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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 991 records · Page 55
All sourcesNASA NTRSDOE OSTI
NASA NTRS1998

Engine Gaseous, Aerosol Precursor and Particulated Flight Altitude Conditions

The overall objective of the NASA Atmospheric Effects of Aviation Project (AEAP) is to develop scientific bases for assessing atmospheric impacts of the exhaust emissions by both current and future fleets of subsonic and supersonic aircraft. Among the six primary elements of the AEAP is Emissions Characterization. The objective of the Emission Characterization effort is to determine the exhaust emission constituents and concentrations at the engine exit plane. The specific objective of this engine test is to obtain a database of gaseous and particulate emissions as a function of fuel sulfur and engine operating conditions. The database of the particulate emission properties is to be used as a comparative baseline with subsequent flight measurement. The engine used in this test was a Pratt & Whitney F1OO-200E turbofan engine. Aviation fuel (Jet A) with a range of fuel sulfur was used. Low and high sulfur values are limited by commercially available fuels and by fuel specification limits of O.3% by weight. Test matrix was set by parametrically varying the combustor inlet temperature (T(sub 3) between idle and maximum power setting at simulated SLS and up to five other altitudes for each fuel. Four diagnostic systems, extractive and non-intrusive, were assembled for the gaseous and particulate emissions characterization measurements study. NASA extractive system includes smoke meter and analyzers for measurement of CO, CO2, NO, NOx, O2, total unburnt hydrocarbons (THC), and SO2. Particulate emissions were characterized by University of Missouri-Rolla Mobile Aerosol Sampling System. A chemical ionization mass spectrometer from the Air Force Research Laboratory at Hanscom AFB was used to measure SO2 and HNO3. Aerodyne Research. Inc. used infrared tunable diode laser absorption to measure SO2, SO3, NO, H2O and CO2.

Wey, C. C.↗
NASA NTRS1998

Uncertainty in Calibration, Detection and Estimation of Metal Concentrations in Engine Plumes Using OPAD

Improvements in uncertainties in the values of radiant intensity (I) can be accomplished mainly by improvements in the calibration process and in minimizing the difference between the background and engine plume radiance. For engine tests in which the plume is extremely bright, the difference in luminance between the calibration lamp and the engine plume radiance can be so large as to cause relatively large uncertainties in the values of R. This is due to the small aperture necessary on the receiving optics to avoid saturating the instrument. However, this is not a problem with the SSME engine since the liquid oxygen/hydrogen combustion is not as bright as some other fuels. Applying the instrumentation to other type engine tests may require a much brighter calibration lamp.

Hopkins, Randall C.↗
NASA NTRS1998

1998 NASA-HU American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program

Since 1964, the National Aeronautics and Space Administration (NASA) has supported a program of summer faculty fellowships for engineering and science educators. In a series of collaborations between NASA research and development centers and nearby universities, engineering faculty members spend 10 weeks working with professional peers on research. The Summer Faculty Program Committee of the American Society for Engineering Education supervises the programs. The program objectives include: (1) To further the professional knowledge of qualified engineering and science faculty members; (2) To stimulate and exchange ideas between participants and NASA; (3) To enrich and refresh the research and teaching activities of participants' institutions; (4) To contribute to the research objectives of the NASA center. College or university faculty members will be appointed as Research Fellows to spend 10 weeks in cooperative research and study at the NASA Langley Research Center. The Fellow will devote approximately 90 percent of the time to a research problem and the remaining time to a study program. The study program will consist of lectures and seminars on topics of interest or that are directly relevant to the Fellows' research topics. The lecture and seminar leaders will be distinguished scientists and engineers from NASA, education, and industry.

Marable, William P.↗
NASA NTRS1999

Factors Affecting Inlet-Engine Compatibility During Aircraft Departures at High Angle of Attack for an F/A -18A Aircraft

The F404-GE-400 engine powered F/A- 18A High Alpha Research Vehicle (HARV) was used to examine the quality of inlet airflow during departed flight maneuvers, that is, during flight outside the normal maneuvering envelope where control surfaces have little or no effectiveness. A series of six nose-left and six nose-right departures were initiated at Mach numbers between 0.3 and 0.4 at an altitude of 35 kft. The yaw rates at departure recovery were in the range of 40 to 90 degrees per second. Engine surges were encountered during three of the nose-left and one of the nose-right departures. Time-variant inlet-total-pressure distortion levels at the engine face were determined to not significantly exceed those measured at maximum angle-of-attack and - sideslip maneuvers during controlled flight. Surges as a result of inlet distortion levels were anticipated to initiate in the fan. Analysis revealed that the surges initiated in the compressor and were the result of a combination of high levels of inlet distortion and rapid changes in aircraft motion. These rapid changes in aircraft motion are indicative of a combination of engine mount and gyroscopic loads being applied to the engine structure that impact the aerodynamic stability of the compressor through changes in the rotor-to-case clearances.

Steenken, W. G.↗
NASA NTRS1998

Industrial Engineering Lifts Off at Kennedy Space Center

When the National Aeronautics and Space Administration (NASA) began the Space Shuttle Program, it did not have an established industrial engineering (IE) capability for several probable reasons. For example, it was easy for some managers to dismiss IE principles as being inapplicable at NASA's John F. Kennedy Space Center (KSC). When NASA was formed by the National Aeronautics and Space Act of 1958, most industrial engineers worked in more traditional factory environments. The primary emphasis early in the shuttle program, and during previous human space flight programs such as Mercury and Apollo, was on technical accomplishments. Industrial engineering is sometimes difficult to explain in NASA's highly technical culture. IE is different in many ways from other engineering disciplines because it is devoted to process management and improvement, rather than product design. Images of clipboards and stopwatches still come to the minds of many people when the term industrial engineering is mentioned. The discipline of IE has only recently begun to gain acceptance and understanding in NASA. From an IE perspective today, the facilities used for flight hardware processing at KSC are NASA's premier factories. The products of these factories are among the most spectacular in the world: safe and successful launches of shuttles and expendable vehicles that carry tremendous payloads into space.

Barth, Tim↗
NASA NTRS1999

Active Control of Inlet Noise on the JT15D Turbofan Engine

This report presents the key results obtained by the Vibration and Acoustics Laboratories at Virginia Tech over the year from November 1997 to December 1998 on the Active Noise Control of Turbofan Engines research project funded by NASA Langley Research Center. The concept of implementing active noise control techniques with fuselage-mounted error sensors is investigated both analytically and experimentally. The analytical part of the project involves the continued development of an advanced modeling technique to provide prediction and design guidelines for application of active noise control techniques to large, realistic high bypass engines of the type on which active control methods are expected to be applied. Results from the advanced analytical model are presented that show the effectiveness of the control strategies, and the analytical results presented for fuselage error sensors show good agreement with the experimentally observed results and provide additional insight into the control phenomena. Additional analytical results are presented for active noise control used in conjunction with a wavenumber sensing technique. The experimental work is carried out on a running JT15D turbofan jet engine in a test stand at Virginia Tech. The control strategy used in these tests was the feedforward Filtered-X LMS algorithm. The control inputs were supplied by single and multiple circumferential arrays of acoustic sources equipped with neodymium iron cobalt magnets mounted upstream of the fan. The reference signal was obtained from an inlet mounted eddy current probe. The error signals were obtained from a number of pressure transducers flush-mounted in a simulated fuselage section mounted in the engine test cell. The active control methods are investigated when implemented with the control sources embedded within the acoustically absorptive material on a passively-lined inlet. The experimental results show that the combination of active control techniques with fuselage-mounted error sensors and passive control techniques is an effective means of reducing radiated noise from turbofan engines. Strategic selection of the location of the error transducers is shown to be effective for reducing the radiation towards particular directions in the farfield. An analytical model is used to predict the behavior of the control system and to guide the experimental design configurations, and the analytical results presented show good agreement with the experimentally observed results.

Smith, Jerome P.↗
NASA NTRS1999

System Engineering Issues for Avionics Survival in the Space Environment

This paper examines how the system engineering process influences the design of a spacecraft's avionics by considering the space environment. Avionics are susceptible to the thermal, radiation, plasma, and meteoroids/orbital debris environments. The environment definitions for various spacecraft mission orbits (LEO/low inclination, LEO/Polar, MEO, HEO, GTO, GEO and High ApogeeElliptical) are discussed. NASA models and commercial software used for environment analysis are reviewed. Applicability of technical references, such as NASA TM-4527 "Natural Orbital Environment Guidelines for Use in Aerospace Vehicle Development" is discussed. System engineering references, such as the MSFC System Engineering Handbook, are reviewed to determine how the environments are accounted for in the system engineering process. Tools and databases to assist the system engineer and avionics designer in addressing space environment effects on avionics are described and usefulness assessed.

Pavelitz, Steven↗
NASA NTRS1999

Investigation of NOx Removal from Small Engine Exhaust

Contribution of emissions from small engines to the air pollution is significant. Due to differences in operating conditions and economics, the pollution control systems designed for automobiles will be neither suitable nor economically feasible for use on small engines. The objective of this project was to find a catalyst for the removal of NOx from the exhaust of small engines which use a rich air to fuel ratio. The desired catalyst should be inexpensive so that the cost of the pollution control unit will be only a small fraction of the total equipment cost. The high cost of noble metals makes them too expensive for use as NOx catalyst for small engines. Catalytic reduction of Nitrogen Oxide (NO) can also be accomplished by base-metal oxide catalysts. The main disadvantage of base-metal catalysts is their deactivation by poisons and high temperatures. Requirements for the length of the life of the small engine exhaust catalysts are much less than those for automobile exhaust catalysts. Since there is no oxygen in the exhaust gases, reduction selectivity is not a problem. Also, the reducing exhaust gases might help prevent the harmful interactions of the catalyst with the support. For these reasons only the supported metal oxide catalysts were investigated in this project.

Akyurtlu, Ates↗
NASA NTRS1999

Investigation of NO(x) Removal from Small Engine Exhaust

Contribution of emissions from small engines to the air pollution is significant. Due to differences in operating conditions and economics, the pollution control systems designed for automobiles will be neither suitable nor economically feasible for use on small engines. The objective of this project was to find a catalyst for the removal of NOx from the exhaust of small engines which use a rich air to fuel ratio. The desired catalyst should be inexpensive so that the cost of the pollution control unit will be only a small fraction of the total equipment cost. The high cost of noble metals makes them too expensive for use as NOx catalyst for small engines. Catalytic reduction of NO can also be accomplished by base-metal oxide catalysts. The main disadvantage of base-metal catalysts is their deactivation by poisons and high temperatures. Requirements for the length of the life of the small engine exhaust catalysts are much less than those for automobile exhaust catalysts. Since there is no oxygen in the exhaust gases, reduction selectivity is not a problem. Also, the reducing exhaust gases might help prevent the harmful interactions of the catalyst with the support. For these reasons only the supported metal oxide catalysts were investigated in this project.

Akyurtlu, Ates↗
NASA NTRS2000

NASA Fastrac Engine Gas Generator Component Test Program and Results

Low cost access to space has been a long-time goal of the National Aeronautics and Space Administration (NASA). The Fastrac engine program was begun at NASA's Marshall Space Flight Center to develop a 60,000-pound (60K) thrust, liquid oxygen/hydrocarbon (LOX/RP), gas generator-cycle booster engine for a fraction of the cost of similar engines in existence. To achieve this goal, off-the-shelf components and readily available materials and processes would have to be used. This paper will present the Fastrac gas generator (GG) design and the component level hot-fire test program and results. The Fastrac GG is a simple, 4-piece design that uses well-defined materials and processes for fabrication. Thirty-seven component level hot-fire tests were conducted at MSFC's component test stand #116 (TS116) during 1997 and 1998. The GG was operated at all expected operating ranges of the Fastrac engine. Some minor design changes were required to successfully complete the test program as development issues arose during the testing. The test program data results and conclusions determined that the Fastrac GG design was well on the way to meeting the requirements of NASA's X-34 Pathfinder Program that chose the Fastrac engine as its main propulsion system.

Dennis, Henry J., Jr.↗
NASA NTRS2000

Putting ROSE to Work: A Proposed Application of a Request-Oriented Scheduling Engine for Space Station Operations

Scheduling engines are found at the core of software systems that plan and schedule activities and resources. A Request-Oriented Scheduling Engine (ROSE) is one that processes a single request (adding a task to a timeline) and then waits for another request. For the International Space Station, a robust ROSE-based system would support multiple, simultaneous users, each formulating requests (defining scheduling requirements), submitting these requests via the internet to a single scheduling engine operating on a single timeline, and immediately viewing the resulting timeline. ROSE is significantly different from the engine currently used to schedule Space Station operations. The current engine supports essentially one person at a time, with a pre-defined set of requirements from many payloads, working in either a "batch" scheduling mode or an interactive/manual scheduling mode. A planning and scheduling process that takes advantage of the features of ROSE could produce greater customer satisfaction at reduced cost and reduced flow time. This paper describes a possible ROSE-based scheduling process and identifies the additional software component required to support it. Resulting changes to the management and control of the process are also discussed.

Jaap, John↗
NASA NTRS1999

Space Shuttle Orbital Maneuvering Subsystem (OMS) Engine Propellant Leakage Ball-Valve Shaft Seals

Evidence of propellant leakage across ball-valve shaft seals has been noted during the disassembly of five flight engines and one test engine at the NASA Lyndon B. Johnson Space Center, White Sands Test Facility. Based on data collected during the disassembly of these five engines, the consequences of propellant leakage across the ball-valve shaft seals can be divided into four primary areas of concern: Damage to the ball-valve pinion shafts, damage to sleeved bearings inside the ball-valve and actuator assemblies, degradation of the synthetic rubber o-rings used in the actuator assemblies, and corrosion and degradation to the interior of the actuator assemblies. The exact time at which leakage across the ball-valve shaft seals occurs has not been determined, however, the leakage most likely occurs during engine firings when, depending on the specification used, ball-valve cavity pressures range as high as 453 to 550 psia. This potential pressure range for the ball-valve cavities greatly exceeds the acceptance leakage test pressure of 332 psia. Since redesign and replacement of the ball-valve shaft seals is unlikely, the near term solution to prevent damage that occurs from shaft-seal leakage is to implement a routine overhaul and maintenance program for engines in the fleet. Recommended repair, verification, and possible preventative maintenance measures are discussed in the paper.

Lueders, Kathy↗
NASA NTRS2000

Development Status of the NASA MC-1 (Fastrac) Engine

The MC-1 (formerly known as the Fastrac 60K) Engine is being developed for the X-34 technology demonstrator vehicle. It is a pump-fed liquid rocket engine with fixed thrust operating at one rated power level of 60,000 lbf vacuum thrust using a 15:1 area ratio nozzle (slightly higher for the 30:1 flight nozzle). Engine system development testing of the MC-1 has been ongoing since 24 Oct 1998. To date, 48 tests have been conducted on three engines using three separate test stands. This paper will provide some details of the engine, the tests conducted, and the lessons learned to date.

Ballard, Richard O.↗
NASA NTRS2000

1999 NASA - ODU American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program

Since 1964, the National Aeronautics and Space Administration (NASA) has supported a program or summer faculty fellowships for engineering and science educators. In a series of collaborations between NASA research and development centers and nearby universities, engineering faculty members spend 10 weeks working with professional peers on research. The Summer Faculty Program Committee of the American Society for Engineering Education supervises the programs. Objectives: (1) To further the professional knowledge of qualified engineering and science faculty members; (2) To stimulate and exchange ideas between participants and NASA; (3) To enrich and refresh the research and teaching activities of participants' institutions; (4) To contribute to the research objectives of the NASA center. Program Description: College or university faculty members will be appointed as Research Fellows to spend 10 weeks in cooperative research and study at the NASA Langley Research Center. The Fellow will devote approximately 90 percent of the time to a research problem and the remaining time to a study program. The study program will consist of lectures and seminars on topics of interest or that are directly relevant to the Fellows' research topics. The lecture and seminar leaders will be distinguished scientists and engineers from NASA, education, and industry.

Tiwari, Surendra N.↗
NASA NTRS2000

2000 NASA-HU American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program

Since 1964, the National Aeronautics and Space Administration (NASA) has supported a program of summer faculty fellowships for engineering and science educators. In a series of collaborations between NASA research and development centers and nearby universities, engineering faculty members spend ten weeks working with professional peers on research. The Summer Faculty Program Committee of the American Society for Engineering Education supervises the programs. The objectives are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate and exchange ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants' institutions; and (4) to contribute to the research objectives of the NASA center. College or university faculty members will be appointed as Research Fellows to spend ten weeks in cooperative research and study at the NASA Langley Research Center. The Fellow will devote approximately 90 percent of the time to a research problem and the remaining time to a study program. The study program will consist of lectures and seminars on topics of interest or that are directly relevant to the Fellows' research topics. The lecture and seminar leaders will be distinguished scientists and engineers from NASA, education, and industry. A list of the abstracts of the presentations is provided.

Marable, William P.↗
NASA NTRS1997

Minority Universities Systems Engineering (MUSE) Program at the University of Texas at El Paso

In 1995, The University of Texas at El Paso (UTEP) responded to the suggestion of NASA Jet Propulsion Laboratory (NASA JPL) to form a consortium comprised of California State University at Los Angeles (CSULA), North Carolina Agricultural and Technical University (NCAT), and UTEP from which developed the Minority Universities Systems Engineering (MUSE) Program. The mission of this consortium is to develop a unique position for minority universities in providing the nation's future system architects and engineers as well as enhance JPL's system design capability. The goals of this collaboration include the development of a system engineering curriculum which includes hands-on project engineering and design experiences. UTEP is in a unique position to take full advantage of this program since UTEP has been named a Model Institution for Excellence (MIE) by the National Science Foundation. The purpose of MIE is to produce leaders in Science, Math, and Engineering. Furthermore, UTEP has also been selected as the site for two new centers including the Pan American Center for Earth and Environmental Sciences (PACES) directed by Dr. Scott Starks and the FAST Center for Structural Integrity of Aerospace Systems directed by Dr. Roberto Osegueda. The UTEP MUSE Program operates under the auspices of the PACES Center.

Robbins, Mary Clare↗
NASA NTRS2001

Aircraft Engine Systems

This report outlines the detailed simulation of Aircraft Turbofan Engine. The objectives were to develop a detailed flow model of a full turbofan engine that runs on parallel workstation clusters overnight and to develop an integrated system of codes for combustor design and analysis to enable significant reduction in design time and cost. The model will initially simulate the 3-D flow in the primary flow path including the flow and chemistry in the combustor, and ultimately result in a multidisciplinary model of the engine. The overnight 3-D simulation capability of the primary flow path in a complete engine will enable significant reduction in the design and development time of gas turbine engines. In addition, the NPSS (Numerical Propulsion System Simulation) multidisciplinary integration and analysis are discussed.

Veres, Joseph↗
NASA NTRS1993

Engine Lubricant

PS 212, a plasma-sprayed coating developed by NASA, is used to coat valves in a new rotorcam engine. The coating eliminates the need for a liquid lubricant in the rotorcam, which has no crankshaft, flywheel, distributor or water pump. Developed by Murray United Development Corporation, it is a rotary engine only 10 inches long with four cylinders radiating outward from a central axle. Company officials say the engine will be lighter, more compact and cheaper to manufacture than current engines and will feature cleaner exhaust emissions. A licensing arrangement with a manufacturer is under negotiation. Primary applications are for automobiles, but the engine may also be used in light aircraft.

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