are limited to single stage fans with design tip relative Mach numbers greater than one.

Exploring Advanced Technology Gas Turbine Engine Design and Performance for the Large Civil Tiltrotor (LCTR)

NASA Technical Reports Server (NTRS)

Snyder, Christopher A.

2014-01-01

A Large Civil Tiltrotor (LCTR) conceptual design was developed as part of the NASA Heavy Lift Rotorcraft Systems Investigation in order to establish a consistent basis for evaluating the benefits of advanced technology for large tiltrotors. The concept has since evolved into the second-generation LCTR2, designed to carry 90 passengers for 1,000 nautical miles at 300 knots, with vertical takeoff and landing capability. This paper explores gas turbine component performance and cycle parameters to quantify performance gains possible for additional improvements in component and material performance beyond those identified in previous LCTR2 propulsion studies and to identify additional research areas. The vehicle-level characteristics from this advanced technology generation 2 propulsion architecture will help set performance levels as additional propulsion and power systems are conceived to meet ever-increasing requirements for mobility and comfort, while reducing energy use, cost, noise and emissions. The Large Civil Tiltrotor vehicle and mission will be discussed as a starting point for this effort. A few, relevant engine and component technology studies, including previous LCTR2 engine study results will be summarized to help orient the reader on gas turbine engine architecture, performance and limitations. Study assumptions and methodology used to explore engine design and performance, as well as assess vehicle sizing and mission performance will then be discussed. Individual performance for present and advanced engines, as well as engine performance effects on overall vehicle size and mission fuel usage, will be given. All results will be summarized to facilitate understanding the importance and interaction of various component and system performance on overall vehicle characteristics.

Probabilistic structural analysis methods for improving Space Shuttle engine reliability

NASA Technical Reports Server (NTRS)

Boyce, L.

1989-01-01

Probabilistic structural analysis methods are particularly useful in the design and analysis of critical structural components and systems that operate in very severe and uncertain environments. These methods have recently found application in space propulsion systems to improve the structural reliability of Space Shuttle Main Engine (SSME) components. A computer program, NESSUS, based on a deterministic finite-element program and a method of probabilistic analysis (fast probability integration) provides probabilistic structural analysis for selected SSME components. While computationally efficient, it considers both correlated and nonnormal random variables as well as an implicit functional relationship between independent and dependent variables. The program is used to determine the response of a nickel-based superalloy SSME turbopump blade. Results include blade tip displacement statistics due to the variability in blade thickness, modulus of elasticity, Poisson's ratio or density. Modulus of elasticity significantly contributed to blade tip variability while Poisson's ratio did not. Thus, a rational method for choosing parameters to be modeled as random is provided.

2nd Generation RLV Risk Reduction Definition Program: Pratt & Whitney Propulsion Risk Reduction Requirements Program (TA-3 & TA-4)

NASA Technical Reports Server (NTRS)

Matlock, Steve

2001-01-01

This is the final report and addresses all of the work performed on this program. Specifically, it covers vehicle architecture background, definition of six baseline engine cycles, reliability baseline (space shuttle main engine QRAS), and component level reliability/performance/cost for the six baseline cycles, and selection of 3 cycles for further study. This report further addresses technology improvement selection and component level reliability/performance/cost for the three cycles selected for further study, as well as risk reduction plans, and recommendation for future studies.

Enabling High Efficiency Ethanol Engines

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

Szybist, J.; Confer, K.

2011-03-01

Delphi Automotive Systems and ORNL established this CRADA to explore the potential to improve the energy efficiency of spark-ignited engines operating on ethanol-gasoline blends. By taking advantage of the fuel properties of ethanol, such as high compression ratio and high latent heat of vaporization, it is possible to increase efficiency with ethanol blends. Increasing the efficiency with ethanol-containing blends aims to remove a market barrier of reduced fuel economy with E85 fuel blends, which is currently about 30% lower than with petroleum-derived gasoline. The same or higher engine efficiency is achieved with E85, and the reduction in fuel economy ismore » due to the lower energy density of E85. By making ethanol-blends more efficient, the fuel economy gap between gasoline and E85 can be reduced. In the partnership between Delphi and ORNL, each organization brought a unique and complementary set of skills to the project. Delphi has extensive knowledge and experience in powertrain components and subsystems as well as overcoming real-world implementation barriers. ORNL has extensive knowledge and expertise in non-traditional fuels and improving engine system efficiency for the next generation of internal combustion engines. Partnering to combine these knowledge bases was essential towards making progress to reducing the fuel economy gap between gasoline and E85. ORNL and Delphi maintained strong collaboration throughout the project. Meetings were held regularly, usually on a bi-weekly basis, with additional reports, presentations, and meetings as necessary to maintain progress. Delphi provided substantial hardware support to the project by providing components for the single-cylinder engine experiments, engineering support for hardware modifications, guidance for operational strategies on engine research, and hardware support by providing a flexible multi-cylinder engine to be used for optimizing engine efficiency with ethanol-containing fuels.« less

Phase of Photothermal Emission Analysis as a Diagnostic Tool for Thermal Barrier Coatings on Serviceable Engine Components

NASA Astrophysics Data System (ADS)

Kakuda, Tyler

Power generation and aircraft companies are continuously improving the efficiency of gas turbines to meet economic and environmental goals. The trend towards higher efficiency has been achieved in part by raising the operating temperature of engines. At elevated temperatures, engine components are subject to many forms of degradation including oxidation, creep deformation and thermal cycle fatigue. To minimize these harmful effects, ceramic thermal barrier coatings (TBCs) are routinely used to insulate metal components from excessive heat loads. Efforts to make realistic performance assessments of current and candidate coating materials has led to a diverse battery of creative measurement techniques. While it is unrealistic to envision a single measurement that would provide all conceivable information about the TBC, it is arguable that the capability for the single most important measurement is still lacking. A quantitative and nondestructive measurement of the thermal protection offered by a coating is not currently among the measurements one can employ on a serviceable engine part (or even many experimental specimens). In this contribution, phase of photothermal emission analysis (PopTea) is presented as a viable thermal property measurement for serviceable engine components. As it will be shown, PopTea has the versatility to make measurements on gas turbine parts in situ, with the goal of monitoring TBCs over the lifetime of the engine. The main challenges toward this goal are dealing with changes that occur to the TBC during service. Several of the main degradations seen on engine equipment include: aging, surface contamination and infiltration of foreign deposits. Measuring coatings under these conditions, is the impetus of this work. Furthermore, it is demonstrated that PopTea can be used on real engine equipment with measurements made on an actual turbine blade.

Bell P–63A King Cobra at the Aircraft Engine Research Laboratory

NASA Image and Video Library

1944-01-21

The Army Air Forces lent the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory a Bell P–63A King Cobra in October 1943 to complement the lab's extensive efforts to improve the Allison V–1710 engine. The V–1710-powered P–63A was a single-seat fighter that could reach speeds of 410 miles per hour and an altitude of 43,000 feet. The fighter, first produced in 1942, was an improvement on Bell’s P–39, but persistent performance problems at high altitudes prevented its acceptance by the Air Corps. Instead many of the P–63s were transferred to the Soviet Union. Almost every test facility at the NACA’s engine lab was used to study the Allison V–1710 engine and its supercharger during World War II. Researchers were able to improve the efficiency, capacity and pressure ratio of the supercharger. They found that improved cooling significantly reduced engine knock in the fuel. Once the researchers were satisfied with their improvements, the new supercharger and cooling components were installed on the P–63A. The Flight Research Division first established the aircraft’s normal flight performance parameters such as speed at various altitudes, rate of climb, and peak altitude. Ensuing flights established the performance parameters of the new configuration in order to determine the improved performance. The program increased V–1710’s horsepower from 1650 to 2250.

From Brainstorming to C-Sketch to Principles of Historical Innovators: Ideation Techniques to Enhance Student Creativity

ERIC Educational Resources Information Center

White, Christina; Wood, Kristin; Jensen, Dan

2012-01-01

The heart and soul of engineering is innovation and our ability to improve the human condition through design. To enrich engineering education, it is critical that we advance our teaching in innovation and design processes. This research focuses on the ideation component of innovation through the investigation of a suite of concept generation…

Impact-Resistant Ceramic Coating

NASA Technical Reports Server (NTRS)

Wheeler, W. H.; Creedon, J. F.; Izu, Y. D.

1986-01-01

Refractory fibers more than double strength of coating. Impact strengths of ceramic coatings increase with increasing whisker content. Silicon carbide whiskers clearly produce largest increase, and improvement grows even more with high-temperature sintering. Coating also improves thermal and mechanical properties of electromagnetic components, mirrors, furnace linings, and ceramic parts of advanced internal-combustion engines.

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.

Genetically Engineered Materials for Biofuels Production

NASA Astrophysics Data System (ADS)

Raab, Michael

2012-02-01

Agrivida, Inc., is an agricultural biotechnology company developing industrial crop feedstocks for the fuel and chemical industries. Agrivida's crops have improved processing traits that enable efficient, low cost conversion of the crops' cellulosic components into fermentable sugars. Currently, pretreatment and enzymatic conversion of the major cell wall components, cellulose and hemicellulose, into fermentable sugars is the most expensive processing step that prevents widespread adoption of biomass in biofuels processes. To lower production costs we are consolidating pretreatment and enzyme production within the crop. In this strategy, transgenic plants express engineered cell wall degrading enzymes in an inactive form, which can be reactivated after harvest. We have engineered protein elements that disrupt enzyme activity during normal plant growth. Upon exposure to specific processing conditions, the engineered enzymes are converted into their active forms. This mechanism significantly lowers pretreatment costs and enzyme loadings (>75% reduction) below those currently available to the industry.

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.

Engine System Model Development for Nuclear Thermal Propulsion

NASA Technical Reports Server (NTRS)

Nelson, Karl W.; Simpson, Steven P.

2006-01-01

In order to design, analyze, and evaluate conceptual Nuclear Thermal Propulsion (NTP) engine systems, an improved NTP design and analysis tool has been developed. The NTP tool utilizes the Rocket Engine Transient Simulation (ROCETS) system tool and many of the routines from the Enabler reactor model found in Nuclear Engine System Simulation (NESS). Improved non-nuclear component models and an external shield model were added to the tool. With the addition of a nearly complete system reliability model, the tool will provide performance, sizing, and reliability data for NERVA-Derived NTP engine systems. A new detailed reactor model is also being developed and will replace Enabler. The new model will allow more flexibility in reactor geometry and include detailed thermal hydraulics and neutronics models. A description of the reactor, component, and reliability models is provided. Another key feature of the modeling process is the use of comprehensive spreadsheets for each engine case. The spreadsheets include individual worksheets for each subsystem with data, plots, and scaled figures, making the output very useful to each engineering discipline. Sample performance and sizing results with the Enabler reactor model are provided including sensitivities. Before selecting an engine design, all figures of merit must be considered including the overall impacts on the vehicle and mission. Evaluations based on key figures of merit of these results and results with the new reactor model will be performed. The impacts of clustering and external shielding will also be addressed. Over time, the reactor model will be upgraded to design and analyze other NTP concepts with CERMET and carbide fuel cores.

Impact design methods for ceramic components in gas turbine engines

NASA Technical Reports Server (NTRS)

Song, J.; Cuccio, J.; Kington, H.

1991-01-01

Methods currently under development to design ceramic turbine components with improved impact resistance are presented. Two different modes of impact damage are identified and characterized, i.e., structural damage and local damage. The entire computation is incorporated into the EPIC computer code. Model capability is demonstrated by simulating instrumented plate impact and particle impact tests.

Improving Engine Efficiency Through Core Developments

NASA Technical Reports Server (NTRS)

Heidmann, James D.

2011-01-01

The NASA Environmentally Responsible Aviation (ERA) Project and Fundamental Aeronautics Projects are supporting compressor and turbine research with the goal of reducing aircraft engine fuel burn and greenhouse gas emissions. The primary goals of this work are to increase aircraft propulsion system fuel efficiency for a given mission by increasing the overall pressure ratio (OPR) of the engine while maintaining or improving aerodynamic efficiency of these components. An additional area of work involves reducing the amount of cooling air required to cool the turbine blades while increasing the turbine inlet temperature. This is complicated by the fact that the cooling air is becoming hotter due to the increases in OPR. Various methods are being investigated to achieve these goals, ranging from improved compressor three-dimensional blade designs to improved turbine cooling hole shapes and methods. Finally, a complementary effort in improving the accuracy, range, and speed of computational fluid mechanics (CFD) methods is proceeding to better capture the physical mechanisms underlying all these problems, for the purpose of improving understanding and future designs.

Integrating enzyme immobilization and protein engineering: An alternative path for the development of novel and improved industrial biocatalysts.

PubMed

Bernal, Claudia; Rodríguez, Karen; Martínez, Ronny

2018-06-09

Enzyme immobilization often achieves reusable biocatalysts with improved operational stability and solvent resistance. However, these modifications are generally associated with a decrease in activity or detrimental modifications in catalytic properties. On the other hand, protein engineering aims to generate enzymes with increased performance at specific conditions by means of genetic manipulation, directed evolution and rational design. However, the achieved biocatalysts are generally generated as soluble enzymes, -thus not reusable- and their performance under real operational conditions is uncertain. Combined protein engineering and enzyme immobilization approaches have been employed as parallel or consecutive strategies for improving an enzyme of interest. Recent reports show efforts on simultaneously improving both enzymatic and immobilization components through genetic modification of enzymes and optimizing binding chemistry for site-specific and oriented immobilization. Nonetheless, enzyme engineering and immobilization are usually performed as separate workflows to achieve improved biocatalysts. In this review, we summarize and discuss recent research aiming to integrate enzyme immobilization and protein engineering and propose strategies to further converge protein engineering and enzyme immobilization efforts into a novel "immobilized biocatalyst engineering" research field. We believe that through the integration of both enzyme engineering and enzyme immobilization strategies, novel biocatalysts can be obtained, not only as the sum of independently improved intrinsic and operational properties of enzymes, but ultimately tailored specifically for increased performance as immobilized biocatalysts, potentially paving the way for a qualitative jump in the development of efficient, stable biocatalysts with greater real-world potential in challenging bioprocess applications. Copyright © 2018. Published by Elsevier Inc.

Method for Making a Carbon-Carbon Cylinder Block

NASA Technical Reports Server (NTRS)

Ransone, Phillip O. (Inventor)

1997-01-01

A method for making a lightweight cylinder block composed of carbon-carbon is disclosed. The use of carbon-carbon over conventional materials. such as cast iron or aluminum, reduces the weight of the cylinder block and improves thermal efficiency of the internal combustion reciprocating engine. Due to the negligible coefficient of thermal expansion and unique strength at elevated temperatures of carbon-carbon, the piston-to-cylinder wall clearance can be small, especially when the carbon-carbon cylinder block is used in conjunction with a carbon-carbon piston. Use of the carbon-carbon cylinder block has the effect of reducing the weight of other reciprocating engine components allowing the piston to run at higher speeds and improving specific engine performance.

Combination probes for stagnation pressure and temperature measurements in gas turbine engines

NASA Astrophysics Data System (ADS)

Bonham, C.; Thorpe, S. J.; Erlund, M. N.; Stevenson, R. J.

2018-01-01

During gas turbine engine testing, steady-state gas-path stagnation pressures and temperatures are measured in order to calculate the efficiencies of the main components of turbomachinery. These measurements are acquired using fixed intrusive probes, which are installed at the inlet and outlet of each component at discrete point locations across the gas-path. The overall uncertainty in calculated component efficiency is sensitive to the accuracy of discrete point pressures and temperatures, as well as the spatial sampling across the gas-path. Both of these aspects of the measurement system must be considered if more accurate component efficiencies are to be determined. High accuracy has become increasingly important as engine manufacturers have begun to pursue small gains in component performance, which require efficiencies to be resolved to within less than  ± 1% . This article reports on three new probe designs that have been developed in a response to this demand. The probes adopt a compact combination arrangement that facilitates up to twice the spatial coverage compared to individual stagnation pressure and temperature probes. The probes also utilise novel temperature sensors and high recovery factor shield designs that facilitate improvements in point measurement accuracy compared to standard Kiel probes used in engine testing. These changes allow efficiencies to be resolved within  ± 1% over a wider range of conditions than is currently achievable with Kiel probes.

Intelligent Engine Systems

NASA Technical Reports Server (NTRS)

Xie, Ming

2008-01-01

A high bypass jet engine fan case represents one of the largest, heaviest single components in an engine. In addition to supporting the inlet and providing the fan flowpath, the most critical function is the containment of a failed fan blade. In this development program, a lightweight, low-cost composite containment case with diagnostic capabilities was developed, fabricated, and tested. The fan case design, containment methods, and diagnostic concepts evaluated in the initial Propulsion 21 program were improved and scaled up to a full case design.

Borescope Inspection Management for Engine

NASA Astrophysics Data System (ADS)

Zhongda, Yuan

2018-03-01

In this paper, we try to explain the problems need to be improved from the two perspectives of maintenance program management and maintenance human risk control. On the basis of optimization analysis of borescope inspection maintenance scheme, the defect characteristics and expansion rules of engine heat terminal components are summarized, and some optimization measures are introduced. This paper analyses human risk problem of engine hole from the aspects of qualification management, training requirements and perfection of system, and puts forward some suggestions on management.

The engine fuel system fault analysis

NASA Astrophysics Data System (ADS)

Zhang, Yong; Song, Hanqiang; Yang, Changsheng; Zhao, Wei

2017-05-01

For improving the reliability of the engine fuel system, the typical fault factor of the engine fuel system was analyzed from the point view of structure and functional. The fault character was gotten by building the fuel system fault tree. According the utilizing of fault mode effect analysis method (FMEA), several factors of key component fuel regulator was obtained, which include the fault mode, the fault cause, and the fault influences. All of this made foundation for next development of fault diagnosis system.

Lewis Researcher in the Materials and Stresses Building

NASA Image and Video Library

1952-12-21

A materials researcher at the NACA’s Lewis Flight Propulsion Laboratory examines a surface crack detection apparatus in the Materials and Stresses Building during December 1952. Materials research was an important aspect of propulsion technology. Advanced engine systems relied upon alloys, and later composites, that were strong, lightweight, and impervious to high temperatures. Jet engines which became increasingly popular in the late 1940s, produced much higher temperatures than piston engines. These higher temperatures stressed engine components, particularly turbines. Although Lewis materials research began during World War II, the Materials and Thermodynamics Division was not created until 1949. Its primary laboratories were located in the Materials and Stresses Building. The group sought to create new, improved materials and to improve engine design through increased understanding of materials. The Lewis materials researchers of the 1950s made contributions to nickel-aluminum alloys, cermet blades, metal matrix composites, oxide dispersion strengthened superalloys, and universal slopes.

Research and development of improved geothermal well logging techniques, tools and components (current projects, goals and status). Final report

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

Lamers, M.D.

One of the key needs in the advancement of geothermal energy is availability of adequate subsurface measurements to aid the reservoir engineer in the development and operation of geothermal wells. Some current projects being sponsored by the U. S. Department of Energy's Division of Geothermal Energy pertaining to the development of improved well logging techniques, tools and components are described. An attempt is made to show how these projects contribute to improvement of geothermal logging technology in forming key elements of the overall program goals.

Improved Slip Casting Of Ceramic Models

NASA Technical Reports Server (NTRS)

Buck, Gregory M.; Vasquez, Peter; Hicks, Lana P.

1994-01-01

Improved technique of investment slip casting developed for making precise ceramic wind-tunnel models. Needed in wind-tunnel experiments to verify predictions of aerothermodynamical computer codes. Ceramic materials used because of their low heat conductivities and ability to survive high temperatures. Present improved slip-casting technique enables casting of highly detailed models from aqueous or nonaqueous solutions. Wet shell molds peeled off models to ensure precise and undamaged details. Used at NASA Langley Research Center to form superconducting ceramic components from nonaqueous slip solutions. Technique has many more applications when ceramic materials developed further for such high-strength/ temperature components as engine parts.

Small gas turbine engine technology

NASA Technical Reports Server (NTRS)

Niedzwiecki, Richard W.; Meitner, Peter L.

1988-01-01

Performance of small gas turbine engines in the 250 to 1,000 horsepower size range is significantly lower than that of large engines. Engines of this size are typically used in rotorcraft, commutercraft, general aviation, and cruise missile applications. Principal reasons for the lower efficiencies of a smaller engine are well known: component efficients are lower by as much as 8 to 10 percentage points because of size effects. Small engines are designed for lower cycle pressures and temperatures because of smaller blading and cooling limitations. The highly developed analytical and manufacturing techniques evolved for large engines are not directly transferrable to small engines. Thus, it was recognized that a focused effort addressing technologies for small engies was needed and could significantly impact their performance. Recently, in-house and contract studies were undertaken at the NASA Lewis Research Center to identify advanced engine cycle and component requirements for substantial performance improvement of small gas turbines for projected year 2000 applications. The results of both in-house research and contract studies are presented. In summary, projected fuel savings of 22 to 42 percent could be obtained. Accompanying direct operating cost reductions of 11 to 17 percent, depending on fuel cost, were also estimated. High payoff technologies are identified for all engine applications, and recent results of experimental research to evolve the high payoff technologies are described.

Performance seeking control (PSC) for the F-15 highly integrated digital electronic control (HIDEC) aircraft

NASA Technical Reports Server (NTRS)

Orme, John S.

1995-01-01

The performance seeking control algorithm optimizes total propulsion system performance. This adaptive, model-based optimization algorithm has been successfully flight demonstrated on two engines with differing levels of degradation. Models of the engine, nozzle, and inlet produce reliable, accurate estimates of engine performance. But, because of an observability problem, component levels of degradation cannot be accurately determined. Depending on engine-specific operating characteristics PSC achieves various levels performance improvement. For example, engines with more deterioration typically operate at higher turbine temperatures than less deteriorated engines. Thus when the PSC maximum thrust mode is applied, for example, there will be less temperature margin available to be traded for increasing thrust.

Development of a Kevlar/PMR-15 reduced drag DC-9 nacelle fairing

NASA Technical Reports Server (NTRS)

Kawai, R. T.; Hrach, F. J.

1980-01-01

The paper describes an advanced composite fairing designed to reduce drag on DC-9 nacelles as a part of the NASA Engine Component Improvement Program. This fairing is the aft enclosure for the thrust reverser actuator system on JT8D engine nacelles and is subjected to a 500 F exhaust flow during the reverse thrust. A reduced-drag configuration was developed by using in-flight tuft surveys for flow visualization in order to identify areas with low-quality flow, and then modifying the aerodynamic lines to improve the flow. A fabrication method for molding the part in an autoclave was developed; this material system is suitable for 500 F. The resultant composite fairing reduces the overall aircraft drag 1% with a weight reduction of 40% when compared with a metal component.

Cascade Optimization for Aircraft Engines With Regression and Neural Network Analysis - Approximators

NASA Technical Reports Server (NTRS)

Patnaik, Surya N.; Guptill, James D.; Hopkins, Dale A.; Lavelle, Thomas M.

2000-01-01

The NASA Engine Performance Program (NEPP) can configure and analyze almost any type of gas turbine engine that can be generated through the interconnection of a set of standard physical components. In addition, the code can optimize engine performance by changing adjustable variables under a set of constraints. However, for engine cycle problems at certain operating points, the NEPP code can encounter difficulties: nonconvergence in the currently implemented Powell's optimization algorithm and deficiencies in the Newton-Raphson solver during engine balancing. A project was undertaken to correct these deficiencies. Nonconvergence was avoided through a cascade optimization strategy, and deficiencies associated with engine balancing were eliminated through neural network and linear regression methods. An approximation-interspersed cascade strategy was used to optimize the engine's operation over its flight envelope. Replacement of Powell's algorithm by the cascade strategy improved the optimization segment of the NEPP code. The performance of the linear regression and neural network methods as alternative engine analyzers was found to be satisfactory. This report considers two examples-a supersonic mixed-flow turbofan engine and a subsonic waverotor-topped engine-to illustrate the results, and it discusses insights gained from the improved version of the NEPP code.

Propulsion System Advances that Enable a Reusable Liquid Fly Back Booster (LFBB)

NASA Technical Reports Server (NTRS)

Keith, Edward L.; Rothschild, William J.

1998-01-01

This paper provides an overview of the booster propulsion system for the Liquid Fly Back Booster (LFBB). This includes, system requirements, design approach, concept of operations, reliability, safety and cost assumptions. The paper summarizes the findings of the Boeing propulsion team that has been studying the LFBB feasibility as a booster replacement for the Space Shuttle. This paper will discuss recent advances including a new generation of kerosene and oxygen rich pre-burner staged combustion cycle main rocket engines. The engine reliability and safety is expected to be much higher than current standards by adding extra operating margins into the design and normally operating the engines at 75% of engine rated power. This allows for engine out capability. The new generation of main engines operates at significantly higher chamber pressure than the prior generation of gas generator cycle engines. The oxygen rich pre-burner engine cycle, unlike the fuel rich gas generator cycle, results in internally self-cleaning firings which facilitates reusability. Maintenance is further enhanced with integrated health monitoring to improve safety and turn-around efficiency. The maintainability of the LFBB LOX / kerosene engines is being improved by designing the vehicle/engine interfaces for easy access to key engine components.

Propulsion system advances that enable a reusable Liquid Fly Back Booster (LFBB)

NASA Technical Reports Server (NTRS)

Keith, E. L.; Rothschild, W. J.

1998-01-01

This paper provides an overview of the booster propulsion system for the Liquid Fly Back Booster (LFBB). This includes, system requirements, design approach, concept of operations, reliability, safety and cost assumptions. The paper summarizes the findings of the Boeing propulsion team that has been studying the LFBB feasibility as a booster replacement for the Space Shuttle. This paper will discuss recent advances including a new generation of kerosene and oxygen rich pre-burner staged combustion cycle main rocket engines. The engine reliability and safety is expected to be much higher than current standards by adding extra operating margins into the design and normally operating the engines at 75% of engine rated power. This allows for engine out capability. The new generation of main engines operates at significantly higher chamber pressure than the prior generation of gas generator cycle engines. The oxygen rich pre-burner engine cycle, unlike the fuel rich gas generator cycle, results in internally self-cleaning firings which facilitates reusability. Maintenance is further enhanced with integrated health monitoring to improve safety and turn-around efficiency. The maintainability of the LFBB LOX/kerosene engines is being improved by designing the vehicle/engine interfaces for easy access to key engine components.

Analysis of Performance of Jet Engine from Characteristics of Components II : Interaction of Components as Determined from Engine Operation

NASA Technical Reports Server (NTRS)

Goldstein, Arthur W; Alpert, Sumner; Beede, William; Kovach, Karl

1949-01-01

In order to understand the operation and the interaction of jet-engine components during engine operation and to determine how component characteristics may be used to compute engine performance, a method to analyze and to estimate performance of such engines was devised and applied to the study of the characteristics of a research turbojet engine built for this investigation. An attempt was made to correlate turbine performance obtained from engine experiments with that obtained by the simpler procedure of separately calibrating the turbine with cold air as a driving fluid in order to investigate the applicability of component calibration. The system of analysis was also applied to prediction of the engine and component performance with assumed modifications of the burner and bearing characteristics, to prediction of component and engine operation during engine acceleration, and to estimates of the performance of the engine and the components when the exhaust gas was used to drive a power turbine.

Evaluation of Thermal Barrier and PS-200 Self-Lubricating Coatings in an Air-Cooled Rotary Engine

NASA Technical Reports Server (NTRS)

Moller, Paul S.

1995-01-01

This project provides an evaluation of the feasibility and desirability of applying a thermal barrier coating overlaid with a wear coating on the internal surfaces of the combustion area of rotary engines. Many experiments were conducted with different combinations of coatings applied to engine components of aluminum, iron and titanium, and the engines were run on a well-instrumented test stand. Significant improvements in specific fuel consumption were achieved and the wear coating, PS-200, which was invented at NASA's Lewis Research Center, held up well under severe test conditions.

[Tissue engineering applied to the trachea as a graft].

PubMed

Barrera-Ramírez, Elisa; Rico-Escobar, Edna; Garrido-Cardona, Rubén E

2016-01-01

Tissue engineering offers, through new technologies, an ex vivo generation of organs and functional tissues as grafts for transplants, for the improvement and substitution of biological functions, with an absence of immunological response. The treatment of extended tracheal lesions is a substitution of the affected segment; nevertheless, the allogeneic transplant has failed and the use of synthetic materials has not had good results. New tissue engineering technology is being developed to offer a tracheal graft for a posterior implantation. The purpose of this article is to review all the methods and components used by the engineering of tissue for tracheal grafts.

Multiple Integrated Navigation Sensors for Improved Occupancy Grid FastSLAM

DTIC Science & Technology

2011-03-01

to the Faculty Department of Electrical and Computer Engineering Graduate School of Engineering and Management Air Force Institute of Technology Air...autonomous vehicle exploration with applications to search and rescue. To current knowledge , this research presents the first SLAM solution to...solution is a key component of an autonomous vehicle, especially one whose mission involves gaining knowledge of unknown areas. It provides the ability

Thermal modeling in an engine cooling system to control coolant flow for fuel consumption improvement

NASA Astrophysics Data System (ADS)

Park, Sangki; Woo, Seungchul; Kim, Minho; Lee, Kihyung

2017-04-01

The design and evaluation of engine cooling and lubrication systems is generally based on real vehicle tests. Our goal here was to establish an engine heat balance model based on mathematical and interpretive analysis of each element of a passenger diesel engine cooling system using a 1-D numerical model. The purpose of this model is to determine ways of optimizing the cooling and lubrication components of an engine and then to apply these methods to actual cooling and lubrication systems of engines that will be developed in the future. Our model was operated under the New European Driving Cycle (NEDC) mode conditions, which represent the fuel economy evaluation mode in Europe. The flow rate of the cooling system was controlled using a control valve. Our results showed that the fuel efficiency was improved by as much as 1.23 %, cooling loss by 1.35 %, and friction loss by 2.21 % throughout NEDC modes by modification of control conditions.

System Engineering for J-2X Development: The Simpler, the Better

NASA Technical Reports Server (NTRS)

Kelly, William M.; Greasley, Paul; Greene, William D.; Ackerman, Peter

2008-01-01

The Ares I and Ares V Vehicles will utilize the J-2X rocket engine developed for NASA by the Pratt and Whitney Rocketdyne Company (PWR) as the upper stage engine (USE). The J-2X is an improved higher power version of the original J-2 engine used for Apollo. System Engineering (SE) facilitates direct and open discussions of issues and problems. This simple idea is often overlooked in large, complex engineering development programs. Definition and distribution of requirements from the engine level to the component level is controlled by Allocation Reports which breaks down numerical design objectives (weight, reliability, etc.) into quanta goals for each component area. Linked databases of design and verification requirements help eliminate redundancy and potential mistakes inherent in separated systems. Another tool, the Architecture Design Description (ADD), is used to control J-2X system architecture and effectively communicate configuration changes to those involved in the design process. But the proof of an effective process is in successful program accomplishment. SE is the methodology being used to meet the challenge of completing J-2X engine certification 2 years ahead of any engine program ever developed at PWR. This paper describes the simple, better SE tools and techniques used to achieve this success.

A Review of Engine Seal Performance and Requirements for Current and Future Army Engine Platforms

NASA Technical Reports Server (NTRS)

Delgado, Irebert R.; Proctor, Margaret P.

2008-01-01

Sand ingestion continues to impact combat ground and air vehicles in military operations in the Middle East. The T-700 engine used in Apache and Blackhawk helicopters has been subjected to increased overhauls due to sand and dust ingestion during desert operations. Engine component wear includes compressor and turbine blades/vanes resulting in decreased engine power and efficiency. Engine labyrinth seals have also been subjected to sand and dust erosion resulting in tooth tip wear, increased clearances, and loss in efficiency. For the current investigation, a brief overview is given of the history of the T-700 engine development with respect to sand and dust ingestion requirements. The operational condition of labyrinth seals taken out of service from 4 different locations of the T-700 engine during engine overhauls are examined. Collaborative efforts between the Army and NASA to improve turbine engine seal leakage and life capability are currently focused on noncontacting, low leakage, compliant designs. These new concepts should be evaluated for their tolerance to sand laden air. Future R&D efforts to improve seal erosion resistance and operation in desert environments are recommended

Procurement engineering - the productivity factor

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

Bargerstock, S.B.

1993-01-01

The industry is several years on the road to implementation of the Nuclear Management and Resources Council (NUMARC) initiatives on commercial-grade item dedication and procurement. Utilities have taken several approaches to involve engineering in the procurement process. A common result for the approaches is the additional operations and maintenance (O M) cost imposed by the added resource requirements. Procurement engineering productivity is a key element in controlling this business area. Experience shows that 400 to 500% improvements in productivity are possible with a 2-yr period. Improving the productivity of the procurement engineering function is important in today's competitive utility environment.more » Procurement engineering typically involves four distinct technical evaluation responsibilities along with several administrative areas. Technical evaluations include the functionally based safety classification of replacement components and parts (lacking a master parts list), the determination of dedication requirements for safety-related commercial-grade items, the preparation of a procurement specification to maintain the licensed design bases, and the equivalency evaluation of alternate items not requiring the design-change process. Administrative duties include obtaining technical review of vendor-supplied documentation, identifying obsolete parts and components, resolving material nonconformances, initiating the design-change process for replacement items (as needed), and providing technical support to O M. Although most utilities may not perform or require all the noted activities, a large percentage will apply to each utility station.« less

Systems metabolic engineering in an industrial setting.

PubMed

Sagt, Cees M J

2013-03-01

Systems metabolic engineering is based on systems biology, synthetic biology, and evolutionary engineering and is now also applied in industry. Industrial use of systems metabolic engineering focuses on strain and process optimization. Since ambitious yields, titers, productivities, and low costs are key in an industrial setting, the use of effective and robust methods in systems metabolic engineering is becoming very important. Major improvements in the field of proteomics and metabolomics have been crucial in the development of genome-wide approaches in strain and process development. This is accompanied by a rapid increase in DNA sequencing and synthesis capacity. These developments enable the use of systems metabolic engineering in an industrial setting. Industrial systems metabolic engineering can be defined as the combined use of genome-wide genomics, transcriptomics, proteomics, and metabolomics to modify strains or processes. This approach has become very common since the technology for generating large data sets of all levels of the cellular processes has developed quite fast into robust, reliable, and affordable methods. The main challenge and scope of this mini review is how to translate these large data sets in relevant biological leads which can be tested for strain or process improvements. Experimental setup, heterogeneity of the culture, and sample pretreatment are important issues which are easily underrated. In addition, the process of structuring, filtering, and visualization of data is important, but also, the availability of a genetic toolbox and equipment for medium/high-throughput fermentation is a key success factor. For an efficient bioprocess, all the different components in this process have to work together. Therefore, mutual tuning of these components is an important strategy.

The Navy/NASA Engine Program (NNEP89): A user's manual

NASA Technical Reports Server (NTRS)

Plencner, Robert M.; Snyder, Christopher A.

1991-01-01

An engine simulation computer code called NNEP89 was written to perform 1-D steady state thermodynamic analysis of turbine engine cycles. By using a very flexible method of input, a set of standard components are connected at execution time to simulate almost any turbine engine configuration that the user could imagine. The code was used to simulate a wide range of engine cycles from turboshafts and turboprops to air turborockets and supersonic cruise variable cycle engines. Off design performance is calculated through the use of component performance maps. A chemical equilibrium model is incorporated to adequately predict chemical dissociation as well as model virtually any fuel. NNEP89 is written in standard FORTRAN77 with clear structured programming and extensive internal documentation. The standard FORTRAN77 programming allows it to be installed onto most mainframe computers and workstations without modification. The NNEP89 code was derived from the Navy/NASA Engine program (NNEP). NNEP89 provides many improvements and enhancements to the original NNEP code and incorporates features which make it easier to use for the novice user. This is a comprehensive user's guide for the NNEP89 code.

Rotordynamic Characteristics of the HPOTP (High Pressure Oxygen Turbopump) of the SSME (Space Shuttle Main Engine)

NASA Technical Reports Server (NTRS)

Childs, D. W.

1984-01-01

Rotational stability of turbopump components in the space shuttle main engine was studied via analysis of component and structural dynamic models. Subsynchronous vibration caused unacceptable migration of the rotor/housing unit with unequal load sharing of the synchronous bearings that resulted in the failure of the High Pressure Oxygen Turbopump. Linear analysis shows that a shrouded inducer eliminates the second critical speed and the stability problem, a stiffened rotor improves the rotordynamic characteristics of the turbopump, and installing damper boost/impeller seals reduces bearing loads. Nonlinear analysis shows that by increasing the "dead band' clearances, a marked reduction in peak bearing loads occurs.

Physics-Based Design Tools for Lightweight Ceramic Composite Turbine Components with Durable Microstructures

NASA Technical Reports Server (NTRS)

DiCarlo, James A.

2011-01-01

Under the Supersonics Project of the NASA Fundamental Aeronautics Program, modeling and experimental efforts are underway to develop generic physics-based tools to better implement lightweight ceramic matrix composites into supersonic engine components and to assure sufficient durability for these components in the engine environment. These activities, which have a crosscutting aspect for other areas of the Fundamental Aero program, are focusing primarily on improving the multi-directional design strength and rupture strength of high-performance SiC/SiC composites by advanced fiber architecture design. This presentation discusses progress in tool development with particular focus on the use of 2.5D-woven architectures and state-of-the-art constituents for a generic un-cooled SiC/SiC low-pressure turbine blade.

Synthesis of three advanced biofuels from ionic liquid-pretreated switchgrass using engineered Escherichia coli

PubMed Central

Bokinsky, Gregory; Peralta-Yahya, Pamela P.; George, Anthe; Holmes, Bradley M.; Steen, Eric J.; Dietrich, Jeffrey; Soon Lee, Taek; Tullman-Ercek, Danielle; Voigt, Christopher A.; Simmons, Blake A.; Keasling, Jay D.

2011-01-01

One approach to reducing the costs of advanced biofuel production from cellulosic biomass is to engineer a single microorganism to both digest plant biomass and produce hydrocarbons that have the properties of petrochemical fuels. Such an organism would require pathways for hydrocarbon production and the capacity to secrete sufficient enzymes to efficiently hydrolyze cellulose and hemicellulose. To demonstrate how one might engineer and coordinate all of the necessary components for a biomass-degrading, hydrocarbon-producing microorganism, we engineered a microorganism naïve to both processes, Escherichia coli, to grow using both the cellulose and hemicellulose fractions of several types of plant biomass pretreated with ionic liquids. Our engineered strains express cellulase, xylanase, beta-glucosidase, and xylobiosidase enzymes under control of native E. coli promoters selected to optimize growth on model cellulosic and hemicellulosic substrates. Furthermore, our strains grow using either the cellulose or hemicellulose components of ionic liquid-pretreated biomass or on both components when combined as a coculture. Both cellulolytic and hemicellulolytic strains were further engineered with three biofuel synthesis pathways to demonstrate the production of fuel substitutes or precursors suitable for gasoline, diesel, and jet engines directly from ionic liquid-treated switchgrass without externally supplied hydrolase enzymes. This demonstration represents a major advance toward realizing a consolidated bioprocess. With improvements in both biofuel synthesis pathways and biomass digestion capabilities, our approach could provide an economical route to production of advanced biofuels. PMID:22123987

CCARES: A computer algorithm for the reliability analysis of laminated CMC components

NASA Technical Reports Server (NTRS)

Duffy, Stephen F.; Gyekenyesi, John P.

1993-01-01

Structural components produced from laminated CMC (ceramic matrix composite) materials are being considered for a broad range of aerospace applications that include various structural components for the national aerospace plane, the space shuttle main engine, and advanced gas turbines. Specifically, these applications include segmented engine liners, small missile engine turbine rotors, and exhaust nozzles. Use of these materials allows for improvements in fuel efficiency due to increased engine temperatures and pressures, which in turn generate more power and thrust. Furthermore, this class of materials offers significant potential for raising the thrust-to-weight ratio of gas turbine engines by tailoring directions of high specific reliability. The emerging composite systems, particularly those with silicon nitride or silicon carbide matrix, can compete with metals in many demanding applications. Laminated CMC prototypes have already demonstrated functional capabilities at temperatures approaching 1400 C, which is well beyond the operational limits of most metallic materials. Laminated CMC material systems have several mechanical characteristics which must be carefully considered in the design process. Test bed software programs are needed that incorporate stochastic design concepts that are user friendly, computationally efficient, and have flexible architectures that readily incorporate changes in design philosophy. The CCARES (Composite Ceramics Analysis and Reliability Evaluation of Structures) program is representative of an effort to fill this need. CCARES is a public domain computer algorithm, coupled to a general purpose finite element program, which predicts the fast fracture reliability of a structural component under multiaxial loading conditions.

Principal Component Analysis for Enhancement of Infrared Spectra Monitoring

NASA Astrophysics Data System (ADS)

Haney, Ricky Lance

The issue of air quality within the aircraft cabin is receiving increasing attention from both pilot and flight attendant unions. This is due to exposure events caused by poor air quality that in some cases may have contained toxic oil components due to bleed air that flows from outside the aircraft and then through the engines into the aircraft cabin. Significant short and long-term medical issues for aircraft crew have been attributed to exposure. The need for air quality monitoring is especially evident in the fact that currently within an aircraft there are no sensors to monitor the air quality and potentially harmful gas levels (detect-to-warn sensors), much less systems to monitor and purify the air (detect-to-treat sensors) within the aircraft cabin. The specific purpose of this research is to utilize a mathematical technique called principal component analysis (PCA) in conjunction with principal component regression (PCR) and proportionality constant calculations (PCC) to simplify complex, multi-component infrared (IR) spectra data sets into a reduced data set used for determination of the concentrations of the individual components. Use of PCA can significantly simplify data analysis as well as improve the ability to determine concentrations of individual target species in gas mixtures where significant band overlap occurs in the IR spectrum region. Application of this analytical numerical technique to IR spectrum analysis is important in improving performance of commercial sensors that airlines and aircraft manufacturers could potentially use in an aircraft cabin environment for multi-gas component monitoring. The approach of this research is two-fold, consisting of a PCA application to compare simulation and experimental results with the corresponding PCR and PCC to determine quantitatively the component concentrations within a mixture. The experimental data sets consist of both two and three component systems that could potentially be present as air contaminants in an aircraft cabin. In addition, experimental data sets are analyzed for a hydrogen peroxide (H2O2) aqueous solution mixture to determine H2O2 concentrations at various levels that could be produced during use of a vapor phase hydrogen peroxide (VPHP) decontamination system. After the PCA application to two and three component systems, the analysis technique is further expanded to include the monitoring of potential bleed air contaminants from engine oil combustion. Simulation data sets created from database spectra were utilized to predict gas components and concentrations in unknown engine oil samples at high temperatures as well as time-evolved gases from the heating of engine oils.

Engineering Concepts in Stem Cell Research.

PubMed

Narayanan, Karthikeyan; Mishra, Sachin; Singh, Satnam; Pei, Ming; Gulyas, Balazs; Padmanabhan, Parasuraman

2017-12-01

The field of regenerative medicine integrates advancements made in stem cells, molecular biology, engineering, and clinical methodologies. Stem cells serve as a fundamental ingredient for therapeutic application in regenerative medicine. Apart from stem cells, engineering concepts have equally contributed to the success of stem cell based applications in improving human health. The purpose of various engineering methodologies is to develop regenerative and preventive medicine to combat various diseases and deformities. Explosion of stem cell discoveries and their implementation in clinical setting warrants new engineering concepts and new biomaterials. Biomaterials, microfluidics, and nanotechnology are the major engineering concepts used for the implementation of stem cells in regenerative medicine. Many of these engineering technologies target the specific niche of the cell for better functional capability. Controlling the niche is the key for various developmental activities leading to organogenesis and tissue homeostasis. Biomimetic understanding not only helped to improve the design of the matrices or scaffolds by incorporating suitable biological and physical components, but also ultimately aided adoption of designs that helped these materials/devices have better function. Adoption of engineering concepts in stem cell research improved overall achievement, however, several important issues such as long-term effects with respect to systems biology needs to be addressed. Here, in this review the authors will highlight some interesting breakthroughs in stem cell biology that use engineering methodologies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The technology improvement and development of the new design-engineering principles of pilot bore directional drilling

NASA Astrophysics Data System (ADS)

Shadrina, A.; Saruev, L.; Vasenin, S.

2016-09-01

This paper addresses the effectiveness of impact energy use in pilot bore directional drilling at pipe driving. We establish and develop new design-engineering principles for this method. These principles are based on a drill string construction with a new nipple thread connection and a generator construction of strain waves transferred through the drill string. The experiment was conducted on a test bench. Strain measurement is used to estimate compression, tensile, shear and bending stresses in the drill string during the propagation of elastic waves. Finally, the main directions of pilot bore directional drilling improvement during pipe driving are determinated. The new engineering design, as components of the pilot bore directional drilling technology are presented.

Impact and promise of NASA aeropropulsion technology

NASA Technical Reports Server (NTRS)

Saunders, Neal T.; Bowditch, David N.

1987-01-01

The aeropropulsion industry in the United States has established an enviable record of leading the world in aeropropulsion for commercial and military aircraft. The NASA aeropropulsion propulsion program (primarily conducted through the Lewis Research Center) has significantly contributed to that success through research and technology advances and technology demonstrations such as the Refan, Engine Component Improvement, and the Energy Efficient Engine Programs. Some past NASA contributions to engines in current aircraft are reviewed, and technologies emerging from current research programs for the aircraft of the 1990's are described. Finally, current program thrusts toward improving propulsion systems in the 2000's for subsonic commercial aircraft and higher speed aircraft such as the High-Speed Civil Transport and the National Aerospace Plane (NASP) are discussed.

Polymeric Materials for Aerospace Power and Propulsion-NASA Glenn Overview

NASA Technical Reports Server (NTRS)

Meador, Michael A.

2008-01-01

Use of lightweight materials in aerospace power and propulsion components can lead to significant reductions in vehicle weight and improvements in performance and efficiency. Polymeric materials are well suited for many of these applications, but improvements in processability, durability and performance are required for their successful use in these components. Polymers Research at NASA Glenn is focused on utilizing a combination of traditional polymer science and engineering approaches and nanotechnology to develop new materials with enhanced processability, performance and durability. An overview of these efforts will be presented.

Coating Life Prediction

NASA Technical Reports Server (NTRS)

Nesbitt, J. A.; Gedwill, M. A.

1984-01-01

Hot-section gas-turbine components typically require some form of coating for oxidation and corrosion protection. Efficient use of coatings requires reliable and accurate predictions of the protective life of the coating. Currently engine inspections and component replacements are often made on a conservative basis. As a result, there is a constant need to improve and develop the life-prediction capability of metallic coatings for use in various service environments. The purpose of this present work is aimed at developing of an improved methodology for predicting metallic coating lives in an oxidizing environment and in a corrosive environment.

Combined Thermomechanical and Environmental Durability of Environmental Barrier Coating Systems on SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna

2016-01-01

Environmental barrier coatings (EBCs) and SiC/SiC ceramic matrix composites (CMCs) will play a crucial role in next generation turbine engines for hot-section component applications. The development of prime-reliant environmental barrier coatings is essential to the EBC-CMC system durability, ensuring the successful implementations of the high temperature and lightweight engine component technologies for engine applications.This paper will emphasize recent NASA environmental barrier coating and CMC developments for SiC/SiC turbine airfoil components, utilizing advanced coating compositions and processing methods. The emphasis has been particularly placed on thermomechanical and environment durability evaluations of EBC-CMC systems. We have also addressed the integration of the EBCs with advanced SiC/SiC CMCs, and studied the effects of combustion environments and Calcium-Magnesium-Alumino-Silicate (CMAS) deposits on the durability of the EBC-CMC systems under thermal gradient and mechanical loading conditions. Advanced environmental barrier coating systems, including multicomponent rare earth silicate EBCs and HfO2-Si based bond coats, will be discussed for the performance improvements to achieve better temperature capability and CMAS resistance for future engine operating conditions.

Combustor and Vane Features and Components Tested in a Gas Turbine Environment

NASA Technical Reports Server (NTRS)

Roinson, R. Craig; Verrilli, Michael J.

2003-01-01

The use of ceramic matrix composites (CMCs) as combustor liners and turbine vanes provides the potential of improving next-generation turbine engine performance, through lower emissions and higher cycle efficiency, relative to today s use of superalloy hot-section components. For example, the introduction of film-cooling air in metal combustor liners has led to higher levels of nitrogen oxide (NOx) emissions from the combustion process. An environmental barrier coated (EBC) siliconcarbide- fiber-reinforced silicon carbide matrix (SiC/SiC) composite is a new material system that can operate at higher temperatures, significantly reducing the film-cooling requirements and enabling lower NOx production. Evaluating components and subcomponents fabricated from these advanced CMCs under gas turbine conditions is paramount to demonstrating that the material system can perform as required in the complex thermal stress and environmentally aggressive engine environment. To date, only limited testing has been conducted on CMC combustor and turbine concepts and subelements of this type throughout the industry. As part of the Ultra-Efficient Engine Technology (UEET) Program, the High Pressure Burner Rig (HPBR) at the NASA Glenn Research Center was selected to demonstrate coupon, subcomponent feature, and component testing because it can economically provide the temperatures, pressures, velocities, and combustion gas compositions that closely simulate the engine environments. The results have proven the HPBR to be a highly versatile test rig amenable to multiple test specimen configurations essential to coupon and component testing.

Circulating heat exchangers for oscillating wave engines and refrigerators

DOEpatents

Swift, Gregory W.; Backhaus, Scott N.

2003-10-28

An oscillating-wave engine or refrigerator having a regenerator or a stack in which oscillating flow of a working gas occurs in a direction defined by an axis of a trunk of the engine or refrigerator, incorporates an improved heat exchanger. First and second connections branch from the trunk at locations along the axis in selected proximity to one end of the regenerator or stack, where the trunk extends in two directions from the locations of the connections. A circulating heat exchanger loop is connected to the first and second connections. At least one fluidic diode within the circulating heat exchanger loop produces a superimposed steady flow component and oscillating flow component of the working gas within the circulating heat exchanger loop. A local process fluid is in thermal contact with an outside portion of the circulating heat exchanger loop.

Rotary wave-ejector enhanced pulse detonation engine

NASA Astrophysics Data System (ADS)

Nalim, M. R.; Izzy, Z. A.; Akbari, P.

2012-01-01

The use of a non-steady ejector based on wave rotor technology is modeled for pulse detonation engine performance improvement and for compatibility with turbomachinery components in hybrid propulsion systems. The rotary wave ejector device integrates a pulse detonation process with an efficient momentum transfer process in specially shaped channels of a single wave-rotor component. In this paper, a quasi-one-dimensional numerical model is developed to help design the basic geometry and operating parameters of the device. The unsteady combustion and flow processes are simulated and compared with a baseline PDE without ejector enhancement. A preliminary performance assessment is presented for the wave ejector configuration, considering the effect of key geometric parameters, which are selected for high specific impulse. It is shown that the rotary wave ejector concept has significant potential for thrust augmentation relative to a basic pulse detonation engine.

14 CFR 33.53 - Engine system and component tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine system and component tests. 33.53... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.53 Engine system and component tests. (a) For those systems and components that cannot be adequately substantiated in accordance...

JT8D and JT9D jet engine performance improvement program. Task 1: Feasibility analysis

NASA Technical Reports Server (NTRS)

Gaffin, W. O.; Webb, D. E.

1979-01-01

JT8D and JT9D component performance improvement concepts which have a high probability of incorporation into production engines were identified and ranked. An evaluation method based on airline payback period was developed for the purpose of identifying the most promising concepts. The method used available test data and analytical models along with conceptual/preliminary designs to predict the performance improvements, weight, installation characteristics, cost for new production and retrofit, maintenance cost, and qualitative characteristics of candidate concepts. These results were used to arrive at the concept payback period, which is the time required for an airline to recover the investment cost of concept implementation.

Evaluation of Ceramic Matrix Composite Technology for Aircraft Turbine Engine Applications

NASA Technical Reports Server (NTRS)

Halbig, Michael C.; Jaskowiak, Martha H.; Kiser, James D.; Zhu, Dongming

2013-01-01

The goals of the NASA Environmentally Responsible Aviation (ERA) Project are to reduce the NO(x) emissions, fuel burn, and noise from turbine engines. In order to help meet these goals, commercially-produced ceramic matrix composite (CMC) components and environmental barrier coatings (EBCs) are being evaluated as parts and panels. The components include a CMC combustor liner, a CMC high pressure turbine vane, and a CMC exhaust nozzle as well as advanced EBCs that are tailored to the operating conditions of the CMC combustor and vane. The CMC combustor (w/EBC) could provide 2700 F temperature capability with less component cooling requirements to allow for more efficient combustion and reductions in NOx emissions. The CMC vane (w/EBC) will also have temperature capability up to 2700 F and allow for reduced fuel burn. The CMC mixer nozzle will offer reduced weight and improved mixing efficiency to provide reduced fuel burn. The main objectives are to evaluate the manufacturability of the complex-shaped components and to evaluate their performance under simulated engine operating conditions. Progress in CMC component fabrication, evaluation, and testing is presented in which the goal is to advance from the proof of concept validation (TRL 3) to a system/subsystem or prototype demonstration in a relevant environment (TRL 6).

Advanced supersonic propulsion study, phases 3 and 4. [variable cycle engines

NASA Technical Reports Server (NTRS)

Allan, R. D.; Joy, W.

1977-01-01

An evaluation of various advanced propulsion concepts for supersonic cruise aircraft resulted in the identification of the double-bypass variable cycle engine as the most promising concept. This engine design utilizes special variable geometry components and an annular exhaust nozzle to provide high take-off thrust and low jet noise. The engine also provides good performance at both supersonic cruise and subsonic cruise. Emission characteristics are excellent. The advanced technology double-bypass variable cycle engine offers an improvement in aircraft range performance relative to earlier supersonic jet engine designs and yet at a lower level of engine noise. Research and technology programs required in certain design areas for this engine concept to realize its potential benefits include refined parametric analysis of selected variable cycle engines, screening of additional unconventional concepts, and engine preliminary design studies. Required critical technology programs are summarized.

The CF6 jet engine performance improvement: New front mount

NASA Technical Reports Server (NTRS)

Fasching, W. A.

1979-01-01

The New Front Mount was evaluated in component tests including stress, deflection/distortion and fatigue tests. The test results demonstrated a performance improvement of 0.1% in cruise sfc, 16% in compressor stall margin and 10% in compressor stator angle margin. The New Front Mount hardware successfully completed 35,000 simulated flight cycles endurance testing.

Component research for future propulsion systems

NASA Technical Reports Server (NTRS)

Walker, C. L.; Weden, G. J.; Zuk, J.

1981-01-01

Factors affecting the helicopter market are reviewed. The trade-offs involving acquisition cost, mission reliability, and life cycle cost are reviewed, including civil and military aspects. The potential for advanced vehicle configurations with substantial improvements in energy efficiency, operating economics, and characteristics to satisfy the demands of the future market are identified. Advanced propulsion systems required to support these vehicle configurations are discussed, as well as the component technology for the engine systems. Considerations for selection of components in areas of economics and efficiency are presented.

Single shaft automotive gas turbine engine characterization test

NASA Technical Reports Server (NTRS)

Johnson, R. A.

1979-01-01

An automotive gas turbine incorporating a single stage centrifugal compressor and a single stage radial inflow turbine is described. Among the engine's features is the use of wide range variable geometry at the inlet guide vanes, the compressor diffuser vanes, and the turbine inlet vanes to achieve improved part load fuel economy. The engine was tested to determine its performance in both the variable geometry and equivalent fixed geometry modes. Testing was conducted without the originally designed recuperator. Test results were compared with the predicted performance of the nonrecuperative engine based on existing component rig test maps. Agreement between test results and the computer model was achieved.

Adaptation Method for Overall and Local Performances of Gas Turbine Engine Model

NASA Astrophysics Data System (ADS)

Kim, Sangjo; Kim, Kuisoon; Son, Changmin

2018-04-01

An adaptation method was proposed to improve the modeling accuracy of overall and local performances of gas turbine engine. The adaptation method was divided into two steps. First, the overall performance parameters such as engine thrust, thermal efficiency, and pressure ratio were adapted by calibrating compressor maps, and second, the local performance parameters such as temperature of component intersection and shaft speed were adjusted by additional adaptation factors. An optimization technique was used to find the correlation equation of adaptation factors for compressor performance maps. The multi-island genetic algorithm (MIGA) was employed in the present optimization. The correlations of local adaptation factors were generated based on the difference between the first adapted engine model and performance test data. The proposed adaptation method applied to a low-bypass ratio turbofan engine of 12,000 lb thrust. The gas turbine engine model was generated and validated based on the performance test data in the sea-level static condition. In flight condition at 20,000 ft and 0.9 Mach number, the result of adapted engine model showed improved prediction in engine thrust (overall performance parameter) by reducing the difference from 14.5 to 3.3%. Moreover, there was further improvement in the comparison of low-pressure turbine exit temperature (local performance parameter) as the difference is reduced from 3.2 to 0.4%.

Partial oxidation for improved cold starts in alcohol-fueled engines: Phase 2 topical report

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

NONE

1998-04-01

Alcohol fuels exhibit poor cold-start performance because of their low volatility. Neat alcohol engines become difficult, if not impossible, to start at temperatures close to or below freezing. Improvements in the cold-start performance (both time to start and emissions) are essential to capture the full benefits of alcohols as an alternative transportation fuel. The objective of this project was to develop a neat alcohol partial oxidation (POX) reforming technology to improve an alcohol engine`s ability to start at low temperatures (as low as {minus}30 C) and to reduce its cold-start emissions. The project emphasis was on fuel-grade ethanol (E95) butmore » the technology can be easily extended to other alcohol fuels. Ultimately a compact, on-vehicle, ethanol POX reactor was developed as a fuel system component to produce a hydrogen-rich, fuel-gas mixture for cold starts. The POX reactor is an easily controllable combustion device that allows flexibility during engine startup even in the most extreme conditions. It is a small device that is mounted directly onto the engine intake manifold. The gaseous fuel products (or reformate) from the POX reactor exit the chamber and enter the intake manifold, either replacing or supplementing the standard ethanol fuel consumed during an engine start. The combustion of the reformate during startup can reduce engine start time and tail-pipe emissions.« less

Extraction of fault component from abnormal sound in diesel engines using acoustic signals

NASA Astrophysics Data System (ADS)

Dayong, Ning; Changle, Sun; Yongjun, Gong; Zengmeng, Zhang; Jiaoyi, Hou

2016-06-01

In this paper a method for extracting fault components from abnormal acoustic signals and automatically diagnosing diesel engine faults is presented. The method named dislocation superimposed method (DSM) is based on the improved random decrement technique (IRDT), differential function (DF) and correlation analysis (CA). The aim of DSM is to linearly superpose multiple segments of abnormal acoustic signals because of the waveform similarity of faulty components. The method uses sample points at the beginning of time when abnormal sound appears as the starting position for each segment. In this study, the abnormal sound belonged to shocking faulty type; thus, the starting position searching method based on gradient variance was adopted. The coefficient of similar degree between two same sized signals is presented. By comparing with a similar degree, the extracted fault component could be judged automatically. The results show that this method is capable of accurately extracting the fault component from abnormal acoustic signals induced by faulty shocking type and the extracted component can be used to identify the fault type.

Alternating-Composition Layered Ceramic Barrier Coatings

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Zhu, Dongming

2008-01-01

Ceramic thermal and environmental barrier coatings (T/EBCs) that contain multiple layers of alternating chemical composition have been developed as improved means of protecting underlying components of gas-turbine and other heat engines against both corrosive combustion gases and high temperatures.

Using engineering control principles to inform the design of adaptive interventions: a conceptual introduction.

PubMed

Rivera, Daniel E; Pew, Michael D; Collins, Linda M

2007-05-01

The goal of this paper is to describe the role that control engineering principles can play in developing and improving the efficacy of adaptive, time-varying interventions. It is demonstrated that adaptive interventions constitute a form of feedback control system in the context of behavioral health. Consequently, drawing from ideas in control engineering has the potential to significantly inform the analysis, design, and implementation of adaptive interventions, leading to improved adherence, better management of limited resources, a reduction of negative effects, and overall more effective interventions. This article illustrates how to express an adaptive intervention in control engineering terms, and how to use this framework in a computer simulation to investigate the anticipated impact of intervention design choices on efficacy. The potential benefits of operationalizing decision rules based on control engineering principles are particularly significant for adaptive interventions that involve multiple components or address co-morbidities, situations that pose significant challenges to conventional clinical practice.

Using Engineering Control Principles to Inform the Design of Adaptive Interventions: A Conceptual Introduction

PubMed Central

Rivera, Daniel E.; Pew, Michael D.; Collins, Linda M.

2007-01-01

The goal of this paper is to describe the role that control engineering principles can play in developing and improving the efficacy of adaptive, time-varying interventions. It is demonstrated that adaptive interventions constitute a form of feedback control system in the context of behavioral health. Consequently, drawing from ideas in control engineering has the potential to significantly inform the analysis, design, and implementation of adaptive interventions, leading to improved adherence, better management of limited resources, a reduction of negative effects, and overall more effective interventions. This article illustrates how to express an adaptive intervention in control engineering terms, and how to use this framework in a computer simulation to investigate the anticipated impact of intervention design choices on efficacy. The potential benefits of operationalizing decision rules based on control engineering principles are particularly significant for adaptive interventions that involve multiple components or address co-morbidities, situations that pose significant challenges to conventional clinical practice. PMID:17169503

The 3600 hp split-torque helicopter transmission

NASA Technical Reports Server (NTRS)

White, G.

1985-01-01

Final design details of a helicopter transmission that is powered by GE twin T 700 engines each rated at 1800 hp are presented. It is demonstrated that in comparison with conventional helicopter transmission arrangements the split torque design offers: weight reduction of 15%; reduction in drive train losses of 9%; and improved reliability resulting from redundant drive paths between the two engines and the main shaft. The transmission fits within the NASA LeRC 3000 hp Test Stand and accepts the existing positions for engine inputs, main shaft, connecting drive shafts, and the cradle attachment points. One necessary change to the test stand involved gear trains of different ratio in the tail drive gearbox. Progressive uprating of engine input power from 3600 to 4500 hp twin engine rating is allowed for in the design. In this way the test transmission will provide a base for several years of analytical, research, and component development effort targeted at improving the performance and reliability of helicopter transmission.

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.

SCOUSE: Semi-automated multi-COmponent Universal Spectral-line fitting Engine

NASA Astrophysics Data System (ADS)

Henshaw, J. D.; Longmore, S. N.; Kruijssen, J. M. D.; Davies, B.; Bally, J.; Barnes, A.; Battersby, C.; Burton, M.; Cunningham, M. R.; Dale, J. E.; Ginsburg, A.; Immer, K.; Jones, P. A.; Kendrew, S.; Mills, E. A. C.; Molinari, S.; Moore, T. J. T.; Ott, J.; Pillai, T.; Rathborne, J.; Schilke, P.; Schmiedeke, A.; Testi, L.; Walker, D.; Walsh, A.; Zhang, Q.

2016-01-01

The Semi-automated multi-COmponent Universal Spectral-line fitting Engine (SCOUSE) is a spectral line fitting algorithm that fits Gaussian files to spectral line emission. It identifies the spatial area over which to fit the data and generates a grid of spectral averaging areas (SAAs). The spatially averaged spectra are fitted according to user-provided tolerance levels, and the best fit is selected using the Akaike Information Criterion, which weights the chisq of a best-fitting solution according to the number of free-parameters. A more detailed inspection of the spectra can be performed to improve the fit through an iterative process, after which SCOUSE integrates the new solutions into the solution file.

LOW-ENGINE-FRICTION TECHNOLOGY FOR ADVANCED NATURAL-GAS RECIPROCATING ENGINES

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

Victor Wong; Tian Tian; Luke Moughon

This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston and piston ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and wear. An iterative process of simulation, experimentation and analysis is being followed towards achieving the goal of demonstrating a complete optimized low-friction engine system. To date, a detailed set of piston and piston-ring dynamic and friction models have been developed and applied that illustrate the fundamental relationships among mechanical, surface/material and lubricant design parameters and friction losses. Demonstration of low-friction ring-pack designs in the Waukesha VGFmore » 18GL engine confirmed total engine FEMP (friction mean effective pressure) reduction of 7-10% from the baseline configuration without significantly increasing oil consumption or blow-by flow. This represents a substantial (30-40%) reduction of the ringpack friction alone. The measured FMEP reductions were in good agreement with the model predictions. Further improvements via piston, lubricant, and surface designs offer additional opportunities. Tests of low-friction lubricants are in progress and preliminary results are very promising. The combined analysis of lubricant and surface design indicates that low-viscosity lubricants can be very effective in reducing friction, subject to component wear for extremely thin oils, which can be mitigated with further lubricant formulation and/or engineered surfaces. Hence a combined approach of lubricant design and appropriate wear reduction offers improved potential for minimum engine friction loss. Piston friction studies indicate that a flatter piston with a more flexible skirt, together with optimizing the waviness and film thickness on the piston skirt offer significant friction reduction. Combined with low-friction ring-pack, material and lubricant parameters, a total power cylinder friction reduction of 30-50% is expected, translating to an engine efficiency increase of two percentage points from its current baseline towards the goal of 50% ARES engine efficiency. The design strategies developed in this study have promising potential for application in all modern reciprocating engines as they represent simple, low-cost methods to extract significant fuel savings. The current program has possible spinoffs and applications in other industries as well, including transportation, CHP, and diesel power generation. The progress made in this program has wide engine efficiency implications, and potential deployment of low-friction engine components or lubricants in the near term is possible as current investigations continue.« less

DEFINING THE PLAYERS IN HIGHER-ORDER NETWORKS: PREDICTIVE MODELING FOR REVERSE ENGINEERING FUNCTIONAL INFLUENCE NETWORKS

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

McDermott, Jason E.; Costa, Michelle N.; Stevens, S.L.

A difficult problem that is currently growing rapidly due to the sharp increase in the amount of high-throughput data available for many systems is that of determining useful and informative causative influence networks. These networks can be used to predict behavior given observation of a small number of components, predict behavior at a future time point, or identify components that are critical to the functioning of the system under particular conditions. In these endeavors incorporating observations of systems from a wide variety of viewpoints can be particularly beneficial, but has often been undertaken with the objective of inferring networks thatmore » are generally applicable. The focus of the current work is to integrate both general observations and measurements taken for a particular pathology, that of ischemic stroke, to provide improved ability to produce useful predictions of systems behavior. A number of hybrid approaches have recently been proposed for network generation in which the Gene Ontology is used to filter or enrich network links inferred from gene expression data through reverse engineering methods. These approaches have been shown to improve the biological plausibility of the inferred relationships determined, but still treat knowledge-based and machine-learning inferences as incommensurable inputs. In this paper, we explore how further improvements may be achieved through a full integration of network inference insights achieved through application of the Gene Ontology and reverse engineering methods with specific reference to the construction of dynamic models of transcriptional regulatory networks. We show that integrating two approaches to network construction, one based on reverse-engineering from conditional transcriptional data, one based on reverse-engineering from in situ hybridization data, and another based on functional associations derived from Gene Ontology, using probabilities can improve results of clustering as evaluated by a predictive model of transcriptional expression levels.« less

Aircraft fuel conservation technology. Task force report, September 10, 1975

NASA Technical Reports Server (NTRS)

1975-01-01

An advanced technology program is described for reduced fuel consumption in air transport. Cost benefits and estimates are given for improved engine design and components, turboprop propulsion systems, active control systems, laminar flow control, and composite primary structures.

Combining results of multiple search engines in proteomics.

PubMed

Shteynberg, David; Nesvizhskii, Alexey I; Moritz, Robert L; Deutsch, Eric W

2013-09-01

A crucial component of the analysis of shotgun proteomics datasets is the search engine, an algorithm that attempts to identify the peptide sequence from the parent molecular ion that produced each fragment ion spectrum in the dataset. There are many different search engines, both commercial and open source, each employing a somewhat different technique for spectrum identification. The set of high-scoring peptide-spectrum matches for a defined set of input spectra differs markedly among the various search engine results; individual engines each provide unique correct identifications among a core set of correlative identifications. This has led to the approach of combining the results from multiple search engines to achieve improved analysis of each dataset. Here we review the techniques and available software for combining the results of multiple search engines and briefly compare the relative performance of these techniques.

Combining Results of Multiple Search Engines in Proteomics*

PubMed Central

Shteynberg, David; Nesvizhskii, Alexey I.; Moritz, Robert L.; Deutsch, Eric W.

2013-01-01

A crucial component of the analysis of shotgun proteomics datasets is the search engine, an algorithm that attempts to identify the peptide sequence from the parent molecular ion that produced each fragment ion spectrum in the dataset. There are many different search engines, both commercial and open source, each employing a somewhat different technique for spectrum identification. The set of high-scoring peptide-spectrum matches for a defined set of input spectra differs markedly among the various search engine results; individual engines each provide unique correct identifications among a core set of correlative identifications. This has led to the approach of combining the results from multiple search engines to achieve improved analysis of each dataset. Here we review the techniques and available software for combining the results of multiple search engines and briefly compare the relative performance of these techniques. PMID:23720762

On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization

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

Dennis H. LeMieux

2004-10-01

Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land -based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCsmore » have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems; a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization.« less

Ceramic high pressure gas path seal

NASA Technical Reports Server (NTRS)

Liotta, G. C.

1987-01-01

Stage 1 ceramic shrouds (high pressure turbine gas path seal) were developed for the GE T700 turbine helicopter engine under the Army/NASA Contract NAS3-23174. This contract successfully proved the viability and benefits of a Stage 1 ceramic shroud for production application. Stage 1 ceramic shrouds were proven by extensive component and engine testing. This Stage 1 ceramic shroud, plasma sprayed ceramic (ZrOs-BY2O3) and bond coating (NiCrAlY) onto a cast metal backing, offers significant engine performance improvement. Due to the ceramic coating, the amount of cooling air required is reduced 20% resulting in a 0.5% increase in horsepower and a 0.3% decrease in specific fuel consumption. This is accomplished with a component which is lower in cost than the current production shroud. Stage 1 ceramic shrouds will be introduced into field service in late 1987.

Low Velocity Impact Behavior of Glass Filled Fiber-Reinforced Thermoplastic Engine Components

PubMed Central

Mouti, Zakaria; Westwood, Keith; Kayvantash, Kambiz; Njuguna, James

2010-01-01

This paper concerns automotive parts located underneath the engine and in particular the engine oil pan. Classically made of stamped steel or cast aluminum, new developments have allowed the manufacture oil pans with polyamide 66 reinforced by 35% weight of short glass fiber. However, polyamides have some limitations and the most significant is their response to localized impact loading. The nature of the impact considered here is of a typical stone collected from the road and projected into the oil pan.  Low velocity impact investigations were carried out using a gas gun and drop weight tower.  The study shows that the design of the oil pan has a significant contribution in the shock absorption. In addition to the material properties, the geometry and the ribbing both cleverly combined, increase the impact resistance of the component significantly. Areas of oil pan design improvement have been identified and conclusions drawn.

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.

Engineering Cellulases for Biorefinery

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

Kumar, Manoj

2010-06-27

Lignocellulosic biomass is the most abundant, least expensive renewable natural biological resource for the production of biobased products and bioenergy is important for the sustainable development of human civilization in 21st century. For making the fermentable sugars from lignocellulosic biomass, a reduction in cellulase production cost, an improvement in cellulase performance, and an increase in sugar yields are all vital to reduce the processing costs of biorefineries. Improvements in specific cellulase activities for non-complexed cellulase mixtures can be implemented through cellulase engineering based on rational design or directed evolution for each cellulase component enzyme, as well as on the reconstitutionmore » of cellulase components. In this paper, we will provide DSM's efforts in cellulase research and developments and focus on limitations. Cellulase improvement strategies based on directed evolution using screening on relevant substrates, screening for higher thermal tolerance based on activity screening approaches such as continuous culture using insoluble cellulosic substrates as a powerful selection tool for enriching beneficial cellulase mutants from the large library. We will illustrate why and how thermostable cellulases are vital for economic delivery of bioproducts from cellulosic biomass using biochemical conversion approach.« less

Near Zero Emissions at 50 Percent Thermal Efficiency

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

None, None

2012-12-31

Detroit Diesel Corporation (DDC) has successfully completed a 10 year DOE sponsored heavy-duty truck engine program, hereafter referred to as the NZ-50 program. This program was split into two major phases. The first phase was called Near-Zero Emission at 50 Percent Thermal Efficiency, and was completed in 2007. The second phase was initiated in 2006, and this phase was named Advancements in Engine Combustion Systems to Enable High-Efficiency Clean Combustion for Heavy-Duty Engines. This phase was completed in September, 2010. The key objectives of the NZ-50 program for this first phase were to: Quantify thermal efficiency degradation associated with reductionmore » of engine-out NOx emissions to the 2007 regulated level of ~1.1 g/hp-hr. Implement an integrated analytical/experimental development plan for improving subsystem and component capabilities in support of emerging engine technologies for emissions and thermal efficiency goals of the program. Test prototype subsystem hardware featuring technology enhancements and demonstrate effective application on a multi-cylinder, production feasible heavy-duty engine test-bed. Optimize subsystem components and engine controls (calibration) to demonstrate thermal efficiency that is in compliance with the DOE 2005 Joule milestone, meaning greater than 45% thermal efficiency at 2007 emission levels. Develop technology roadmap for meeting emission regulations of 2010 and beyond while mitigating the associated degradation in engine fuel consumption. Ultimately, develop technical prime-path for meeting the overall goal of the NZ-50 program, i.e., 50% thermal efficiency at 2010 regulated emissions. These objectives were successfully met during the course of the NZ-50 program. The most noteworthy achievements in this program are summarized as follows: Demonstrated technologies through advanced integrated experiments and analysis to achieve the technical objectives of the NZ-50 program with 50.2% equivalent thermal efficiency under EPA 2010 emissions regulations. Experimentally demonstrate brake efficiency of 48.5% at EPA 2010 emission level at single steady-state point. Analytically demonstrated additional brake efficiency benefits using advanced aftertreatment configuration concept and air system enhancement including, but not limited to, turbo-compound, variable valve actuator system, and new cylinder head redesign, thus helping to achieve the final program goals. Experimentally demonstrated EPA 2010 emissions over FTP cycles using advanced integrated engine and aftertreatment system. These aggressive thermal efficiency and emissions results were achieved by applying a robust systems technology development methodology. It used integrated analytical and experimental tools for subsystem component optimization encompassing advanced fuel injection system, increased EGR cooling capacity, combustion process optimization, and advanced aftertreatment technologies. Model based controls employing multiple input and output techniques enabled efficient integration of the various subsystems and ensured optimal performance of each system within the total engine package. . The key objective of the NZ-50 program for the second phase was to explore advancements in engine combustion systems using high-efficiency clean combustion (HECC) techniques to minimize cylinder-out emissions, targeting a 10% efficiency improvement. The most noteworthy achievements in this phase of the program are summarized as follows: Experimentally and analytically evaluated numerous air system improvements related to the turbocharger and variable valve actuation. Some of the items tested proved to be very successful and modifications to the turbine discovered in this program have since been incorporated into production hardware. The combustion system development continued with evaluation of various designs of the 2-step piston bowl. Significant improvements in engine emissions have been obtained, but fuel economy improvements have been tougher to realize. Development of a neural network control system progressed to the point that the system was fully functional and showing significant fuel economy gains in transient engine testing. Development of the QuantLogic injector with the capability of both a hollow cone spray during early injection and conventional diesel injection at later injection timings was undertaken and proved to be problematic. This injector was designed to be a key component in a PCCI combustion system, but this innovative fuel injector required significantly more development effort than this programâ's resources or timing would allow.« less

Net shape fabrication of Alpha Silicon Carbide turbine components

NASA Technical Reports Server (NTRS)

Storm, R. S.

1982-01-01

Development of Alpha Silicon Carbide components by net shape fabrication techniques has continued in conjunction with several turbine engine programs. Progress in injection molding of simple parts has been extended to much larger components. Turbine rotors fabricated by a one piece molding have been successfully spin tested above design speeds. Static components weighing up to 4.5 kg and 33 cc in diameter have also been produced using this technique. Use of sintering fixtures significantly improves dimensional control. A new Si-SiC composite material has also been developed with average strengths up to 1000 MPa (150 ksi) at 1200 C.

Chapter 15: Reliability of Wind Turbines

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

Sheng, Shuangwen; O'Connor, Ryan

The global wind industry has witnessed exciting developments in recent years. The future will be even brighter with further reductions in capital and operation and maintenance costs, which can be accomplished with improved turbine reliability, especially when turbines are installed offshore. One opportunity for the industry to improve wind turbine reliability is through the exploration of reliability engineering life data analysis based on readily available data or maintenance records collected at typical wind plants. If adopted and conducted appropriately, these analyses can quickly save operation and maintenance costs in a potentially impactful manner. This chapter discusses wind turbine reliability bymore » highlighting the methodology of reliability engineering life data analysis. It first briefly discusses fundamentals for wind turbine reliability and the current industry status. Then, the reliability engineering method for life analysis, including data collection, model development, and forecasting, is presented in detail and illustrated through two case studies. The chapter concludes with some remarks on potential opportunities to improve wind turbine reliability. An owner and operator's perspective is taken and mechanical components are used to exemplify the potential benefits of reliability engineering analysis to improve wind turbine reliability and availability.« less

Reliability analysis of component of affination centrifugal 1 machine by using reliability engineering

NASA Astrophysics Data System (ADS)

Sembiring, N.; Ginting, E.; Darnello, T.

2017-12-01

Problems that appear in a company that produces refined sugar, the production floor has not reached the level of critical machine availability because it often suffered damage (breakdown). This results in a sudden loss of production time and production opportunities. This problem can be solved by Reliability Engineering method where the statistical approach to historical damage data is performed to see the pattern of the distribution. The method can provide a value of reliability, rate of damage, and availability level, of an machine during the maintenance time interval schedule. The result of distribution test to time inter-damage data (MTTF) flexible hose component is lognormal distribution while component of teflon cone lifthing is weibull distribution. While from distribution test to mean time of improvement (MTTR) flexible hose component is exponential distribution while component of teflon cone lifthing is weibull distribution. The actual results of the flexible hose component on the replacement schedule per 720 hours obtained reliability of 0.2451 and availability 0.9960. While on the critical components of teflon cone lifthing actual on the replacement schedule per 1944 hours obtained reliability of 0.4083 and availability 0.9927.

19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components...

Code of Federal Regulations, 2014 CFR

2014-04-01

... engines, ground flight simulators, parts, components, and subassemblies. 10.183 Section 10.183 Customs... Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components, and... aircraft, aircraft engines, and ground flight simulators, including their parts, components, and...

19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components...

Code of Federal Regulations, 2013 CFR

2013-04-01

... engines, ground flight simulators, parts, components, and subassemblies. 10.183 Section 10.183 Customs... Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components, and... aircraft, aircraft engines, and ground flight simulators, including their parts, components, and...

19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components...

Code of Federal Regulations, 2012 CFR

2012-04-01

... engines, ground flight simulators, parts, components, and subassemblies. 10.183 Section 10.183 Customs... Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components, and... aircraft, aircraft engines, and ground flight simulators, including their parts, components, and...

Tissue engineering therapy for cardiovascular disease.

PubMed

Nugent, Helen M; Edelman, Elazer R

2003-05-30

The present treatments for the loss or failure of cardiovascular function include organ transplantation, surgical reconstruction, mechanical or synthetic devices, or the administration of metabolic products. Although routinely used, these treatments are not without constraints and complications. The emerging and interdisciplinary field of tissue engineering has evolved to provide solutions to tissue creation and repair. Tissue engineering applies the principles of engineering, material science, and biology toward the development of biological substitutes that restore, maintain, or improve tissue function. Progress has been made in engineering the various components of the cardiovascular system, including blood vessels, heart valves, and cardiac muscle. Many pivotal studies have been performed in recent years that may support the move toward the widespread application of tissue-engineered therapy for cardiovascular diseases. The studies discussed include endothelial cell seeding of vascular grafts, tissue-engineered vascular conduits, generation of heart valve leaflets, cardiomyoplasty, genetic manipulation, and in vitro conditions for optimizing tissue-engineered cardiovascular constructs.

Development and Testing of Propulsion Health Management

NASA Technical Reports Server (NTRS)

Hunter, Gary W.; Lekki, John D.; Simon, Donald L.

2012-01-01

An Integrated Vehicle Health Management system aims to maintain vehicle health through detection, diagnostics, state awareness, prognostics, and lastly, mitigation of detrimental situations for each of the vehicle subsystems and throughout the vehicle as a whole. This paper discusses efforts to advance Propulsion Health Management technology for in-flight applications to provide improved propulsion sensors measuring a range of parameters, improve ease of propulsion sensor implementation, and to assess and manage the health of gas turbine engine flow-path components. This combined work is intended to enable real-time propulsion state assessments to accurately determine the vehicle health, reduce loss of control, and to improve operator situational awareness. A unique aspect of this work is demonstration of these maturing technologies on an operational engine.

Engine component instrumentation development facility at NASA Lewis Research Center

NASA Technical Reports Server (NTRS)

Bruckner, Robert J.; Buggele, Alvin E.; Lepicovsky, Jan

1992-01-01

The Engine Components Instrumentation Development Facility at NASA Lewis is a unique aeronautics facility dedicated to the development of innovative instrumentation for turbine engine component testing. Containing two separate wind tunnels, the facility is capable of simulating many flow conditions found in most turbine engine components. This facility's broad range of capabilities as well as its versatility provide an excellent location for the development of novel testing techniques. These capabilities thus allow a more efficient use of larger and more complex engine component test facilities.

The ENABLER - Based on proven NERVA technology

NASA Astrophysics Data System (ADS)

Livingston, Julie M.; Pierce, Bill L.

The ENABLER reactor for use in a nuclear thermal propulsion engine uses the technology developed in the NERVA/Rover program, updated to incorporate advances in the technology. Using composite fuel, higher power densities per fuel element, improved radiation resistant control components and the advancements in use of carbon-carbon materials; the ENABLER can provide a specific impulse of 925 seconds, an engine thrust to weight (excluding reactor shield) approaching five, an improved initial mass in low Earth orbit and a consequent reduction in launch costs and logistics problems. This paper describes the 75,000 lbs thrust ENABLER design which is a low cost, low risk approach to meeting tommorrow's space propulsion needs.

Affordable Manufacturing Technologies Being Developed for Actively Cooled Ceramic Components

NASA Technical Reports Server (NTRS)

Bhatt, Ramakrishna T.

1999-01-01

Efforts to improve the performance of modern gas turbine engines have imposed increasing service temperature demands on structural materials. Through active cooling, the useful temperature range of nickel-base superalloys in current gas turbine engines has been extended, but the margin for further improvement appears modest. Because of their low density, high-temperature strength, and high thermal conductivity, in situ toughened silicon nitride ceramics have received a great deal of attention for cooled structures. However, high processing costs have proven to be a major obstacle to their widespread application. Advanced rapid prototyping technology, which is developing rapidly, offers the possibility of an affordable manufacturing approach.

Quiet Clean Short-haul Experimental Engine (QCSEE) under-the-wing engine composite fan blade: Preliminary design test report

NASA Technical Reports Server (NTRS)

1975-01-01

Results of tests conducted on preliminary design polymeric-composite fan blade for the under the wing (UTW) OCSEE engine are presented. During this phase of the program a total of 17preliminary OCSEE UTW composite fan blades were manufactured for various component tests including frequency characteristics, strain distribution, bench fatigue, dovetail pull, whirligig overspeed and whirligig impact. All tests were successfully completed with the exception of whirligig impact tests. Improvements in local impact capability are being evaluated for the OCSEE blade under other NASA and related programs.

Development of an Open Rotor Cycle Model in NPSS Using a Multi-Design Point Approach

NASA Technical Reports Server (NTRS)

Hendricks, Eric S.

2011-01-01

NASA's Environmentally Responsible Aviation Project and Subsonic Fixed Wing Project are focused on developing concepts and technologies which may enable dramatic reductions to the environmental impact of future generation subsonic aircraft (Refs. 1 and 2). The open rotor concept (also referred to as the Unducted Fan or advanced turboprop) may allow the achievement of this objective by reducing engine emissions and fuel consumption. To evaluate its potential impact, an open rotor cycle modeling capability is needed. This paper presents the initial development of an open rotor cycle model in the Numerical Propulsion System Simulation (NPSS) computer program which can then be used to evaluate the potential benefit of this engine. The development of this open rotor model necessitated addressing two modeling needs within NPSS. First, a method for evaluating the performance of counter-rotating propellers was needed. Therefore, a new counter-rotating propeller NPSS component was created. This component uses propeller performance maps developed from historic counter-rotating propeller experiments to determine the thrust delivered and power required. Second, several methods for modeling a counter-rotating power turbine within NPSS were explored. These techniques used several combinations of turbine components within NPSS to provide the necessary power to the propellers. Ultimately, a single turbine component with a conventional turbine map was selected. Using these modeling enhancements, an open rotor cycle model was developed in NPSS using a multi-design point approach. The multi-design point (MDP) approach improves the engine cycle analysis process by making it easier to properly size the engine to meet a variety of thrust targets throughout the flight envelope. A number of design points are considered including an aerodynamic design point, sea-level static, takeoff and top of climb. The development of this MDP model was also enabled by the selection of a simple power management scheme which schedules propeller blade angles with the freestream Mach number. Finally, sample open rotor performance results and areas for further model improvements are presented.

LOW-ENGINE-FRICTION TECHNOLOGY FOR ADVANCED NATURAL-GAS RECIPROCATING ENGINES

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

Victor W. Wong; Tian Tian; Grant Smedley

2003-08-28

This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston/ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and emissions. A detailed set of piston/ring dynamic and friction models have been developed and applied that illustrated the fundamental relationships between design parameters and friction losses. Various low-friction strategies and concepts have been explored, and engine experiments will validate these concepts. An iterative process of experimentation, simulation and analysis, will be followed with the goal of demonstrating a complete optimized low-friction engine system. As planned, MIT has developed guidelinesmore » for an initial set of low-friction piston-ring-pack designs. Current recommendations focus on subtle top-piston-ring and oil-control-ring characteristics. A full-scale Waukesha F18 engine has been installed at Colorado State University and testing of the baseline configuration is in progress. Components for the first design iteration are being procured. Subsequent work includes examining the friction and engine performance data and extending the analyses to other areas to evaluate opportunities for further friction improvement and the impact on oil consumption/emission and wear, towards demonstrating an optimized reduced-friction engine system.« less

Study on the variable cycle engine modeling techniques based on the component method

NASA Astrophysics Data System (ADS)

Zhang, Lihua; Xue, Hui; Bao, Yuhai; Li, Jijun; Yan, Lan

2016-01-01

Based on the structure platform of the gas turbine engine, the components of variable cycle engine were simulated by using the component method. The mathematical model of nonlinear equations correspondeing to each component of the gas turbine engine was established. Based on Matlab programming, the nonlinear equations were solved by using Newton-Raphson steady-state algorithm, and the performance of the components for engine was calculated. The numerical simulation results showed that the model bulit can describe the basic performance of the gas turbine engine, which verified the validity of the model.

Engineering Education for a New Era

NASA Astrophysics Data System (ADS)

Ohgaki, Shinichiro

Engineering education is composed of five components, the idea what engineering education ought to be, the knowledge in engineering fields, those who learn engineering, those who teach engineering and the stakeholders in engineering issues. The characteristics of all these five components are changing with the times. When we consider the engineering education for the next era, we should analyze the changes of all five components. Especially the knowledge and tools in engineering fields has been expanding, and advanced science and technology is casting partly a dark shadow on the modern convenient life. Moral rules or ethics for developing new products and engineering systems are now regarded as most important in engineering fields. All those who take the responsibility for engineering education should understand the change of all components in engineering education and have a clear grasp of the essence of engineering for sustainable society.

Waste heat recovery from adiabatic diesel engines by exhaust-driven Brayton cycles

NASA Technical Reports Server (NTRS)

Khalifa, H. E.

1983-01-01

An evaluation of Bryton Bottoming Systems (BBS) as waste heat recovery devices for future adiabatic diesel engines in heavy duty trucks is presented. Parametric studies were performed to evaluate the influence of external and internal design parameters on BBS performance. Conceptual design and trade-off studies were undertaken to estimate the optimum configuration, size, and cost of major hardware components. The potential annual fuel savings of long-haul trucks equipped with BBS were estimated. The addition of a BBS to a turbocharged, nonaftercooled adiabatic engine would improve fuel economy by as much as 12%. In comparison with an aftercooled, turbocompound engine, the BBS-equipped turbocharged engine would offer a 4.4% fuel economy advantage. If installed in tandem with an aftercooled turbocompound engine, the BBS could effect a 7.2% fuel economy improvement. The cost of a mass-produced 38 Bhp BBS is estimated at about $6460 or 170/Bhp. Technical and economic barriers that hinder the commercial introduction of bottoming systems were identified. Related studies in the area of waste heat recovery from adiabatic diesel engines and NASA-CR-168255 (Steam Rankine) and CR-168256 (Organic Rankine).

Final Report: Utilizing Alternative Fuel Ignition Properties to Improve SI and CI Engine Efficiency

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

Wooldridge, Margaret; Boehman, Andre; Lavoie, George

Experimental and modeling studies were completed to explore leveraging physical and chemical fuel properties for improved thermal efficiency of internal combustion engines. Fundamental studies of the ignition chemistry of ethanol and iso-octane blends and constant volume spray chamber studies of gasoline and diesel sprays supported the core research effort which used several reciprocating engine platforms. Single cylinder spark ignition (SI) engine studies were carried out to characterize the impact of ethanol/gasoline, syngas (H 2 and CO)/gasoline and other oxygenate/gasoline blends on engine performance. The results of the single-cylinder engine experiments and other data from the literature were used to trainmore » a GT Power model and to develop a knock criteria based on reaction chemistry. The models were used to interpret the experimental results and project future performance. Studies were also carried out using a state of the art, direct injection (DI) turbocharged multi- cylinder engine with piezo-actuated fuel injectors to demonstrate the promising spray and spark timing strategies from single-cylinder engine studies on the multi-cylinder engine. Key outcomes and conclusions of the studies were: 1. Efficiency benefits of ethanol and gasoline fuel blends were consistent and substantial (e.g. 5-8% absolute improvement in gross indicated thermal efficiency (GITE)). 2. The best ethanol/gasoline blend (based on maximum thermal efficiency) was determined by the engine hardware and limits based on component protection (e.g. peak in-cylinder pressure or maximum turbocharger inlet temperature) – and not by knock limits. Blends with <50% ethanol delivered significant thermal efficiency gains with conventional SI hardware while maintain good safety integrity to the engine hardware. 3. Other compositions of fuel blends including syngas (H 2 and CO) and other dilution strategies provided significant efficiency gains as well (e.g. 5% absolute improvement in ITE). 4. When the combination of engine and fuel system is not knock limited, multiple fuel injection events maintain thermal efficiency while improving engine-out emissions (e.g. CO, UHC, and particulate number).« less

E3 Success Story - Transforming and Promoting Sustainable Manufacturing in Alabama

EPA Pesticide Factsheets

Alabama E3 is expanding to other manufacturing sectors and expanding its scope. Alabama E3 now includes a workforce training and education component and is also developing a new innovation engineering green module that focuses on improving sustainability

Failure mode analysis to predict product reliability.

NASA Technical Reports Server (NTRS)

Zemanick, P. P.

1972-01-01

The failure mode analysis (FMA) is described as a design tool to predict and improve product reliability. The objectives of the failure mode analysis are presented as they influence component design, configuration selection, the product test program, the quality assurance plan, and engineering analysis priorities. The detailed mechanics of performing a failure mode analysis are discussed, including one suggested format. Some practical difficulties of implementation are indicated, drawn from experience with preparing FMAs on the nuclear rocket engine program.

Advanced supersonic propulsion study, phase 3

NASA Technical Reports Server (NTRS)

Howlett, R. A.; Johnson, J.; Sabatella, J.; Sewall, T.

1976-01-01

The variable stream control engine is determined to be the most promising propulsion system concept for advanced supersonic cruise aircraft. This concept uses variable geometry components and a unique throttle schedule for independent control of two flow streams to provide low jet noise at takeoff and high performance at both subsonic and supersonic cruise. The advanced technology offers a 25% improvement in airplane range and an 8 decibel reduction in takeoff noise, relative to first generation supersonic turbojet engines.

High Efficiency, Clean Combustion

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

Donald Stanton

2010-03-31

Energy use in trucks has been increasing at a faster rate than that of automobiles within the U.S. transportation sector. According to the Energy Information Administration (EIA) Annual Energy Outlook (AEO), a 23% increase in fuel consumption for the U.S. heavy duty truck segment is expected between 2009 to 2020. The heavy duty vehicle oil consumption is projected to grow between 2009 and 2050 while light duty vehicle (LDV) fuel consumption will eventually experience a decrease. By 2050, the oil consumption rate by LDVs is anticipated to decrease below 2009 levels due to CAFE standards and biofuel use. In contrast,more » the heavy duty oil consumption rate is anticipated to double. The increasing trend in oil consumption for heavy trucks is linked to the vitality, security, and growth of the U.S. economy. An essential part of a stable and vibrant U.S. economy is a productive U.S. trucking industry. Studies have shown that the U.S. gross domestic product (GDP) is strongly correlated to freight transport. Over 90% of all U.S. freight tonnage is transported by diesel power and over 75% is transported by trucks. Given the vital role that the trucking industry plays in the economy, improving the efficiency of the transportation of goods was a central focus of the Cummins High Efficient Clean Combustion (HECC) program. In a commercial vehicle, the diesel engine remains the largest source of fuel efficiency loss, but remains the greatest opportunity for fuel efficiency improvements. In addition to reducing oil consumption and the dependency on foreign oil, this project will mitigate the impact on the environment by meeting US EPA 2010 emissions regulations. Innovation is a key element in sustaining a U.S. trucking industry that is competitive in global markets. Unlike passenger vehicles, the trucking industry cannot simply downsize the vehicle and still transport the freight with improved efficiency. The truck manufacturing and supporting industries are faced with numerous challenges to reduce oil consumption and greenhouse gases, meet stringent emissions regulations, provide customer value, and improve safety. The HECC program successfully reduced engine fuel consumption and greenhouse gases while providing greater customer valve. The US EPA 2010 emissions standard poses a significant challenge for developing clean diesel powertrains that meet the DoE Vehicle Technologies Multi-Year Program Plan (MYPP) for fuel efficiency improvement while remaining affordable. Along with exhaust emissions, an emphasis on heavy duty vehicle fuel efficiency is being driven by increased energy costs as well as the potential regulation of greenhouse gases. An important element of the success of meeting emissions while significantly improving efficiency is leveraging Cummins component technologies such as fuel injection equipment, aftertreatment, turbomahcinery, electronic controls, and combustion systems. Innovation in component technology coupled with system integration is enabling Cummins to move forward with the development of high efficiency clean diesel products with a long term goal of reaching a 55% peak brake thermal efficiency for the engine plus aftertreatment system. The first step in developing high efficiency clean products has been supported by the DoE co-sponsored HECC program. The objectives of the HECC program are: (1) To design and develop advanced diesel engine architectures capable of achieving US EPA 2010 emission regulations while improving the brake thermal efficiency by 10% compared to the baseline (a state of the art 2007 production diesel engine). (2) To design and develop components and subsystems (fuel systems, air handling, controls, etc) to enable construction and development of multi-cylinder engines. (3) To perform an assessment of the commercial viability of the newly developed engine technology. (4) To specify fuel properties conducive to improvements in emissions, reliability, and fuel efficiency for engines using high-efficiency clean combustion (HECC) technologies. To demonstrate the technology is compatible with B20 (biodiesel). (5) To further improve the brake thermal efficiency of the engine as integrated into the vehicle. To demonstrate robustness and commercial viability of the HECC engine technology as integrated into the vehicles. The Cummins HECC program supported the Advanced Combustion Engine R&D and Fuels Technology initiatives of the DoE Vehicle Technologies Multi-Year Program Plan (MYPP). In particular, the HECC project goals enabled the DoE Vehicle Technologies Program (VTP) to meet energy-efficiency improvement targets for advanced combustion engines suitable for passenger and commercial vehicles, as well as addressing technology barriers and R&D needs that are common between passenger and commercial vehicle applications of advanced combustion engines.« less

A framework of medical equipment management system for in-house clinical engineering department.

PubMed

Chien, Chia-Hung; Huang, Yi-You; Chong, Fok-Ching

2010-01-01

Medical equipment management is an important issue for safety and cost in modern hospital operation. In addition, the use of an efficient information system effectively promotes the managing performance. In this study, we designed a framework of medical equipment management system used for in-house clinical engineering department. The system was web-based, and it integrated clinical engineering and hospital information system components. Through related information application, it efficiently improved the operation management of medical devices immediately and continuously. This system has run in the National Taiwan University Hospital. The results showed only few examples in the error analysis of medical equipment by the maintenance sub-system. The information can be used to improve work quality, to reduce the maintenance cost, and to promote the safety of medical device used in patients and clinical staffs.

Using experimental design modules for process characterization in manufacturing/materials processes laboratories

NASA Technical Reports Server (NTRS)

Ankenman, Bruce; Ermer, Donald; Clum, James A.

1994-01-01

Modules dealing with statistical experimental design (SED), process modeling and improvement, and response surface methods have been developed and tested in two laboratory courses. One course was a manufacturing processes course in Mechanical Engineering and the other course was a materials processing course in Materials Science and Engineering. Each module is used as an 'experiment' in the course with the intent that subsequent course experiments will use SED methods for analysis and interpretation of data. Evaluation of the modules' effectiveness has been done by both survey questionnaires and inclusion of the module methodology in course examination questions. Results of the evaluation have been very positive. Those evaluation results and details of the modules' content and implementation are presented. The modules represent an important component for updating laboratory instruction and to provide training in quality for improved engineering practice.

Micro- and Nanoscale Hydrogel Systems for Drug Delivery and Tissue Engineering

PubMed Central

Schwall, Christine T.; Banerjee, Ipsita A.

2009-01-01

The pursuit for targeted drug delivery systems has led to the development of highly improved biomaterials with enhanced biocompatibility and biodegradability properties. Micro- and nanoscale components of hydrogels prepared from both natural and artificial components have been gaining significant importance due to their potential uses in cell based therapies, tissue engineering, liquid micro-lenses, cancer therapy, and drug delivery. In this review some of the recent methodologies used in the preparation of a number of synthetic hydrogels such as poly(N-isopropylacrylamide) (pNIPAm), poly(ethylene glycol) (PEG), poly(ethylene oxide) (PEO), polyvinyl alcohol methylacrylate co-polymers (PVA-MA) and polylactic acid (PLA), as well as some of the natural hydrogels and their applications have been discussed in detail.

Scaffolds for peripheral nerve repair and reconstruction.

PubMed

Yi, Sheng; Xu, Lai; Gu, Xiaosong

2018-06-02

Trauma-associated peripheral nerve defect is a widespread clinical problem. Autologous nerve grafting, the current gold standard technique for the treatment of peripheral nerve injury, has many internal disadvantages. Emerging studies showed that tissue engineered nerve graft is an effective substitute to autologous nerves. Tissue engineered nerve graft is generally composed of neural scaffolds and incorporating cells and molecules. A variety of biomaterials have been used to construct neural scaffolds, the main component of tissue engineered nerve graft. Synthetic polymers (e.g. silicone, polyglycolic acid, and poly(lactic-co-glycolic acid)) and natural materials (e.g. chitosan, silk fibroin, and extracellular matrix components) are commonly used along or together to build neural scaffolds. Many other materials, including the extracellular matrix, glass fabrics, ceramics, and metallic materials, have also been used to construct neural scaffolds. These biomaterials are fabricated to create specific structures and surface features. Seeding supporting cells and/or incorporating neurotrophic factors to neural scaffolds further improve restoration effects. Preliminary studies demonstrate that clinical applications of these neural scaffolds achieve satisfactory functional recovery. Therefore, tissue engineered nerve graft provides a good alternative to autologous nerve graft and represents a promising frontier in neural tissue engineering. Copyright © 2018 Elsevier Inc. All rights reserved.

Advanced rocket propulsion

NASA Technical Reports Server (NTRS)

Obrien, Charles J.

1993-01-01

Existing NASA research contracts are supporting development of advanced reinforced polymer and metal matrix composites for use in liquid rocket engines of the future. Advanced rocket propulsion concepts, such as modular platelet engines, dual-fuel dual-expander engines, and variable mixture ratio engines, require advanced materials and structures to reduce overall vehicle weight as well as address specific propulsion system problems related to elevated operating temperatures, new engine components, and unique operating processes. High performance propulsion systems with improved manufacturability and maintainability are needed for single stage to orbit vehicles and other high performance mission applications. One way to satisfy these needs is to develop a small engine which can be clustered in modules to provide required levels of total thrust. This approach should reduce development schedule and cost requirements by lowering hardware lead times and permitting the use of existing test facilities. Modular engines should also reduce operational costs associated with maintenance and parts inventories.

High Temperature Solid Lubricant Materials for Heavy Duty and Advanced Heat Engines

NASA Technical Reports Server (NTRS)

Dellacorte, C.; Wood, J. C.

1994-01-01

Advanced engine designs incorporate higher mechanical and thermal loading to achieve efficiency improvements. This approach often leads to higher operating temperatures of critical sliding elements (e.g. piston ring/cylinder wall contacts and valve guides) which compromise the use of conventional and even advanced synthetic liquid lubricants. For these applications solid lubricants must be considered. Several novel solid lubricant composites and coatings designated PS/PM200 have been employed to dry and marginally oil lubricated contacts in advanced heat engines. These applications include cylinder kits of heavy duty diesels, and high temperature Stirling engines, sidewall seals of rotary engines, and various exhaust valve and exhaust component applications. This paper describes the tribological and thermophysical properties of these tribomaterials and reviews the results of applying them to engine applications. Other potential tribological materials and applications are also discussed with particular emphasis on heavy duty and advanced heat engines.

Sensor fault diagnosis of aero-engine based on divided flight status.

PubMed

Zhao, Zhen; Zhang, Jun; Sun, Yigang; Liu, Zhexu

2017-11-01

Fault diagnosis and safety analysis of an aero-engine have attracted more and more attention in modern society, whose safety directly affects the flight safety of an aircraft. In this paper, the problem concerning sensor fault diagnosis is investigated for an aero-engine during the whole flight process. Considering that the aero-engine is always working in different status through the whole flight process, a flight status division-based sensor fault diagnosis method is presented to improve fault diagnosis precision for the aero-engine. First, aero-engine status is partitioned according to normal sensor data during the whole flight process through the clustering algorithm. Based on that, a diagnosis model is built for each status using the principal component analysis algorithm. Finally, the sensors are monitored using the built diagnosis models by identifying the aero-engine status. The simulation result illustrates the effectiveness of the proposed method.

Sensor fault diagnosis of aero-engine based on divided flight status

NASA Astrophysics Data System (ADS)

Zhao, Zhen; Zhang, Jun; Sun, Yigang; Liu, Zhexu

2017-11-01

Fault diagnosis and safety analysis of an aero-engine have attracted more and more attention in modern society, whose safety directly affects the flight safety of an aircraft. In this paper, the problem concerning sensor fault diagnosis is investigated for an aero-engine during the whole flight process. Considering that the aero-engine is always working in different status through the whole flight process, a flight status division-based sensor fault diagnosis method is presented to improve fault diagnosis precision for the aero-engine. First, aero-engine status is partitioned according to normal sensor data during the whole flight process through the clustering algorithm. Based on that, a diagnosis model is built for each status using the principal component analysis algorithm. Finally, the sensors are monitored using the built diagnosis models by identifying the aero-engine status. The simulation result illustrates the effectiveness of the proposed method.

Analysis of Propagation Plans in NSF-Funded Education Development Projects

ERIC Educational Resources Information Center

Stanford, Courtney; Cole, Renee; Froyd, Jeff; Henderson, Charles; Friedrichsen, Debra; Khatri, Raina

2017-01-01

Increasing adoption and adaptation of promising instructional strategies and materials has been identified as a critical component needed to improve science, technology, engineering, and mathematics (STEM) education. This paper examines typical propagation practices and resulting outcomes of proposals written by developers of educational…

Learning/cost-improvement curves

NASA Technical Reports Server (NTRS)

Delionback, L. M.

1976-01-01

Review guide is an aid to manager or engineer who must determine production costs for components, systems, or services. Methods are described by which manufacturers may use historical data, task characteristics, and current cost data to estimate unit prices as function of number of units to be produced.

[The testing system for OCP of the digital X-ray machine].

PubMed

Wang, Yan; Mo, Guoming; Wang, Juru; Zhou, Tao; Yu, Jianguo

2011-09-01

In this paper, we designed a testing system for operator control panel of a high-voltage and high-frequency X-ray machine, and an online testing software for functional components, in order to help the testing engineers to improve their work efficiency.

Space Shuttle Main Engine - The Relentless Pursuit of Improvement

NASA Technical Reports Server (NTRS)

VanHooser, Katherine P.; Bradley, Douglas P.

2011-01-01

The Space Shuttle Main Engine (SSME) is the only reusable large liquid rocket engine ever developed. The specific impulse delivered by the staged combustion cycle, substantially higher than previous rocket engines, minimized volume and weight for the integrated vehicle. The dual pre-burner configuration permitted precise mixture ratio and thrust control while the fully redundant controller and avionics provided a very high degree of system reliability and health diagnosis. The main engine controller design was the first rocket engine application to incorporate digital processing. The engine was required to operate at a high chamber pressure to minimize engine volume and weight. Power level throttling was required to minimize structural loads on the vehicle early in flight and acceleration levels on the crew late in ascent. Fatigue capability, strength, ease of assembly and disassembly, inspectability, and materials compatibility were all major considerations in achieving a fully reusable design. During the multi-decade program the design evolved substantially using a series of block upgrades. A number of materials and manufacturing challenges were encountered throughout SSME s history. Significant development was required for the final configuration of the high pressure turbopumps. Fracture control was implemented to assess life limits of critical materials and components. Survival in the hydrogen environment required assessment of hydrogen embrittlement. Instrumentation systems were a challenge due to the harsh thermal and dynamic environments within the engine. Extensive inspection procedures were developed to assess the engine components between flights. The Space Shuttle Main Engine achieved a remarkable flight performance record. All flights were successful with only one mission requiring an ascent abort condition, which still resulted in an acceptable orbit and mission. This was achieved in large part via extensive ground testing to fully characterize performance and to establish acceptable life limits. During the program over a million seconds of accumulated test and flight time was achieved. Post flight inspection and assessment was a key part of assuring proper performance of the flight hardware. By the end of the program the predicted reliability had improved by a factor of four. These unique challenges, evolution of the design, and the resulting reliability will be discussed in this paper.

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.

Ceramic Technology For Advanced Heat Engines Project

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

Not Available

1990-12-01

Significant accomplishments in fabricating ceramic components for the Department of Energy (DOE), National Aeronautics and Space Administration (NASA), and Department of Defense (DoD) advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. The objective of the project is to develop the industrial technology base required for reliable ceramicsmore » for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the 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. This advanced materials technology is being developed in parallel and close coordination with the ongoing DOE and industry proof of concept engine development programs. To facilitate the rapid transfer of this technology to U.S. industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities. Abstracts prepared for appropriate papers.« less

Digital Image Correlation Techniques Applied to Large Scale Rocket Engine Testing

NASA Technical Reports Server (NTRS)

Gradl, Paul R.

2016-01-01

Rocket engine hot-fire ground testing is necessary to understand component performance, reliability and engine system interactions during development. The J-2X upper stage engine completed a series of developmental hot-fire tests that derived performance of the engine and components, validated analytical models and provided the necessary data to identify where design changes, process improvements and technology development were needed. The J-2X development engines were heavily instrumented to provide the data necessary to support these activities which enabled the team to investigate any anomalies experienced during the test program. This paper describes the development of an optical digital image correlation technique to augment the data provided by traditional strain gauges which are prone to debonding at elevated temperatures and limited to localized measurements. The feasibility of this optical measurement system was demonstrated during full scale hot-fire testing of J-2X, during which a digital image correlation system, incorporating a pair of high speed cameras to measure three-dimensional, real-time displacements and strains was installed and operated under the extreme environments present on the test stand. The camera and facility setup, pre-test calibrations, data collection, hot-fire test data collection and post-test analysis and results are presented in this paper.

Rotary-Wing Relevant Compressor Aero Research and Technology Development Activities at Glenn Research Center

NASA Technical Reports Server (NTRS)

Welch, Gerard E.; Hathaway, Michael D.; Skoch, Gary J.; Snyder, Christopher A.

2012-01-01

Technical challenges of compressors for future rotorcraft engines are driven by engine-level and component-level requirements. Cycle analyses are used to highlight the engine-level challenges for 3000, 7500, and 12000 SHP-class engines, which include retention of performance and stability margin at low corrected flows, and matching compressor type, axial-flow or centrifugal, to the low corrected flows and high temperatures in the aft stages. At the component level: power-to-weight and efficiency requirements impel designs with lower inherent aerodynamic stability margin; and, optimum engine overall pressure ratios lead to small blade heights and the associated challenges of scale, particularly increased clearance-to-span ratios. The technical challenges associated with the aerodynamics of low corrected flows and stability management impel the compressor aero research and development efforts reviewed herein. These activities include development of simple models for clearance sensitivities to improve cycle calculations, full-annulus, unsteady Navier-Stokes simulations used to elucidate stall, its inception, and the physics of stall control by discrete tip-injection, development of an actuator-duct-based model for rapid simulation of nonaxisymmetric flow fields (e.g., due inlet circumferential distortion), advanced centrifugal compressor stage development and experimentation, and application of stall control in a T700 engine.

Evaluation of Game Engines for Cross-Platform Development of Mobile Serious Games for Health.

PubMed

Kleinschmidt, Carina; Haag, Martin

2016-01-01

Studies have shown that serious games for health can improve patient compliance and help to increase the quality of medical education. Due to a growing availability of mobile devices, especially the development of cross-platform mobile apps is helpful for improving healthcare. As the development can be highly time-consuming and expensive, an alternative development process is needed. Game engines are expected to simplify this process. Therefore, this article examines the question whether using game engines for cross-platform serious games for health can simplify the development compared to the development of a plain HTML5 app. At first, a systematic review of the literature was conducted in different databases (MEDLINE, ACM and IEEE). Afterwards three different game engines were chosen, evaluated in different categories and compared to the development of a HTML5 app. This was realized by implementing a prototypical application in the different engines and conducting a utility analysis. The evaluation shows that the Marmalade engine is the best choice for development in this scenario. Furthermore, it is obvious that the game engines have great benefits against plain HTML5 development as they provide components for graphics, physics, sounds, etc. The authors recommend to use the Marmalade Engine for a cross-platform mobile Serious Game for Health.

Advanced Gas Turbine (AGT) power-train system development

NASA Technical Reports Server (NTRS)

Helms, H. E.; Johnson, R. A.; Gibson, R. K.

1982-01-01

Technical work on the design and component testing of a 74.5 kW (100 hp) advanced automotive gas turbine is described. Selected component ceramic component design, and procurement were tested. Compressor tests of a modified rotor showed high speed performance improvement over previous rotor designs; efficiency improved by 2.5%, corrected flow by 4.6%, and pressure ratio by 11.6% at 100% speed. The aerodynamic design is completed for both the gasifier and power turbines. Ceramic (silicon carbide) gasifier rotors were spin tested to failure. Improving strengths is indicated by burst speeds and the group of five rotors failed at speeds between 104% and 116% of engine rated speed. The emission results from combustor testing showed NOx levels to be nearly one order of magnitude lower than with previous designs. A one piece ceramic exhaust duct/regenerator seal platform is designed with acceptable low stress levels.

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.

Improving a data-acquisition software system with abstract data type components

NASA Technical Reports Server (NTRS)

Howard, S. D.

1990-01-01

Abstract data types and object-oriented design are active research areas in computer science and software engineering. Much of the interest is aimed at new software development. Abstract data type packages developed for a discontinued software project were used to improve a real-time data-acquisition system under maintenance. The result saved effort and contributed to a significant improvement in the performance, maintainability, and reliability of the Goldstone Solar System Radar Data Acquisition System.

Object Based Numerical Zooming Between the NPSS Version 1 and a 1-Dimensional Meanline High Pressure Compressor Design Analysis Code

NASA Technical Reports Server (NTRS)

Follen, G.; Naiman, C.; auBuchon, M.

2000-01-01

Within NASA's High Performance Computing and Communication (HPCC) program, NASA Glenn Research Center is developing an environment for the analysis/design of propulsion systems for aircraft and space vehicles called the Numerical Propulsion System Simulation (NPSS). The NPSS focuses on the integration of multiple disciplines such as aerodynamics, structures, and heat transfer, along with the concept of numerical zooming between 0- Dimensional to 1-, 2-, and 3-dimensional component engine codes. The vision for NPSS is to create a "numerical test cell" enabling full engine simulations overnight on cost-effective computing platforms. Current "state-of-the-art" engine simulations are 0-dimensional in that there is there is no axial, radial or circumferential resolution within a given component (e.g. a compressor or turbine has no internal station designations). In these 0-dimensional cycle simulations the individual component performance characteristics typically come from a table look-up (map) with adjustments for off-design effects such as variable geometry, Reynolds effects, and clearances. Zooming one or more of the engine components to a higher order, physics-based analysis means a higher order code is executed and the results from this analysis are used to adjust the 0-dimensional component performance characteristics within the system simulation. By drawing on the results from more predictive, physics based higher order analysis codes, "cycle" simulations are refined to closely model and predict the complex physical processes inherent to engines. As part of the overall development of the NPSS, NASA and industry began the process of defining and implementing an object class structure that enables Numerical Zooming between the NPSS Version I (0-dimension) and higher order 1-, 2- and 3-dimensional analysis codes. The NPSS Version I preserves the historical cycle engineering practices but also extends these classical practices into the area of numerical zooming for use within a companies' design system. What follows here is a description of successfully zooming I-dimensional (row-by-row) high pressure compressor results back to a NPSS engine 0-dimension simulation and a discussion of the results illustrated using an advanced data visualization tool. This type of high fidelity system-level analysis, made possible by the zooming capability of the NPSS, will greatly improve the fidelity of the engine system simulation and enable the engine system to be "pre-validated" prior to commitment to engine hardware.

Effect of Individual Component Life Distribution on Engine Life Prediction

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin V.; Hendricks, Robert C.; Soditus, Sherry M.

2003-01-01

The effect of individual engine component life distributions on engine life prediction was determined. A Weibull-based life and reliability analysis of the NASA Energy Efficient Engine was conducted. The engine s life at a 95 and 99.9 percent probability of survival was determined based upon the engine manufacturer s original life calculations and assumed values of each of the component s cumulative life distributions as represented by a Weibull slope. The lives of the high-pressure turbine (HPT) disks and blades were also evaluated individually and as a system in a similar manner. Knowing the statistical cumulative distribution of each engine component with reasonable engineering certainty is a condition precedent to predicting the life and reliability of an entire engine. The life of a system at a given reliability will be less than the lowest-lived component in the system at the same reliability (probability of survival). Where Weibull slopes of all the engine components are equal, the Weibull slope had a minimal effect on engine L(sub 0.1) life prediction. However, at a probability of survival of 95 percent (L(sub 5) life), life decreased with increasing Weibull slope.

Bringing Back the Social Affordances of the Paper Memo to Aerospace Systems Engineering Work

NASA Technical Reports Server (NTRS)

Davidoff, Scott; Holloway, Alexandra

2014-01-01

Model-based systems engineering (MBSE) is a relatively new field that brings together the interdisciplinary study of technological components of a project (systems engineering) with a model-based ontology to express the hierarchical and behavioral relationships between the components (computational modeling). Despite the compelling promises of the benefits of MBSE, such as improved communication and productivity due to an underlying language and data model, we observed hesitation to its adoption at the NASA Jet Propulsion Laboratory. To investigate, we conducted a six-month ethnographic field investigation and needs validation with 19 systems engineers. This paper contributes our observations of a generational shift in one of JPL's core technologies. We report on a cultural misunderstanding between communities of practice that bolsters the existing technology drag. Given the high cost of failure, we springboard our observations into a design hypothesis - an intervention that blends the social affordances of the narrative-based work flow with the rich technological advantages of explicit data references and relationships of the model-based approach. We provide a design rationale, and the results of our evaluation.

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1991-01-01

ATTAP activities were highlighted by test bed engine design and development activities; ceramic component design; materials and engine component characterization; ceramic component process development and fabrication; component rig testing; and test bed engine fabrication and testing. Specifically, ATTAP aims to develop and demonstrate the technology of structural ceramics that have the potential for competitive automotive engine life cycle cost and for operating for 3500 hours in a turbine engine environment at temperatures up to 1371 C (2500 F).

Research Institute for Technical Careers

NASA Technical Reports Server (NTRS)

Glenn, Ronald L.

1996-01-01

The NASA research grant to Wilberforce University enabled us to establish the Research Institute for Technical Careers (RITC) in order to improve the teaching of science and engineering at Wilberforce. The major components of the research grant are infrastructure development, establishment of the Wilberforce Intensive Summer Experience (WISE), and Joint Research Collaborations with NASA Scientists. (A) Infrastructure Development. The NASA grant has enabled us to improve the standard of our chemistry laboratory and establish the electronics, design, and robotics laboratories. These laboratories have significantly improved the level of instruction at Wilberforce University. (B) Wilberforce Intensive Summer Experience (WISE). The WISE program is a science and engineering bridge program for prefreshman students. It is an intensive academic experience designed to strengthen students' knowledge in mathematics, science, engineering, computing skills, and writing. (C) Joint Collaboration. Another feature of the grant is research collaborations between NASA Scientists and Wilberforce University Scientists. These collaborations have enabled our faculty and students to conduct research at NASA Lewis during the summer and publish research findings in various journals and scientific proceedings.

Conceptual design study of an improved gas turbine powertrain

NASA Technical Reports Server (NTRS)

Chapman, W. I.

1980-01-01

The conceptual design for an improved gas turbine (IGT) powertrain and vehicle was investigated. Cycle parameters, rotor systems, and component technology were reviewed and a dual rotor gas turbine concept was selected and optimized for best vehicle fuel economy. The engine had a two stage centrifugal compressor with a design pressure ratio of 5.28, two axial turbine stages with advanced high temperature alloy integral wheels, variable power turbine nozzle for turbine temperature and output torque control, catalytic combustor, and annular ceramic recuperator. The engine was rated at 54.81 kW, using water injection on hot days to maintain vehicle acceleration. The estimated vehicle fuel economy was 11.9 km/l in the combined driving cycle, 43 percent over the 1976 compact automobile. The estimated IGT production vehicle selling price was 10 percent over the comparable piston engine vehicle, but the improved fuel economy and reduced maintenance and repair resulted in a 9 percent reduction in life cycle cost.

Oxide_Oxide Ceramic Matrix Composite (CMC) Exhaust Mixer Development in the NASA Environmentally Responsible Aviation (ERA) Project

NASA Technical Reports Server (NTRS)

Kiser, James D.; Bansal, Narottam P.; Szelagowski, J.; Sokhey, J.; Heffernan, T.; Clegg, J.; Pierluissi, A.; Riedell, J.; Atmur, S.; Wyen, T.;

Tissue-engineered lymphatic graft for the treatment of lymphedema

PubMed Central

Kanapathy, Muholan; Patel, Nikhil M.; Kalaskar, Deepak M.; Mosahebi, Afshin; Mehrara, Babak J.; Seifalian, Alexander M.

2015-01-01

Background Lymphedema is a chronic debilitating condition and curative treatment is yet to be found. Tissue engineering approach, which combines cellular components, scaffold, and molecular signals hold great potential in the treatment of secondary lymphedema with the advent of lymphatic graft to reconstruct damaged collecting lymphatic vessel. This review highlights the ideal characteristics of lymphatic graft, the limitation and challenges faced, and the approaches in developing tissue-engineered lymphatic graft. Methods Literature on tissue engineering of lymphatic system and lymphatic tissue biology was reviewed. Results The prime challenge in the design and manufacturing of this graft is producing endothelialized conduit with intraluminal valves. Suitable scaffold material is needed to ensure stability and functionality of the construct. Endothelialization of the construct can be enhanced via biofunctionalization and nanotopography, which mimics extracellular matrix. Nanocomposite polymers with improved performance over existing biomaterials are likely to benefit the development of lymphatic graft. Conclusions With the in-depth understanding of tissue engineering, nanotechnology, and improved knowledge on the biology of lymphatic regeneration, the aspiration to develop successful lymphatic graft is well achievable. PMID:25248852

Measured Engine Installation Effects of Four Civil Transport Airplanes

NASA Technical Reports Server (NTRS)

Senzig, David A.; Fleming, Gregg G.; Shepherd, Kevin P.

2001-01-01

The Federal Aviation Administration's Integrated Noise Model (INM) is one of the primary tools for land use planning around airports. The INM currently calculates airplane noise lateral attenuation using the methods contained in the Society of Automotive Engineer's Aerospace Information Report No. 1751 (SAE AIR 1751). Researchers have noted that improved lateral attenuation algorithms may improve airplane noise prediction. The authors of SAE AIR 1751 based existing methods on empirical data collected from flight tests using 1960s-technology airplanes with tail-mounted engines. To determine whether the SAE AIR 1751 methods are applicable for predicting the engine installation component of lateral attenuation for airplanes with wing-mounted engines, the National Aeronautics and Space Administration (NASA) sponsored a series of flight tests during September 2000 at their Wallops Flight Facility. Four airplanes, a Boeing 767-400, a Douglas DC-9, a Dassault Falcon 2000, and a Beech KingAir, were flown through a 20 microphone array. The airplanes were flown through the array at various power settings, flap settings, and altitudes to simulate take-off and arrival configurations. This paper presents the preliminary findings of this study.

Technology for aircraft energy efficiency

NASA Technical Reports Server (NTRS)

Klineberg, J. M.

1977-01-01

Six technology programs for reducing fuel use in U.S. commercial aviation are discussed. The six NASA programs are divided into three groups: Propulsion - engine component improvement, energy efficient engine, advanced turboprops; Aerodynamics - energy efficient transport, laminar flow control; and Structures - composite primary structures. Schedules, phases, and applications of these programs are considered, and it is suggested that program results will be applied to current transport derivatives in the early 1980s and to all-new aircraft of the late 1980s and early 1990s.

Component Cost Reduction by Value Engineering: A Case Study

NASA Astrophysics Data System (ADS)

Kalluri, Vinayak; Kodali, Rambabu

2017-04-01

The concept value engineering (VE) acts to increase the value of a product through the improvement in existent functions without increasing their costs. In other words, VE is a function oriented, systematic team approach study to provide value in a product, system or service. The authors systematically explore VE through the six step framework proposed by SAVE and a case study is presented to address the concern of reduction in cost without compromising the function of a hydraulic steering cylinder through the aforementioned VE framework.

A 2.5 kW advanced technology ion thruster

NASA Technical Reports Server (NTRS)

Poeschel, R. L.

1974-01-01

A program has been conducted in order to improve the performance characteristics of 30 cm thrusters. This program was divided into three distinct, but related tasks: (1) the discharge chamber and component design modifications proposed for inclusion in the engineering model thruster were evaluated and engineering specifications were verified; (2) thrust losses which result from the contributions of double charged ions and nonaxial ion trajectories to the ion beam current were measured and (3) the specification and verification of power processor and control requirements of the engineering model thruster design were demonstrated. Proven design modifications which provide improved efficiencies are incorporated into the engineering model thruster during a structural re-design without introducing additional delay in schedule or new risks. In addition, a considerable amount of data is generated on the relation of double ion production and beam divergence to thruster parameters. Overall thruster efficiency is increased from 68% to 71% at full power, including corrections for double ion and beam divergence thrust losses.

Error-proofing test system of industrial components based on image processing

NASA Astrophysics Data System (ADS)

Huang, Ying; Huang, Tao

2018-05-01

Due to the improvement of modern industrial level and accuracy, conventional manual test fails to satisfy the test standards of enterprises, so digital image processing technique should be utilized to gather and analyze the information on the surface of industrial components, so as to achieve the purpose of test. To test the installation parts of automotive engine, this paper employs camera to capture the images of the components. After these images are preprocessed including denoising, the image processing algorithm relying on flood fill algorithm is used to test the installation of the components. The results prove that this system has very high test accuracy.

Improving Saccharomyces cerevisiae ethanol production and tolerance via RNA polymerase II subunit Rpb7.

PubMed

Qiu, Zilong; Jiang, Rongrong

2017-01-01

Classical strain engineering methods often have limitations in altering multigenetic cellular phenotypes. Here we try to improve Saccharomyces cerevisiae ethanol tolerance and productivity by reprogramming its transcription profile through rewiring its key transcription component RNA polymerase II (RNAP II), which plays a central role in synthesizing mRNAs. This is the first report on using directed evolution method to engineer RNAP II to alter S. cerevisiae strain phenotypes. Error-prone PCR was employed to engineer the subunit Rpb7 of RNAP II to improve yeast ethanol tolerance and production. Based on previous studies and the presumption that improved ethanol resistance would lead to enhanced ethanol production, we first isolated variant M1 with much improved resistance towards 8 and 10% ethanol. The ethanol titers of M1 was ~122 g/L (96.58% of the theoretical yield) under laboratory very high gravity (VHG) fermentation, 40% increase as compared to the control. DNA microarray assay showed that 369 genes had differential expression in M1 after 12 h VHG fermentation, which are involved in glycolysis, alcoholic fermentation, oxidative stress response, etc. This is the first study to demonstrate the possibility of engineering eukaryotic RNAP to alter global transcription profile and improve strain phenotypes. Targeting subunit Rpb7 of RNAP II was able to bring differential expression in hundreds of genes in S. cerevisiae , which finally led to improvement in yeast ethanol tolerance and production.

Advanced Health Management System for the Space Shuttle Main Engine

NASA Technical Reports Server (NTRS)

Davidson, Matt; Stephens, John; Rodela, Chris

2006-01-01

Pratt & Whitney Rocketdyne, Inc., in cooperation with NASA-Marshall Space Flight Center (MSFC), has developed a new Advanced Health Management System (AHMS) controller for the Space Shuttle Main Engine (SSME) that will increase the probability of successfully placing the shuttle into the intended orbit and increase the safety of the Space Transportation System (STS) launches. The AHMS is an upgrade o the current Block II engine controller whose primary component is an improved vibration monitoring system called the Real-Time Vibration Monitoring System (RTVMS) that can effectively and reliably monitor the state of the high pressure turbomachinery and provide engine protection through a new synchronous vibration redline which enables engine shutdown if the vibration exceeds predetermined thresholds. The introduction of this system required improvements and modification to the Block II controller such as redesigning the Digital Computer Unit (DCU) memory and the Flight Accelerometer Safety Cut-Off System (FASCOS) circuitry, eliminating the existing memory retention batteries, installation of the Digital Signal Processor (DSP) technology, and installation of a High Speed Serial Interface (HSSI) with accompanying outside world connectors. Test stand hot-fire testing along with lab testing have verified successful implementation and is expected to reduce the probability of catastrophic engine failures during the shuttle ascent phase and improve safely by about 23% according to the Quantitative Risk Assessment System (QRAS), leading to a safer and more reliable SSME.

Implementation of Integrated System Fault Management Capability

NASA Technical Reports Server (NTRS)

Figueroa, Fernando; Schmalzel, John; Morris, Jon; Smith, Harvey; Turowski, Mark

2008-01-01

Fault Management to support rocket engine test mission with highly reliable and accurate measurements; while improving availability and lifecycle costs. CORE ELEMENTS: Architecture, taxonomy, and ontology (ATO) for DIaK management. Intelligent Sensor Processes; Intelligent Element Processes; Intelligent Controllers; Intelligent Subsystem Processes; Intelligent System Processes; Intelligent Component Processes.

Engine rotor health monitoring: an experimental approach to fault detection and durability assessment

NASA Astrophysics Data System (ADS)

Abdul-Aziz, Ali; Woike, Mark R.; Clem, Michelle; Baaklini, George

2015-03-01

Efforts to update and improve turbine engine components in meeting flights safety and durability requirements are commitments that engine manufacturers try to continuously fulfill. Most of their concerns and developments energies focus on the rotating components as rotor disks. These components typically undergo rigorous operating conditions and are subject to high centrifugal loadings which subject them to various failure mechanisms. Thus, developing highly advanced health monitoring technology to screen their efficacy and performance is very essential to their prolonged service life and operational success. Nondestructive evaluation techniques are among the many screening methods that presently are being used to pre-detect hidden flaws and mini cracks prior to any appalling events occurrence. Most of these methods or procedures are confined to evaluating material's discontinuities and other defects that have mature to a point where failure is eminent. Hence, development of more robust techniques to pre-predict faults prior to any catastrophic events in these components is highly vital. This paper is focused on presenting research activities covering the ongoing research efforts at NASA Glenn Research Center (GRC) rotor dynamics laboratory in support of developing a fault detection system for key critical turbine engine components. Data obtained from spin test experiments of a rotor disk that relates to investigating behavior of blade tip clearance, tip timing and shaft displacement based on measured data acquired from sensor devices such as eddy current, capacitive and microwave are presented. Additional results linking test data with finite element modeling to characterize the structural durability of a cracked rotor as it relays to the experimental tests and findings is also presented. An obvious difference in the vibration response is shown between the notched and the baseline no notch rotor disk indicating the presence of some type of irregularity.

Microstructural indicators of transition mechanisms in time-dependent fatigue crack growth in nickel base superalloys

NASA Astrophysics Data System (ADS)

Heeter, Ann E.

Gas turbine engines are an important part of power generation in modern society, especially in the field of aerospace. Aerospace engines are design to last approximately 30 years and the engine components must be designed to survive for the life of the engine or to be replaced at regular intervals to ensure consumer safety. Fatigue crack growth analysis is a vital component of design for an aerospace component. Crack growth modeling and design methods date back to an origin around 1950 with a high rate of accuracy. The new generation of aerospace engines is designed to be efficient as possible and require higher operating temperatures than ever seen before in previous generations. These higher temperatures place more stringent requirements on the material crack growth performance under creep and time dependent conditions. Typically the types of components which are subject to these requirements are rotating disk components which are made from advanced materials such as nickel base superalloys. Traditionally crack growth models have looked at high temperature crack growth purely as a function of temperature and assumed that all crack growth was either controlled by a cycle dependent or time dependent mechanism. This new analysis is trying to evaluate the transition between cycle-dependent and time-dependent mechanism and the microstructural markers that characterize this transitional behavior. The physical indications include both the fracture surface morphology as well as the shape of the crack front. The research will evaluate whether crack tunneling occurs and whether it consistently predicts a transition from cycle-dependent crack growth to time-dependent crack growth. The study is part of a larger research program trying to include the effects of geometry, mission profile and environmental effects, in addition to temperature effects, as a part of the overall crack growth system. The outcome will provide evidence for various transition types and correlate those physical attributes back to the material mechanisms to improve predictive modeling capability.

The ENABLER—based on proven NERVA technology

NASA Astrophysics Data System (ADS)

Livingston, Julie M.; Pierce, Bill L.

1991-01-01

The ENABLER reactor for use in a nuclear thermal propulsion engine uses the technology developed in the NERVA/Rover program, updated to incorporate advances in the technology. Using composite fuel, higher power densities per fuel element, improved radiation resistant control components and the advancements in use of carbon-carbon materials; the ENABLER can provide a specific impulse of 925 seconds, an engine thrust to weight (excluding reactor shield) approaching five, an improved initial Mass In Low Earth Orbit (IMLEO) and a consequent reduction in launch costs and logistics problems. This paper describes the 75,000 lbs thrust ENABLER design which is a low cost, low risk approach to meeting tomorrow's space propulsion needs.

An energy management for series hybrid electric vehicle using improved dynamic programming

NASA Astrophysics Data System (ADS)

Peng, Hao; Yang, Yaoquan; Liu, Chunyu

2018-02-01

With the increasing numbers of hybrid electric vehicle (HEV), management for two energy sources, engine and battery, is more and more important to achieve the minimum fuel consumption. This paper introduces several working modes of series hybrid electric vehicle (SHEV) firstly and then describes the mathematical model of main relative components in SHEV. On the foundation of this model, dynamic programming is applied to distribute energy of engine and battery on the platform of matlab and acquires less fuel consumption compared with traditional control strategy. Besides, control rule recovering energy in brake profiles is added into dynamic programming, so shorter computing time is realized by improved dynamic programming and optimization on algorithm.

Recent Developments: PKI Square Dish for the Soleras Project

NASA Technical Reports Server (NTRS)

Rogers, W. E.

1984-01-01

The Square Dish solar collectors are subjected to rigorous design attention regarding corrosion at the site, and certification of the collector structure. The microprocessor controls and tracking mechanisms are improved in the areas of fail safe operations, durability, and low parasitic power requirements. Prototype testing demonstrates performance efficiency of approximately 72% at 730 F outlet temperature. Studies are conducted that include developing formal engineering design studies, developing formal engineering design drawing and fabrication details, establishing subcontracts for fabrication of major components, and developing a rigorous quality control system. The improved design is more cost effective to product and the extensive manuals developed for assembly and operation/maintenance result in faster field assembly and ease of operation.

Recent developments: PKI square dish for the Soleras Project

NASA Astrophysics Data System (ADS)

Rogers, W. E.

1984-03-01

The Square Dish solar collectors are subjected to rigorous design attention regarding corrosion at the site, and certification of the collector structure. The microprocessor controls and tracking mechanisms are improved in the areas of fail safe operations, durability, and low parasitic power requirements. Prototype testing demonstrates performance efficiency of approximately 72% at 730 F outlet temperature. Studies are conducted that include developing formal engineering design studies, developing formal engineering design drawing and fabrication details, establishing subcontracts for fabrication of major components, and developing a rigorous quality control system. The improved design is more cost effective to product and the extensive manuals developed for assembly and operation/maintenance result in faster field assembly and ease of operation.

Tough, Microcracking-Resistant, High-Temperature Polymer

NASA Technical Reports Server (NTRS)

Pater, Ruth H.; Razon, Pert; Smith, Ricky; Working, Dennis; Chang, Alice; Gerber, Margaret

1990-01-01

Simultaneous synthesis from thermosetting and thermoplastic components yields polyimide with outstanding properties. Involves process in which one polymer cross-linked in immediate presence of other, undergoing simultaneous linear chain extension. New material, LaRC-RP40 synthesized from high-temperature thermosetting imide prepolymer and from thermoplastic monomer. Three significantly improved properties: toughness, resistance to microcracking, and glass-transition temperature. Shows promise as high-temperature matrix resin for variety of components of aircraft engines and for use in other aerospace structures.

Model-Based Fault Diagnosis for Turboshaft Engines

NASA Technical Reports Server (NTRS)

Green, Michael D.; Duyar, Ahmet; Litt, Jonathan S.

1998-01-01

Tests are described which, when used to augment the existing periodic maintenance and pre-flight checks of T700 engines, can greatly improve the chances of uncovering a problem compared to the current practice. These test signals can be used to expose and differentiate between faults in various components by comparing the responses of particular engine variables to the expected. The responses can be processed on-line in a variety of ways which have been shown to reveal and identify faults. The combination of specific test signals and on-line processing methods provides an ad hoc approach to the isolation of faults which might not otherwise be detected during pre-flight checkout.

On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization

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

Dennis H. LeMieux

2005-04-01

Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCs havemore » been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.« less

ON-LINE THERMAL BARRIER COATING MONITORING FOR REAL-TIME FAILURE PROTECTION AND LIFE MAXIMIZATION

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

Dennis H. LeMieux

2003-10-01

Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization,'' to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability, availability, and maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCsmore » have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can, therefore, accelerate the degradation of substrate component materials and eventually lead to a premature failure of critical components and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.« less

ON-LINE THERMAL BARRIER COATING MONITORING FOR REAL-TIME FAILURE PROTECTION AND LIFE MAXIMIZATION

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

Dennis H. LeMieux

2003-07-01

Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization,'' to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability, availability, and maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCsmore » have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can, therefore, accelerate the degradation of substrate component materials and eventually lead to a premature failure of critical components and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.« less

On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization

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

Dennis H. LeMieux

2005-10-01

Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Power Generation, Inc proposed a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCs havemore » been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Power Generation, Inc. has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.« less

Experience with integrally-cast compressor and turbine components for a small, low-cost, expendable-type turbojet engine

NASA Technical Reports Server (NTRS)

Dengler, R. P.

1975-01-01

Experiences with integrally-cast compressor and turbine components during fabrication and testing of four engine assemblies of a small (29 cm (11 1/2 in.) maximum diameter) experimental turbojet engine design for an expendable application are discussed. Various operations such as metal removal, welding, and re-shaping of these components were performed in preparation of full-scale engine tests. Engines with these components were operated for a total of 157 hours at engine speeds as high as 38,000 rpm and at turbine inlet temperatures as high as 1256 K (1800 F).

19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components...

Code of Federal Regulations, 2011 CFR

2011-04-01

... Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components, and... aircraft, aircraft engines, and ground flight simulators, including their parts, components, and... United States (HTSUS) by meeting the following requirements: (1) The aircraft, aircraft engines, ground...

19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components...

Code of Federal Regulations, 2010 CFR

2010-04-01

... Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components, and... aircraft, aircraft engines, and ground flight simulators, including their parts, components, and... United States (HTSUS) by meeting the following requirements: (1) The aircraft, aircraft engines, ground...

14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

Code of Federal Regulations, 2013 CFR

2013-01-01

..., airframes, aircraft engines, propellers, appliances, or component parts for return to service after... Administrator, may approve an aircraft, airframe, aircraft engine, propeller, appliance, or component part for..., airframe, aircraft engine, propeller, appliance, or component part for return to service as provided in...

14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

Code of Federal Regulations, 2012 CFR

2012-01-01

..., airframes, aircraft engines, propellers, appliances, or component parts for return to service after... Administrator, may approve an aircraft, airframe, aircraft engine, propeller, appliance, or component part for..., airframe, aircraft engine, propeller, appliance, or component part for return to service as provided in...

14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

Code of Federal Regulations, 2011 CFR

2011-01-01

..., airframes, aircraft engines, propellers, appliances, or component parts for return to service after... Administrator, may approve an aircraft, airframe, aircraft engine, propeller, appliance, or component part for..., airframe, aircraft engine, propeller, appliance, or component part for return to service as provided in...

14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

Code of Federal Regulations, 2014 CFR

2014-01-01

..., airframes, aircraft engines, propellers, appliances, or component parts for return to service after... Administrator, may approve an aircraft, airframe, aircraft engine, propeller, appliance, or component part for..., airframe, aircraft engine, propeller, appliance, or component part for return to service as provided in...

Numerical Zooming Between a NPSS Engine System Simulation and a One-Dimensional High Compressor Analysis Code

NASA Technical Reports Server (NTRS)

Follen, Gregory; auBuchon, M.

2000-01-01

Within NASA's High Performance Computing and Communication (HPCC) program, NASA Glenn Research Center is developing an environment for the analysis/design of aircraft engines called the Numerical Propulsion System Simulation (NPSS). NPSS focuses on the integration of multiple disciplines such as aerodynamics, structures, and heat transfer along with the concept of numerical zooming between zero-dimensional to one-, two-, and three-dimensional component engine codes. In addition, the NPSS is refining the computing and communication technologies necessary to capture complex physical processes in a timely and cost-effective manner. The vision for NPSS is to create a "numerical test cell" enabling full engine simulations overnight on cost-effective computing platforms. Of the different technology areas that contribute to the development of the NPSS Environment, the subject of this paper is a discussion on numerical zooming between a NPSS engine simulation and higher fidelity representations of the engine components (fan, compressor, burner, turbines, etc.). What follows is a description of successfully zooming one-dimensional (row-by-row) high-pressure compressor analysis results back to a zero-dimensional NPSS engine simulation and a discussion of the results illustrated using an advanced data visualization tool. This type of high fidelity system-level analysis, made possible by the zooming capability of the NPSS, will greatly improve the capability of the engine system simulation and increase the level of virtual test conducted prior to committing the design to hardware.

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

Waste heat recovery on multiple low-speed reciprocating engines

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

Mayhew, R.E.

1984-09-01

With rising fuel costs, energy conservation has taken on added significance. Installation of waste heat recovery units (WHRU's) 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 also has been identified as having energy conservation potential. This paper reviews the development and implementation of a WHRU for multiple low-speed engines at the Katy (TX) 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, high-amplitude pulsating exhaust. The design of a WHRUmore » 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 a pulsation filter and structural stiffness into the various components of the WHRU to minimize vibration and improve system reliability.« less

Reusable rocket engine turbopump condition monitoring

NASA Technical Reports Server (NTRS)

Hampson, M. E.

1984-01-01

Significant improvements in engine readiness with reductions in maintenance costs and turn-around times can be achieved with an engine condition monitoring systems (CMS). The CMS provides health status of critical engine components, without disassembly, through monitoring with advanced sensors. Engine failure reports over 35 years were categorized into 20 different modes of failure. Rotor bearings and turbine blades were determined to be the most critical in limiting turbopump life. Measurement technologies were matched to each of the failure modes identified. Three were selected to monitor the rotor bearings and turbine blades: the isotope wear detector and fiberoptic deflectometer (bearings), and the fiberoptic pyrometer (blades). Signal processing algorithms were evaluated for their ability to provide useful health data to maintenance personnel. Design modifications to the Space Shuttle Main Engine (SSME) high pressure turbopumps were developed to incorporate the sensors. Laboratory test fixtures have been designed for monitoring the rotor bearings and turbine blades in simulated turbopump operating conditions.

Tribology of nitrided-coated steel-a review

NASA Astrophysics Data System (ADS)

Bhaskar, Santosh V.; Kudal, Hari N.

2017-01-01

Surface engineering such as surface treatment, coating, and surface modification are employed to increase surface hardness, minimize adhesion, and hence, to reduce friction and improve resistance to wear. To have optimal tribological performance of Physical Vapor Deposition (PVD) hard coating to the substrate materials, pretreatment of the substrate materials is always advisable to avoid plastic deformation of the substrate, which may result in eventual coating failure. The surface treatment results in hardening of the substrate and increase in load support effect. Many approaches aim to improve the adhesion of the coatings onto the substrate and nitriding is the one of the best suitable options for the same. In addition to tribological properties, nitriding leads to improved corrosion resistance. Often corrosion resistance is better than that obtainable with other surface engineering processes such as hard-chrome and nickel plating. Ability of this layer to withstand thermal stresses gives stability which extends the surface life of tools and other components exposed to heat. Most importantly, the nitrogen picked-up by the diffusion layer increases the rotating-bending fatigue strength in components. The present article reviews mainly the tribological advancement of different nitrided-coated steels based on the types of coatings, structure, and the tribo-testing parameters, in recent years.

Methodological Considerations in the Study of Earthworms in Forest Ecosystems

Treesearch

Dylan Rhea-Fournier; Grizelle Gonzalez

2017-01-01

Decades of studies have shown that soil macrofauna, especially earthworms, play dominant engineering roles in soils, affecting physical, chemical, and biological components of ecosystems. Quantifying these effects would allow crucial improvement in biogeochemical budgets and modeling, predicting response of land use and disturbance, and could be applied to...

Enhancing Mathematics (STEM) Teacher Education in Regional Australia: Pedagogical Interactions and Affect

ERIC Educational Resources Information Center

Woolcott, Geoff; Yeigh, Tony

2015-01-01

This article reports on initial findings, including the mathematics components, of a multi-institutional Science, Technology, Engineering, and Mathematics (STEM) project, "It's part of my life: Engaging university and community to enhance science and mathematics education." This project is focussed on improving the scientific and…

Advanced Earth-to-orbit propulsion technology program overview: Impact of civil space technology initiative

NASA Technical Reports Server (NTRS)

Stephenson, Frank W., Jr.

1988-01-01

The NASA Earth-to-Orbit (ETO) Propulsion Technology Program is dedicated to advancing rocket engine technologies for the development of fully reusable engine systems that will enable space transportation systems to achieve low cost, routine access to space. The program addresses technology advancements in the areas of engine life extension/prediction, performance enhancements, reduced ground operations costs, and in-flight fault tolerant engine operations. The primary objective is to acquire increased knowledge and understanding of rocket engine chemical and physical processes in order to evolve more realistic analytical simulations of engine internal environments, to derive more accurate predictions of steady and unsteady loads, and using improved structural analyses, to more accurately predict component life and performance, and finally to identify and verify more durable advanced design concepts. In addition, efforts were focused on engine diagnostic needs and advances that would allow integrated health monitoring systems to be developed for enhanced maintainability, automated servicing, inspection, and checkout, and ultimately, in-flight fault tolerant engine operations.

Damage-Tolerant, Affordable Composite Engine Cases Designed and Fabricated

NASA Technical Reports Server (NTRS)

Hopkins, Dale A.; Roberts, Gary D.; Pereira, J. Michael; Bowman, Cheryl L.

2005-01-01

An integrated team of NASA personnel, Government contractors, industry partners, and university staff have developed an innovative new technology for commercial fan cases that will substantially influence the safety and efficiency of future turbine engines. This effective team, under the direction of the NASA Glenn Research Center and with the support of the Federal Aviation Administration, has matured a new class of carbon/polymer composites and demonstrated a 30- to 50-percent improvement in specific containment capacity (blade fragment kinetic energy/containment system weight). As the heaviest engine component, the engine case/containment system greatly affects both the safety and efficiency of aircraft engines. The ballistic impact research team has developed unique test facilities and methods for screening numerous candidate material systems to replace the traditional heavy, metallic engine cases. This research has culminated in the selection of a polymer matrix composite reinforced with triaxially braided carbon fibers and technology demonstration through the fabrication of prototype engine cases for three major commercial engine manufacturing companies.

Shape Changing Airfoil

NASA Technical Reports Server (NTRS)

Ott, Eric A.

2005-01-01

Scoping of shape changing airfoil concepts including both aerodynamic analysis and materials-related technology assessment effort was performed. Three general categories of potential components were considered-fan blades, booster and compressor blades, and stator airfoils. Based on perceived contributions to improving engine efficiency, the fan blade was chosen as the primary application for a more detailed assessment. A high-level aerodynamic assessment using a GE90-90B Block 4 engine cycle and fan blade geometry indicates that blade camber changes of approximately +/-4deg would be sufficient to result in fan efficiency improvements nearing 1 percent. Constraints related to flight safety and failed mode operation suggest that use of the baseline blade shape with actuation to the optimum cruise condition during a portion of the cycle would be likely required. Application of these conditions to the QAT fan blade and engine cycle was estimated to result in an overall fan efficiency gain of 0.4 percent.

From scenarios to domain models: processes and representations

NASA Astrophysics Data System (ADS)

Haddock, Gail; Harbison, Karan

1994-03-01

The domain specific software architectures (DSSA) community has defined a philosophy for the development of complex systems. This philosophy improves productivity and efficiency by increasing the user's role in the definition of requirements, increasing the systems engineer's role in the reuse of components, and decreasing the software engineer's role to the development of new components and component modifications only. The scenario-based engineering process (SEP), the first instantiation of the DSSA philosophy, has been adopted by the next generation controller project. It is also the chosen methodology of the trauma care information management system project, and the surrogate semi-autonomous vehicle project. SEP uses scenarios from the user to create domain models and define the system's requirements. Domain knowledge is obtained from a variety of sources including experts, documents, and videos. This knowledge is analyzed using three techniques: scenario analysis, task analysis, and object-oriented analysis. Scenario analysis results in formal representations of selected scenarios. Task analysis of the scenario representations results in descriptions of tasks necessary for object-oriented analysis and also subtasks necessary for functional system analysis. Object-oriented analysis of task descriptions produces domain models and system requirements. This paper examines the representations that support the DSSA philosophy, including reference requirements, reference architectures, and domain models. The processes used to create and use the representations are explained through use of the scenario-based engineering process. Selected examples are taken from the next generation controller project.

Resin Transfer Moldable Polyimides Developed for High-Temperature Applications

NASA Technical Reports Server (NTRS)

Meador, Mary Ann

2000-01-01

High-temperature polyimides, such as PMR 15 (which was developed at the NASA Glenn Research Center at Lewis Field), are becoming an increasingly important class of materials for a variety of aerospace applications, such as aircraft engine components and propulsion and airframe components for reusable launch vehicles (RLV s). Because of their high specific strength and low density, use of these materials in place of more traditional aerospace materials, such as titanium, can significantly reduce component and vehicle weight, leading to reductions in fuel consumption (and pollutants), increases in payload and passenger capacity, and improvements in vehicle performance.

SSME component assembly and life management expert system

NASA Technical Reports Server (NTRS)

Ali, M.; Dietz, W. E.; Ferber, H. J.

1989-01-01

The space shuttle utilizes several rocket engine systems, all of which must function with a high degree of reliability for successful mission completion. The space shuttle main engine (SSME) is by far the most complex of the rocket engine systems and is designed to be reusable. The reusability of spacecraft systems introduces many problems related to testing, reliability, and logistics. Components must be assembled from parts inventories in a manner which will most effectively utilize the available parts. Assembly must be scheduled to efficiently utilize available assembly benches while still maintaining flight schedules. Assembled components must be assigned to as many contiguous flights as possible, to minimize component changes. Each component must undergo a rigorous testing program prior to flight. In addition, testing and assembly of flight engines and components must be done in conjunction with the assembly and testing of developmental engines and components. The development, testing, manufacture, and flight assignments of the engine fleet involves the satisfaction of many logistical and operational requirements, subject to many constraints. The purpose of the SSME Component Assembly and Life Management Expert System (CALMES) is to assist the engine assembly and scheduling process, and to insure that these activities utilize available resources as efficiently as possible.

Metabolic Engineering for the Production of Natural Products

PubMed Central

Pickens, Lauren B.; Tang, Yi; Chooi, Yit-Heng

2014-01-01

Natural products and natural product derived compounds play an important role in modern healthcare as frontline treatments for many diseases and as inspiration for chemically synthesized therapeutics. With advances in sequencing and recombinant DNA technology, many of the biosynthetic pathways responsible for the production of these chemically complex and pharmaceutically valuable compounds have been elucidated. With an ever expanding toolkit of biosynthetic components, metabolic engineering is an increasingly powerful method to improve natural product titers and generate novel compounds. Heterologous production platforms have enabled access to pathways from difficult to culture strains; systems biology and metabolic modeling tools have resulted in increasing predictive and analytic capabilities; advances in expression systems and regulation have enabled the fine-tuning of pathways for increased efficiency, and characterization of individual pathway components has facilitated the construction of hybrid pathways for the production of new compounds. These advances in the many aspects of metabolic engineering have not only yielded fascinating scientific discoveries but also make it an increasingly viable approach for the optimization of natural product biosynthesis. PMID:22432617

Liquid fuel injection elements for rocket engines

NASA Technical Reports Server (NTRS)

Cox, George B., Jr. (Inventor)

1993-01-01

Thrust chambers for liquid propellant rocket engines include three principal components. One of these components is an injector which contains a plurality of injection elements to meter the flow of propellants at a predetermined rate, and fuel to oxidizer mixture ratio, to introduce the mixture into the combustion chamber, and to cause them to be atomized within the combustion chamber so that even combustion takes place. Evolving from these injectors are tube injectors. These tube injectors have injection elements for injecting the oxidizer into the combustion chamber. The oxidizer and fuel must be metered at predetermined rates and mixture ratios in order to mix them within the combustion chamber so that combustion takes place smoothly and completely. Hence tube injectors are subject to improvement. An injection element for a liquid propellant rocket engine of the bipropellant type is provided which includes tangential fuel metering orifices, and a plurality of oxidizer tube injection elements whose injection tubes are also provided with tangential oxidizer entry slots and internal reed valves.

Enhancement of cellulosome-mediated deconstruction of cellulose by improving enzyme thermostability.

PubMed

Moraïs, Sarah; Stern, Johanna; Kahn, Amaranta; Galanopoulou, Anastasia P; Yoav, Shahar; Shamshoum, Melina; Smith, Matthew A; Hatzinikolaou, Dimitris G; Arnold, Frances H; Bayer, Edward A

2016-01-01

The concerted action of three complementary cellulases from Clostridium thermocellum, engineered to be stable at elevated temperatures, was examined on a cellulosic substrate and compared to that of the wild-type enzymes. Exoglucanase Cel48S and endoglucanase Cel8A, both key elements of the natural cellulosome from this bacterium, were engineered previously for increased thermostability, either by SCHEMA, a structure-guided, site-directed protein recombination method, or by consensus-guided mutagenesis combined with random mutagenesis using error-prone PCR, respectively. A thermostable β-glucosidase BglA mutant was also selected from a library generated by error-prone PCR that will assist the two cellulases in their methodic deconstruction of crystalline cellulose. The effects of a thermostable scaffoldin versus those of a largely mesophilic scaffoldin were also examined. By improving the stability of the enzyme subunits and the structural component, we aimed to improve cellulosome-mediated deconstruction of cellulosic substrates. The results demonstrate that the combination of thermostable enzymes as free enzymes and a thermostable scaffoldin was more active on the cellulosic substrate than the wild-type enzymes. Significantly, "thermostable" designer cellulosomes exhibited a 1.7-fold enhancement in cellulose degradation compared to the action of conventional designer cellulosomes that contain the respective wild-type enzymes. For designer cellulosome formats, the use of the thermostabilized scaffoldin proved critical for enhanced enzymatic performance under conditions of high temperatures. Simple improvement in the activity of a given enzyme does not guarantee its suitability for use in an enzyme cocktail or as a designer cellulosome component. The true merit of improvement resides in its ultimate contribution to synergistic action, which can only be determined experimentally. The relevance of the mutated thermostable enzymes employed in this study as components in multienzyme systems has thus been confirmed using designer cellulosome technology. Enzyme integration via a thermostable scaffoldin is critical to the ultimate stability of the complex at higher temperatures. Engineering of thermostable cellulases and additional lignocellulosic enzymes may prove a determinant parameter for development of state-of-the-art designer cellulosomes for their employment in the conversion of cellulosic biomass to soluble sugars.Graphical abstractConversion of conventional designer cellulosomes into thermophilic designer cellulosomes.

Energy efficient engine component development and integration program

NASA Technical Reports Server (NTRS)

1981-01-01

Accomplishments in the Energy Efficient Engine Component Development and Integration program during the period of April 1, 1981 through September 30, 1981 are discussed. The major topics considered are: (1) propulsion system analysis, design, and integration; (2) engine component analysis, design, and development; (3) core engine tests; and (4) integrated core/low spool testing.

Propulsion System Models for Rotorcraft Conceptual Design

NASA Technical Reports Server (NTRS)

Johnson, Wayne

2014-01-01

The conceptual design code NDARC (NASA Design and Analysis of Rotorcraft) was initially implemented to model conventional rotorcraft propulsion systems, consisting of turboshaft engines burning jet fuel, connected to one or more rotors through a mechanical transmission. The NDARC propulsion system representation has been extended to cover additional propulsion concepts, including electric motors and generators, rotor reaction drive, turbojet and turbofan engines, fuel cells and solar cells, batteries, and fuel (energy) used without weight change. The paper describes these propulsion system components, the architecture of their implementation in NDARC, and the form of the models for performance and weight. Requirements are defined for improved performance and weight models of the new propulsion system components. With these new propulsion models, NDARC can be used to develop environmentally-friendly rotorcraft designs.

Educating Tomorrow's Aerrospace Engineers by Developing and Launching Liquid-Propelled Rockets

NASA Astrophysics Data System (ADS)

Besnard, Eric; Garvey, John; Holleman, Tom; Mueller, Tom

2002-01-01

conducted at California State University, Long Beach (CSULB), in which engineering students develop and launch liquid propelled rockets. The program is articulated around two main activities, each with specific objectives. The first component of CALVEIN is a systems integration laboratory where students develop/improve vehicle subsystems and integrate them into a vehicle (Prospector-2 - P-2 - for the 2001-02 academic year - AY). This component has three main objectives: (1) Develop hands- on skills for incoming students and expose them to aerospace hardware; (2) allow for upper division students who have been involved in the program to mentor incoming students and manage small teams; and (3) provide students from various disciplines within the College of Engineering - and other universities - with the chance to develop/improve subsystems on the vehicle. Among recent student projects conducted as part of this component are: a new 1000 lbf thrust engine using pintle injector technology, which was successfully tested on Dec. 1, 2001 and flown on Prospector-2 in Feb. 2002 (developed by CSULB Mechanical and Aerospace Engineering students); a digital flight telemetry package (developed by CSULB Electrical Engineering students); a new recovery system where a mechanical system replaces pyrotechnics for parachute release (developed by CSULB Mechanical and Aerospace Engineering students); and a 1-ft payload bay to accommodate experimental payloads (e.g. "CANSATS" developed by Stanford University students). The second component of CALVEIN is a formal Aerospace System Design curriculum. In the first-semester, from top-level system requirements, the students perform functional analysis, define the various subsystems and derive their requirements. These are presented at the Systems Functional and Requirement Reviews (SFR &SRR). The methods used for validation and verification are determined. Specifications and Interface Control Documents (ICD) are generated by the student team(s). Trade studies are identified and conducted, leading to a Preliminary Design Review (PDR) at the end of the first semester. A detailed design follows, culminating in a Critical Design Review (CDR), etc. A general process suitable for a two-semester course sequence will be outlined. The project is conducted in an Integrated Product Team (IPT) environment, which includes a project manager, a systems engineer, and the various disciplines needed for the project (propulsion, aerodynamics, structures and materials, mass, CAD, thermal, fluids, etc.). Each student works with a Faculty member or industry advisor who is a specialist in his/her area. This design curriculum enhances the education of the graduates and provides future employers with engineers cognizant of and experienced in the application of Systems Engineering to a full-scale project over the entire product development cycle. For the AY01-02, the curriculum is being applied to the development of a gimbaled aerospike engine and its integration into P-3, scheduled to fly in May 2002. The paper ends with a summary of "lessons learned" from this experience. Budget issues are also addressed to demonstrate the ability to replicate such projects at other institutions with minimal costs, provided that it can be taken advantages of possible synergies between existing programs, in-house resources, and cooperation with other institutions or organizations.

A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing Part I: System Analysis, Component Identification, Additive Manufacturing, and Testing of Polymer Composites

NASA Technical Reports Server (NTRS)

Grady, Joseph E.; Haller, William J.; Poinsatte, Philip E.; Halbig, Michael C.; Schnulo, Sydney L.; Singh, Mrityunjay; Weir, Don; Wali, Natalie; Vinup, Michael; Jones, Michael G.;

Opportunities for Low Cost Titanium in Reduced Fuel Consumption, Improved Emissions, and Enhanced Durability Heavy Duty Vehicles

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

Kraft, E.H.

2002-07-22

The purpose of this study was to determine which components of heavy-duty highway vehicles are candidates for the substitution of titanium materials for current materials if the cost of those Ti components is very significantly reduced from current levels. The processes which could be used to produce those low cost components were also investigated. Heavy-duty highway vehicles are defined as all trucks and busses included in Classes 2C through 8. These include heavy pickups and vans above 8,500 lbs. GVWR, through highway tractor trailers. Class 8 is characterized as being a very cyclic market, with ''normal'' year volume, such asmore » in 2000, of approximately 240,000 new vehicles. Classes 3-7 are less cyclic, with ''normal'' i.e., year 2000, volume totaling approximately 325,000 new vehicles. Classes 3-8 are powered about 88.5% by diesel engines, and Class 2C at very roughly 83% diesel. The engine portion of the study therefore focused on diesels. Vehicle production volumes were used in estimates of the market size for candidate components.« less

Electric prototype power processor for a 30cm ion thruster

NASA Technical Reports Server (NTRS)

Biess, J. J.; Inouye, L. Y.; Schoenfeld, A. D.

1977-01-01

An electrical prototype power processor unit was designed, fabricated and tested with a 30 cm mercury ion engine for primary space propulsion. The power processor unit used the thyristor series resonant inverter as the basic power stage for the high power beam and discharge supplies. A transistorized series resonant inverter processed the remaining power for the low power outputs. The power processor included a digital interface unit to process all input commands and internal telemetry signals so that electric propulsion systems could be operated with a central computer system. The electrical prototype unit included design improvement in the power components such as thyristors, transistors, filters and resonant capacitors, and power transformers and inductors in order to reduce component weight, to minimize losses, and to control the component temperature rise. A design analysis for the electrical prototype is also presented on the component weight, losses, part count and reliability estimate. The electrical prototype was tested in a thermal vacuum environment. Integration tests were performed with a 30 cm ion engine and demonstrated operational compatibility. Electromagnetic interference data was also recorded on the design to provide information for spacecraft integration.

Improving Turbine Performance with Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

DiCarlo, James A.

2007-01-01

Under the new NASA Fundamental Aeronautics Program, efforts are on-going within the Supersonics Project aimed at the implementation of advanced SiC/SiC ceramic composites into hot section components of future gas turbine engines. Due to recent NASA advancements in SiC-based fibers and matrices, these composites are lighter and capable of much higher service temperatures than current metallic superalloys, which in turn will allow the engines to operate at higher efficiencies and reduced emissions. This presentation briefly reviews studies within Task 6.3.3 that are primarily aimed at developing physics-based concepts, tools, and process/property models for micro- and macro-structural design, fabrication, and lifing of SiC/SiC turbine components in general and airfoils in particular. Particular emphasis is currently being placed on understanding and modeling (1) creep effects on residual stress development within the component, (2) fiber architecture effects on key composite properties such as design strength, and (3) preform formation processes so that the optimum architectures can be implemented into complex-shaped components, such as turbine vanes and blades.

Observing System Simulation Experiment (OSSE) for the HyspIRI Spectrometer Mission

NASA Technical Reports Server (NTRS)

Turmon, Michael J.; Block, Gary L.; Green, Robert O.; Hua, Hook; Jacob, Joseph C.; Sobel, Harold R.; Springer, Paul L.; Zhang, Qingyuan

2010-01-01

The OSSE software provides an integrated end-to-end environment to simulate an Earth observing system by iteratively running a distributed modeling workflow based on the HyspIRI Mission, including atmospheric radiative transfer, surface albedo effects, detection, and retrieval for agile exploration of the mission design space. The software enables an Observing System Simulation Experiment (OSSE) and can be used for design trade space exploration of science return for proposed instruments by modeling the whole ground truth, sensing, and retrieval chain and to assess retrieval accuracy for a particular instrument and algorithm design. The OSSE in fra struc ture is extensible to future National Research Council (NRC) Decadal Survey concept missions where integrated modeling can improve the fidelity of coupled science and engineering analyses for systematic analysis and science return studies. This software has a distributed architecture that gives it a distinct advantage over other similar efforts. The workflow modeling components are typically legacy computer programs implemented in a variety of programming languages, including MATLAB, Excel, and FORTRAN. Integration of these diverse components is difficult and time-consuming. In order to hide this complexity, each modeling component is wrapped as a Web Service, and each component is able to pass analysis parameterizations, such as reflectance or radiance spectra, on to the next component downstream in the service workflow chain. In this way, the interface to each modeling component becomes uniform and the entire end-to-end workflow can be run using any existing or custom workflow processing engine. The architecture lets users extend workflows as new modeling components become available, chain together the components using any existing or custom workflow processing engine, and distribute them across any Internet-accessible Web Service endpoints. The workflow components can be hosted on any Internet-accessible machine. This has the advantages that the computations can be distributed to make best use of the available computing resources, and each workflow component can be hosted and maintained by their respective domain experts.

High Temperature Wireless Communication And Electronics For Harsh Environment Applications

NASA Technical Reports Server (NTRS)

Hunter, G. W.; Neudeck, P. G.; Beheim, G. M.; Ponchak, G. E.; Chen, L.-Y

2007-01-01

In order for future aerospace propulsion systems to meet the increasing requirements for decreased maintenance, improved capability, and increased safety, the inclusion of intelligence into the propulsion system design and operation becomes necessary. These propulsion systems will have to incorporate technology that will monitor propulsion component conditions, analyze the incoming data, and modify operating parameters to optimize propulsion system operations. This implies the development of sensors, actuators, and electronics, with associated packaging, that will be able to operate under the harsh environments present in an engine. However, given the harsh environments inherent in propulsion systems, the development of engine-compatible electronics and sensors is not straightforward. The ability of a sensor system to operate in a given environment often depends as much on the technologies supporting the sensor element as the element itself. If the supporting technology cannot handle the application, then no matter how good the sensor is itself, the sensor system will fail. An example is high temperature environments where supporting technologies are often not capable of operation in engine conditions. Further, for every sensor going into an engine environment, i.e., for every new piece of hardware that improves the in-situ intelligence of the components, communication wires almost always must follow. The communication wires may be within or between parts, or from the engine to the controller. As more hardware is added, more wires, weight, complexity, and potential for unreliability is also introduced. Thus, wireless communication combined with in-situ processing of data would significantly improve the ability to include sensors into high temperature systems and thus lead toward more intelligent engine systems. NASA Glenn Research Center (GRC) is presently leading the development of electronics, communication systems, and sensors capable of prolonged stable operation in harsh 500C environments. This has included world record operation of SiC-based transistor technology (including packaging) that has demonstrated continuous electrical operation at 500C for over 2000 hours. Based on SiC electronics, development of high temperature wireless communication has been on-going. This work has concentrated on maturing the SiC electronic devices for communication purposes as well as the passive components such as resistors and capacitors needed to enable a high temperature wireless system. The objective is to eliminate wires associated with high temperature sensors which add weight to a vehicle and can be a cause of sensor unreliability. This paper discusses the development of SiC based electronics and wireless communications technology for harsh environment applications such as propulsion health management systems and in Venus missions. A brief overview of the future directions in sensor technology is given including maturing of near-room temperature "Lick and Stick" leak sensor technology for possible implementation in the Crew Launch Vehicle program. Then an overview of high temperature electronics and the development of high temperature communication systems is presented. The maturity of related technologies such as sensor and packaging will also be discussed. It is concluded that a significant component of efforts to improve the intelligence of harsh environment operating systems is the development and implementation of high temperature wireless technology

Tracking and Control of Gas Turbine Engine Component Damage/Life

NASA Technical Reports Server (NTRS)

Jaw, Link C.; Wu, Dong N.; Bryg, David J.

2003-01-01

This paper describes damage mechanisms and the methods of controlling damages to extend the on-wing life of critical gas turbine engine components. Particularly, two types of damage mechanisms are discussed: creep/rupture and thermo-mechanical fatigue. To control these damages and extend the life of engine hot-section components, we have investigated two methodologies to be implemented as additional control logic for the on-board electronic control unit. This new logic, the life-extending control (LEC), interacts with the engine control and monitoring unit and modifies the fuel flow to reduce component damages in a flight mission. The LEC methodologies were demonstrated in a real-time, hardware-in-the-loop simulation. The results show that LEC is not only a new paradigm for engine control design, but also a promising technology for extending the service life of engine components, hence reducing the life cycle cost of the engine.

Envisioning engineering education and practice in the coming intelligence convergence era — a complex adaptive systems approach

NASA Astrophysics Data System (ADS)

Noor, Ahmed K.

2013-12-01

Some of the recent attempts for improving and transforming engineering education are reviewed. The attempts aim at providing the entry level engineers with the skills needed to address the challenges of future large-scale complex systems and projects. Some of the frontier sectors and future challenges for engineers are outlined. The major characteristics of the coming intelligence convergence era (the post-information age) are identified. These include the prevalence of smart devices and environments, the widespread applications of anticipatory computing and predictive / prescriptive analytics, as well as a symbiotic relationship between humans and machines. Devices and machines will be able to learn from, and with, humans in a natural collaborative way. The recent game changers in learnscapes (learning paradigms, technologies, platforms, spaces, and environments) that can significantly impact engineering education in the coming era are identified. Among these are open educational resources, knowledge-rich classrooms, immersive interactive 3D learning, augmented reality, reverse instruction / flipped classroom, gamification, robots in the classroom, and adaptive personalized learning. Significant transformative changes in, and mass customization of, learning are envisioned to emerge from the synergistic combination of the game changers and other technologies. The realization of the aforementioned vision requires the development of a new multidisciplinary framework of emergent engineering for relating innovation, complexity and cybernetics, within the future learning environments. The framework can be used to treat engineering education as a complex adaptive system, with dynamically interacting and communicating components (instructors, individual, small, and large groups of learners). The emergent behavior resulting from the interactions can produce progressively better, and continuously improving, learning environment. As a first step towards the realization of the vision, intelligent adaptive cyber-physical ecosystems need to be developed to facilitate collaboration between the various stakeholders of engineering education, and to accelerate the development of a skilled engineering workforce. The major components of the ecosystems include integrated knowledge discovery and exploitation facilities, blended learning and research spaces, novel ultra-intelligent software agents, multimodal and autonomous interfaces, and networked cognitive and tele-presence robots.

Overview of NASA/OAST efforts related to manufacturing technology

NASA Technical Reports Server (NTRS)

Saunders, N. T.

1976-01-01

Activities of the Office of Aeronautics and Space Technology (OAST) in a number of areas related to manufacturing technology are considered. In the computer-aided design area improved approaches are developed for the design of specific classes of components or structural subsystems. A generalized approach for the design of a complete aerospace vehicle is also developed. Efforts directed toward an increased use of composite materials in aerospace structures are also discussed and attention is given to projects concerned with the manufacture of turbine engine components.

A new generation T56 turboprop engine

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

McIntire, W.L.

1984-06-01

The focus of the T56 Series IV turboprop engine development program is to improve power and fuel consumption through incorporation of demonstrated technology improvements while retaining the long term durability and cost effective design of the T56 family. The T56-A-427, the Navy Series IV derivative of the 5000 shp (3728.5 kW) class T56 turboprop engine, resulted from over ten years of technology development via Advanced Turbine Engine Gas Generator (ATEGG), Joint Technology Demonstrator Engine (JTDE), and advanced component programs at Allison Gas Turbine Operations. An example of government and industry cooperation to transfer advanced gas turbine technology is the Airmore » Force Engine Model Derivative Program (EMDP). The initial full-scale demonstration in this program confirmed a 10-1/2% reduction in specific fuel consumption (sfc) and a power growth of 21% in the basic T56 frame. Continued early demonstrations and development by IR and D, Navy funds, and Allison discretionary funds showed a further sfc reduction to 13% and power increase of 28%. The full-scale development program is now underway to provide production engines in late 1986. Engines will be available for the Grumman E-2 and C-2 aircraft, with follow-on adaptions for Lockheed C-130/L100 and P-3 aircraft, and generator sets for DD 963, DDG 993, CG 47 and DDG 51 warships.« less

30 CFR 36.48 - Tests of surface temperature of engine and components of the cooling system.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Tests of surface temperature of engine and... temperature of engine and components of the cooling system. (a) The surface temperatures of the engine... components shall have reached their respective equilibrium temperatures. The exhaust cooling system shall be...

30 CFR 36.48 - Tests of surface temperature of engine and components of the cooling system.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Tests of surface temperature of engine and... temperature of engine and components of the cooling system. (a) The surface temperatures of the engine... components shall have reached their respective equilibrium temperatures. The exhaust cooling system shall be...

30 CFR 36.48 - Tests of surface temperature of engine and components of the cooling system.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Tests of surface temperature of engine and... temperature of engine and components of the cooling system. (a) The surface temperatures of the engine... components shall have reached their respective equilibrium temperatures. The exhaust cooling system shall be...

High Temperature Concentrated Solar Power Using Liquid Metal

NASA Astrophysics Data System (ADS)

Henry, Asegun

One of the most attractive ways to try and reduce the cost of concentrated solar power (CSP) is to increase the system efficiency and the biggest loss in the system occurs in the conversion of heat to electricity via heat engine. Heat engines that utilize turbomachinery currently operate near their thermodynamic limitations and thus one of the only ways to improve heat engine efficiency is to increase the turbine inlet temperature. Significant effort is being devoted to the development of supercritical CO2 heat engines, but the most efficient heat engines are combined cycles, which reach efficiencies as high as 60%. However, such heat engines require turbine inlet temperatures ~1300-1500C, which is far beyond what is currently feasible with the state of the art molten salt infrastructure. In working towards the development of a system that can operate in the 1300-1500C temperature range, the most significant challenges lie in the materials and forming functional and reliable components out of new materials. One of the most attractive options from a cost and heat transfer perspective is to use liquid metals, such as tin and aluminum-silicon alloys along with a ceramic based infrastructure. This talk will overview ongoing efforts in the Atomistic Simulation and Energy (ASE) research group at Georgia Tech to develop prototype components such as an efficient high temperature cavity receiver, pumps and valves that can make a liquid metal based CSP infrastructure realizable.

Materials Problems in Chemical Liquid-Propellant Rocket Systems

NASA Technical Reports Server (NTRS)

Gilbert, L. L.

1959-01-01

With the advent of the space age, new adjustments in technical thinking and engineering experience are necessary. There is an increasing and extensive interest in the utilization of materials for components to be used at temperatures ranging from -423 to over 3500 deg F. This paper presents a description of the materials problems associated with the various components of chemical liquid rocket systems. These components include cooled and uncooled thrust chambers, injectors, turbine drive systems, propellant tanks, and cryogenic propellant containers. In addition to materials limitations associated with these components, suggested research approaches for improving materials properties are made. Materials such as high-temperature alloys, cermets, carbides, nonferrous alloys, plastics, refractory metals, and porous materials are considered.

Advanced General Aviation Turbine Engine (GATE) concepts

NASA Technical Reports Server (NTRS)

Lays, E. J.; Murray, G. L.

1979-01-01

Concepts are discussed that project turbine engine cost savings through use of geometrically constrained components designed for low rotational speeds and low stress to permit manufacturing economies. Aerodynamic development of geometrically constrained components is recommended to maximize component efficiency. Conceptual engines, airplane applications, airplane performance, engine cost, and engine-related life cycle costs are presented. The powerplants proposed offer encouragement with respect to fuel efficiency and life cycle costs, and make possible remarkable airplane performance gains.

Methods of Si based ceramic components volatilization control in a gas turbine engine

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

Garcia-Crespo, Andres Jose; Delvaux, John; Dion Ouellet, Noemie

A method of controlling volatilization of silicon based components in a gas turbine engine includes measuring, estimating and/or predicting a variable related to operation of the gas turbine engine; correlating the variable to determine an amount of silicon to control volatilization of the silicon based components in the gas turbine engine; and injecting silicon into the gas turbine engine to control volatilization of the silicon based components. A gas turbine with a compressor, combustion system, turbine section and silicon injection system may be controlled by a controller that implements the control method.

Optimization of Multicomponent Behavioral and Biobehavioral Interventions for the Prevention and Treatment of HIV/AIDS

PubMed Central

Collins, Linda M.; Kugler, Kari C.; Gwadz, Marya Viorst

2015-01-01

To move society toward an AIDS-free generation, behavioral interventions for prevention and treatment of HIV/AIDS must be not only effective, but also cost-effective, efficient, and readily scalable. The purpose of this article is to introduce to the HIV/AIDS research community the multiphase optimization strategy (MOST), a new methodological framework inspired by engineering principles and designed to develop behavioral interventions that have these important characteristics. Many behavioral interventions comprise multiple components. In MOST, randomized experimentation is conducted to assess the individual performance of each intervention component, and whether its presence/absence/setting has an impact on the performance of other components. This information is used to engineer an intervention that meets a specific optimization criterion, defined a priori in terms of effectiveness, cost, cost-effectiveness, and/or scalability. MOST will enable intervention science to develop a coherent knowledge base about what works and does not work. Ultimately this will improve behavioral interventions systematically and incrementally. PMID:26238037

Optimization of Multicomponent Behavioral and Biobehavioral Interventions for the Prevention and Treatment of HIV/AIDS.

PubMed

Collins, Linda M; Kugler, Kari C; Gwadz, Marya Viorst

2016-01-01

To move society toward an AIDS-free generation, behavioral interventions for prevention and treatment of HIV/AIDS must be not only effective, but also cost-effective, efficient, and readily scalable. The purpose of this article is to introduce to the HIV/AIDS research community the multiphase optimization strategy (MOST), a new methodological framework inspired by engineering principles and designed to develop behavioral interventions that have these important characteristics. Many behavioral interventions comprise multiple components. In MOST, randomized experimentation is conducted to assess the individual performance of each intervention component, and whether its presence/absence/setting has an impact on the performance of other components. This information is used to engineer an intervention that meets a specific optimization criterion, defined a priori in terms of effectiveness, cost, cost-effectiveness, and/or scalability. MOST will enable intervention science to develop a coherent knowledge base about what works and does not work. Ultimately this will improve behavioral interventions systematically and incrementally.

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

Gangopadhyay, Arup; McWatt, D. G.; Zdrodowski, R. J.

Engine oils play a critical role in friction reduction. Improvements in engine oil technology steadily improved fuel economy as the industry moved through ILSAC GF-1 to GF-5 specifications. These improvements were influenced by changes in base oil chemistry, development of new friction modifiers and their treat levels, and the total additive package consisting of various other components. However, the improvements are incremental and further fuel consumption reduction opportunities are becoming more challenging. Polyalkylene glycol (PAG) based engine oils are being explored as a step forward for significant fuel consumption reduction. Although PAG fluids are used in many industrial applications, itsmore » application as an engine oil has been explored in a limited way. The objective of this project is to deep dive in exploring the applicability of PAG technology in engine oil, understanding the benefits, and limitations, elucidating the mechanism(s) for friction benefits, if any, and finally recommending how to address any limitations. The project was designed in four steps, starting with selection of lubricant technology, followed by friction and wear evaluations in laboratory bench tests which are relatively simple and inexpensive and also served as a screener for further evaluation. Selected formulations were chosen for more complex engine component level tests i.e., motored valvetrain friction and wear, piston ring friction using a motored single cylinder, and motored engine tests. A couple of formulations were further selected based on component level tests for engine dyno tests i.e., Sequence VID (ASTM D6709) for fuel economy, Sequence IVA (ASTM D6891) for valvetrain wear, and Sequence VG (ASTM D6593) for sludge and varnish protection. These are some of the industry standard tests required for qualifying engine oils. Out of these tests, a single PAG oil was selected for chassis roll dynamometer tests for fuel economy and emission measurements using FTP (Federal Test Procedure) metro/highway cycles. Five different PAG chemistries were selected by varying the starting alcohol, the oxide monomers (ethylene oxide, propylene oxide, or butylene oxide), capped or uncapped, homopolymer or random copolymer. All formulations contained a proprietary additive package and one which contained additional antiwear and friction modifier additives. Laboratory bench tests (Pin-on-Disk, High Frequency Reciprocating Rig (HFRR), Block-on-Ring, Mini-Traction Machine (MTM) identified formulations having friction, wear, and load carrying characteristics similar to or better than baseline GF-5 SAE 5W-20 oil. Motored valvetrain and motored piston ring friction tests showed nearly 50% friction reduction for some of the PAG formulations compared to GF-5 SAE 5W-20 oil. Motored engine tests showed up to 15% friction benefit over GF-5 SAE 5W-20 oil. It was observed that friction benefits are more related to PAG base oil chemistry than their lower viscosity compared to GF-5 SAE 5W-20 oil. Analysis of wear surfaces from laboratory bench tests and bucket tappets from motored valvetrain tests confirmed the presence of PAG molecules. The adsorption of these polar molecules is believed to be reason for friction reduction. However, the wear surfaces also had thin tribo-film derived from additive components. The tribo-film consisting of phosphates, sulfides, and molybdenum disulfide (when molybdenum additive was present) were observed for both GF-5 SAE 5W-20 and PAG fluids. However, when using PAG fluids, motored valvetrain tests showed high initial wear, which is believed to be due to delay in protective tribo-film formation. After the initial wear, the wear rate of PAG fluids was comparable to GF-5 SAE 5W-20 oil. The PAG oil containing additional antiwear and friction reducing additives showed low initial wear as expected. However, when this oil was evaluated in Sequence IVA test, it showed initially low wear comparable to GF-5 oil but wear accelerated with oil aging indicating rapid deterioration of additive components. ASTM Sequence VG test showed good sludge protection capability but failed to meet varnish rating for GF-5 requirement. Chassis roll dynamometer tests with PAG oil 15-1 showed about 1% fuel economy benefit over GF-5 SAE 5W-20 oil in EPA city cycles only and when the oil was slightly aged (500 miles). No fuel economy benefits could be observed in combined EPA metro/highway cycles. Also, no fuel economy benefit could be observed with continued (500- 10000 miles) oil aging. However, the emission level was comparable to the reference oil and was within EPA limits. Analysis of the PAG oil following tests showed low iron content although additive components were significantly degraded. The results indicate that PAG fluids have significant friction reduction potential but there are challenges with wear and varnish protection capabilities. These limitations are primarily because the selected additive components were chosen to provide a fluid with no metal content that forms little or no sulphated ash. Significant development work is needed to identify additive components compatible with PAG chemistry including their solubility in PAG oil. Miscibility of PAG fluids with mineral base oil is another challenge for oil change service. There is PAG chemistry (oil soluble PAG, OSP) which is soluble in mineral oils but the formulation explored in this investigation did not show significant friction reduction in motored engine tests. Again, highlighting the need for additive development for specific PAG chemistry. The thermal oxidation behavior of these oils has not been explored in this investigation and needs attention.« less

CF6 High Pressure Compressor and Turbine Clearance Evaluations

NASA Technical Reports Server (NTRS)

Radomski, M. A.; Cline, L. D.

1981-01-01

In the CF6 Jet Engine Diagnostics Program the causes of performance degradation were determined for each component of revenue service engines. It was found that a significant contribution to performance degradation was caused by increased airfoil tip radial clearances in the high pressure compressor and turbine areas. Since the influence of these clearances on engine performance and fuel consumption is significant, it is important to accurately establish these relatonships. It is equally important to understand the causes of clearance deterioration so that they can be reduced or eliminated. The results of factory engine tests run to enhance the understanding of the high pressure compressor and turbine clearance effects on performance are described. The causes of clearance deterioration are indicated and potential improvements in clearance control are discussed.

An Architecture, System Engineering, and Acquisition Approach for Space System Software Resiliency

NASA Astrophysics Data System (ADS)

Phillips, Dewanne Marie

Software intensive space systems can harbor defects and vulnerabilities that may enable external adversaries or malicious insiders to disrupt or disable system functions, risking mission compromise or loss. Mitigating this risk demands a sustained focus on the security and resiliency of the system architecture including software, hardware, and other components. Robust software engineering practices contribute to the foundation of a resilient system so that the system "can take a hit to a critical component and recover in a known, bounded, and generally acceptable period of time". Software resiliency must be a priority and addressed early in the life cycle development to contribute a secure and dependable space system. Those who develop, implement, and operate software intensive space systems must determine the factors and systems engineering practices to address when investing in software resiliency. This dissertation offers methodical approaches for improving space system resiliency through software architecture design, system engineering, increased software security, thereby reducing the risk of latent software defects and vulnerabilities. By providing greater attention to the early life cycle phases of development, we can alter the engineering process to help detect, eliminate, and avoid vulnerabilities before space systems are delivered. To achieve this objective, this dissertation will identify knowledge, techniques, and tools that engineers and managers can utilize to help them recognize how vulnerabilities are produced and discovered so that they can learn to circumvent them in future efforts. We conducted a systematic review of existing architectural practices, standards, security and coding practices, various threats, defects, and vulnerabilities that impact space systems from hundreds of relevant publications and interviews of subject matter experts. We expanded on the system-level body of knowledge for resiliency and identified a new software architecture framework and acquisition methodology to improve the resiliency of space systems from a software perspective with an emphasis on the early phases of the systems engineering life cycle. This methodology involves seven steps: 1) Define technical resiliency requirements, 1a) Identify standards/policy for software resiliency, 2) Develop a request for proposal (RFP)/statement of work (SOW) for resilient space systems software, 3) Define software resiliency goals for space systems, 4) Establish software resiliency quality attributes, 5) Perform architectural tradeoffs and identify risks, 6) Conduct architecture assessments as part of the procurement process, and 7) Ascertain space system software architecture resiliency metrics. Data illustrates that software vulnerabilities can lead to opportunities for malicious cyber activities, which could degrade the space mission capability for the user community. Reducing the number of vulnerabilities by improving architecture and software system engineering practices can contribute to making space systems more resilient. Since cyber-attacks are enabled by shortfalls in software, robust software engineering practices and an architectural design are foundational to resiliency, which is a quality that allows the system to "take a hit to a critical component and recover in a known, bounded, and generally acceptable period of time". To achieve software resiliency for space systems, acquirers and suppliers must identify relevant factors and systems engineering practices to apply across the lifecycle, in software requirements analysis, architecture development, design, implementation, verification and validation, and maintenance phases.

Air Force Civil Engineer Center Management of Energy Savings Performance Contracts Needs Improvement

DTIC Science & Technology

2016-05-04

audits on Air Force ESPCs. Background ESPCs provide a way for the private sector to finance Federal Government energy savings projects . ESPC is a...through DoD Instruction23 requires that any funds paid by a DoD Component pursuant to a private-sector- financed energy project be from funds made...Defense F r a u d , W a s t e & A b u s e DODIG-2016-087 ( Project No. D2015-D000CI-0200.00) │ i Results in Brief Air Force Civil Engineer Center

Overview of Aerothermodynamic Loads Definition Study

NASA Technical Reports Server (NTRS)

Povinelli, L. A.

1985-01-01

The Aerothermodynamic Loads Definition were studied to develop methods to more accurately predict the operating environment in the space shuttle main engine (SSME) components. Development of steady and time-dependent, three-dimensional viscous computer codes and experimental verification and engine diagnostic testing are considered. The steady, nonsteady, and transient operating loads are defined to accurately predict powerhead life. Improvements in the structural durability of the SSME turbine drive systems depends on the knowledge of the aerothermodynamic behavior of the flow through the preburner, turbine, turnaround duct, gas manifold, and injector post regions.

The NASA Aircraft Energy Efficiency Program

NASA Technical Reports Server (NTRS)

Klineberg, J. M.

1978-01-01

The objective of the NASA Aircraft Energy Efficiency Program is to accelerate the development of advanced technology for more energy-efficient subsonic transport aircraft. This program will have application to current transport derivatives in the early 1980s and to all-new aircraft of the late 1980s and early 1990s. Six major technology projects were defined that could result in fuel savings in commercial aircraft: (1) Engine Component Improvement, (2) Energy Efficient Engine, (3) Advanced Turboprops, (4) Energy Efficiency Transport (aerodynamically speaking), (5) Laminar Flow Control, and (6) Composite Primary Structures.

Reducing the Time and Cost of Testing Engines

NASA Technical Reports Server (NTRS)

2004-01-01

Producing a new aircraft engine currently costs approximately $1 billion, with 3 years of development time for a commercial engine and 10 years for a military engine. The high development time and cost make it extremely difficult to transition advanced technologies for cleaner, quieter, and more efficient new engines. To reduce this time and cost, NASA created a vision for the future where designers would use high-fidelity computer simulations early in the design process in order to resolve critical design issues before building the expensive engine hardware. To accomplish this vision, NASA's Glenn Research Center initiated a collaborative effort with the aerospace industry and academia to develop its Numerical Propulsion System Simulation (NPSS), an advanced engineering environment for the analysis and design of aerospace propulsion systems and components. Partners estimate that using NPSS has the potential to dramatically reduce the time, effort, and expense necessary to design and test jet engines by generating sophisticated computer simulations of an aerospace object or system. These simulations will permit an engineer to test various design options without having to conduct costly and time-consuming real-life tests. By accelerating and streamlining the engine system design analysis and test phases, NPSS facilitates bringing the final product to market faster. NASA's NPSS Version (V)1.X effort was a task within the Agency s Computational Aerospace Sciences project of the High Performance Computing and Communication program, which had a mission to accelerate the availability of high-performance computing hardware and software to the U.S. aerospace community for its use in design processes. The technology brings value back to NASA by improving methods of analyzing and testing space transportation components.

Ceramic bearings for use in gas turbine engines

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin V.

1988-01-01

Three decades of research by U.S. industry and government laboratories have produced a vast body of data related to the use of ceramic rolling element bearings and bearing components for aircraft gas turbine engines. Materials such as alumina, silicon carbide, titanium carbide, silicon nitride, and a crystallized glass ceramic have been investigated. Rolling-element endurance tests and analysis of full-complement bearings have been performed. Materials and bearing design methods have continuously improved over the years. This paper reviews a wide range of data and analyses with emphasis on how early NASA contributions as well as more recent data can enable the engineer or metallurgist to determine just where ceramic bearings are most applicable for gas turbines.

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1991-01-01

This report summarizes work performed in support of the development and demonstration of a structural ceramic technology for automotive gas turbine engines. The AGT101 regenerated gas turbine engine developed under the previous DOE/NASA Advanced Gas Turbine (AGT) program is being utilized for verification testing of the durability of next-generation ceramic components and their suitability for service at reference powertrain design conditions. Topics covered in this report include ceramic processing definition and refinement, design improvements to the test bed engine and test rigs, and design methodologies related to ceramic impact and fracture mechanisms. Appendices include reports by ATTAP subcontractors addressing the development of silicon nitride and silicon carbide families of materials and processes.

Energy efficient engine: High pressure turbine uncooled rig technology report

NASA Technical Reports Server (NTRS)

Gardner, W. B.

1979-01-01

Results obtained from testing five performance builds (three vane cascades and two rotating rigs of the Energy Efficient Engine uncooled rig have established the uncooled aerodynamic efficiency of the high-pressure turbine at 91.1 percent. This efficiency level was attained by increasing the rim speed and annulus area (AN(2)), and by increasing the turbine reaction level. The increase in AN(2) resulted in a performance improvement of 1.15 percent. At the design point pressure ratio, the increased reaction level rig demonstrated an efficiency of 91.1 percent. The results of this program have verified the aerodynamic design assumptions established for the Energy Efficient Engine high-pressure turbine component.

Sensor Based Engine Life Calculation: A Probabilistic Perspective

NASA Technical Reports Server (NTRS)

Guo, Ten-Huei; Chen, Philip

2003-01-01

It is generally known that an engine component will accumulate damage (life usage) during its lifetime of use in a harsh operating environment. The commonly used cycle count for engine component usage monitoring has an inherent range of uncertainty which can be overly costly or potentially less safe from an operational standpoint. With the advance of computer technology, engine operation modeling, and the understanding of damage accumulation physics, it is possible (and desirable) to use the available sensor information to make a more accurate assessment of engine component usage. This paper describes a probabilistic approach to quantify the effects of engine operating parameter uncertainties on the thermomechanical fatigue (TMF) life of a selected engine part. A closed-loop engine simulation with a TMF life model is used to calculate the life consumption of different mission cycles. A Monte Carlo simulation approach is used to generate the statistical life usage profile for different operating assumptions. The probabilities of failure of different operating conditions are compared to illustrate the importance of the engine component life calculation using sensor information. The results of this study clearly show that a sensor-based life cycle calculation can greatly reduce the risk of component failure as well as extend on-wing component life by avoiding unnecessary maintenance actions.

Bone tissue engineering: state of the art and future trends.

PubMed

Salgado, António J; Coutinho, Olga P; Reis, Rui L

2004-08-09

Although several major progresses have been introduced in the field of bone regenerative medicine during the years, current therapies, such as bone grafts, still have many limitations. Moreover, and in spite of the fact that material science technology has resulted in clear improvements in the field of bone substitution medicine, no adequate bone substitute has been developed and hence large bone defects/injuries still represent a major challenge for orthopaedic and reconstructive surgeons. It is in this context that TE has been emerging as a valid approach to the current therapies for bone regeneration/substitution. In contrast to classic biomaterial approach, TE is based on the understanding of tissue formation and regeneration, and aims to induce new functional tissues, rather than just to implant new spare parts. The present review pretends to give an exhaustive overview on all components needed for making bone tissue engineering a successful therapy. It begins by giving the reader a brief background on bone biology, followed by an exhaustive description of all the relevant components on bone TE, going from materials to scaffolds and from cells to tissue engineering strategies, that will lead to "engineered" bone. Scaffolds processed by using a methodology based on extrusion with blowing agents.

Applications of zeolites in biotechnology and medicine - a review.

PubMed

Bacakova, Lucie; Vandrovcova, Marta; Kopova, Ivana; Jirka, Ivan

2018-05-01

Zeolites are microporous tectosilicates of natural or synthetic origin, which have been extensively used in various technological applications, e.g. as catalysts and as molecular sieves, for separating and sorting various molecules, for water and air purification, including removal of radioactive contaminants, for harvesting waste heat and solar heat energy, for adsorption refrigeration, as detergents, etc. These applications of zeolites were typically related with their porous character, their high adsorption capacity, and their ion exchange properties. This review is focused on potential or already practically implemented applications of zeolites in biotechnology and medicine. Zeolites are promising for environment protection, detoxication of animal and human organisms, improvement of the nutrition status and immunity of farm animals, separation of various biomolecules and cells, construction of biosensors and detection of biomarkers of various diseases, controlled drug and gene delivery, radical scavenging, and particularly tissue engineering and biomaterial coating. As components of scaffolds for bone tissue engineering, zeolites can deliver oxygen to cells, can stimulate osteogenic cell differentiation, and can inhibit bone resorption. Zeolites can also act as oxygen reservoirs, and can improve cell performance in vascular and skin tissue engineering and wound healing. When deposited on metallic materials for bone implantation, zeolite films showed anticorrosion effects, and improved the osseointegration of these implants. In our studies, silicalite-1 films deposited on silicon or stainless steel substrates improved the adhesion, growth, viability and osteogenic differentiation of human osteoblast-like Saos-2 cells. Zeolites have been clinically used as components of haemostatics, e.g. in the Advanced Clotting Sponge, as gastroprotective drugs, e.g. Absorbatox® 2.4D, or as antioxidative agents (Klinobind®). Some zeolites are highly cytotoxic and carcinogenic, e.g. erionite. However, in other zeolites, the antiproliferative and pro-apoptotic effects can be used for tumor therapy.

Integration of magnetic bearings in the design of advanced gas turbine engines

NASA Technical Reports Server (NTRS)

Storace, Albert F.; Sood, Devendra K.; Lyons, James P.; Preston, Mark A.

1994-01-01

Active magnetic bearings provide revolutionary advantages for gas turbine engine rotor support. These advantages include tremendously improved vibration and stability characteristics, reduced power loss, improved reliability, fault-tolerance, and greatly extended bearing service life. The marriage of these advantages with innovative structural network design and advanced materials utilization will permit major increases in thrust to weight performance and structural efficiency for future gas turbine engines. However, obtaining the maximum payoff requires two key ingredients. The first key ingredient is the use of modern magnetic bearing technologies such as innovative digital control techniques, high-density power electronics, high-density magnetic actuators, fault-tolerant system architecture, and electronic (sensorless) position estimation. This paper describes these technologies. The second key ingredient is to go beyond the simple replacement of rolling element bearings with magnetic bearings by incorporating magnetic bearings as an integral part of the overall engine design. This is analogous to the proper approach to designing with composites, whereby the designer tailors the geometry and load carrying function of the structural system or component for the composite instead of simply substituting composites in a design originally intended for metal material. This paper describes methodologies for the design integration of magnetic bearings in gas turbine engines.

Genetic engineering of tomato to improve nutritional quality, resistance to abiotic and biotic stresses, and for non-food applications

USDA-ARS?s Scientific Manuscript database

Fruits and vegetables are key components of a well-balanced nutritious diet because they contain phytonutrients that are believed to have an overall positive effect on human health. In some instances, consumption of dietary phytonutrients, including vitamins, flavonoids, minerals, carotenoids, organ...

Study and Test to Confirm Automobile Drivetrain Components to Improve Fuel Economy : Volume 2. The Drivetrain Design Process With an Automatic Transmission

DOT National Transportation Integrated Search

1979-05-01

This report presents the key thought processes that are used by the drivetrain designer in matching an engine to a given vehicle with specific performance goals in mind. This report provides those uninitiated in this aspect of automotive design valua...

Improving the Usefulness of Concept Maps as a Research Tool for Science Education

ERIC Educational Resources Information Center

Van Zele, Els; Lenaerts, Josephina; Wieme, Willem

2004-01-01

The search for authentic science research tools to evaluate student understanding in a hybrid learning environment with a large multimedia component has resulted in the use of concept maps as a representation of student's knowledge organization. One hundred and seventy third-semester introductory university-level engineering students represented…

Automated SDI Services. (Selective Dissemination of Information).

ERIC Educational Resources Information Center

Altmann, Berthold

An automated SDI service based on tapes supplied by DDC, Science Abstracts, and Engineering Index is evaluated as a component element of the entire HDL information system. Current studies for improving the efficiency are briefly described,--in particular, the establishment of a parameter reference service that should shorten the lead-time for the…

Improved Life Prediction of Turbine Engine Components Using a Finite Element Based Software Called Zencrack

DTIC Science & Technology

2003-09-01

application .................................................. 5-42 5.10 Different materials within crack-block...5-30 Figure 5-29 - Application of required user edge node sets... applications . Users have at their disposal all of the capabilities within these finite element programs and may, if desired, include any number of

Real-Time Aircraft Engine-Life Monitoring

NASA Technical Reports Server (NTRS)

Klein, Richard

2014-01-01

This project developed an inservice life-monitoring system capable of predicting the remaining component and system life of aircraft engines. The embedded system provides real-time, inflight monitoring of the engine's thrust, exhaust gas temperature, efficiency, and the speed and time of operation. Based upon this data, the life-estimation algorithm calculates the remaining life of the engine components and uses this data to predict the remaining life of the engine. The calculations are based on the statistical life distribution of the engine components and their relationship to load, speed, temperature, and time.

Materials and Designs for High-Efficacy LED Light Engines

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

Ibbetson, James; Gresback, Ryan

Cree, Inc. conducted a narrow-band downconverter (NBD) materials development and implementation program which will lead to warm-white LED light engines with enhanced efficacy via improved spectral efficiency with respect to the human eye response. New red (600-630nm) NBD materials could result in as much as a 20% improvement in warm-white efficacy at high color quality relative to conventional phosphor-based light sources. Key program innovations included: high quantum yield; narrow peak width; minimized component-level losses due to “cross-talk” and light scattering among red and yellow-green downconverters; and improved reliability to reach parity with conventional phosphors. NBD-enabled downconversion efficiency gains relative tomore » conventional phosphors yielded an end-of-project LED light engine efficacy of >160 lm/W at room temperature and 35 A/cm2, with a correlated color temperature (CCT) of ~3500K and >90 CRI (Color Rending Index). NBD-LED light engines exhibited equivalent luminous flux and color point maintenance at >1,000 hrs. of highly accelerated reliability testing as conventional phosphor LEDs. A demonstration luminaire utilizing an NBD-based LED light engine had a steady-state system efficacy of >150 lm/W at ~3500K and >90 CRI, which exceeded the 2014 DOE R&D Plan luminaire milestone for FY17 of >150 lm/W at just 80 CRI.« less

Materials-Enabled High-Efficiency (MEHE) Heavy-Duty Diesel Engines

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

Kass, M.; Veliz, M.

2011-09-30

The purpose of this Cooperative Research and Development Agreement (CRADA) between UTBattelle, Inc. and Caterpillar, Inc. was to improve diesel engine efficiency by incorporating advanced materials to enable higher combustion pressures and temperatures necessary for improved combustion. The project scope also included novel materials for use in advanced components and designs associated with waste-heat recovery and other concepts for improved thermal efficiency. Caterpillar initially provided ORNL with a 2004 Tier 2 C15 ACERT diesel engine (designed for on-highway use) and two 600 hp motoring dynamometers. The first year of the CRADA effort was focused on establishing a heavy-duty experimental enginemore » research cell. First year activities included procuring, installing and commissioning the cell infrastructure. Infrastructure components consisted of intake air handling system, water tower, exhaust handling system, and cell air conditioning. Other necessary infrastructure items included the fuel delivery system and bottled gas handling to support the analytical instrumentation. The second year of the CRADA focused on commissioning the dynamometer system to enable engine experimentation. In addition to the requirements associated with the dynamometer controller, the electrical system needed a power factor correction system to maintain continuity with the electrical grid. During the second year the engine was instrumented and baseline operated to confirm performance and commission the dynamometer. The engine performance was mapped and modeled according to requirements provided by Caterpillar. This activity was further supported by a Work-for-Others project from Caterpillar to evaluate a proprietary modeling system. A second Work-for-Others activity was performed to evaluate a novel turbocharger design. This project was highly successful and may lead to new turbocharger designs for Caterpillar heavy-duty diesel engines. During the third (and final) year of the CRADA, a novel valve material was evaluated to assess high temperature performance and durability. A series of prototype valves, composed of a unique nickel-alloy was placed in the engine head. The engine was aggressively operated using a transient test cycle for 200 hours. The valve recession was periodically measured to determine valve performance. Upon completion of the test the valves were removed and returned to Caterpillar for additional assessment. Industrial in-kind support was available throughout the project period. Review of the status and research results were carried out on a regular basis (meetings and telecons) which included direction for future work activities. A significant portion of the industrial support was in the form of information exchange and technical consultation.« less

AST Critical Propulsion and Noise Reduction Technologies for Future Commercial Subsonic Engines Area of Interest 1.0: Reliable and Affordable Control Systems

NASA Technical Reports Server (NTRS)

Myers, William; Winter, Steve

2006-01-01

The General Electric Reliable and Affordable Controls effort under the NASA Advanced Subsonic Technology (AST) Program has designed, fabricated, and tested advanced controls hardware and software to reduce emissions and improve engine safety and reliability. The original effort consisted of four elements: 1) a Hydraulic Multiplexer; 2) Active Combustor Control; 3) a Variable Displacement Vane Pump (VDVP); and 4) Intelligent Engine Control. The VDVP and Intelligent Engine Control elements were cancelled due to funding constraints and are reported here only to the state they progressed. The Hydraulic Multiplexing element developed and tested a prototype which improves reliability by combining the functionality of up to 16 solenoids and servo-valves into one component with a single electrically powered force motor. The Active Combustor Control element developed intelligent staging and control strategies for low emission combustors. This included development and tests of a Controlled Pressure Fuel Nozzle for fuel sequencing, a Fuel Multiplexer for individual fuel cup metering, and model-based control logic. Both the Hydraulic Multiplexer and Controlled Pressure Fuel Nozzle system were cleared for engine test. The Fuel Multiplexer was cleared for combustor rig test which must be followed by an engine test to achieve full maturation.

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.

The role of mechanical loading in ligament tissue engineering.

PubMed

Benhardt, Hugh A; Cosgriff-Hernandez, Elizabeth M

2009-12-01

Tissue-engineered ligaments have received growing interest as a promising alternative for ligament reconstruction when traditional transplants are unavailable or fail. Mechanical stimulation was recently identified as a critical component in engineering load-bearing tissues. It is well established that living tissue responds to altered loads through endogenous changes in cellular behavior, tissue organization, and bulk mechanical properties. Without the appropriate biomechanical cues, new tissue formation lacks the necessary collagenous organization and alignment for sufficient load-bearing capacity. Therefore, tissue engineers utilize mechanical conditioning to guide tissue remodeling and improve the performance of ligament grafts. This review provides a comparative analysis of the response of ligament and tendon fibroblasts to mechanical loading in current bioreactor studies. The differential effect of mechanical stimulation on cellular processes such as protease production, matrix protein synthesis, and cell proliferation is examined in the context of tissue engineering design.

Integration of Engineering Education by High School Teachers to Meet Standards in the Physics Classroom

NASA Astrophysics Data System (ADS)

Kersten, Jennifer Anna

In recent years there has been increasing interest in engineering education at the K-12 level, which has resulted in states adopting engineering standards as a part of their academic science standards. From a national perspective, the basis for research into engineering education at the K-12 level is the belief that it is of benefit to student learning, including to "improve student learning and achievement in science and mathematics; increase awareness of engineering and the work of engineers; boost youth interest in pursuing engineering as a career; and increase the technological literacy of all students" (National Research Council, 2009a, p. 1). The above has led to a need to understand how teachers are currently implementing engineering education in their classrooms. High school physics teachers have a history of implementing engineering design projects in their classrooms, thus providing an appropriate setting to look for evidence of quality engineering education at the high school level. Understanding the characteristics of quality engineering integration can inform curricular and professional development efforts for teachers asked to implement engineering in their classrooms. Thus, the question that guided this study is: How, and to what extent, do physics teachers represent quality engineering in a physics unit focused on engineering? A case study research design was implemented for this project. Three high school physics teachers were participants in this study focused on the integration of engineering education into the physics classroom. The data collected included observations, interviews, and classroom documents that were analyzed using the Framework for Quality K-12 Engineering Education (Moore, Glancy et al., 2013). The results provided information about the areas of the K-12 engineering framework addressed during these engineering design projects, and detailed the quality of these lesson components. The results indicate that all of the design projects contained components of the indicators central to engineering education, although with varied degrees of success. In addition, each design project contained aspects important to the development of students' understanding of engineering and that promote important professional skills used by engineers. The implications of this work are discussed at the teacher, school, professional development, and policy levels.

Space Shuttle Main Engine: Advanced Health Monitoring System

NASA Technical Reports Server (NTRS)

Singer, Chirs

1999-01-01

The main gola of the Space Shuttle Main Engine (SSME) Advanced Health Management system is to improve flight safety. To this end the new SSME has robust new components to improve the operating margen and operability. The features of the current SSME health monitoring system, include automated checkouts, closed loop redundant control system, catastropic failure mitigation, fail operational/ fail-safe algorithms, and post flight data and inspection trend analysis. The features of the advanced health monitoring system include: a real time vibration monitor system, a linear engine model, and an optical plume anomaly detection system. Since vibration is a fundamental measure of SSME turbopump health, it stands to reason that monitoring the vibration, will give some idea of the health of the turbopumps. However, how is it possible to avoid shutdown, when it is not necessary. A sensor algorithm has been developed which has been exposed to over 400 test cases in order to evaluate the logic. The optical plume anomaly detection (OPAD) has been developed to be a sensitive monitor of engine wear, erosion, and breakage.

Edge printability: techniques used to evaluate and improve extreme wafer edge printability

NASA Astrophysics Data System (ADS)

Roberts, Bill; Demmert, Cort; Jekauc, Igor; Tiffany, Jason P.

2004-05-01

The economics of semiconductor manufacturing have forced process engineers to develop techniques to increase wafer yield. Improvements in process controls and uniformities in all areas of the fab have reduced film thickness variations at the very edge of the wafer surface. This improved uniformity has provided the opportunity to consider decreasing edge exclusions, and now the outermost extents of the wafer must be considered in the yield model and expectations. These changes have increased the requirements on lithography to improve wafer edge printability in areas that previously were not even coated. This has taxed all software and hardware components used in defining the optical focal plane at the wafer edge. We have explored techniques to determine the capabilities of extreme wafer edge printability and the components of the systems that influence this printability. We will present current capabilities and new detection techniques and the influence that the individual hardware and software components have on edge printability. We will show effects of focus sensor designs, wafer layout, utilization of dummy edge fields, the use of non-zero overlay targets and chemical/optical edge bead optimization.

Improving Thermomechanical Properties of SiC/SiC Composites

NASA Technical Reports Server (NTRS)

DiCarlo, James A.; Bhatt, Ramakrishna T.

2006-01-01

Today, a major thrust toward improving the thermomechanical properties of engine components lies in the development of fiber-reinforced silicon carbide matrix composite materials, including SiC-fiber/SiC-matrix composites. These materials are lighter in weight and capable of withstanding higher temperatures, relative to state-of-the-art metallic alloys and oxide-matrix composites for which maximum use temperatures are in the vicinity of 1,100 C. In addition, the toughness or damage tolerance of the SiC-matrix composites is significantly greater than that of unreinforced silicon-based monolithic ceramics. For successful application in advanced engine systems, the SiC-matrix composites should be able to withstand component service stresses and temperatures for the desired component lifetimes. Inasmuch as the high-temperature structural lives of ceramic materials are typically limited by creep-induced growth of flaws, a key property required of such composite materials is high resistance to creep under conditions of use. Also, the thermal conductivity of the materials should be as high as possible so as to minimize component thermal gradients and thermal stresses. A state-of-the-art SiC-matrix composite is typically fabricated in a three-step process: (1) fabrication of a component-shaped architectural preform reinforced by thermally stable high-performance fibers, (2) chemical-vapor infiltration (CVI) of a fiber-coating material such as boron nitride (BN) into the preform, and (3) infiltration of an SiC-based matrix into the remaining porosity in the preform. Generally, the matrices of the highest-performing composites are fabricated by initial use of a CVI SiC matrix component that is typically more thermally stable and denser than matrix components formed by processes other than CVI. As such, the initial SiC matrix component made by CVI provides better environmental protection to the coated fibers embedded within it. Also, the denser CVI SiC imparts to the composite better resistance to propagation of cracks, enhanced thermal conductivity, and higher creep resistance.

Ultra High Temperature (UHT) SiC Fiber (Phase 2)

NASA Technical Reports Server (NTRS)

Dicarlo, James A.; Jacobson, Nathan S.; Lizcano, Maricela; Bhatt, Ramakrishna T.

2015-01-01

Silicon-carbide fiber-reinforced silicon-carbide ceramic matrix composites (SiCSiC CMC) are emerginglightweight re-usable structural materials not only for hot section components in gas turbine engines, but also for controlsurfaces and leading edges of reusable hypersonic vehicles as well as for nuclear propulsion and reactor components. Ithas been shown that when these CMC are employed in engine hot-section components, the higher the upper usetemperature (UUT) of the SiC fiber, the more performance benefits are accrued, such as higher operating temperatures,reduced component cooling air, reduced fuel consumption, and reduced emissions. The first generation of SiCSiC CMC with a temperature capability of 2200-2400F are on the verge of being introduced into the hot-section components ofcommercial and military gas turbine engines.Today the SiC fiber type currently recognized as the worlds best in terms ofthermo-mechanical performance is the Sylramic-iBN fiber. This fiber was previously developed by the PI at NASA GRC using patented processes to improve the high-cost commercial Sylramic fiber, which in turn was derived from anotherlow-cost low-performance commercial fiber. Although the Sylramic-iBN fiber shows state-of-the art creep and rupture resistance for use temperatures above 2550oF, NASA has shown by fundamental creep studies and model developmentthat its microstructure and creep resistance could theoretically be significantly improved to produce an Ultra HighTemperature (UHT) SiC fiber.This Phase II Seedling Fund effort has been focused on the key objective of effectively repeating the similar processes used for producing the Sylramic-iBN fiber using a design of experiments approach to first understand the cause of the less than optimum Sylramic-iBN microstructure and then attempting to develop processconditions that eliminate or minimize these key microstructural issues. In so doing, it is predicted that that theseadvanced process could result in an UHT SiC fiber with 20 times more creep resistance than the Sylramic-iBN fiber,which in turn would allow SiCSiC CMC to operate up to 2700oF and above, thereby further enhancing the performancebenefits of SiCSiC components in aero-propulsion engines. It was also envisioned that the fiber processes developedduring Phase II efforts would not only reduce production costs for the UHT fiber by using low-cost precursor fibers andcombined processes, but also allow the UHT fibers to be directly produced in preforms of the precursor fibers, possibly atthe facilities of the CMC fabricator.

Orbit Transfer Vehicle (OTV) advanced expander cycle engine point design study. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

Mellish, J. A.

1980-01-01

Engine control techniques were established and new technology requirements were identified. The designs of the components and engine were prepared in sufficient depth to calculate engine and component weights and envelopes, turbopump efficiencies and recirculation leakage rates, and engine performance. Engine design assumptions are presented along with the structural design criteria.

Advanced Constituents and Processes for Ceramic Composite Engine Components

NASA Technical Reports Server (NTRS)

Yun, H. M.; DiCarlo, J. A.; Bhatt, R. T.

2004-01-01

The successful replacement of metal alloys by ceramic matrix composites (CMC) in hot-section engine components will depend strongly on optimizing the processes and properties of the CMC microstructural constituents so that they can synergistically provide the total CMC system with improved temperature capability and with the key properties required by the components for long-term structural service. This presentation provides the results of recent activities at NASA aimed at developing advanced silicon carbide (Sic) fiber-reinforced hybrid Sic matrix composite systems that can operate under mechanical loading and oxidizing conditions for hundreds of hours at 2400 and 2600 F, temperatures well above current metal capability. These SiC/SiC composite systems are lightweight (-30% metal density) and, in comparison to monolithic ceramics and carbon fiber-reinforced ceramic composites, are able to reliably retain their structural properties for long times under aggressive engine environments. It is shown that the improved temperature capability of the SiC/SiC systems is related first to the NASA development of the Sylramic-iBN Sic fiber, which displays high thermal stability, creep resistance, rupture resistance, and thermal conductivity, and possesses an in-situ grown BN surface layer for added environmental durability. This fiber is simply derived from Sylramic Sic fiber type that is currently produced at ATK COI Ceramics. Further capability is then derived by using chemical vapor infiltration (CVI) to form the initial portion of the hybrid Sic matrix. Because of its high creep resistance and thermal conductivity, the CVI Sic matrix is a required base constituent for all the high temperature SiC/SiC systems. By subsequently thermo- mechanical-treating the CMC preform, which consists of the S ylramic-iBN fibers and CVI Sic matrix, process-related defects in the matrix are removed, further improving matrix and CMC creep resistance and conductivity.

14 CFR 33.53 - Engine system and component tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine system and component tests. 33.53 Section 33.53 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.53 Engine system and...

14 CFR 33.91 - Engine system and component tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine system and component tests. 33.91 Section 33.91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.91 Engine system and...

14 CFR 33.91 - Engine system and component tests.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engine system and component tests. 33.91 Section 33.91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.91 Engine system and...

14 CFR 33.91 - Engine system and component tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Engine system and component tests. 33.91 Section 33.91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.91 Engine system and...

Membrane engineering via trans unsaturated fatty acids production improves Escherichia coli robustness and production of biorenewables.

PubMed

Tan, Zaigao; Yoon, Jong Moon; Nielsen, David R; Shanks, Jacqueline V; Jarboe, Laura R

2016-05-01

Constructing microbial biocatalysts that produce biorenewables at economically viable yields and titers is often hampered by product toxicity. For production of short chain fatty acids, membrane damage is considered the primary mechanism of toxicity, particularly in regards to membrane integrity. Previous engineering efforts in Escherichia coli to increase membrane integrity, with the goal of increasing fatty acid tolerance and production, have had mixed results. Herein, a novel approach was used to reconstruct the E. coli membrane by enabling production of a novel membrane component. Specifically, trans unsaturated fatty acids (TUFA) were produced and incorporated into the membrane of E. coli MG1655 by expression of cis-trans isomerase (Cti) from Pseudomonas aeruginosa. While the engineered strain was found to have no increase in membrane integrity, a significant decrease in membrane fluidity was observed, meaning that membrane polarization and rigidity were increased by TUFA incorporation. As a result, tolerance to exogenously added octanoic acid and production of octanoic acid were both increased relative to the wild-type strain. This membrane engineering strategy to improve octanoic acid tolerance was found to require fine-tuning of TUFA abundance. Besides improving tolerance and production of carboxylic acids, TUFA production also enabled increased tolerance in E. coli to other bio-products, e.g. alcohols, organic acids, aromatic compounds, a variety of adverse industrial conditions, e.g. low pH, high temperature, and also elevated styrene production, another versatile bio-chemical product. TUFA permitted enhanced growth due to alleviation of bio-product toxicity, demonstrating the general effectiveness of this membrane engineering strategy towards improving strain robustness. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Development of an Ada programming support environment database SEAD (Software Engineering and Ada Database) administration manual

NASA Technical Reports Server (NTRS)

Liaw, Morris; Evesson, Donna

1988-01-01

Software Engineering and Ada Database (SEAD) was developed to provide an information resource to NASA and NASA contractors with respect to Ada-based resources and activities which are available or underway either in NASA or elsewhere in the worldwide Ada community. The sharing of such information will reduce duplication of effort while improving quality in the development of future software systems. SEAD data is organized into five major areas: information regarding education and training resources which are relevant to the life cycle of Ada-based software engineering projects such as those in the Space Station program; research publications relevant to NASA projects such as the Space Station Program and conferences relating to Ada technology; the latest progress reports on Ada projects completed or in progress both within NASA and throughout the free world; Ada compilers and other commercial products that support Ada software development; and reusable Ada components generated both within NASA and from elsewhere in the free world. This classified listing of reusable components shall include descriptions of tools, libraries, and other components of interest to NASA. Sources for the data include technical newletters and periodicals, conference proceedings, the Ada Information Clearinghouse, product vendors, and project sponsors and contractors.

Test Planning Approach and Lessons

NASA Technical Reports Server (NTRS)

Parkinson, Douglas A.; Brown, Kendall K.

2004-01-01

As NASA began technology risk reduction activities and planning for the next generation launch vehicle under the Space Launch Initiative (SLI), now the Next Generation Launch Technology (NGLT) Program, a review of past large liquid rocket engine development programs was performed. The intent of the review was to identify any significant lessons from the development testing programs that could be applied to current and future engine development programs. Because the primary prototype engine in design at the time of this study was the Boeing-Rocketdyne RS-84, the study was slightly biased towards LOX/RP-1 liquid propellant engines. However, the significant lessons identified are universal. It is anticipated that these lessons will serve as a reference for test planning in the Engine Systems Group at Marshall Space Flight Center (MSFC). Towards the end of F-1 and J-2 engine development testing, NASA/MSFC asked Rocketdyne to review those test programs. The result was a document titled, Study to Accelerate Development by Test of a Rocket Engine (R-8099). The "intent (of this study) is to apply this thinking and learning to more efficiently develop rocket engines to high reliability with improved cost effectivenes" Additionally, several other engine programs were reviewed - such as SSME, NSTS, STME, MC-1, and RS-83- to support or refute the R-8099. R-8099 revealed two primary lessons for test planning, which were supported by the other engine development programs. First, engine development programs can benefit from arranging the test program for engine system testing as early as feasible. The best test for determining environments is at the system level, the closest to the operational flight environment. Secondly, the component testing, which tends to be elaborate, should instead be geared towards reducing risk to enable system test. Technical risk can be reduced at the component level, but the design can only be truly verified and validated after engine system testing.

Autonomous Cryogenic Load Operations: Knowledge-Based Autonomous Test Engineer

NASA Technical Reports Server (NTRS)

Schrading, J. Nicolas

2013-01-01

The Knowledge-Based Autonomous Test Engineer (KATE) program has a long history at KSC. Now a part of the Autonomous Cryogenic Load Operations (ACLO) mission, this software system has been sporadically developed over the past 20 years. Originally designed to provide health and status monitoring for a simple water-based fluid system, it was proven to be a capable autonomous test engineer for determining sources of failure in the system. As part of a new goal to provide this same anomaly-detection capability for a complicated cryogenic fluid system, software engineers, physicists, interns and KATE experts are working to upgrade the software capabilities and graphical user interface. Much progress was made during this effort to improve KATE. A display of the entire cryogenic system's graph, with nodes for components and edges for their connections, was added to the KATE software. A searching functionality was added to the new graph display, so that users could easily center their screen on specific components. The GUI was also modified so that it displayed information relevant to the new project goals. In addition, work began on adding new pneumatic and electronic subsystems into the KATE knowledge base, so that it could provide health and status monitoring for those systems. Finally, many fixes for bugs, memory leaks, and memory errors were implemented and the system was moved into a state in which it could be presented to stakeholders. Overall, the KATE system was improved and necessary additional features were added so that a presentation of the program and its functionality in the next few months would be a success.

Autonomous Cryogenic Load Operations: KSC Autonomous Test Engineer

NASA Technical Reports Server (NTRS)

Shrading, Nicholas J.

2012-01-01

The KSC Autonomous Test Engineer (KATE) program has a long history at KSC. Now a part of the Autonomous Cryogenic Load Operations (ACLO) mission, this software system has been sporadically developed over the past 20+ years. Originally designed to provide health and status monitoring for a simple water-based fluid system, it was proven to be a capable autonomous test engineer for determining sources of failure in. the system, As part.of a new goal to provide this same anomaly-detection capability for a complicated cryogenic fluid system, software engineers, physicists, interns and KATE experts are working to upgrade the software capabilities and graphical user interface. Much progress was made during this effort to improve KATE. A display ofthe entire cryogenic system's graph, with nodes for components and edges for their connections, was added to the KATE software. A searching functionality was added to the new graph display, so that users could easily center their screen on specific components. The GUI was also modified so that it displayed information relevant to the new project goals. In addition, work began on adding new pneumatic and electronic subsystems into the KATE knowledgebase, so that it could provide health and status monitoring for those systems. Finally, many fixes for bugs, memory leaks, and memory errors were implemented and the system was moved into a state in which it could be presented to stakeholders. Overall, the KATE system was improved and necessary additional features were added so that a presentation of the program and its functionality in the next few months would be a success.

Sound quality assessment of Diesel combustion noise using in-cylinder pressure components

NASA Astrophysics Data System (ADS)

Payri, F.; Broatch, A.; Margot, X.; Monelletta, L.

2009-01-01

The combustion process in direct injection (DI) Diesel engines is an important source of noise, and it is thus the main reason why end-users could be reluctant to drive vehicles powered with this type of engine. This means that the great potential of Diesel engines for environment preservation—due to their lower consumption and the subsequent reduction of CO2 emissions—may be lost. Moreover, the advanced combustion concepts—e.g. the HCCI (homogeneous charge compression ignition)—developed to comply with forthcoming emissions legislation, while maintaining the efficiency of current engines, are expected to be noisier because they are characterized by a higher amount of premixed combustion. For this reason many efforts have been dedicated by car manufacturers in recent years to reduce the overall level and improve the sound quality of engine noise. Evaluation procedures are required, both for noise levels and sound quality, that may be integrated in the global engine development process in a timely and cost-effective manner. In previous published work, the authors proposed a novel method for the assessment of engine noise level. A similar procedure is applied in this paper to demonstrate the suitability of combustion indicators for the evaluation of engine noise quality. These indicators, which are representative of the peak velocity of fuel burning and the resonance in the combustion chamber, are well correlated with the combustion noise mark obtained from jury testing. Quite good accuracy in the prediction of the engine noise quality has been obtained with the definition of a two-component regression, which also permits the identification of the combustion process features related to the resulting noise quality, so that corrective actions may be proposed.

Retaining minorities in engineering: Assessment of a program prototype

NASA Astrophysics Data System (ADS)

Good, Jennifer Marie (Phillips)

Program assessment is an essential part of healthy program development. Assessment should include multiple considerations, dimensions, and outcomes that match the program's objectives. As a newly formed retention program, the Auburn University Minority Engineering Program, designed to help pre-engineering minority students make the transition into their freshman year of university studies, incorporated evaluation and assessment into all three components of the program (the interactive learning laboratory, critical-thinking workshops, and Sunday-evening tutorials) from the program's inception. If students successfully adapted to the university environment and the demands of the pre-engineering course of study, then retention of minority students in the College of Engineering should improve. Data were gathered on the students involved in the various program components. Students who entered the Minority Engineering Program were pre- and posttested on three standardized subtests (critical thinking, mathematics, and science reasoning) of the Collegiate Assessment of Academic Proficiency. The first-quarter grade-point averages of the students were also gathered to compare their grades to freshman students in previous quarters within the College of Engineering. Qualitative data were also gathered on this same group of students. An analysis of the data revealed that student achievement is affected by involvement in the Minority Engineering Program. Specifically, the first quarter grade point averages of students involved in the program exceeded those of their peers in earlier years of study prior to the program's existence. In addition, mathematics and science reasoning scores on standardized tests increased pre- to postintervention. Comments collected in journals and files also demonstrated use of critical-thinking and problem-solving skills employed by the students. Recommendations for alterations of the program were made based on the outcome of the program evaluation. Further suggestions for research in minority engineering program development and evaluation were also discussed.

Toward Reusable Graphics Components in Ada

DTIC Science & Technology

1993-03-01

Then alternatives for obtaining well- engineered reusable software components were examined. Finally, the alternatives were analyzed, and the most...reusable software components. Chapter 4 describes detailed design and implementation strategies in building a well- engineered reusable set of components in...study. 2.2 The Object-Oriented Paradigm 2.2.1 The Need for Object-Oriented Techniques. Among software engineers the software crisis is a well known

Study of an advanced General Aviation Turbine Engine (GATE)

NASA Technical Reports Server (NTRS)

Gill, J. C.; Short, F. R.; Staton, D. V.; Zolezzi, B. A.; Curry, C. E.; Orelup, M. J.; Vaught, J. M.; Humphrey, J. M.

1979-01-01

The best technology program for a small, economically viable gas turbine engine applicable to the general aviation helicopter and aircraft market for 1985-1990 was studied. Turboshaft and turboprop engines in the 112 to 746 kW (150 to 1000 hp) range and turbofan engines up to 6672 N (1500 lbf) thrust were considered. A good market for new turbine engines was predicted for 1988 providing aircraft are designed to capitalize on the advantages of the turbine engine. Parametric engine families were defined in terms of design and off-design performance, mass, and cost. These were evaluated in aircraft design missions selected to represent important market segments for fixed and rotary-wing applications. Payoff parameters influenced by engine cycle and configuration changes were aircraft gross mass, acquisition cost, total cost of ownership, and cash flow. Significant advantage over a current technology, small gas turbine engines was found especially in cost of ownership and fuel economy for airframes incorporating an air-cooled high-pressure ratio engine. A power class of 373 kW (500 hp) was recommended as the next frontier for technology advance where large improvements in fuel economy and engine mass appear possible through component research and development.

Conceptual design study of an Improved Gas Turbine (IGT) powertrain

NASA Technical Reports Server (NTRS)

Johnson, R. A.

1979-01-01

Design concepts for an improved automotive gas turbine powertrain are discussed. Twenty percent fuel economy improvement (over 1976), competitive costs (initial and life cycle), high reliability/life, low emissions, and noise/safety compliance were among the factors considered. The powertrain selected consists of a two shaft gas turbine engine with variable geometry aerodynamic components and a single disk rotating regenerator. The regenerator disk, gasifier turbine rotor, and several hot section flowpath parts are ceramic. The powertrain utilizes a conventional automatic transmission. The closest competitor was a single shaft turbine engine matched to a continuously variable transmission (CVT). Both candidate powertrain systems were found to be similar in many respects; however, the CVT represented a significant increase in development cost, technical risk, and production start-up costs over the conventional automatic transmission. Installation of the gas turbine powertrain was investigated for a transverse mounted, front wheel drive vehicle.

At a glance: cellular biology for engineers.

PubMed

Khoshmanesh, K; Kouzani, A Z; Nahavandi, S; Baratchi, S; Kanwar, J R

2008-10-01

Engineering contributions have played an important role in the rise and evolution of cellular biology. Engineering technologies have helped biologists to explore the living organisms at cellular and molecular levels, and have created new opportunities to tackle the unsolved biological problems. There is now a growing demand to further expand the role of engineering in cellular biology research. For an engineer to play an effective role in cellular biology, the first essential step is to understand the cells and their components. However, the stumbling block of this step is to comprehend the information given in the cellular biology literature because it best suits the readers with a biological background. This paper aims to overcome this bottleneck by describing the human cell components as micro-plants that form cells as micro-bio-factories. This concept can accelerate the engineers' comprehension of the subject. In this paper, first the structure and function of different cell components are described. In addition, the engineering attempts to mimic various cell components through numerical modelling or physical implementation are highlighted. Next, the interaction of different cell components that facilitate complicated chemical processes, such as energy generation and protein synthesis, are described. These complex interactions are translated into simple flow diagrams, generally used by engineers to represent multi-component processes.

Heavy Vehicle Propulsion System Materials Program Semiannual Progress Report for April 2000 Through September 2000

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

Johnson, DR

2000-12-11

The purpose of the Heavy Vehicle Propulsion System Materials Program is the development of materials: ceramics, intermetallics, metal alloys, and metal and ceramic coatings, to support the dieselization of class 1-3 trucks to realize a 35% fuel-economy improvement over current gasoline-fueled trucks and to support commercialization of fuel-flexible LE-55 low-emissions, high-efficiency diesel engines for class 7-8 trucks. The Office of Transportation Technologies, Office of Heavy Vehicle Technologies (OTT OHVT) has an active program to develop the technology for advantages LE-55 diesel engines with 55% efficiency and low emissions levels of 2.0 g/bhp-h NOx and 0.05 g/bhp-h particulates. The goal ismore » also for the LE-55 engine to run on natural gas with efficiency approaching that of diesel fuel. The LE-55 program is being completed in FY 1997 and, after approximately 10 years of effort, has largely met the program goals of 55% efficiency and low emissions. However, the commercialization of the LE-55 technology requires more durable materials than those that have been used to demonstrate the goals. Heavy Vehicle Propulsion System Materials will, in concert with the heavy duty diesel engine companies, develop the durable materials required to commercialize the LE-55 technologies. OTT OHVT also recognizes a significant opportunity for reduction in petroleum consumption by dieselization of pickup trucks, vans, and sport utility vehicles. Application of the diesel engine to class 1, 2, and 3 trucks is expected to yield a 35% increase in fuel economy per vehicle. The foremost barrier to diesel use in this market is emission control. Once an engine is made certifiable, subsequent challenges will be in cost; noise, vibration, and harshness (NVH); and performance. The design of advanced components for high-efficiency diesel engines has, in some cases, pushed the performance envelope for materials of construction past the point of reliable operation. Higher mechanical and tribological stresses and higher temperatures of advanced designs limit the engine designer; advanced materials allow the design of components that may operate reliably at higher stresses and temperatures, thus enabling more efficient engine designs. Advanced materials also offer the opportunity to improve the emissions, NVH, and performance of diesel engines for pickup trucks, vans, and sport utility vehicles.« less

Controlling exhaust gas recirculation

DOEpatents

Zurlo, James Richard [Madison, WI; Konkle, Kevin Paul [West Bend, WI; May, Andrew [Milwaukee, WI

2012-01-31

In controlling an engine, an amount of an intake charge provided, during operation of the engine, to a combustion chamber of the engine is determined. The intake charge includes an air component, a fuel component and a diluent component. An amount of the air component of the intake charge is determined. An amount of the diluent component of the intake charge is determined utilizing the amount of the intake charge, the amount of the air component and, in some instances, the amount of the fuel component. An amount of a diluent supplied to the intake charge is adjusted based at least in part on the determined amount of diluent component of the intake charge.

Dragonfly: strengthening programming skills by building a game engine from scratch

NASA Astrophysics Data System (ADS)

Claypool, Mark

2013-06-01

Computer game development has been shown to be an effective hook for motivating students to learn both introductory and advanced computer science topics. While games can be made from scratch, to simplify the programming required game development often uses game engines that handle complicated or frequently used components of the game. These game engines present the opportunity to strengthen programming skills and expose students to a range of fundamental computer science topics. While educational efforts have been effective in using game engines to improve computer science education, there have been no published papers describing and evaluating students building a game engine from scratch as part of their course work. This paper presents the Dragonfly-approach in which students build a fully functional game engine from scratch and make a game using their engine as part of a junior-level course. Details on the programming projects are presented, as well as an evaluation of the results from two offerings that used Dragonfly. Student performance on the projects as well as student assessments demonstrates the efficacy of having students build a game engine from scratch in strengthening their programming skills.

Ceramic Composite Development for Gas Turbine Engine Hot Section Components

NASA Technical Reports Server (NTRS)

DiCarlo, James A.; VANrOODE, mARK

2006-01-01

The development of ceramic materials for incorporation into the hot section of gas turbine engines has been ongoing for about fifty years. Researchers have designed, developed, and tested ceramic gas turbine components in rigs and engines for automotive, aero-propulsion, industrial, and utility power applications. Today, primarily because of materials limitations and/or economic factors, major challenges still remain for the implementation of ceramic components in gas turbines. For example, because of low fracture toughness, monolithic ceramics continue to suffer from the risk of failure due to unknown extrinsic damage events during engine service. On the other hand, ceramic matrix composites (CMC) with their ability to display much higher damage tolerance appear to be the materials of choice for current and future engine components. The objective of this paper is to briefly review the design and property status of CMC materials for implementation within the combustor and turbine sections for gas turbine engine applications. It is shown that although CMC systems have advanced significantly in thermo-structural performance within recent years, certain challenges still exist in terms of producibility, design, and affordability for commercial CMC turbine components. Nevertheless, there exist some recent successful efforts for prototype CMC components within different engine types.

Application of Analytic Hierarchy Process (AHP) in the analysis of the fuel efficiency in the automobile industry with the utilization of Natural Fiber Polymer Composites (NFPC)

NASA Astrophysics Data System (ADS)

Jayamani, E.; Perera, D. S.; Soon, K. H.; Bakri, M. K. B.

2017-04-01

A systematic method of material analysis aiming for fuel efficiency improvement with the utilization of natural fiber reinforced polymer matrix composites in the automobile industry is proposed. A multi-factor based decision criteria with Analytical Hierarchy Process (AHP) was used and executed through MATLAB to achieve improved fuel efficiency through the weight reduction of vehicular components by effective comparison between two engine hood designs. The reduction was simulated by utilizing natural fiber polymer composites with thermoplastic polypropylene (PP) as the matrix polymer and benchmarked against a synthetic based composite component. Results showed that PP with 35% of flax fiber loading achieved a 0.4% improvement in fuel efficiency, and it was the highest among the 27 candidate fibers.

Component-specific modeling. [jet engine hot section components

NASA Technical Reports Server (NTRS)

Mcknight, R. L.; Maffeo, R. J.; Tipton, M. T.; Weber, G.

1992-01-01

Accomplishments are described for a 3 year program to develop methodology for component-specific modeling of aircraft hot section components (turbine blades, turbine vanes, and burner liners). These accomplishments include: (1) engine thermodynamic and mission models, (2) geometry model generators, (3) remeshing, (4) specialty three-dimensional inelastic structural analysis, (5) computationally efficient solvers, (6) adaptive solution strategies, (7) engine performance parameters/component response variables decomposition and synthesis, (8) integrated software architecture and development, and (9) validation cases for software developed.

Simulation Enabled Safeguards Assessment Methodology

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

Robert Bean; Trond Bjornard; Thomas Larson

2007-09-01

It is expected that nuclear energy will be a significant component of future supplies. New facilities, operating under a strengthened international nonproliferation regime will be needed. There is good reason to believe virtual engineering applied to the facility design, as well as to the safeguards system design will reduce total project cost and improve efficiency in the design cycle. Simulation Enabled Safeguards Assessment MEthodology (SESAME) has been developed as a software package to provide this capability for nuclear reprocessing facilities. The software architecture is specifically designed for distributed computing, collaborative design efforts, and modular construction to allow step improvements inmore » functionality. Drag and drop wireframe construction allows the user to select the desired components from a component warehouse, render the system for 3D visualization, and, linked to a set of physics libraries and/or computational codes, conduct process evaluations of the system they have designed.« less

Qualitative Importance Measures of Systems Components - A New Approach and Its Applications

NASA Astrophysics Data System (ADS)

Chybowski, Leszek; Gawdzińska, Katarzyna; Wiśnicki, Bogusz

2016-12-01

The paper presents an improved methodology of analysing the qualitative importance of components in the functional and reliability structures of the system. We present basic importance measures, i.e. the Birnbaum's structural measure, the order of the smallest minimal cut-set, the repetition count of an i-th event in the Fault Tree and the streams measure. A subsystem of circulation pumps and fuel heaters in the main engine fuel supply system of a container vessel illustrates the qualitative importance analysis. We constructed a functional model and a Fault Tree which we analysed using qualitative measures. Additionally, we compared the calculated measures and introduced corrected measures as a tool for improving the analysis. We proposed scaled measures and a common measure taking into account the location of the component in the reliability and functional structures. Finally, we proposed an area where the measures could be applied.

Progress in SiC/SiC Ceramic Composite Development for Gas Turbine Hot-Section Components under NASA EPM and UEET Programs

NASA Technical Reports Server (NTRS)

DiCarlo, J. A.; Yun, Hee Mann; Morscher, Gregory N.; Bhatt, Ramakrishna T.

2002-01-01

The successful application of ceramic matrix composites as hot-section components in advanced gas turbine engines will require the development of constituent materials and processes that can provide the material systems with the key thermostructural properties required for long-term component service. Much initial progress in identifying these materials and processes was made under the former NASA Enabling Propulsion Materials Program using stoichiometric Sylramic (trademark) silicon-carbide (SiC) fibers, 2D (two dimensional)-woven fiber architectures, chemically vapor-infiltrated (CVI) BN fiber coatings (interphases), and SiC-based matrices containing CVI SiC interphase over-coatings, slurry-infiltrated SiC particulate, and melt-infiltrated (MI) silicon. The objective of this paper is to discuss the property benefits of this SiC/SiC composite system for high-temperature engine components and to elaborate on further progress in SiC/SiC development made under the new NASA Ultra Efficient Engine Technology Program. This progress stems from the recent development of advanced constituent materials and manufacturing processes, including specific treatments at NASA that improve the creep, rupture, and environmental resistance of the Sylramic fiber as well as the thermal conductivity and creep resistance of the CVI SiC over-coatings. Also discussed are recent observations concerning the detrimental effects of inadvertent carbon in the fiber-BN interfacial region and the beneficial effects of certain 2D-architectures for thin-walled SiC/SiC panels.

On2broker: Semantic-Based Access to Information Sources at the WWW.

ERIC Educational Resources Information Center

Fensel, Dieter; Angele, Jurgen; Decker, Stefan; Erdmann, Michael; Schnurr, Hans-Peter; Staab, Steffen; Studer, Rudi; Witt, Andreas

On2broker provides brokering services to improve access to heterogeneous, distributed, and semistructured information sources as they are presented in the World Wide Web. It relies on the use of ontologies to make explicit the semantics of Web pages. This paper discusses the general architecture and main components (i.e., query engine, information…

Studying interregional wildland fire engine assignments for large fire suppression

Treesearch

Erin J. Belval; Yu Wei; David E. Calkin; Crystal S. Stonesifer; Matthew P. Thompson; John R. Tipton

2017-01-01

One crucial component of large fire response in the United States (US) is the sharing of wildland firefighting resources between regions: resources from regions experiencing low fire activity supplement resources in regions experiencing high fire activity. An important step towards improving the efficiency of resource sharing and related policies is to develop a better...

Multiphysics Code Demonstrated for Propulsion Applications

NASA Technical Reports Server (NTRS)

Lawrence, Charles; Melis, Matthew E.

1998-01-01

The utility of multidisciplinary analysis tools for aeropropulsion applications is being investigated at the NASA Lewis Research Center. The goal of this project is to apply Spectrum, a multiphysics code developed by Centric Engineering Systems, Inc., to simulate multidisciplinary effects in turbomachinery components. Many engineering problems today involve detailed computer analyses to predict the thermal, aerodynamic, and structural response of a mechanical system as it undergoes service loading. Analysis of aerospace structures generally requires attention in all three disciplinary areas to adequately predict component service behavior, and in many cases, the results from one discipline substantially affect the outcome of the other two. There are numerous computer codes currently available in the engineering community to perform such analyses in each of these disciplines. Many of these codes are developed and used in-house by a given organization, and many are commercially available. However, few, if any, of these codes are designed specifically for multidisciplinary analyses. The Spectrum code has been developed for performing fully coupled fluid, thermal, and structural analyses on a mechanical system with a single simulation that accounts for all simultaneous interactions, thus eliminating the requirement for running a large number of sequential, separate, disciplinary analyses. The Spectrum code has a true multiphysics analysis capability, which improves analysis efficiency as well as accuracy. Centric Engineering, Inc., working with a team of Lewis and AlliedSignal Engines engineers, has been evaluating Spectrum for a variety of propulsion applications including disk quenching, drum cavity flow, aeromechanical simulations, and a centrifugal compressor flow simulation.

Mathematical modeling of control system for the experimental steam generator

NASA Astrophysics Data System (ADS)

Podlasek, Szymon; Lalik, Krzysztof; Filipowicz, Mariusz; Sornek, Krzysztof; Kupski, Robert; Raś, Anita

2016-03-01

A steam generator is an essential unit of each cogeneration system using steam machines. Currently one of the cheapest ways of the steam generation can be application of old steam generators came from army surplus store. They have relatively simple construction and in case of not so exploited units - quite good general conditions, and functionality of mechanical components. By contrast, electrical components and control systems (mostly based on relay automatics) are definitely obsolete. It is not possible to use such units with cooperation of steam bus or with steam engines. In particular, there is no possibility for automatically adjustment of the pressure and the temperature of the generated steam supplying steam engines. Such adjustment is necessary in case of variation of a generator load. The paper is devoted to description of improvement of an exemplary unit together with construction of the measurement-control system based on a PLC. The aim was to enable for communication between the steam generator and controllers of the steam bus and steam engines in order to construction of a complete, fully autonomic and maintenance-free microcogeneration system.

Production of Diesel Engine Turbocharger Turbine from Low Cost Titanium Powder

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

Muth, T. R.; Mayer, R.

2012-05-04

Turbochargers in commercial turbo-diesel engines are multi-material systems where usually the compressor rotor is made of aluminum or titanium based material and the turbine rotor is made of either a nickel based superalloy or titanium, designed to operate under the harsh exhaust gas conditions. The use of cast titanium in the turbine section has been used by Cummins Turbo Technologies since 1997. Having the benefit of a lower mass than the superalloy based turbines; higher turbine speeds in a more compact design can be achieved with titanium. In an effort to improve the cost model, and develop an industrial supplymore » of titanium componentry that is more stable than the traditional aerospace based supply chain, the Contractor has developed component manufacturing schemes that use economical Armstrong titanium and titanium alloy powders and MgR-HDH powders. Those manufacturing schemes can be applied to compressor and turbine rotor components for diesel engine applications with the potential of providing a reliable supply of titanium componentry with a cost and performance advantage over cast titanium.« less

Furnace Cyclic Oxidation Behavior of Multi-Component Low Conductivity Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Nesbitt, James A.; Barrett, Charles A.; McCue, Terry R.; Miller, Robert A.

2004-01-01

Ceramic thermal barrier coatings will play an increasingly important role in advanced gas turbine engines because of their ability to further increase engine operating temperatures and reduce cooling, thus helping achieve future engine low emission, high efficiency and improved reliability goals. Advanced multi-component zirconia-based thermal barrier coatings are being developed using an oxide defect clustering design approach to achieve the required coating low thermal conductivity and high temperature stability. Although the new composition coatings were not yet optimized for cyclic durability, an initial durability screening of the candidate coating materials was conducted using conventional furnace cyclic oxidation tests. In this paper, furnace cyclic oxidation behavior of plasma-sprayed zirconia-based defect cluster thermal barrier coatings was investigated at 1163 C using 45 min hot cycles. The ceramic coating failure mechanisms were studied using scanning electron microscopy (SEM) combined with X-ray diffraction (XRD) phase analysis after the furnace tests. The coating cyclic lifetime is also discussed in relation to coating processing, phase structures, dopant concentration, and other thermo-physical properties.

Design and characterization of a biodegradable composite scaffold for ligament tissue engineering.

PubMed

Hayami, James W S; Surrao, Denver C; Waldman, Stephen D; Amsden, Brian G

2010-03-15

Herein we report on the development and characterization of a biodegradable composite scaffold for ligament tissue engineering based on the fundamental morphological features of the native ligament. An aligned fibrous component was used to mimic the fibrous collagen network and a hydrogel component to mimic the proteoglycan-water matrix of the ligament. The composite scaffold was constructed from cell-adherent, base-etched, electrospun poly(epsilon-caprolactone-co-D,L-lactide) (PCLDLLA) fibers embedded in a noncell-adherent photocrosslinked N-methacrylated glycol chitosan (MGC) hydrogel seeded with primary ligament fibroblasts. Base etching improved cellular adhesion to the PCLDLLA material. Cells within the MGC hydrogel remained viable (72 +/- 4%) during the 4-week culture period. Immunohistochemistry staining revealed ligament ECM markers collagen type I, collagen type III, and decorin organizing and accumulating along the PCLDLLA fibers within the composite scaffolds. On the basis of these results, it was determined that the composite scaffold design was a viable alternative to the current approaches used for ligament tissue engineering and merits further study. (c) 2009 Wiley Periodicals, Inc.

Simplified Ion Thruster Xenon Feed System for NASA Science Missions

NASA Technical Reports Server (NTRS)

Snyder, John Steven; Randolph, Thomas M.; Hofer, Richard R.; Goebel, Dan M.

2009-01-01

The successful implementation of ion thruster technology on the Deep Space 1 technology demonstration mission paved the way for its first use on the Dawn science mission, which launched in September 2007. Both Deep Space 1 and Dawn used a "bang-bang" xenon feed system which has proven to be highly successful. This type of feed system, however, is complex with many parts and requires a significant amount of engineering work for architecture changes. A simplified feed system, with fewer parts and less engineering work for architecture changes, is desirable to reduce the feed system cost to future missions. An attractive new path for ion thruster feed systems is based on new components developed by industry in support of commercial applications of electric propulsion systems. For example, since the launch of Deep Space 1 tens of mechanical xenon pressure regulators have successfully flown on commercial spacecraft using electric propulsion. In addition, active proportional flow controllers have flown on the Hall-thruster-equipped Tacsat-2, are flying on the ion thruster GOCE mission, and will fly next year on the Advanced EHF spacecraft. This present paper briefly reviews the Dawn xenon feed system and those implemented on other xenon electric propulsion flight missions. A simplified feed system architecture is presented that is based on assembling flight-qualified components in a manner that will reduce non-recurring engineering associated with propulsion system architecture changes, and is compared to the NASA Dawn standard. The simplified feed system includes, compared to Dawn, passive high-pressure regulation, a reduced part count, reduced complexity due to cross-strapping, and reduced non-recurring engineering work required for feed system changes. A demonstration feed system was assembled using flight-like components and used to operate a laboratory NSTAR-class ion engine. Feed system components integrated into a single-string architecture successfully operated the engine over the entire NSTAR throttle range over a series of tests. Flow rates were very stable with variations of at most 0.2%, and transition times between throttle levels were typically 90 seconds or less with a maximum of 200 seconds, both significant improvements over the Dawn bang-bang feed system.

Preparing aircraft propulsion for a new era in energy and the environment

NASA Technical Reports Server (NTRS)

Stewart, W. L.; Nored, D. L.; Grobman, J. S.; Feiler, C. E.; Petrash, D. A.

1980-01-01

Improving fuel efficiency, new sources of jet fuel, and noise and emission control are subjects of NASA's aeronautics program. Projects aimed at attaining a 5% fuel savings for existing engines and a 13-22% savings for the next generation of turbofan engines using advanced components, and establishing a basis for turboprop-powered commercial air transports with 30-40% savings over conventional turbofan aircraft at comparable speeds and altitudes, are discussed. Fuel sources are considered in terms of reduced hydrogen and higher aromatic contents and resultant higher liner temperatures, and attention is given to lean burning, improved fuel atomization, higher freezing-point fuel, and deriving jet fuel from shale oil or coal. Noise sources including the fan, turbine, combustion process, and flow over internal struts, and attenuation using acoustic treatment, are discussed, while near-term reduction of polluting gaseous emissions at both low and high power, and far-term defining of the minimum gaseous-pollutant levels possible from turbine engines are also under study.

Ceramic automotive Stirling engine program

NASA Technical Reports Server (NTRS)

1986-01-01

The Ceramic Automotive Stirling Engine Program evaluated the application of advanced ceramic materials to an automotive Stirling engine. The objective of the program was to evaluate the technical feasibility of utilizing advanced ceramics to increase peak engine operating temperature, and to evaluate the performance benefits of such an increase. Manufacturing cost estimates were also developed for various ceramic engine components and compared with conventional metallic engine component costs.

Automotive Stirling engine development program

NASA Technical Reports Server (NTRS)

Farrell, R.; Hindes, C.; Battista, R.; Connelly, M.; Cronin, M.; Howarth, R.; Donahue, A.; Slate, E.; Stotts, R.; Lacy, R.

1988-01-01

The study of high power kinematic Stirling engines for transportation use, testing of Mod I and Mod II Stirling engines, and component development activities are summarized. Mod II development testing was performed to complete the development of the basic engine and begin characterization of performance. Mod I engines were used for Mod II component development and to obtain independent party (U.S. Air Force) evaluation of Stirling engine vehicle performance.

VCE testbed program planning and definition study

NASA Technical Reports Server (NTRS)

Westmoreland, J. S.; Godston, J.

1978-01-01

The flight definition of the Variable Stream Control Engine (VSCE) was updated to reflect design improvements in the two key components: (1) the low emissions duct burner, and (2) the coannular exhaust nozzle. The testbed design was defined and plans for the overall program were formulated. The effect of these improvements was evaluated for performance, emissions, noise, weight, and length. For experimental large scale testing of the duct burner and coannular nozzle, a design definition of the VCE testbed configuration was made. This included selecting the core engine, determining instrumentation requirements, and selecting the test facilities, in addition to defining control system and assembly requirements. Plans for a comprehensive test program to demonstrate the duct burner and nozzle technologies were formulated. The plans include both aeroacoustic and emissions testing.

Detailed Post-Soft Impact Progressive Damage Assessment for Hybrid Structure Jet Engines

NASA Technical Reports Server (NTRS)

Siddens, Aaron; Bayandor, Javid; Celestina, Mark L.

2014-01-01

Currently, certification of engine designs for resistance to bird strike is reliant on physical tests. Predictive modeling of engine structural damage has mostly been limited to evaluation of individual forward section components, such as fan blades within a fixed frame of reference, to direct impact with a bird. Such models must be extended to include interactions among engine components under operating conditions to evaluate the full extent of engine damage. This paper presents the results of a study aim to develop a methodology for evaluating bird strike damage in advanced propulsion systems incorporating hybrid composite/metal structures. The initial degradation and failure of individual fan blades struck by a bird were investigated. Subsequent damage to other fan blades and engine components due to resultant violent fan assembly vibrations and fragmentation was further evaluated. Various modeling parameters for the bird and engine components were investigated to determine guidelines for accurately capturing initial damage and progressive failure of engine components. Then, a novel hybrid structure modeling approach was investigated and incorporated into the crashworthiness methodology. Such a tool is invaluable to the process of design, development, and certification of future advanced propulsion systems.

Innovative Adaptive Control Method Demonstrated for Active Suppression of Instabilities in Engine Combustors

NASA Technical Reports Server (NTRS)

Kopasakis, George

2005-01-01

This year, an improved adaptive-feedback control method was demonstrated that suppresses thermoacoustic instabilities in a liquid-fueled combustor of a type used in aircraft engines. Extensive research has been done to develop lean-burning (low fuel-to-air ratio) combustors that can reduce emissions throughout the mission cycle to reduce the environmental impact of aerospace propulsion systems. However, these lean-burning combustors are susceptible to thermoacoustic instabilities (high-frequency pressure waves), which can fatigue combustor components and even downstream turbine blades. This can significantly decrease the safe operating life of the combustor and turbine. Thus, suppressing the thermoacoustic combustor instabilities is an enabling technology for meeting the low-emission goals of the NASA Ultra-Efficient Engine Technology (UEET) Project.

Power processing and control requirements of dispersed solar thermal electric generation systems

NASA Technical Reports Server (NTRS)

Das, R. L.

1980-01-01

Power Processing and Control requirements of Dispersed Receiver Solar Thermal Electric Generation Systems are presented. Kinematic Stirling Engines, Brayton Engines and Rankine Engines are considered as prime movers. Various types of generators are considered for ac and dc link generations. It is found that ac-ac Power Conversion is not suitable for implementation at this time. It is also found that ac-dc-ac Power Conversion with a large central inverter is more efficient than ac-dc-ac Power Conversion using small dispersed inverters. Ac-link solar thermal electric plants face potential stability and synchronization problems. Research and development efforts are needed in improving component performance characteristics and generation efficiency to make Solar Thermal Electric Generation economically attractive.

Energy efficient engine component development and integration program

NASA Technical Reports Server (NTRS)

1980-01-01

The design of an energy efficient commercial turbofan engine is examined with emphasis on lower fuel consumption and operating costs. Propulsion system performance, emission standards, and noise reduction are also investigated. A detailed design analysis of the engine/aircraft configuration, engine components, and core engine is presented along with an evaluation of the technology and testing involved.

New Material Development for Surface Layer and Surface Technology in Tribology Science to Improve Energy Efficiency

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

Ismail, R., E-mail: rifky-mec@yahoo.com; Tauviqirrahman, M., E-mail: rifky-mec@yahoo.com; Laboratory for Surface Technology and Tribology, Faculty of Engineering Technology, University of Twente, Enschede

This paper reviews the development of new material and surface technology in tribology and its contribution to energy efficiency. Two examples of the economic benefits, resulted from the optimum tribology in the transportation sector and the manufacturing industry are discussed. The new materials are proposed to modify the surface property by laminating the bulk material with thin layer/coating. Under a suitable condition, the thin layer on a surface can provide a combination of good wear, a low friction and corrosion resistance for the mechanical components. The innovation in layer technology results molybdenum disulfide (MoS2), diamond like carbon (DLC), cubic boronmore » nitride (CBN) and diamond which perform satisfactory outcome. The application of the metallic coatings to carbon fibre reinforced polymer matrix composites (CFRP) has the capacity to provide considerable weight and power savings for many engineering components. The green material for lubricant and additives such as the use of sunflower oil which possesses good oxidation resistance and the use of mallee leaves as bio‐degradable solvent are used to answer the demand of the environmentally friendly material with good performance. The tribology research implementation for energy efficiency also touches the simple things around us such as: erasing the laser‐print in a paper with different abrasion techniques. For the technology in the engineering surface, the consideration for generating the suitable surface of the components in running‐in period has been discussed in order to prolong the components life and reduce the machine downtime. The conclusion, tribology can result in reducing manufacturing time, reducing the maintenance requirements, prolonging the service interval, improving durability, reliability and mechanical components life, and reducing harmful exhaust emission and waste. All of these advantages will increase the energy efficiency and the economic benefits.« less

New Material Development for Surface Layer and Surface Technology in Tribology Science to Improve Energy Efficiency

NASA Astrophysics Data System (ADS)

Ismail, R.; Tauviqirrahman, M.; Jamari, Jamari; Schipper, D. J.

2009-09-01

This paper reviews the development of new material and surface technology in tribology and its contribution to energy efficiency. Two examples of the economic benefits, resulted from the optimum tribology in the transportation sector and the manufacturing industry are discussed. The new materials are proposed to modify the surface property by laminating the bulk material with thin layer/coating. Under a suitable condition, the thin layer on a surface can provide a combination of good wear, a low friction and corrosion resistance for the mechanical components. The innovation in layer technology results molybdenum disulfide (MoS2), diamond like carbon (DLC), cubic boron nitride (CBN) and diamond which perform satisfactory outcome. The application of the metallic coatings to carbon fibre reinforced polymer matrix composites (CFRP) has the capacity to provide considerable weight and power savings for many engineering components. The green material for lubricant and additives such as the use of sunflower oil which possesses good oxidation resistance and the use of mallee leaves as bio-degradable solvent are used to answer the demand of the environmentally friendly material with good performance. The tribology research implementation for energy efficiency also touches the simple things around us such as: erasing the laser-print in a paper with different abrasion techniques. For the technology in the engineering surface, the consideration for generating the suitable surface of the components in running-in period has been discussed in order to prolong the components life and reduce the machine downtime. The conclusion, tribology can result in reducing manufacturing time, reducing the maintenance requirements, prolonging the service interval, improving durability, reliability and mechanical components life, and reducing harmful exhaust emission and waste. All of these advantages will increase the energy efficiency and the economic benefits.

Detector sustainability improvements at LCLS

NASA Astrophysics Data System (ADS)

Browne, Michael C.; Carini, Gabriella; DePonte, Daniel P.; Galtier, Eric C.; Hart, Philip A.; Koralek, J. D.; Mitra, Ankush; Nakahara, Kazutaka

2017-06-01

The Linac Coherent Light Source (LCLS) poses a number of daunting and often unusual challenges to maintaining X-ray detectors, such as proximity to liquid-sample injectors, complex setups with moving components, intense X-ray and optical laser light, and Electromagnetic Pulse (EMP). The Detector and Sample Environment departments at LCLS are developing an array of engineering, monitoring, and administrative controls solutions to better address these issues. These include injector improvements and monitoring methods, fast online damage recognition algorithms, EMP mapping and protection, actively cooled filters, and more.

Analysis, design, fabrication and testing of an optical tip clearance sensor. [turbocompressor blade tips

NASA Technical Reports Server (NTRS)

Poppel, G. L.; Marple, D. T. F.; Kingsley, J. D.

1981-01-01

Analyses and the design, fabrication, and testing of an optical tip clearance sensor with intended application in aircraft propulsion control systems are reported. The design of a sensor test rig, evaluation of optical sensor components at elevated temperatures, sensor design principles, sensor test results at room temperature, and estimations of sensor accuracy at temperatures of an aircraft engine environment are discussed. Room temperature testing indicated possible measurement accuracies of less than 12.7 microns (0.5 mils). Ways to improve performance at engine operating temperatures are recommended. The potential of this tip clearance sensor is assessed.

Design and evaluation of experimental ceramic automobile thermal reactors

NASA Technical Reports Server (NTRS)

Stone, P. L.; Blankenship, C. P.

1974-01-01

The paper summarizes the results obtained in an exploratory evaluation of ceramics for automobile thermal reactors. Candidate ceramic materials were evaluated in several reactor designs using both engine dynamometer and vehicle road tests. Silicon carbide contained in a corrugated metal support structure exhibited the best performance, lasting 1100 hours in engine dynamometer tests and for more than 38,600 kilimeters (24,000 miles) in vehicle road tests. Although reactors containing glass-ceramic components did not perform as well as silicon carbide, the glass-ceramics still offer good potential for reactor use with improved reactor designs.

Design and evaluation of experimental ceramic automobile thermal reactors

NASA Technical Reports Server (NTRS)

Stone, P. L.; Blankenship, C. P.

1974-01-01

The results obtained in an exploratory evaluation of ceramics for automobile thermal reactors are summarized. Candidate ceramic materials were evaluated in several reactor designs by using both engine-dynamometer and vehicle road tests. Silicon carbide contained in a corrugated-metal support structure exhibited the best performance, lasting 1100 hr in engine-dynamometer tests and more than 38,600 km (24000 miles) in vehicle road tests. Although reactors containing glass-ceramic components did not perform as well as those containing silicon carbide, the glass-ceramics still offer good potential for reactor use with improved reactor designs.

Powder Injection Molding of Ceramic Engine Components for Transportation

NASA Astrophysics Data System (ADS)

Lenz, Juergen; Enneti, Ravi K.; Onbattuvelli, Valmikanathan; Kate, Kunal; Martin, Renee; Atre, Sundar

2012-03-01

Silicon nitride has been the favored material for manufacturing high-efficiency engine components for transportation due to its high temperature stability, good wear resistance, excellent corrosion resistance, thermal shock resistance, and low density. The use of silicon nitride in engine components greatly depends on the ability to fabricate near net-shape components economically. The absence of a material database for design and simulation has further restricted the engineering community in developing parts from silicon nitride. In this paper, the design and manufacturability of silicon nitride engine rotors for unmanned aerial vehicles by the injection molding process are discussed. The feedstock material property data obtained from experiments were used to simulate the flow of the material during injection molding. The areas susceptible to the formation of defects during the injection molding process of the engine component were identified from the simulations. A test sample was successfully injection molded using the feedstock and sintered to 99% density without formation of significant observable defects.

Case Studies of Fatigue Life Improvement Using Low Plasticity Burnishing in Gas Turbine Engine Applications

NASA Technical Reports Server (NTRS)

Prevey, Paul S.; Shepard, Michael; Ravindranath, Ravi A.; Gabb, Timothy

2003-01-01

Surface enhancement technologies such as shot peening, laser shock peening (LSP), and low plasticity burnishing (LPB) can provide substantial fatigue life improvement. However, to be effective, the compressive residual stresses that increase fatigue strength must be retained in service. For successful integration into turbine design, the process must be affordable and compatible with the manufacturing environment. LPB provides thermally stable compression of comparable magnitude and even greater depth than other methods, and can be performed in conventional machine shop environments on CNC machine tools. LPB provides a means to extend the fatigue lives of both new and legacy aircraft engines and ground-based turbines. Improving fatigue performance by introducing deep stable layers of compressive residual stress avoids the generally cost prohibitive alternative of modifying either material or design. The X-ray diffraction based background studies of thermal and mechanical stability of surface enhancement techniques are briefly reviewed, demonstrating the importance of minimizing cold work. The LPB process, tooling, and control systems are described. An overview of current research programs conducted for engine OEMs and the military to apply LPB to a variety of engine and aging aircraft components are presented. Fatigue performance and residual stress data developed to date for several case studies are presented including: * The effect of LPB on the fatigue performance of the nickel based super alloy IN718, showing fatigue benefit of thermal stability at engine temperatures. * An order of magnitude improvement in damage tolerance of LPB processed Ti-6-4 fan blade leading edges. * Elimination of the fretting fatigue debit for Ti-6-4 with prior LPB. * Corrosion fatigue mitigation with LPB in Carpenter 450 steel. *Damage tolerance improvement in 17-4PH steel. Where appropriate, the performance of LPB is compared to conventional shot peening after exposure to engine operating temperatures.

14 CFR 27.1189 - Shutoff means.

Code of Federal Regulations, 2010 CFR

2010-01-01

...— (1) Lines, fittings, and components forming an intergral part of an engine; (2) For oil systems for which all components of the system, including oil tanks, are fireproof or located in areas not subject to engine fire conditions; and (3) For reciprocating engine installations only, engine oil system...

Turbomachine Sealing and Secondary Flows - Part 3. Part 3; Review of Power-Stream Support, Unsteady Flow Systems, Seal and Disk Cavity Flows, Engine Externals, and Life and Reliability Issues

NASA Technical Reports Server (NTRS)

Hendricks, R. C.; Steinetz, B. M.; Zaretsky, E. V.; Athavale, M. M.; Przekwas, A. J.

2004-01-01

The issues and components supporting the engine power stream are reviewed. It is essential that companies pay close attention to engine sealing issues, particularly on the high-pressure spool or high-pressure pumps. Small changes in these systems are reflected throughout the entire engine. Although cavity, platform, and tip sealing are complex and have a significant effect on component and engine performance, computational tools (e.g., NASA-developed INDSEAL, SCISEAL, and ADPAC) are available to help guide the designer and the experimenter. Gas turbine engine and rocket engine externals must all function efficiently with a high degree of reliability in order for the engine to run but often receive little attention until they malfunction. Within the open literature statistically significant data for critical engine components are virtually nonexistent; the classic approach is deterministic. Studies show that variations with loading can have a significant effect on component performance and life. Without validation data they are just studies. These variations and deficits in statistical databases require immediate attention.

Progress with variable cycle engines

NASA Technical Reports Server (NTRS)

Westmoreland, J. S.

1980-01-01

The evaluation of components of an advanced propulsion system for a future supersonic cruise vehicle is discussed. These components, a high performance duct burner for thrust augmentation and a low jet noise coannular exhaust nozzle, are part of the variable stream control engine. An experimental test program involving both isolated component and complete engine tests was conducted for the high performance, low emissions duct burner with excellent results. Nozzle model tests were completed which substantiate the inherent jet noise benefit associated with the unique velocity profile possible of a coannular exhaust nozzle system on a variable stream control engine. Additional nozzle model performance tests have established high thrust efficiency levels at takeoff and supersonic cruise for this nozzle system. Large scale testing of these two critical components is conducted using an F100 engine as the testbed for simulating the variable stream control engine.

Low-Engine-Friction Technology for Advanced Natural-Gas Reciprocating Engines

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

Victor Wong; Tian Tian; G. Smedley

This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston and piston ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and wear. An iterative process of simulation, experimentation and analysis has been followed towards achieving the goal of demonstrating a complete optimized low-friction engine system. In this program, a detailed set of piston and piston-ring dynamic and friction models have been adapted and applied that illustrate the fundamental relationships among mechanical, surface/material and lubricant design parameters and friction losses. Demonstration of low-friction ring-pack designs in the Waukeshamore » VGF 18GL engine confirmed ring-pack friction reduction of 30-40%, which translates to total engine FEMP (friction mean effective pressure) reduction of 7-10% from the baseline configuration without significantly increasing oil consumption or blow-by flow. The study on surface textures, including roughness characteristics, cross hatch patterns, dimples and grooves have shown that even relatively small-scale changes can have a large effect on ring/liner friction, in some cases reducing FMEP by as much as 30% from a smooth surface case. The measured FMEP reductions were in good agreement with the model predictions. The combined analysis of lubricant and surface design indicates that low-viscosity lubricants can be very effective in reducing friction, subject to component wear for extremely thin oils, which can be mitigated with further lubricant formulation and/or engineered surfaces. Hence a combined approach of lubricant design and appropriate wear reduction offers improved potential for minimum engine friction loss. Testing of low-friction lubricants showed that total engine FMEP reduced by up to {approx}16.5% from the commercial reference oil without significantly increasing oil consumption or blow-by flow. Piston friction studies indicate that a flatter piston with a more flexible skirt, together with optimizing the waviness and film thickness on the piston skirt offer significant friction reduction. Combined with low-friction ring-pack, material and lubricant parameters, a total power cylinder friction reduction of 30-50% is expected, translating to an engine efficiency increase of two percentage points from its current baseline towards the goal of 50% ARES engine efficiency. The design strategies developed in this study have promising potential for application in all modern reciprocating engines as they represent simple, low-cost methods to extract significant fuel savings. The current program has possible spinoffs and applications in other industries as well, including transportation, CHP, and diesel power generation. The progress made in this program has wide engine efficiency implications, and potential deployment of low-friction engine components or lubricants in the near term is quite possible.« less

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.

Ceramic technology for advanced heat engines project. Semiannual progress report, October 1985-March 1986

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

Not Available

1986-08-01

Significant accomplishments in fabricating cermaic components for the Department of Energy (DOE), National Aeronautics and Space Administration (NASA), and Department of Defense (DOD) advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, additional research is needed in materials and processing development, design methodology, and data base and life prediction. An assessment of needs was completed, and a five-year project plan was developed with extensive input from private industry. The objective of the project is to develop the industrial technology base required for reliable ceramics for application in advanced automotivemore » heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. although this is a generic materials project, the 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.« less

A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing

NASA Technical Reports Server (NTRS)

Grady, Joseph E.; Halbig, Michael C.; Singh, Mrityunjay

2015-01-01

In a NASA Aeronautics Research Institute (NARI) sponsored program entitled "A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing," evaluation of emerging materials and additive manufacturing technologies was carried out. These technologies may enable fully non-metallic gas turbine engines in the future. This paper highlights the results of engine system trade studies which were carried out to estimate reduction in engine emissions and fuel burn enabled due to advanced materials and manufacturing processes. A number of key engine components were identified in which advanced materials and additive manufacturing processes would provide the most significant benefits to engine operation. In addition, feasibility of using additive manufacturing technologies to fabricate gas turbine engine components from polymer and ceramic matrix composite were demonstrated. A wide variety of prototype components (inlet guide vanes (IGV), acoustic liners, engine access door, were additively manufactured using high temperature polymer materials. Ceramic matrix composite components included first stage nozzle segments and high pressure turbine nozzle segments for a cooled doublet vane. In addition, IGVs and acoustic liners were tested in simulated engine conditions in test rigs. The test results are reported and discussed in detail.

A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing

NASA Technical Reports Server (NTRS)

Grady, Joseph E.; Halbig, Michael C.; Singh, Mrityunjay

2015-01-01

In a NASA Aeronautics Research Institute (NARI) sponsored program entitled "A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing", evaluation of emerging materials and additive manufacturing technologies was carried out. These technologies may enable fully non-metallic gas turbine engines in the future. This paper highlights the results of engine system trade studies which were carried out to estimate reduction in engine emissions and fuel burn enabled due to advanced materials and manufacturing processes. A number of key engine components were identified in which advanced materials and additive manufacturing processes would provide the most significant benefits to engine operation. In addition, feasibility of using additive manufacturing technologies to fabricate gas turbine engine components from polymer and ceramic matrix composite were demonstrated. A wide variety of prototype components (inlet guide vanes (IGV), acoustic liners, engine access door) were additively manufactured using high temperature polymer materials. Ceramic matrix composite components included first stage nozzle segments and high pressure turbine nozzle segments for a cooled doublet vane. In addition, IGVs and acoustic liners were tested in simulated engine conditions in test rigs. The test results are reported and discussed in detail.

The Development of 2700-3000 F Environmental Barrier Coatings for SiC/SiC Ceramic Matrix Composites: Challenges and Opportunities

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2015-01-01

Environmental barrier coatings (EBCs) and SiCSiC ceramic matrix composites (CMCs) systems will play a crucial role in future turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is a key to enable the applications of the envisioned 2700-3000F EBC - CMC systems to help achieve next generation engine performance and durability goals. This paper will primarily address the performance requirements and design considerations of environmental barrier coatings for turbine engine applications. The emphasis is placed on current NASA candidate environmental barrier coating systems for SiCSiC CMCs, their performance benefits and design limitations in long-term operation and combustion environments. The efforts have been also directed to developing prime-reliant, self-healing 2700F EBC bond coat; and high stability, lower thermal conductivity, and durable EBC top coats. Major technical barriers in developing environmental barrier coating systems, the coating integrations with next generation CMCs having the improved environmental stability, cyclic durability, erosion-impact resistance, and long-term system performance will be described. The research and development opportunities for turbine engine environmental barrier coating systems by utilizing improved compositions, state-of-the-art processing methods, and simulated environment testing and durability modeling will be discussed.

Fibrin gels exhibit improved biological, structural, and mechanical properties compared with collagen gels in cell-based tendon tissue-engineered constructs.

PubMed

Breidenbach, Andrew P; Dyment, Nathaniel A; Lu, Yinhui; Rao, Marepalli; Shearn, Jason T; Rowe, David W; Kadler, Karl E; Butler, David L

2015-02-01

The prevalence of tendon and ligament injuries and inadequacies of current treatments is driving the need for alternative strategies such as tissue engineering. Fibrin and collagen biopolymers have been popular materials for creating tissue-engineered constructs (TECs), as they exhibit advantages of biocompatibility and flexibility in construct design. Unfortunately, a few studies have directly compared these materials for tendon and ligament applications. Therefore, this study aims at determining how collagen versus fibrin hydrogels affect the biological, structural, and mechanical properties of TECs during formation in vitro. Our findings show that tendon and ligament progenitor cells seeded in fibrin constructs exhibit improved tenogenic gene expression patterns compared with their collagen-based counterparts for approximately 14 days in culture. Fibrin-based constructs also exhibit improved cell-derived collagen alignment, increased linear modulus (2.2-fold greater) compared with collagen-based constructs. Cyclic tensile loading, which promotes the maturation of tendon constructs in a previous work, exhibits a material-dependent effect in this study. Fibrin constructs show trending reductions in mechanical, biological, and structural properties, whereas collagen constructs only show improved tenogenic expression in the presence of mechanical stimulation. These findings highlight that components of the mechanical stimulus (e.g., strain amplitude or time of initiation) need to be tailored to the material and cell type. Given the improvements in tenogenic expression, extracellular matrix organization, and material properties during static culture, in vitro findings presented here suggest that fibrin-based constructs may be a more suitable alternative to collagen-based constructs for tissue-engineered tendon/ligament repair.

Fibrin Gels Exhibit Improved Biological, Structural, and Mechanical Properties Compared with Collagen Gels in Cell-Based Tendon Tissue-Engineered Constructs

PubMed Central

Dyment, Nathaniel A.; Lu, Yinhui; Rao, Marepalli; Shearn, Jason T.; Rowe, David W.; Kadler, Karl E.; Butler, David L.

2015-01-01

The prevalence of tendon and ligament injuries and inadequacies of current treatments is driving the need for alternative strategies such as tissue engineering. Fibrin and collagen biopolymers have been popular materials for creating tissue-engineered constructs (TECs), as they exhibit advantages of biocompatibility and flexibility in construct design. Unfortunately, a few studies have directly compared these materials for tendon and ligament applications. Therefore, this study aims at determining how collagen versus fibrin hydrogels affect the biological, structural, and mechanical properties of TECs during formation in vitro. Our findings show that tendon and ligament progenitor cells seeded in fibrin constructs exhibit improved tenogenic gene expression patterns compared with their collagen-based counterparts for approximately 14 days in culture. Fibrin-based constructs also exhibit improved cell-derived collagen alignment, increased linear modulus (2.2-fold greater) compared with collagen-based constructs. Cyclic tensile loading, which promotes the maturation of tendon constructs in a previous work, exhibits a material-dependent effect in this study. Fibrin constructs show trending reductions in mechanical, biological, and structural properties, whereas collagen constructs only show improved tenogenic expression in the presence of mechanical stimulation. These findings highlight that components of the mechanical stimulus (e.g., strain amplitude or time of initiation) need to be tailored to the material and cell type. Given the improvements in tenogenic expression, extracellular matrix organization, and material properties during static culture, in vitro findings presented here suggest that fibrin-based constructs may be a more suitable alternative to collagen-based constructs for tissue-engineered tendon/ligament repair. PMID:25266738

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

Thermal barrier coatings issues in advanced land-based gas turbines

NASA Technical Reports Server (NTRS)

Parks, W. P.; Lee, W. Y.; Wright, I. G.

1995-01-01

The Department of Energy's Advanced Turbine System (ATS) program is aimed at forecasting the development of a new generation of land-based gas turbine systems with overall efficiencies significantly beyond those of current state-of-the-art machines, as well as greatly increased times between inspection and refurbishment, improved environmental impact, and decreased cost. The proposed duty cycle of ATS turbines will require the use of different criteria in the design of the materials for the critical hot gas path components. In particular, thermal barrier coatings will be an essential feature of the hot gas path components in these machines. While such coatings are routinely used in high-performance aircraft engines and are becoming established in land-based turbines, the requirements of the ATS turbine application are sufficiently different that significant improvements in thermal barrier coating technology will be necessary. In particular, it appears that thermal barrier coatings will have to function on all airfoil sections of the first stage vanes and blades to provide the significant temperature reduction required. In contrast, such coatings applied to the blades and vances of advanced aircraft engines are intended primarily to reduce air cooling requirements and extend component lifetime; failure of those coatings can be tolerated without jeopardizing mechanical or corrosion performance. A major difference is that in ATS turbines these components will be totally reliant on thermal barrier coatings which will, therefore, need to be highly reliable even over the leading edges of first stage blades. Obviously, the ATS program provides a very challenging opportunity for TBC's, and involves some significant opportunities to extend this technology.

A Prototype for the Support of Integrated Software Process Development and Improvement

NASA Astrophysics Data System (ADS)

Porrawatpreyakorn, Nalinpat; Quirchmayr, Gerald; Chutimaskul, Wichian

An efficient software development process is one of key success factors for quality software. Not only can the appropriate establishment but also the continuous improvement of integrated project management and of the software development process result in efficiency. This paper hence proposes a software process maintenance framework which consists of two core components: an integrated PMBOK-Scrum model describing how to establish a comprehensive set of project management and software engineering processes and a software development maturity model advocating software process improvement. Besides, a prototype tool to support the framework is introduced.

Facet‐Engineered Surface and Interface Design of Photocatalytic Materials

PubMed Central

Wang, Lili; Li, Zhengquan

2016-01-01

The facet‐engineered surface and interface design for photocatalytic materials has been proven as a versatile approach to enhance their photocatalytic performance. This review article encompasses some recent advances in the facet engineering that has been performed to control the surface of mono‐component semiconductor systems and to design the surface and interface structures of multi‐component heterostructures toward photocatalytic applications. The review begins with some key points which should receive attention in the facet engineering on photocatalytic materials. We then discuss the synthetic approaches to achieve the facet control associated with the surface and interface design. In the following section, the facet‐engineered surface design on mono‐component photocatalytic materials is introduced, which forms a basis for the discussion on more complex systems. Subsequently, we elucidate the facet‐engineered surface and interface design of multi‐component photocatalytic materials. Finally, the existing challenges and future prospects are discussed. PMID:28105398

Enhancements to the Engine Data Interpretation System (EDIS)

NASA Technical Reports Server (NTRS)

Hofmann, Martin O.

1993-01-01

The Engine Data Interpretation System (EDIS) expert system project assists the data review personnel at NASA/MSFC in performing post-test data analysis and engine diagnosis of the Space Shuttle Main Engine (SSME). EDIS uses knowledge of the engine, its components, and simple thermodynamic principles instead of, and in addition to, heuristic rules gathered from the engine experts. EDIS reasons in cooperation with human experts, following roughly the pattern of logic exhibited by human experts. EDIS concentrates on steady-state static faults, such as small leaks, and component degradations, such as pump efficiencies. The objective of this contract was to complete the set of engine component models, integrate heuristic rules into EDIS, integrate the Power Balance Model into EDIS, and investigate modification of the qualitative reasoning mechanisms to allow 'fuzzy' value classification. The results of this contract is an operational version of EDIS. EDIS will become a module of the Post-Test Diagnostic System (PTDS) and will, in this context, provide system-level diagnostic capabilities which integrate component-specific findings provided by other modules.

Towards an Automated Full-Turbofan Engine Numerical Simulation

NASA Technical Reports Server (NTRS)

Reed, John A.; Turner, Mark G.; Norris, Andrew; Veres, Joseph P.

2003-01-01

The objective of this study was to demonstrate the high-fidelity numerical simulation of a modern high-bypass turbofan engine. The simulation utilizes the Numerical Propulsion System Simulation (NPSS) thermodynamic cycle modeling system coupled to a high-fidelity full-engine model represented by a set of coupled three-dimensional computational fluid dynamic (CFD) component models. Boundary conditions from the balanced, steady-state cycle model are used to define component boundary conditions in the full-engine model. Operating characteristics of the three-dimensional component models are integrated into the cycle model via partial performance maps generated automatically from the CFD flow solutions using one-dimensional meanline turbomachinery programs. This paper reports on the progress made towards the full-engine simulation of the GE90-94B engine, highlighting the generation of the high-pressure compressor partial performance map. The ongoing work will provide a system to evaluate the steady and unsteady aerodynamic and mechanical interactions between engine components at design and off-design operating conditions.

Enhancements to the Engine Data Interpretation System (EDIS)

NASA Technical Reports Server (NTRS)

Hofmann, Martin O.

1993-01-01

The Engine Data Interpretation System (EDIS) expert system project assists the data review personnel at NASA/MSFC in performing post-test data analysis and engine diagnosis of the Space Shuttle Main Engine (SSME). EDIS uses knowledge of the engine, its components, and simple thermodynamic principles instead of, and in addition to, heuristic rules gathered from the engine experts. EDIS reasons in cooperation with human experts, following roughly the pattern of logic exhibited by human experts. EDIS concentrates on steady-state static faults, such as small leaks, and component degradations, such as pump efficiencies. The objective of this contract was to complete the set of engine component models, integrate heuristic rules into EDIS, integrate the Power Balance Model into EDIS, and investigate modification of the qualitative reasoning mechanisms to allow 'fuzzy' value classification. The result of this contract is an operational version of EDIS. EDIS will become a module of the Post-Test Diagnostic System (PTDS) and will, in this context, provide system-level diagnostic capabilities which integrate component-specific findings provided by other modules.

Agile Development of Various Computational Power Adaptive Web-Based Mobile-Learning Software Using Mobile Cloud Computing

ERIC Educational Resources Information Center

Zadahmad, Manouchehr; Yousefzadehfard, Parisa

2016-01-01

Mobile Cloud Computing (MCC) aims to improve all mobile applications such as m-learning systems. This study presents an innovative method to use web technology and software engineering's best practices to provide m-learning functionalities hosted in a MCC-learning system as service. Components hosted by MCC are used to empower developers to create…

Energy efficient engine component development and integration program

NASA Technical Reports Server (NTRS)

1981-01-01

The technology that will improve the energy efficiency of propulsion systems for subsonic commercial aircraft is investigated. A reduction of 14.4% in cruise installed sfc (0.572 versus 0.668 for the CF6-50C) and a direct operation cost reduction in excess of the 5% goal is projected. Noise and emissions projections are consistent with the established goals.

Computational Flow Analysis of a Left Ventricular Assist Device

NASA Technical Reports Server (NTRS)

Kiris, Cetin; Kwak, Dochan; Benkowski, Robert

1995-01-01

Computational fluid dynamics has been developed to a level where it has become an Indispensable part of aerospace research and design. Technology developed foe aerospace applications am also be utilized for the benefit of human health. For example, a flange-to-flange rocket engine fuel-pump simulation includes the rotating and non-rotating components: the flow straighteners, the impeller, and diffusers A Ventricular Assist Device developed by NASA Johnson Space Center and Baylor College of Medicine has a design similar to a rocket engine fuel pump in that it also consists of a flow straightener, an impeller, and a diffuser. Accurate and detailed knowledge of the flowfield obtained by incompressible flow calculations can be greatly beneficial to designers in their effort to reduce the cost and improve the reliability of these devices. In addition to the geometric complexities, a variety of flow phenomena are encountered in biofluids Then include turbulent boundary layer separation, wakes, transition, tip vortex resolution, three-dimensional effects, and Reynolds number effects. In order to increase the role of Computational Fluid Dynamics (CFD) in the design process the CFD analysis tools must be evaluated and validated so that designers gain Confidence in their use. The incompressible flow solver, INS3D, has been applied to flow inside of a liquid rocket engine turbopump components and extensively validated. This paper details how the computational flow simulation capability developed for liquid rocket engine pump component analysis has bean applied to the Left Ventricular Assist Device being developed jointly by NASA JSC and Baylor College of Medicine.

Molecular response of canola to salt stress: insights on tolerance mechanisms.

PubMed

Shokri-Gharelo, Reza; Noparvar, Pouya Motie

2018-01-01

Canola ( Brassica napus L. ) is widely cultivated around the world for the production of edible oils and biodiesel fuel. Despite many canola varieties being described as 'salt-tolerant', plant yield and growth decline drastically with increasing salinity. Although many studies have resulted in better understanding of the many important salt-response mechanisms that control salt signaling in plants, detoxification of ions, and synthesis of protective metabolites, the engineering of salt-tolerant crops has only progressed slowly. Genetic engineering has been considered as an efficient method for improving the salt tolerance of canola but there are many unknown or little-known aspects regarding canola response to salinity stress at the cellular and molecular level. In order to develop highly salt-tolerant canola, it is essential to improve knowledge of the salt-tolerance mechanisms, especially the key components of the plant salt-response network. In this review, we focus on studies of the molecular response of canola to salinity to unravel the different pieces of the salt response puzzle. The paper includes a comprehensive review of the latest studies, particularly of proteomic and transcriptomic analysis, including the most recently identified canola tolerance components under salt stress, and suggests what researchers should focus on in future studies.

Predictable Particle Engineering: Programming the Energy Level, Carrier Generation, and Conductivity of Core-Shell Particles.

PubMed

Yuan, Conghui; Wu, Tong; Mao, Jie; Chen, Ting; Li, Yuntong; Li, Min; Xu, Yiting; Zeng, Birong; Luo, Weiang; Yu, Lingke; Zheng, Gaofeng; Dai, Lizong

2018-06-20

Core-shell structures are of particular interest in the development of advanced composite materials as they can efficiently bring different components together at nanoscale. The advantage of this structure greatly relies on the crucial design of both core and shell, thus achieving an intercomponent synergistic effect. In this report, we show that decorating semiconductor nanocrystals with a boronate polymer shell can easily achieve programmable core-shell interactions. Taking ZnO and anatase TiO 2 nanocrystals as inner core examples, the effective core-shell interactions can narrow the band gap of semiconductor nanocrystals, change the HOMO and LUMO levels of boronate polymer shell, and significantly improve the carrier density of core-shell particles. The hole mobility of core-shell particles can be improved by almost 9 orders of magnitude in comparison with net boronate polymer, while the conductivity of core-shell particles is at most 30-fold of nanocrystals. The particle engineering strategy is based on two driving forces: catechol-surface binding and B-N dative bonding and having a high ability to control and predict the shell thickness. Also, this approach is applicable to various inorganic nanoparticles with different components, sizes, and shapes.

Genetic transformation of fruit trees: current status and remaining challenges.

PubMed

Gambino, Giorgio; Gribaudo, Ivana

2012-12-01

Genetic transformation has emerged as a powerful tool for genetic improvement of fruit trees hindered by their reproductive biology and their high levels of heterozygosity. For years, genetic engineering of fruit trees has focussed principally on enhancing disease resistance (against viruses, fungi, and bacteria), although there are few examples of field cultivation and commercial application of these transgenic plants. In addition, over the years much work has been performed to enhance abiotic stress tolerance, to induce modifications of plant growth and habit, to produce marker-free transgenic plants and to improve fruit quality by modification of genes that are crucially important in the production of specific plant components. Recently, with the release of several genome sequences, studies of functional genomics are becoming increasingly important: by modification (overexpression or silencing) of genes involved in the production of specific plant components is possible to uncover regulatory mechanisms associated with the biosynthesis and catabolism of metabolites in plants. This review focuses on the main advances, in recent years, in genetic transformation of the most important species of fruit trees, devoting particular attention to functional genomics approaches and possible future challenges of genetic engineering for these species in the post-genomic era.

High variable mixture ratio oxygen/hydrogen engine

NASA Technical Reports Server (NTRS)

Erickson, C. M.; Tu, W. H.; Weiss, A. H.

1988-01-01

The ability of an O2/H2 engine to operate over a range of high-propellant mixture ratios was previously shown to be advantageous in single stage to orbit (SSTO) vehicles. The results are presented for the analysis of high-performance engine power cycles operating over propellant mixture ratio ranges of 12 to 6 and 9 to 6. A requirement to throttle up to 60 percent of nominal thrust was superimposed as a typical throttle range to limit vehicle acceleration as propellant is expended. The object of the analysis was to determine areas of concern relative to component and engine operability or potential hazards resulting from the operating requirements and ranges of conditions that derive from the overall engine requirements. The SSTO mission necessitates a high-performance, lightweight engine. Therefore, staged combustion power cycles employing either dual fuel-rich preburners or dual mixed (fuel-rich and oxygen-rich) preburners were examined. Engine mass flow and power balances were made and major component operating ranges were defined. Component size and arrangement were determined through engine layouts for one of the configurations evaluated. Each component is being examined to determine if there are areas of concern with respect to component efficiency, operability, reliability, or hazard. The effects of reducing the maximum chamber pressure were investigated for one of the cycles.

Blade loss transient dynamics analysis, volume 2. Task 2: Theoretical and analytical development. Task 3: Experimental verification

NASA Technical Reports Server (NTRS)

Gallardo, V. C.; Storace, A. S.; Gaffney, E. F.; Bach, L. J.; Stallone, M. J.

1981-01-01

The component element method was used to develop a transient dynamic analysis computer program which is essentially based on modal synthesis combined with a central, finite difference, numerical integration scheme. The methodology leads to a modular or building-block technique that is amenable to computer programming. To verify the analytical method, turbine engine transient response analysis (TETRA), was applied to two blade-out test vehicles that had been previously instrumented and tested. Comparison of the time dependent test data with those predicted by TETRA led to recommendations for refinement or extension of the analytical method to improve its accuracy and overcome its shortcomings. The development of working equations, their discretization, numerical solution scheme, the modular concept of engine modelling, the program logical structure and some illustrated results are discussed. The blade-loss test vehicles (rig full engine), the type of measured data, and the engine structural model are described.

Development of a Temperature Sensor for Jet Engine and Space Mission Applications

NASA Technical Reports Server (NTRS)

Patterson, Richard L.; Hammoud, Ahmad; Elbuluk, Malik; Culley, Dennis

2008-01-01

Electronics for Distributed Turbine Engine Control and Space Exploration Missions are expected to encounter extreme temperatures and wide thermal swings. In particular, circuits deployed in a jet engine compartment are likely to be exposed to temperatures well exceeding 150 C. To meet this requirement, efforts exist at the NASA Glenn Research Center (GRC), in support of the Fundamental Aeronautics Program/Subsonic Fixed Wing Project, to develop temperature sensors geared for use in high temperature environments. The sensor and associated circuitry need to be located in the engine compartment under distributed control architecture to simplify system design, improve reliability, and ease signal multiplexing. Several circuits were designed using commercial-off-the-shelf as well as newly-developed components to perform temperature sensing at high temperatures. The temperature-sensing circuits will be described along with the results pertaining to their performance under extreme temperature.

Engineered nanomaterials for solar energy conversion.

PubMed

Mlinar, Vladan

2013-02-01

Understanding how to engineer nanomaterials for targeted solar-cell applications is the key to improving their efficiency and could lead to breakthroughs in their design. Proposed mechanisms for the conversion of solar energy to electricity are those exploiting the particle nature of light in conventional photovoltaic cells, and those using the collective electromagnetic nature, where light is captured by antennas and rectified. In both cases, engineered nanomaterials form the crucial components. Examples include arrays of semiconductor nanostructures as an intermediate band (so called intermediate band solar cells), semiconductor nanocrystals for multiple exciton generation, or, in antenna-rectifier cells, nanomaterials for effective optical frequency rectification. Here, we discuss the state of the art in p-n junction, intermediate band, multiple exciton generation, and antenna-rectifier solar cells. We provide a summary of how engineered nanomaterials have been used in these systems and a discussion of the open questions.

Medical imaging education in biomedical engineering curriculum: courseware development and application through a hybrid teaching model.

PubMed

Zhao, Weizhao; Li, Xiping; Chen, Hairong; Manns, Fabrice

2012-01-01

Medical Imaging is a key training component in Biomedical Engineering programs. Medical imaging education is interdisciplinary training, involving physics, mathematics, chemistry, electrical engineering, computer engineering, and applications in biology and medicine. Seeking an efficient teaching method for instructors and an effective learning environment for students has long been a goal for medical imaging education. By the support of NSF grants, we developed the medical imaging teaching software (MITS) and associated dynamic assessment tracking system (DATS). The MITS/DATS system has been applied to junior and senior medical imaging classes through a hybrid teaching model. The results show that student's learning gain improved, particularly in concept understanding and simulation project completion. The results also indicate disparities in subjective perception between junior and senior classes. Three institutions are collaborating to expand the courseware system and plan to apply it to different class settings.

Using Innovative Technologies for Manufacturing and Evaluating Rocket Engine Hardware

NASA Technical Reports Server (NTRS)

Betts, Erin M.; Hardin, Andy

2011-01-01

Many of the manufacturing and evaluation techniques that are currently used for rocket engine component production are traditional methods that have been proven through years of experience and historical precedence. As we enter into a new space age where new launch vehicles are being designed and propulsion systems are being improved upon, it is sometimes necessary to adopt new and innovative techniques for manufacturing and evaluating hardware. With a heavy emphasis on cost reduction and improvements in manufacturing time, manufacturing techniques such as Direct Metal Laser Sintering (DMLS) and white light scanning are being adopted and evaluated for their use on J-2X, with hopes of employing both technologies on a wide variety of future projects. DMLS has the potential to significantly reduce the processing time and cost of engine hardware, while achieving desirable material properties by using a layered powdered metal manufacturing process in order to produce complex part geometries. The white light technique is a non-invasive method that can be used to inspect for geometric feature alignment. Both the DMLS manufacturing method and the white light scanning technique have proven to be viable options for manufacturing and evaluating rocket engine hardware, and further development and use of these techniques is recommended.

Microstructure Evolution and Durability of Advanced Environmental Barrier Coating Systems for SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Evans, Laura J.; McCue, Terry R.; Harder, Bryan

2016-01-01

Environmental barrier coated SiC-SiC 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. Advanced HfO2 and rare earth silicate environmental barrier coatings (EBCs), along with multicomponent hafnium and rare earth silicide EBC bond coats have been developed. The coating degradation mechanisms in the laboratory simulated engine thermal cycling, and fatigue-creep operating environments are also being investigated. This paper will focus on the microstructural and compositional evolutions of an advanced environmental barrier coating system on a SiC-SiC CMC substrate during the high temperature simulated durability tests, by using a Field Emission Gun Scanning Electron Microscopy, Energy Dispersive Spectroscopy (EDS) and Wavelength Dispersive Spectroscopy (WDS). The effects of Calcium-Magnesium-Alumino-Silicate (CMAS) from road sand or volcano-ash deposits on the degradation mechanisms of the environmental barrier coating systems will also be discussed. The detailed analysis results help understand the EBC-CMC system performance, aiming at the durability improvements to achieve more robust, prime-reliant environmental barrier coatings.

CMC Property Variability and Life Prediction Methods for Turbine Engine Component Application

NASA Technical Reports Server (NTRS)

Cheplak, Matthew L.

2004-01-01

The ever increasing need for lower density and higher temperature-capable materials for aircraft engines has led to the development of Ceramic Matrix Composites (CMCs). Today's aircraft engines operate with >3000"F gas temperatures at the entrance to the turbine section, but unless heavily cooled, metallic components cannot operate above approx.2000 F. CMCs attempt to push component capability to nearly 2700 F with much less cooling, which can help improve engine efficiency and performance in terms of better fuel efficiency, higher thrust, and reduced emissions. The NASA Glenn Research Center has been researching the benefits of the SiC/SiC CMC for engine applications. A CMC is made up of a matrix material, fibers, and an interphase, which is a protective coating over the fibers. There are several methods or architectures in which the orientation of the fibers can be manipulated to achieve a particular material property objective as well as a particular component geometric shape and size. The required shape manipulation can be a limiting factor in the design and performance of the component if there is a lack of bending capability of the fiber as making the fiber more flexible typically sacrifices strength and other fiber properties. Various analysis codes are available (pcGINA, CEMCAN) that can predict the effective Young's Moduli, thermal conductivities, coefficients of thermal expansion (CTE), and various other properties of a CMC. There are also various analysis codes (NASAlife) that can be used to predict the life of CMCs under expected engine service conditions. The objective of this summer study is to utilize and optimize these codes for examining the tradeoffs between CMC properties and the complex fiber architectures that will be needed for several different component designs. For example, for the pcGINA code, there are six variations of architecture available. Depending on which architecture is analyzed, the user is able to specify the fiber tow size, tow spacing, weave parameter, and angle of orientation of fibers. By holding the volume fraction of the fibers constant, variations in tow spacing can be explored for different architectures. The CMC material properties are usually calculated assuming the component is manufactured perfectly. However, this is typically not the case so that a quantification of the material property variability is needed to account for processing and/or manufacturing imperfections. The overall inputs and outputs are presented using a regression software to rapidly investigate the tradeoffs associated with fiber architecture, material properties, and ultimately cost. This information is then propagated through lifing models and Larson-Miller data to assess timehemperature-dependent CMC strength. In addition, a first order cost estimation will be quantified from a current qualitative perspective. This cost estimation includes the manufacturing challenges, such as tooling, as well as the component cost for a particular application. Ultimately, a cost to performance ratio should be established that compares the effectiveness of CMCs to their current rival, nickel superalloys.

High-Performance SiC/SiC Ceramic Composite Systems Developed for 1315 C (2400 F) Engine Components

NASA Technical Reports Server (NTRS)

DiCarlo, James A.; Yun, Hee Mann; Morscher, Gregory N.; Bhatt, Ramakrishna T.

2004-01-01

As structural materials for hot-section components in advanced aerospace and land-based gas turbine engines, silicon carbide (SiC) ceramic matrix composites reinforced by high performance SiC fibers offer a variety of performance advantages over current bill-of-materials, such as nickel-based superalloys. These advantages are based on the SiC/SiC composites displaying higher temperature capability for a given structural load, lower density (approximately 30- to 50-percent metal density), and lower thermal expansion. These properties should, in turn, result in many important engine benefits, such as reduced component cooling air requirements, simpler component design, reduced support structure weight, improved fuel efficiency, reduced emissions, higher blade frequencies, reduced blade clearances, and higher thrust. Under the NASA Ultra-Efficient Engine Technology (UEET) Project, much progress has been made at the NASA Glenn Research Center in identifying and optimizing two highperformance SiC/SiC composite systems. The table compares typical properties of oxide/oxide panels and SiC/SiC panels formed by the random stacking of balanced 0 degrees/90 degrees fabric pieces reinforced by the indicated fiber types. The Glenn SiC/SiC systems A and B (shaded area of the table) were reinforced by the Sylramic-iBN SiC fiber, which was produced at Glenn by thermal treatment of the commercial Sylramic SiC fiber (Dow Corning, Midland, MI; ref. 2). The treatment process (1) removes boron from the Sylramic fiber, thereby improving fiber creep, rupture, and oxidation resistance and (2) allows the boron to react with nitrogen to form a thin in situ grown BN coating on the fiber surface, thereby providing an oxidation-resistant buffer layer between contacting fibers in the fabric and the final composite. The fabric stacks for all SiC/SiC panels were provided to GE Power Systems Composites for chemical vapor infiltration of Glenn designed BN fiber coatings and conventional SiC matrices. Composite panels with system B were heat treated at Glenn, and the pores that remained open were filled by silicon melt infiltration (MI). Panels with system A and the other SiC/SiC systems were not heat treated, and remaining open pores in these systems were filled with SiC slurry and silicon MI.

Component-specific modeling

NASA Technical Reports Server (NTRS)

Mcknight, R. L.

1985-01-01

Accomplishments are described for the second year effort of a 3-year program to develop methodology for component specific modeling of aircraft engine hot section components (turbine blades, turbine vanes, and burner liners). These accomplishments include: (1) engine thermodynamic and mission models; (2) geometry model generators; (3) remeshing; (4) specialty 3-D inelastic stuctural analysis; (5) computationally efficient solvers, (6) adaptive solution strategies; (7) engine performance parameters/component response variables decomposition and synthesis; (8) integrated software architecture and development, and (9) validation cases for software developed.

Integrated two-cylinder liquid piston Stirling engine

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

Yang, Ning; Rickard, Robert; Pluckter, Kevin

2014-10-06

Heat engines utilizing the Stirling cycle may run on low temperature differentials with the capacity to function at high efficiency due to their near-reversible operation. However, current approaches to building Stirling engines are laborious and costly. Typically the components are assembled by hand and additional components require a corresponding increase in manufacturing complexity, akin to electronics before the integrated circuit. We present a simple and integrated approach to fabricating Stirling engines with precisely designed cylinders. We utilize computer aided design and one-step, planar machining to form all components of the engine. The engine utilizes liquid pistons and displacers to harnessmore » useful work from heat absorption and rejection. As a proof of principle of the integrated design, a two-cylinder engine is produced and characterized and liquid pumping is demonstrated.« less

MC-1 Engine Valves, Lessons Learned

NASA Technical Reports Server (NTRS)

Laszar, John

2003-01-01

Many lessons were learned during the development of the valves for the MC-1 engine. The purpose of this report is to focus on a variety of issues related to the engine valves and convey the lessons learned. This paper will not delve into detailed technical analysis of the components. None of the lessons learned are new or surprising, but simply reinforce the importance of addressing the details of the design early, at the component level. The Marshall Space Flight Center (MSFC), Huntsville, Alabama developed the MC-1 engine, a LOX / FW-1, 60,000 pound thrust engine. This engine was developed under the Low Cost Boost Technology office at MSFC and proved to be a very successful project for the MSFC Propulsion team and the various subcontractors working the development of the engine and its components.

Integrated two-cylinder liquid piston Stirling engine

NASA Astrophysics Data System (ADS)

Yang, Ning; Rickard, Robert; Pluckter, Kevin; Sulchek, Todd

2014-10-01

Heat engines utilizing the Stirling cycle may run on low temperature differentials with the capacity to function at high efficiency due to their near-reversible operation. However, current approaches to building Stirling engines are laborious and costly. Typically the components are assembled by hand and additional components require a corresponding increase in manufacturing complexity, akin to electronics before the integrated circuit. We present a simple and integrated approach to fabricating Stirling engines with precisely designed cylinders. We utilize computer aided design and one-step, planar machining to form all components of the engine. The engine utilizes liquid pistons and displacers to harness useful work from heat absorption and rejection. As a proof of principle of the integrated design, a two-cylinder engine is produced and characterized and liquid pumping is demonstrated.

Dual-fuel, dual-mode rocket engine

NASA Technical Reports Server (NTRS)

Martin, James A. (Inventor)

1989-01-01

The invention relates to a dual fuel, dual mode rocket engine designed to improve the performance of earth-to-orbit vehicles. For any vehicle that operates from the earth's surface to earth orbit, it is advantageous to use two different fuels during its ascent. A high density impulse fuel, such as kerosene, is most efficient during the first half of the trajectory. A high specific impulse fuel, such as hydrogen, is most efficient during the second half of the trajectory. The invention allows both fuels to be used with a single rocket engine. It does so by adding a minimum number of state-of-the-art components to baseline single made rocket engines, and is therefore relatively easy to develop for near term applications. The novelty of this invention resides in the mixing of fuels before exhaust nozzle cooling. This allows all of the engine fuel to cool the exhaust nozzle, and allows the ratio of fuels used throughout the flight depend solely on performance requirements, not cooling requirements.

Synthetic Vortex Generator Jets Used to Control Separation on Low-Pressure Turbine Airfoils

NASA Technical Reports Server (NTRS)

Ashpis, David E.; Volino, Ralph J.

2005-01-01

Low-pressure turbine (LPT) airfoils are subject to increasingly stronger pressure gradients as designers impose higher loading in an effort to improve efficiency and lower cost by reducing the number of airfoils in an engine. When the adverse pressure gradient on the suction side of these airfoils becomes strong enough, the boundary layer will separate. Separation bubbles, particularly those that fail to reattach, can result in a significant loss of lift and a subsequent degradation of engine efficiency. The problem is particularly relevant in aircraft engines. Airfoils optimized to produce maximum power under takeoff conditions may still experience boundary layer separation at cruise conditions because of the thinner air and lower Reynolds numbers at altitude. Component efficiency can drop significantly between takeoff and cruise conditions. The decrease is about 2 percent in large commercial transport engines, and it could be as large as 7 percent in smaller engines operating at higher altitudes. Therefore, it is very beneficial to eliminate, or at least reduce, the separation bubble.

RESEARCH AND DESIGN ABOUT VERSATILE 3D-CAD ENGINE FOR CONSTRUCTION

NASA Astrophysics Data System (ADS)

Tanaka, Shigenori; Kubota, Satoshi; Kitagawa, Etsuji; Monobe, Kantaro; Nakamura, Kenji

In the construction field of Japan, it is an important subject to build the environment where 3D-CAD data is used for CALS/EC, information construction, and an improvement in productivity. However, in the construction field, 3D-CAD software does not exist under the present circumstances. Then, in order to support development of domestic 3D-CAD software, it is required to develop a 3D-CAD engine. In this research, in order to familiarize the 3D-CAD software at low cost and quickly and build the environment where the 3D-CAD software is utilizable, investigation for designing a 3D-CAD engine is proposed. The target for investigation are the use scene of 3D-CAD, the seeds which accompany 3D-CAD, a standardization trend, existing products, IT component engineering. Based on results of the investigation, the functional requirements for the 3D-CAD engine for the construction field were concluded.

Transporter engineering in biomass utilization by yeast.

PubMed

Hara, Kiyotaka Y; Kobayashi, Jyumpei; Yamada, Ryosuke; Sasaki, Daisuke; Kuriya, Yuki; Hirono-Hara, Yoko; Ishii, Jun; Araki, Michihiro; Kondo, Akihiko

2017-11-01

Biomass resources are attractive carbon sources for bioproduction because of their sustainability. Many studies have been performed using biomass resources to produce sugars as carbon sources for cell factories. Expression of biomass hydrolyzing enzymes in cell factories is an important approach for constructing biomass-utilizing bioprocesses because external addition of these enzymes is expensive. In particular, yeasts have been extensively engineered to be cell factories that directly utilize biomass because of their manageable responses to many genetic engineering tools, such as gene expression, deletion and editing. Biomass utilizing bioprocesses have also been developed using these genetic engineering tools to construct metabolic pathways. However, sugar input and product output from these cells are critical factors for improving bioproduction along with biomass utilization and metabolic pathways. Transporters are key components for efficient input and output activities. In this review, we focus on transporter engineering in yeast to enhance bioproduction from biomass resources. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Plant cell wall engineering: applications in biofuel production and improved human health.

PubMed

Burton, Rachel A; Fincher, Geoffrey B

2014-04-01

Plant cell walls consist largely of cellulose, non-cellulosic polysaccharides and lignin. Concerted attempts are underway to convert wall polysaccharides from crop plant residues into renewable transport fuels and other valuable products, and to exploit the dietary benefits of cereal grain wall polysaccharides in human health. Attempts to improve plant performance for these applications have involved the manipulation of the levels and structures of wall components. Some successes in altering non-cellulosic polysaccharides has been achieved, but it would appear that drastic changes in cellulose are more difficult to engineer. Nevertheless, future prospects for both genetically modified (GM) and non-GM technologies to modify plant cell wall composition and structure remain bright, and will undoubtedly find applications beyond the current focus on human health and biofuel production. Copyright © 2013. Published by Elsevier Ltd.

Capacity enhancement of indigenous expansion engine based helium liquefier

NASA Astrophysics Data System (ADS)

Doohan, R. S.; Kush, P. K.; Maheshwari, G.

2017-02-01

Development of technology and understanding for large capacity helium refrigeration and liquefaction at helium temperature is indispensable for coming-up projects. A new version of helium liquefier designed and built to provide approximately 35 liters of liquid helium per hour. The refrigeration capacity of this reciprocating type expansion engine machine has been increased from its predecessor version with continuous improvement and deficiency debugging. The helium liquefier has been built using components by local industries including cryogenic Aluminum plate fin heat exchangers. Two compressors with nearly identical capacity have been deployed for the operation of system. Together they consume about 110 kW of electric power. The system employs liquid Nitrogen precooling to enhance liquid Helium yield. This paper describes details of the cryogenic expander design improvements, reconfiguration of heat exchangers, performance simulation and their experimental validation.

Reliability and Productivity Modeling for the Optimization of Separated Spacecraft Interferometers

NASA Technical Reports Server (NTRS)

Kenny, Sean (Technical Monitor); Wertz, Julie

2002-01-01

As technological systems grow in capability, they also grow in complexity. Due to this complexity, it is no longer possible for a designer to use engineering judgement to identify the components that have the largest impact on system life cycle metrics, such as reliability, productivity, cost, and cost effectiveness. One way of identifying these key components is to build quantitative models and analysis tools that can be used to aid the designer in making high level architecture decisions. Once these key components have been identified, two main approaches to improving a system using these components exist: add redundancy or improve the reliability of the component. In reality, the most effective approach to almost any system will be some combination of these two approaches, in varying orders of magnitude for each component. Therefore, this research tries to answer the question of how to divide funds, between adding redundancy and improving the reliability of components, to most cost effectively improve the life cycle metrics of a system. While this question is relevant to any complex system, this research focuses on one type of system in particular: Separate Spacecraft Interferometers (SSI). Quantitative models are developed to analyze the key life cycle metrics of different SSI system architectures. Next, tools are developed to compare a given set of architectures in terms of total performance, by coupling different life cycle metrics together into one performance metric. Optimization tools, such as simulated annealing and genetic algorithms, are then used to search the entire design space to find the "optimal" architecture design. Sensitivity analysis tools have been developed to determine how sensitive the results of these analyses are to uncertain user defined parameters. Finally, several possibilities for the future work that could be done in this area of research are presented.

Systems Level Engineering of Plant Cell Wall Biosynthesis to Improve Biofuel Feedstock Quality

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

Hazen, Samuel

2013-09-27

Our new regulatory model of cell wall biosynthesis proposes original network architecture with several newly incorporated components. The mapped set of protein-DNA interactions will serve as a foundation for 1) understanding the regulation of a complex and integral plant component and 2) the manipulation of crop species for biofuel and biotechnology purposes. This study revealed interesting and novel aspects of grass growth and development and further enforce the importance of a grass model system. By functionally characterizing a suite of genes, we have begun to improve the sparse model for transcription regulation of biomass accumulation in grasses. In the process,more » we have advanced methodology and brachy molecular genetic tools that will serve as valuable community resource.« less

Melt-infiltrated Sic Composites for Gas Turbine Engine Applications

NASA Technical Reports Server (NTRS)

Morscher, Gregory N.; Pujar, Vijay V.

2004-01-01

SiC-SiC ceramic matrix composites (CMCs) manufactured by the slurry -cast melt-infiltration (MI) process are leading candidates for many hot-section turbine engine components. A collaborative program between Goodrich Corporation and NASA-Glenn Research Center is aimed at determining and optimizing woven SiC/SiC CMC performance and reliability. A variety of composites with different fiber types, interphases and matrix compositions have been fabricated and evaluated. Particular focus of this program is on the development of interphase systems that will result in improved intermediate temperature stressed-oxidation properties of this composite system. The effect of the different composite variations on composite properties is discussed and, where appropriate, comparisons made to properties that have been generated under NASA's Ultra Efficient Engine Technology (UEET) Program.

Knowledge Engineering Aspects of Affective Bi-Modal Educational Applications

NASA Astrophysics Data System (ADS)

Alepis, Efthymios; Virvou, Maria; Kabassi, Katerina

This paper analyses the knowledge and software engineering aspects of educational applications that provide affective bi-modal human-computer interaction. For this purpose, a system that provides affective interaction based on evidence from two different modes has been developed. More specifically, the system's inferences about students' emotions are based on user input evidence from the keyboard and the microphone. Evidence from these two modes is combined by a user modelling component that incorporates user stereotypes as well as a multi criteria decision making theory. The mechanism that integrates the inferences from the two modes has been based on the results of two empirical studies that were conducted in the context of knowledge engineering of the system. The evaluation of the developed system showed significant improvements in the recognition of the emotional states of users.

Acoustic Performance of Drive Rig Mufflers for Model Scale Engine Testing

NASA Technical Reports Server (NTRS)

Stephens, David, B.

2013-01-01

Aircraft engine component testing at the NASA Glenn Research Center (GRC) includes acoustic testing of scale model fans and propellers in the 9- by15-Foot Low Speed Wind Tunnel (LSWT). This testing utilizes air driven turbines to deliver power to the article being studied. These air turbines exhaust directly downstream of the model in the wind tunnel test section and have been found to produce significant unwanted noise that reduces the quality of the acoustic measurements of the engine model being tested. This report describes an acoustic test of a muffler designed to mitigate the extraneous turbine noise. The muffler was found to provide acoustic attenuation of at least 8 dB between 700 Hz and 20 kHz which significantly improves the quality of acoustic measurements in the facility.

Handbook of data on selected engine components for solar thermal applications

NASA Technical Reports Server (NTRS)

1979-01-01

A data base on developed and commercially available power conversion system components for Rankine and Brayton cycle engines, which have potential application to solar thermal power-generating systems is presented. The status of the Stirling engine is discussed.

Making Ceramic Components For Advanced Aircraft Engines

NASA Technical Reports Server (NTRS)

Franklin, J. E.; Ezis, A.

1994-01-01

Lightweight, oxidation-resistant silicon nitride components containing intricate internal cooling and hydraulic passages and capable of withstanding high operating temperatures made by ceramic-platelet technology. Used to fabricate silicon nitride test articles of two types: components of methane-cooled regenerator for air turbo ramjet engine and components of bipropellant injector for rocket engine. Procedures for development of more complex and intricate components established. Technology has commercial utility in automotive, aircraft, and environmental industries for manufacture of high-temperature components for use in regeneration of fuels, treatment of emissions, high-temperature combustion devices, and application in which other high-temperature and/or lightweight components needed. Potential use in fabrication of combustors and high-temperature acoustic panels for suppression of noise in future high-speed aircraft.

Expression of enzymes in yeast for lignocellulose derived oligomer CBP

DOEpatents

McBride, John E.; Wiswall, Erin; Shikhare, Indraneel; Xu, Haowen; Thorngren, Naomi; Hau, Heidi H.; Stonehouse, Emily

2017-08-29

The present invention provides a multi-component enzyme system that hydrolyzes hemicellulose oligomers from hardwood which can be expressed, for example, in yeast such as Saccharomyces cerevisiae. In some embodiments, this invention provides for the engineering of a series of biocatalysts combining the expression and secretion of components of this enzymatic system with robust, rapid xylose utilization, and ethanol fermentation under industrially relevant process conditions for consolidated bioprocessing. In some embodiments, the invention utilizes co-cultures of strains that can achieve significantly improved performance due to the incorporation of additional enzymes in the fermentation system.

Development of Personal Decontamination System Final Report CRADA No. TC-02078-04

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

Smith, W. J.; O'Dell, P.

2017-09-27

This was a collaborative effort between The Regents of the University of California, Lawrence Livermore National Laboratory (LLNL) and O’Dell Engineering, Ltd. (O’Dell) to develop an improved low-cost personal decontamination system for Toxic Industrial Chemicals (TICs) and chemical agents. The significant change to the project was that COTS (Commercial Off-the Shelf Components) were identified that performed as well, or better than, the proprietary materials created and tested as part of this CRADA. These COTS components were combined to create a new LPDS (low-cost personal decontamination system) that met all specifications.

Service evaluation of aircraft composite structural components

NASA Technical Reports Server (NTRS)

Brooks, W. A., Jr.; Dow, M. B.

1973-01-01

The advantages of the use of composite materials in structural applications have been identified in numerous engineering studies. Technology development programs are underway to correct known deficiencies and to provide needed improvements. However, in the final analysis, flight service programs are necessary to develop broader acceptance of, and confidence in, any new class of materials such as composites. Such flight programs, initiated by NASA Langley Research Center, are reviewed. These programs which include the selectively reinforced metal and the all-composite concepts applied to both secondary and primary aircraft structural components, are described and current status is indicated.

A Computational Study to Investigate the Effect of Altitude on Deteriorated Engine Performance

NASA Astrophysics Data System (ADS)

Koh, W. C.; Mazlan, N. M.; Rajendran, P.; Ismail, M. A.

2018-05-01

This study presents an investigation on the effect of operational altitudes on the performance of the deteriorated engine. A two-spool high bypass ratio turbofan engine is used as the test subject for this study. The engine is modelled in Gas Turbine Simulation Program (GSP) based on an existing engine model from literature. Real flight data were used for the validation. Deterioration rate of 0.1% per day is applied for all turbofan components engine. The simulation is performed by varying the altitude from sea level until 9000m. Results obtained show reduction in air mass flow rate and engine thrust as altitude increases. The reduction in air mass flow rate is due to the lower air density at higher altitude hence reduces amount of engine thrust. At 1000m to 4000m, thrust specific fuel consumption (TSFC) of the engine is improved compared to sea level. However depleted in TSFC is shown when the aircraft flies at altitude higher than 4000m. At this altitude, the effect of air density is dominant. As a result, the engine is required to burn more fuel to provide a higher thrust to sustain the aircraft speed. More fuel is consumed hence depletion in TSFC is obtained.

Space flight requirements for fiber optic components: qualification testing and lessons learned

NASA Astrophysics Data System (ADS)

Ott, Melanie N.; Jin, Xiaodan Linda; Chuska, Richard; Friedberg, Patricia; Malenab, Mary; Matuszeski, Adam

2006-04-01

"Qualification" of fiber optic components holds a very different meaning than it did ten years ago. In the past, qualification meant extensive prolonged testing and screening that led to a programmatic method of reliability assurance. For space flight programs today, the combination of using higher performance commercial technology, with shorter development schedules and tighter mission budgets makes long term testing and reliability characterization unfeasible. In many cases space flight missions will be using technology within years of its development and an example of this is fiber laser technology. Although the technology itself is not a new product the components that comprise a fiber laser system change frequently as processes and packaging changes occur. Once a process or the materials for manufacturing a component change, even the data that existed on its predecessor can no longer provide assurance on the newer version. In order to assure reliability during a space flight mission, the component engineer must understand the requirements of the space flight environment as well as the physics of failure of the components themselves. This can be incorporated into an efficient and effective testing plan that "qualifies" a component to specific criteria defined by the program given the mission requirements and the component limitations. This requires interaction at the very initial stages of design between the system design engineer, mechanical engineer, subsystem engineer and the component hardware engineer. Although this is the desired interaction what typically occurs is that the subsystem engineer asks the components or development engineers to meet difficult requirements without knowledge of the current industry situation or the lack of qualification data. This is then passed on to the vendor who can provide little help with such a harsh set of requirements due to high cost of testing for space flight environments. This presentation is designed to guide the engineers of design, development and components, and vendors of commercial components with how to make an efficient and effective qualification test plan with some basic generic information about many space flight requirements. Issues related to the physics of failure, acceptance criteria and lessons learned will also be discussed to assist with understanding how to approach a space flight mission in an ever changing commercial photonics industry.

Space Flight Requirements for Fiber Optic Components; Qualification Testing and Lessons Learned

NASA Technical Reports Server (NTRS)

Ott, Melanie N.; Jin, Xiaodan Linda; Chuska, Richard; Friedberg, Patricia; Malenab, Mary; Matuszeski, Adam

2007-01-01

"Qualification" of fiber optic components holds a very different meaning than it did ten years ago. In the past, qualification meant extensive prolonged testing and screening that led to a programmatic method of reliability assurance. For space flight programs today, the combination of using higher performance commercial technology, with shorter development schedules and tighter mission budgets makes long term testing and reliability characterization unfeasible. In many cases space flight missions will be using technology within years of its development and an example of this is fiber laser technology. Although the technology itself is not a new product the components that comprise a fiber laser system change frequently as processes and packaging changes occur. Once a process or the materials for manufacturing a component change, even the data that existed on its predecessor can no longer provide assurance on the newer version. In order to assure reliability during a space flight mission, the component engineer must understand the requirements of the space flight environment as well as the physics of failure of the components themselves. This can be incorporated into an efficient and effective testing plan that "qualifies" a component to specific criteria defined by the program given the mission requirements and the component limitations. This requires interaction at the very initial stages of design between the system design engineer, mechanical engineer, subsystem engineer and the component hardware engineer. Although this is the desired interaction what typically occurs is that the subsystem engineer asks the components or development engineers to meet difficult requirements without knowledge of the current industry situation or the lack of qualification data. This is then passed on to the vendor who can provide little help with such a harsh set of requirements due to high cost of testing for space flight environments. This presentation is designed to guide the engineers of design, development and components, and vendors of commercial components with how to make an efficient and effective qualification test plan with some basic generic information about many space flight requirements. Issues related to the physics of failure, acceptance criteria and lessons learned will also be discussed to assist with understanding how to approach a space flight mission in an ever changing commercial photonics industry.

Ceramic components for the AGT 100 engine

NASA Technical Reports Server (NTRS)

Helms, H. E.; Heitman, P. W.

1983-01-01

Historically, automotive gas turbines have not been able to meet requirements of the marketplace with respect to cost, performance, and reliability. However, the development of appropriate ceramic materials has overcome problems related to a need for expensive superalloy components and to limitations regarding the operating temperature. An automotive gas turbine utilizing ceramic components has been developed by a U.S. automobile manufacturer. A 100-horsepower, two-shaft, regenerative engine geometry was selected because it is compatible with manual, automatic, and continuously variable transmissions. Attention is given to the ceramic components, the ceramic gasifier turbine rotor development, the ceramic gasifier scroll, ceramic component testing, and the use of advanced nondestructive techniques for the evaluation of the engine components.