Science.gov

Sample records for aircraft piston engines

  1. Aircraft Piston Engine Exhaust Emission Symposium

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A 2-day symposium on the reduction of exhaust emissions from aircraft piston engines was held on September 14 and 15, 1976, at the Lewis Research Center in Cleveland, Ohio. Papers were presented by both government organizations and the general aviation industry on the status of government contracts, emission measurement problems, data reduction procedures, flight testing, and emission reduction techniques.

  2. TCM aircraft piston engine emission reduction program

    NASA Technical Reports Server (NTRS)

    Rezy, B. J.

    1976-01-01

    The technology necessary to safely reduce general aviation piston engine exhaust emissions to meet the EPA 1980 Emission Standards with minimum adverse effects on cost, weight, fuel economy, and performance was demonstrated. A screening and assessment of promising emission reduction concepts was provided, and the preliminary design and development of those concepts was established. A system analysis study and a decision making procedure were used by TCM to evaluate, trade off, and rank the candidate concepts from a list of 14 alternatives. Cost, emissions, and 13 other design criteria considerations were defined and traded off against each candidate concept to establish its merit and emission reduction usefulness. A computer program was used to aid the evaluators in making the final choice of three concepts.

  3. Advanced Technology Spark-Ignition Aircraft Piston Engine Design Study

    NASA Technical Reports Server (NTRS)

    Stuckas, K. J.

    1980-01-01

    The advanced technology, spark ignition, aircraft piston engine design study was conducted to determine the improvements that could be made by taking advantage of technology that could reasonably be expected to be made available for an engine intended for production by January 1, 1990. Two engines were proposed to account for levels of technology considered to be moderate risk and high risk. The moderate risk technology engine is a homogeneous charge engine operating on avgas and offers a 40% improvement in transportation efficiency over present designs. The high risk technology engine, with a stratified charge combustion system using kerosene-based jet fuel, projects a 65% improvement in transportation efficiency. Technology enablement program plans are proposed herein to set a timetable for the successful integration of each item of required advanced technology into the engine design.

  4. Investigation of the misfueling of reciprocating piston aircraft engines

    NASA Technical Reports Server (NTRS)

    Scott, J. Holland, Jr.

    1988-01-01

    The Aircraft Misfueling Detection Project was developed by the Goddard Space Flight Center/Wallops Flight Facility at Wallops Island, Virginia. Its purpose was to investigate the misfueling of reciprocating piston aircraft engines by the inadvertent introduction of jet fuel in lieu of or as a contaminant of aviation gasoline. The final objective was the development of a device(s) that will satisfactorily detect misfueling and provide pilots with sufficient warning to avoid injury, fatality, or equipment damage. Two devices have been developed and successfully tested: one, a small contamination detection kit, for use by the pilot, and a second, more sensitive, modified gas chromatograph for use by the fixed-base operator. The gas chromatograph, in addition to providing excellent quality control of the fixed-base operator's fuel handling, is a very good backup for the detection kit in the event it produces negative results. Design parameters were developed to the extent that they may be applied easily to commercial production by the aircraft industry.

  5. Development of EPA aircraft piston engine emission standards. [for air quality

    NASA Technical Reports Server (NTRS)

    Houtman, W.

    1976-01-01

    Piston engine light aircraft are significant sources of carbon monoxide in the vicinity of high activity general aviation airports. Substantial reductions in carbon monoxide were achieved by fuel mixture leaning using improved fuel management systems. The air quality impact of the hydrocarbon and oxides of nitrogen emissions from piston engine light aircraft were insufficient to justify the design constraints being confronted in present control system developments.

  6. Avco Lycoming/NASA contract status. [on reduction of emissions from aircraft piston engines

    NASA Technical Reports Server (NTRS)

    Duke, L. C.

    1976-01-01

    The standards promulgated by the Environmental Protection Agency (EPA) for carbon monoxide (CO), unburned hydrocarbon (HC), and oxides-of-nitrogen (NOx) emissions were the basis in a study of ways to reduce emissions from aircraft piston engines. A variable valve timing system, ultrasonic fuel atomization, and ignition system changes were postulated.

  7. Summary of the general aviation manufacturers' position on aircraft piston engine emissions

    NASA Technical Reports Server (NTRS)

    Helms, J. L.

    1976-01-01

    The General Aviation Manufacturers recommended that the EPA rescind the aircraft piston engine emissions regulations currently on the books. The reason was the very small emission reduction potential and the very poor benefit-cost ratio involved in this form of emission reduction. The limited resources of this industry can far better be devoted to items of much greater benefit to the citizens of this country - reducing noise, improving fuel efficiency (which will incidently reduce exhaust emissions), and improving the safety, operational, and economic aspects of aircraft, all far greater contributions to our total national transportation system.

  8. Free piston stirling engines

    SciTech Connect

    Walker, C.

    1985-01-01

    This book presents a basic introduction to free piston Stirling engine technology through a review of specialized background material. It also includes information based on actual construction and operation experience with these machines, as well as theoretical and analytical insights into free piston Stirling engine technology.

  9. Stirling engine piston ring

    DOEpatents

    Howarth, Roy B.

    1983-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  10. Causes and risk factors for fatal accidents in non-commercial twin engine piston general aviation aircraft.

    PubMed

    Boyd, Douglas D

    2015-04-01

    Accidents in twin-engine aircraft carry a higher risk of fatality compared with single engine aircraft and constitute 9% of all general aviation accidents. The different flight profile (higher airspeed, service ceiling, increased fuel load, and aircraft yaw in engine failure) may make comparable studies on single-engine aircraft accident causes less relevant. The objective of this study was to identify the accident causes for non-commercial operations in twin engine aircraft. A NTSB accident database query for accidents in twin piston engine airplanes of 4-8 seat capacity with a maximum certified weight of 3000-8000lbs. operating under 14CFR Part 91 for the period spanning 2002 and 2012 returned 376 accidents. Accident causes and contributing factors were as per the NTSB final report categories. Total annual flight hour data for the twin engine piston aircraft fleet were obtained from the FAA. Statistical analyses employed Chi Square, Fisher's Exact and logistic regression analysis. Neither the combined fatal/non-fatal accident nor the fatal accident rate declined over the period spanning 2002-2012. Under visual weather conditions, the largest number, n=27, (27%) of fatal accidents was attributed to malfunction with a failure to follow single engine procedures representing the most common contributing factor. In degraded visibility, poor instrument approach procedures resulted in the greatest proportion of fatal crashes. Encountering thunderstorms was the most lethal of all accident causes with all occupants sustaining fatal injuries. At night, a failure to maintain obstacle/terrain clearance was the most common accident cause leading to 36% of fatal crashes. The results of logistic regression showed that operations at night (OR 3.7), off airport landings (OR 14.8) and post-impact fire (OR 7.2) all carried an excess risk of a fatal flight. This study indicates training areas that should receive increased emphasis for twin-engine training/recency. First, increased

  11. Reciprocating piston engine

    SciTech Connect

    White, A.

    1986-09-02

    This patent describes a reciprocating piston engine wherein there is included the combination of one or more pistons individually reciprocatably mounted each within a cylinder, an intake valve located within a cylinder through which fuel and air can be admitted into the cylinder, compressed and the fuel burned to drive a piston during a power stroke, an exhaust valve located within a cylinder through which burned fuel can be exhausted by movement of a piston to expell the burned gases during an exhaust stroke, a piston having a crown side and a side opposite the crown side to which a piston shaft is attached, the crown side of the piston facing into the cylinder wherein the intake and exhaust valves are located, an elongated roller gear to which the piston shaft is attached, the elongated roller gear is open centered and has an inside face thereof provided with a continuous array of teeth, a drive shaft, a roller gear pinion operatively engaged with the drive shaft, rotation of which produces rotation of the drive shaft, the roller gear pinion being provided with a continuous array of teeth for continuous meshing engagement with the teeth on the inside face of the elongated roller gear, movement of a piston acting through a piston shaft and elongated roller gear producing rotation of the drive shaft via action upon roller gear pinion, the impovement comprising, in the combination, a pair of rails, one each of which is disposed on opposite sides of the teeth of the elongated roller gear, a pair of rollers, one each of which is disposed on opposite sides adjacent and parallel to the teeth of roller gear pinion, the rollers of the roller gear pinion contacting and rolling along the rails of the elongated roller gear to maintain a proper relationship and root clearance between the meshing teeth of an elongated roller gear and a roller gear pinion for effecting the continuous rolling and meshing engagement.

  12. Free-piston engine

    DOEpatents

    Van Blarigan, Peter

    2001-01-01

    A combustion system which can utilize high compression ratios, short burn durations, and homogeneous fuel/air mixtures in conjunction with low equivalence ratios. In particular, a free-piston, two-stroke autoignition internal combustion engine including an electrical generator having a linear alternator with a double-ended free piston that oscillates inside a closed cylinder is provided. Fuel and air are introduced in a two-stroke cycle fashion on each end, where the cylinder charge is compressed to the point of autoignition without spark plugs. The piston is driven in an oscillating motion as combustion occurs successively on each end. This leads to rapid combustion at almost constant volume for any fuel/air equivalence ratio mixture at very high compression ratios. The engine is characterized by high thermal efficiency and low NO.sub.x emissions. The engine is particularly suited for generating electrical current in a hybrid automobile.

  13. Free-piston engine

    SciTech Connect

    Hammett, R.B.

    1992-09-08

    This patent describes an apparatus utilizing energy to pump gas. It comprises a piston fitted to a using, a pressure chamber to one side of the piston comprising means to increase the pressure or volume of gas in the pressure chamber to cause outward acceleration of the piston; a rebounding vole to the other side of the piston opposing the outward movement of the piston by the gas pressure in the rebounding volume; and an outlet port in the casing located so as to be uncovered by the piston substantially before the piston has reached the outward end of the stroke of the piston.

  14. Ultralean combustion in general aviation piston engines

    NASA Technical Reports Server (NTRS)

    Chirivella, J. E.

    1979-01-01

    The role of ultralean combustion in achieving fuel economy in general aviation piston engines was investigated. The aircraft internal combustion engine was reviewed with regard to general aviation requirements, engine thermodynamics and systems. Factors affecting fuel economy such as those connected with an ideal leanout to near the gasoline lean flammability limit (ultralean operation) were analyzed. A Lycoming T10-541E engine was tested in that program (both in the test cell and in flight). Test results indicate that hydrogen addition is not necessary to operate the engine ultralean. A 17 percent improvement in fuel economy was demonstrated in flight with the Beechcraft Duke B60 by simply leaning the engine at constant cruiser power and adjusting the ignition for best timing. No detonation was encountered, and a 25,000 ft ceiling was available. Engine roughness was shown to be the limiting factor in the leanout.

  15. Piston and spring powered engine

    SciTech Connect

    Samodovitz, A. J.

    1985-12-10

    The invention is an improved piston engine, either two stroke or four stroke. In one, two stroke, one cylinder embodiment, the improvement comprises two springs connecting between the piston and the base of the piston. These springs are relatively relaxed when the crank is at top dead center. Then during the power/intake stroke, some of the fuel's energy is delivered to the crankshaft and some is used to compress the springs. The stored energy in the springs is delivered to the crankshaft during the exhaust/compression stroke while the springs return to their relatively relaxed condition. As a result, energy is delivered to the crankshaft during both strokes of the cycle, and the engine runs smooth. In one, four stroke, two cylinder embodiment, each cylinder has springs as described above, the cranks of each cylinder are aligned, and the cam sets one cylinder in the power stroke while the other is in the intake stroke. As a result, the engine runs smooth because energy is delivered to the crankshaft during all four strokes of the cycle, during two of the strokes by the burning fuel and during the other two by the release of energy in the springs. In both embodiments, a heavy crankshaft is not needed because of the more uniform power delivery.

  16. Rotary piston engine

    SciTech Connect

    Sakita, M.

    1992-07-28

    This patent describes an internal combustion engine including a housing forming a cylindrical working chamber having inlet and exhaust ports. This patent describes at least two more pairs of interconnected eccentric elliptical gears in the gear train between the first and second pairs of elliptical gears in substantially the same phased relationship with the first and second pairs of elliptical gears. This patent also describes a gear set for coupling first and second shafts having parallel extending axes. It comprises: first and second compound eccentric elliptical gears adapted for rotation about the first and second shaft axes, generally radially extending intermeshing teeth on the gears, generally axially extending teeth in an eccentric elliptical pattern at at least one face of the first and second gears, and an idler gear rotatable about an axis which intersects the first and second shaft axes and meshing with axially extending teeth of the first and second gears.

  17. Two piston V-type Stirling engine

    SciTech Connect

    Corey, John A.

    1987-01-01

    A two piston Stirling engine which includes a heat exchanger arrangement placing the cooler and regenerator directly adjacent the compression space for minimal cold duct volume; a sealing arrangement which eliminates the need for piston seals, crossheads and piston rods; and a simplified power control system.

  18. Staged combustion with piston engine and turbine engine supercharger

    DOEpatents

    Fischer, Larry E.; Anderson, Brian L.; O'Brien, Kevin C.

    2011-11-01

    A combustion engine method and system provides increased fuel efficiency and reduces polluting exhaust emissions by burning fuel in a two-stage combustion system. Fuel is combusted in a piston engine in a first stage producing piston engine exhaust gases. Fuel contained in the piston engine exhaust gases is combusted in a second stage turbine engine. Turbine engine exhaust gases are used to supercharge the piston engine.

  19. Staged combustion with piston engine and turbine engine supercharger

    DOEpatents

    Fischer, Larry E.; Anderson, Brian L.; O'Brien, Kevin C.

    2006-05-09

    A combustion engine method and system provides increased fuel efficiency and reduces polluting exhaust emissions by burning fuel in a two-stage combustion system. Fuel is combusted in a piston engine in a first stage producing piston engine exhaust gases. Fuel contained in the piston engine exhaust gases is combusted in a second stage turbine engine. Turbine engine exhaust gases are used to supercharge the piston engine.

  20. Double acting stirling engine piston ring

    DOEpatents

    Howarth, Roy B.

    1986-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  1. 75 FR 22439 - Advance Notice of Proposed Rulemaking on Lead Emissions From Piston-Engine Aircraft Using Leaded...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ...EPA is issuing this Advance Notice of Proposed Rulemaking (ANPR) to describe information currently available and information being collected that will be used by the Administrator to issue a subsequent proposal regarding whether, in the Administrator's judgment, aircraft lead emissions from aircraft using leaded aviation gasoline (avgas) cause or contribute to air pollution which may......

  2. Carbon/Carbon Pistons for Internal Combustion Engines

    NASA Technical Reports Server (NTRS)

    Taylor, A. H.

    1986-01-01

    Carbon/carbon piston performs same function as aluminum pistons in reciprocating internal combustion engines while reducing weight and increasing mechanical and thermal efficiencies of engine. Carbon/carbon piston concept features low piston-to-cylinder wall clearance - so low piston rings and skirts unnecessary. Advantages possible by negligible coefficient of thermal expansion of carbon/carbon.

  3. General aviation piston-engine exhaust emission reduction

    NASA Technical Reports Server (NTRS)

    Kempke, E. E., Jr.; Houtman, W. H.; Westfield, W. T.; Duke, L. C.; Rezy, B. J.

    1977-01-01

    To support the promulgation of aircraft regulations, two airports were examined, Van Nuys and Tamiami. It was determined that the carbon monoxide (CO) emissions from piston-engine aircraft have a significant influence on the CO levels in the ambient air in and around airports, where workers and travelers would be exposed. Emissions standards were set up for control of emissions from aircraft piston engines manufactured after December 31, 1979. The standards selected were based on a technologically feasible and economically reasonable control of carbon monoxide. It was concluded that substantial CO reductions could be realized if the range of typical fuel-air ratios could be narrowed. Thus, improvements in fuel management were determined as reasonable controls.

  4. Exhaust Emissions Characteristics for a General Aviation Light-Aircraft Teledyne Continental Motors (TCM) GTSIO-520-K Piston Engine.

    DTIC Science & Technology

    1979-12-01

    Testing 2 TCM GTSIO-520-K Engine Installation--NAFEC General 4 Aviation Pistion Engine Test Facility 3 NAFEC Air Induction (Airflow Measurement...adjusting the restriction on the capillary. The clamp compression was affected by the flexible material on which the clamp was mounted and the variable...General aviation pistion engine emission tests were conducted to provide the following categories of data: 1. Full-rich (or production fuel schedule

  5. Effect of Volatility on Air-Fuel Ratio Distribution and Torque Output of a Carbureted Light Aircraft Piston Engine.

    DTIC Science & Technology

    1982-03-01

    Positive displacement fuel flow sensor Burette type volumetric fuel flowmeter(2) Meriam laminar airflow meter Lamdascan air-fuel ratio meter Lebow inline...therefore the resulting data was not utilized. The volumetric flowrate of engine intake air was calculated from the pressure drop across a Meriam Model 50MC2

  6. Piston rod seal for a Stirling engine

    SciTech Connect

    Shapiro, Wilbur

    1984-01-01

    In a piston rod seal for a Stirling engine, a hydrostatic bearing and differential pressure regulating valve are utilized to provide for a low pressure differential across a rubbing seal between the hydrogen and oil so as to reduce wear on the seal.

  7. Balancing mechanism for reciprocating piston engine

    SciTech Connect

    Murata, N.; Ogino, T.

    1987-04-14

    This patent describes a balancing mechanism for a reciprocating piston internal combustion engine which includes a cylinder, a piston reciprocatable in the cylinder, a crankcase, a crankshaft mounted in the crankshaft, a crankpin connected to the piston, and a pair of crank arms bridging the crankshaft and crankpin. The crank arms and crankpin rotate with the crankshaft during operation and form a rotating mass. The balancing mechanism comprises at least one rotating counterweight attached to and rotating with the crankshaft, and eccentric journal means on the crankshaft adjacent the crank arms, rotating with the crankshaft. The journal means has an axis spaced to the side of the crankshaft axis which is opposite from the crankpin. The rotating counterweight and the eccentric journal means counterbalancing the rotating mass.

  8. Free-piston Sirling engine technology development

    NASA Astrophysics Data System (ADS)

    Dochat, G. R.

    1982-03-01

    The program will utilize the Technology Demonstrator Engine system as a test bed to evaluate specific loss mechanisms within the engine during operation. This will provide meaningful information and test data to increase understanding of free-piston operation, and will be of benefit to application development programs for heat-activated heat pumps, fluid pumps, engine generators, etc. The evaluation will include the current analytical procedures for calculating the specific losses, perform a series of tests designed to isolate each loss, comparison of actual changes in engine performance with predicted change, and in engine performance with predicted change, and to determine the adequacy of present analytical methods. Recommendations to improve overall engine/system performance and/or analytical methods will be made.

  9. Improving Free-Piston Stirling Engine Specific Power

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell H.

    2015-01-01

    This work uses analytical methods to demonstrate the potential benefits of optimizing piston and/or displacer motion in a Stirling engine. Isothermal analysis was used to show the potential benefits of ideal motion in ideal Stirling engines. Nodal analysis is used to show that ideal piston and displacer waveforms are not optimal in real Stirling engines. Constrained optimization was used to identify piston and displacer waveforms that increase Stirling engine specific power.

  10. Improving Free-Piston Stirling Engine Specific Power

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell Henry

    2014-01-01

    This work uses analytical methods to demonstrate the potential benefits of optimizing piston and/or displacer motion in a Stirling Engine. Isothermal analysis was used to show the potential benefits of ideal motion in ideal Stirling engines. Nodal analysis is used to show that ideal piston and displacer waveforms are not optimal in real Stirling engines. Constrained optimization was used to identify piston and displacer waveforms that increase Stirling engine specific power.

  11. Piston

    DOEpatents

    Donahue, Richard J.

    2007-12-04

    A number of embodiments of a piston may have a shape that provides enhanced piston guidance. In such embodiments, the piston shape may include an axial profile that is configured to provide certain thrust load characteristics.

  12. Piston

    DOEpatents

    Donahue, Richard J.

    2009-03-24

    A number of embodiments of a piston may have a shape that provides enhanced piston guidance. In such embodiments, the piston shape may include an axial profile that is configured to provide certain thrust load characteristics.

  13. Piston

    DOEpatents

    Donahue, Richard J.

    2007-11-13

    A number of embodiments of a piston may have a shape that provides enhanced piston guidance. In such embodiments, the piston shape may include an axial profile that is configured to provide certain thrust load characteristics.

  14. Piston

    DOEpatents

    Donahue, Richard J.

    2009-02-24

    A number of embodiments of a piston may have a shape that provides enhanced piston guidance. In such embodiments, the piston shape may include an axial profile that is configured to provide certain thrust load characteristics.

  15. Stability analysis of free piston Stirling engines

    NASA Astrophysics Data System (ADS)

    Bégot, Sylvie; Layes, Guillaume; Lanzetta, François; Nika, Philippe

    2013-03-01

    This paper presents a stability analysis of a free piston Stirling engine. The model and the detailed calculation of pressures losses are exposed. Stability of the machine is studied by the observation of the eigenvalues of the model matrix. Model validation based on the comparison with NASA experimental results is described. The influence of operational and construction parameters on performance and stability issues is exposed. The results show that most parameters that are beneficial for machine power seem to induce irregular mechanical characteristics with load, suggesting that self-sustained oscillations could be difficult to maintain and control.

  16. Improving Power Density of Free-Piston Stirling Engines

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell H.; Prahl, Joseph; Loparo, Kenneth

    2016-01-01

    Analyses and experiments demonstrate the potential benefits of optimizing piston and displacer motion in a free piston Stirling Engine. Isothermal analysis shows the theoretical limits of power density improvement due to ideal motion in ideal Stirling engines. More realistic models based on nodal analysis show that ideal piston and displacer waveforms are not optimal, often producing less power than engines that use sinusoidal piston and displacer motion. Constrained optimization using nodal analysis predicts that Stirling engine power density can be increased by as much as 58 using optimized higher harmonic piston and displacer motion. An experiment is conducted in which an engine designed for sinusoidal motion is forced to operate with both second and third harmonics, resulting in a maximum piston power increase of 14. Analytical predictions are compared to experimental data showing close agreement with indirect thermodynamic power calculations, but poor agreement with direct electrical power measurements.

  17. Improving Power Density of Free-Piston Stirling Engines

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell H.; Prahl, Joseph M.; Loparo, Kenneth A.

    2016-01-01

    Analyses and experiments demonstrate the potential benefits of optimizing piston and displacer motion in a free-piston Stirling Engine. Isothermal analysis shows the theoretical limits of power density improvement due to ideal motion in ideal Stirling engines. More realistic models based on nodal analysis show that ideal piston and displacer waveforms are not optimal, often producing less power than engines that use sinusoidal piston and displacer motion. Constrained optimization using nodal analysis predicts that Stirling engine power density can be increased by as much as 58 percent using optimized higher harmonic piston and displacer motion. An experiment is conducted in which an engine designed for sinusoidal motion is forced to operate with both second and third harmonics, resulting in a piston power increase of as much as 14 percent. Analytical predictions are compared to experimental data and show close agreement with indirect thermodynamic power calculations, but poor agreement with direct electrical power measurements.

  18. Improving Free-Piston Stirling Engine Power Density

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell H.

    2016-01-01

    Analyses and experiments demonstrate the potential benefits of optimizing piston and displacer motion in a free piston Stirling Engine. Isothermal analysis shows the theoretical limits of power density improvement due to ideal motion in ideal Stirling engines. More realistic models based on nodal analysis show that ideal piston and displacer waveforms are not optimal, often producing less power than engines that use sinusoidal piston and displacer motion. Constrained optimization using nodal analysis predicts that Stirling engine power density can be increased by as much as 58% using optimized higher harmonic piston and displacer motion. An experiment is conducted in which an engine designed for sinusoidal motion is forced to operate with both second and third harmonics, resulting in a maximum piston power increase of 14%. Analytical predictions are compared to experimental data showing close agreement with indirect thermodynamic power calculations, but poor agreement with direct electrical power measurements.

  19. Free-piston regenerative hot gas hydraulic engine

    NASA Technical Reports Server (NTRS)

    Beremand, D. G. (Inventor)

    1980-01-01

    A displacer piston which is driven pneumatically by a high-pressure or low-pressure gas is included in a free-piston regenerative hydraulic engine. Actuation of the displacer piston circulates the working fluid through a heater, a regenerator and a cooler. The present invention includes an inertial mass such as a piston or a hydraulic fluid column to effectively store and supply energy during portions of the cycle. Power is transmitted from the working fluid to a hydraulic fluid across a diaphragm or lightweight piston to achieve a hydraulic power out-put. The displacer piston of the present invention may be driven pneumatically, hydraulically or electromagnetically. In addition, the displacer piston and the inertial mass of the present invention may be positioned on the same side of the diaphragm member or may be separated by the diaphragm member.

  20. Loss terms in free-piston Stirling engine models

    NASA Technical Reports Server (NTRS)

    Gordon, Lloyd B.

    1992-01-01

    Various models for free piston Stirling engines are reviewed. Initial models were developed primarily for design purposes and to predict operating parameters, especially efficiency. More recently, however, such models have been used to predict engine stability. Free piston Stirling engines have no kinematic constraints and stability may not only be sensitive to the load, but also to various nonlinear loss and spring constraints. The present understanding is reviewed of various loss mechanisms for free piston Stirling engines and how they have been incorporated into engine models is discussed.

  1. 13. View of disassembled steam engine showing cylinder, piston rod, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. View of disassembled steam engine showing cylinder, piston rod, parallel motion links and steam chest. - Hacienda Azucarera La Esperanza, Steam Engine & Mill, 2.65 Mi. N of PR Rt. 2 Bridge over Manati River, Manati, Manati Municipio, PR

  2. Structural design of Stirling engine with free pistons

    NASA Astrophysics Data System (ADS)

    Matusov, Jozef; Gavlas, Stanislav; Malcho, Milan

    2014-08-01

    Stirling engine is a device that converts thermal energy to mechanical work, which is mostly used to drive a generator of electricity. Advantage of Stirling engine is that it works with closed-cycle, where working medium is regularly cooled and heated, which acts on the working piston. This engine can be made in three modifications - alpha, beta, gamma. This paper discusses the design of the gamma Stirling engine with free pistons.

  3. Technology for reducing aircraft engine pollution

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Kempke, E. E., Jr.

    1975-01-01

    Programs have been initiated by NASA to develop and demonstrate advanced technology for reducing aircraft gas turbine and piston engine pollutant emissions. These programs encompass engines currently in use for a wide variety of aircraft from widebody-jets to general aviation. Emission goals for these programs are consistent with the established EPA standards. Full-scale engine demonstrations of the most promising pollutant reduction techniques are planned within the next three years. Preliminary tests of advanced technology gas turbine engine combustors indicate that significant reductions in all major pollutant emissions should be attainable in present generation aircraft engines without adverse effects on fuel consumption. Fundamental-type programs are yielding results which indicate that future generation gas turbine aircraft engines may be able to utilize extremely low pollutant emission combustion systems.

  4. PISTON

    SciTech Connect

    Sewell, Christopher Meyer

    2014-01-08

    This presentation was a part of the guest lecture series for graduate classes at the University of Oregon on many-core visualization. It discussed a practical introduction to high-level data parallelism using thrust and PISTON; presented an overview of PISTON and PINION; provided tutorial examples; additional details on research results.

  5. RE-1000 free-piston Stirling engine update

    NASA Technical Reports Server (NTRS)

    Schreiber, J.

    1985-01-01

    A free piston Stirling engine was tested. The tests performed over the past several years on the single cylinder engine were designed to investigate the dynamics of a free piston Stirling engine. The data are intended to be used primarily for computer code validation. The tests designed to investigate the sensitivity of the engine performance to variations in working space pressure, heater and cooler temperatures, regenerator porosity, power piston mass and displacer dynamics were completed. In addition, some data were recorded with alternate working fluids. A novel resonant balance system for the engine was also tested. Some preliminary test results of the tests performed are presented along with an outline of future tests to be run with the engine coupled to a hydraulic output unit. A description of the hydraulic output unit is given.

  6. Experimental Evaluation of the Free Piston Engine - Linear Alternator (FPLA)

    SciTech Connect

    Leick, Michael T.; Moses, Ronald W.

    2015-03-01

    This report describes the experimental evaluation of a prototype free piston engine - linear alternator (FPLA) system developed at Sandia National Laboratories. The opposed piston design wa developed to investigate its potential for use in hybrid electric vehicles (HEVs). The system is mechanically simple with two - stroke uniflow scavenging for gas exchange and timed port fuel injection for fuel delivery, i.e. no complex valving. Electrical power is extracted from piston motion through linear alternators wh ich also provide a means for passive piston synchronization through electromagnetic coupling. In an HEV application, this electrical power would be used to charge the batteries. The engine - alternator system was designed, assembled and operated over a 2 - year period at Sandia National Laboratories in Livermore, CA. This report primarily contains a description of the as - built system, modifications to the system to enable better performance, and experimental results from start - up, motoring, and hydrogen combus tion tests.

  7. Development free-piston Stirling test-bed engine

    NASA Astrophysics Data System (ADS)

    Dochat, G. R.; Vitale, N. G.; Moynihan, T. M.

    The free-piston Stirling Technology Demonstrator Engine (TDE) designed and instrumented to provide data to aid in understanding free-piston Stirling engine operation and performance, is described. It is noted that the system includes instrumentation to measure the internal thermodynamic operation and to permit calculation of system power flows. Near-term testing of the engine will assess three mechanisms for engine loss. It is pointed out that recent testing has demonstrated that the power and efficiency are strong functions of heater head temperature. A maximum power output of 1,800 watts and a thermodynamic efficiency of 30% have been demonstrated at 450 C and 40 bar.

  8. Aircraft Engine Emissions. [conference

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A conference on a aircraft engine emissions was held to present the results of recent and current work. Such diverse areas as components, controls, energy efficient engine designs, and noise and pollution reduction are discussed.

  9. The Demand for Single Engine Piston Aircraft,

    DTIC Science & Technology

    1987-08-01

    that may become certificated under a new proposed FAA regulation and the -I Pe Vore Sunbird . A proposed FAA regulation would create a new category of...exposure. Zenair, in Canada, where the laws discourage product liability suits, is not particularly concerned. The De Vore Sunbird is being built by De

  10. Energy efficient aircraft engines

    NASA Technical Reports Server (NTRS)

    Chamberlin, R.; Miller, B.

    1979-01-01

    The three engine programs that constitute the propulsion portion of NASA's Aircraft Energy Efficiency Program are described, their status indicated, and anticipated improvements in SFC discussed. The three engine programs are: (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 with cruise speeds to Mach 0.8. Unique propulsion system interactive ties to the airframe resulting from engine design features to reduce fuel consumption are discussed. Emphasis is placed on the advanced turboprop since it offers the largest potential fuel savings of the three propulsion programs and also has the strongest interactive ties to the airframe.

  11. Energy efficient aircraft engines

    NASA Technical Reports Server (NTRS)

    Chamberlin, R.; Miller, B.

    1979-01-01

    The three engine programs that constitute the propulsion portion of NASA's Aircraft Energy Efficiency Program are described, their status indicated, and anticipated improvements in SFC discussed. The three engine programs are (1) Engine Component Improvement--directed at current engines, (2) Energy Efficiency Engine directed at new turbofan engines, and (3) Advanced Turboprops--directed at technology for advanced turboprop--powered aircraft with cruise speeds to Mach 0.8. Unique propulsion system interactive ties to the airframe resulting from engine design features to reduce fuel consumption are discussed. Emphasis is placed on the advanced turboprop since it offers the largest potential fuel savings of the three propulsion programs and also has the strongest interactive ties to the airframe.

  12. Aircraft engines. II

    SciTech Connect

    Smith, M.G. Jr.

    1988-01-01

    An account is given of the design features and prospective performance gains of ultrahigh bypass subsonic propulsion configurations and various candidate supersonic commercial aircraft powerplants. The supersonic types, whose enhanced thermodynamic cycle efficiency is considered critical to the economic viability of a second-generation SST, are the variable-cycle engine, the variable stream control engine, the turbine-bypass engine, and the supersonic-throughflow fan. Also noted is the turboramjet concept, which will be applicable to hypersonic aircraft whose airframe structure materials can withstand the severe aerothermodynamic conditions of this flight regime.

  13. Aircraft engine pollution reduction

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1972-01-01

    The effect of engine operation on the types and levels of the major aircraft engine pollutants is described and the major factors governing the formation of these pollutants during the burning of hydrocarbon fuel are discussed. Methods which are being explored to reduce these pollutants are discussed and their application to several experimental research programs are pointed out. Results showing significant reductions in the levels of carbon monoxide, unburned hydrocarbons, and oxides of nitrogen obtained from experimental combustion research programs are presented and discussed to point out potential application to aircraft engines.

  14. Raising the efficiency of piston-drive helium expansion engines

    SciTech Connect

    Chernetskii, V.D.; Mironova, N.A.

    1986-07-01

    Operating tests of a cryogenic helium installation show that, at normal operating-mode parameters, the temperature of the gas flowing out through the gap between the piston and cylinder of a piston-drive expansion machine is much higher than its inlet temperature to the machine. The fact that preheated gas enters the expansion engine in line with a reverse current increases the temperature differnce between the direct and and reverse streams in the heat exchanger, thereby lowering the refrigeration capacity and the efficiency of the installation's operation as a whole. Shown, is a diagram of the DPG-4-24/0.2 piston-drive expansion engine, and figures of the warmup of helium flowing out of the expander cylinder vs. inlet temperature to the expander, and heat flow to the helium flowing out of the cylinder vs. temperature at the inlet to the expander. It is concluded that the design of the cylinder piston unit widely used is not an optimal design since gas circulation that develops from the reciprocating motion of the rod results in an additional refrigeration loss for the entire cryogenic helium installation.

  15. Instantaneous engine frictional torque, its components and piston assembly friction

    SciTech Connect

    Nichols, F.A. ); Henein, N.A. . Center for Automotive Research)

    1992-05-01

    The overall goal of this report is to document the work done to determine the instantaneous frictional torque of internal combustion engine by using a new approach known as (P-[omega]) method developed at Wayne State University. The emphasis has been to improve the accuracy of the method, and apply it to both diesel and gasoline engines under different operating conditions. Also work included an investigation to determine the effect of using advanced materials and techniques to coat the piston rings on the instantaneous engine frictional torque and the piston assembly friction. The errors in measuring the angular velocity, [omega], have been determined and found to be caused by variations in the divisions within one encoder, encoder-to-encoder variations, misalignment within the encoder itself and misalignment between the encoder and crankshaft. The errors in measuring the cylinder gas pressure, P, have been determined and found to be caused by transducer-to-transducer variations, zero drift, thermal stresses and lack of linearity. The ability of the (P-[omega]) method in determining the frictional torque of many engine components has been demonstrated. These components include valve train, fuel injection pump with and without fuel injection, and piston with and without different ring combinations. The emphasis in this part of the research program has been on the piston-ring assembly friction. The effects of load and other operating variables on IFT have been determined. The motoring test, which is widely used in industry to measure engine friction has been found to be inaccurate. The errors have been determined at different loads.

  16. The 300 H.P. Benz Aircraft Engine

    NASA Technical Reports Server (NTRS)

    Heller, A

    1921-01-01

    A description is given of the Benz 12-cylinder aircraft engine. The 300 H.P. engine, with the cylinders placed at an angle of 60 degrees not only realizes a long-cherished conception, but has received refinement in detail. It may be described as a perfect example of modern German aircraft engine construction. Here, a detailed description is given of the construction of this engine. Emphasis is placed on the design and construction of the cylinders, pistons, and connecting rods. Also discussed are engine fitting, lubrication, oil pumps, bearings, the oil tank, fuel pump, carburetors, and cooling system.

  17. 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.

  18. Integrated two-cylinder liquid piston Stirling engine

    SciTech Connect

    Yang, Ning; Rickard, Robert; Pluckter, Kevin; Sulchek, Todd

    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 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.

  19. Optics in aircraft engines

    NASA Astrophysics Data System (ADS)

    Vachon, James; Malhotra, Subhash

    The authors describe optical IR&D (independent research and development) programs designed to demonstrate and evaluate optical technologies for incorporation into next-generation military and commercial aircraft engines. Using a comprehensive demonstration program to validate this technology in an on-engine environment, problems encountered can be resolved early and risk can be minimized. In addition to specific activities related to the optics demonstration on the fighter engine, there are other optical programs underway, including a solenoid control system, a light off detection system, and an optical communication link. Research is also underway in simplifying opto-electronics and exploiting multiplexing to further reduce cost and weight.

  20. Aircraft Engine Systems

    NASA Technical Reports Server (NTRS)

    Veres, Joseph

    2001-01-01

    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.

  1. 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.

  2. NACA Investigation of Fuel Performance in Piston-Type Engines

    NASA Technical Reports Server (NTRS)

    Barnett, Henry C

    1951-01-01

    This report is a compilation of many of the pertinent research data acquired by the National Advisory Committee for Aeronautics on fuel performance in piston engines. The original data for this compilation are contained in many separate NACA reports which have in the present report been assembled in logical chapters that summarize the main conclusions of the various investigations. Complete details of each investigation are not included in this summary; however, such details may be found, in the original reports cited at the end of each chapter.

  3. Simulation of the instantaneous free piston Stirling engine-electrical load interaction

    SciTech Connect

    Mehdizadeh, N.S.; Stouffs, P.

    1998-07-01

    In this paper the authors consider a gamma type free piston engine (that is, a configuration with a power piston cylinder and a separate displacer cylinder) with the MARTINI configuration (that is, with a free piston but a kinematically driven displacer). In the modeled engine, the displacer is driven by an electrical motor and there are two symmetrical, free, power pistons. This configuration ensures a complete balancing of the engine. The free pistons bear the moving parts of the linear electric alternators. This engine may be considered for solar to electrical energy conversion for land or space applications, for instance. A dynamic simulation of this engine has been developed using a decoupled analysis. The motion equation of the free piston induces a strong coupling between the electrical load and the thermodynamics inside the free piston Stirling engine. From the thermodynamics point of view, the piston-displacer phase lag is an important parameter. It is shown that if the electrical circuit elements (R-L-C) are constants, the phase lag between the free pistons and displacer motions is far from the optimum. However this phase lag can be controlled by means of a variable electrical resistance. For both cases of stand-alone engine with an independent electrical load, or grid-connected engine, it is shown how one can in a very simple way multiply the net electrical power by a factor 4 to 10 and the efficiency by a factor 1.25 to 2 without any engine geometry modification.

  4. Exhaust emissions reduction for intermittent combustion aircraft engines

    NASA Technical Reports Server (NTRS)

    Rezy, B. J.; Stuckas, K. J.; Tucker, J. R.; Meyers, J. E.

    1982-01-01

    Three concepts which, to an aircraft piston engine, provide reductions in exhaust emissions of hydrocarbons and carbon monoxide while simultaneously improving fuel economy. The three chosen concepts, (1) an improved fuel injection system, (2) an improved cooling cylinder head, and (3) exhaust air injection, when combined, show a synergistic relationship in achieving these goals. In addition, the benefits of variable ignition timing were explored and both dynamometer and flight testing of the final engine configuration were accomplished.

  5. 21. VIEW TO NORTHWEST, ENGINE/PUMP HOUSE EXTENSION, HIGH PRESSURE PISTON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. VIEW TO NORTHWEST, ENGINE/PUMP HOUSE EXTENSION, HIGH PRESSURE PISTON OF STEAM ENGINE NO. 4; CONTROL PANEL MOUNTED ON THE ENGINE; FLOOR VALVES CONTROL THE STEAM. - Deer Island Pumping Station, Boston, Suffolk County, MA

  6. Free-piston stirling engine endurance test program

    NASA Technical Reports Server (NTRS)

    Dochat, G.; Rauch, J.; Antonelli, G.

    1983-01-01

    The Free-Piston Stirling Engine (FPSE) has the potential to be a long-lived, highly reliable, power conversion device attractive for many product applications such as space, residential, or remote-site power. The purpose of endurance testing the FPSE is to demonstrate its potential for long life. The endurance program was directed at obtaining 1000 operational hours under various test conditions: low power, full stroke, duty cycle, and stop/start. Critical performance parameters were measured to note any change and/or trend. Inspections were conducted to measure and compare critical seal/bearing clearance. The engine performed well throughout the program, completing the 1000 hours. Hardware inspection, including the critical clearances, showed no significant change in hardware or clearance dimensions. The performance parameters did not exhibit any increasing or decreasing trends. The test program confirms the potential for long-life FPSE applications. Additional testing is planned to increase the test hours to 10,000.

  7. Loss terms in free-piston Stirling-engine models. Final Technical Report

    SciTech Connect

    Gordon, L.B.

    1992-01-01

    Various models for free piston Stirling engines are reviewed. Initial models were developed primarily for design purposes and to predict operating parameters, especially efficiency. More recently, however, such models have been used to predict engine stability. Free piston Stirling engines have no kinematic constraints and stability may not only be sensitive to the load, but also to various nonlinear loss and spring constraints. The present understanding is reviewed of various loss mechanisms for free piston Stirling engines and how they have been incorporated into engine models is discussed.

  8. CFD Modeling of Free-Piston Stirling Engines

    NASA Technical Reports Server (NTRS)

    Ibrahim, Mounir B.; Zhang, Zhi-Guo; Tew, Roy C., Jr.; Gedeon, David; Simon, Terrence W.

    2001-01-01

    NASA Glenn Research Center (GRC) is funding Cleveland State University (CSU) to develop a reliable Computational Fluid Dynamics (CFD) code that can predict engine performance with the goal of significant improvements in accuracy when compared to one-dimensional (1-D) design code predictions. The funding also includes conducting code validation experiments at both the University of Minnesota (UMN) and CSU. In this paper a brief description of the work-in-progress is provided in the two areas (CFD and Experiments). Also, previous test results are compared with computational data obtained using (1) a 2-D CFD code obtained from Dr. Georg Scheuerer and further developed at CSU and (2) a multidimensional commercial code CFD-ACE+. The test data and computational results are for (1) a gas spring and (2) a single piston/cylinder with attached annular heat exchanger. The comparisons among the codes are discussed. The paper also discusses plans for conducting code validation experiments at CSU and UMN.

  9. Lightweight piston

    NASA Technical Reports Server (NTRS)

    Taylor, Allan H. (Inventor)

    1987-01-01

    A lightweight piston composed of carbon-carbon composites is presented. The use of carbon-carbon composites over conventional materials, such as aluminum, reduces piston weight and improves thermal efficiency of the internal combustion reciprocation engine. Due to the negligible coefficient of thermal expansion and unique strength at elevated temperatures of carbon-carbon, the piston-to-cylinder wall clearance is so small as to eliminate the necessity for piston rings. Use of the carbon-carbon composite 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.

  10. Modernizing the Opposed-Piston Engine for More Efficient Military Ground Vehicle Applications

    DTIC Science & Technology

    2012-08-01

    paper introduces the Achates Power opposed-piston engine, providing detailed, measured results of its power density, thermal efficiency and low heat ...efficiency and lack of cylinder heads, OP engines have lower heat rejection to coolant. Moreover, as a two-stroke engine, they have inherently high...markets, high thermal efficiency, high specific power and low heat rejection make the Achates Power opposed-piston engine ideally suited for military

  11. 5-kWe Free-piston Stirling Engine Convertor

    NASA Technical Reports Server (NTRS)

    Chapman, Peter A.; Vitale, Nicholas A.; Walter, Thomas J.

    2008-01-01

    The high reliability, long life, and efficient operation of Free-Piston Stirling Engines (FPSEs) make them an attractive power system to meet future space power requirements with less mass, better efficiency, and less total heat exchanger area than other power convertor options. FPSEs are also flexible in configuration as they can be coupled with many potential heat sources and various heat input systems, heat rejection systems, and power management and distribution systems. Development of a 5-kWe Stirling Convertor Assembly (SCA) is underway to demonstrate the viability of an FPSE for space power. The design is a scaled-down version of the successful 12.5-kWe Component Test Power Converter (CTPC) developed under NAS3-25463. The ultimate efficiency target is 25% overall convertor efficiency (electrical power out over heat in). For the single cylinder prototype now in development, cost and time constraints required use of economical and readily available materials (steel versus beryllium) and components (a commercially available linear alternator) and thus lower efficiency. The working gas is helium at 150 bar mean pressure. The design consists of a displacer suspended on internally pumped gas bearings and a power piston/alternator supported on flexures. Non-contacting clearance seals are used between internal volumes. Heat to and from the prototype convertor is done via pumped liquid loops passing through shell and tube heat exchangers. The preliminary and detail designs of the convertor, controller, and support systems (heating loop, cooling loop, and helium supply system) are complete and all hardware is on order. Assembly and test of the prototype at Foster- Miller is planned for early 2008, when work will focus on characterizing convertor dynamics and steady-state operation to determine maximum power output and system efficiency. The device will then be delivered to Auburn University where assessments will include start-up and shutdown characterization and

  12. On the identification of piston slap events in internal combustion engines using tribodynamic analysis

    NASA Astrophysics Data System (ADS)

    Dolatabadi, N.; Theodossiades, S.; Rothberg, S. J.

    2015-06-01

    Piston slap is a major source of vibration and noise in internal combustion engines. Therefore, better understanding of the conditions favouring piston slap can be beneficial for the reduction of engine Noise, Vibration and Harshness (NVH). Past research has attempted to determine the exact position of piston slap events during the engine cycle and correlate them to the engine block vibration response. Validated numerical/analytical models of the piston assembly can be very useful towards this aim, since extracting the relevant information from experimental measurements can be a tedious and complicated process. In the present work, a coupled simulation of piston dynamics and engine tribology (tribodynamics) has been performed using quasi-static and transient numerical codes. Thus, the inertia and reaction forces developed in the piston are calculated. The occurrence of piston slap events in the engine cycle is monitored by introducing six alternative concepts: (i) the quasi-static lateral force, (ii) the transient lateral force, (iii) the minimum film thickness occurrence, (iv) the maximum energy transfer, (v) the lubricant squeeze velocity and (vi) the piston-impact angular duration. The validation of the proposed methods is achieved using experimental measurements taken from a single cylinder petrol engine in laboratory conditions. The surface acceleration of the engine block is measured at the thrust- and anti-thrust side locations. The correlation between the theoretically predicted events and the measured acceleration signals has been satisfactory in determining piston slap incidents, using the aforementioned concepts. The results also exhibit good repeatability throughout the set of measurements obtained in terms of the number of events occurring and their locations during the engine cycle.

  13. Double bowl piston

    DOEpatents

    Meffert, Darrel Henry; Urven, Jr., Roger Leroy; Brown, Cory Andrew; Runge, Mark Harold

    2007-03-06

    A piston for an internal combustion engine is disclosed. The piston has a piston crown with a face having an interior annular edge. The piston also has first piston bowl recessed within the face of the piston crown. The first piston bowl has a bottom surface and an outer wall. A line extending from the interior annular edge of the face and tangent with the outer wall forms an interior angle greater than 90 degrees with the face of the piston. The piston also has a second piston bowl that is centrally located and has an upper edge located below a face of the piston crown.

  14. Alloy design for aircraft engines

    NASA Astrophysics Data System (ADS)

    Pollock, Tresa M.

    2016-08-01

    Metallic materials are fundamental to advanced aircraft engines. While perceived as mature, emerging computational, experimental and processing innovations are expanding the scope for discovery and implementation of new metallic materials for future generations of advanced propulsion systems.

  15. Adaptive individual-cylinder thermal state control using piston cooling for a GDCI engine

    DOEpatents

    Roth, Gregory T; Husted, Harry L; Sellnau, Mark C

    2015-04-07

    A system for a multi-cylinder compression ignition engine includes a plurality of nozzles, at least one nozzle per cylinder, with each nozzle configured to spray oil onto the bottom side of a piston of the engine to cool that piston. Independent control of the oil spray from the nozzles is provided on a cylinder-by-cylinder basis. A combustion parameter is determined for combustion in each cylinder of the engine, and control of the oil spray onto the piston in that cylinder is based on the value of the combustion parameter for combustion in that cylinder. A method for influencing combustion in a multi-cylinder engine, including determining a combustion parameter for combustion taking place in in a cylinder of the engine and controlling an oil spray targeted onto the bottom of a piston disposed in that cylinder is also presented.

  16. Overview of NASA Lewis Research Center free-piston Stirling engine activities

    SciTech Connect

    Slaby, J.G.

    1984-01-01

    An overview of the National Aeronautics and Space Administration (NASA) Lewis Research Center (LeRC) free-piston Stirling engine activities is presented. These include (1) a generic free-piston Stirling technology project being conducted to develop technologies generic to both space power and terrestrial heat pump applications in a cooperative, cost-shared effort with the Department of Energy (DOE)/Oak Ridge National Laboratory (ORNL); and (2) a free-piston Stirling space power technology feasibility demonstration project being conducted in support of the Defense Advanced Research Projects Agency (DARPA), DOE, NASA, SP-100 project. The generic technology effort includes extensive parametric testing of a 1 kW free-piston Stirling engine (RE-1000), development of a free-piston Stirling performance computer code, design and fabrication under contract of a hydraulic output modification for RE-1000 engine tests, and a 1000-hour endurance test, under contract, of a 3 kWe free-piston Stirling/alternator engine. The newly initiated space power technology feasibility demonstration effort addresses the capability of scaling a free-piston Stirling/alternator system to about 25 kWe; developing thermodynamic cycle efficiency greater than or equal to 70 percent of Carnot at temperature ratios in the order of 1.5 to 2.0; achieving a power conversion unit specific weight of 6 kg/kWe; operating with noncontacting gas bearings; and dynamically balancing the system. Planned engine and component design and test efforts are described.

  17. Input/output models for general aviation piston-prop aircraft fuel economy

    NASA Technical Reports Server (NTRS)

    Sweet, L. M.

    1982-01-01

    A fuel efficient cruise performance model for general aviation piston engine airplane was tested. The following equations were made: (1) for the standard atmosphere; (2) airframe-propeller-atmosphere cruise performance; and (3) naturally aspirated engine cruise performance. Adjustments are made to the compact cruise performance model as follows: corrected quantities, corrected performance plots, algebraic equations, maximize R with or without constraints, and appears suitable for airborne microprocessor implementation. The following hardwares are recommended: ignition timing regulator, fuel-air mass ration controller, microprocessor, sensors and displays.

  18. Aircraft and Engine Development Testing

    DTIC Science & Technology

    1986-09-01

    Control in Flight * Integrated Inlet- engine * Power/weight Exceeds Unity F-lll * Advanced Engines * Augmented Turbofan * High Turbine Temperature...residence times). Also, fabrication of a small scale "hot" engine with rotating components such as compressors and turbines with cooled blades , is...capabil- ities are essential to meet the needs of current and projected aircraft and engine programs. The required free jet nozzles should be capable of

  19. Durability, Performance, and Emission of Diesel Engines Using Carbon Fiber Piston and Liner

    NASA Technical Reports Server (NTRS)

    Afify, E. M.; Roberts, W. L.

    1999-01-01

    This report summarizes the research conducted by NC State University in investigating the durability, performance and emission of a carbon fiber piston and liner in our single cylinder research Diesel engine. Both the piston and liner were supplied to NC State University by NASA LaRC and manufactured by C-CAT under a separate contract to NASA LaRC. The carbon-carbon material used to manufacture the piston and liner has significantly lower thermal conductivity, coefficient of thermal expansion, and superior strength characteristics at elevated temperatures when compared to conventional piston materials such as aluminum. The results of the carbon-carbon fiber piston testing were compared to a baseline configuration, which used a conventional aluminum piston in a steel liner. The parameters measured were the brake specific fuel consumption, ignition delay, frictional horsepower, volumetric efficiency, and durability characteristics of the two pistons. Testing was performed using a naturally aspirated Labeco Direct Injection single cylinder diesel engine. Two test cases were performed over a range of loads and speeds. The fixed test condition between the aluminum and carbon-carbon piston configurations was the brake mean effective pressure. The measured data was the fuel consumption rate, volumetric efficiency, load, speed, cylinder pressure, needle lift, and exhaust gas temperature. The cylinder pressure, and fuel consumption, exhaust gas temperature, and needle lift were recorded using a National Instruments DAQ board and a PC. All test cases used Diesel no. 2 for fuel.

  20. The development and testing of ceramic components in piston engines. Final report

    SciTech Connect

    McEntire, B.J.; Willis, R.W.; Southam, R.E.

    1994-10-01

    Within the past 10--15 years, ceramic hardware has been fabricated and tested in a number of piston engine applications including valves, piston pins, roller followers, tappet shims, and other wear components. It has been shown that, with proper design and installation, ceramics improve performance, fuel economy, and wear and corrosion resistance. These results have been obtained using rig and road tests on both stock and race engines. Selected summaries of these tests are presented in this review paper.

  1. Component improvement of free-piston Stirling engine key technology for space power

    NASA Technical Reports Server (NTRS)

    Alger, Donald L.

    1988-01-01

    The successful performance of the 25 kW Space Power Demonstrator (SPD) engine during an extensive testing period has provided a baseline of free piston Stirling engine technology from which future space Stirling engines may evolve. Much of the success of the engine was due to the initial careful selection of engine materials, fabrication and joining processes, and inspection procedures. Resolution of the few SPD engine problem areas that did occur has resulted in the technological advancement of certain key free piston Stirling engine components. Derivation of two half-SPD, single piston engines from the axially opposed piston SPD engine, designated as Space Power Research (SPR) engines, has made possible the continued improvement of these engine components. The two SPR engines serve as test bed engines for testing of engine components. Some important fabrication and joining processes are reviewed. Also, some component deficiencies that were discovered during SPD engine testing are described and approaches that were taken to correct these deficiencies are discussed. Potential component design modifications, based upon the SPD and SPR engine testing, are also reported.

  2. Dynamically balanced, hydraulically driven compressor/pump apparatus for resonant free piston Stirling engines

    SciTech Connect

    Corey, John A.

    1984-05-29

    A compressor, pump, or alternator apparatus is designed for use with a resonant free piston Stirling engine so as to isolate apparatus fluid from the periodically pressurized working fluid of the Stirling engine. The apparatus housing has a first side closed by a power coupling flexible diaphragm (the engine working member) and a second side closed by a flexible diaphragm gas spring. A reciprocally movable piston is disposed in a transverse cylinder in the housing and moves substantially at right angles relative to the flexible diaphragms. An incompressible fluid fills the housing which is divided into two separate chambers by suitable ports. One chamber provides fluid coupling between the power diaphragm of the RFPSE and the piston and the second chamber provides fluid coupling between the gas spring diaphragm and the opposite side of the piston. The working members of a gas compressor, pump, or alternator are driven by the piston. Sealing and wearing parts of the apparatus are mounted at the external ends of the transverse cylinder in a double acting arrangement for accessibility. An annular counterweight is mounted externally of the reciprocally movable piston and is driven by incompressible fluid coupling in a direction opposite to the piston so as to damp out transverse vibrations.

  3. Cooling Air Inlet and Exit Geometries on Aircraft Engine Installations

    NASA Technical Reports Server (NTRS)

    Katz, Joseph; Corsiglia, Victor R.; Barlow, Philip R.

    1982-01-01

    A semispan wing and nacelle of a typical general aviation twin-engine aircraft was tested to evaluate the cooling capability and drag or several nacelle shapes; the nacelle shapes included cooling air inlet and exit variations. The tests were conducted in the Ames Research Center 40 x 80-ft Wind Tunnel. It was found that the cooling air inlet geometry of opposed piston engine installations has a major effect on inlet pressure recovery, but only a minor effect on drag. Exit location showed large effect on drag, especially for those locations on the sides of the nacelle where the suction characteristics were based on interaction with the wing surface pressures.

  4. Space Power Free-Piston Stirling Engine Scaling Study

    NASA Technical Reports Server (NTRS)

    Jones, D.

    1989-01-01

    The design feasibility study is documented of a single cylinder, free piston Stirling engine/linear alternator (FPSE/LA) power module generating 150 kW-electric (kW sub e), and the determination of the module's maximum feasible power level. The power module configuration was specified to be a single cylinder (single piston, single displacer) FPSE/LA, with tuning capacitors if required. The design requirements were as follows: (1) Maximum electrical power output; (2) Power module thermal efficiency equal to or greater than 20 percent at a specific mass of 5 to 8 kg/kW(sub e); (3) Heater wall temperature/cooler wall temperature = 1050 K/525 K; (4) Sodium heat-pipe heat transport system, pumped loop NaK (sodium-potassium eutectic mixture) rejection system; (5) Maximum power module vibration amplitude = 0.0038 cm; and (6) Design life = 7 years (60,000 hr). The results show that a single cylinder FPSE/LA is capable of meeting program goals and has attractive scaling attributes over the power range from 25 to 150 kW(sub e). Scaling beyond the 150 kW(sub e) power level, the power module efficiency falls and the power module specific mass reaches 10 kg/kW(sub e) at a power output of 500 kW(sub e). A discussion of scaling rules for the engine, alternator, and heat transport systems is presented, along with a detailed description of the conceptual design of a 150 kW(sub e) power module that meets the requirements. Included is a discussion of the design of a dynamic balance system. A parametric study of power module performance conducted over the power output range of 25 to 150 kW(sub e) for temperature ratios of 1.7, 2.0, 2.5, and 3.0 is presented and discussed. The results show that as the temperature ratio decreases, the efficiency falls and specific mass increases. At a temperature ratio of 1.7, the 150 kW(sub e) power module cannot satisfy both efficiency and specific mass goals. As the power level increases from 25 to 150 kW(sub e) at a fixed temperature ratio, power

  5. Magnetic bearings for free-piston Stirling engines

    NASA Technical Reports Server (NTRS)

    Curwen, P. W.; Fleming, D. P.; Rao, D. K.; Wilson, D. S.

    1992-01-01

    The feasibility and efficacy of applying magnetic bearings to free-piston Stirling-cycle power conversion machinery currently being developed for long-term space missions are assessed. The study was performed for a 50-kWe Reference Stirling Space Power Converter (RSSPC) which currently uses hydrostatic gas bearings to support the reciprocating displacer and power piston assemblies. Active magnetic bearings of the attractive electromagnetic type are feasible for the RSSPC power piston. Magnetic support of the displacer assembly would require unacceptable changes to the design of the current RSSPC. However, magnetic suspension of both displacer and power piston is feasible for a relative-displacer version of the RSSPC. Magnetic suspension of the RSSPC power piston can potentially increase overall efficiency by 0.5 to 1 percent (0.1 to 0.3 efficiency points). Magnetic bearings will also overcome several operational concerns associated with hydrostatic gas bearing systems. These advantages, however, are accompanied by a 5 percent increase in specific mass of the RSSPC.

  6. Test Method Designed to Evaluate Cylinder Liner-Piston Ring Coatings for Advanced Heat Engines

    NASA Technical Reports Server (NTRS)

    Radil, Kevin C.

    1997-01-01

    Research on advanced heat engine concepts, such as the low-heat-rejection engine, have shown the potential for increased thermal efficiency, reduced emissions, lighter weight, simpler design, and longer life in comparison to current diesel engine designs. A major obstacle in the development of a functional advanced heat engine is overcoming the problems caused by the high combustion temperatures at the piston ring/cylinder liner interface, specifically at top ring reversal (TRR). Therefore, advanced cylinder liner and piston ring materials are needed that can survive under these extreme conditions. To address this need, researchers at the NASA Lewis Research Center have designed a tribological test method to help evaluate candidate piston ring and cylinder liner materials for advanced diesel engines.

  7. Mechanical and thermal analysis of the internal combustion engine piston using Ansys

    NASA Astrophysics Data System (ADS)

    Cioată, V. G.; Kiss, I.; Alexa, V.; Raţiu, S. A.

    2017-01-01

    The piston is one of the most important components of the internal combustion engine. Piston fail mainly due to mechanical stresses and thermal stresses. In this paper is determined by using the finite element method, stress and displacement distribution due the flue gas pressure and temperature, separately and combined. The FEA is performed by CAD and CAE software. The results are compared with those obtained by the analytical method and conclusions have been drawn.

  8. Control scheme for power modulation of a free piston Stirling engine

    DOEpatents

    Dhar, Manmohan

    1989-01-01

    The present invention relates to a control scheme for power modulation of a free-piston Stirling engine-linear alternator power generator system. The present invention includes connecting an autotransformer in series with a tuning capacitance between a linear alternator and a utility grid to maintain a constant displacement to piston stroke ratio and their relative phase angle over a wide range of operating conditions.

  9. Microphone Boom for Aircraft-Engine Monitoring

    NASA Technical Reports Server (NTRS)

    Cohn, R.; Economu, M.; Albrecht, W.

    1986-01-01

    Microphone for measuring aircraft engine noise mounted on lengthwise boom supported away from fuselage and engine. This configuration minimizes boundary-layer effects and pressure doubling that is present if microphone were mounted in aircraft fuselage.

  10. Fretting in aircraft turbine engines

    NASA Technical Reports Server (NTRS)

    Johnson, R. L.; Bill, R. C.

    1974-01-01

    The problem of fretting in aircraft turbine engines is discussed. Critical fretting can occur on fan, compressor, and turbine blade mountings, as well as on splines, rolling element bearing races, and secondary sealing elements of face type seals. Structural fatigue failures have been shown to occur at fretted areas on component parts. Methods used by designers to reduce the effects of fretting are given.

  11. Testing and performance characteristics of a 1-kW free piston Stirling engine

    NASA Technical Reports Server (NTRS)

    Schreiber, J.

    1983-01-01

    A 1 kW single cylinder free piston Stirling engine, configured as a research engine, was tested with helium working gas. The engine features a posted displacer and dashpot load. The test results show the engine power output and efficiency to be lower than those observed during acceptance tests by the manufacturer. Engine tests results are presented for operation at the two heater head temperatures and with two regenerator porosities, along with flow test results for the heat exchangers.

  12. Validation of thermodynamic and mechanical models of free piston Stirling engines

    NASA Astrophysics Data System (ADS)

    Carlini, M.; Cichy, M.; Mancini, M.

    1985-12-01

    Two distinctive physical-mathematical models for a free piston Stirling engine have been carried out, the thermodynamic and the dynamic ones, which are linked together by the outputs of the first becoming the inputs of the second. The paper then deals with the results reached by the authors on a test bench constructed ad hoc for a Beale free-piston Stirling engine of low power. The before mentioned models have been also validated by means of a comparison with the results of tests effected on the Stirling Beale engine.

  13. Investigation into piston-slap-induced vibration for engine condition simulation and monitoring

    NASA Astrophysics Data System (ADS)

    Geng, Z.; Chen, J.

    2005-04-01

    Piston slap is a common impact phenomenon existing in the reciprocating engine. It is also a major cause of the complex transient vibration response related to the impact excitation inside the engine. In order to correlate the piston-slap impact with the slap-induced vibration and consequently find out an effective approach for the engine dynamic behaviour simulation and working condition monitoring, an in-depth investigation from theoretical modelling to experimental verification is made in this paper. Firstly, the piston-slap phenomenon inside the reciprocating engine is briefly discussed from the viewpoint of engine mechanics. Based upon this, a nonlinear model is developed to simulate the slap-induced vibration response. Using numerical integration procedure, the slap-induced vibration response and its correlation with the inner-cylinder piston-slap impact are reasonably evaluated. Guided by the simulating results and, by introducing a fast wavelet-packet decomposition and reconstruction algorithm, a specially designed experiment is made to practically measure and extract the slap-induced impact message inside the 6190Z LC diesel engine. Comparison between the simulation and practically measured and reconstructed engine vibration signals verifies the effectiveness and practicality of this approach for more detailed academic research and engineering application.

  14. Lightweight aircraft engines, the potential and problems for use of automotive fuels

    NASA Technical Reports Server (NTRS)

    Patterson, D. J.

    1983-01-01

    A comprehensive data research and analysis for evaluating the use of automotive fuels as a substitute for aviation grade fuel by piston-type general aviation aircraft engines is presented. Historically known problems and potential problems with fuels were reviewed for possible impact relative to application to an aircraft operational environment. This report reviews areas such as: fuel specification requirements, combustion knock, preignition, vapor lock, spark plug fouling, additives for fuel and oil, and storage stability.

  15. Development of free-piston Stirling engine performance and optimization codes based on Martini simulation technique

    NASA Technical Reports Server (NTRS)

    Martini, William R.

    1989-01-01

    A FORTRAN computer code is described that could be used to design and optimize a free-displacer, free-piston Stirling engine similar to the RE-1000 engine made by Sunpower. The code contains options for specifying displacer and power piston motion or for allowing these motions to be calculated by a force balance. The engine load may be a dashpot, inertial compressor, hydraulic pump or linear alternator. Cycle analysis may be done by isothermal analysis or adiabatic analysis. Adiabatic analysis may be done using the Martini moving gas node analysis or the Rios second-order Runge-Kutta analysis. Flow loss and heat loss equations are included. Graphical display of engine motions and pressures and temperatures are included. Programming for optimizing up to 15 independent dimensions is included. Sample performance results are shown for both specified and unconstrained piston motions; these results are shown as generated by each of the two Martini analyses. Two sample optimization searches are shown using specified piston motion isothermal analysis. One is for three adjustable input and one is for four. Also, two optimization searches for calculated piston motion are presented for three and for four adjustable inputs. The effect of leakage is evaluated. Suggestions for further work are given.

  16. Overview of NASA Lewis Research Center free-piston Stirling engine activities

    NASA Technical Reports Server (NTRS)

    Slaby, J. G.

    1984-01-01

    A generic free-piston Stirling technology project is being conducted to develop technologies generic to both space power and terrestrial heat pump applications in a cooperative, cost-shared effort. The generic technology effort includes extensive parametric testing of a 1 kW free-piston Stirling engine (RE-1000), development of a free-piston Stirling performance computer code, design and fabrication under contract of a hydraulic output modification for RE-1000 engine tests, and a 1000-hour endurance test, under contract, of a 3 kWe free-piston Stirling/alternator engine. A newly initiated space power technology feasibility demonstration effort addresses the capability of scaling a free-piston Stirling/alternator system to about 25 kWe; developing thermodynamic cycle efficiency or equal to 70 percent of Carnot at temperature ratios in the order of 1.5 to 2.0; achieving a power conversion unit specific weight of 6 kg/kWe; operating with noncontacting gas bearings; and dynamically balancing the system. Planned engine and component design and test efforts are described.

  17. Exhaust emission reduction for intermittent combustion aircraft engines

    NASA Technical Reports Server (NTRS)

    Moffett, R. N.

    1979-01-01

    Three concepts for optimizing the performance, increasing the fuel economy, and reducing exhaust emission of the piston aircraft engine were investigated. High energy-multiple spark discharge and spark plug tip penetration, ultrasonic fuel vaporization, and variable valve timing were evaluated individually. Ultrasonic fuel vaporization did not demonstrate sufficient improvement in distribution to offset the performance loss caused by the additional manifold restriction. High energy ignition and revised spark plug tip location provided no change in performance or emissions. Variable valve timing provided some performance benefit; however, even greater performance improvement was obtained through induction system tuning which could be accomplished with far less complexity.

  18. Experimental Investigation of Piston Heat Transfer in a Light Duty Engine

    DTIC Science & Technology

    2014-01-01

    Experimental Investigation of Piston Heat Transfer in a Light Duty Engine Eric Gingrich Experimental Setup Single- Cylinder Engine...Laboratory Experiments were conducted in a light-duty single- cylinder engine based on the General Motors/Fiat JTD 1.9L four- cylinder diesel engine. A stock...four cylinder head was installed atop a single cylinder block. Valves for cylinder #2 were activated by the dual overhead cams. The valvetrain for

  19. Stochastic stability assessment of a semi-free piston engine generator concept

    NASA Astrophysics Data System (ADS)

    Kigezi, T. N.; Gonzalez Anaya, J. A.; Dunne, J. F.

    2016-09-01

    Small engines, as power generators with low-noise and vibration characteristics, are needed in two niche application areas: as electric vehicle range extenders and as domestic micro Combined Heat and Power systems. A recent semi-free piston design known as the AMOCATIC generator fully meets this requirement. The engine potentially allows for high energy conversion efficiencies at resonance derived from having a mass and spring assembly. As with free-piston engines in general, stability and control of piston motion has been cited as the prime challenge limiting the technology's widespread application. Using physical principles, we derive in this paper two important results: an energy balance criterion and a related general stability criterion for a semi-free piston engine. Control is achieved by systematically designing a Proportional Integral (PI) controller using a control-oriented engine model for which a specific stability condition is stated. All results are presented in closed form throughout the paper. Simulation results under stochastic pressure conditions show that the proposed energy balance, stability criterion, and PI controller, operate as predicted to yield stable engine operation at fixed compression ratio.

  20. The effect of thermal barrier coated piston crown on engine characteristics

    SciTech Connect

    Chan, S.H.; Khor, K.A.

    2000-02-01

    While there have been numerous research papers in recent years describing the theoretical benefits obtained from the use of ceramic components in reciprocating engines, the amount of literature that describes practical results is very limited. Although successes have been reported and ceramic components are now in service in production engines, mainly for reduced in-cylinder heat rejection, many researchers have experienced failures or a drop in engine performance. This article presents the work completed on a low heat rejection engine. Extensive experiments were conducted on a three-cylinder SI Daihatsu engine with piston crowns coated with a layer of ceramic, which consisted of yttria-stabilized zirconia (YSZ). Measurement and comparison of engine performance, in particular fuel consumption, were made before and after the application of YSZ coatings deposited onto the piston crowns. The details of the cylinder pressures during the combustion process were also investigated.

  1. Four-piston double-duct liquid metal MHD engine and AC generator

    SciTech Connect

    Haaland, C.M.

    1995-12-31

    Operating principles, features and applications of the Liquid Metal (LM) engine are presented. This engine combines a free-piston internal combustion engine with an MHD AC power generator. Liquid metal (LM) oscillates back-and-forth in two separate channels, driven by free pistons coupled magnetically to pistons driven by internal combustion. One of the principal breakthroughs is the concept of using double ducts in a Hartmann configuration for MHD production of alternating current. The LM flows in opposing directions in the two adjacent Hartmann ducts, thus eliminating magnetic-induced instabilities, eliminating vibration, and providing an ideal setup for attaching an output transformer on one side provide to provide useful ranges of current and voltage. Because LM is used, the length of the piston stroke can be easily varied over a large range, thus making possible an engine that, changes size, according to variation in output load requirements. Increasing the stroke length results in increased compression ratio, which requires computer controlled modification of the fuel injection mixture. Higher fuel efficiencies will result, whether the engine is idling or operating at maximum power. Because of viscous dissipation losses in the LM, this engine will be more efficient for larger engines. Applications include any power generation where variable load is required, such as stationary electric generators for remote towns and cities, temporary military encampments, and mobile primary power generators for off-road and on-road automotive equipment, including caterpillars, cars, military vehicles, trucks, and trains. The advantages for automotive propulsion will be described in comparisons with current and developmental vehicles using internal combustion engines. Because the LM-engine generates electricity, an LM-engine vehicle is readily adaptable to hybrid concepts. An R&D program will be outlined for bringing the concept of the LM engine to commercial application.

  2. Piston Bowl Optimization for RCCI Combustion in a Light-Duty Multi-Cylinder Engine

    SciTech Connect

    Hanson, Reed M; Curran, Scott; Wagner, Robert M; Reitz, Rolf; Kokjohn, Sage

    2012-01-01

    Reactivity Controlled Compression Ignition (RCCI) is an engine combustion strategy that that produces low NO{sub x} and PM emissions with high thermal efficiency. Previous RCCI research has been investigated in single-cylinder heavy-duty engines. The current study investigates RCCI operation in a light-duty multi-cylinder engine at 3 operating points. These operating points were chosen to cover a range of conditions seen in the US EPA light-duty FTP test. The operating points were chosen by the Ad Hoc working group to simulate operation in the FTP test. The fueling strategy for the engine experiments consisted of in-cylinder fuel blending using port fuel-injection (PFI) of gasoline and early-cycle, direct-injection (DI) of diesel fuel. At these 3 points, the stock engine configuration is compared to operation with both the original equipment manufacturer (OEM) and custom machined pistons designed for RCCI operation. The pistons were designed with assistance from the KIVA 3V computational fluid dynamics (CFD) code. By using a genetic algorithm optimization, in conjunction with KIVA, the piston bowl profile was optimized for dedicated RCCI operation to reduce unburned fuel emissions and piston bowl surface area. By reducing these parameters, the thermal efficiency of the engine was improved while maintaining low NOx and PM emissions. Results show that with the new piston bowl profile and an optimized injection schedule, RCCI brake thermal efficiency was increased from 37%, with the stock EURO IV configuration, to 40% at the 2,600 rev/min, 6.9 bar BMEP condition, and NOx and PM emissions targets were met without the need for exhaust after-treatment.

  3. 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

    ... 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 Coast Guard, aircraft, aircraft engines, and ground flight simulators, including...

  4. 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 Coast Guard, aircraft, aircraft engines, and ground flight simulators, including...

  5. 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

    ... 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 Coast Guard, aircraft, aircraft engines, and ground flight simulators, including...

  6. 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 Coast Guard, aircraft, aircraft engines, and ground flight simulators, including...

  7. 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

    ... 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 Coast Guard, aircraft, aircraft engines, and ground flight simulators, including...

  8. 75 FR 32315 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ..., 912 F, and 912 S series engines. Versions of the 912 F series and 912 S series engines are type... not have an engine type certificate; instead, the engine is part of the aircraft type design. You may... Equipped With Rotax Aircraft Engines 912 A Series Engines AGENCY: Federal Aviation Administration...

  9. Nitrited-Steel Piston Rings for Engines of High Specific Power

    NASA Technical Reports Server (NTRS)

    Collins, John H; Bisson, Edmond E; Schmiedlin, Ralph F

    1945-01-01

    Stability and control characteristics determined from tests in the Langley 19-foot pressure tunnel of a 0.2375-scale model of the Douglas XA-26 airplane are compared with those measured in flight tests of a Douglas A-26b airplane. Several designs of nitrided-steel piston rings were performance-tested under variable conditions of output. The necessity of good surface finish and conformity of the ring to the bore was indicated in the preliminary tests. Nitrided-steel rings of the same dimensions as cast-iron rings operating on the original piston were unsatisfactory, and the final design was a lighter, rectangular, thin-face-width ring used on a piston having a maximum cross-head area and a revised skirt shape. Results were obtained from single-cylinder and multicylinder engine runs.

  10. Overview of the 1985 NASA Lewis Research Center SP-100 free-piston Stirling engine activities

    NASA Technical Reports Server (NTRS)

    Slaby, J.

    1985-01-01

    This effort is keyed on the design, fabrication, assembly, and testing of a 25 kWe Stirling space-power technology-feasibility demonstrator engine. Another facet of the SP-100 project covers the status of a 9000-hr endurance test conducted on a 2 kWe free-piston Stirling/linear alternator system employing hydrostatic gas bearings. Dynamic balancing of the RE-1000 engine (a 1 kWe free-piston Stirling engine) using a passive dynamic absorber will be discussed along with the results of a parametric study showing the relationships of Stirling power converter specific weight and efficiency as functions of Stirling engine heater to cooler temperature ratio. Planned tests will be described covering a hydrodynamic gas bearing concept for potential SP-100 application.

  11. Comparative survey of dynamic analyses of free-piston stirling engines

    SciTech Connect

    Kankam, M.D.; Rauch, J.S.

    1994-09-01

    This paper compares reported dynamic analyses for evaluating the steady-state response and stability of free-piston Stirling engine (FPSE) systems. Various analytical approaches are discussed to provide guidance on their salient features. Recommendations are made in the recommendations remarks for an approach which captures most of the inherent properties of the engine. Such an approach has the potential for yielding results which will closely match practical FPSE-load systems.

  12. Comparative survey of dynamic analyses of free-piston Stirling engines

    NASA Technical Reports Server (NTRS)

    Kankam, M. David; Rauch, Jeffrey S.

    1991-01-01

    Reported dynamics analyses for evaluating the steady-state response and stability of free-piston Stirling engine (FPSE) systems are compared. Various analytical approaches are discussed to provide guidance on their salient features. Recommendations are made in the recommendations remarks for an approach which captures most of the inherent properties of the engine. Such an approach has the potential for yielding results which will closely match practical FPSE-load systems.

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

    SciTech Connect

    Slaby, J.G.

    1987-01-01

    An overview is presented of the National Aeronautics and Space Administration (NASA) Lewis Research Center (LeRC) free-piston Stirling engine activities directed toward space-power application. One of the major elements of the program is the development of advanced power conversion of which the Stirling cycle is a viable candidate. Under this program the status of the 25 kWe opposed-piston Space Power Demonstrator Engine (SPDE) is presented. Technology work is also conducted on heat-exchanger concepts, both design and fabrication, to minimize the number of joints as well as to enhance the heat transfer in the heater. Design parameters and conceptual design features are also presented for a 25 kWe, single-cylinder free-piston Stirling space-power converter. Projections are made for future space-power requirements over the next few decades along with a recommendation to consider the use of dynamic power-conversion systems - either solar or nuclear. A description of a study to investigate the feasibility of scaling a single-cylinder free-piston Stirling space-power module to the 150 kWe power range is presented.

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

    NASA Technical Reports Server (NTRS)

    Slaby, Jack G.

    1987-01-01

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

  15. The Development of a Control System for a 5 Kilowatt Free Piston Stirling Engine Convertor

    NASA Technical Reports Server (NTRS)

    Kirby, Raymond L.; Vitale, Nick

    2008-01-01

    The new NASA Vision for Exploration, announced by President Bush in January 2004, proposes an ambitious program that plans to return astronauts to the moon by the 2018 time frame. A recent NASA study entitled "Affordable Fission Surface Power Study" recommended a 40 kWe, 900 K, NaK-cooled, Stirling convertors for 2020 launch. Use of two of the nominal 5 kW convertors allows the system to be dynamically balanced. A group of four dual-convertor combinations that would yield 40 kWe can be tested to validate the viability of Stirling technology for space fission surface power systems. The work described in this paper deals specifically with the control system for the 5 kW convertor described in the preceding paragraph. This control system is responsible for maintaining piston stroke to a setpoint in the presence of various disturbances including electrical load variations. Pulse starting of the Free Piston Stirling Engine (FPSE) convertor is also an inherent part of such a control system. Finally, the ability to throttle the engine to match the required output power is discussed in terms of setpoint control. Several novel ideas have been incorporated into the piston stroke control strategy that will engender a stable response to disturbances in the presence of midpoint drift while providing useful data regarding the position of both the power piston and displacer.

  16. Overview of the 1985 NASA Lewis Research Center SP-100 free-piston Stirling engine activities

    SciTech Connect

    Slaby, J.G.

    1985-01-01

    An overview of the 1985 (NASA) Lewis Research Center free-piston Stirling engine activities in support of the SP-100 Program is presented. The SP-100 program is being conducted in support of the Department of Advanced Research Projects Agency (DARPA) and the Department of Energy (DOE), and NASA. This effort is keyed on the design, fabrication, assembly, and testing of a 25 kW(e) Stirling space-power technology-feasibility demonstrator engine. Another facet of the SP-100 project covers the status of a 9000-h goal endurance test conducted on a 2 kW(e) free-piston Stirling/linear alternator system employing hydrostatic gas bearings. Dynamic balancing of the RE-1000 engine (a 1 kW(e) free-piston Stirling engine) using a passive dynamic absorber is discussed, along with the results of a parametric study showing the relationships of Stirling power converter specific weight and efficiency as functions of Stirling engine heater to cooler temperature ratio. Planned tests are described covering a hydrodynamic gas bearing concept for potential SP-100 application.

  17. RE-1000 free-piston Stirling engine sensitivity test results. Final report

    SciTech Connect

    Schreiber, J.G.; Geng, S.M.; Lorenz, G.V.

    1986-10-01

    The NASA Lewis Research Center has been testing a 1 kW (1.33 hp) free-piston Stirling engine at the NASA Lewis test facilities. The tests performed over the past several years have been on a single cylinder machine known as the RE-1000. The data recorded were to aid in the investigation of the dynamics and thermodynamics of the free-piston Stirling engine. The data are intended to be used primarily for computer code validation. NASA reports TM-82999, TM-83407, and TM-87126 give initial results of the engine tests. The tests were designed to investigate the sensitivity of the engine performance to variations on the mean pressure of the working space, the working fluid used, heater and cooler temperatures, regenerator porosity, power piston mass and displacer dynamics. These tests have now been completed at NASA Lewis. This report presents some of the detailed data collected in the sensitivity tests. In all, 781 data points were recorded. A complete description of the engine and test facility is given. Many of the data can be found in tabular form, while a microfiche containing all of the data points can be requested from NASA Lewis.

  18. Instantaneous engine frictional torque, its components and piston assembly friction. Final report

    SciTech Connect

    Nichols, F.A.; Henein, N.A.

    1992-05-01

    The overall goal of this report is to document the work done to determine the instantaneous frictional torque of internal combustion engine by using a new approach known as (P-{omega}) method developed at Wayne State University. The emphasis has been to improve the accuracy of the method, and apply it to both diesel and gasoline engines under different operating conditions. Also work included an investigation to determine the effect of using advanced materials and techniques to coat the piston rings on the instantaneous engine frictional torque and the piston assembly friction. The errors in measuring the angular velocity, {omega}, have been determined and found to be caused by variations in the divisions within one encoder, encoder-to-encoder variations, misalignment within the encoder itself and misalignment between the encoder and crankshaft. The errors in measuring the cylinder gas pressure, P, have been determined and found to be caused by transducer-to-transducer variations, zero drift, thermal stresses and lack of linearity. The ability of the (P-{omega}) method in determining the frictional torque of many engine components has been demonstrated. These components include valve train, fuel injection pump with and without fuel injection, and piston with and without different ring combinations. The emphasis in this part of the research program has been on the piston-ring assembly friction. The effects of load and other operating variables on IFT have been determined. The motoring test, which is widely used in industry to measure engine friction has been found to be inaccurate. The errors have been determined at different loads.

  19. Lightweight diesel aircraft engines for general aviation

    NASA Technical Reports Server (NTRS)

    Berenyi, S. G.; Brouwers, A. P.

    1980-01-01

    A methodical design study was conducted to arrive at new diesel engine configurations and applicable advanced technologies. Two engines are discussed and the description of each engine includes concept drawings. A performance analysis, stress and weight prediction, and a cost study were also conducted. This information was then applied to two airplane concepts, a six-place twin and a four-place single engine aircraft. The aircraft study consisted of installation drawings, computer generated performance data, aircraft operating costs and drawings of the resulting airplanes. The performance data shows a vast improvement over current gasoline-powered aircraft. At the completion of this basic study, the program was expanded to evaluate a third engine configuration. This third engine incorporates the best features of the original two, and its design is currently in progress. Preliminary information on this engine is presented.

  20. Free-piston Stirling Engine system considerations for various space power applications

    NASA Astrophysics Data System (ADS)

    Dochat, George R.; Dhar, Manmohan

    Free-Piston Stirling Engines (FPSE) have the potential to provide high reliability, long life, and efficient operation. Therefore, they are excellent candidates for the dynamic power conversion module of a space-based, power-generating system. FPSE can be coupled with many potential heat sources (radioisotope, solar, or nuclear reactor), various heat input systems (pumped loop, heat pipe), heat rejection (pumped loop or heat pipe), and various power management and distribution systems (ac, dc, high or low voltage, and fixed or variable load). This paper reviews potential space missions that can be met using free-piston Stirling engines and discusses options of various system integration approaches. This paper briefly outlines the program and recent progress.

  1. Development of Gas-Lubricated Pistons for Heavy Duty Diesel Engine Technology Program

    NASA Technical Reports Server (NTRS)

    Shapiro, W.

    1984-01-01

    Static testing of a segmented, gas-lubricated, piston-ring was accomplished. The ring utilizes high-pressure gas generated during the diesel cycle to energize a hydrostatic gas film between the piston and cylinder liner. The configuration was deficient in overall performance, because all segments of a ring set failed to form a fluid-film simultaneously, when exposed to internal preload. The difficulty was traced to the moment balance required to prevent the segments from overturning and contacting the cylinder walls. Some individual sectors formed a film and performed well in every respect including load capability to 6,000 N. These results produce optimism as to the ultimate feasibility of hydrostatic, gas-lubricated piston rings. In addition to test results, the principles of operation, and theoretical developments are presented. Breathable liner concepts are suggested for future consideration. In these configurations, solid hydrostatic pistons are coupled with flexible liners that elastically deform to form a gas-film under hydrostatic pressurization. Breathable liners afford the mechanical simplicity required for mass produced engines, and initial examination indicates satisfactory operation.

  2. Design of heat exchanger for Ericsson-Brayton piston engine.

    PubMed

    Durcansky, Peter; Papucik, Stefan; Jandacka, Jozef; Holubcik, Michal; Nosek, Radovan

    2014-01-01

    Combined power generation or cogeneration is a highly effective technology that produces heat and electricity in one device more efficiently than separate production. Overall effectiveness is growing by use of combined technologies of energy extraction, taking heat from flue gases and coolants of machines. Another problem is the dependence of such devices on fossil fuels as fuel. For the combustion turbine is mostly used as fuel natural gas, kerosene and as fuel for heating power plants is mostly used coal. It is therefore necessary to seek for compensation today, which confirms the assumption in the future. At first glance, the obvious efforts are to restrict the use of largely oil and change the type of energy used in transport. Another significant change is the increase in renewable energy--energy that is produced from renewable sources. Among machines gaining energy by unconventional way belong mainly the steam engine, Stirling engine, and Ericsson engine. In these machines, the energy is obtained by external combustion and engine performs work in a medium that receives and transmits energy from combustion or flue gases indirectly. The paper deals with the principle of hot-air engines, and their use in combined heat and electricity production from biomass and with heat exchangers as primary energy transforming element.

  3. Design of Heat Exchanger for Ericsson-Brayton Piston Engine

    PubMed Central

    Durcansky, Peter; Papucik, Stefan; Jandacka, Jozef

    2014-01-01

    Combined power generation or cogeneration is a highly effective technology that produces heat and electricity in one device more efficiently than separate production. Overall effectiveness is growing by use of combined technologies of energy extraction, taking heat from flue gases and coolants of machines. Another problem is the dependence of such devices on fossil fuels as fuel. For the combustion turbine is mostly used as fuel natural gas, kerosene and as fuel for heating power plants is mostly used coal. It is therefore necessary to seek for compensation today, which confirms the assumption in the future. At first glance, the obvious efforts are to restrict the use of largely oil and change the type of energy used in transport. Another significant change is the increase in renewable energy—energy that is produced from renewable sources. Among machines gaining energy by unconventional way belong mainly the steam engine, Stirling engine, and Ericsson engine. In these machines, the energy is obtained by external combustion and engine performs work in a medium that receives and transmits energy from combustion or flue gases indirectly. The paper deals with the principle of hot-air engines, and their use in combined heat and electricity production from biomass and with heat exchangers as primary energy transforming element. PMID:24977174

  4. Reciprocating balance weight mechanism for a piston type internal combustion engine

    SciTech Connect

    Nivi, H.; Field, N.L. III

    1987-08-25

    A balancing mechanism is described for reducing the vibration of a piston type internal combustion engine having a crankshaft and a camshaft, the balancing mechanisms comprising one or more reciprocating balance weights, with each weight comprising an elongate body having a cam follower mounted at either end and with each weight being driven by two rotating cams with at least one of the cams being driven by either the crankshaft or the camshaft.

  5. Evaluation of a Hybrid-Piston Pulsed Detonation Engine

    DTIC Science & Technology

    2002-01-01

    Stutrud (AFRL/PRTS) and Jason Parker (ISSI) for their computer programs used to collect and analyze the data, and Mike Bruggeman (AFRL/PROE)for his...Performance Results for Pulsed Detonation Engine Applications". in 39th AIAA Aerospace Sciences Meeting and Exhibit. Reno, NV (2001). 3. Heywood

  6. Fluid dynamic modeling of a free piston engine with labyrinth seals

    NASA Astrophysics Data System (ADS)

    Larjola, Jaakko; Honkatukia, Juha; Sallinen, Petri; Backman, Jari

    2010-04-01

    Preliminary design and simulation of a free piston engine suitable for small-scale energy production in distributed energy systems is presented in this paper. The properties, particularly the properties of gas seals of the engine are simulated using a simulation program developed for this case, and the results are utilized in preliminary main design parameter selection. The engine simulation program was developed by combining and modifying the source codes of the simulation and calculation programs obtained from Helsinki University of Technology, Tampere University of Technology, and Lappeenranta University of Technology. Because of the contact-free labyrinth seal used in the piston, the efficiency of the motor is lower than the efficiency of a conventional motor with oil lubricated piston rings. On the other hand, the lack of bearing losses, and the lack of losses associated with a crankshaft system and a gearbox, as well as the lack of lubrication oil expenses, compensates this effect. As a net result, this new motor would perform slightly better than the conventional one. Being completely oil-free, it is very environmentally friendly, and its exhaust gases are completely free of oil residuals which are causing problems in normal gas motors.

  7. Free-piston Stirling engine system considerations for various space power applications

    NASA Astrophysics Data System (ADS)

    Dochat, George R.; Dhar, Manmohan

    1991-01-01

    The U.S. Government is evaluating power requirements for future space applications. As power requirements increase solar or nuclear dynamic systems become increasingly attractive. Free-Piston Stirling Engines (FPSE) have the potential to provide high reliability, long life, and efficient operation. Therefore, they are excellent candidates for the dynamic power conversion module of a space-based, power-generating system. FPSE can be coupled with many potential heat sources (radioisotope, solar, or nuclear reactor), various heat input systems (pumped loop, heat pipe), heat rejection (pumped loop or heat pipe), and various power management and distribution systems (AC, DC, high or low voltage, and fixed or variable load). This paper will review potential space missions that can be met using free-piston Stirling engines and discusses options of various system integration approaches. Currently free-piston Stirling engine technology for space power applications is being developed under contract with NASA-Lewis Research Center. This paper will also briefly outline the program and recent progress.

  8. Lower-end dynamic characteristics of a magnetically coupled free-piston Stirling engine/compressor system

    NASA Astrophysics Data System (ADS)

    Chen, G.; McEntee, J.

    In a prototype, the engine power piston is connected to the compressor piston through a magnetic coupling; a linear starter is used to start the system and a variable-stiffness gas spring is used to resonate the system lower-end over the operating frequency range of the system. System characteristics of the lower end coupled through the coupling to the engine, and considerations of the engine response, are investigated analytically with a simplified model. The system analysis is also used to obtain an understanding of the free-piston Stirling engine/magnetic coupling/compressor assembly dynamic behavior for variations in engine power and lower-end resonance. In order for the machine to operate without excessively large forces transmitted through the magnetic coupling, the analysis indicates that both the engine and the compressor section should be independently resonant to keep the engine and the lower-end oscillating amplitude identical.

  9. System analysis of a piston steam engine employing the uniflow principle, a study in optimized performance

    NASA Technical Reports Server (NTRS)

    Peoples, J. A.

    1975-01-01

    Results are reported which were obtained from a mathematical model of a generalized piston steam engine configuration employing the uniflow principal. The model accounted for the effects of clearance volume, compression work, and release volume. A simple solution is presented which characterizes optimum performance of the steam engine, based on miles per gallon. Development of the mathematical model is presented. The relationship between efficiency and miles per gallon is developed. An approach to steam car analysis and design is presented which has purpose rather than lucky hopefulness. A practical engine design is proposed which correlates to the definition of the type engine used. This engine integrates several system components into the engine structure. All conclusions relate to the classical Rankine Cycle.

  10. Improvements in teaching aircraft engine design

    SciTech Connect

    Mattingly, J.D.; Heiser, W.H. Tennessee, University, Tullahoma )

    1992-07-01

    Aircraft gas turbine analysis and design pedagogy can be enriched through the incorporation improved preliminary engine thrust and fuel consumption models, novel computer programs for both aircraft system analysis and turbomechanical design, and a new perspective for engine-cycle analysis. Four computer programs have been developed for preliminary engine design; two of these automate aircraft system analysis, while another designs multistage axial-flow compressors and the last designs multistage axial-flow turbines. Student confusion with 'design-point' and 'off-design' concepts is by these means reduced. 6 refs.

  11. Numerical investigation of CAI Combustion in the Opposed- Piston Engine with Direct and Indirect Water Injection

    NASA Astrophysics Data System (ADS)

    Pyszczek, R.; Mazuro, P.; Teodorczyk, A.

    2016-09-01

    This paper is focused on the CAI combustion control in a turbocharged 2-stroke Opposed-Piston (OP) engine. The barrel type OP engine arrangement is of particular interest for the authors because of its robust design, high mechanical efficiency and relatively easy incorporation of a Variable Compression Ratio (VCR). The other advantage of such design is that combustion chamber is formed between two moving pistons - there is no additional cylinder head to be cooled which directly results in an increased thermal efficiency. Furthermore, engine operation in a Controlled Auto-Ignition (CAI) mode at high compression ratios (CR) raises a possibility of reaching even higher efficiencies and very low emissions. In order to control CAI combustion such measures as VCR and water injection were considered for indirect ignition timing control. Numerical simulations of the scavenging and combustion processes were performed with the 3D CFD multipurpose AVL Fire solver. Numerous cases were calculated with different engine compression ratios and different amounts of directly and indirectly injected water. The influence of the VCR and water injection on the ignition timing and engine performance was determined and their application in the real engine was discussed.

  12. Supersonic fan engines for military aircraft

    NASA Technical Reports Server (NTRS)

    Franciscus, L. C.

    1983-01-01

    Engine performance and mission studies were performed for turbofan engines with supersonic through-flow fans. A Mach 2.4 CTOL aircraft was used in the study. Two missions were considered: a long range penetrator mission and a long range intercept mission. The supersonic fan engine is compared with an augmented mixed flow turbofan in terms of mission radius for a fixed takeoff gross weight of 75,000 lbm. The mission radius of aircraft powered by supersonic fan engines could be 15 percent longer than aircraft powered with conventional turbofan engines at moderate thrust to gross weight ratios. The climb and acceleration performance of the supersonic fan engines is better than that of the conventional turbofan engines.

  13. Integrated engine generator for aircraft secondary power

    NASA Technical Reports Server (NTRS)

    Secunde, R. R.

    1972-01-01

    An integrated engine-generator for aircraft secondary power generation is described. The concept consists of an electric generator located inside a turbojet or turbofan engine and both concentric with and driven by one of the main engine shafts. The electric power conversion equipment and generator controls are located in the aircraft. When properly rated, the generator serves as an engine starter as well as a source of electric power. This configuration reduces or eliminates the need for an external gear box on the engine and permits reduction in the nacelle diameter.

  14. Cycle Counting Methods of the Aircraft Engine

    ERIC Educational Resources Information Center

    Fedorchenko, Dmitrii G.; Novikov, Dmitrii K.

    2016-01-01

    The concept of condition-based gas turbine-powered aircraft operation is realized all over the world, which implementation requires knowledge of the end-of-life information related to components of aircraft engines in service. This research proposes an algorithm for estimating the equivalent cyclical running hours. This article provides analysis…

  15. A numerical model on thermodynamic analysis of free piston Stirling engines

    NASA Astrophysics Data System (ADS)

    Mou, Jian; Hong, Guotong

    2017-02-01

    In this paper, a new numerical thermodynamic model which bases on the energy conservation law has been used to analyze the free piston Stirling engine. In the model all data was taken from a real free piston Stirling engine which has been built in our laboratory. The energy conservation equations have been applied to expansion space and compression space of the engine. The equation includes internal energy, input power, output power, enthalpy and the heat losses. The heat losses include regenerative heat conduction loss, shuttle heat loss, seal leakage loss and the cavity wall heat conduction loss. The numerical results show that the temperature of expansion space and the temperature of compression space vary with the time. The higher regeneration effectiveness, the higher efficiency and bigger output work. It is also found that under different initial pressures, the heat source temperature, phase angle and engine work frequency pose different effects on the engine’s efficiency and power. As a result, the model is expected to be a useful tool for simulation, design and optimization of Stirling engines.

  16. New potentials for conventional aircraft when powered by hydrogen-enriched gasoline

    NASA Technical Reports Server (NTRS)

    Menard, W. A.; Moynihan, P. I.; Rupe, J. H.

    1976-01-01

    Hydrogen enrichment for aircraft piston engines is studied. The feasibility is examined of inflight injection of hydrogen in general aviation aircraft engines to reduce fuel consumption and to lower emission levels. Results are summarized.

  17. Review of Aircraft Engine Fan Noise Reduction

    NASA Technical Reports Server (NTRS)

    VanZante, Dale

    2008-01-01

    Aircraft turbofan engines incorporate multiple technologies to enhance performance and durability while reducing noise emissions. Both careful aerodynamic design of the fan and proper installation of the fan into the system are requirements for achieving the performance and acoustic objectives. The design and installation characteristics of high performance aircraft engine fans will be discussed along with some lessons learned that may be applicable to spaceflight fan applications.

  18. Aircraft

    DTIC Science & Technology

    2002-01-01

    Company, Washington, DC Boeing Commercial Aircraft Division, Seattle, WA and Long Beach, CA Boeing Military Aircraft and Missile Division, St. Louis, MO and... aircraft ; military fixed-wing aircraft ; rotorcraft (helicopters and tiltrotor aircraft ); and aircraft jet engines. Two companies dominate the commercial... aircraft business, Boeing and Airbus. Four companies dominate the military fixed-wing market, Boeing, Lockheed Martin, BAE Systems, and European

  19. The Further Development of Heat-Resistant Materials for Aircraft Engines

    NASA Technical Reports Server (NTRS)

    Bollenrath, Franz

    1946-01-01

    The present report deals with the problems involved in the greater utilization and development of aircraft engine materials, and specifically; piston materials, cylinder heads, exhaust valves, and exhaust gas turbine blading. The blades of the exhaust gas turbine are likely to be the highest stressed components of modern power plants from a thermal-mechanical and chemical standpoint, even though the requirements on exhaust valves of engines with gasoline injection are in general no less stringent. For the fire plate in Diesel engines the specifications for mechanical strength and design are not so stringent, and the question of heat resistance, which under these circumstances is easier obtainable, predominates.

  20. Theoretical Evaluation of the Maximum Work of Free-Piston Engine Generators

    NASA Astrophysics Data System (ADS)

    Kojima, Shinji

    2017-01-01

    Utilizing the adjoint equations that originate from the calculus of variations, we have calculated the maximum thermal efficiency that is theoretically attainable by free-piston engine generators considering the work loss due to friction and Joule heat. Based on the adjoint equations with seven dimensionless parameters, the trajectory of the piston, the histories of the electric current, the work done, and the two kinds of losses have been derived in analytic forms. Using these we have conducted parametric studies for the optimized Otto and Brayton cycles. The smallness of the pressure ratio of the Brayton cycle makes the net work done negative even when the duration of heat addition is optimized to give the maximum amount of heat addition. For the Otto cycle, the net work done is positive, and both types of losses relative to the gross work done become smaller with the larger compression ratio. Another remarkable feature of the optimized Brayton cycle is that the piston trajectory of the heat addition/disposal process is expressed by the same equation as that of an adiabatic process. The maximum thermal efficiency of any combination of isochoric and isobaric heat addition/disposal processes, such as the Sabathe cycle, may be deduced by applying the methods described here.

  1. Free-piston Stirling hydraulic engine and drive system for automobiles

    NASA Technical Reports Server (NTRS)

    Beremand, D. G.; Slaby, J. G.; Nussle, R. C.; Miao, D.

    1982-01-01

    The calculated fuel economy for an automotive free piston Stirling hydraulic engine and drive system using a pneumatic accumulator with the fuel economy of both a conventional 1980 spark ignition engine in an X body class vehicle and the estimated fuel economy of a 1984 spark ignition vehicle system are compared. The results show that the free piston Stirling hydraulic system with a two speed transmission has a combined fuel economy nearly twice that of the 1980 spark ignition engine - 21.5 versus 10.9 km/liter (50.7 versus 25.6 mpg) under comparable conditions. The fuel economy improvement over the 1984 spark ignition engine was 81 percent. The fuel economy sensitivity of the Stirling hydraulic system to system weight, number of transmission shifts, accumulator pressure ratio and maximum pressure, auxiliary power requirements, braking energy recovery, and varying vehicle performance requirements are considered. An important finding is that a multispeed transmission is not required. The penalty for a single speed versus a two speed transmission is about a 12 percent drop in combined fuel economy to 19.0 km/liter (44.7 mpg). This is still a 60 percent improvement in combined fuel economy over the projected 1984 spark ignition vehicle.

  2. Start-up and control method and apparatus for resonant free piston Stirling engine

    DOEpatents

    Walsh, Michael M.

    1984-01-01

    A resonant free-piston Stirling engine having a new and improved start-up and control method and system. A displacer linear electrodynamic machine is provided having an armature secured to and movable with the displacer and having a stator supported by the Stirling engine housing in juxtaposition to the armature. A control excitation circuit is provided for electrically exciting the displacer linear electrodynamic machine with electrical excitation signals having substantially the same frequency as the desired frequency of operation of the Stirling engine. The excitation control circuit is designed so that it selectively and controllably causes the displacer electrodynamic machine to function either as a generator load to extract power from the displacer or the control circuit selectively can be operated to cause the displacer electrodynamic machine to operate as an electric drive motor to apply additional input power to the displacer in addition to the thermodynamic power feedback to the displacer whereby the displacer linear electrodynamic machine also is used in the electric drive motor mode as a means for initially starting the resonant free-piston Stirling engine.

  3. Controllability of Free-piston Stirling Engine/linear Alternator Driving a Dynamic Load

    NASA Technical Reports Server (NTRS)

    Kankam, M. David; Rauch, Jeffrey S.

    1994-01-01

    This paper presents the dynamic behavior of a Free-Piston Stirling Engine/linear alternator (FPSE/LA) driving a single-phase fractional horse-power induction motor. The controllability and dynamic stability of the system are discussed by means of sensitivity effects of variations in system parameters, engine controller, operating conditions, and mechanical loading on the induction motor. The approach used expands on a combined mechanical and thermodynamic formulation employed in a previous paper. The application of state-space technique and frequency domain analysis enhances understanding of the dynamic interactions. Engine-alternator parametric sensitivity studies, similar to those of the previous paper, are summarized. Detailed discussions are provided for parametric variations which relate to the engine controller and system operating conditions. The results suggest that the controllability of a FPSE-based power system is enhanced by proper operating conditions and built-in controls.

  4. Analysis of oil consumption in cylinder of diesel engine for optimization of piston rings

    NASA Astrophysics Data System (ADS)

    Zhang, Junhong; Zhang, Guichang; He, Zhenpeng; Lin, Jiewei; Liu, Hai

    2013-01-01

    The performance and particulate emission of a diesel engine are affected by the consumption of lubricating oil. Most studies on oil consumption mechanism of the cylinder have been done by using the experimental method, however they are very costly. Therefore, it is very necessary to study oil consumption mechanism of the cylinder and obtain the accurate results by the calculation method. Firstly, four main modes of lubricating oil consumption in cylinder are analyzed and then the oil consumption rate under common working conditions are calculated for the four modes based on an engine. Then, the factors that affect the lubricating oil consumption such as working conditions, the second ring closed gap, the elastic force of the piston rings are also investigated for the four modes. The calculation results show that most of the lubricating oil is consumed by evaporation on the liner surface. Besides, there are three other findings: (1) The oil evaporation from the liner is determined by the working condition of an engine; (2) The increase of the ring closed gap reduces the oil blow through the top ring end gap but increases blow-by; (3) With the increase of the elastic force of the ring, both the left oil film thickness and the oil throw-off at the top ring decrease. The oil scraping of the piston top edge is consequently reduced while the friction loss between the rings and the liner increases. A neural network prediction model of the lubricating oil consumption in cylinder is established based on the BP neural network theory, and then the model is trained and validated. The main piston rings parameters which affect the oil consumption are optimized by using the BP neural network prediction model and the prediction accuracy of this BP neural network is within 8%, which is acceptable for normal engineering applications. The oil consumption is also measured experimentally. The relative errors of the calculated and experimental values are less than 10%, verifying the

  5. Engine selection for transport and combat aircraft

    NASA Technical Reports Server (NTRS)

    Dugan, J. F., Jr.

    1972-01-01

    The procedures that are used to select engines for transport and combat aircraft are discussed. In general, the problem is to select the engine parameters including engine size in such a way that all constraints are satisfied and airplane performance is maximized. This is done for four different classes of aircraft: (1) a long haul conventional takeoff and landing (CTOL) transport, (2) a short haul vertical takeoff and landing (VTOL) transport, (3) a long range supersonic transport (SST), and (4) a fighter aircraft. For the commercial airplanes the critical constraints have to do with noise while for the fighter, maneuverability requirements define the engine. Generally, the resultant airplane performance (range or payload) is far less than that achievable without these constraints and would suffer more if nonoptimum engines were selected.

  6. 77 FR 44429 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-30

    ... this AD: Aeromot AMT 300 Turbo Super Ximango and Stemme S10 VT have a Rotax 914 engine installed, not a... certificate holder Aircraft model Engine model Aeromot-Ind stria AMT-200 912 A2 Mec nico- Metal rgica...

  7. Nitrided-steel Piston Rings for Engines of High Specific Power

    DTIC Science & Technology

    1944-04-01

    cooperation with the Borg-Vfamer Corporation , Spring Division, Bollwood, 111. The nitrided-steel piston rings were performanco-tested In single-cylinder...engines rjider duot lnjeation have :<eon reported by the V ight Aeronautical Corpor - ation, Thoao t03ta showed that the nltrlded-steol rir^;o are...ARB No. Ho. 4D82 Fig. 6 f .’ -»» 200 400 600 800 Temperatura •°F 1000 Figure 6.- Effect of plston-rlng temperature on diametral

  8. Preliminary results from a four-working space, double-acting piston, Stirling engine controls model

    NASA Technical Reports Server (NTRS)

    Daniele, C. J.; Lorenzo, C. F.

    1980-01-01

    A four working space, double acting piston, Stirling engine simulation is being developed for controls studies. The development method is to construct two simulations, one for detailed fluid behavior, and a second model with simple fluid behaviour but containing the four working space aspects and engine inertias, validate these models separately, then upgrade the four working space model by incorporating the detailed fluid behaviour model for all four working spaces. The single working space (SWS) model contains the detailed fluid dynamics. It has seven control volumes in which continuity, energy, and pressure loss effects are simulated. Comparison of the SWS model with experimental data shows reasonable agreement in net power versus speed characteristics for various mean pressure levels in the working space. The four working space (FWS) model was built to observe the behaviour of the whole engine. The drive dynamics and vehicle inertia effects are simulated. To reduce calculation time, only three volumes are used in each working space and the gas temperature are fixed (no energy equation). Comparison of the FWS model predicted power with experimental data shows reasonable agreement. Since all four working spaces are simulated, the unique capabilities of the model are exercised to look at working fluid supply transients, short circuit transients, and piston ring leakage effects.

  9. 77 FR 39623 - Airworthiness Standards: Aircraft Engines; Technical Amendment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ... Part 33 [Amendment No. 33-33] Airworthiness Standards: Aircraft Engines; Technical Amendment AGENCY... amendment clarifies aircraft engine vibration test requirements in the airworthiness standards. The clarification is in response to inquiries from applicants requesting FAA engine type certifications...

  10. Experimental Investigation of Piston Heat Transfer in a Light Duty Engine Under Conventional Diesel, Homogeneous Charge Compression Ignition, and Reactivity Controlled Compression Ignition Combustion Regimes

    DTIC Science & Technology

    2014-02-13

    For Official Use Only UNCLASSIFIED Experimental Investigation of Piston Heat Transfer in a Light Duty Engine Under Conventional Diesel...Now affiliated with U.S. Army TARDEC ** University of Wisconsin-Madison Sandia National Laboratory Advanced Engine Combustion Meeting February...Experimental Investigation of Piston Heat Transfer in a Light Duty Engine Under Conventional Diesel, Homogeneous Charge Compression Ignition, and Reactivity

  11. Research on Modelling of Aviation Piston Engine for the Hardware-in-the-loop Simulation

    NASA Astrophysics Data System (ADS)

    Yu, Bing; Shu, Wenjun; Bian, Wenchao

    2016-11-01

    In order to build the aero piston engine model which is real-time and accurate enough to operating conditions of the real engine for hardware in the loop simulation, the mean value model is studied. Firstly, the air-inlet model, the fuel model and the power-output model are established separately. Then, these sub models are combined and verified in MATLAB/SIMULINK. The results show that the model could reflect the steady-state and dynamic performance of aero engine, the errors between the simulation results and the bench test data are within the acceptable range. The model could be applied to verify the logic performance and control strategy of controller in the hardware-in-the-loop (HIL) simulation.

  12. Analysis of thermal stress of the piston during non-stationary heat flow in a turbocharged Diesel engine

    NASA Astrophysics Data System (ADS)

    Gustof, P.; Hornik, A.

    2016-09-01

    In the paper, numeric calculations of thermal stresses of the piston in a turbocharged Diesel engine in the initial phase of its work were carried out based on experimental studies and the data resulting from them. The calculations were made using a geometrical model of the piston in a five-cylinder turbocharged Diesel engine with a capacity of about 2300 cm3, with a direct fuel injection to the combustion chamber and a power rating of 85 kW. In order to determine the thermal stress, application of own mathematical models of the heat flow in characteristic surfaces of the piston was required to show real processes occurring on the surface of the analysed component. The calculations were performed using a Geostar COSMOS/M program module. A three-dimensional geometric model of the piston was created in this program based on a real component, in order to enable the calculations and analysis of thermal stresses during non-stationary heat flow. Modelling of the thermal stresses of the piston for the engine speed n=4250 min-1 and engine load λ=1.69 was carried out.

  13. Multi-objective optimization and design for free piston Stirling engines based on the dimensionless power

    NASA Astrophysics Data System (ADS)

    Mou, Jian; Hong, Guotong

    2017-02-01

    In this paper, the dimensionless power is used to optimize the free piston Stirling engines (FPSE). The dimensionless power is defined as a ratio of the heat power loss and the output work. The heat power losses include the losses of expansion space, heater, regenerator, cooler and the compression space and every kind of the heat loss calculated by empirical formula. The output work is calculated by the adiabatic model. The results show that 82.66% of the losses come from the expansion space and 54.59% heat losses of expansion space come from the shuttle loss. At different pressure the optimum bore-stroke ratio, heat source temperature, phase angle and the frequency have different values, the optimum phase angles increase with the increase of pressure, but optimum frequencies drop with the increase of pressure. However, no matter what the heat source temperature, initial pressure and frequency are, the optimum ratios of piston stroke and displacer stroke all about 0.8. The three-dimensional diagram is used to analyse Stirling engine. From the three-dimensional diagram the optimum phase angle, frequency and heat source temperature can be acquired at the same time. This study offers some guides for the design and optimization of FPSEs.

  14. 75 FR 70098 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ... crankcase surface to remove any oil. (ii) Warm up the engine to a minimum oil temperature of 50 degrees C (120 degrees F). Information about warming up the engine can be found in the applicable line... Aircraft Engines 912 A series engine with a crankcase assembly S/N up to and including S/N...

  15. Overview of NASA Lewis Research Center free-piston Stirling engine technology activities applicable to space power systems

    NASA Astrophysics Data System (ADS)

    Slaby, Jack G.

    A brief overview is presented of the development and technological activities of the free-piston Stirling engine. The engine started as a small scale fractional horsepower engine which demonstrated basic engine operating principles and the advantages of being hermetically sealed, highly efficient, and simple. It eventually developed into the free piston Stirling engine driven heat pump, and then into the SP-100 Space Reactor Power Program from which came the Space Power Demonstrator Engine (SPDE). The SPDE successfully operated for over 300 hr and delivered 20 kW of PV power to an alternator plunger. The SPDE demonstrated that a dynamic power conversion system can, with proper design, be balanced; and the engine performed well with externally pumped hydrostatic gas bearings.

  16. Overview of NASA Lewis Research Center free-piston Stirling engine technology activities applicable to space power systems

    NASA Technical Reports Server (NTRS)

    Slaby, Jack G.

    1987-01-01

    A brief overview is presented of the development and technological activities of the free-piston Stirling engine. The engine started as a small scale fractional horsepower engine which demonstrated basic engine operating principles and the advantages of being hermetically sealed, highly efficient, and simple. It eventually developed into the free piston Stirling engine driven heat pump, and then into the SP-100 Space Reactor Power Program from which came the Space Power Demonstrator Engine (SPDE). The SPDE successfully operated for over 300 hr and delivered 20 kW of PV power to an alternator plunger. The SPDE demonstrated that a dynamic power conversion system can, with proper design, be balanced; and the engine performed well with externally pumped hydrostatic gas bearings.

  17. On the dynamic response of pressure transmission lines in the research of helium-charged free piston Stirling engines

    NASA Technical Reports Server (NTRS)

    Miller, Eric L.; Dudenhoefer, James E.

    1989-01-01

    In free piston Stirling engine research the integrity of both amplitude and phase of the dynamic pressure measurements is critical to the characterization of cycle dynamics and thermodynamics. It is therefore necessary to appreciate all possible sources of signal distortion when designing pressure measurement systems for this type of research. The signal distortion inherent to pressure transmission lines is discussed. Based on results from classical analysis, guidelines are formulated to describe the dynamic response properties of a volume-terminated transmission tube for applications involving helium-charged free piston Stirling engines. The scope and limitations of the dynamic response analysis are considered.

  18. Free-piston Stirling engine/linear alternator 1000-hour endurance test

    NASA Technical Reports Server (NTRS)

    Rauch, J.; Dochat, G.

    1985-01-01

    The Free Piston Stirling Engine (FPSE) has the potential to be a long lived, highly reliable, power conversion device attractive for many product applications such as space, residential or remote site power. The purpose of endurance testing the FPSE was to demonstrate its potential for long life. The endurance program was directed at obtaining 1000 operational hours under various test conditions: low power, full stroke, duty cycle and stop/start. Critical performance parameters were measured to note any change and/or trend. Inspections were conducted to measure and compare critical seal/bearing clearances. The engine performed well throughout the program, completing more than 1100 hours. Hardware inspection, including the critical clearances, showed no significant change in hardware or clearance dimensions. The performance parameters did not exhibit any increasing or decreasing trends. The test program confirms the potential for long life FPSE applications.

  19. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Manufacture of new aircraft, aircraft..., DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.6 Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b)...

  20. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Manufacture of new aircraft, aircraft..., DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.6 Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b)...

  1. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Manufacture of new aircraft, aircraft..., DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.6 Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b)...

  2. Modeling and Simulation of a Free-Piston Engine with Electrical Generator Using HCCI Combustion

    NASA Astrophysics Data System (ADS)

    Alrbai, Mohammad

    Free-piston engines have the potential to challenge the conventional crankshaft engines by their design simplicity and higher operational efficiency. Many studies have been performed to overcome the limitations of the free-piston devices especially the stability and control issues. The investigations within the presented dissertation aim to satisfy many objectives by employing the approach of chemical kinetics to present the combustion process in the free-piston engine. This approach in addition to its advanced accuracy over the empirical methods, it has many other features like the ability to analyze the engine emissions. The effect of the heat release rate (HRR) on the engine performance is considered as the main objective. Understanding the relation between the HRR and the piston dynamics helps in enhancing the system efficiency and identifying the parameters that affect the overall performance. The dissertation covers some other objectives that belongs to the combustion phasing. Exhaust gas recirculation (EGR), equivalence ratio and the intake temperature represent the main combustion parameters, which have been discussed in this dissertation. To obtain the stability in system performance, the model requires a proper controller to simulate the operation and manage the different system parameters; for this purpose, different controlling techniques have been employed. In addition, the dissertation considers some other topics like engine emissions, fuels and fuels mechanisms. The model of the study describes the processes within a single cylinder, two stroke engine, which includes springs to support higher frequencies, reduce cyclic variations and sustain the engine compression ratio. An electrical generator presents the engine load; the generator supports different load profiles and play the key role in controlling the system. The 1st law of thermodynamics and Newton's 2nd law are applied to couple the piston dynamics with the engine thermodynamics. The model

  3. Method of vibration isolating an aircraft engine

    NASA Technical Reports Server (NTRS)

    Bender, Stanley I. (Inventor); Butler, Lawrence (Inventor); Dawes, Peter W. (Inventor)

    1991-01-01

    A method for coupling an engine to a support frame for mounting to a fuselage of an aircraft using a three point vibration isolating mounting system in which the load reactive forces at each mounting point are statically and dynamically determined. A first vibration isolating mount pivotably couples a first end of an elongated support beam to a stator portion of an engine with the pivoting action of the vibration mount being oriented such that it is pivotable about a line parallel to a center line of the engine. An aft end of the supporting frame is coupled to the engine through an additional pair of vibration isolating mounts with the mounts being oriented such that they are pivotable about a circumference of the engine. The aft mounts are symmetrically spaced to each side of the supporting frame by 45 degrees. The relative orientation between the front mount and the pair of rear mounts is such that only the rear mounts provide load reactive forces parallel to the engine center line, in support of the engine to the aircraft against thrust forces. The forward mount is oriented so as to provide only radial forces to the engine and some lifting forces to maintain the engine in position adjacent a fuselage. Since each mount is connected to provide specific forces to support the engine, forces required of each mount are statically and dynamically determinable.

  4. Aircraft engine mathematical model - linear system approach

    NASA Astrophysics Data System (ADS)

    Rotaru, Constantin; Roateşi, Simona; Cîrciu, Ionicǎ

    2016-06-01

    This paper examines a simplified mathematical model of the aircraft engine, based on the theory of linear and nonlinear systems. The dynamics of the engine was represented by a linear, time variant model, near a nominal operating point within a finite time interval. The linearized equations were expressed in a matrix form, suitable for the incorporation in the MAPLE program solver. The behavior of the engine was included in terms of variation of the rotational speed following a deflection of the throttle. The engine inlet parameters can cover a wide range of altitude and Mach numbers.

  5. 78 FR 54385 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-04

    ... condition exists and is likely to exist or develop on other products of the same type design. FAA's.... Table 1 of Paragraph (c)--Affected Airplanes Type certificate holder Aircraft model Engine model Aeromot-Ind stria AMT-200 912 A2 Mec nico- Metal rgica Ltda. Diamond Aircraft Industries...... HK 36 R...

  6. Aircraft Engineering Conference 1934 - Full Scale Tunnel

    NASA Technical Reports Server (NTRS)

    1934-01-01

    Gathered together in the only facility big enough to hold them, attendees at Langleys 1934 aircraft Engineering Conference pose in the Full Scale Wind Tunnel underneath a Boeing P-26A Peashooter. Present, among other notables, were Orville Wright, Charles Lindbergh, and Howard Hughes.

  7. Electronic materials testing in commercial aircraft engines

    NASA Astrophysics Data System (ADS)

    Brand, Dieter

    A device for the electronic testing of materials used in commercial aircraft engines is described. The instrument can be used for ferromagnetic, ferrimagnetic, and nonferromagnetic metallic materials, and it functions either optically or acoustically. The design of the device is described and technical data are given. The device operates under the principle of controlled self-inductivity. Its mode of operation is described.

  8. Flow Forming of Aircraft Engine Components

    DTIC Science & Technology

    2006-05-01

    Canada 1000 Marie Victorin, Longueuil Québec J4G 1A1 CANADA jean.Savoie@pwc.ca ABSTRACT Aircraft engine components are often an assembly of...1000 Marie Victorin, Longueuil Québec J4G 1A1 CANADA 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES

  9. RE-1000 free-piston Stirling engine hydraulic output system description

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.; Geng, Steven M.

    1987-01-01

    The NASA Lewis Research Center was involved in free-piston Stirling engine research since 1976. Most of the work performed in-house was related to characterization of the RE-1000 engine. The data collected from the RE-1000 tests were intended to provide a data base for the validation of Stirling cycle simulations. The RE-1000 was originally build with a dashpot load system which did not convert the output of the engine into useful power, but was merely used as a load for the engine to work against during testing. As part of the interagency program between NASA Lewis and the Oak Ridge National Laboratory, (ORNL), the RE-1000 was converted into a configuration that produces useable hydraulic power. A goal of the hydraulic output conversion effort was to retain the same thermodynamic cycle that existed with the dashpot loaded engine. It was required that the design must provide a hermetic seal between the hydraulic fluid and the working gas of the engine. The design was completed and the hardware was fabricated. The RE-1000 was modified in 1985 to the hydraulic output configuration. The early part of the RE-1000 hydraulic output program consisted of modifying hardware and software to allow the engine to run at steady-state conditions. A complete description of the engine is presented in sufficient detail so that the device can be simulated on a computer. Tables are presented showing the masses of the oscillating components and key dimensions needed for modeling purposes. Graphs are used to indicate the spring rate of the diaphragms used to separate the helium of the working and bounce space from the hydraulic fluid.

  10. Free-piston Stirling engine conceptual design and technologies for space power, phase 1

    NASA Technical Reports Server (NTRS)

    Penswick, L. Barry; Beale, William T.; Wood, J. Gary

    1990-01-01

    As part of the SP-100 program, a phase 1 effort to design a free-piston Stirling engine (FPSE) for a space dynamic power conversion system was completed. SP-100 is a combined DOD/DOE/NASA program to develop nuclear power for space. This work was completed in the initial phases of the SP-100 program prior to the power conversion concept selection for the Ground Engineering System (GES). Stirling engine technology development as a growth option for SP-100 is continuing after this phase 1 effort. Following a review of various engine concepts, a single-cylinder engine with a linear alternator was selected for the remainder of the study. The relationships of specific mass and efficiency versus temperature ratio were determined for a power output of 25 kWe. This parametric study was done for a temperature ratio range of 1.5 to 2.0 and for hot-end temperatures of 875 K and 1075 K. A conceptual design of a 1080 K FPSE with a linear alternator producing 25 kWe output was completed. This was a single-cylinder engine designed for a 62,000 hour life and a temperature ratio of 2.0. The heat transport systems were pumped liquid-metal loops on both the hot and cold ends. These specifications were selected to match the SP-100 power system designs that were being evaluated at that time. The hot end of the engine used both refractory and superalloy materials; the hot-end pressure vessel featured an insulated design that allowed use of the superalloy material. The design was supported by the hardware demonstration of two of the component concepts - the hydrodynamic gas bearing for the displacer and the dynamic balance system. The hydrodynamic gas bearing was demonstrated on a test rig. The dynamic balance system was tested on the 1 kW RE-1000 engine at NASA Lewis.

  11. Alaskan flight trials of a synthetic vision system for instrument landings of a piston twin aircraft

    NASA Astrophysics Data System (ADS)

    Barrows, Andrew K.; Alter, Keith W.; Jennings, Chad W.; Powell, J. D.

    1999-07-01

    Stanford University has developed a low-cost prototype synthetic vision system and flight tested it onboard general aviation aircraft. The display aids pilots by providing an 'out the window' view, making visualization of the desired flight path a simple task. Predictor symbology provides guidance on straight and curved paths presented in a 'tunnel- in-the-sky' format. Based on commodity PC hardware to achieve low cost, the Tunnel Display system uses differential GPS (typically from Stanford prototype Wide Area Augmentation System hardware) for positioning and GPS-aided inertial sensors for attitude determination. The display has been flown onboard Piper Dakota and Beechcraft Queen Air aircraft at several different locations. This paper describes the system, its development, and flight trials culminating with tests in Alaska during the summer of 1998. Operational experience demonstrated the Tunnel Display's ability to increase flight- path following accuracy and situational awareness while easing the task instrument flying.

  12. Increasing reliability of gas-air systems of piston and combined internal combustion engines by improving thermal and mechanic flow characteristics

    NASA Astrophysics Data System (ADS)

    Brodov, Yu. M.; Grigor'ev, N. I.; Zhilkin, B. P.; Plotnikov, L. V.; Shestakov, D. S.

    2015-12-01

    Results of experimental study of thermal and mechanical characteristics of gas exchange flow in piston and combined engines are presented. Ways for improving intake and exhaust processes to increase reliability of gas-air engine systems are proposed.

  13. Free-piston engine linear generator for hybrid vehicles modeling study. Interim report, January-August 1994

    SciTech Connect

    Callahan, T.J.; Ingram, S.K.

    1995-05-01

    Development of a free piston engine linear generator was investigated for use as an auxiliary power unit for a hybrid electric vehicle. The main focus of the program was to develop an efficient linear generator concept to convert the piston motion directly into electrical power. Computer modeling techniques were used to evaluate five different designs for linear generators. These designs included permanent magnet generators, reluctance generators, linear DC generators, and two and three-coil induction generators. The efficiency of the linear generator was highly dependent on the design concept. The two-coil induction generator was determined to be the best design, with an efficiency of approximately 90 percent.

  14. Recent Advances in Design of Low Cost Film Concentrator and Low Pressure Free Piston Stirling Engines for Solar Power

    NASA Technical Reports Server (NTRS)

    Kleinwaechter, J.; Kleinwaechter, H.; Beale, W.

    1984-01-01

    The free piston Stirling-linear alternator was shown to be scalable to power levels of tens of kilowatts in a form which is simple, efficient, long lived and relatively inexpensive. It avoids entirely the vexing problem of high pressure shaft, and its control requirements are not severe nor do they represent a significant threat to durability. Linear alternators have demonstrated high efficiency and moderate weight, and are capable of delivering 3 phase power from single machines without great increases of cost or complexity. There remains no apparent impediments to the commercial exploitation of the free piston engine for solar electric power generation.

  15. 14 CFR 21.128 - Tests: aircraft engines.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tests: aircraft engines. 21.128 Section 21... engines. (a) Each person manufacturing aircraft engines under a type certificate only shall subject each engine (except rocket engines for which the manufacturer must establish a sampling technique) to...

  16. 14 CFR 21.128 - Tests: aircraft engines.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Tests: aircraft engines. 21.128 Section 21... engines. (a) Each person manufacturing aircraft engines under a type certificate only shall subject each engine (except rocket engines for which the manufacturer must establish a sampling technique) to...

  17. Advanced aircraft engine materials trends

    NASA Technical Reports Server (NTRS)

    Dreshfield, R. L.; Gray, H. R.; Levine, S. R.; Signorelli, R.

    1981-01-01

    Recent activities of the Lewis Research Center are reviewed which are directed toward developing materials for rotating hot section components for aircraft gas turbines. Turbine blade materials activities are directed at increasing metal temperatures approximately 100 C compared to current directionally solidified alloys by use of oxide dispersion strengthening or tungsten alloy wire reinforcement of nickel or iron base superalloys. The application of thermal barrier coatings offers a promise of increasing gas temperatures an additional 100 C with current cooling technology. For turbine disk alloys, activities are directed toward reducing the cost of turbine disks by 50 percent through near net shape fabrication of prealloyed powders as well as towards improved performance. In addition, advanced alloy concepts and fabrication methods for dual alloy disks are being studied as having potential for improving the life of future high performance disks and reducing the amount of strategic materials required in these components.

  18. Diesel engine catalytic combustor system. [aircraft engines

    NASA Technical Reports Server (NTRS)

    Ream, L. W. (Inventor)

    1984-01-01

    A low compression turbocharged diesel engine is provided in which the turbocharger can be operated independently of the engine to power auxiliary equipment. Fuel and air are burned in a catalytic combustor to drive the turbine wheel of turbine section which is initially caused to rotate by starter motor. By opening a flapper value, compressed air from the blower section is directed to catalytic combustor when it is heated and expanded, serving to drive the turbine wheel and also to heat the catalytic element. To start, engine valve is closed, combustion is terminated in catalytic combustor, and the valve is then opened to utilize air from the blower for the air driven motor. When the engine starts, the constituents in its exhaust gas react in the catalytic element and the heat generated provides additional energy for the turbine section.

  19. A Preliminary Study of Fuel Injection and Compression Ignition as Applied to an Aircraft Engine Cylinder

    NASA Technical Reports Server (NTRS)

    Gardiner, Arthur W

    1927-01-01

    This report summarizes some results obtained with a single cylinder test engine at the Langley Field Laboratory during a preliminary investigation of the problem of applying fuel injection and compression ignition to aircraft engines. For this work a standard Liberty Engine cylinder was fitted with a high compression, 11.4 : 1 compression ratio, piston, and equipped with an airless injection system, including a primary fuel pump, an injection pump, and an automatic injection valve. The results obtained during this investigation have indicated the possibility of applying airless injection and compression ignition to a cylinder of this size, 8-inch bore by 7-inch stroke, when operating at engine speeds as high as 1,850 R. P. M. A minimum specific fuel consumption with diesel engine fuel oil of 0.30 pound per I. HP. Hour was obtained when developing about 16 B. HP. At 1,730 R. P. M.

  20. Development of a residential free-piston Stirling engine heat pump

    NASA Astrophysics Data System (ADS)

    Ackermann, Robert A.

    After several years of development, the free-piston Stirling engine heat pump (FPSE/HP) has successfully met proof-of-concept targets. The performance targets were achieved during an off-site test and evaluation program conducted at the Lennox Industries Engineering Center. The performance achieved for the module was a cooling thermal coefficient of performance (COP) of 0.91 and a heating thermal COP of 1.62. In addition to its performance achievement, the FPSE/HP module demonstrated good reliability in over 60 days of operation and ran stably and repeatably over a range of ambient conditions from 0 to 105 F. This paper will provide a description of the FPSE/HP module tested at Lennox, describe the developmental history of the FPSE/HP at Mechanical Technology Incorporated (MTI), and present the results of the Lennox tests. This work has been a collaborative effort of MTI, Oak Ridge National Laboratory (ORNL), the Department of Energy (DOE), and the Gas Research Institute (GRI). The financial and technical support provided by ORNL, DOE, and GRI was responsible for the success achieved.

  1. Helping Aircraft Engines Lighten Up

    NASA Technical Reports Server (NTRS)

    2004-01-01

    High-temperature polyimide/carbon fiber matrix composites are developed by the Polymers Branch at NASA's Glenn Research Center. These materials can withstand high temperatures and have good processing properties, which make them particularly useful for jet and rocket engines and for components such as fan blades, bushings, and duct segments. Applying polyimide composites as components for aerospace structures can lead to substantial vehicle weight reductions. A typical polyimide composite is made up of layers of carbon or glass fibers glued together by a high-temperature polymer to make the material strong, stiff, and lightweight. Organic molecules containing carbon, nitrogen, oxygen, and hydrogen within the polyimide keep the material s density low, resulting in the light weight. The strength of a component or part made from a polyimide comes mainly from the reinforcing high-strength fibers. The strength of the carbon fibers coupled with the stiffness of polyimides allows engineers to make a very rigid structure without it being massive. Another benefit of a polyimide s suitability for aerospace applications is its reduced need for machining. When polyimide parts are removed from a mold, they are nearly in their final shape. Usually, very little machining is needed before a part is ready for use.

  2. Composite piston

    NASA Technical Reports Server (NTRS)

    Taylor, Allan H. (Inventor)

    1988-01-01

    A composite piston structure is disclosed which provides a simple and reliable means for joining a carbon-carbon or ceramic piston cap with a metallic piston body. Attachment is achieved by means of a special geometry which compensates for differences in thermal expansion without complicated mechanical fastening devices. The shape employs a flange created by opposed frustoconical shapes with coincident vertices intersecting on the radial centerline of the piston in order to retain the piston cap. The use of carbon-carbon for the piston cap material allows a close fit between the piston and a cylinder wall, eliminating the need for piston rings. The elimination of extra mechanical parts of previous composite pistons provides a lightweight composite piston capable of extended high temperature operation.

  3. Aircraft Engine Exhaust Nozzle System for Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H. (Inventor); Czech, Michael J. (Inventor); Elkoby, Ronen (Inventor)

    2014-01-01

    The aircraft exhaust engine nozzle system includes a fan nozzle to receive a fan flow from a fan disposed adjacent to an engine disposed above an airframe surface of the aircraft, a core nozzle disposed within the fan nozzle and receiving an engine core flow, and a pylon structure connected to the core nozzle and structurally attached with the airframe surface to secure the engine to the aircraft.

  4. Aircraft Engine Sump Fire Mitigation

    NASA Technical Reports Server (NTRS)

    Rosenlieb, J. W.

    1973-01-01

    An investigation was performed of the conditions in which fires can result and be controlled within the bearing sump simulating that of a gas turbine engine; Esso 4040 Turbo Oil, Mobil Jet 2, and Monsanto MCS-2931 lubricants were used. Control variables include the oil inlet temperature, bearing temperature, oil inlet and scavenge rates, hot air inlet temperature and flow rate, and internal sump baffling. In addition to attempting spontaneous combustion, an electric spark and a rub (friction) mechanism were employed to ignite fires. Spontaneous combustion was not obtained; however, fires were readily ignited with the electric spark while using each of the three test lubricants. Fires were also ignited using the rub mechanism with the only test lubricant evaluated, Esso 4040. Major parameters controlling ignitions were: Sump configuration; Bearing and oil temperatures, hot air temperature and flow and bearing speed. Rubbing between stationary parts and rotating parts (eg. labyrinth seal and mating rub strip) is a very potent fire source suggesting that observed accidental fires in gas turbine sumps may well arise from this cause.

  5. Overview of NASA Lewis Research Center free-piston Stirling engine technology activities applicable to space power systems

    SciTech Connect

    Slaby, J.G.

    1987-01-01

    An overview is presented of the National Aeronautics and Space Administration (NASA) Lewis Research Center free-piston Stirling engine activities directed toward space-power application. One of the major elements of the program is the development of advanced power conversion concepts of which the Stirling cycle is a viable candidate. Under this program the research findings of the 25 kWe opposed-piston Space Power Demonstrator Engine (SPDE) are presented. Included in the SPDE discussion are initial differences between predicted and experimental power outputs and power output influenced by variations in regenerators. Projections are made for future space-power requirements over the next few decades. A cursory comparison is presented showing the mass benefits that a Stirling system has over a Brayton system for the same peak temperature and output power.

  6. A fuel-efficient cruise performance model for general aviation piston engine airplanes. Ph.D. Thesis. Final Report

    NASA Technical Reports Server (NTRS)

    Parkinson, R. C. H.

    1983-01-01

    A fuel-efficient cruise performance model which facilitates maximizing the specific range of General Aviation airplanes powered by spark-ignition piston engines and propellers is presented. Airplanes of fixed design only are considered. The uses and limitations of typical Pilot Operating Handbook cruise performance data, for constructing cruise performance models suitable for maximizing specific range, are first examined. These data are found to be inadequate for constructing such models. A new model of General Aviation piston-prop airplane cruise performance is then developed. This model consists of two subsystem models: the airframe-propeller-atmosphere subsystem model; and the engine-atmosphere subsystem model. The new model facilitates maximizing specific range; and by virtue of its implicity and low volume data storge requirements, appears suitable for airborne microprocessor implementation.

  7. Evaluation of Requirements for Militarization of 3-kW Free-Piston Stirling Engine Generator Set

    DTIC Science & Technology

    1982-01-01

    AD _ o EVALUATION OF REQUIREMENTS FOR •i MILITARIZATION OF 3-kW FREE-PISTON STIRLING ENGINE GENERATOR SET S Thomas J. Marusak Mechanical Technology ...PROGRAM ELEMENT. PROJECT, TASK Mechanical Technology Inc. AREA & WORK UNIT NUMSERS 968 Albany-Shaker Road Latham, NY 12110 11. CONTROLLING OFFICE NAME AND...Mechanical Technology Incorporated (MTI) is developing the FPSE for stationary com- mercial applications in the size range below 10 kW. Because of the poten

  8. Tribological systems as applied to aircraft engines

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1985-01-01

    Tribological systems as applied to aircraft are reviewed. The importance of understanding the fundamental concepts involved in such systems is discussed. Basic properties of materials which can be related to adhesion, friction and wear are presented and correlated with tribology. Surface processes including deposition and treatment are addressed in relation to their present and future application to aircraft components such as bearings, gears and seals. Lubrication of components with both liquids and solids is discussed. Advances in both new liquid molecular structures and additives for those structures are reviewed and related to the needs of advanced engines. Solids and polymer composites are suggested for increasing use and ceramic coatings containing fluoride compounds are offered for the extreme temperatures encountered in such components as advanced bearings and seals.

  9. Experimental Investigation of Piston Heat Transfer in a Light Duty Engine Under Conventional Diesel, Homogeneous Charge Compression Ignition, and Reactivity Controlled Compression Ignition Combustion Regimes

    DTIC Science & Technology

    2014-01-15

    and cylinder liners [10, 11]. More recently, measurements have been made on the piston surface with engines operating under RCCI and CDC combustion...An experimental study has been conducted to provide insight into heat transfer to the piston of a light-duty single- cylinder research engine under...timing or injection timing, when a single fuel is used. RCCI utilizes in- cylinder fuel reactivity stratification by utilizing a second fuel. Typically

  10. 76 FR 33660 - Airworthiness Directives; Austro Engine GmbH Model E4 Diesel Piston Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-09

    ... 2010-23-09, Amendment 39-16498 (75 FR 68179, November 5, 2010), for Austro Engine GmbH model E4 diesel...'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect... FR 68179, November 5, 2010), and adding the following new AD: Austro Engine GmbH: Docket No....

  11. Study of unconventional aircraft engines designed for low energy consumption

    NASA Technical Reports Server (NTRS)

    Gray, D. E.

    1976-01-01

    Declining U.S. oil reserves and escalating energy costs underline the need for reducing fuel consumption in aircraft engines. The most promising unconventional aircraft engines based on their potential for fuel savings and improved economics are identified. The engines installed in both a long-range and medium-range aircraft were evaluated. Projected technology advances are identified and evaluated for their state-of-readiness for application to a commercial transport. Programs are recommended for developing the necessary technology.

  12. Damage Propagation Modeling for Aircraft Engine Prognostics

    NASA Technical Reports Server (NTRS)

    Saxena, Abhinav; Goebel, Kai; Simon, Don; Eklund, Neil

    2008-01-01

    This paper describes how damage propagation can be modeled within the modules of aircraft gas turbine engines. To that end, response surfaces of all sensors are generated via a thermo-dynamical simulation model for the engine as a function of variations of flow and efficiency of the modules of interest. An exponential rate of change for flow and efficiency loss was imposed for each data set, starting at a randomly chosen initial deterioration set point. The rate of change of the flow and efficiency denotes an otherwise unspecified fault with increasingly worsening effect. The rates of change of the faults were constrained to an upper threshold but were otherwise chosen randomly. Damage propagation was allowed to continue until a failure criterion was reached. A health index was defined as the minimum of several superimposed operational margins at any given time instant and the failure criterion is reached when health index reaches zero. Output of the model was the time series (cycles) of sensed measurements typically available from aircraft gas turbine engines. The data generated were used as challenge data for the Prognostics and Health Management (PHM) data competition at PHM 08.

  13. In-cylinder flows of a motored four-stroke engine with flat-crown and slightly concave-crown pistons

    SciTech Connect

    Huang, R.F.; Yang, H.S.; Yeh, C.-N.

    2008-04-15

    The temporal and spatial evolution processes of the in-cylinder flow structures and turbulence intensities in the symmetry and offset planes of a motored four-valve, four-stroke engine during the intake and compression strokes are diagnosed by using a particle image velocimeter. Two pistons of different crown shapes (flat-crown and slightly concave-crown pistons) are studied. The inception, establishment, and evolution of the tumbling vortical flow structures during the intake and compression strokes are clearly depicted. Quantitative strengths of the rotating vortical flow motions are presented by a dimensionless parameter, the tumble ratio, which can represent the mean angular velocity of the vortices in the target plane. The turbulence intensity of the in-cylinder flow is also calculated by using the measured time-varying velocity data. The results show that the flat-crown piston induces higher bulk-averaged tumble ratio and turbulence intensity than the slightly concave-crown piston does because the tumble ratio and turbulence generated by the flat-crown piston in the offset planes during the compression stroke are particularly large. The engine with the flat-crown piston also presents larger torque and power outputs and lower hydrocarbon emission than that with the slightly concave-crown piston. This might be caused by the enhanced combustion in the engine cylinder due to the stronger tumble ratio and turbulence intensity. (author)

  14. 77 FR 1626 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-11

    ... determined the unsafe condition exists and is likely to exist or develop on other products of the same type... 40507; and (2) Certificated in any category. Table 1--Affected Airplanes Type certificate holder Aircraft model Engine model Aeromot-Ind stria AMT-200 912 A2 Mec nico- Metal rgica Ltda. Diamond...

  15. 77 FR 22187 - Technical Amendment; Airworthiness Standards-Aircraft Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-13

    ... Federal Aviation Administration 14 CFR Part 33 Technical Amendment; Airworthiness Standards--Aircraft.... SUMMARY: This amendment corrects a number of errors in the airworthiness standards for aircraft engine... additional burden on any person. List of Subjects 14 CFR Part 33 Air transportation, Aircraft,...

  16. A novel single-phase flux-switching permanent magnet linear generator used for free-piston Stirling engine

    NASA Astrophysics Data System (ADS)

    Zheng, Ping; Sui, Yi; Tong, Chengde; Bai, Jingang; Yu, Bin; Lin, Fei

    2014-05-01

    This paper investigates a novel single-phase flux-switching permanent-magnet (PM) linear machine used for free-piston Stirling engines. The machine topology and operating principle are studied. A flux-switching PM linear machine is designed based on the quasi-sinusoidal speed characteristic of the resonant piston. Considering the performance of back electromotive force and thrust capability, some leading structural parameters, including the air gap length, the PM thickness, the ratio of the outer radius of mover to that of stator, the mover tooth width, the stator tooth width, etc., are optimized by finite element analysis. Compared with conventional three-phase moving-magnet linear machine, the proposed single-phase flux-switching topology shows advantages in less PM use, lighter mover, and higher volume power density.

  17. The development of a free-piston Stirling engine power conversion system for multiple applications utilizing alternative fuel sources

    NASA Astrophysics Data System (ADS)

    Marusak, T. J.

    The thermodynamic and mechanical advantages of free-piston Stirling engines developed to date by NASA, and their future potential as small powerplants, are discussed. Applications include heat-pumps, mobile electric power systems, solar thermal electric power generation and multiple heat source-capability power systems. Existing prototypes have demonstrated engine efficiencies of 33% even at low output levels, and an advanced design capable of 40% efficiency and an output power of more than 3 kW is currently undergoing extensive testing.

  18. Piston Ring Pressure Distribution

    NASA Technical Reports Server (NTRS)

    Kuhn, M.

    1943-01-01

    The discovery and introduction of the internal combustion engine has resulted in a very rapid development in machines utilizing the action of a piston. Design has been limited by the internal components of the engine, which has been subjected to ever increasing thermal and mechanical stresses, Of these internal engine components, the piston and piston rings are of particular importance and the momentary position of engine development is not seldom dependent upon the development of both of the components, The piston ring is a well-known component and has been used in its present shape in the steam engine of the last century, Corresponding to its importance, the piston ring has been a rich field for creative activity and it is noteworthy that in spite of this the ring has maintained its shape through the many years. From the many and complicated designs which have been suggested as a packing between piston and cylinder wall hardly one suggestion has remained which does not resemble the original design of cast iron rectangular ring.

  19. Integrated engine-generator concept for aircraft electric secondary power

    NASA Technical Reports Server (NTRS)

    Secunde, R. R.; Macosko, R. P.; Repas, D. S.

    1972-01-01

    The integrated engine-generator concept of locating an electric generator inside an aircraft turbojet or turbofan engine concentric with, and driven by, one of the main engine shafts is discussed. When properly rated, the generator can serve as an engine starter as well as a generator of electric power. The electric power conversion equipment and generator controls are conveniently located in the aircraft. Preliminary layouts of generators in a large engine together with their physical sizes and weights indicate that this concept is a technically feasible approach to aircraft secondary power.

  20. 78 FR 65554 - Exhaust Emission Standards for New Aircraft Turbine Engines and Identification Plate for Aircraft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Parts 34 and 45 RIN 2120-AK15 Exhaust Emission Standards for New Aircraft Turbine Engines and Identification Plate for Aircraft Engines Correction In rule document 2013-24712, appearing on pages 63015-63017...

  1. Design study of a 15 kW free-piston Stirling engine-linear alternator for dispersed solar electric power systems

    NASA Technical Reports Server (NTRS)

    Dochat, G. R.; Chen, H. S.; Bhate, S.; Marusak, T.

    1979-01-01

    A conceptual design of a free piston solar Stirling engine-linear alternator which can be designed and developed to meet the requirements of a near-term solar test bed engine with minimum risks was developed. The conceptual design was calculated to have an overall system efficiency of 38% and provide 15kW electric output. The free piston engine design incorporates features such as gas bearings, close clearance seals, and gas springs. This design is hermetically sealed to provide long life, reliability, and maintenance free operation. An implementation assessment study performed indicates that the free piston solar Stirling engine-linear alternator can be manufactured at a reasonable price cost (direct labor plus material) of $2,500 per engine in production quantities of 25,000 units per year. Opportunity for significant reduction of cost was also identified.

  2. Conceptual design and cost analysis of hydraulic output unit for 15 kW free-piston Stirling engine

    NASA Technical Reports Server (NTRS)

    White, M. A.

    1982-01-01

    A long-life hydraulic converter with unique features was conceptually designed to interface with a specified 15 kW(e) free-piston Stirling engine in a solar thermal dish application. Hydraulic fluid at 34.5 MPa (5000 psi) is produced to drive a conventional hydraulic motor and rotary alternator. Efficiency of the low-maintenance converter design was calculated at 93.5% for a counterbalanced version and 97.0% without the counterbalance feature. If the converter were coupled to a Stirling engine with design parameters more typcial of high-technology Stirling engines, counterbalanced converter efficiency could be increased to 99.6%. Dynamic computer simulation studies were conducted to evaluate performance and system sensitivities. Production costs of the complete Stirling hydraulic/electric power system were evaluated at $6506 which compared with $8746 for an alternative Stirling engine/linear alternator system.

  3. Microfog lubrication for aircraft engine bearings

    NASA Technical Reports Server (NTRS)

    Rosenlieb, J. W.

    1976-01-01

    An analysis and system study was performed to provide design information regarding lubricant and coolant flow rates and flow paths for effective utilization of the lubricant and coolant in a once through bearing oil mist (microfog) and coolant air system. Both static and dynamic tests were performed. Static tests were executed to evaluate and calibrate the mist supply system. A total of thirteen dynamic step speed bearing tests were performed using four different lubricants and several different mist and air supply configurations. The most effective configuration consisted of supplying the mist and the major portion of the cooling air axially through the bearing. The results of these tests have shown the feasibility of using a once through oil mist and cooling air system to lubricate and cool a high speed, high temperature aircraft engine mainshaft bearing.

  4. Development of Casting Process for Pressings of Pistons of Car Augmented Engines

    NASA Astrophysics Data System (ADS)

    Korostelev, V. F.; Denisov, M. S.

    2017-01-01

    Results of a study aimed at formation of a single-phase fine-grained structure in pistons during their production process involving isostatic pressing of liquid metal prior to the start of crystallization, pressing of the crystallizing metal, and holding under pressure in the process of cooling to the shop temperature are presented.

  5. Effects of piston surface treatments on performance and emissions of a methanol-fueled, direct injection, stratified charge engine

    NASA Astrophysics Data System (ADS)

    West, B.; Green, J. B.

    1994-07-01

    The purpose of this study was to investigate the effects of thermal barrier coatings and/or surface treatments on the performance and emissions of a methanol-fueled, direct-injection, stratified-charge (DISC) engine. A Ricardo Hydra Mark III engine was used for this work and in previous experiments at Oak Ridge National Laboratory (ORNL). The primary focus of the study was to examine the effects of various piston insert surface treatments on hydrocarbon (HC) and oxides of nitrogen (NO(x)) emissions. Previous studies have shown that engines of this class have a tendency to perform poorly at low loads and have high unburned fuel emissions. A blank aluminum piston was modified to employ removable piston bowl inserts. Four different inserts were tested in the experiment: aluminum, stainless steel with a 1.27-mm (0.050-in.) air gap (to act as a thermal barrier), and two stainless steel/air-gap inserts with coatings. Two stainless steel inserts were dimensionally modified to account for the coating thickness (1.27-mm) and coated identically with partially stabilized zirconia (PSZ). One of the coated inserts then had an additional seal-coat applied. The coated inserts were otherwise identical to the stainless steel/air-gap insert (i.e., they employed the same 1.27-mm air gap). Thermal barrier coatings were employed in an attempt to increase combustion chamber surface temperatures, thereby reducing wall quenching and promoting more complete combustion of the fuel in the quench zone. The seal-coat was applied to the zirconia to reduce the surface porosity; previous research suggested that despite the possibly higher surface temperatures obtainable with a ceramic coating, the high surface area of a plasma-sprayed coating may actually allow fuel to adhere to the surface and increase the unburned fuel emissions and fuel consumption.

  6. 76 FR 72128 - Airworthiness Directives; Thielert Aircraft Engines GmbH (TAE) Reciprocating Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-22

    ... Directives; Thielert Aircraft Engines GmbH (TAE) Reciprocating Engines AGENCY: Federal Aviation... engines installed on, but not limited to, Diamond Aircraft Industries Model DA 42 airplanes. The existing... the PPRV, part number (P/N) 05-7212- E002801, on TAE 125-02-99 engines, from 300 hours to 600...

  7. Energy-state formulation of lumped volume dynamic equations with application to a simplified free piston Stirling engine

    NASA Technical Reports Server (NTRS)

    Daniele, C. J.; Lorenzo, C. F.

    1979-01-01

    Lumped volume dynamic equations are derived using an energy state formulation. This technique requires that kinetic and potential energy state functions be written for the physical system being investigated. To account for losses in the system, a Rayleigh dissipation function is formed. Using these functions, a Lagrangian is formed and using Lagrange's equation, the equations of motion for the system are derived. The results of the application of this technique to a lumped volume are used to derive a model for the free piston Stirling engine. The model was simplified and programmed on an analog computer. Results are given comparing the model response with experimental data.

  8. Energy-state formulation of lumped volume dynamic equations with application to a simplified free piston Stirling engine

    NASA Technical Reports Server (NTRS)

    Daniele, C. J.; Lorenzo, C. F.

    1979-01-01

    Lumped volume dynamic equations are derived using an energy-state formulation. This technique requires that kinetic and potential energy state functions be written for the physical system being investigated. To account for losses in the system, a Rayleigh dissipation function is also formed. Using these functions, a Lagrangian is formed and using Lagrange's equation, the equations of motion for the system are derived. The results of the application of this technique to a lumped volume are used to derive a model for the free-piston Stirling engine. The model was simplified and programmed on an analog computer. Results are given comparing the model response with experimental data.

  9. Integral Ring Carbon-Carbon Piston

    NASA Technical Reports Server (NTRS)

    Northam, G. Burton (Inventor)

    1999-01-01

    An improved structure for a reciprocating internal combustion engine or compressor piston fabricate from carbon-carbon composite materials is disclosed. An integral ring carbon-carbon composite piston, disclosed herein, reduces the need for piston rings and for small clearances by providing a small flexible, integral component around the piston that allows for variation in clearance due to manufacturing tolerances, distortion due to pressure and thermal loads, and variations in thermal expansion differences between the piston and cylinder liner.

  10. Development of the Junkers-diesel Aircraft Engine

    NASA Technical Reports Server (NTRS)

    Gasterstadt,

    1930-01-01

    The working process of the Junkers engine has resulted from a series of attempts to attain high performance and to control the necessarily rapid and complete combustion at extremely high speeds. The two main problems of Diesel engines in aircraft are addressed; namely, incomplete combustion and the greater weight of Diesel engine parts compared to gasoline engines.

  11. Carbon-carbon piston development

    NASA Technical Reports Server (NTRS)

    Gorton, Mark P.

    1994-01-01

    A new piston concept, made of carbon-carbon refractory-composite material, has been developed that overcomes a number of the shortcomings of aluminum pistons. Carbon-carbon material, developed in the early 1960's, is lighter in weight than aluminum, has higher strength and stiffness than aluminum and maintains these properties at temperatures over 2500 F. In addition, carbon-carbon material has a low coefficient of thermal expansion and excellent resistance to thermal shock. An effort, called the Advanced Carbon-Carbon Piston Program was started in 1986 to develop and test carbon-carbon pistons for use in spark ignition engines. The carbon-carbon pistons were designed to be replacements for existing aluminum pistons, using standard piston pin assemblies and using standard rings. Carbon-carbon pistons can potentially enable engines to be more reliable, more efficient and have greater power output. By utilizing the unique characteristics of carbon-carbon material a piston can: (1) have greater resistance to structural damage caused by overheating, lean air-fuel mixture conditions and detonation; (2) be designed to be lighter than an aluminum piston thus, reducing the reciprocating mass of an engine, and (3) be operated in a higher combustion temperature environment without failure.

  12. 78 FR 47228 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-05

    ... Engines GmbH Reciprocating Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of... Thielert Aircraft Engines GmbH TAE 125-01 reciprocating engines. This proposed AD was prompted by a report of engine power loss due to engine coolant contaminating the engine clutch. The design of the...

  13. A Method of Measuring Piston Temperatures

    NASA Technical Reports Server (NTRS)

    Pinkel, Benjamin; Mangniello, Eugene J

    1940-01-01

    A method that makes use of thermocouples has been developed to measure the temperature of engine pistons operating at high speeds. The thermocouples installed on the moving piston are connected with a potentiometer outside the engine by means of pneumatically operated plungers, which make contact with the piston thermocouples for about 10 crankshaft degrees at the bottom of the piston stroke. The equipment is operated satisfactory at engine speeds of 2,400 r.p.m. and shows promise of successful operation at higher engine speeds. Measurements of piston temperatures in a liquid-cooled compression-ignition engine and in an air-cooled spark-ignition are presented.

  14. Piston and valve assembly

    SciTech Connect

    Rolder, G. K.

    1985-10-01

    A downhole hydraulically actuated pump assembly of either the free or fixed type lifts formation fluid from the bottom of a borehole to the surface of the ground. The downhole pump has a power piston which actuates a production plunger. A valve means is concentrically arranged within the power piston. A stationary, hollow valve control rod extends through the power piston and through the valve means, with a lower marginal end of the control rod terminating within the production plunger. Power fluid flows through the control rod and to the valve means. As the power piston reciprocates within the engine cylinder, means on the control rod actuates the valve means between two alternant positions so that power fluid is applied to the bottom face of the power piston to thereby cause the power piston to reciprocate upward; and thereafter, the control rod causes the valve means to shift to the other position, whereupon spent power fluid is exhausted from the engine cylinder. The spent power fluid is admixed with production fluid and is conducted to the surface of the ground.

  15. Supersonic through-flow fan engine and aircraft mission performance

    NASA Technical Reports Server (NTRS)

    Franciscus, Leo C.; Maldonado, Jaime J.

    1989-01-01

    A study was made to evaluate potential improvement to a commercial supersonic transport by powering it with supersonic through-flow fan turbofan engines. A Mach 3.2 mission was considered. The three supersonic fan engines considered were designed to operate at bypass ratios of 0.25, 0.5, and 0.75 at supersonic cruise. For comparison a turbine bypass turbojet was included in the study. The engines were evaluated on the basis of aircraft takeoff gross weight with a payload of 250 passengers for a fixed range of 5000 N.MI. The installed specific fuel consumption of the supersonic fan engines was 7 to 8 percent lower than that of the turbine bypass engine. The aircraft powered by the supersonic fan engines had takeoff gross weights 9 to 13 percent lower than aircraft powered by turbine bypass engines.

  16. Re-engining - The sound case for aircraft noise reduction

    NASA Astrophysics Data System (ADS)

    Goddard, K.

    1991-06-01

    The paper reviews the history of legislation to reduce jet-powered aircraft noise, particularly in the U.S.A. Recently introduced legislation is discussed and the paper goes on to explain the fundamental advantage of re-engining as a means of reducing aircraft noise. Th Rolls-Royce Tay engine is introduced and the two re-engine programs already launched are described. The expected large reductions in noise level which result from re-engining are illustrated. The paper concludes with a discussion on new programs, on the current airline business scene and on some aspects of the economics of re-engining.

  17. 14 CFR 21.128 - Tests: aircraft engines.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Tests: aircraft engines. 21.128 Section 21.128 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Production Under Type Certificate § 21.128 Tests:...

  18. 14 CFR 21.128 - Tests: aircraft engines.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Tests: aircraft engines. 21.128 Section 21.128 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Production Under Type Certificate § 21.128 Tests:...

  19. 14 CFR 21.128 - Tests: aircraft engines.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Tests: aircraft engines. 21.128 Section 21.128 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Production Under Type Certificate § 21.128 Tests:...

  20. 49 CFR 230.76 - Piston travel.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and...) Maximum piston travel. The maximum piston travel when steam locomotive is standing shall be as follows... Driving Wheel Brake 6 Engine Truck Brake 8 Tender Brake 9...

  1. 49 CFR 230.76 - Piston travel.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and...) Maximum piston travel. The maximum piston travel when steam locomotive is standing shall be as follows... Driving Wheel Brake 6 Engine Truck Brake 8 Tender Brake 9...

  2. 49 CFR 230.76 - Piston travel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and...) Maximum piston travel. The maximum piston travel when steam locomotive is standing shall be as follows... Driving Wheel Brake 6 Engine Truck Brake 8 Tender Brake 9...

  3. 49 CFR 230.76 - Piston travel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and...) Maximum piston travel. The maximum piston travel when steam locomotive is standing shall be as follows... Driving Wheel Brake 6 Engine Truck Brake 8 Tender Brake 9...

  4. 49 CFR 230.76 - Piston travel.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and...) Maximum piston travel. The maximum piston travel when steam locomotive is standing shall be as follows... Driving Wheel Brake 6 Engine Truck Brake 8 Tender Brake 9...

  5. 76 FR 68636 - Airworthiness Directives; Thielert Aircraft Engines GmbH (TAE) Reciprocating Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-07

    ...-01] RIN 2120-AA64 Airworthiness Directives; Thielert Aircraft Engines GmbH (TAE) Reciprocating Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule; request for comments. SUMMARY: We are superseding an existing airworthiness directive (AD) for Thielert Aircraft Engines...

  6. Flutter of aircraft engine turbine blades

    NASA Astrophysics Data System (ADS)

    Panovsky, Josef, Jr.

    1997-11-01

    The goal of this research is to eliminate occurrences of flutter of low-pressure turbine blades in aircraft engines. Fundamental unsteady aerodynamic experiments in an annular cascade plus correlating analyses are conducted to improve the understanding of the flutter mechanism in these blades and to identify the key flutter parameters. The use of two- and three-dimensional linearized Euler methods for the calculation of the unsteady pressures due to the blade motion are validated through detailed comparison with the experimental data. Unexpected features of the steady and unsteady flows are also investigated using these computational tools. The validated computer codes are used to extend the range of the experimental data in a series of parametric studies, where the influence of mode shape, reduced frequency, and blade loading are investigated. Mode shape is identified as the most important contributor to determining the stability of a blade design. A new stability parameter is introduced to gain additional insight into the key contributors to flutter. This stability parameter is derived from the influence coefficient representation of the cascade, and includes only contributions from the reference blade and its immediate neighbors. This has the effect of retaining the most important contributions while filtering out terms of less significance. Design rules for the preliminary concept phase and procedures for the detailed analysis phase of the typical blade design process are defined. Utilization of these procedures will lead to blade designs which are free of flutter.

  7. Aircraft Engine Sump Fire Mitigation, Phase 2

    NASA Technical Reports Server (NTRS)

    Rosenlieb, J. W.

    1978-01-01

    The effect of changes in the input parameters (air leakage flow rate and temperature and lubricating oil inlet flow rate and temperature) over a specified range on the flammability conditions within an aircraft engine bearing sump was investigated. An analytical study was performed to determine the effect of various parameters on the generation rate of oil vapor from oil droplets in a hot air stream flowing in a cylindrical tube. The ignition of the vapor-air mixture by an ignition source was considered. The experimental investigation demonstrated that fires would be ignited by a spark ignitor over the full range of air and oil flow rates and air temperatures evaluated. However, no fires could be ignited when the oil inlet temperature was maintained below 41.7 K (290 F). The severity of the fires ignited were found to be directly proportional to the hot air flow rate. Reasonably good correlation was found between the mixture temperature in the sump at the ignitor location and the flammability limits as defined by flammability theory; thus a fairly reliable experimental method of determining flammable conditions within a sump was demonstrated. The computerized mathematical model shows that oil droplet size and air temperature have the greatest influence on the generation rate of oil vapor.

  8. Calculation of odour emissions from aircraft engines at Copenhagen Airport.

    PubMed

    Winther, Morten; Kousgaard, Uffe; Oxbøl, Arne

    2006-07-31

    In a new approach the odour emissions from aircraft engines at Copenhagen Airport are calculated using actual fuel flow and emission measurements (one main engine and one APU: Auxiliary Power Unit), odour panel results, engine specific data and aircraft operational data for seven busy days. The calculation principle assumes a linear relation between odour and HC emissions. Using a digitalisation of the aircraft movements in the airport area, the results are depicted on grid maps, clearly reflecting aircraft operational statistics as single flights or total activity during a whole day. The results clearly reflect the short-term temporal fluctuations of the emissions of odour (and exhaust gases). Aircraft operating at low engine thrust (taxiing, queuing and landing) have a total odour emission share of almost 98%, whereas the shares for the take off/climb out phases (2%) and APU usage (0.5%) are only marginal. In most hours of the day, the largest odour emissions occur, when the total amount of fuel burned during idle is high. However, significantly higher HC emissions for one specific engine cause considerable amounts of odour emissions during limited time periods. The experimentally derived odour emission factor of 57 OU/mg HC is within the range of 23 and 110 OU/mg HC used in other airport odour studies. The distribution of odour emission results between aircraft operational phases also correspond very well with the results for these other studies. The present study uses measurement data for a representative engine. However, the uncertainties become large when the experimental data is used to estimate the odour emissions for all aircraft engines. More experimental data is needed to increase inventory accuracy, and in terms of completeness it is recommended to make odour emission estimates also for engine start and the fuelling of aircraft at Copenhagen Airport in the future.

  9. Overview of NASA Lewis Research Center free-piston Stirling engine technology activities applicable to space power systems

    NASA Technical Reports Server (NTRS)

    Slaby, J. G.

    1986-01-01

    Free piston Stirling technology is applicable for both solar and nuclear powered systems. As such, the Lewis Research Center serves as the project office to manage the newly initiated SP-100 Advanced Technology Program. This five year program provides the technology push for providing significant component and subsystem options for increased efficiency, reliability and survivability, and power output growth at reduced specific mass. One of the major elements of the program is the development of advanced power conversion concepts of which the Stirling cycle is a viable candidate. Under this program the research findings of the 25 kWe opposed piston Space Power Demonstrator Engine (SPDE) are presented. Included in the SPDE discussions are initial differences between predicted and experimental power outputs and power output influenced by variations in regenerators. Projections are made for future space power requirements over the next few decades. And a cursory comparison is presented showing the mass benefits that a Stirling system has over a Brayton system for the same peak temperature and output power.

  10. Fiber-Optic Circuits For Aircraft Engine Controls

    NASA Astrophysics Data System (ADS)

    Glomb, Walter L.

    1987-12-01

    This paper describes environmental effects which impact the design of interfaces to fiber-optic sensors and data buses in aircraft engine controls. Emphasis is placed on selection of components and designs which maintain their performance and reliability in the harsh environment of an electronics enclosure mounted on a modern aircraft turbine engine. Particular attention is given to the effects of temperature on electro-optical component and system performance. The main conclusion is that electro-optical interfaces to a variety of fiber-optic systems can be installed in an engine-mounted control if the designs and components are selected after careful analysis of the effects of the engine environment.

  11. Pooled effect of injection pressure and turbulence inducer piston on performance, combustion, and emission characteristics of a DI diesel engine powered with biodiesel blend.

    PubMed

    Isaac JoshuaRamesh Lalvani, J; Parthasarathy, M; Dhinesh, B; Annamalai, K

    2016-12-01

    In this study, the effect of injection pressure on combustion, performance, and emission characteristics of a diesel engine powered with turbulence inducer piston was studied. Engine tests were executed using conventional diesel and 20% blend of adelfa biodiesel [A20]. The results acquired from renewable fuel A20 in the conventional engine showed reduction in brake thermal efficiency being the result of poor air fuel mixing characteristics and the higher viscosity of the tested fuel. This prompted further research aiming at the improvement of turbulence for better air fuel mixing by a novel turbulence inducer piston [TIP]. The investigation was carried out to study the combined effect of injection pressure and turbulence inducer piston. Considerable improvement in the emission characteristics like hydrocarbon, carbon monoxide, smoke was acheived as a result of optimised injection pressure. Nevertheless, the nitrogen oxide emissions were slightly higher than those of the conventional unmodified engine. The engine with turbulence inducer piston shows the scope for reducing the major pollution and thus ensures environmental safety.

  12. A Roadmap for Aircraft Engine Life Extending Control

    NASA Technical Reports Server (NTRS)

    Guo, Ten-Huei

    2001-01-01

    The concept of Aircraft Engine Life Extending Control is introduced. A brief description of the tradeoffs between performance and engine life are first explained. The overall goal of the life extending controller is to reduce the engine operating cost by extending the on-wing engine life while improving operational safety. The research results for NASA's Rocket Engine life extending control program are also briefly described. Major building blocks of the Engine Life Extending Control architecture are examined. These blocks include: life prediction models, engine operation models, stress and thermal analysis tools, control schemes, and intelligent control systems. The technology areas that would likely impact the successful implementation of an aircraft engine life extending control are also briefly described. Near, intermediate, and long term goals of NASA's activities are also presented.

  13. A conceptual study of the potential for automotive-derived and free-piston Stirling engines in 30- to 400-kilowatt stationary power applications

    NASA Technical Reports Server (NTRS)

    Vatsky, A.; Chen, H. S.; Dineen, J.

    1982-01-01

    The technical feasibility of applying automotive-derived kinematic and free-piston Stirling engine concepts for stationary applications was explored. Automotive-derived engines offer cost advantages by providing a mature and developd engine technology base with downrating and parts commonality options for specific applications. Two engine sizes (30 and 400 kW), two Stirling engine configurations (kinematic and free-piston), and two output systems (crankshaft and hydraulic pump) were studied. The study includes the influences of using either hydrogen or helium as the working gas. The first kinematic configuration selects an existing Stirling engine design from an automotive application and adapts it to stationary requirements. A 50,000-hour life requirement was established by downrating the engine to 40 kW and reducing auxiliary loads. Efficiency improvements were gained by selective material and geometric variations and peak brake efficiency of 36.8 percent using helium gas was achieved. The second design was a four-cylinder, 400 kW engine, utilizing a new output drive system known as the z-crank, which provides lower friction losses and variable stroke power control. Three different material and working gas combinations were considered. Brake efficiency levels varied from 40.5 percent to 45.6 percent. A 37.5 kW single-cycle, free-piston hydraulic output design was generated by scaling one cylinder of the original automotive engine and mating it to a counterbalanced reciprocal hydraulic pump. Metallic diaphragms were utilized to transmit power.

  14. Compression retaining piston

    SciTech Connect

    Quaglino, A.V. Jr.

    1987-06-16

    A piston apparatus is described for maintaining compression between the piston wall and the cylinder wall, that comprises the following: a generally cylindrical piston body, including: a head portion defining the forward end of the body; and a continuous side wall portion extending rearward from the head portion; a means for lubricating and preventing compression loss between the side wall portion and the cylinder wall, including an annular recessed area in the continuous side wall portion for receiving a quantity of fluid lubricant in fluid engagement between the wall of the recessed and the wall of the cylinder; a first and second resilient, elastomeric, heat resistant rings positioned in grooves along the wall of the continuous side wall portion, above and below the annular recessed area. Each ring engages the cylinder wall to reduce loss of lubricant within the recessed area during operation of the piston; a first pump means for providing fluid lubricant to engine components other than the pistons; and a second pump means provides fluid lubricant to the recessed area in the continuous side wall portion of the piston. The first and second pump means obtains lubricant from a common source, and the second pump means including a flow line supplies oil from a predetermined level above the level of oil provided to the first pump means. This is so that should the oil level to the second pump means fall below the predetermined level, the loss of oil to the recessed area in the continuous side wall portion of the piston would result in loss of compression and shut down of the engine.

  15. 78 FR 70216 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-25

    ... Engines GmbH Reciprocating Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for all Thielert Aircraft Engines GmbH TAE 125-01 reciprocating engines. This AD requires applying sealant to close the engine clutch...

  16. Intelligent Life-Extending Controls for Aircraft Engines Studied

    NASA Technical Reports Server (NTRS)

    Guo, Ten-Huei

    2005-01-01

    Current aircraft engine controllers are designed and operated to provide desired performance and stability margins. Except for the hard limits for extreme conditions, engine controllers do not usually take engine component life into consideration during the controller design and operation. The end result is that aircraft pilots regularly operate engines under unnecessarily harsh conditions to strive for optimum performance. The NASA Glenn Research Center and its industrial and academic partners have been working together toward an intelligent control concept that will include engine life as part of the controller design criteria. This research includes the study of the relationship between control action and engine component life as well as the design of an intelligent control algorithm to provide proper tradeoffs between performance and engine life. This approach is expected to maintain operating safety while minimizing overall operating costs. In this study, the thermomechanical fatigue (TMF) of a critical component was selected to demonstrate how an intelligent engine control algorithm can significantly extend engine life with only a very small sacrifice in performance. An intelligent engine control scheme based on modifying the high-pressure spool speed (NH) was proposed to reduce TMF damage from ground idle to takeoff. The NH acceleration schedule was optimized to minimize the TMF damage for a given rise-time constraint, which represents the performance requirement. The intelligent engine control scheme was used to simulate a commercial short-haul aircraft engine.

  17. Lightweight, low compression aircraft diesel engine. [converting a spark ignition engine to the diesel cycle

    NASA Technical Reports Server (NTRS)

    Gaynor, T. L.; Bottrell, M. S.; Eagle, C. D.; Bachle, C. F.

    1977-01-01

    The feasibility of converting a spark ignition aircraft engine to the diesel cycle was investigated. Procedures necessary for converting a single cylinder GTS10-520 are described as well as a single cylinder diesel engine test program. The modification of the engine for the hot port cooling concept is discussed. A digital computer graphics simulation of a twin engine aircraft incorporating the diesel engine and Hot Fort concept is presented showing some potential gains in aircraft performance. Sample results of the computer program used in the simulation are included.

  18. Dynamic analysis of Free-Piston Stirling Engine/Linear Alternator-load system-experimentally validated

    NASA Technical Reports Server (NTRS)

    Kankam, M. David; Rauch, Jeffrey S.; Santiago, Walter

    1992-01-01

    This paper discusses the effects of variations in system parameters on the dynamic behavior of the Free-Piston Stirling Engine/Linear Alternator (FPSE/LA)-load system. The mathematical formulations incorporate both the mechanical and thermodynamic properties of the FPSE, as well as the electrical equations of the connected load. A state-space technique in the frequency domain is applied to the resulting system of equations to facilitate the evaluation of parametric impacts on the system dynamic stability. Also included is a discussion on the system transient stability as affected by sudden changes in some key operating conditions. Some representative results are correlated with experimental data to verify the model and analytic formulation accuracies. Guidelines are given for ranges of the system parameters which will ensure an overall stable operation.

  19. Integrated engine-generator for aircraft secondary power.

    NASA Technical Reports Server (NTRS)

    Secunde, R. R.

    1972-01-01

    The integrated engine-generator concept consists of an electric generator located inside a turbojet or turbofan engine and both concentric with and driven by one of the main engine shafts. The electric power-conversion equipment and generator controls are conveniently located in the aircraft. When properly rated, the generator serves as an engine starter as well as a source of electric power. The available generating capacity permits use of electrically driven engine accessories. This reduces or eliminates the need for an external gearbox on the engine, thereby simplifying the engine and nacelle assembly and increasing aircraft design flexibility. The nacelle diameter can then be decreased, resulting in less aerodynamic drag and reduced takeoff gross weight.

  20. Piston slap induced pressure fluctuation in the water coolant passage of an internal combustion engine

    NASA Astrophysics Data System (ADS)

    Ohta, Kazuhide; Wang, Xiaoyu; Saeki, Atsushi

    2016-02-01

    Liner cavitation is caused by water pressure fluctuation in the water coolant passage (WCP). When the negative pressure falls below the saturated vapor pressure, the impulsive pressure following the implosion of cavitation bubbles causes cavitation erosion of the wet cylinder liner surface. The present work establishes a numerical model for structural-acoustic coupling between the crankcase and the acoustic field in the WCP considering their dynamic characteristics. The coupling effect is evaluated through mutual interaction terms that are calculated from the mode shapes of the acoustic field and of the crankcase vibration on the boundary. Water pressure fluctuations in the WCP under the action of piston slap forces are predicted and the contributions of the uncoupled mode shapes of the crankcase and the acoustic field to the pressure waveform are analyzed. The influence of sound speed variations on the water pressure response is discussed, as well as the pressure on the thrust sides of the four cylinders.

  1. 76 FR 82110 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-30

    ...-30-AD; Amendment 39-16906; AD 2010-06-12R1] RIN 2120-AA64 Airworthiness Directives; Thielert Aircraft.... SUMMARY: We are revising an existing airworthiness directive (AD) for Thielert Aircraft Engines GmbH models TAE 125-02-99 and TAE 125-01 reciprocating engines. That AD currently requires replacing...

  2. Further studies of methods for reducing community noise around airports. [aircraft noise - aircraft engines

    NASA Technical Reports Server (NTRS)

    Petersen, R. H.; Barry, D. J.; Kline, D. M.

    1975-01-01

    A simplified method of analysis was used in which all flights at a 'simulated' airport were assumed to operate from one runway in a single direction. For this simulated airport, contours of noise exposure forecast were obtained and evaluated. A flight schedule of the simulated airport which is representative of the 23 major U. S. airports was used. The effect of banning night-time operations by four-engine, narrow-body aircraft in combination with other noise reduction options was studied. The reductions in noise which would occur of two- and three-engine, narrow-body aircraft equipped with a refanned engine was examined. A detailed comparison of the effects of engine cutback on takeoff versus the effects of retrofitting quiet nacelles for narrow-body aircraft was also examined. A method of presenting the effects of various noise reduction options was treated.

  3. Lifecycle Information of Aircraft Engine Components

    DTIC Science & Technology

    2010-04-14

    commercial aircraft, the industry generated a number of potential RFID-based applications for airlines, air- freight carriers, aircraft maintenance and...adoption of RFID technologies to track serially controlled items requires careful planning and design. Data overload and data noise also affect the...performance of RFID systems. Data overload results from continuously scanning the RFID tags within reader range and sending the repeated information

  4. 77 FR 58301 - Technical Amendment; Airworthiness Standards: Aircraft Engines; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... technical amendment, the FAA clarified aircraft engine vibration test requirements in the airworthiness... amendment, the FAA intended to clarify vibration test requirements in Sec. 33.83 of 14 Code of Federal... read as follows: Sec. 33.83 Vibration test. (a) Each engine must undergo vibration surveys to...

  5. Condensed data on the aircraft engines of the world

    NASA Technical Reports Server (NTRS)

    Fliedner, C S

    1929-01-01

    This compilation of the outstanding characteristics of the available aircraft engines of the world was prepared as a compact ready reference for desk use. It does not pretend to be anything but a skeleton outline of the characteristics of engines reported in the technical press as being in either the experimental, development, or production stage.

  6. Workshop on Aerosols and Particulates from Aircraft Gas Turbine Engines

    NASA Technical Reports Server (NTRS)

    Wey, Chown Chou (Compiler)

    1999-01-01

    In response to the National Research Council (NRC) recommendations, the Workshop on Aerosols and Particulates from Aircraft Gas Turbine Engines was organized by the NASA Lewis Research Center and held on July 29-30, 1997 at the Ohio Aerospace Institute in Cleveland, Ohio. The objective is to develop consensus among experts in the field of aerosols from gas turbine combustors and engines as to important issues and venues to be considered. Workshop participants' expertise included engine and aircraft design, combustion processes and kinetics, atmospheric science, fuels, and flight operations and instrumentation.

  7. The development of turbojet aircraft in Germany, Britain, and the United States: A multi-national comparison of aeronautical engineering, 1935--1946

    NASA Astrophysics Data System (ADS)

    Pavelec, Sterling Michael

    In the 1930s aeronautical engineering needed revision. A presumptive anomaly was envisaged as piston-engine aircraft flew higher and faster. Radical alternatives to piston engines were considered in the unending quest for speed. Concurrently, but unwittingly, two turbojet engine programs were undertaken in Europe. The air-breathing three-stage turbojet engine was based on previous turbine technology; the revolutionary idea was the gas turbine as a prime mover for aircraft. In Germany, Dr. Hans von Ohain was the first to complete a flight-worthy turbojet engine for aircraft. Installed in a Heinkel designed aircraft, the Germans began the jet age on 27 August 1939. The Germans led throughout the war and were the first to produce jet aircraft for combat operations. The principal limiting factor for the German jet program was a lack of reliable engines. The continuing myths that Hitler orders, too little fuel, or too few pilots hindered the program are false. In England, Frank Whittle, without substantial support, but with dogged determination, also developed a turbojet engine. The British came second in the jet race when the Whittle engine powered the Gloster Pioneer on 15 May 1941. The Whittle-Gloster relationship continued and produced the only Allied combat jet aircraft during the war, the Meteor, which was confined to Home Defense in Britain. The American turbojet program was built directly from the Whittle engine. General Electric copied the Whittle designs and Bell Aircraft was contracted to build the first American jet plane. The Americans began the jet age on 1 October 1942 with a lackluster performance from their first jet, the Airacomet. But the Americans forged ahead, and had numerous engine and airframe programs in development by the end of the war. But, the Germans did it right and did it first. Partly because of a predisposition towards excellent engineering and physics, partly out of necessity, the Germans were able to produce combat turbojet aircraft

  8. Control Design for a Generic Commercial Aircraft Engine

    NASA Technical Reports Server (NTRS)

    Csank, Jeffrey; May, Ryan D.

    2010-01-01

    This paper describes the control algorithms and control design process for a generic commercial aircraft engine simulation of a 40,000 lb thrust class, two spool, high bypass ratio turbofan engine. The aircraft engine is a complex nonlinear system designed to operate over an extreme range of environmental conditions, at temperatures from approximately -60 to 120+ F, and at altitudes from below sea level to 40,000 ft, posing multiple control design constraints. The objective of this paper is to provide the reader an overview of the control design process, design considerations, and justifications as to why the particular architecture and limits have been chosen. The controller architecture contains a gain-scheduled Proportional Integral controller along with logic to protect the aircraft engine from exceeding any limits. Simulation results illustrate that the closed loop system meets the Federal Aviation Administration s thrust response requirements

  9. QCGAT aircraft/engine design for reduced noise and emissions

    NASA Technical Reports Server (NTRS)

    Lanson, L.; Terrill, K. M.

    1980-01-01

    The high bypass ratio QCGAT engine played an important role in shaping the aircraft design. The aircraft which evolved is a sleek, advanced design, six-place aircraft with 3538 kg (7,800 lb) maximum gross weight. It offers a 2778 kilometer (1500 nautical mile) range with cruise speed of 0.5 Mach number and will take-off and land on the vast majority of general aviation airfields. Advanced features include broad application of composite materials and a supercritical wing design with winglets. Full-span fowler flaps were introduced to improve landing capability. Engines are fuselage-mounted with inlets over the wing to provide shielding of fan noise by the wing surfaces. The design objectives, noise, and emission considerations, engine cycle and engine description are discussed as well as specific design features.

  10. Performance Characteristics of an Aircraft Engine with Exhaust Turbine Supercharger

    DTIC Science & Technology

    1941-05-01

    installation of’the ex- haust turbine supercha~ger. The two piston rods at oppb- si t e ends of the s e r vo c~rl iuder ware connect a d to the aut 0... crankshaft through multispeed gears. INTRODUCTION It is the function of superchargers in general to aug- Dent the porforcance of an internal-combustion engine...to the arbitrary design limit of the turbine and blower combination, the unit should be capable of main- taining approximate12r sea-level operating

  11. Advanced diagnostic system for piston slap faults in IC engines, based on the non-stationary characteristics of the vibration signals

    NASA Astrophysics Data System (ADS)

    Chen, Jian; Randall, Robert Bond; Peeters, Bart

    2016-06-01

    Artificial Neural Networks (ANNs) have the potential to solve the problem of automated diagnostics of piston slap faults, but the critical issue for the successful application of ANN is the training of the network by a large amount of data in various engine conditions (different speed/load conditions in normal condition, and with different locations/levels of faults). On the other hand, the latest simulation technology provides a useful alternative in that the effect of clearance changes may readily be explored without recourse to cutting metal, in order to create enough training data for the ANNs. In this paper, based on some existing simplified models of piston slap, an advanced multi-body dynamic simulation software was used to simulate piston slap faults with different speeds/loads and clearance conditions. Meanwhile, the simulation models were validated and updated by a series of experiments. Three-stage network systems are proposed to diagnose piston faults: fault detection, fault localisation and fault severity identification. Multi Layer Perceptron (MLP) networks were used in the detection stage and severity/prognosis stage and a Probabilistic Neural Network (PNN) was used to identify which cylinder has faults. Finally, it was demonstrated that the networks trained purely on simulated data can efficiently detect piston slap faults in real tests and identify the location and severity of the faults as well.

  12. Aircraft stress sequence development: A complex engineering process made simple

    NASA Technical Reports Server (NTRS)

    Schrader, K. H.; Butts, D. G.; Sparks, W. A.

    1994-01-01

    Development of stress sequences for critical aircraft structure requires flight measured usage data, known aircraft loads, and established relationships between aircraft flight loads and structural stresses. Resulting cycle-by-cycle stress sequences can be directly usable for crack growth analysis and coupon spectra tests. Often, an expert in loads and spectra development manipulates the usage data into a typical sequence of representative flight conditions for which loads and stresses are calculated. For a fighter/trainer type aircraft, this effort is repeated many times for each of the fatigue critical locations (FCL) resulting in expenditure of numerous engineering hours. The Aircraft Stress Sequence Computer Program (ACSTRSEQ), developed by Southwest Research Institute under contract to San Antonio Air Logistics Center, presents a unique approach for making complex technical computations in a simple, easy to use method. The program is written in Microsoft Visual Basic for the Microsoft Windows environment.

  13. Rankline-Brayton engine powered solar thermal aircraft

    SciTech Connect

    Bennett, Charles L

    2012-03-13

    A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

  14. Rankine-Brayton engine powered solar thermal aircraft

    SciTech Connect

    Bennett, Charles L.

    2009-12-29

    A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

  15. Knowledge Gained from Practical Experience in the Designing of Aircraft Engines

    NASA Technical Reports Server (NTRS)

    Kurtz, Oskar

    1933-01-01

    The present report examines a few important points of engine design such as: in-line water cooled engines, air-cooled in-line engines, and air-cooled radial engines. Subassemblies are also discussed like cylinder types, blower driving gears, pistons, valves, bearings, and crankshafts.

  16. Conceptual design of single turbofan engine powered light aircraft

    NASA Technical Reports Server (NTRS)

    Snyder, F. S.; Voorhees, C. G.; Heinrich, A. M.; Baisden, D. N.

    1977-01-01

    The conceptual design of a four place single turbofan engine powered light aircraft was accomplished utilizing contemporary light aircraft conventional design techniques as a means of evaluating the NASA-Ames General Aviation Synthesis Program (GASP) as a preliminary design tool. In certain areas, disagreement or exclusion were found to exist between the results of the conventional design and GASP processes. Detail discussion of these points along with the associated contemporary design methodology are presented.

  17. Effects of Structural Flexibility on Aircraft-Engine Mounts

    NASA Technical Reports Server (NTRS)

    Phillips, W. H.

    1986-01-01

    Analysis extends technique for design of widely used type of vibration-isolating mounts for aircraft engines, in which rubber mounting pads located in plane behind center of gravity of enginepropeller combination. New analysis treats problem in statics. Results of simple approach useful in providing equations for design of vibrationisolating mounts. Equations applicable in usual situation in which engine-mount structure itself relatively light and placed between large mass of engine and other heavy components of airplane.

  18. Aircraft Turbine Engine Control Research at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay

    2014-01-01

    This lecture will provide an overview of the aircraft turbine engine control research at NASA (National Aeronautics and Space Administration) Glenn Research Center (GRC). A brief introduction to the engine control problem is first provided with a description of the current state-of-the-art control law structure. A historical aspect of engine control development since the 1940s is then provided with a special emphasis on the contributions of GRC. The traditional engine control problem has been to provide a means to safely transition the engine from one steady-state operating point to another based on the pilot throttle inputs. With the increased emphasis on aircraft safety, enhanced performance and affordability, and the need to reduce the environmental impact of aircraft, there are many new challenges being faced by the designers of aircraft propulsion systems. The Controls and Dynamics Branch (CDB) at GRC is leading and participating in various projects in partnership with other organizations within GRC and across NASA, other government agencies, the U.S. aerospace industry, and academia to develop advanced propulsion controls and diagnostics technologies that will help meet the challenging goals of NASA programs under the Aeronautics Research Mission. The second part of the lecture provides an overview of the various CDB technology development activities in aircraft engine control and diagnostics, both current and some accomplished in the recent past. The motivation for each of the research efforts, the research approach, technical challenges and the key progress to date are summarized. The technologies to be discussed include system level engine control concepts, gas path diagnostics, active component control, and distributed engine control architecture. The lecture will end with a futuristic perspective of how the various current technology developments will lead to an Intelligent and Autonomous Propulsion System requiring none to very minimum pilot interface

  19. Multi-fuel rotary engine for general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Jones, C.; Ellis, D. R.; Meng, P. R.

    1983-01-01

    Design studies of advanced multifuel general aviation and commuter aircraft rotary stratified charge engines are summarized. Conceptual design studies were performed at two levels of technology, on advanced general aviation engines sized to provide 186/250 shaft kW/hp under cruise conditions at 7620 (25000 m/ft) altitude. A follow on study extended the results to larger (2500 hp max.) engine sizes suitable for applications such as commuter transports and helicopters. The study engine designs were derived from relevant engine development background including both prior and recent engine test results using direct injected unthrottled rotary engine technology. Aircraft studies, using these resultant growth engines, define anticipated system effects of the performance and power density improvements for both single engine and twin engine airplanes. The calculated results indicate superior system performance and 27 to 33 percent fuel economy improvement for the rotary engine airplanes as compared to equivalent airframe concept designs with current baseline engines. The research and technology activities required to attain the projected engine performance levels are also discussed.

  20. The Aerothermodynamics of Aircraft Gas Turbine Engines

    DTIC Science & Technology

    1978-07-01

    line and staggered tube ~ anks . Another way to get the coolant out of the trailing edge is to use drilled holes. These are normally calculated using...Pittsburgh, PA, 1976. 20.35 Butze, H. F., and Ehlers , R. C., "Effect of FUel Properties on Performance of a Single Aircraft Turbojet Combustor," NASA-Tl~-X...20.75 Butze, H. F .. and Ehlers , R. C., "Effect of Fuel Properties on Performance of A Single Aircraft Turboj et Combustor," NASA-TM-X-71789

  1. 77 FR 13488 - Airworthiness Directives; Thielert Aircraft Engines GmbH (TAE) Reciprocating Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-07

    ... Engines GmbH (TAE) Reciprocating Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final... TAE 125-02-99 reciprocating engines installed on, but not limited to, Diamond Aircraft Industries...-E002801, on TAE 125-02-99 engine. This AD was prompted by TAE increasing the life of the PPRV, part...

  2. 78 FR 1733 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... Engines GmbH Reciprocating Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are superseding an existing airworthiness directive (AD) for all Thielert Aircraft Engines GmbH models TAE 125-01, TAE 125-02- 99, and TAE 125-02-114 reciprocating engines. That AD...

  3. 77 FR 4217 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-27

    ... Engines GmbH Reciprocating Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for all Thielert Aircraft Engines GmbH (TAE) ] TAE 125-02-99 and TAE 125-02-114 reciprocating engines. This AD was prompted by in-flight...

  4. 78 FR 1728 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... Engines GmbH Reciprocating Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for all Thielert Aircraft Engines GmbH (TAE) TAE 125-02-99 and TAE 125-02-114 reciprocating engines. This AD requires inspection of the oil...

  5. Aircraft Turbine Engine Control Research at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay

    2013-01-01

    This paper provides an overview of the aircraft turbine engine control research at the NASA Glenn Research Center (GRC). A brief introduction to the engine control problem is first provided with a description of the state-of-the-art control law structure. A historical aspect of engine control development since the 1940s is then provided with a special emphasis on the contributions of GRC. With the increased emphasis on aircraft safety, enhanced performance, and affordability, as well as the need to reduce the environmental impact of aircraft, there are many new challenges being faced by the designers of aircraft propulsion systems. The Controls and Dynamics Branch (CDB) at GRC is leading and participating in various projects to develop advanced propulsion controls and diagnostics technologies that will help meet the challenging goals of NASA Aeronautics Research Mission programs. The rest of the paper provides an overview of the various CDB technology development activities in aircraft engine control and diagnostics, both current and some accomplished in the recent past. The motivation for each of the research efforts, the research approach, technical challenges, and the key progress to date are summarized.

  6. 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.

  7. Some aspects of aircraft jet engine fuels

    NASA Technical Reports Server (NTRS)

    Bekiesinski, R.

    1979-01-01

    Technologies are reviewed for improving the thermal stability of jet fuels, with reference to the overheating of fuel tanks in supersonic aircraft. Consideration is given to the development of a jet fuel with high thermal stability by the Polish petroleum industry.

  8. Recent Progress in Engine Noise Reduction for Commercial Aircraft Applications

    NASA Technical Reports Server (NTRS)

    Huff, Dennis L.

    2003-01-01

    Considerable progress has been made over the past ten years developing technologies for reducing aircraft noise. Engine noise continues to be a dominate source, particularly for aircraft departing from airports. Research efforts have concentrated on developing noise prediction methods, experimental validation, and developing noise reduction concepts that have been verified through model scale and static engine tests. Most of the work has concentrated on fan and jet components for commercial turbofan engines. In this seminar, an overview of the engine noise reduction work that was sponsored by NASA s Advanced Subsonic Technology Noise Reduction Program will be given, along with background information on turbofan noise sources and certification procedures. Concepts like "chevron" nozzles for jet noise reduction and swept stators for fan noise reduction will be highlighted. A preliminary assessment on how the new technologies will impact future engines will be given.

  9. Characterization of chemical and particulate emissions from aircraft engines

    NASA Astrophysics Data System (ADS)

    Agrawal, Harshit; Sawant, Aniket A.; Jansen, Karel; Wayne Miller, J.; Cocker, David R.

    2008-06-01

    This paper presents a series of measurements from four on-wing, commercial aircraft engines, including two newer CFM56-7 engines and two earlier CFM56-3 engines. Samples were collected from each engine using a probe positioned behind the exhaust nozzle of the aircraft, chocked on a concrete testing pad. The emission factors for particulate matter mass, elemental and organic carbon, carbonyls, polycyclic aromatic hydrocarbons, n-alkanes, dioxins, metals and ions are reported for four different engine power setting modes. The emissions indices of particulate matter, elemental and organic carbon are highly power dependent for these engines. Particulate matter emission indices (g kg-1 fuel) are found to increase from 1.1E-02 to 2.05E-01 with increase in power from idle to 85%. The elemental carbon to organic carbon varies from 0.5 to 3.8 with change in power from idle to 85%. The carbonyl emissions are dominated by formaldehyde. The emission index of formaldehyde ranges from 2.3E-01 to 4.8E-01 g kg-1 fuel. The distribution of metals depends on the difference in the various engines. The dioxin emissions from the aircraft engines are observed to be below detection limit.

  10. Advanced control for airbreathing engines, volume 2: General Electric aircraft engines

    NASA Technical Reports Server (NTRS)

    Bansal, Indar

    1993-01-01

    The application of advanced control concepts to air breathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for air breathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 2 of these reports describes the studies performed by GE Aircraft Engines.

  11. Multi-Fuel Rotary Engine for General Aviation Aircraft

    NASA Technical Reports Server (NTRS)

    Jones, C.; Ellis, D. R.; Meng, P. R.

    1983-01-01

    Design studies, conducted for NASA, of Advanced Multi-fuel General Aviation and Commuter Aircraft Rotary Stratified Charge Engines are summarized. Conceptual design studies of an advanced engine sized to provide 186/250 shaft KW/HP under cruise conditions at 7620/25,000 m/ft. altitude were performed. Relevant engine development background covering both prior and recent engine test results of the direct injected unthrottled rotary engine technology, including the capability to interchangeably operate on gasoline, diesel fuel, kerosene, or aviation jet fuel, are presented and related to growth predictions. Aircraft studies, using these resultant growth engines, define anticipated system effects of the performance and power density improvements for both single engine and twin engine airplanes. The calculated results indicate superior system performance and 30 to 35% fuel economy improvement for the Rotary-engine airplanes as compared to equivalent airframe concept designs with current baseline engines. The research and technology activities required to attain the projected engine performance levels are also discussed.

  12. Adaptive Optimization of Aircraft Engine Performance Using Neural Networks

    NASA Technical Reports Server (NTRS)

    Simon, Donald L.; Long, Theresa W.

    1995-01-01

    Preliminary results are presented on the development of an adaptive neural network based control algorithm to enhance aircraft engine performance. This work builds upon a previous National Aeronautics and Space Administration (NASA) effort known as Performance Seeking Control (PSC). PSC is an adaptive control algorithm which contains a model of the aircraft's propulsion system which is updated on-line to match the operation of the aircraft's actual propulsion system. Information from the on-line model is used to adapt the control system during flight to allow optimal operation of the aircraft's propulsion system (inlet, engine, and nozzle) to improve aircraft engine performance without compromising reliability or operability. Performance Seeking Control has been shown to yield reductions in fuel flow, increases in thrust, and reductions in engine fan turbine inlet temperature. The neural network based adaptive control, like PSC, will contain a model of the propulsion system which will be used to calculate optimal control commands on-line. Hopes are that it will be able to provide some additional benefits above and beyond those of PSC. The PSC algorithm is computationally intensive, it is valid only at near steady-state flight conditions, and it has no way to adapt or learn on-line. These issues are being addressed in the development of the optimal neural controller. Specialized neural network processing hardware is being developed to run the software, the algorithm will be valid at steady-state and transient conditions, and will take advantage of the on-line learning capability of neural networks. Future plans include testing the neural network software and hardware prototype against an aircraft engine simulation. In this paper, the proposed neural network software and hardware is described and preliminary neural network training results are presented.

  13. Organic positive ions in aircraft gas-turbine engine exhaust

    NASA Astrophysics Data System (ADS)

    Sorokin, Andrey; Arnold, Frank

    Volatile organic compounds (VOCs) represent a significant fraction of atmospheric aerosol. However the role of organic species emitted by aircraft (as a consequence of the incomplete combustion of fuel in the engine) in nucleation of new volatile particles still remains rather speculative and requires a much more detailed analysis of the underlying mechanisms. Measurements in aircraft exhaust plumes have shown the presence of both different non-methane VOCs (e.g. PartEmis project) and numerous organic cluster ions (MPIK-Heidelberg). However the link between detected organic gas-phase species and measured mass spectrum of cluster ions is uncertain. Unfortunately, up to now there are no models describing the thermodynamics of the formation of primary organic cluster ions in the exhaust of aircraft engines. The aim of this work is to present first results of such a model development. The model includes the block of thermodynamic data based on proton affinities and gas basicities of organic molecules and the block of non-equilibrium kinetics of the cluster ions evolution in the exhaust. The model predicts important features of the measured spectrum of positive ions in the exhaust behind aircraft. It is shown that positive ions emitted by aircraft engines into the atmosphere mostly consist of protonated and hydrated organic cluster ions. The developed model may be explored also in aerosol investigations of the background atmosphere as well as in the analysis of the emission of fine aerosol particles by automobiles.

  14. Research on hypersonic aircraft using pre-cooled turbojet engines

    NASA Astrophysics Data System (ADS)

    Taguchi, Hideyuki; Kobayashi, Hiroaki; Kojima, Takayuki; Ueno, Atsushi; Imamura, Shunsuke; Hongoh, Motoyuki; Harada, Kenya

    2012-04-01

    Systems analysis of a Mach 5 class hypersonic aircraft is performed. The aircraft can fly across the Pacific Ocean in 2 h. A multidisciplinary optimization program for aerodynamics, structure, propulsion, and trajectory is used in the analysis. The result of each element model is improved using higher accuracy analysis tools. The aerodynamic performance of the hypersonic aircraft is examined through hypersonic wind tunnel tests. A thermal management system based on the data of the wind tunnel tests is proposed. A pre-cooled turbojet engine is adopted as the propulsion system for the hypersonic aircraft. The engine can be operated continuously from take-off to Mach 5. This engine uses a pre-cooling cycle using cryogenic liquid hydrogen. The high temperature inlet air of hypersonic flight would be cooled by the same liquid hydrogen used as fuel. The engine is tested under sea level static conditions. The engine is installed on a flight test vehicle. Both liquid hydrogen fuel and gaseous hydrogen fuel are supplied to the engine from a tank and cylinders installed within the vehicle. The designed operation of major components of the engine is confirmed. A large amount of liquid hydrogen is supplied to the pre-cooler in order to make its performance sufficient for Mach 5 flight. Thus, fuel rich combustion is adopted at the afterburner. The experiments are carried out under the conditions that the engine is mounted upon an experimental airframe with both set up either horizontally or vertically. As a result, the operating procedure of the pre-cooled turbojet engine is demonstrated.

  15. Application of automobile emission control technology to light piston aircraft engines

    NASA Technical Reports Server (NTRS)

    Tripp, D.; Kittredge, G.

    1976-01-01

    The possibility was evaluated for achieving the EPA Standards for HC and CO emissions through the use of air-fuel ratio enleanment at selected power modes combined with improved air-fuel mixture preparation, and in some cases improved cooling. Air injection was also an effective approach for the reduction of HC and CO, particularly when combined with exhaust heat conservation techniques such as exhaust port liners.

  16. Light Aircraft Piston Engine Carburetor Ice Detector/Warning Device Sensitivity/Effectiveness.

    DTIC Science & Technology

    1982-06-01

    2 RF5B 1 0 0 0 0 1 SA26 0 0 0 0 1 1 SCOOTER 0 0 1 0 0 1 SPORTS TERK 1 0 1 0 0 2 STITSSALLA 0 0 0 0 1 1 ST3KR 0 1 0 0 0 1 TC45B 0 0 1 0 0 1 UH12D 0 1 0...and the wdter solubility characteristics of tre fuel. hntrained water will freeze in cril fuel and tend to stay in suspension longer since the...specific gravity of ice is approximately the same as that of aviation gasoline. c. Water in suspension may freeze and form ice crystals of sufficient size

  17. A Systems Engineering Approach to Aircraft Kinetic Kill Countermeasures Technology: Development of an Active Aircraft Defense System for the C/KC-135 Aircraft. Volume 1

    DTIC Science & Technology

    1995-12-01

    AFIT/GSE/ENY/95D-01 A SYSTEMS ENGINEERING APPROACH TO AIRCRAFT KINETIC KILL COUNTERMEASURE TECHNOLOGY: DEVELOPMENT OF AN ACTIVE AIR DEFENSE SYSTEM...AFIT/GSE/ENY/95D-01 A SYSTEMS ENGINEERING APPROACH TO AIRCRAFT KINETIC KILL COUNTERMEASURE TECHNOLOGY: DEVELOPMENT OF AN ACTIVE AIR DEFENSE SYSTEM FOR...THE C/KC-135 AIRCRAFT THESIS (1 of2) Presented to the Faculty of the Graduate School of Engineering of the Air Force Institute of Technology Air

  18. Review of the Rhein-Flugzeugbau Wankel powered aircraft program. [ducted fan engines

    NASA Technical Reports Server (NTRS)

    Riethmueller, M.

    1978-01-01

    The development of light aircraft with special emphasis on modern propulsion systems and production is discussed in terms of the application of rotary engines to aircraft. Emphasis is placed on the integrated ducted-fan propulsion system using rotary engines.

  19. NO(x) reduction additives for aircraft gas turbine engines

    NASA Technical Reports Server (NTRS)

    Adelman, Henry G.; Menees, Gene P.; Cambier, Jean-Luc

    1993-01-01

    The reduction of oxides of nitrogen (NO(x)) emissions from aircraft gas turbine engines is a vital part of the NASA High Speed Research Program. Emissions reductions are critical to the feasibility of future High Speed Civil Transports which operate at supersonic speeds in the stratosphere. It is believed that large fleets of such aircraft using conventional gas turbine engines would emit levels of NO(x) that would be harmful to the stratospheric ozone layer. Previous studies have shown that NO(x) emissions can be reduced from stationary powerplant exhausts by the addition of additives such as ammonia to the exhaust gases. Since the exhaust residence times, pressures and temperatures may be different for aircraft gas turbines, a study has been made of additive effectiveness for high speed, high altitude flight.

  20. Fundamental Investigation of Jet Fuel Spray and Ignition Process in an Optically Accessible Piston Engine

    DTIC Science & Technology

    2015-01-16

    design of Almy engines. Tests were perf01med using #2 diesel fuel, jet fuel (JP8), and a hydroprocessed renewable jet fuel (HRJ). Ambient the1modynamic...1+~ .,:-•. ~-~ ~~~~·~~· · -~ ~- --~~ 1S. SUBJECT TERMS Transient, diesel , injection, optical engine 16. SECURITY...Tests were performed using #2 diesel fuel, jet fuel (JP8), and a hydroprocessed renewable jet fuel (HRJ). Ambient thermodynamic conditions and fuel

  1. Energy efficient engine flight propulsion system: Aircraft/engine integration evaluation

    NASA Technical Reports Server (NTRS)

    Patt, R. F.

    1980-01-01

    Results of aircraft/engine integration studies conducted on an advanced flight propulsion system are reported. Economic evaluations of the preliminary design are included and indicate that program goals will be met. Installed sfc, DOC, noise, and emissions were evaluated. Aircraft installation considerations and growth were reviewed.

  2. Energy efficient engine flight propulsion system: Aircraft/engine integration evaluation

    SciTech Connect

    Patt, R.F.

    1980-06-01

    Results of aircraft/engine integration studies conducted on an advanced flight propulsion system are reported. Economic evaluations of the preliminary design are included and indicate that program goals will be met. Installed sfc, DOC, noise, and emissions were evaluated. Aircraft installation considerations and growth were reviewed.

  3. Calculation of the pressures on aircraft engine bearings

    NASA Technical Reports Server (NTRS)

    Steigenberger, O

    1929-01-01

    For aircraft engines the three principal operating conditions are idling speed, cruising speed, and diving with the engine stopped. In what follows, we will discuss a method which affords a good idea of the course of pressure for the above mentioned operating conditions. The pressures produced in the driving gear are of three kinds; namely, the pressure due to gases, the pressure due to the inertia of the rotating masses, and the pressure due to the inertia of the reciprocating masses.

  4. Combustion system CFD modeling at GE Aircraft Engines

    NASA Technical Reports Server (NTRS)

    Burrus, D.; Mongia, H.; Tolpadi, Anil K.; Correa, S.; Braaten, M.

    1995-01-01

    This viewgraph presentation discusses key features of current combustion system CFD modeling capabilities at GE Aircraft Engines provided by the CONCERT code; CONCERT development history; modeling applied for designing engine combustion systems; modeling applied to improve fundamental understanding; CONCERT3D results for current production combustors; CONCERT3D model of NASA/GE E3 combustor; HYBRID CONCERT CFD/Monte-Carlo modeling approach; and future modeling directions.

  5. Optimal Discrete Event Supervisory Control of Aircraft Gas Turbine Engines

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan (Technical Monitor); Ray, Asok

    2004-01-01

    This report presents an application of the recently developed theory of optimal Discrete Event Supervisory (DES) control that is based on a signed real measure of regular languages. The DES control techniques are validated on an aircraft gas turbine engine simulation test bed. The test bed is implemented on a networked computer system in which two computers operate in the client-server mode. Several DES controllers have been tested for engine performance and reliability.

  6. Energy efficient engine: Propulsion system-aircraft integration evaluation

    NASA Technical Reports Server (NTRS)

    Owens, R. E.

    1979-01-01

    Flight performance and operating economics of future commercial transports utilizing the energy efficient engine were assessed as well as the probability of meeting NASA's goals for TSFC, DOC, noise, and emissions. Results of the initial propulsion systems aircraft integration evaluation presented include estimates of engine performance, predictions of fuel burns, operating costs of the flight propulsion system installed in seven selected advanced study commercial transports, estimates of noise and emissions, considerations of thrust growth, and the achievement-probability analysis.

  7. Advanced materials research for long-haul aircraft turbine engines

    NASA Technical Reports Server (NTRS)

    Signorelli, R. A.; Blankenship, C. P.

    1978-01-01

    The status of research efforts to apply low to intermediate temperature composite materials and advanced high temperature materials to engine components is reviewed. Emerging materials technologies and their potential benefits to aircraft gas turbines were emphasized. The problems were identified, and the general state of the technology for near term use was assessed.

  8. The Power of Aircraft Engines at Altitude

    NASA Technical Reports Server (NTRS)

    Ragazzi, Paolo

    1939-01-01

    The subject of the present paper is confined to the investigations and methods employed by the Fiat company in their studies on the altitude performance of an air-cooled engine of the production type. The experimental set-up as well as test engine data are provided.

  9. Heat exchanger design for hot air ericsson-brayton piston engine

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  10. HEAT exchanger design for hot air Ericsson-Brayton piston engine

    NASA Astrophysics Data System (ADS)

    Ďurčanský, Peter; Lenhard, Richard; Jandačka, Jozef

    2013-10-01

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

  11. Swirling-flow jet noise suppressors for aircraft engines

    NASA Technical Reports Server (NTRS)

    Schwartz, I. R.

    1976-01-01

    Experimental investigations of the effects of swirling the jet exhausts of small turbofan and turbojet engines have indicated significant progress towards predicting and attaining substantial jet noise abatement with minimum thrust losses in large aircraft engines. Systematic variations of the important swirl vane and swirling flow parameters were conducted to determine their effects on jet noise reduction and engine performance. Since swirling flow becomes more effective in reducing jet noise as the density and temperature gradients increase, the significant trends in noise reduction and engine performance that were established by these parametric studies could be projected into potentially greater reductions of sound pressure levels with minimum thrust losses by controlled swirling of the jets of high thrust engines. The density and temperature gradients in the jet exhausts of high thrust engines are larger by comparison with gradients in small engines.

  12. Stratified charge rotary aircraft engine technology enablement program

    NASA Technical Reports Server (NTRS)

    Badgley, P. R.; Irion, C. E.; Myers, D. M.

    1985-01-01

    The multifuel stratified charge rotary engine is discussed. A single rotor, 0.7L/40 cu in displacement, research rig engine was tested. The research rig engine was designed for operation at high speeds and pressures, combustion chamber peak pressure providing margin for speed and load excursions above the design requirement for a high is advanced aircraft engine. It is indicated that the single rotor research rig engine is capable of meeting the established design requirements of 120 kW, 8,000 RPM, 1,379 KPA BMEP. The research rig engine, when fully developed, will be a valuable tool for investigating, advanced and highly advanced technology components, and provide an understanding of the stratified charge rotary engine combustion process.

  13. Study of advanced rotary combustion engines for commuter aircraft

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  14. A 150 and 300 kW lightweight diesel aircraft engine design study

    NASA Technical Reports Server (NTRS)

    Brouwers, A. P.

    1980-01-01

    The diesel engine was reinvestigated as an aircraft powerplant through design study conducted to arrive at engine configurations and applicable advanced technologies. Two engines are discussed, a 300 kW six-cylinder engine for twin engine general aviation aircraft and a 150 kW four-cylinder engine for single engine aircraft. Descriptions of each engine include concept drawings, a performance analysis, stress and weight data, and a cost study. This information was used to develop two airplane concepts, a six-place twin and a four-place single engine aircraft. The aircraft study consists of installation drawings, computer generated performance data, aircraft operating costs, and drawings of the resulting airplanes. The performance data show a vast improvement over current gasoline-powered aircraft.

  15. SPRE I Free-Piston Stirling Engine Testing at NASA Lewis Research Center

    SciTech Connect

    Cairelli, J.E.

    1994-09-01

    As part of the NASA funded portion of the SP-100 Advanced Technology Program the Space Power Research Engine (SPRE I) was designed and built to serve as a research tool for evaluation and development of advanced Stirling engine concepts. The SPRE I is designed to produce 12.5 kW electrical power when operated with helium at 15 MPa and with an absolute temperature ratio of two. The engine is now under test in a new test facility which was designed and built at NASA LeRC specifically to test the SPRE I. This paper describes the SPRE I, the NASA test facility, the initial SPRE I test results, and future SPRE I test plans.

  16. Modeling a VR-type piston engine as the power plant

    NASA Astrophysics Data System (ADS)

    Gorshkalev, A. A.; Kayukov, S. S.; Korneev, S. S.; Urlapkin, V. V.

    2017-02-01

    This article describes existing methods of internal combustion engine calculation. The developed algorithm of diesel engine modeling in ‘AVL FIRE ESE DIESEL’ and ‘LMS Imagine.Lab AMESim’ software is presented. The algorithm includes description of model preparation, boundary condition setting and calculation execution. Obtained results of the modeling show significant enhancement in accuracy in contrast with analytical calculation. The difference between results obtained in different software is caused by a simplified combustion model in ‘LMS Imagine.Lab AMESim’ and a lack of a submodel describing a refrigeration system.

  17. Aircraft Turbine Engine Reliability and Inspection Investigations

    DTIC Science & Technology

    1993-10-01

    controls and accessories typically produced the largest number of in-flight flameouts, compressor stalls , and engine shutdowns. In addition to the actuarial...typically produced the largest number of in-flight flameouts, compressor stalls , and engine shutdowns. Diagnostic troubleshooting procedures for controls...airfoils suffer because these * materials are damaged during compressor stalls when cooling air flows are disrupted. 3. Fuel/oil system failures are

  18. Census U.S. Civil Aircraft Calendar Year 1993

    DTIC Science & Technology

    1993-12-31

    Turbojet 1.020 Helicopter 1,977 Total 10,692 2-3 TABLE 2.2 AIRCRAFT REPORTED IN OPERATION BY AIR CARRIERS, BY MANUFACTURER AND MODEL 1984-1993 Aircraft...2 41 1 0 146 146 A-49 U.S. REGISTERED CIVIL AIRCRAFT BY MANUFACTURER AND MODEL -NUMBER OF SEATS PISTON AS OF DECEMBER 31, 1993...AS OF DECEMBER 31, 1993 Total General TotalEngine Make Engine Model Engine Power Engines Air Carrier Aviation Aircraft ROLL-ROYCE ........... GRIFFON

  19. Cabin Noise Control for Twin Engine General Aviation Aircraft

    NASA Technical Reports Server (NTRS)

    Vaicaitis, R.; Slazak, M.

    1982-01-01

    An analytical model based on modal analysis was developed to predict the noise transmission into a twin-engine light aircraft. The model was applied to optimize the interior noise to an A-weighted level of 85 dBA. To achieve the required noise attenuation, add-on treatments in the form of honeycomb panels, damping tapes, acoustic blankets, septum barriers and limp trim panels were added to the existing structure. The added weight of the noise control treatment is about 1.1 percent of the total gross take-off weight of the aircraft.

  20. 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.

  1. Characterization of lubrication oil emissions from aircraft engines.

    PubMed

    Yu, Zhenhong; Liscinsky, David S; Winstead, Edward L; True, Bruce S; Timko, Michael T; Bhargava, Anuj; Herndon, Scott C; Miake-Lye, Richard C; Anderson, Bruce E

    2010-12-15

    In this first ever study, particulate matter (PM) emitted from the lubrication system overboard breather vent for two different models of aircraft engines has been systematically characterized. Lubrication oil was confirmed as the predominant component of the emitted particulate matter based upon the characteristic mass spectrum of the pure oil. Total particulate mass and size distributions of the emitted oil are also investigated by several high-sensitivity aerosol characterization instruments. The emission index (EI) of lubrication oil at engine idle is in the range of 2-12 mg kg(-1) and increases with engine power. The chemical composition of the oil droplets is essentially independent of engine thrust, suggesting that engine oil does not undergo thermally driven chemical transformations during the ∼4 h test window. Volumetric mean diameter is around 250-350 nm for all engine power conditions with a slight power dependence.

  2. Aircraft

    DOEpatents

    Hibbs, B.D.; Lissaman, P.B.S.; Morgan, W.R.; Radkey, R.L.

    1998-09-22

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing`s top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gases for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well. 31 figs.

  3. Aircraft

    DOEpatents

    Hibbs, Bart D.; Lissaman, Peter B. S.; Morgan, Walter R.; Radkey, Robert L.

    1998-01-01

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gasses for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well.

  4. Liquid lubricants for advanced aircraft engines

    NASA Technical Reports Server (NTRS)

    Loomis, William R.; Fusaro, Robert L.

    1992-01-01

    An overview of liquid lubricants for use in current and projected high performance turbojet engines is discussed. Chemical and physical properties are reviewed with special emphasis placed on the oxidation and thermal stability requirements imposed upon the lubrication system. A brief history is given of the development of turbine engine lubricants which led to the present day synthetic oils with their inherent modification advantages. The status and state of development of some eleven candidate classes of fluids for use in advanced turbine engines are discussed. Published examples of fundamental studies to obtain a better understanding of the chemistry involved in fluid degradation are reviewed. Alternatives to high temperature fluid development are described. The importance of continuing work on improving current high temperature lubricant candidates and encouraging development of new and improved fluid base stocks are discussed.

  5. Liquid lubricants for advanced aircraft engines

    SciTech Connect

    Loomis, W.R.; Fusaro, R.L.

    1992-08-01

    An overview of liquid lubricants for use in current and projected high performance turbojet engines is discussed. Chemical and physical properties are reviewed with special emphasis placed on the oxidation and thermal stability requirements imposed upon the lubrication system. A brief history is given of the development of turbine engine lubricants which led to the present day synthetic oils with their inherent modification advantages. The status and state of development of some eleven candidate classes of fluids for use in advanced turbine engines are discussed. Published examples of fundamental studies to obtain a better understanding of the chemistry involved in fluid degradation are reviewed. Alternatives to high temperature fluid development are described. The importance of continuing work on improving current high temperature lubricant candidates and encouraging development of new and improved fluid base stocks are discussed.

  6. Liquid lubricants for advanced aircraft engines

    NASA Technical Reports Server (NTRS)

    Loomis, William R.; Fusaro, Robert L.

    1993-01-01

    An overview of liquid lubricants for use in current and projected high performance turbojet engines is discussed. Chemical and physical properties are reviewed with special emphasis placed on the oxidation and thermal stability requirements imposed upon the lubrication system. A brief history is given of the development of turbine engine lubricants which led to the present day synthetic oils with their inherent modification advantages. The status and state of development of some eleven candidate classes of fluids for use in advanced turbine engines are discussed. Published examples of fundamental studies to obtain a better understanding of the chemistry involved in fluid degradation are reviewed. Alternatives to high temperature fluid development are described. The importance of continuing work on improving current high temperature lubricant candidates and encouraging development of new and improved fluid base stocks are discussed.

  7. Influence of sliding surface roughness and oil temperature on piston ring pack operation of an automotive IC engine

    NASA Astrophysics Data System (ADS)

    Wolff, A.

    2016-09-01

    In the paper a comprehensive model of a piston ring pack motion on an oil film has been presented. The local oil film thickness can be compared to height of the combined roughness of sliding surfaces of piston rings and cylinder liner. Equations describing the mixed lubrication problem based on the empirical mathematical model formulated in works of Patir, Cheng and Greenwood, Tripp have been combined and used in this paper. The developed model takes the following phenomena into account: hydrodynamic and contact forces, spring and gas forces acting on piston rings. The rings motion concerning low and high temperature of cylinder surface has been compared. These results concern cases of hydrodynamic and mixed lubrication. Changes of oil wetted area and contact zone of piston rings have been shown. In addition the oil film thickness distribution along cylinder liner and all the forces acting on piston rings have been analysed and discussed. The results have been presented in form of relevant diagrams. The developed model and software can be utilized for optimization of piston rings design.

  8. Lightweight diesel aircraft engines for general aviation

    NASA Technical Reports Server (NTRS)

    Berenyi, S. G.

    1983-01-01

    Two different engines were studied. The advantages of a diesel to general aviation were reduced to fuel consumption, reduced operating costs, and reduced fire and explosion hazard. There were no ignition mixture control or inlet icing problems. There are fewer controls and no electrical interference problems.

  9. Effectiveness of combined aircraft engine noise suppressors

    NASA Astrophysics Data System (ADS)

    Khaletskiy, Yu. D.

    2012-07-01

    We consider the design features of fan noise suppressors in application to air intakes and the bypass duct of a turbofan engine. A combined liner is developed that has increased acoustic efficiency in comparison to conventional honeycomb liner. We demonstrate the important role of the area of the sound-absorbing liner between fan Rotor and Stator ensuring significant noise reduction.

  10. Engine Conceptual Design Studies for a Hybrid Wing Body Aircraft

    NASA Technical Reports Server (NTRS)

    Tong, Michael T.; Jones, Scott M.; Haller, William J.; Handschuh, Robert F.

    2009-01-01

    Worldwide concerns of air quality and climate change have made environmental protection one of the most critical issues in aviation today. NASA's current Fundamental Aeronautics research program is directed at three generations of aircraft in the near, mid and far term, with initial operating capability around 2015, 2020, and 2030, respectively. Each generation has associated goals for fuel burn, NOx, noise, and field-length reductions relative to today's aircrafts. The research for the 2020 generation is directed at enabling a hybrid wing body (HWB) aircraft to meet NASA's aggressive technology goals. This paper presents the conceptual cycle and mechanical designs of the two engine concepts, podded and embedded systems, which were proposed for a HWB cargo freighter. They are expected to offer significant benefits in noise reductions without compromising the fuel burn.

  11. NASA Glenn's Contributions to Aircraft Engine Noise Research

    NASA Technical Reports Server (NTRS)

    Huff, Dennis L.

    2013-01-01

    This report reviews all engine noise research conducted at the NASA Glenn Research Center over the past 70 years. This report includes a historical perspective of the Center and the facilities used to conduct the research. Major noise research programs are highlighted to show their impact on industry and on the development of aircraft noise reduction technology. Noise reduction trends are discussed, and future aircraft concepts are presented. Since the 1960s, research results show that the average perceived noise level has been reduced by about 20 decibels (dB). Studies also show that, depending on the size of the airport, the aircraft fleet mix, and the actual growth in air travel, another 15 to 17 dB reduction will be required to achieve NASA's long-term goal of providing technologies to limit objectionable noise to the boundaries of an average airport.

  12. NASA Glenn's Contributions to Aircraft Engine Noise Research

    NASA Technical Reports Server (NTRS)

    Huff, Dennis L.

    2014-01-01

    This presentation reviews engine noise research conducted at the NASA Glenn Research Center over the past 70 years. This report includes a historical perspective of the Center and the facilities used to conduct the research. Major noise research programs are highlighted to show their impact on industry and on the development of aircraft noise reduction technology. Noise reduction trends are discussed, and future aircraft concepts are presented. Since the 1960s, research results show that the average perceived noise level has been reduced by about 20 decibels (dB). Studies also show that, depending on the size of the airport, the aircraft fleet mix, and the actual growth in air travel, another 15 to 17 dB reduction will be required to achieve NASAs long-term goal of providing technologies to limit objectionable noise to the boundaries of an average airport.

  13. Aircraft Engine Technology for Green Aviation to Reduce Fuel Burn

    NASA Technical Reports Server (NTRS)

    Hughes, Christopher E.; VanZante, Dale E.; Heidmann, James D.

    2013-01-01

    The NASA Fundamental Aeronautics Program Subsonic Fixed Wing Project and Integrated Systems Research Program Environmentally Responsible Aviation Project in the Aeronautics Research Mission Directorate are conducting research on advanced aircraft technology to address the environmental goals of reducing fuel burn, noise and NOx emissions for aircraft in 2020 and beyond. Both Projects, in collaborative partnerships with U.S. Industry, Academia, and other Government Agencies, have made significant progress toward reaching the N+2 (2020) and N+3 (beyond 2025) installed fuel burn goals by fundamental aircraft engine technology development, subscale component experimental investigations, full scale integrated systems validation testing, and development validation of state of the art computation design and analysis codes. Specific areas of propulsion technology research are discussed and progress to date.

  14. Engine Conceptual Design Studies for a Hybrid Wing Body Aircraft

    NASA Technical Reports Server (NTRS)

    Tong, Michael T.; Jones, Scott M.; Haller, William J.; Handschuh, Robert F.

    2009-01-01

    Worldwide concerns of air quality and climate change have made environmental protection one of the most critical issues in aviation today. NASA s current Fundamental Aeronautics Research program is directed at three generations of aircraft in the near, mid and far term, with initial operating capability around 2015, 2020, and 2030, respectively. Each generation has associated goals for fuel burn, NOx, noise, and field-length reductions relative to today s aircrafts. The research for the 2020 generation is directed at enabling a hybrid wing body (HWB) aircraft to meet NASA s aggressive technology goals. This paper presents the conceptual cycle and mechanical designs of the two engine concepts, podded and embedded systems, which were proposed for a HWB cargo freighter. They are expected to offer significant benefits in noise reductions without compromising the fuel burn.

  15. Heat Transfer Analysis of the NAHBE Piston Cap,

    DTIC Science & Technology

    1977-09-01

    r~~~ U____________ ____s HEAT TRANSFER ANALYSIS :~ OF THE NAHBE PISTON CAP* Engineering and Wea pons Report EW-l1—77...transfer variations in thecap of a nodified piston engine (NN~BE) was made. The objective was to estimatethe regenerative heating effect d~e to the cap...ABSTRACT The piston modification for the NAHBE (Naval Academy Heat Bal ance Engine ) consists of a cap which extends above the standard piston used

  16. Aircraft Turbine Engine Monitoring Experience: Implications for the F100 Engine Diagnostic System Program

    DTIC Science & Technology

    1979-04-01

    malfunction re- port data were obtained from the Program Office. -8- EHMS (T-38 / J85 ) ACTIVITY OUTCOMES JULY 76 - MAY 77 INSTRUMENTED ENGINES CONTROL...interesting to note that the J85 was a mature engine and that the number of engine problems encountered was not very great. Also, the EHMS was not a new...copyright notation hereon. Library of Congress Cataloging In PObNiation Data Birkier, John L Aircraft turbine engine monitoring experience. ([Report

  17. Piston rod seal

    DOEpatents

    Lindskoug, Stefan

    1984-01-01

    In a piston rod seal of the type comprising a gland through which the piston rod is passed the piston is provided with a sleeve surrounding the piston rod and extending axially so as to axially partly overlap the gland when the piston is in its bottom dead center position.

  18. Carbon-Carbon Piston Architectures

    NASA Technical Reports Server (NTRS)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    1999-01-01

    An improved structure for carbon-carbon composite piston architectures consists of replacing the knitted fiber, three-dimensional piston preform architecture described in U.S. Pat. No. 4.909,133 (Taylor et al.) with a two-dimensional lay-up or molding of carbon fiber fabric or tape. Initially. the carbon fabric or tape layers are prepregged with carbonaceous organic resins and/or pitches and are laid up or molded about a mandrel. to form a carbon-fiber reinforced organic-matrix composite part shaped like a "U" channel, a "T"-bar. or a combination of the two. The molded carbon-fiber reinforced organic-matrix composite part is then pyrolized in an inert atmosphere, to convert the organic matrix materials to carbon. At this point, cylindrical piston blanks are cored from the "U" channel, "T"-bar, or combination part. These blanks are then densified by reimpregnation with resins or pitches which are subsequently carbonized. Densification is also be accomplished by direct infiltration with carbon by vapor deposition processes. Once the desired density has been achieved, the piston billets are machined to final piston dimensions; coated with oxidation sealants; and/or coated with a catalyst. When compared to conventional steel or aluminum-alloy pistons, the use of carbon-carbon composite pistons reduces the overall weight of the engine; allows for operation at higher temperatures without a loss of strength; allows for quieter operation; reduces the heat loss; and reduces the level of hydrocarbon emissions.

  19. On the turbulent flow in piston engines: Coupling of statistical theory quantities and instantaneous turbulence

    NASA Astrophysics Data System (ADS)

    Zentgraf, Florian; Baum, Elias; Böhm, Benjamin; Dreizler, Andreas; Peterson, Brian

    2016-04-01

    Planar particle image velocimetry (PIV) and tomographic PIV (TPIV) measurements are utilized to analyze turbulent statistical theory quantities and the instantaneous turbulence within a single-cylinder optical engine. Measurements are performed during the intake and mid-compression stroke at 800 and 1500 RPM. TPIV facilitates the evaluation of spatially resolved Reynolds stress tensor (RST) distributions, anisotropic Reynolds stress invariants, and instantaneous turbulent vortical structures. The RST analysis describes distributions of individual velocity fluctuation components that arise from unsteady turbulent flow behavior as well as cycle-to-cycle variability (CCV). A conditional analysis, for which instantaneous PIV images are sampled by their tumble center location, reveals that CCV and turbulence have similar contributions to RST distributions at the mean tumble center, but turbulence is dominant in regions peripheral to the tumble center. Analysis of the anisotropic Reynolds stress invariants reveals the spatial distribution of axisymmetric expansion, axisymmetric contraction, and 3D isotropy within the cylinder. Findings indicate that the mid-compression flow exhibits a higher tendency toward 3D isotropy than the intake flow. A novel post-processing algorithm is utilized to classify the geometry of instantaneous turbulent vortical structures and evaluate their frequency of occurrence within the cylinder. Findings are coupled with statistical theory quantities to provide a comprehensive understanding of the distribution of turbulent velocity components, the distribution of anisotropic states of turbulence, and compare the turbulent vortical flow distribution that is theoretically expected to what is experimentally observed. The analyses reveal requisites of important turbulent flow quantities and discern their sensitivity to the local flow topography and engine operation.

  20. An Extended Combustion Model for the Aircraft Turbojet Engine

    NASA Astrophysics Data System (ADS)

    Rotaru, Constantin; Andres-Mihăilă, Mihai; Matei, Pericle Gabriel

    2014-08-01

    The paper consists in modelling and simulation of the combustion in a turbojet engine in order to find optimal characteristics of the burning process and the optimal shape of combustion chambers. The main focus of this paper is to find a new configuration of the aircraft engine combustion chambers, namely an engine with two main combustion chambers, one on the same position like in classical configuration, between compressor and turbine and the other, placed behind the turbine but not performing the role of the afterburning. This constructive solution could allow a lower engine rotational speed, a lower temperature in front of the first stage of the turbine and the possibility to increase the turbine pressure ratio by extracting the flow stream after turbine in the inner nozzle. Also, a higher thermodynamic cycle efficiency and thrust in comparison to traditional constant-pressure combustion gas turbine engines could be obtained.

  1. Primary VOC emissions from Commercial Aircraft Jet Engines

    NASA Astrophysics Data System (ADS)

    Kilic, Dogushan; Huang, Rujin; Slowik, Jay; Brem, Benjamin; Durdina, Lukas; Rindlisbacher, Theo; Baltensperger, Urs; Prevot, Andre

    2014-05-01

    Air traffic is growing continuously [1]. The increasing number of airplanes leads to an increase of aviation emissions giving rise to environmental concerns globally by high altitude emissions and, locally on air quality at the ground level [2]. The overall impact of aviation emissions on the environment is likely to increase when the growing air transportation trend [2] is considered. The Aviation Particle Regulatory Instrumentation Demonstration Experiment (APRIDE)-5 campaign took place at Zurich Airport in 2013. In this campaign, aircraft exhaust is sampled during engine acceptance tests after engine overhaul at the facilities of SR Technics. Direct sampling from the engine core is made possible due to the unique fixed installation of a retractable sampling probe and the use of a standardized sampling system designed for the new particulate matter regulation in development for aircraft engines. Many of the gas-phase aircraft emissions, e.g. CO2, NOX, CO, SO2, hydrocarbons, and volatile organic compounds (VOC) were detected by the instruments in use. This study, part of the APRIDE-5 campaign, focuses on the primary VOC emissions in order to produce emission factors of VOC species for varying engine operating conditions which are the surrogates for the flight cycles. Previously, aircraft plumes were sampled in order to quantify VOCs by a proton transfer reaction quadrupole mass spectrometer (PTR-MS) [3]. This earlier study provided a preliminary knowledge on the emission of species such as methanol, acetaldehyde, acetone, benzene and toluene by varying engine thrust levels. The new setup was (i) designed to sample from the diluted engine exhaust and the new tool and (ii) used a high resolution time of flight PTR-MS with higher accuracy for many new species, therefore providing a more detailed and accurate inventory. We will present the emission factors for species that were quantified previously, as well as for many additional VOCs detected during the campaign

  2. Cobalt: A vital element in the aircraft engine industry

    NASA Technical Reports Server (NTRS)

    Stephens, J. R.

    1981-01-01

    Recent trends in the United States consumption of cobalt indicate that superalloys for aircraft engine manufacture require increasing amounts of this strategic element. Superalloys consume a lion's share of total U.S. cobalt usage which was about 16 million pounds in 1980. In excess of 90 percent of the cobalt used in this country was imported, principally from the African countries of Zaire and Zambia. Early studies on the roles of cobalt as an alloying element in high temperature alloys concentrated on the simple Ni-Cr and Nimonic alloy series. The role of cobalt in current complex nickel base superalloys is not well defined and indeed, the need for the high concentration of cobalt in widely used nickel base superalloys is not firmly established. The current cobalt situation is reviewed as it applies to superalloys and the opportunities for research to reduce the consumption of cobalt in the aircraft engine industry are described.

  3. Active Combustion Control for Aircraft Gas Turbine Engines

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  4. Carbureting conditions characteristics of aircraft engines

    NASA Technical Reports Server (NTRS)

    Tice, Percival S

    1920-01-01

    Tests were conducted at the altitude laboratory erected at the Bureau of Standards for the National Advisory Committee for Aeronautics to determine the changes in engine performance with changes in atmospheric temperature and pressure at various levels above the earth's surface, with special reference to (a) the variables affecting the functioning of the carburetor and (b) the changes in performance resulting from variables in the carburetor itself. This report constitutes a concise statement of the difficulties to be encountered in this branch of carburetion.

  5. Rapid Measurement of Emissions From Military Aircraft Turbine Engines by Downstream Extractive Sampling of Aircraft on the Ground: Results for C-130 and F-15 Aircraft (POSTPRINT)

    DTIC Science & Technology

    2009-02-01

    engines were tested using indoor engine test facilities (F110, F101, J85 -GE-5M, PT6A-68, TF41-A2, TF30-P103 and TF30- P109), while others were studied while...afterburning). Engine T56-A-15 F100-PW-100 F110 F101 J85 -GE-5M PT6A-68 TF-39-1C CFM-56-3 TF41-A2 TF30-P103 TF30-P109 Misc. Type Turboprop Turbofan...AIRCRAFT TURBINE ENGINES BY DOWNSTREAM EXTRACTIVE SAMPLING OF AIRCRAFT ON THE GROUND: RESULTS FOR C-130 AND F-15 AIRCRAFT Chester Spicer and

  6. 76 FR 19903 - Special Conditions: Diamond Aircraft Industry Model DA-40NG; Diesel Cycle Engine

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-11

    ... Conditions: Diamond Aircraft Industry Model DA-40NG; Diesel Cycle Engine AGENCY: Federal Aviation... conditions are issued for the Diamond Aircraft Industry (DAI) GmbH model DA-40NG the Austro Engine GmbH model... the postcard and mail it back to you. Background On May 11, 2010 Diamond Aircraft Industry...

  7. Researches on the Piston Ring

    NASA Technical Reports Server (NTRS)

    Ehihara, Keikiti

    1944-01-01

    In internal combustion engines, steam engines, air compressors, and so forth, the piston ring plays an important role. Especially, the recent development of Diesel engines which require a high compression pressure for their working, makes, nowadays, the packing action of the piston ring far more important than ever. Though a number of papers have been published in regard to researches on the problem of the piston ring, none has yet dealt with an exact measurement of pressure exerted on the cylinder wall at any given point of the ring. The only paper that can be traced on this subject so far is Mr. Nakagawa's report on the determination of the relative distribution of pressure on the cylinder wall, but the measuring method adopted therein appears to need further consideration. No exact idea has yet been obtained as to how the obturation of gas between the piston and cylinder, the frictional resistance of the piston, and the wear of the cylinder wall are affected by the intensity and the distribution of the radial pressure of the piston ring. Consequently, the author has endeavored, by employing an apparatus of his own invention, to get an exact determination of the pressure distribution of the piston ring. By means of a newly devised ring tester, to which piezoelectricity of quartz was applied, the distribution of the radial pressure of many sample rings on the market was accurately determined. Since many famous piston rings show very irregular pressure distribution, the author investigated and achieved a manufacturing process of the piston ring which will exert uniform pressure on the cylinder wall. Temperature effects on the configuration and on the mean spring power have also been studied. Further, the tests were performed to ascertain how the gas tightness of the piston ring may be affected by the number or spring power. The researches as to the frictional resistance between the piston ring and the cylinder wall were carried out, too. The procedure of study, and

  8. Computation of Engine Noise Propagation and Scattering Off an Aircraft

    NASA Technical Reports Server (NTRS)

    Xu, J.; Stanescu, D.; Hussaini, M. Y.; Farassat, F.

    2003-01-01

    The paper presents a comparison of experimental noise data measured in flight on a two-engine business jet aircraft with Kulite microphones placed on the suction surface of the wing with computational results. Both a time-domain discontinuous Galerkin spectral method and a frequency-domain spectral element method are used to simulate the radiation of the dominant spinning mode from the engine and its reflection and scattering by the fuselage and the wing. Both methods are implemented in computer codes that use the distributed memory model to make use of large parallel architectures. The results show that trends of the noise field are well predicted by both methods.

  9. Time-resolved nature of exhaust gas emissions and piston wall temperature under transient operation in a small diesel engine

    SciTech Connect

    Reksowardojo, I.K.; Ogawa, Hideyuki; Miyamoto, Noboru; Enomoto, Yoshiteru; Kitamura, Toru

    1996-09-01

    Diesel combustion and exhaust gas emissions under transient operation (when fuel amounts abruptly increased) were investigated under a wide range of operating conditions with a newly developed gas sampling system. The relation between gas emissions and piston wall temperatures was also investigated. The results indicated that after the start of acceleration NOx, THC and smoke showed transient behaviors before reaching the steady state condition. Of the three gases, THC was most affected by piston wall temperature; its concentration decreased as the wall temperature increased throughout the acceleration except immediately after the start of acceleration. The number of cycles, at which gas concentrations reach the steady-state value after the start of acceleration, were about 1.2 times the cycle constant of the piston wall temperature for THC, and 2.3 times for smoke.

  10. DEVELOPMENT OF A SUPERSONIC TRANSPORT AIRCRAFT ENGINE - PHASE II-A.

    DTIC Science & Technology

    JET TRANSPORT PLANES, *SUPERSONIC AIRCRAFT ) (U) TURBOJET ENGINES , PERFORMANCE( ENGINEERING ), TURBOFAN ENGINES , AFTERBURNING, SPECIFICATIONS...COMPRESSORS, GEOMETRY, TURBOJET INLETS, COMBUSTION, TEST EQUIPMENT, TURBINE BLADES , HEAT TRANSFER, AIRFOILS , CASCADE STRUCTURES, EVAPOTRANSPIRATION, PLUG NOZZLES, ANECHOIC CHAMBERS, BEARINGS, SEALS, DESIGN, FATIGUE(MECHANICS)

  11. A study of external fuel vaporization. [for aircraft gas turbine engines

    NASA Technical Reports Server (NTRS)

    Szetela, E. J.; Chiappetta, L.; Baker, C. E.

    1981-01-01

    Candidate external vaporizer designs for an aircraft gas turbine engine are evaluated with respect to fuel thermal stability, integration of the vaporizer system into the aircraft engine, engine and vaporizer dynamic response, startup and altitude restart, engine performance, control requirements, safety, and maintenance. The selected concept is shown to offer potential gains in engine performance in terms of reduced specific fuel consumption and improved engine thrust/weight ratio. The thrust/weight improvement can be traded against vaporization system weight.

  12. Characterization of emissions from commercial aircraft engines during the Aircraft Particle Emissions eXperiment (APEX) 1 to 3

    EPA Science Inventory

    The fine particulate matter emissions from aircraft operations at large airports located in areas of the U. S. designated as non-attainment for the National Ambient Air Quality Standard for PM-2.5 are of major environmental concern. PM emissions data for commercial aircraft engin...

  13. 76 FR 45011 - Control of Air Pollution From Aircraft and Aircraft Engines; Proposed Emission Standards and Test...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ... Environmental Protection Agency 40 CFR Parts 87 and 1068 Control of Air Pollution From Aircraft and Aircraft... AGENCY 40 CFR Parts 87 and 1068 [EPA-HQ-OAR-2010-0687; FRL-9437-2] RIN 2060-AO70 Control of Air Pollution... engines which in her judgment causes or contributes to air pollution that may reasonably be anticipated...

  14. 77 FR 65823 - Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-31

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 87 RIN 2060-AO70 Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures Correction In rule document 2012-13828 appearing on pages...

  15. 77 FR 36341 - Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ... nitrogen (NO X ), compliance flexibilities, and other regulatory requirements for aircraft turbofan or... Exposure to Ozone, PM and NO X a. Deposition of Nitrogen b. Visibility Effects c. Plant and Ecosystem... nitrogen (NO X ) emission standards for aircraft engines with rated thrusts greater than 26.7 kN...

  16. Aircraft Engine Noise Scattering - A Discontinuous Spectral Element Approach

    NASA Technical Reports Server (NTRS)

    Stanescu, D.; Hussaini, M. Y.; Farassat, F.

    2002-01-01

    The paper presents a time-domain method for computation of sound radiation from aircraft engine sources to the far-field. The effects of nonuniform flow around the aircraft and scattering of sound by fuselage and wings are accounted for in the formulation. Our approach is based on the discretization of the inviscid flow equations through a collocation form of the Discontinuous Galerkin spectral element method. An isoparametric representation of the underlying geometry is used in order to take full advantage of the spectral accuracy of the method. Largescale computations are made possible by a parallel implementation based on message passing. Results obtained for radiation from an axisymmetric nacelle alone are compared with those obtained when the same nacelle is installed in a generic con.guration, with and without a wing.

  17. Aircraft Engine Gas Path Diagnostic Methods: Public Benchmarking Results

    NASA Technical Reports Server (NTRS)

    Simon, Donald L.; Borguet, Sebastien; Leonard, Olivier; Zhang, Xiaodong (Frank)

    2013-01-01

    Recent technology reviews have identified the need for objective assessments of aircraft engine health management (EHM) technologies. To help address this issue, a gas path diagnostic benchmark problem has been created and made publicly available. This software tool, referred to as the Propulsion Diagnostic Method Evaluation Strategy (ProDiMES), has been constructed based on feedback provided by the aircraft EHM community. It provides a standard benchmark problem enabling users to develop, evaluate and compare diagnostic methods. This paper will present an overview of ProDiMES along with a description of four gas path diagnostic methods developed and applied to the problem. These methods, which include analytical and empirical diagnostic techniques, will be described and associated blind-test-case metric results will be presented and compared. Lessons learned along with recommendations for improving the public benchmarking processes will also be presented and discussed.

  18. Lightweight diesel engine designs for commuter type aircraft

    NASA Technical Reports Server (NTRS)

    Brouwers, A. P.

    1981-01-01

    Conceptual designs and performance of advanced technology lightweight diesel engines, suitable for commuter type aircraft power plants are defined. Two engines are discussed, a 1491 kW (2000 SHP) eight-cylinder engine and a 895 kW (1200 SHP) six-cylinder engine. High performance and related advanced technologies are proposed such as insulated cylinders, very high injection pressures and high compressor and turbine efficiencies. The description of each engine includes concept drawings, a performance analysis, and weight data. Fuel flow data are given for full and partial power up to 7620m altitude. The performance data are also extrapolated over a power range from 671 kW(900SHP) to 1864 kW (2500 SHP). The specific fuel consumption of the 1491 kW (2000 SHP) engine is 182 g/hWh (.299 lb/HPh) at cruise altitude, its weight 620 kg (1365 lb.) and specific weight .415 kg/kW (.683 lb/HP). The specific fuel consumption of the 895 kW (1200 SHP) engine is 187 g/hWh (.308 lb/HPh) at cruise altitude, its weight 465 kg (1025 lb.) and specific weight .520 kg/kW (.854 lb/HP).

  19. Compact crank drive mechanism with guided pistons

    SciTech Connect

    Ross, M.A.; Beale, W.T.

    1988-04-19

    This patent describes an improved engine of the type having at least two pistons which reciprocate with a desired phase difference in two adjacent cylinders in a housing and having a crankshaft linked to the pistons by a crank drive mechanism formed by a yoke and a rocking lever. The yoke has a central pair of pivot axes and a pair of laterally distal pivot axes spaced on opposite sides of the central axes and each connected by a connecting rod to a different one of the pistons. One of the cental pivot axes is rotatably attached to a throw of the crankshaft. The rocking lever is pivotally attached to one end to the second central pivot axis of the yoke and extending laterally into pivotal attachment with the housing wherein the improvement comprises: (a) a first one of the pistons having a rigidly attached piston rod to form a first rocker piston which is pivotally connected to the yoke distal pivot axis which is laterally opposite the rocking lever, the first piston having a portion extending substantially into its cylinder, and (b) the second piston having a rocker piston having rigidly attached piston rod pivotally attached to the other yoke distal pivot axis.

  20. The knocking characteristics of fuels in relation to maximum permissible performance of aircraft engines

    NASA Technical Reports Server (NTRS)

    Rothrock, A M; Biermann, Arnold E

    1939-01-01

    An analysis is presented of the relationship of various engine factors to knock in preignition in an aircraft engine. From this analysis and from the available experimental data, a method of evaluating the knocking characteristics of the fuel in an aircraft-engine cylinder is suggested.

  1. Life-Extending Control for Aircraft Engines Studied

    NASA Technical Reports Server (NTRS)

    Guo, Te-Huei

    2002-01-01

    Current aircraft engine controllers are designed and operated to provide both performance and stability margins. However, the standard method of operation results in significant wear and tear on the engine and negatively affects the on-wing life--the time between cycles when the engine must be physically removed from the aircraft for maintenance. The NASA Glenn Research Center and its industrial and academic partners have been working together toward a new control concept that will include engine life usage as part of the control function. The resulting controller will be able to significantly extend the engine's on-wing life with little or no impact on engine performance and operability. The new controller design will utilize damage models to estimate and mitigate the rate and overall accumulation of damage to critical engine parts. The control methods will also provide a means to assess tradeoffs between performance and structural durability on the basis of mission requirements and remaining engine life. Two life-extending control methodologies were studied to reduce the overall life-cycle cost of aircraft engines. The first methodology is to modify the baseline control logic to reduce the thermomechanical fatigue (TMF) damage of cooled stators during acceleration. To accomplish this, an innovative algorithm limits the low-speed rotor acceleration command when the engine has reached a threshold close to the requested thrust. This algorithm allows a significant reduction in TMF damage with only a very small increase in the rise time to reach the commanded rotor speed. The second methodology is to reduce stress rupture/creep damage to turbine blades and uncooled stators by incorporating an engine damage model into the flight mission. Overall operation cost is reduced by an optimization among the flight time, fuel consumption, and component damages. Recent efforts have focused on applying life-extending control technology to an existing commercial turbine engine

  2. A Study of Bird Ingestions Into Large High Bypass Ratio Turbine Aircraft Engines.

    DTIC Science & Technology

    1983-03-01

    into large high bypass ratio turbine aircraft engines on a worldwide basis and what damage , if any, resulted. This interim report presents a summary...operations. These aircraft experienced 289 engine ingestion events during the initial contract * period, May 1961 through April 1982. The FAA is...Airports involved 88 3. Total events 289 4. hngine damage , minor and/or major 188 5. Multiple engine ingestions per aircraft 11 6. MuLtiple bird

  3. Experimental Studies of Coal and Biomass Fuel Synthesis and Flame Characterization for Aircraft Engines

    DTIC Science & Technology

    2012-03-31

    Synthesis and Flame Characterization for Aircraft Engines 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-10-1-0344 5c. PROGRAM ELEMENT NUMBER 61102F... Flame Characterization for Aircraft Engines AFOSR Grant Number: FA9550-10-1-0344 Final Performance Report Report Period: September 1, 2008 to... Flame Characterization for Aircraft Engines (Final Performance Report) Project Period: September 1, 2008 to March 31, 2012 Report Period

  4. Near-field commercial aircraft contribution to nitrogen oxides by engine, aircraft type, and airline by individual plume sampling.

    PubMed

    Carslaw, David C; Ropkins, Karl; Laxen, Duncan; Moorcroft, Stephen; Marner, Ben; Williams, Martin L

    2008-03-15

    Nitrogen oxides (NOx) concentrations were measured in individual plumes from aircraft departing on the northern runway at Heathrow Airport in west London. Over a period of four weeks 5618 individual plumes were sampled by a chemiluminescence monitor located 180 m from the runway. Results were processed and matched with detailed aircraft movement and aircraft engine data using chromatographic techniques. Peak concentrations associated with 29 commonly used engines were calculated and found to have a good relationship with N0x emissions taken from the International Civil Aviation Organization (ICAO) databank. However, it is found that engines with higher reported NOx emissions result in proportionately lower NOx concentrations than engines with lower emissions. We show that it is likely that aircraft operational factors such as takeoff weight and aircraftthrust setting have a measurable and important effect on concentrations of N0x. For example, NOx concentrations can differ by up to 41% for aircraft using the same airframe and engine type, while those due to the same engine type in different airframes can differ by 28%. These differences are as great as, if not greater than, the reported differences in NOx emissions between different engine manufacturers for engines used on the same airframe.

  5. Drive piston assembly for a valve actuator assembly

    DOEpatents

    Sun, Zongxuan

    2010-02-23

    A drive piston assembly is provided that is operable to selectively open a poppet valve. The drive piston assembly includes a cartridge defining a generally stepped bore. A drive piston is movable within the generally stepped bore and a boost sleeve is coaxially disposed with respect to the drive piston. A main fluid chamber is at least partially defined by the generally stepped bore, drive piston, and boost sleeve. First and second feedback chambers are at least partially defined by the drive piston and each are disposed at opposite ends of the drive piston. At least one of the drive piston and the boost sleeve is sufficiently configured to move within the generally stepped bore in response to fluid pressure within the main fluid chamber to selectively open the poppet valve. A valve actuator assembly and engine are also provided incorporating the disclosed drive piston assembly.

  6. NACA's 9th Annual Aircraft Engineering Research Conference

    NASA Technical Reports Server (NTRS)

    1934-01-01

    Eight of the twelve members of the National Advisory Committee for Aeronautics attending the 9th Annual Aircraft Engineering Research Conference posed for this photograph at Langley Field, Virginia, on May 23, 1934. Those pictured are (left to right): Brig. Gen. Charles A. Lindbergh, USAFR Vice Admiral Arthur B. Cook, USN Charles G. Abbot, Secretary of the Smithsonian Institution Dr. Joseph S. Ames, Committee Chairman Orville Wright Edward P. Warner Fleet Admiral Ernest J. King, USN Eugene L. Vidal, Director, Bureau of Air Commerce.

  7. Structureborne noise measurements on a small twin-engine aircraft

    NASA Technical Reports Server (NTRS)

    Cole, J. E., III; Martini, K. F.

    1988-01-01

    Structureborne noise measurements performed on a twin-engine aircraft (Beechcraft Baron) are reported. There are two overall objectives of the test program. The first is to obtain data to support the development of analytical models of the wing and fuselage, while the second is to evaluate effects of structural parameters on cabin noise. Measurements performed include structural and acoustic responses to impact excitation, structural and acoustic loss factors, and modal parameters of the wing. Path alterations include added mass to simulate fuel, variations in torque of bolts joining wing and fuselage, and increased acoustic absorption. Conclusions drawn regarding these measurements are presented.

  8. Structureborne noise measurements on a small twin-engine aircraft

    NASA Astrophysics Data System (ADS)

    Cole, J. E., III; Martini, K. F.

    1988-06-01

    Structureborne noise measurements performed on a twin-engine aircraft (Beechcraft Baron) are reported. There are two overall objectives of the test program. The first is to obtain data to support the development of analytical models of the wing and fuselage, while the second is to evaluate effects of structural parameters on cabin noise. Measurements performed include structural and acoustic responses to impact excitation, structural and acoustic loss factors, and modal parameters of the wing. Path alterations include added mass to simulate fuel, variations in torque of bolts joining wing and fuselage, and increased acoustic absorption. Conclusions drawn regarding these measurements are presented.

  9. A technique for integrating engine cycle and aircraft configuration optimization

    NASA Technical Reports Server (NTRS)

    Geiselhart, Karl A.

    1994-01-01

    A method for conceptual aircraft design that incorporates the optimization of major engine design variables for a variety of cycle types was developed. The methodology should improve the lengthy screening process currently involved in selecting an appropriate engine cycle for a given application or mission. The new capability will allow environmental concerns such as airport noise and emissions to be addressed early in the design process. The ability to rapidly perform optimization and parametric variations using both engine cycle and aircraft design variables, and to see the impact on the aircraft, should provide insight and guidance for more detailed studies. A brief description of the aircraft performance and mission analysis program and the engine cycle analysis program that were used is given. A new method of predicting propulsion system weight and dimensions using thermodynamic cycle data, preliminary design, and semi-empirical techniques is introduced. Propulsion system performance and weights data generated by the program are compared with industry data and data generated using well established codes. The ability of the optimization techniques to locate an optimum is demonstrated and some of the problems that had to be solved to accomplish this are illustrated. Results from the application of the program to the analysis of three supersonic transport concepts installed with mixed flow turbofans are presented. The results from the application to a Mach 2.4, 5000 n.mi. transport indicate that the optimum bypass ratio is near 0.45 with less than 1 percent variation in minimum gross weight for bypass ratios ranging from 0.3 to 0.6. In the final application of the program, a low sonic boom fix a takeoff gross weight concept that would fly at Mach 2.0 overwater and at Mach 1.6 overland is compared with a baseline concept of the same takeoff gross weight that would fly Mach 2.4 overwater and subsonically overland. The results indicate that for the design mission

  10. An Integrated Architecture for Aircraft Engine Performance Monitoring and Fault Diagnostics: Engine Test Results

    NASA Technical Reports Server (NTRS)

    Rinehart, Aidan W.; Simon, Donald L.

    2015-01-01

    This paper presents a model-based architecture for performance trend monitoring and gas path fault diagnostics designed for analyzing streaming transient aircraft engine measurement data. The technique analyzes residuals between sensed engine outputs and model predicted outputs for fault detection and isolation purposes. Diagnostic results from the application of the approach to test data acquired from an aircraft turbofan engine are presented. The approach is found to avoid false alarms when presented nominal fault-free data. Additionally, the approach is found to successfully detect and isolate gas path seeded-faults under steady-state operating scenarios although some fault misclassifications are noted during engine transients. Recommendations for follow-on maturation and evaluation of the technique are also presented.

  11. An Integrated Architecture for Aircraft Engine Performance Monitoring and Fault Diagnostics: Engine Test Results

    NASA Technical Reports Server (NTRS)

    Rinehart, Aidan W.; Simon, Donald L.

    2014-01-01

    This paper presents a model-based architecture for performance trend monitoring and gas path fault diagnostics designed for analyzing streaming transient aircraft engine measurement data. The technique analyzes residuals between sensed engine outputs and model predicted outputs for fault detection and isolation purposes. Diagnostic results from the application of the approach to test data acquired from an aircraft turbofan engine are presented. The approach is found to avoid false alarms when presented nominal fault-free data. Additionally, the approach is found to successfully detect and isolate gas path seeded-faults under steady-state operating scenarios although some fault misclassifications are noted during engine transients. Recommendations for follow-on maturation and evaluation of the technique are also presented.

  12. 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.

  13. Fiber optics for aircraft engine/inlet control

    NASA Technical Reports Server (NTRS)

    Baumbick, R. J.

    1981-01-01

    NASA programs that focus on the use of fiber optics for aircraft engine/inlet control are reviewed. Fiber optics for aircraft control is attractive because of its inherent immunity to EMI and RFI noise. Optical signals can be safely transmitted through areas that contain flammable or explosive materials. The use of optics also makes remote sensing feasible by eliminating the need for electrical wires to be connected between sensors and computers. Using low-level optical signals to control actuators is also feasible when power is generated at the actuator. Each application of fiber optics for aircraft control has different requirements for both the optical cables and the optical connectors. Sensors that measure position and speed by using slotted plates can use lossy cables and bundle connectors if data transfer is in the parallel mode. If position and speed signals are multiplexed, cable and connector requirements change. Other sensors that depend on changes in transmission through materials require dependable characteristics of both the optical cables and the optical connectors. A variety of sensor types are reviewed, including rotary position encoders, tachometers, temperature sensors, and blade tip clearance sensors for compressors and turbines. Research on a gallium arsenide photoswitch for optically switched actuators that operate at 250 C is also described.

  14. Spherical Joint Piston and Connecting Rod Developed

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Under an interagency agreement with the Department of Energy, the NASA Lewis Research Center manages a Heavy-Duty Diesel Engine Technology (HDET) research program. The overall program objectives are to reduce fuel consumption through increased engine efficiency, reduce engine exhaust emissions, and provide options for the use of alternative fuels. The program is administered with a balance of research contracts, university research grants, and focused in-house research. The Cummins Engine Company participates in the HDET program under a cost-sharing research contract. Cummins is researching and developing in-cylinder component technologies for heavy-duty diesel engines. An objective of the Cummins research is to develop technologies for a low-emissions, 55-percent thermal efficiency (LE-55) engine. The best current-production engines in this class achieve about 46-percent thermal efficiency. Federal emissions regulations are driving this technology. Regulations for heavy duty diesel engines were tightened in 1994, more demanding emissions regulations are scheduled for 1998, and another step is planned for 2002. The LE-55 engine emissions goal is set at half of the 1998 regulation level and is consistent with plans for 2002 emissions regulations. LE-55 engine design requirements to meet the efficiency target dictate a need to operate at higher peak cylinder pressures. A key technology being developed and evaluated under the Cummins Engine Company LE-55 engine concept is the spherical joint piston and connecting rod. Unlike conventional piston and connecting rod arrangements which are joined by a pin forming a hinged joint, the spherical joint piston and connecting rod use a ball-and-socket joint. The ball-and-socket arrangement enables the piston to have an axisymmetric design allowing rotation within the cylinder. The potential benefits of piston symmetry and rotation are reduced scuffing, improved piston ring sealing, improved lubrication, mechanical and thermal

  15. Structural Optimization Methodology for Rotating Disks of Aircraft Engines

    NASA Technical Reports Server (NTRS)

    Armand, Sasan C.

    1995-01-01

    In support of the preliminary evaluation of various engine technologies, a methodology has been developed for structurally designing the rotating disks of an aircraft engine. The structural design methodology, along with a previously derived methodology for predicting low-cycle fatigue life, was implemented in a computer program. An interface computer program was also developed that gathers the required data from a flowpath analysis program (WATE) being used at NASA Lewis. The computer program developed for this study requires minimum interaction with the user, thus allowing engineers with varying backgrounds in aeropropulsion to successfully execute it. The stress analysis portion of the methodology and the computer program were verified by employing the finite element analysis method. The 10th- stage, high-pressure-compressor disk of the Energy Efficient Engine Program (E3) engine was used to verify the stress analysis; the differences between the stresses and displacements obtained from the computer program developed for this study and from the finite element analysis were all below 3 percent for the problem solved. The computer program developed for this study was employed to structurally optimize the rotating disks of the E3 high-pressure compressor. The rotating disks designed by the computer program in this study were approximately 26 percent lighter than calculated from the E3 drawings. The methodology is presented herein.

  16. Application of superalloy powder metallurgy for aircraft engines

    NASA Technical Reports Server (NTRS)

    Dreshfield, R. L.; Miner, R. V., Jr.

    1980-01-01

    In the last decade, Government/Industry programs have advanced powder metallurgy-near-net-shape technology to permit the use of hot isostatic pressed (HIP) turbine disks in the commercial aircraft fleet. These disks offer a 30% savings of input weight and an 8% savings in cost compared in cast-and-wrought disks. Similar savings were demonstrated for other rotating engine components. A compressor rotor fabricated from hot-die-forged-HIP superalloy billets revealed input weight savings of 54% and cost savings of 35% compared to cast-and-wrought parts. Engine components can be produced from compositions such as Rene 95 and Astroloy by conventional casting and forging, by forging of HIP powder billets, or by direct consolidation of powder by HIP. However, each process produces differences in microstructure or introduces different defects in the parts. As a result, their mechanical properties are not necessarily identical. Acceptance methods should be developed which recognize and account for the differences.

  17. Commercial Aircraft Maintenance Experience Relating to Engine External Hardware

    NASA Technical Reports Server (NTRS)

    Soditus, Sharon M.

    2006-01-01

    Airlines are extremely sensitive to the amount of dollars spent on maintaining the external engine hardware in the field. Analysis reveals that many problems revolve around a central issue, reliability. Fuel and oil leakage due to seal failure and electrical fault messages due to wire harness failures play a major role in aircraft delays and cancellations (D&C's) and scheduled maintenance. Correcting these items on the line requires a large investment of engineering resources and manpower after the fact. The smartest and most cost effective philosophy is to build the best hardware the first time. The only way to do that is to completely understand and model the operating environment, study the field experience of similar designs and to perform extensive testing.

  18. Simulation of Aircraft Engine Blade-Out Structural Dynamics. Revised

    NASA Technical Reports Server (NTRS)

    Lawrence, Charles; Carney, Kelly; Gallardo, Vicente

    2001-01-01

    A primary concern of aircraft structure designers is the accurate simulation of the blade-out event and the subsequent windmilling of the engine. Reliable simulations of the blade-out event are required to insure structural integrity during flight as well as to guarantee successful blade-out certification testing. The system simulation includes the lost blade loadings and the interactions between the rotating turbomachinery and the remaining aircraft structural components. General-purpose finite element structural analysis codes such as MSC NASTRAN are typically used and special provisions are made to include transient effects from the blade loss and rotational effects resulting from the engine's turbomachinery. The present study provides the equations of motion for rotordynamic response including the effect of spooldown speed and rotor unbalance and examines the effects of these terms on a cantilevered rotor. The effect of spooldown speed is found to be greater with increasing spooldown rate. The parametric term resulting from the mass unbalance has a more significant effect on the rotordynamic response than does the spooldown term. The parametric term affects both the peak amplitudes as well as the resonant frequencies of the rotor.

  19. Simulation of Aircraft Engine Blade-Out Structural Dynamics

    NASA Technical Reports Server (NTRS)

    Lawrence, Charles; Carney, Kelly; Gallardo, Vicente

    2001-01-01

    A primary concern of aircraft structure designers is the accurate simulation of the blade-out event and the subsequent windmilling of the engine. Reliable simulations of the blade-out event are required to insure structural integrity during flight as well as to guarantee successful blade-out certification testing. The system simulation includes the lost blade loadings and the interactions between the rotating turbomachinery and the remaining aircraft structural components. General-purpose finite element structural analysis codes such as MSC NASTRAN are typically used and special provisions are made to include transient effects from the blade loss and rotational effects resulting from the engine's turbomachinery. The present study provides the equations of motion for rotordynamic response including the effect of spooldown speed and rotor unbalance and examines the effects of these terms on a cantilevered rotor. The effect of spooldown speed is found to be greater with increasing spooldown rate. The parametric term resulting from the mass unbalance has a more significant effect on the rotordynamic response than does the spooldown term. The parametric term affects both the peak amplitudes as well as the resonant frequencies of the rotor.

  20. Highly integrated digital electronic control: Digital flight control, aircraft model identification, and adaptive engine control

    NASA Technical Reports Server (NTRS)

    Baer-Riedhart, Jennifer L.; Landy, Robert J.

    1987-01-01

    The highly integrated digital electronic control (HIDEC) program at NASA Ames Research Center, Dryden Flight Research Facility is a multiphase flight research program to quantify the benefits of promising integrated control systems. McDonnell Aircraft Company is the prime contractor, with United Technologies Pratt and Whitney Aircraft, and Lear Siegler Incorporated as major subcontractors. The NASA F-15A testbed aircraft was modified by the HIDEC program by installing a digital electronic flight control system (DEFCS) and replacing the standard F100 (Arab 3) engines with F100 engine model derivative (EMD) engines equipped with digital electronic engine controls (DEEC), and integrating the DEEC's and DEFCS. The modified aircraft provides the capability for testing many integrated control modes involving the flight controls, engine controls, and inlet controls. This paper focuses on the first two phases of the HIDEC program, which are the digital flight control system/aircraft model identification (DEFCS/AMI) phase and the adaptive engine control system (ADECS) phase.

  1. Carbon-Carbon Piston Architectures

    NASA Technical Reports Server (NTRS)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    2000-01-01

    An improved structure for carbon-carbon composite piston architectures is disclosed. The improvement consists of replacing the knitted fiber, three-dimensional piston preform architecture described in U.S. Pat.No. 4,909,133 (Taylor et al.) with a two-dimensional lay-up or molding of carbon fiber fabric or tape. Initially, the carbon fabric of tape layers are prepregged with carbonaceous organic resins and/or pitches and are laid up or molded about a mandrel, to form a carbon-fiber reinforced organic-matrix composite part shaped like a "U" channel, a "T"-bar, or a combination of the two. The molded carbon-fiber reinforced organic-matrix composite part is then pyrolized in an inert atmosphere, to convert the organic matrix materials to carbon. At this point, cylindrical piston blanks are cored from the "U"-channel, "T"-bar, or combination part. These blanks are then densified by reimpregnation with resins or pitches which are subsequently carbonized. Densification is also accomplished by direct infiltration with carbon by vapor deposition processes. Once the desired density has been achieved, the piston billets are machined to final piston dimensions; coated with oxidation sealants; and/or coated with a catalyst. When compared to conventional steel or aluminum alloy pistons, the use of carbon-carbon composite pistons reduces the overall weight of the engine; allows for operation at higher temperatures without a loss of strength; allows for quieter operation; reduces the heat loss; and reduces the level of hydrocarbon emissions.

  2. Comparison of predicted engine core noise with current and proposed aircraft noise certification requirements

    NASA Technical Reports Server (NTRS)

    Vonglahn, U. H.; Groesbeck, D. E.

    1981-01-01

    Predicted engine core noise levels are compared with measured total aircraft noise levels and with current and proposed federal noise certification requirements. Comparisons are made at the FAR-36 measuring stations and include consideration of both full- and cutback-power operation at takeoff. In general, core noise provides a barrier to achieving proposed EPA stage 5 noise levels for all types of aircraft. More specifically, core noise levels will limit further reductions in aircraft noise levels for current widebody commercial aircraft.

  3. Failure Investigation of WB-57 Aircraft Engine Cowling

    NASA Technical Reports Server (NTRS)

    Martinez, J. E.; Gafka, T.; Figert, J.

    2014-01-01

    The NASA Johnson Space Center (JSC) in Houston, Texas is the home of the NASA WB-57 High Altitude Research Program. Three fully operational WB-57 aircraft are based near JSC at Ellington Field. The aircraft have been flying research missions since the early 1960's, and continue to be an asset to the scientific community with professional, reliable, customer-oriented service designed to meet all scientific objectives. The NASA WB-57 Program provides unique, high-altitude airborne platforms to US Government agencies, academic institutions, and commercial customers in order to support scientific research and advanced technology development and testing at locations around the world. Mission examples include atmospheric and earth science, ground mapping, cosmic dust collection, rocket launch support, and test bed operations for future airborne or spaceborne systems. During the return from a 6 hour flight, at 30,000 feet, in the clean configuration, traveling at 175 knots indicated airspeed, in un-accelerated flight with the auto pilot engaged, in calm air, the 2-man crew heard a mechanical bang and felt a slight shudder followed by a few seconds of high frequency vibration. The crew did not notice any other abnormalities leading up to, or for the remaining 1 hour of flight and made an uneventful landing. Upon taxi into the chocks, the recovery ground crew noticed the high frequency long wire antenna had become disconnected from the vertical stabilizer and was trailing over the left inboard wing, and that the left engine upper center removable cowling panel was missing, with noticeable damage to the left engine inboard cowling fixed structure. The missing cowling panel was never recovered. Each engine cowling panel is attached to the engine nacelle using six bushings made of 17-4 PH steel. The cylinder portions of four of the six bushings were found still attached to the aircraft (Fig 1). The other two bushings were lost with the panel. The other four bushings exhibited

  4. Engine balance apparatus and accessory drive device

    NASA Technical Reports Server (NTRS)

    Brogdon, James William (Inventor); Gill, David Keith (Inventor)

    2000-01-01

    A balancing mechanism for an engine that has a rotating crankshaft and reciprocating pistons such as those engines used in automobiles, aircrafts, boats, piston-driven compressors, piston-driven slider crank mechanisms, etc. The present balancing mechanism may comprise a first balance mass non-rotatably affixed to the crankshaft and a second balance mass rotatably supported on the crankshaft. A driver assembly is affixed to crankshaft to cause the second balance mass to rotate in a direction that is opposite to the direction in which the crank shaft is rotating. The driver assembly may include auxiliary gears configured to transport rotary power to auxiliary components.

  5. Energy efficient engine program contributions to aircraft fuel conservation

    NASA Technical Reports Server (NTRS)

    Batterton, P. G.

    1984-01-01

    Significant advances in high bypass turbofan technologies that enhance fuel efficiency have been demonstrated in the NASA Energy Efficient Engine Program. This highly successful second propulsion element of the NASA Aircraft Energy Efficiency Program included major contract efforts with both General Electric and Pratt & Whitney. Major results of these efforts will be presented including highlights from the NASA/General Electric E3 research turbofan engine test. Direct application of all the E3 technologies could result in fuel savings of over 18% compared to the CF6-50 and JT9D-7. Application of the E3 technologies to new and derivative engines such as the CF6-80C and PW 2037, as well as others, will be discussed. Significant portions of the fuel savings benefit for these new products can be directly related to the E3 technology program. Finally, results of a study looking at far term advanced turbofan engines will be briefly described. The study shows that substantial additional fuel savings over E3 are possible with additional turbofan technology programs.

  6. Proposed Rule and Related Materials for Control of Emissions of Air Pollution From Nonroad Diesel Engines Control of Air Pollution From Aircraft and Aircraft Engines; Proposed Emission Standards and Test Procedures

    EPA Pesticide Factsheets

    Proposed Rule and Related Materials for Control of Emissions of Air Pollution From Nonroad Diesel Engines Control of Air Pollution From Aircraft and Aircraft Engines; Proposed Emission Standards and Test Procedures

  7. 75 FR 28504 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ...) Perform a leak check as follows: (i) Clean the crankcase surface to remove any oil. (ii) Warm up the engine to a minimum oil temperature of 50 degrees C (120 degrees F). Information about warming up the... crankcase assembly S/N up to and including S/N 27811, certificated in any category: Type certificate...

  8. Adjustable expandable cryogenic piston and ring

    DOEpatents

    Mazur, Peter O.; Pallaver, Carl B.

    1980-01-01

    The operation of a reciprocating expansion engine for cryogenic refrigeration is improved by changing the pistons and rings so that the piston can be operated from outside the engine to vary the groove in which the piston ring is located. This causes the ring, which is of a flexible material, to be squeezed so that its contact with the wall is subject to external control. This control may be made manually or it may be made automatically in response to instruments that sense the amount of blow-by of the cryogenic fluid and adjust for an optimum blow-by.

  9. Analysis of the volatile organic matter of engine piston deposits by direct sample introduction thermal desorption gas chromatography/mass spectrometry.

    PubMed

    Diaby, M; Kinani, S; Genty, C; Bouchonnet, S; Sablier, M; Le Negrate, A; El Fassi, M

    2009-12-01

    This article establishes an alternative method for the characterization of volatiles organic matter (VOM) contained in deposits of the piston first ring grooves of diesel engines using a ChromatoProbe direct sample introduction (DSI) device coupled to gas chromatography/mass spectrometry (GC/MS) analysis. The addition of an organic solvent during thermal desorption leads to an efficient extraction and a good chromatographic separation of extracted products. The method was optimized investigating the effects of several solvents, the volume added to the solid sample, and temperature programming of the ChromatoProbe DSI device. The best results for thermal desorption were found using toluene as an extraction solvent and heating the programmable temperature injector from room temperature to 300 degrees C with a temperature step of 105 degrees C. With the use of the optimized thermal desorption conditions, several components have been positively identified in the volatile fraction of the deposits: aromatics, antioxidants, and antioxidant degradation products. Moreover, this work highlighted the presence of diesel fuel in the VOM of the piston deposits and gave new facts on the absence of the role of diesel fuel in the deposit formation process. Most importantly, it opens the possibility of quickly performing the analysis of deposits with small amounts of samples while having a good separation of the volatiles.

  10. Fatigue Lifetime Assessment of Aircraft Engine Disc via Multi-source Information Fusion

    NASA Astrophysics Data System (ADS)

    Huang, Hong-Zhong; Cui, Ping-Liang; Peng, Weiwen; Gao, Hui-Ying; Wang, Hai-Kun

    2014-06-01

    Fatigue lifetime assessment for aircraft engine discs is an important issue for the operation and health management of aircraft engines. Due to the lack of field test data, traditional methods can hardly meet the requirements of fatigue lifetime assessment of aircraft engine discs. By combining a multi-source information fusion method with a Bayesian inference technique, this paper develops a practical approach for fatigue lifetime assessment of aircraft engine discs. Subjective information and historical data are combined coherently with the sparse test data to generate a credible fatigue lifetime assessment of aircraft engine discs. Methods for quantifying subjective information, checking different experts' information, and fusing multiple prior distributions are presented to facilitate the implementation of fatigue lifetime assessment. An illustrative example is presented to demonstrate the procedures and the implication of the proposed method.

  11. An integrated systems engineering approach to aircraft design

    NASA Astrophysics Data System (ADS)

    Price, M.; Raghunathan, S.; Curran, R.

    2006-06-01

    The challenge in Aerospace Engineering, in the next two decades as set by Vision 2020, is to meet the targets of reduction of nitric oxide emission by 80%, carbon monoxide and carbon dioxide both by 50%, reduce noise by 50% and of course with reduced cost and improved safety. All this must be achieved with expected increase in capacity and demand. Such a challenge has to be in a background where the understanding of physics of flight has changed very little over the years and where industrial growth is driven primarily by cost rather than new technology. The way forward to meet the challenges is to introduce innovative technologies and develop an integrated, effective and efficient process for the life cycle design of aircraft, known as systems engineering (SE). SE is a holistic approach to a product that comprises several components. Customer specifications, conceptual design, risk analysis, functional analysis and architecture, physical architecture, design analysis and synthesis, and trade studies and optimisation, manufacturing, testing validation and verification, delivery, life cycle cost and management. Further, it involves interaction between traditional disciplines such as Aerodynamics, Structures and Flight Mechanics with people- and process-oriented disciplines such as Management, Manufacturing, and Technology Transfer. SE has become the state-of-the-art methodology for organising and managing aerospace production. However, like many well founded methodologies, it is more difficult to embody the core principles into formalised models and tools. The key contribution of the paper will be to review this formalisation and to present the very latest knowledge and technology that facilitates SE theory. Typically, research into SE provides a deeper understanding of the core principles and interactions, and helps one to appreciate the required technical architecture for fully exploiting it as a process, rather than a series of events. There are major issues as

  12. Piston and connecting rod assembly

    NASA Technical Reports Server (NTRS)

    Brogdon, James William (Inventor); Gill, David Keith (Inventor); Chatten, John K. (Inventor)

    2001-01-01

    A piston and connecting rod assembly includes a piston crown, a piston skirt, a connecting rod, and a bearing insert. The piston skirt is a component separate from the piston crown and is connected to the piston crown to provide a piston body. The bearing insert is a component separate from the piston crown and the piston skirt and is fixedly disposed within the piston body. A bearing surface of a connecting rod contacts the bearing insert to thereby movably associate the connecting rod and the piston body.

  13. Preliminary Training Proposal for Cessna Aircraft of Independence.

    ERIC Educational Resources Information Center

    Independence Community Coll., KS.

    This proposal for a program designed to train workers to manufacture single-engine, piston-driven aircraft for Cessna Corporation was developed by Independence Community College in conjunction with Pittsburgh State University (Kansas) and the Southeast Kansas Area Vocational-Technical School. The proposal provides for on-site training in a…

  14. Aircraft Turbine Engine Monitoring Systems: Overview and Lessons Learned from Six Case Studies

    DTIC Science & Technology

    1979-05-01

    engines of both groups. EHMS (T-38 / J85 ) ACTIVITY OUTCOMES JULY 󈨐 - MAY 󈨑 INSIRUMENTED ENGINES CONTROL ENGINES NUMBER OF ENGINES 26 26 TOTAL...Kreviews the experience gained from several aircraft turbine engine monitoring systems used over the last decade and a half and examines the...the supporting research. -,Two different approaches to engine monitoring have evolved in attempts to achieve the goals of improved engine operations

  15. Real-time measurements of jet aircraft engine exhaust.

    PubMed

    Rogers, Fred; Arnott, Pat; Zielinska, Barbara; Sagebiel, John; Kelly, Kerry E; Wagner, David; Lighty, JoAnn S; Sarofim, Adel F

    2005-05-01

    Particulate-phase exhaust properties from two different types of ground-based jet aircraft engines--high-thrust and turboshaft--were studied with real-time instruments on a portable pallet and additional time-integrated sampling devices. The real-time instruments successfully characterized rapidly changing particulate mass, light absorption, and polycyclic aromatic hydrocarbon (PAH) content. The integrated measurements included particulate-size distributions, PAH, and carbon concentrations for an entire test run (i.e., "run-integrated" measurements). In all cases, the particle-size distributions showed single modes peaking at 20-40nm diameter. Measurements of exhaust from high-thrust F404 engines showed relatively low-light absorption compared with exhaust from a turboshaft engine. Particulate-phase PAH measurements generally varied in phase with both net particulate mass and with light-absorbing particulate concentrations. Unexplained response behavior sometimes occurred with the real-time PAH analyzer, although on average the real-time and integrated PAH methods agreed within the same order of magnitude found in earlier investigations.

  16. Performance of Several Combustion Chambers Designed for Aircraft Oil Engines

    NASA Technical Reports Server (NTRS)

    Joachim, William F; Kemper, Carlton

    1928-01-01

    Several investigations have been made on single-cylinder test engines to determine the performance characteristics of four types of combustion chambers designed for aircraft oil engines. Two of the combustion chambers studied were bulb-type precombustion chambers, the connecting orifice of one having been designed to produce high turbulence by tangential air flow in both the precombustion chamber and the cylinder. The other two were integral combustion chambers, one being dome-shaped and the other pent-roof shaped. The injection systems used included cam and eccentric driven fuel pumps, and diaphragm and spring-loaded fuel-injection valves. A diaphragm type maximum cylinder pressure indicator was used in part of these investigations with which the cylinder pressures were controlled to definite valves. The performance of the engines when equipped with each of the combustion chambers is discussed. The best performance for the tests reported was obtained with a bulb-type combustion chamber designed to give a high degree of turbulence within the bulb and cylinder. (author)

  17. ADAM: An Axisymmetric Duct Aeroacoustic Modeling system. [aircraft turbofan engines

    NASA Technical Reports Server (NTRS)

    Abrahamson, A. L.

    1983-01-01

    An interconnected system of computer programs for analyzing the propagation and attenuation of sound in aeroengine ducts containing realistic compressible subsonic mean flows, ADAM was developed primarily for research directed towards the reduction of noise emitted from turbofan aircraft engines. The two basic components are a streamtube curvature program for determination of the mean flow, and a finite element code for solution of the acoustic propagation problem. The system, which has been specifically tailored for ease of use, is presently installed at NASA Langley Reseach Center on a Control Data Cyber 175 Computer under the NOS Operating system employing a Tektronix terminal for interactive graphics. The scope and organization of the ADAM system is described. A users guide, examples of input data, and results for selected cases are included.

  18. Aircraft engine with inter-turbine engine frame supported counter rotating low pressure turbine rotors

    NASA Technical Reports Server (NTRS)

    Seda, Jorge F. (Inventor); Dunbar, Lawrence W. (Inventor); Gliebe, Philip R. (Inventor); Szucs, Peter N. (Inventor); Brauer, John C. (Inventor); Johnson, James E. (Inventor); Moniz, Thomas (Inventor); Steinmetz, Gregory T. (Inventor)

    2003-01-01

    An aircraft gas turbine engine assembly includes an inter-turbine frame axially located between high and low pressure turbines. Low pressure turbine has counter rotating low pressure inner and outer rotors with low pressure inner and outer shafts which are at least in part rotatably disposed co-axially within a high pressure rotor. Inter-turbine frame includes radially spaced apart radially outer first and inner second structural rings disposed co-axially about a centerline and connected by a plurality of circumferentially spaced apart struts. Forward and aft sump members having forward and aft central bores are fixedly joined to axially spaced apart forward and aft portions of the inter-turbine frame. Low pressure inner and outer rotors are rotatably supported by a second turbine frame bearing mounted in aft central bore of aft sump member. A mount for connecting the engine to an aircraft is located on first structural ring.

  19. Engine Performance and Knock Rating of Fuels for High-output Aircraft Engines

    NASA Technical Reports Server (NTRS)

    Rothbrock, A M; Biermann, Arnold E

    1938-01-01

    Data are presented to show the effects of inlet-air pressure, inlet-air temperature, and compression ratio on the maximum permissible performance obtained on a single-cylinder test engine with aircraft-engine fuels varying from a fuel of 87 octane number to one 100 octane number plus 1 ml of tetraethyl lead per gallon. The data were obtained on a 5-inch by 5.75-inch liquid-cooled engine operating at 2,500 r.p.m. The compression ratio was varied from 6.50 to 8.75. The inlet-air temperature was varied from 120 to 280 F. and the inlet-air pressure from 30 inches of mercury absolute to the highest permissible. The limiting factors for the increase in compression ratio and in inlet-air pressure was the occurrence of either audible or incipient knock. The data are correlated to show that, for any one fuel,there is a definite relationship between the limiting conditions of inlet-air temperature and density at any compression ratio. This relationship is dependent on the combustion-gas temperature and density relationship that causes knock. The report presents a suggested method of rating aircraft-engine fuels based on this relationship. It is concluded that aircraft-engine fuels cannot be satisfactorily rated by any single factor, such as octane number, highest useful compression ratio, or allowable boost pressure. The fuels should be rated by a curve that expresses the limitations of the fuel over a variety of engine conditions.

  20. Investigation of a 7-pole/6-slot Halbach-magnetized permanent-magnet linear alternator used for free-piston stirling engines

    NASA Astrophysics Data System (ADS)

    Zheng, Ping; Tong, Chengde; Zhao, Jing; Yu, Bin; Li, Lin; Bai, Jingang; Zhang, Lu

    2012-04-01

    This paper investigates a 7-pole/6-slot Halbach-magnetized permanent-magnet linear alternator used for free piston Stirling engines (FPSEs). Taking the advantages of Halbach array, a 1 kW prototype alternator is designed. Considering the rms value of electromotive force (EMF) and harmonic distortion, the optimal length ratio of the axial- and radial-magnetized permanent magnets and thicknesses of the permanent magnets are optimized by 2D finite element method. The alternator detent force, which is an important factor for smooth operation of FPSEs, is studied by optimizing slot tip and end tooth. The load and thermal performances of the final design are simulated. A prototype alternator was designed, built and tested. Experimental data indicated satisfactory design.

  1. Adaptive Failure Compensation for Aircraft Flight Control Using Engine Differentials: Regulation

    NASA Technical Reports Server (NTRS)

    Yu, Liu; Xidong, Tang; Gang, Tao; Joshi, Suresh M.

    2005-01-01

    The problem of using engine thrust differentials to compensate for rudder and aileron failures in aircraft flight control is addressed in this paper in a new framework. A nonlinear aircraft model that incorporates engine di erentials in the dynamic equations is employed and linearized to describe the aircraft s longitudinal and lateral motion. In this model two engine thrusts of an aircraft can be adjusted independently so as to provide the control flexibility for rudder or aileron failure compensation. A direct adaptive compensation scheme for asymptotic regulation is developed to handle uncertain actuator failures in the linearized system. A design condition is specified to characterize the system redundancy needed for failure compensation. The adaptive regulation control scheme is applied to the linearized model of a large transport aircraft in which the longitudinal and lateral motions are coupled as the result of using engine thrust differentials. Simulation results are presented to demonstrate the effectiveness of the adaptive compensation scheme.

  2. Lightweight piston architecture

    NASA Technical Reports Server (NTRS)

    Taylor, Allan H. (Inventor); Ransone, Philip O. (Inventor)

    1990-01-01

    The invention is an improvement in a lightweight carbon-carbon composite piston, the improvement uses near-net shape knitted or warp-interlock preforms to improve the structural qualities of the piston. In its preferred embodiment, a one piece, tubular, closed-ended, knitted preform (a sock) of carbon fibers embedded within the matrix of the piston structure forms the crown, side wall, skirt and inner surface of the piston, and wrap-interlock preforms strengthen the piston crown and wrist pin bosses.

  3. Role of structural noise in aircraft pressure cockpit from vibration action of new-generation engines

    NASA Astrophysics Data System (ADS)

    Baklanov, V. S.

    2016-07-01

    The evolution of new-generation aircraft engines is transitioning from a bypass ratio of 4-6 to an increased ratio of 8-12. This is leading to substantial broadening of the vibration spectrum of engines with a shift to the low-frequency range due to decreased rotation speed of the fan rotor, in turn requiring new solutions to decrease structural noise from engine vibrations to ensure comfort in the cockpits and cabins of aircraft.

  4. Modern design methodology and problems in training aircraft engineers

    NASA Technical Reports Server (NTRS)

    Liseitsev, N. K.

    1989-01-01

    A brief report on the problem of modern aircraft specialist education is presented that is devoted to the content and methods of teaching a course in General Aircraft Design in the Moscow Aviation Institute.

  5. Boundary layer effects on liners for aircraft engines

    NASA Astrophysics Data System (ADS)

    Gabard, Gwénaël

    2016-10-01

    The performance of acoustic treatments installed on aircraft engines is strongly influenced by the boundary layer of the grazing flow on the surface of the liner. The parametric study presented in this paper illustrates the extent of this effect and identifies when it is significant. The acoustic modes of a circular duct with flow are calculated using a finite difference method. The parameters are representative of the flow conditions, liners and sound fields found in current turbofan engines. Both the intake and bypass ducts are considered. Results show that there is a complex interplay between the boundary layer thickness, the direction of propagation and the liner impedance and that the boundary layer can have a strong impact on liner performance for typical configurations (including changes of the order of 30 dB on the attenuation of modes associated with tonal fan noise). A modified impedance condition including the effect of a small but finite boundary layer thickness is considered and compared to the standard Myers condition based on an infinitely thin boundary layer. We show how this impedance condition can be implemented in a mode calculation method by introducing auxiliary variables. This condition is able to capture the trends associated with the boundary layer effects and in most cases provides improved predictions of liner performance.

  6. Small Internal Combustion Engine Testing for a Hybrid-Electric Remotely-Piloted Aircraft

    DTIC Science & Technology

    2011-03-01

    means of a connecting rod. The linear motion of the piston is translated into rotational motion through the connection between crankshaft and connecting...aligned in a V-shape which is well balanced and linearly compact. Six and eight cylinder engines are also commonly arranged in a linear or straight... apparatus . Power is calculated from torque and angular speed measurements by means of Equation 3. 2 3 Power is most often expressed in units of kW

  7. Small Engine Technology (SET) Task 24 Business and Regional Aircraft System Studies

    NASA Technical Reports Server (NTRS)

    Lieber, Lysbeth

    2003-01-01

    This final report has been prepared by Honeywell Engines & Systems, Phoenix, Arizona, a unit of Honeywell International Inc., documenting work performed during the period June 1999 through December 1999 for the National Aeronautics and Space Administration (NASA) Glenn Research Center, Cleveland, Ohio, under the Small Engine Technology (SET) Program, Contract No. NAS3-27483, Task Order 24, Business and Regional Aircraft System Studies. The work performed under SET Task 24 consisted of evaluating the noise reduction benefits compared to the baseline noise levels of representative 1992 technology aircraft, obtained by applying different combinations of noise reduction technologies to five business and regional aircraft configurations. This report focuses on the selection of the aircraft configurations and noise reduction technologies, the prediction of noise levels for those aircraft, and the comparison of the noise levels with those of the baseline aircraft.

  8. Data Fusion for Enhanced Aircraft Engine Prognostics and Health Management

    NASA Technical Reports Server (NTRS)

    Volponi, Al

    2005-01-01

    Aircraft gas-turbine engine data is available from a variety of sources, including on-board sensor measurements, maintenance histories, and component models. An ultimate goal of Propulsion Health Management (PHM) is to maximize the amount of meaningful information that can be extracted from disparate data sources to obtain comprehensive diagnostic and prognostic knowledge regarding the health of the engine. Data fusion is the integration of data or information from multiple sources for the achievement of improved accuracy and more specific inferences than can be obtained from the use of a single sensor alone. The basic tenet underlying the data/ information fusion concept is to leverage all available information to enhance diagnostic visibility, increase diagnostic reliability and reduce the number of diagnostic false alarms. This report describes a basic PHM data fusion architecture being developed in alignment with the NASA C-17 PHM Flight Test program. The challenge of how to maximize the meaningful information extracted from disparate data sources to obtain enhanced diagnostic and prognostic information regarding the health and condition of the engine is the primary goal of this endeavor. To address this challenge, NASA Glenn Research Center, NASA Dryden Flight Research Center, and Pratt & Whitney have formed a team with several small innovative technology companies to plan and conduct a research project in the area of data fusion, as it applies to PHM. Methodologies being developed and evaluated have been drawn from a wide range of areas including artificial intelligence, pattern recognition, statistical estimation, and fuzzy logic. This report will provide a chronology and summary of the work accomplished under this research contract.

  9. Differences in Characteristics of Aviation Accidents During 1993-2012 Based on Aircraft Type

    NASA Technical Reports Server (NTRS)

    Evans, Joni K.

    2015-01-01

    Civilian aircraft are available in a variety of sizes, engine types, construction materials and instrumentation complexity. For the analysis reported here, eleven aircraft categories were developed based mostly on aircraft size and engine type, and these categories were applied to twenty consecutive years of civil aviation accidents. Differences in various factors were examined among these aircraft types, including accident severity, pilot characteristics and accident occurrence categories. In general, regional jets and very light sport aircraft had the lowest rates of adverse outcomes (injuries, fatal accidents, aircraft destruction, major accidents), while aircraft with twin (piston) engines or with a single (piston) engine and retractable landing gear carried the highest incidence of adverse outcomes. The accident categories of abnormal runway contact, runway excursions and non-powerplant system/component failures occur frequently within all but two or three aircraft types. In contrast, ground collisions, loss of control - on ground/water and powerplant system/component failure occur frequently within only one or two aircraft types. Although accidents in larger aircraft tend to have less severe outcomes, adverse outcome rates also differ among accident categories. It may be that the type of accident has as much or more influence on the outcome as the type of aircraft.

  10. Ceramics Technology Project database: September 1991 summary report. [Materials for piston ring-cylinder liner for advanced heat/diesel engines

    SciTech Connect

    Keyes, B.L.P.

    1992-06-01

    The piston ring-cylinder liner area of the internal combustion engine must withstand very-high-temperature gradients, highly-corrosive environments, and constant friction. Improving the efficiency in the engine requires ring and cylinder liner materials that can survive this abusive environment and lubricants that resist decomposition at elevated temperatures. Wear and friction tests have been done on many material combinations in environments similar to actual use to find the right materials for the situation. This report covers tribology information produced from 1986 through July 1991 by Battelle columbus Laboratories, Caterpillar Inc., and Cummins Engine Company, Inc. for the Ceramic Technology Project (CTP). All data in this report were taken from the project's semiannual and bimonthly progress reports and cover base materials, coatings, and lubricants. The data, including test rig descriptions and material characterizations, are stored in the CTP database and are available to all project participants on request. Objective of this report is to make available the test results from these studies, but not to draw conclusions from these data.

  11. Development potential of Intermittent Combustion (I.C.) aircraft engines for commuter transport applications

    NASA Technical Reports Server (NTRS)

    Willis, E. A.

    1982-01-01

    An update on general aviation (g/a) and commuter aircraft propulsion research effort is reviewed. The following topics are discussed: on several advanced intermittent combustion engines emphasizing lightweight diesels and rotary stratified charge engines. The current state-of-the-art is evaluated for lightweight, aircraft suitable versions of each engine. This information is used to project the engine characteristics that can be expected on near-term and long-term time horizons. The key enabling technology requirements are identified for each engine on the long-term time horizon.

  12. Price-Weight Relationships of General Aviation, Helicopters, Transport Aircraft and Engines

    NASA Technical Reports Server (NTRS)

    Anderson, Joseph L.

    1981-01-01

    The NASA must assess its aeronautical research program with economic as well as performance measures. It thus is interested in what price a new technology aircraft would carry to make it attractive to the buyer. But what price a given airplane or helicopter will carry is largely a reflection of the manufacturer's assessment of the competitive market into which the new aircraft will be introduced. The manufacturer must weigh any new aerodynamic or system technology innovation he would add to an aircraft by the impact of this innovation upon the aircraft's cost to manufacture, economic attractiveness and price. The intent of this paper is to give price standards against which new technologies and the NASA's research program can be assessed. Using reported prices for sailplanes, general aviation, agriculture, helicopter, business and transport aircraft, price estimating relations in terms of engine and airframe characteristics have been developed. The relations are given in terms of the aircraft type, its manufactured empty weight, engine weight, horsepower or thrust. Factors for the effects of inflation are included to aid in making predictions of future aircraft prices. There are discussions of aircraft price in terms of number of passenger seats, airplane size and research and development costs related to an aircraft model, and indirectly how new technologies, aircraft complexity and inflation have affected these.

  13. Layered clustering multi-fault diagnosis for hydraulic piston pump

    NASA Astrophysics Data System (ADS)

    Du, Jun; Wang, Shaoping; Zhang, Haiyan

    2013-04-01

    Efficient diagnosis is very important for improving reliability and performance of aircraft hydraulic piston pump, and it is one of the key technologies in prognostic and health management system. In practice, due to harsh working environment and heavy working loads, multiple faults of an aircraft hydraulic pump may occur simultaneously after long time operations. However, most existing diagnosis methods can only distinguish pump faults that occur individually. Therefore, new method needs to be developed to realize effective diagnosis of simultaneous multiple faults on aircraft hydraulic pump. In this paper, a new method based on the layered clustering algorithm is proposed to diagnose multiple faults of an aircraft hydraulic pump that occur simultaneously. The intensive failure mechanism analyses of the five main types of faults are carried out, and based on these analyses the optimal combination and layout of diagnostic sensors is attained. The three layered diagnosis reasoning engine is designed according to the faults' risk priority number and the characteristics of different fault feature extraction methods. The most serious failures are first distinguished with the individual signal processing. To the desultory faults, i.e., swash plate eccentricity and incremental clearance increases between piston and slipper, the clustering diagnosis algorithm based on the statistical average relative power difference (ARPD) is proposed. By effectively enhancing the fault features of these two faults, the ARPDs calculated from vibration signals are employed to complete the hypothesis testing. The ARPDs of the different faults follow different probability distributions. Compared with the classical fast Fourier transform-based spectrum diagnosis method, the experimental results demonstrate that the proposed algorithm can diagnose the multiple faults, which occur synchronously, with higher precision and reliability.

  14. Computer code for estimating installed performance of aircraft gas turbine engines. Volume 2: Users manual

    NASA Technical Reports Server (NTRS)

    Kowalski, E. J.

    1979-01-01

    A computerized method which utilizes the engine performance data and estimates the installed performance of aircraft gas turbine engines is presented. This installation includes: engine weight and dimensions, inlet and nozzle internal performance and drag, inlet and nacelle weight, and nacelle drag. A user oriented description of the program input requirements, program output, deck setup, and operating instructions is presented.

  15. Computer code for estimating installed performance of aircraft gas turbine engines. Volume 1: Final report

    NASA Technical Reports Server (NTRS)

    Kowalski, E. J.

    1979-01-01

    A computerized method which utilizes the engine performance data is described. The method estimates the installed performance of aircraft gas turbine engines. This installation includes: engine weight and dimensions, inlet and nozzle internal performance and drag, inlet and nacelle weight, and nacelle drag.

  16. Pollution reduction technology program for small jet aircraft engines: Class T1

    NASA Technical Reports Server (NTRS)

    Bruce, T. W.; Davis, F. G.; Mongia, H. C.

    1977-01-01

    Small jet aircraft engines (EPA class T1, turbojet and turbofan engines of less than 35.6 kN thrust) were evaluated with the objective of attaining emissions reduction consistent with performance constraints. Configurations employing the technological advances were screened and developed through full scale rig testing. The most promising approaches in full-scale engine testing were evaluated.

  17. The Role of Modern Control Theory in the Design of Controls for Aircraft Turbine Engines

    NASA Technical Reports Server (NTRS)

    Zeller, J.; Lehtinen, B.; Merrill, W.

    1982-01-01

    Accomplishments in applying Modern Control Theory to the design of controls for advanced aircraft turbine engines were reviewed. The results of successful research programs are discussed. Ongoing programs as well as planned or recommended future thrusts are also discussed.

  18. Study of aerodynamic technology for single-cruise-engine VSTOL fighter/attack aircraft, phase 1

    NASA Technical Reports Server (NTRS)

    Foley, W. H.; Sheridan, A. E.; Smith, C. W.

    1982-01-01

    A conceptual design and analysis on a single engine VSTOL fighter/attack aircraft is completed. The aircraft combines a NASA/deHavilland ejector with vectored thrust and is capable of accomplishing the mission and point performance of type Specification 169, and a flight demonstrator could be built with an existing F101/DFE engine. The aerodynamic, aero/propulsive, and propulsive uncertainties are identified, and a wind tunnel program is proposed to address those uncertainties associated with wing borne flight.

  19. Results and status of the NASA aircraft engine emission reduction technology programs

    NASA Technical Reports Server (NTRS)

    Jones, R. E.; Diehl, L. A.; Petrash, D. A.; Grobman, J.

    1978-01-01

    The results of an aircraft engine emission reduction study are reviewed in detail. The capability of combustor concepts to produce significantly lower levels of exhaust emissions than present production combustors was evaluated. The development status of each combustor concept is discussed relative to its potential for implementation in aircraft engines. Also, the ability of these combustor concepts to achieve proposed NME and NCE EPA standards is discussed.

  20. Fault mechanism analysis and simulation for continuity resistance test of electrical components in aircraft engine

    NASA Astrophysics Data System (ADS)

    Shi, Xudong; Yin, Yaping; Wang, Jialin; Sun, Zhaorong

    2017-01-01

    A large number of electrical components are used in civil aircraft engines, whose electrical circuits are usually intricate and complicated. Continuity resistance is an important parameter for the operating state of electrical components. Electrical continuity fault has serious impact on the reliability of the aircraft engine. In this paper, mathematical models of electrical components are established, and simulation is made by Simulink to analyze the electrical continuity fault.

  1. Jet aircraft engine exhaust emissions database development: Year 1990 and 2015 scenarios

    NASA Technical Reports Server (NTRS)

    Landau, Z. Harry; Metwally, Munir; Vanalstyne, Richard; Ward, Clay A.

    1994-01-01

    Studies relating to environmental emissions associated with the High Speed Civil Transport (HSCT) military jet and charter jet aircraft were conducted by McDonnell Douglas Aerospace Transport Aircraft. The report includes engine emission results for baseline 1990 charter and military scenario and the projected jet engine emissions results for a 2015 scenario for a Mach 1.6 HSCT charter and military fleet. Discussions of the methodology used in formulating these databases are provided.

  2. Physical characterization of the fine particle emissions from commercial aircraft engines during the Aircraft Particle Emissions Experiment (APEX) 1 to 3

    EPA Science Inventory

    The f1me particulate matter (PM) emissions from nine commercial aircraft engine models were determined by plume sampling during the three field campaigns of the Aircraft Particle Emissions Experiment (APEX). Ground-based measurements were made primarily at 30 m behind the engine ...

  3. An inventory of particle and gaseous emissions from large aircraft thrust engine operations at an airport

    NASA Astrophysics Data System (ADS)

    Mazaheri, M.; Johnson, G. R.; Morawska, L.

    2011-07-01

    Published particle number emission factors for aircraft operations remain very sparse and so far such emissions have not been included in the International Civil Aviation Organization (ICAO) databases. This work addresses this gap in knowledge by utilizing recent progress in the quantification of aircraft particle emissions. Annual emissions of particle number (PN), particle mass (PM 2.5) and NO x throughout the aircraft landing and takeoff (LTO) cycles and ground running procedures (GRP) are presented for aircraft using Brisbane Airport BNE (domestic and international). The aircraft are grouped according to an airframe based classification system. The resulting data are then used to develop an emissions inventory for large aircraft thrust engine operations on the ground, during LTO cycles and GRP, at the Airport. Annual PN, PM 2.5 and NO x emissions from large aircraft operations during LTO cycles and GRP at BNE were 1.98 × 10 24 yr -1, 1.35 × 10 4 kg yr -1 and 8.13 × 10 5 kg yr -1, respectively. Results showed that LTO cycles contribute more than 97% of these annual emissions at BNE in comparison to GRP related emissions. Analysis of the LTO cycle contribution to the daily emissions showed that the contribution of the climbout mode is considerably higher than for other individual LTO operational modes. Emissions during aircraft departures were significantly higher than those during arrival operations, due to the higher aircraft engine emission rates during takeoff and climbout.

  4. Adaptive Failure Compensation for Aircraft Tracking Control Using Engine Differential Based Model

    NASA Technical Reports Server (NTRS)

    Liu, Yu; Tang, Xidong; Tao, Gang; Joshi, Suresh M.

    2006-01-01

    An aircraft model that incorporates independently adjustable engine throttles and ailerons is employed to develop an adaptive control scheme in the presence of actuator failures. This model captures the key features of aircraft flight dynamics when in the engine differential mode. Based on this model an adaptive feedback control scheme for asymptotic state tracking is developed and applied to a transport aircraft model in the presence of two types of failures during operation, rudder failure and aileron failure. Simulation results are presented to demonstrate the adaptive failure compensation scheme.

  5. Free piston space Stirling technology program

    NASA Technical Reports Server (NTRS)

    Dochat, G. R.; Dhar, M.

    1989-01-01

    MTI recently completed an initial technology feasibility program for NASA by designing, fabricating and testing a space power demonstrator engine (SPDE). This program, which confirms the potential of free-piston Stirling engines, provided the major impetus to initiate a free-piston Stirling space engine (SSE) technology program. The accomplishments of the SPDE program are reviewed, and an overview of the SSE technology program and technical status to date is provided. It is shown that progress in both programs continues to justify its potential for either nuclear or solar space power missions.

  6. 14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... data approved by the Administrator. (e) The holder of an air carrier operating certificate or an... holder of a repairman certificate (light-sport aircraft) with a maintenance rating may approve an aircraft issued a special airworthiness certificate in light-sport category for return to service,...

  7. Engineering and Technical Configuration Aspects of HIAPER, the new NSF/NCAR Research Aircraft

    NASA Astrophysics Data System (ADS)

    Friesen, R.; Laursen, K.

    2002-12-01

    The High-performance Instrumented Airborne Platform for Environmental Research, or HIAPER, is the new research aircraft presently being developed at the National Center for Atmospheric Research (NCAR) to serve the environmental research needs of the National Science Foundation (NSF) for the next several decades. The basic aircraft -- a Gulfstream V (G-V) business jet -- has been completed and will shortly undergo extensive modification to prepare it for future deployments in support of a variety of geosciences research missions. This presentation will focus on the many design and engineering considerations that have been made and are yet to come in converting a "green" business jet into a versatile research aircraft to serve the environmental research community. The project teams composed of engineers and scientists from NCAR and the scientific community at large are faced with trade offs involving costs of modifications, airframe structural integrity, aircraft performance (e.g. weight, drag), cabin environment, locations of inlet and sampling ports and FAA certification requirements. Many of the specific engineering specifications and modifications that have been made to date will be presented by way of engineering drawings, graphical depictions and actual photographs of the aircraft structure. Additionally, projected performance data of the modified-for-research aircraft will be presented along with some of the analyses performed to arrive at critical decisions (e.g. CFD airflow analysis). Finally, some of the details of the aircraft "infrastructure" such as signal and power wiring, generic cabin layout and data acquisition will be discussed.

  8. Emissions and Total Energy Consumption of a Multicylinder Piston Engine Running on Gasoline and a Hydrogen-gasoline Mixture

    NASA Technical Reports Server (NTRS)

    Cassidy, J. F.

    1977-01-01

    A multicylinder reciprocating engine was used to extend the efficient lean operating range of gasoline by adding hydrogen. Both bottled hydrogen and hydrogen produced by a research methanol steam reformer were used. These results were compared with results for all gasoline. A high-compression-ratio, displacement production engine was used. Apparent flame speed was used to describe the differences in emissions and performance. Therefore, engine emissions and performance, including apparent flame speed and energy lost to the cooling system and the exhaust gas, were measured over a range of equivalence ratios for each fuel. All emission levels decreased at the leaner conditions. Adding hydrogen significantly increased flame speed over all equivalence ratios.

  9. Maritime Patrol Aircraft Engine Study P&WA Derivative Engines. Volume II. Performance Data.

    DTIC Science & Technology

    1979-04-30

    U) APR 79 R C NEWELL. P W HERRICK N62269-78C-0GIG UNCLASSIFIED PWA -FR-10966B/C"VOL-2 NAC-79132-60-VOL-2 NL mmEhE mhm 111 1 4;.c~ 111128 12.5 IIIIIII...MARITIME PATROL AIRCRAFT ENGINE STUDT PIWA DERIVATIVE ENGINES. --EC(U) APR 79 R C NEWELL. P W HERRICK N62269-78-C-010 UNCLASSIFIED PWA -FR-10966B/C-VOL-2 NADC...0.80 823. n. 524 -165. 51.3 5.8 1635. MAX .LIft 5.000. 0.85 6289 o 0.333 249. 125.3 17.*6 2535. MAX CKUISE 45000. 0.85 5629. 0.331 150.. 11,.6 16.3

  10. Linkage arms for minimizing piston wobble

    SciTech Connect

    Langstroth, S.W.

    1992-07-28

    This patent describes an internal combustion engine having a block within which at least one piston is attached to a crankshaft by a connecting rod between the crankpin of the crankshaft and the wrist pin of the piston. This patent describes improvement in a fixed gear concentric with the axis of the crankshaft and coupled to the block; a follower gear concentric with the crankpin; at least one intermediate gear coupling the fixed gear to the follower gear; wherein the ratio of the gears is such that the follower gear orbits the fixed gear and does not rotate; and linkage arms interconnecting the follower gear and the piston for preventing the rotation of the piston about the wrist pin.

  11. Engine-induced structural-borne noise in a general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Unruh, J. F.; Scheidt, D. C.; Pomerening, D. J.

    1979-01-01

    Structural borne interior noise in a single engine general aviation aircraft was studied to determine the importance of engine induced structural borne noise and to determine the necessary modeling requirements for the prediction of structural borne interior noise. Engine attached/detached ground test data show that engine induced structural borne noise is a primary interior noise source for the single engine test aircraft, cabin noise is highly influenced by responses at the propeller tone, and cabin acoustic resonances can influence overall noise levels. Results from structural and acoustic finite element coupled models of the test aircraft show that wall flexibility has a strong influence on fundamental cabin acoustic resonances, the lightweight fuselage structure has a high modal density, and finite element analysis procedures are appropriate for the prediction of structural borne noise.

  12. Effect of broadened-specification fuels on aircraft engines and fuel systems

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1979-01-01

    A wide variety of studies on the potential effects of broadened-specification fuels on future aircraft engines and fuel systems are summarized. The compositions and characteristics of aircraft fuels that may be derived from current and future crude-oil sources are described, and the most critical properties that may effect aircraft engines and fuel systems are identified and discussed. The problems that are most likely to be encountered because of changes in selected fuel properties are explored; and the related effects on engine performance, component durability and maintenance, and aircraft fuel-system performance are examined. The ability of current technology to accept possible future fuel specification changes is assessed and selected technological advances that can reduce the severity of the potential problems are illustrated.

  13. Determination and Applications of Environmental Costs at Different Sized Airports: Aircraft Noise and Engine Emissions

    NASA Technical Reports Server (NTRS)

    Lu, Cherie; Lierens, Abigail

    2003-01-01

    With the increasing trend of charging for externalities and the aim of encouraging the sustainable development of the air transport industry, there is a need to evaluate the social costs of these undesirable side effects, mainly aircraft noise and engine emissions, for different airports. The aircraft noise and engine emissions social costs are calculated in monetary terms for five different airports, ranging from hub airports to small regional airports. The number of residences within different levels of airport noise contours and the aircraft noise classifications are the main determinants for accessing aircraft noise social costs. Whist, based on the damages of different engine pollutants on the human health, vegetation, materials, aquatic ecosystem and climate, the aircraft engine emissions social costs vary from engine types to aircraft categories. The results indicate that the relationship appears to be curvilinear between environmental costs and the traffic volume of an airport. The results and methodology of environmental cost calculation could input for to the proposed European wide harmonized noise charges as well as the social cost benefit analysis of airports.

  14. Lightweight two-stroke cycle aircraft diesel engine technology enablement program, volume 3

    NASA Technical Reports Server (NTRS)

    Freen, P. D.; Berenyi, S. G.; Brouwers, A. P.; Moynihan, M. E.

    1985-01-01

    An experimental Single Cylinder Test Engine Program is conducted to confirm the analytically projected performance of a two-stroke cycle diesel engine for aircraft applications. Testing confirms the ability of a proposed 4-cylinder version of such an engine to reach the target power at altitude in a highly turbocharged configuration. The experimental program defines all necessary parameters to permit design of a multicylinder engine for eventual flight applications.

  15. Advanced liquid-cooled, turbocharged and intercooled stratified charge rotary engines for aircraft

    NASA Technical Reports Server (NTRS)

    Mount, Robert E.; Bartel, John; Hady, William F.

    1987-01-01

    Developments concerning stratified-charge rotary (SCR) engines over the past 10 years are reviewed. Aircraft engines being developed using SCR technology are shown and described, and the ability of such technology to meet general aviation engine needs is considered. Production timing and availability of SCR technology for the development of aviation rotary engines are discussed, and continuing efforts toward improving this technology, including NASA efforts, are described.

  16. Lightweight two-stroke cycle aircraft diesel engine technology enablement program, volume 2

    NASA Technical Reports Server (NTRS)

    Freen, P. D.; Berenyi, S. G.; Brouwers, A. P.; Moynihan, M. E.

    1985-01-01

    An experimental Single Cylinder Test Engine Program is conducted to confirm the analytically projected performance of a two-stroke cycle diesel engine for aircraft applications. Testing confirms the ability of a proposed 4-cylinder version of such an engine to reach the target power at altitude in a highly turbocharged configuration. The experimental program defines all necessary parameters to permit a design of a multicylinder engine for eventual flight applications.

  17. Thermodynamic efficiency of present types of internal combustion engines for aircraft

    NASA Technical Reports Server (NTRS)

    Lucke, Charles E

    1917-01-01

    Report presents requirements of internal combustion engines suitable for aircraft. Topics include: (1) service requirements for aeronautic engines - power versus weight, reliability, and adaptability factors, (2) general characteristics of present aero engines, (3) aero engine processes and functions of parts versus power-weight ratio, reliability, and adaptability factors, and (4) general arrangement, form, proportions, and materials of aero parts - power-weight ratio, reliability, and adaptability.

  18. Results of T56 Engine Performance Monitoring Trial in Hercules Aircraft, February-July 1977.

    DTIC Science & Technology

    1981-04-01

    Engine Removals/Rejections 2 3.1.1 Resume 5 3.2 Faults not Associated with Engine Removals 5 * NOTATION REFERENCES I TABLES FIGURES APPENDIX 1 ANNEX A...in those cases in which performance monitoring could have been expected to reflect the fault , the appropriate engine performance trend plots were...the appropriate EL 500. (ihis form is used by aircrew and maiintenazice personnel to record any aircraft/ engine fault and its subsequent

  19. Free piston inertia compressor

    DOEpatents

    Richards, William D. C.; Bilodeau, Denis; Marusak, Thomas; Dutram, Jr., Leonard; Brady, Joseph

    1981-01-01

    A free piston inertia compressor comprises a piston assembly including a connecting rod having pistons on both ends, the cylinder being split into two substantially identical portions by a seal through which the connecting rod passes. Vents in the cylinder wall are provided near the seal to permit gas to excape the cylinder until the piston covers the vent whereupon the remaining gas in the cylinder functions as a gas spring and cushions the piston against impact on the seal. The connecting rod has a central portion of relatively small diameter providing free play of the connecting rod through the seal and end portions of relatively large diameter providing a limited tolerance between the connecting rod and the seal. Finally, the seal comprises a seal ring assembly consisting of a dampener plate, a free floating seal at the center of the dampener plate and a seal retainer plate in one face of the dampener plate.

  20. Free piston inertia compressor

    DOEpatents

    Richards, W.D.C.; Bilodeau, D.; Marusak, T.; Dutram, L. Jr.; Brady, J.

    A free piston inertia compressor comprises a piston assembly including a connecting rod having pistons on both ends, the cylinder being split into two substantially identical portions by a seal through which the connecting rod passes. Vents in the cylinder wall are provided near the seal to permit gas to escape the cylinder until the piston covers the vent whereupon the remaining gas in the cylinder functions as a gas spring and cushions the piston against impact on the seal. The connecting rod has a central portion of relatively small diameter providing free play of the connecting rod through the seal and end portions of relatively large diameter providing a limited tolerance between the connecting rod and the seal. Finally, the seal comprises a seal ring assembly consisting of a dampener plate, a free floating seal at the center of the dampener plate and a seal retainer plate in one face of the dampener plate.

  1. 75 FR 36034 - Advance Notice of Proposed Rulemaking on Lead Emissions From Piston-Engine Aircraft Using Leaded...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-24

    ...: EPA is announcing a 60-day extension of the public comment period for the Advance Notice of Proposed... Register on April 28, 2010. The public comment period was to end on June 28, 2010 (60 days after its publication in the Federal Register). This document extends the comment period an additional 60 days...

  2. MPT Prediction of Aircraft-Engine Fan Noise

    NASA Technical Reports Server (NTRS)

    Connell, Stuart D.

    2004-01-01

    A collection of computer programs has been developed that implements a procedure for predicting multiple-pure-tone (MPT) noise generated by fan blades of an aircraft engine (e.g., a turbofan engine). MPT noise arises when the fan is operating with supersonic relative tip Mach No. Under this flow condition, there is a strong upstream running shock. The strength and position of this shock are very sensitive to blade geometry variations. For a fan where all the blades are identical, the primary tone observed upstream of the fan will be the blade passing frequency. If there are small variations in geometry between blades, then tones below the blade passing frequency arise MPTs. Stagger angle differences as small as 0.1 can give rise to significant MPT. It is also noted that MPT noise is more pronounced when the fan is operating in an unstarted mode. Computational results using a three-dimensional flow solver to compute the complete annulus flow with non-uniform fans indicate that MPT noise can be estimated in a relatively simple way. Hence, once the effect of a typical geometry variation of one blade in an otherwise uniform blade row is known, the effect of all the blades being different can be quickly computed via superposition. Two computer programs that were developed as part of this work are used in conjunction with a user s computational fluid dynamics (CFD) code to predict MPT spectra for a fan with a specified set of geometric variations: (1) The first program ROTBLD reads the users CFD solution files for a single blade passage via an API (Application Program Interface). There are options to replicate and perturb the geometry with typical variations stagger, camber, thickness, and pitch. The multi-passage CFD solution files are then written in the user s file format using the API. (2) The second program SUPERPOSE requires two input files: the first is the circumferential upstream pressure distribution extracted from the CFD solution on the multi-passage mesh

  3. Modal analysis of an aircraft engine fan noise

    NASA Astrophysics Data System (ADS)

    Gorodkova, Natalia; Chursin, Valeriy; Bersenev, Yuliy; Burdakov, Ruslan; Siner, Aleksandr; Viskova, Tatiana

    2016-10-01

    The fan is one of the main noise sources of an aircraft engine. To reduce fan noise and provide liner optimization in the inlet it is necessary to research modal structure of the fan noise. The present paper contains results of acoustic tests on installation for mode generation that consists of 34-channel generator and the inlet updated for mounting of 100 microphones, the experiments were provided in new anechoic chamber of Perm National Research Polytechnic University, the engine with the same inlet was also tested in the open test bench conditions, and results of the fan noise modal structure are presented. For modal structure educting, all 100 channels were synchronously registered in a given frequency range. The measured data were analyzed with PULSE analyzer using fast Fourier transform with a frequency resolution 8..16 Hz. Single modes with numbers from 0 to 35 at frequencies 500; 630; 800; 1000; 1250; 1600 Hz and different combinations of modes at frequencies 1000, 1600, 2000, 2500 Hz were set during tests. Modes with small enough numbers are generated well on the laboratory installation, high-number modes generate additional modes caused by a complicated interference pattern of sound field in the inlet. Open test bench results showed that there are also a lot of harmonic components at frequencies lower than fan BPF. Under 0.65 of cut off there is only one distinct mode, other modes with close and less numbers appear from 0.7 of cut off and above. At power regimes 0.76 and 0.94 of cut off the highest mode also changes from positive to negative mode number area. Numbers of the highest modes change smoothly enough with the growth of power regime. At power regimes with Mach>1 (0.7 of cut off and above) on circumference of blade wheel there is a well-defined noise of shock waves at rotor frequency harmonics that appears at the range between the first rotor frequency and fan blade passing frequency (BPF). It is planned to continue researching of sound field

  4. Study of LH2-fueled topping cycle engine for aircraft propulsion

    NASA Technical Reports Server (NTRS)

    Turney, G. E.; Fishbach, L. H.

    1983-01-01

    An analytical investigation was made of a topping cycle aircraft engine system which uses a cryogenic fuel. This system consists of a main turboshaft engine which is mechanically coupled (by cross-shafting) to a topping loop which augments the shaft power output of the system. The thermodynamic performance of the topping cycle engine was analyzed and compared with that of a reference (conventional-type) turboshaft engine. For the cycle operating conditions selected, the performance of the topping cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping cycle engine is comparable to that of the reference turboshaft engine.

  5. 14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... maintenance, preventive maintenance, rebuilding, or alteration. 43.7 Section 43.7 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE..., propellers, appliances, or component parts for return to service after maintenance, preventive...

  6. 14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... maintenance, preventive maintenance, rebuilding, or alteration. 43.7 Section 43.7 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE..., propellers, appliances, or component parts for return to service after maintenance, preventive...

  7. 14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... maintenance, preventive maintenance, rebuilding, or alteration. 43.7 Section 43.7 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE..., propellers, appliances, or component parts for return to service after maintenance, preventive...

  8. 14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... maintenance, preventive maintenance, rebuilding, or alteration. 43.7 Section 43.7 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE..., propellers, appliances, or component parts for return to service after maintenance, preventive...

  9. An engine trade study for a supersonic STOVL fighter-attack aircraft, volume 1

    NASA Technical Reports Server (NTRS)

    Beard, B. B.; Foley, W. H.

    1982-01-01

    The best main engine for an advanced STOVL aircraft flight demonstrator was studied. The STOVL aircraft uses ejectors powered by engine bypass flow together with vectored core exhaust to achieve vertical thrust capability. Bypass flow and core flow are exhausted through separate nozzles during wingborne flight. Six near term turbofan engines were examined for suitability for this aircraft concept. Fan pressure ratio, thrust split between bypass and core flow, and total thrust level were used to compare engines. One of the six candidate engines was selected for the flight demonstrator configuration. Propulsion related to this aircraft concept was studied. A preliminary candidate for the aircraft reaction control system for hover attitude control was selected. A mathematical model of transfer of bypass thrust from ejectors to aft directed nozzle during the transition to wingborne flight was developed. An equation to predict ejector secondary air flow rate and ram drag is derived. Additional topics discussed include: nozzle area control, ejector to engine inlet reingestion, bypass/core thrust split variation, and gyroscopic behavior during hover.

  10. A simulator investigation of engine failure compensation for powered-lift STOL aircraft

    NASA Technical Reports Server (NTRS)

    Nieuwenhuijse, A. W.; Franklin, J. A.

    1974-01-01

    A piloted simulator investigation of various engine failure compensation concepts for powered-lift STOL aircraft was carried out at the Ames Research Center. The purpose of this investigation was to determine the influence of engine failure compensation on recovery from an engine failure during the landing approach and on the precision of the STOL landing. The various concepts include: (1) cockpit warning lights to cue the pilot of an engine failure, (2) programmed thrust and roll trim compensation, (3) thrust command and (4) flight-path stabilization. The aircraft simulated was a 150 passenger four-engine, externally blown flap civil STOL transport having a 90 psf wing loading and a .56 thrust to weight ratio. Results of the simulation indicate that the combination of thrust command and flight-path stabilization offered the best engine-out landing performance in turbulence and did so over the entire range of altitudes for which engine failures occurred.

  11. Evaluation of Methods for the Determination of Black Carbon Emissions from an Aircraft Gas Turbine Engine

    EPA Science Inventory

    The emissions from aircraft gas turbine engines consist of nanometer size black carbon (BC) particles plus gas-phase sulfur and organic compounds which undergo gas-to-particle conversion downstream of the engine as the plume cools and dilutes. In this study, four BC measurement ...

  12. Minimum time acceleration of aircraft turbofan engines by using an algorithm based on nonlinear programming

    NASA Technical Reports Server (NTRS)

    Teren, F.

    1977-01-01

    Minimum time accelerations of aircraft turbofan engines are presented. The calculation of these accelerations was made by using a piecewise linear engine model, and an algorithm based on nonlinear programming. Use of this model and algorithm allows such trajectories to be readily calculated on a digital computer with a minimal expenditure of computer time.

  13. The Effect of Modified Control Limits on the Performance of a Generic Commercial Aircraft Engine

    NASA Technical Reports Server (NTRS)

    Csank, Jeffrey T.; May, Ryan D.; Gou, Ten-Huei; Litt, Jonathan S.

    2012-01-01

    This paper studies the effect of modifying the control limits of an aircraft engine to obtain additional performance. In an emergency situation, the ability to operate an engine above its normal operating limits and thereby gain additional performance may aid in the recovery of a distressed aircraft. However, the modification of an engine s limits is complex due to the risk of an engine failure. This paper focuses on the tradeoff between enhanced performance and risk of either incurring a mechanical engine failure or compromising engine operability. The ultimate goal is to increase the engine performance, without a large increase in risk of an engine failure, in order to increase the probability of recovering the distressed aircraft. The control limit modifications proposed are to extend the rotor speeds, temperatures, and pressures to allow more thrust to be produced by the engine, or to increase the rotor accelerations and allow the engine to follow a fast transient. These modifications do result in increased performance; however this study indicates that these modifications also lead to an increased risk of engine failure.

  14. Commercial aircraft engine emissions characterization of in-use aircraft at Hartsfield-Jackson Atlanta International Airport.

    PubMed

    Herndon, Scott C; Jayne, John T; Lobo, Prem; Onasch, Timothy B; Fleming, Gregg; Hagen, Donald E; Whitefield, Philip D; Miake-Lye, Richard C

    2008-03-15

    The emissions from in-use commercial aircraft engines have been analyzed for selected gas-phase species and particulate characteristics using continuous extractive sampling 1-2 min downwind from operational taxi- and runways at Hartsfield-Jackson Atlanta International Airport. Using the aircraft tail numbers, 376 plumes were associated with specific engine models. In general, for takeoff plumes, the measured NOx emission index is lower (approximately 18%) than that predicted by engine certification data corrected for ambient conditions. These results are an in-service observation of the practice of "reduced thrust takeoff". The CO emission index observed in ground idle plumes was greater (up to 100%) than predicted by engine certification data for the 7% thrust condition. Significant differences are observed in the emissions of black carbon and particle number among different engine models/technologies. The presence of a mode at approximately 65 nm (mobility diameter) associated with takeoff plumes and a smaller mode at approximately 25 nm associated with idle plumes has been observed. An anticorrelation between particle mass loading and particle number concentration is observed.

  15. A Feasibility Study of Life-Extending Controls for Aircraft Turbine Engines Using a Generic Air Force Model (Preprint)

    DTIC Science & Technology

    2006-12-01

    engine model is a detailed, physics-based engine model of a two-spool, non-augmented, low bypass ratio engine developed using MATLAB/ Simulink ® [9]. The...AFRL-PR-WP-TP-2007-218 A FEASIBILITY STUDY OF LIFE- EXTENDING CONTROLS FOR AIRCRAFT TURBINE ENGINES USING A GENERIC AIR FORCE MODEL (PREPRINT...SUBTITLE A FEASIBILITY STUDY OF LIFE-EXTENDING CONTROLS FOR AIRCRAFT TURBINE ENGINES USING A GENERIC AIR FORCE MODEL (PREPRINT) 5c. PROGRAM ELEMENT

  16. Stirling engine with pressurized crankcase

    DOEpatents

    Corey, John A.

    1988-01-01

    A two piston Stirling engine wherein the pistons are coupled to a common crankshaft via bearing means, the pistons include pad means to minimize friction between the pistons and the cylinders during reciprocation of the pistons, means for pressurizing the engine crankcase, and means for cooling the crankshaft and the bearing means eliminating the need for oil in the crankcase.

  17. Design study: A 186 kW lightweight diesel aircraft engine

    NASA Technical Reports Server (NTRS)

    Brouwers, A. P.

    1980-01-01

    The design of an aircraft engine capable of developing 186 kW shaft power at a 7620 m altitude is described. The 186 kW design takes into account expected new developments in aircraft designs resulting in a reassessment of the power requirements at the cruise mode operation. Based on the results of this analysis a three phase technology development program is projected resulting in production dates of 1985, 1992, and 2000.

  18. Advanced General Aviation Turbine Engine (GATE) study

    NASA Technical Reports Server (NTRS)

    Smith, R.; Benstein, E. H.

    1979-01-01

    The small engine technology requirements suitable for general aviation service in the 1987 to 1988 time frame were defined. The market analysis showed potential United States engines sales of 31,500 per year providing that the turbine engine sales price approaches current reciprocating engine prices. An optimum engine design was prepared for four categories of fixed wing aircraft and for rotary wing applications. A common core approach was derived from the optimum engines that maximizes engine commonality over the power spectrum with a projected price competitive with reciprocating piston engines. The advanced technology features reduced engine cost, approximately 50 percent compared with current technology.

  19. A Study of Bird Ingestions Into Large High Bypass Ratio Turbine Aircraft Engines.

    DTIC Science & Technology

    1984-09-01

    4. SUMMARY 37 5. CONCLUSIONS 39 6. UEFERENCES 41 APPENDICES A - Comparison of HBPR Engine Aircraft B - HIVE Engines C - Statistical Procesures D...allow a reliable assessment of the bird ingestion phenomenon. Sufficient data to conduct a statistical analysis based upon the numbers, weights, and...species of birds. Sufficient data to conduct a statistical analysis of the engine damage resulting from a bird ingestion - considering the bird number

  20. The impact of emissions standards on the design of aircraft gas turbine engine combustors

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1976-01-01

    Effective emission control techniques have been identified and a wide spectrum of potential applications for these techniques to existing and advanced engines are being considered. Results from advanced combustor concept evaluations and from fundamental experiments are presented and discussed and comparisons are made with existing EPA emission standards and recommended levels for high altitude cruise. The impact that the advanced low emission concepts may impose on future aircraft engine combustor designs and related engine components is discussed.

  1. 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

  2. Engine/airframe compatibility studies for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Technology assessment studies were conducted to provide an updated technology base from which an advanced supersonic cruise aircraft can be produced with a high probability of success. An assessment of the gains available through the application of advanced technologies in aerodynamics, propulsion, acoustics, structures, materials, and active controls is developed. The potential market and range requirements as well as economic factors including payload, speed, airline operating costs, and airline profitability are analyzed. The conceptual design of the baseline aircraft to be used in assessing the technology requirements is described.

  3. The STOL performance of a two-engine, USB powered-lift aircraft with cross-shafted fans

    NASA Technical Reports Server (NTRS)

    Stevens, V. C.; Wilson, S. B., III; Zola, C. A.

    1985-01-01

    The short takeoff and landing capabilities that characterize the performance of powered-lift aircraft are dependent on engine thrust and are, therefore, severely affected by loss of an engine. This paper shows that the effects of engine loss on the short takeoff and landing performance of powered-lift aircraft can be effectively mitigated by cross-shafting the engine fans in a twin-engine configuration. Engine-out takeoff and landing performances are compared for three powered-lift aircraft configurations: one with four engines, one with two engines, and one with two engines in which the fans are cross-shafted. The results show that the engine-out takeoff and landing performance of the cross-shafted two-engine configuration is significantly better than that of the two-engine configuration without cross-shafting.

  4. A Sensitivity Study of Commercial Aircraft Engine Response for Emergency Situations

    NASA Technical Reports Server (NTRS)

    Csank, Jeffrey T.; May, Ryan D.; Litt, Jonathan S.; Guo, Ten-Huei

    2011-01-01

    This paper contains the details of a sensitivity study in which the variation in a commercial aircraft engine's outputs is observed for perturbations in its operating condition inputs or control parameters. This study seeks to determine the extent to which various controller limits can be modified to improve engine performance, while capturing the increased risk that results from the changes. In an emergency, the engine may be required to produce additional thrust, respond faster, or both, to improve the survivability of the aircraft. The objective of this paper is to propose changes to the engine controller and determine the costs and benefits of the additional capabilities produced by the engine. This study indicates that the aircraft engine is capable of producing additional thrust, but at the cost of an increased risk of an engine failure due to higher turbine temperatures and rotor speeds. The engine can also respond more quickly to transient commands, but this action reduces the remaining stall margin to possibly dangerous levels. To improve transient response in landing scenarios, a control mode known as High Speed Idle is proposed that increases the responsiveness of the engine and conserves stall margin

  5. Computer code for estimating installed performance of aircraft gas turbine engines. Volume 3: Library of maps

    NASA Technical Reports Server (NTRS)

    Kowalski, E. J.

    1979-01-01

    A computerized method which utilizes the engine performance data and estimates the installed performance of aircraft gas turbine engines is presented. This installation includes: engine weight and dimensions, inlet and nozzle internal performance and drag, inlet and nacelle weight, and nacelle drag. The use of two data base files to represent the engine and the inlet/nozzle/aftbody performance characteristics is discussed. The existing library of performance characteristics for inlets and nozzle/aftbodies and an example of the 1000 series of engine data tables is presented.

  6. A Study on Aircraft Engine Control Systems for Integrated Flight and Propulsion Control

    NASA Astrophysics Data System (ADS)

    Yamane, Hideaki; Matsunaga, Yasushi; Kusakawa, Takeshi

    A flyable FADEC system engineering model incorporating Integrated Flight and Propulsion Control (IFPC) concept is developed for a highly maneuverable aircraft and a fighter-class engine. An overview of the FADEC system and functional assignments for its components such as the Engine Control Unit (ECU) and the Integrated Control Unit (ICU) are described. Overall system reliability analysis, convex analysis and multivariable controller design for the engine, fault detection/redundancy management, and response characteristics of a fuel system are addressed. The engine control performance of the FADEC is demonstrated by hardware-in-the-loop simulation for fast acceleration and thrust transient characteristics.

  7. Integration of On-Line and Off-Line Diagnostic Algorithms for Aircraft Engine Health Management

    NASA Technical Reports Server (NTRS)

    Kobayashi, Takahisa; Simon, Donald L.

    2007-01-01

    This paper investigates the integration of on-line and off-line diagnostic algorithms for aircraft gas turbine engines. The on-line diagnostic algorithm is designed for in-flight fault detection. It continuously monitors engine outputs for anomalous signatures induced by faults. The off-line diagnostic algorithm is designed to track engine health degradation over the lifetime of an engine. It estimates engine health degradation periodically over the course of the engine s life. The estimate generated by the off-line algorithm is used to update the on-line algorithm. Through this integration, the on-line algorithm becomes aware of engine health degradation, and its effectiveness to detect faults can be maintained while the engine continues to degrade. The benefit of this integration is investigated in a simulation environment using a nonlinear engine model.

  8. Polymer, metal, and ceramic matrix composites for advanced aircraft engine applications

    SciTech Connect

    Mc Daniels, D.L.; Serafini, T.T.; Di Carlo, J.A.

    1986-06-01

    Advanced aircraft engine research within NASA Lewis focuses on propulsion systems for subsonic, supersonic, and hypersonic aircraft. Each of these flight regimes requires different types of engines, but all require advanced materials to meet their goals of performance, thrust-to-weight ratio, and fuel efficiency. The high strength/weight and stiffness/weight properties of resin, metal, and ceramic matrix composites will play an increasingly key role in meeting these performance requirements. At NASA Lewis, research is ongoing to apply graphite/polyimide composites to engine components and to develop polymer matrices with higher operating temperature capabilities. Metal matrix composites, using magnesium, aluminum, titanium, and superalloy matrices, are being developed for application to static and rotating engine components, as well as for space applications, over a broad temperature range. Ceramic matrix composites are also being examined to increase the toughness and reliability of ceramics for application to high-temperature engine structures and components.

  9. Computerized systems analysis and optimization of aircraft engine performance, weight, and life cycle costs

    NASA Technical Reports Server (NTRS)

    Fishbach, L. H.

    1980-01-01

    The computational techniques are described which are utilized at Lewis Research Center to determine the optimum propulsion systems for future aircraft applications and to identify system tradeoffs and technology requirements. Cycle performance, and engine weight can be calculated along with costs and installation effects as opposed to fuel consumption alone. Almost any conceivable turbine engine cycle can be studied. These computer codes are: NNEP, WATE, LIFCYC, INSTAL, and POD DRG. Examples are given to illustrate how these computer techniques can be applied to analyze and optimize propulsion system fuel consumption, weight and cost for representative types of aircraft and missions.

  10. Jet engine exhaust emissions of high altitude commercial aircraft projected to 1990

    NASA Technical Reports Server (NTRS)

    Grobman, J.; Ingebo, R. D.

    1974-01-01

    Projected minimum levels of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high-altitude cruise conditions are presented. The forecasts are based on:(1) current knowledge of emission characteristics of combustors and augmentors; (2) the status of combustion research in emission reduction technology; and (3) predictable trends in combustion systems and operating conditions as required for projected engine designs that are candidates for advanced subsonic or supersonic commercial aircraft fueled by either JP fuel, liquefied natural gas, or hydrogen. Results are presented for cruise conditions in terms of both an emission index (g constituent/kg fuel) and an emission rate (g constituent/hr).

  11. Sonic IR crack detection of aircraft turbine engine blades with multi-frequency ultrasound excitations

    SciTech Connect

    Zhang, Ding; Han, Xiaoyan; Newaz, Golam

    2014-02-18

    Effectively and accurately detecting cracks or defects in critical engine components, such as turbine engine blades, is very important for aircraft safety. Sonic Infrared (IR) Imaging is such a technology with great potential for these applications. This technology combines ultrasound excitation and IR imaging to identify cracks and flaws in targets. In general, failure of engine components, such as blades, begins with tiny cracks. Since the attenuation of the ultrasound wave propagation in turbine engine blades is small, the efficiency of crack detection in turbine engine blades can be quite high. The authors at Wayne State University have been developing the technology as a reliable tool for the future field use in aircraft engines and engine parts. One part of the development is to use finite element modeling to assist our understanding of effects of different parameters on crack heating while experimentally hard to achieve. The development has been focused with single frequency ultrasound excitation and some results have been presented in a previous conference. We are currently working on multi-frequency excitation models. The study will provide results and insights of the efficiency of different frequency excitation sources to foster the development of the technology for crack detection in aircraft engine components.

  12. Advanced stratified charge rotary aircraft engine design study

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

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

  13. Pistons and Cylinders Made of Carbon-Carbon Composite Materials

    NASA Technical Reports Server (NTRS)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    2000-01-01

    An improved reciprocating internal combustion engine has a plurality of engine pistons, which are fabricated from carbon-carbon composite materials, in operative association with an engine cylinder block, or an engine cylinder tube, or an engine cylinder jug, all of which are also fabricated from carbon-carbon composite materials.

  14. The horsepower of aircraft engines and their maximum frontal area

    NASA Technical Reports Server (NTRS)

    Precoul, Michel

    1936-01-01

    This adaptation of a Russian report reveals the effect of maximum cross section of an engine as well as the interest attaching to a choice not solely based on horsepower. The tabulation gives a comparison between different engines restored at 5,000 meters. Radial versus inverted in-line engines are also compared.

  15. Air Force F-16 Aircraft Engine Aerosol Emissions Under Cruise Altitude Conditions

    NASA Technical Reports Server (NTRS)

    Anderson, Bruce E.; Cofer, W. Randy, III; McDougal, David S.

    1999-01-01

    Selected results from the June 1997 Third Subsonic Assessment Near-Field Interactions Flight (SNIF-III) Experiment are documented. The primary objectives of the SNIF-III experiment were to determine the partitioning and abundance of sulfur species and to examine the formation and growth of aerosol particles in the exhaust of F-16 aircraft as a function of atmospheric and aircraft operating conditions and fuel sulfur concentration. This information is, in turn, being used to address questions regarding the fate of aircraft fuel sulfur impurities and to evaluate the potential of their oxidation products to perturb aerosol concentrations and surface areas in the upper troposphere. SNIF-III included participation of the Vermont and New Jersey Air National Guard F-16's as source aircraft and the Wallops Flight Facility T-39 Sabreliner as the sampling platform. F-16's were chosen as a source aircraft because they are powered by the modern F-100 Series 220 engine which is projected to be representative of future commercial aircraft engine technology. The T-39 instrument suite included sensors for measuring volatile and non-volatile condensation nuclei (CN), aerosol size distributions over the range from 0.1 to 3.0 (micro)m, 3-D winds, temperature, dewpoint, carbon dioxide (CO2), sulfur dioxide (SO2), sulfuric acid (H2SO4), and nitric acid (HNO3).

  16. Roles, uses, and benefits of general aviation aircraft in aerospace engineering education

    NASA Technical Reports Server (NTRS)

    Odonoghue, Dennis P.; Mcknight, Robert C.

    1994-01-01

    Many colleges and universities throughout the United States offer outstanding programs in aerospace engineering. In addition to the fundamentals of aerodynamics, propulsion, flight dynamics, and air vehicle design, many of the best programs have in the past provided students the opportunity to design and fly airborne experiments on board various types of aircraft. Sadly, however, the number of institutions offering such 'airborne laboratories' has dwindled in recent years. As a result, opportunities for students to apply their classroom knowledge, analytical skills, and engineering judgement to the development and management of flight experiments on an actual aircraft are indeed rare. One major reason for the elimination of flight programs by some institutions, particularly the smaller colleges, is the prohibitive cost of operating and maintaining an aircraft as a flying laboratory. The purpose of this paper is to discuss simple, low-cost, relevant flight experiments that can be performed using readily available general aviation aircraft. This paper examines flight experiments that have been successfully conducted on board the NASA Lewis Research Center's T-34B aircraft, as part of the NASA/AIAA/University Flight Experiment Program for Students (NAUFEPS) and discusses how similar experiments could be inexpensively performed on other general aviation aircraft.

  17. Aircraft Design Considerations to Meet One Engine Inoperative (OEI) Safety Requirements

    NASA Technical Reports Server (NTRS)

    Scott, Mark W.

    2012-01-01

    Commercial airlines are obligated to operate such that an aircraft can suffer an engine failure at any point in its mission and terminate the flight without an accident. Only minimal aircraft damage is allowable, such as brake replacement due to very heavy application, or an engine inspection and/or possible removal due to use of an emergency rating. Such performance criteria are often referred to as zero exposure, referring to zero accident exposure to an engine failure. The critical mission segment for meeting one engine inoperative (OEI) criteria is takeoff. For a given weight, wind, and ambient condition, fixed wing aircraft require a balanced field length. This is the longer of the distance to take off if an engine fails at a predetermined critical point in the takeoff profile, or the distance to reject the takeoff and brake to a stop. Rotorcraft have requirements for horizontal takeoff procedures that are equivalent to a balanced field length requirements for fixed wing aircraft. Rotorcraft also perform vertical procedures where no runway or heliport distance is available. These were developed primarily for elevated heliports as found on oil rigs or rooftops. They are also used for ground level operations as might be found at heliports at the end of piers or other confined areas.

  18. Description and Laboratory Tests of a Roots Type Aircraft Engine Supercharger

    NASA Technical Reports Server (NTRS)

    Ware, Marsden

    1926-01-01

    This report describes a roots type aircraft engine supercharger and presents the results of some tests made with it at the Langley Field Laboratories of the National Advisory Committee for Aeronautics. The supercharger used in these tests was constructed largely of aluminum, weighed 88 pounds and was arranged to be operated from the rear of a standard aircraft engine at a speed of 1 1/2 engine crankshaft speed. The rotors of the supercharger were cycloidal in form and were 11 inches long and 9 1/2 inches in diameter. The displacement of the supercharger was 0.51 cubic feet of air per revolution of the rotors. The supercharger was tested in the laboratory, independently and in combination with a Liberty-12 aircraft engine, under simulated altitude pressure conditions in order to obtain information on its operation and performance. From these tests it seems evident that the Roots blower compares favorably with other compressor types used as aircraft engine superchargers and that it has several features that make it particularly attractive for such use.

  19. Stabilizing gas bearing in free piston machines

    NASA Technical Reports Server (NTRS)

    Dhar, Manmohan (Inventor)

    1992-01-01

    In a free piston engine, to reduce dynamic loads on the reciprocating elements caused by a time varying pressure gradient across the gas bearing and close clearance seals provided therein, drain galleries are incorporated at the ends of the gas bearings to isolate the same, and circumferentially spaced grooves are incorporated in the close clearance seal region.

  20. A plume capture technique for the remote characterization of aircraft engine emissions.

    PubMed

    Johnson, G R; Mazaheri, M; Ristovski, Z D; Morawska, L

    2008-07-01

    A technique for capturing and analyzing plumes from unmodified aircraft or other combustion sources under real world conditions is described and applied to the task of characterizing plumes from commercial aircraft during the taxiing phase of the Landing/Take-Off (LTO) cycle. The method utilizes a Plume Capture and Analysis System (PCAS) mounted in a four-wheel drive vehicle which is positioned in the airfield 60 to 180 m downwind of aircraft operations. The approach offers low test turnaround times with the ability to complete careful measurements of particle and gaseous emission factors and sequentially scanned particle size distributions without distortion due to plume concentration fluctuations. These measurements can be performed for individual aircraft movements at five minute intervals. A Plume Capture Device (PCD) collected samples of the naturally diluted plume in a 200 L conductive membrane conforming to a defined shape. Samples from over 60 aircraft movements were collected and analyzed in situ for particulate and gaseous concentrations and for particle size distribution using a Scanning Particle Mobility Sizer (SMPS). Emission factors are derived for particle number, NO(x), and PM2.5 for a widely used commercial aircraft type, Boeing 737 airframes with predominantly CFM56 class engines, during taxiing. The practical advantages of the PCAS include the capacity to perform well targeted and controlled emission factor and size distribution measurements using instrumentation with varying response times within an airport facility, in close proximity to aircraft during their normal operations.

  1. Altitude and airspeed effects on the optimum synchrophase angles for a four-engine propeller aircraft

    NASA Astrophysics Data System (ADS)

    Blunt, David M.

    2014-08-01

    Noise and vibration is a serious problem in all types of aircraft. Any techniques that lower cabin noise and vibration levels by even a few decibels with little or no weight or performance penalties are worth pursuing. Propeller synchrophasing is one such technique that has shown potential in aircraft with two or more propellers; however this technique is not being used to its full potential because the synchrophase angles are typically fixed. This paper provides a detailed examination of how the optimum synchrophase angles in a typical four-engine propeller aircraft vary with different altitudes and airspeeds, and how this information could lead to the design of new adaptive propeller synchrophasing systems and potentially yield improvements to other active noise control measures in propeller aircraft.

  2. USAF Aircraft Engine Emission Goals: A Critical Review.

    DTIC Science & Technology

    1979-09-01

    dif- ficult to obtain. Combustion product gases at the exhaust plane are extremely reactive and at high temperature; consequently, much of the CO and...19. KEY WORDS (Continue on reverse side if necessary and identify by block number) J Pollution Abatement Exhaust Emissions Combustion Aircraft...The USAF must continue basic research in areas of combustion , smoke formation, etc. it - -W: (7) Variability of emissions is an area where more

  3. Preliminary Fatigue Studies on Aluminum Alloy Aircraft Engines

    NASA Technical Reports Server (NTRS)

    1938-01-01

    Preliminary information on the complex subject of the fatigue strength of fabricated structural members for aircraft is presented in the test results obtained on several different types of airship girders subjected to axial tension and compression in a resonance fatigue machine. A description of this machine as well as numerous photographs of the fatigue failures are given. There is also presented an extended bibliography on the subject of fatigue strength.

  4. Emergency Multiengine Aircraft System for Lateral Control Using Differential Thrust Control of Wing Engines

    NASA Technical Reports Server (NTRS)

    Burken, John J. (Inventor); Burcham, Frank W., Jr. (Inventor); Bull, John (Inventor)

    2000-01-01

    Development of an emergency flight control system is disclosed for lateral control using only differential engine thrust modulation of multiengine aircraft is currently underway. The multiengine has at least two engines laterally displaced to the left and right from the axis of the aircraft. In response to a heading angle command psi(sub c) is to be tracked. By continually sensing the heading angle psi of the aircraft and computing a heading error signal psi(sub e) as a function of the difference between the heading angle command psi(sub c) and the sensed heading angle psi, a track control signal is developed with compensation as a function of sensed bank angle phi. Bank angle rate phi, or roll rate p, yaw rate tau, and true velocity produce an aircraft thrust control signal ATC(sub psi(L,R)). The thrust control signal is differentially applied to the left and right engines, with equal amplitude and opposite sign, such that a negative sign is applied to the control signal on the side of the aircraft. A turn is required to reduce the error signal until the heading feedback reduces the error to zero.

  5. Design and test of aircraft engine isolators for reduced interior noise

    NASA Technical Reports Server (NTRS)

    Unruh, J. F.; Scheidt, D. C.

    1982-01-01

    Improved engine vibration isolation was proposed to be the most weight and cost efficient retrofit structure-borne noise control measure for single engine general aviation aircraft. A study was carried out the objectives: (1) to develop an engine isolator design specification for reduced interior noise transmission, (2) select/design candidate isolators to meet a 15 dB noise reduction design goal, and (3) carry out a proof of concept evaluation test. Analytical model of the engine, vibration isolators and engine mount structure were coupled to an empirical model of the fuselage for noise transmission evaluation. The model was used to develop engine isolator dynamic properties design specification for reduced noise transmission. Candidate isolators ere chosen from available product literature and retrofit to a test aircraft. A laboratory based test procedure was then developed to simulate engine induced noise transmission in the aircraft for a proof of concept evaluation test. Three candidate isolator configurations were evaluated for reduced structure-borne noise transmission relative to the original equipment isolators.

  6. The Effect of Faster Engine Response on the Lateral Directional Control of a Damaged Aircraft

    NASA Technical Reports Server (NTRS)

    May, Ryan D.; Lemon, Kimberly A.; Csank, Jeffrey T.; Litt, Jonathan S.; Guo, Ten-Huei

    2012-01-01

    The integration of flight control and propulsion control has been a much discussed topic, especially for emergencies where the engines may be able to help stabilize and safely land a damaged aircraft. Previous research has shown that for the engines to be effective as flight control actuators, the response time to throttle commands must be improved. Other work has developed control modes that accept a higher risk of engine failure in exchange for improved engine response during an emergency. In this effort, a nonlinear engine model (the Commercial Modular Aero-Propulsion System Simulation 40k) has been integrated with a nonlinear airframe model (the Generic Transport Model) in order to evaluate the use of enhanced-response engines as alternative yaw rate control effectors. Tests of disturbance rejection and command tracking were used to determine the impact of the engines on the aircraft's dynamical behavior. Three engine control enhancements that improve the response time of the engine were implemented and tested in the integrated simulation. The enhancements were shown to increase the engine s effectiveness as a yaw rate control effector when used in an automatic feedback loop. The improvement is highly dependent upon flight condition; the airframe behavior is markedly improved at low altitude, low speed conditions, and relatively unchanged at high altitude, high speed.

  7. A method to estimate weight and dimensions of small aircraft propulsion gas turbine engines: User's guide

    NASA Technical Reports Server (NTRS)

    Hale, P. L.

    1982-01-01

    The weight and major envelope dimensions of small aircraft propulsion gas turbine engines are estimated. The computerized method, called WATE-S (Weight Analysis of Turbine Engines-Small) is a derivative of the WATE-2 computer code. WATE-S determines the weight of each major component in the engine including compressors, burners, turbines, heat exchangers, nozzles, propellers, and accessories. A preliminary design approach is used where the stress levels, maximum pressures and temperatures, material properties, geometry, stage loading, hub/tip radius ratio, and mechanical overspeed are used to determine the component weights and dimensions. The accuracy of the method is generally better than + or - 10 percent as verified by analysis of four small aircraft propulsion gas turbine engines.

  8. Impacts of broadened-specification fuels on aircraft turbine engine combustors

    SciTech Connect

    Bahr, D.W.

    1982-11-01

    In the future, aircraft turbine engines may be required to accommodate fuels with lower hydrogen contents, fluidity/volatility characteristics, and thermal stability ratings than those of present-day jet fuels. The key results of several investigations conducted to quantify the impacts of such fuel property changes on the performance, pollutant emission, and durability characteristics of aircraft turbine engine combustors are reviewed. These results were obtained in both component and engine tests of the current production combustors used in the CF6-6, CF6-50, F101/CFM56, and J79/CJ805 engines. Based on these results, it is concluded that the most significant concerns associated with such fuel property changes are decreased combustor life, decreased ground starting/altitude relight capabilities, and increased fuel injector gumming/coking tendencies. The combustor design improvements that appear to be needed to permit the use of jet fuels of significantly lower quality than present day fuels are also reviewed.

  9. Effect of NACA Injection Impeller on Mixture Distribution of Double-Row Radial Aircraft Engine

    NASA Technical Reports Server (NTRS)

    Marble, Frank E; Ritter, William K; Miller, Mahlon A

    1945-01-01

    The NACA injection impeller was developed to improve the mixture distribution of aircraft engines by discharging the fuel from a centrifugal supercharger impeller and thus to promote a thorough mixing of fuel and charge air. Experiments with a double-row radial aircraft engine indicated that for the normal range of engine power the NACA injection impeller provided marked improvement in mixture distribution over the standard spray-bar injection system used in the same engine. The mixture distribution at cruising conditions was excellent; at 1200, 1500, and 1700 brake horsepower, the differences between the fuel-air ratios of the richest and the leanest cylinders were reduced to approximately one-third their former values.

  10. Performance degradation of a typical twin engine commuter type aircraft in measured natural icing conditions

    NASA Technical Reports Server (NTRS)

    Ranaudo, R. J.; Mikkelsen, K. L.; Mcknight, R. C.; Perkins, P. J., Jr.

    1984-01-01

    The performance of an aircraft in various measured icing conditions was investigated. Icing parameters such as liquid water content, temperature, cloud droplet sizes and distributions were measured continuously while in icinig. Flight data wre reduced to provide plots of the aircraft drag polars and lift curves (CL vs. alpha) for the measured 'iced' condition as referenced to the uniced aircraft. These data were also reduced to provide plots of thrust horsepower required vs. single engine power available to show how icing affects engine out capability. It is found that performance degradation is primarily influenced by the amount and shape of the accumulated ice. Glaze icing caused the greatest aerodynamic performance penalties in terms of increased drag and reduction in lift while aerodynamic penalties due to rime icing were significantly lower. Previously announced in STAR as N84-13173

  11. Performance degradation of a typical twin engine commuter type aircraft in measured natural icing conditions

    NASA Technical Reports Server (NTRS)

    Ranaudo, R. J.; Mikkelsen, K. L.; Mcknight, R. C.; Perkins, P. J., Jr.

    1984-01-01

    The performance of an aircraft in various measured icing conditions was investigated. Icing parameters such as liquid water content, temperature, cloud droplet sizes and distributions were measured continuously while in icing. Flight data were reduced to provide plots of the aircraft drag polars and lift curves (CL vs. alpha) for the measured ""iced'' condition as referenced to the uniced aircraft. These data were also reduced to provide plots of thrust horsepower required vs. single engine power available to show how icing affects engine out capability. It is found that performance degradation is primarily influenced by the amount and shape of the accumulated ice. Glaze icing caused the greatest aerodynamic performance penalties in terms of increased drag and reduction in lift while aerodynamic penalties due to rime icing were significantly lower.

  12. Status review of NASA programs for reducing aircraft gas turbine engine emissions

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1976-01-01

    Programs initiated by NASA to develop and demonstrate low emission advanced technology combustors for reducing aircraft gas turbine engine pollution are reviewed. Program goals are consistent with urban emission level requirements as specified by the U. S. Environmental Protection Agency and with upper atmosphere cruise emission levels as recommended by the U. S. Climatic Impact Assessment Program and National Research Council. Preliminary tests of advanced technology combustors indicate that significant reductions in all major pollutant emissions should be attainable in present generation aircraft gas turbine engines without adverse effects on fuel consumption. Preliminary test results from fundamental studies indicate that extremely low emission combustion systems may be possible for future generation jet aircraft. The emission reduction techniques currently being evaluated in these programs are described along with the results and a qualitative assessment of development difficulty.

  13. Study of aerodynamic technology for single-cruise-engine V/STOL fighter/attack aircraft

    NASA Technical Reports Server (NTRS)

    Hess, J. R.; Bear, R. L.

    1982-01-01

    A viable, single engine, supersonic V/STOL fighter/attack aircraft concept was defined. This vectored thrust, canard wing configuration utilizes an advanced technology separated flow engine with fan stream burning. The aerodynamic characteristics of this configuration were estimated and performance evaluated. Significant aerodynamic and aerodynamic propulsion interaction uncertainties requiring additional investigation were identified. A wind tunnel model concept and test program to resolve these uncertainties and validate the aerodynamic prediction methods were defined.

  14. 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.

  15. 77 FR 76842 - Exhaust Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-31

    ... action revises the standards for oxides of nitrogen and test procedures for exhaust emissions based on... Environmental Protection Agency (EPA) proposed new aircraft engine emission standards for oxides of nitrogen (NO... Protection (CAEP) of ICAO uses to differentiate the CAEP work cycles that produce new standards. For...

  16. Weibull-Based Design Methodology for Rotating Aircraft Engine Structures

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    The NASA Energy Efficient Engine (E(sup 3)-Engine) is used as the basis of a Weibull-based life and reliability analysis. Each component's life and thus the engine's life is defined by high-cycle fatigue (HCF) or low-cycle fatigue (LCF). Knowing the cumulative life distribution of each of the components making up the engine as represented by a Weibull slope is a prerequisite to predicting the life and reliability of the entire engine. As the engine Weibull slope increases, the predicted lives decrease. The predicted engine lives L(sub 5) (95 % probability of survival) of approximately 17,000 and 32,000 hr do correlate with current engine maintenance practices without and with refurbishment. respectively. The individual high pressure turbine (HPT) blade lives necessary to obtain a blade system life L(sub 0.1) (99.9 % probability of survival) of 9000 hr for Weibull slopes of 3, 6 and 9, are 47,391 and 20,652 and 15,658 hr, respectively. For a design life of the HPT disks having probable points of failure equal to or greater than 36,000 hr at a probability of survival of 99.9 %, the predicted disk system life L(sub 0.1) can vary from 9,408 to 24,911 hr.

  17. Pollution reduction technology program small jet aircraft engines, phase 3

    NASA Technical Reports Server (NTRS)

    Bruce, T. W.; Davis, F. G.; Kuhn, T. E.; Mongia, H. C.

    1981-01-01

    A series of Model TFE731-2 engine tests were conducted with the Concept 2 variable geometry airblast fuel injector combustion system installed. The engine was tested to: (1) establish the emission levels over the selected points which comprise the Environmental Protection Agency Landing-Takeoff Cycle; (2) determine engine performance with the combustion system; and (3) evaulate the engine acceleration/deceleration characteristics. The hydrocarbon (HC), carbon monoxide (CO), and smoke goals were met. Oxides of nitrogen (NOx) were above the goal for the same configuration that met the other pollutant goals. The engine and combustor performance, as well as acceleration/deceleration characteristics, were acceptable. The Concept 3 staged combustor system was refined from earlier phase development and subjected to further rig refinement testing. The concept met all of the emissions goals.

  18. Aircraft Engine Sensor/Actuator/Component Fault Diagnosis Using a Bank of Kalman Filters

    NASA Technical Reports Server (NTRS)

    Kobayashi, Takahisa; Simon, Donald L. (Technical Monitor)

    2003-01-01

    In this report, a fault detection and isolation (FDI) system which utilizes a bank of Kalman filters is developed for aircraft engine sensor and actuator FDI in conjunction with the detection of component faults. This FDI approach uses multiple Kalman filters, each of which is designed based on a specific hypothesis for detecting a specific sensor or actuator fault. In the event that a fault does occur, all filters except the one using the correct hypothesis will produce large estimation errors, from which a specific fault is isolated. In the meantime, a set of parameters that indicate engine component performance is estimated for the detection of abrupt degradation. The performance of the FDI system is evaluated against a nonlinear engine simulation for various engine faults at cruise operating conditions. In order to mimic the real engine environment, the nonlinear simulation is executed not only at the nominal, or healthy, condition but also at aged conditions. When the FDI system designed at the healthy condition is applied to an aged engine, the effectiveness of the FDI system is impacted by the mismatch in the engine health condition. Depending on its severity, this mismatch can cause the FDI system to generate incorrect diagnostic results, such as false alarms and missed detections. To partially recover the nominal performance, two approaches, which incorporate information regarding the engine s aging condition in the FDI system, will be discussed and evaluated. The results indicate that the proposed FDI system is promising for reliable diagnostics of aircraft engines.

  19. 75 FR 7947 - Airworthiness Directives; Thielert Aircraft Engines GmbH (TAE) Model TAE 125-01 Reciprocating...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... Engines GmbH (TAE) Model TAE 125-01 Reciprocating Engines AGENCY: Federal Aviation Administration (FAA.... The MCAI describes the unsafe condition as: An in-flight engine shutdown incident was reported on an aircraft equipped with a TAE 125-01 engine. This was found to be mainly the result of a blockage of...

  20. Aircraft

    DTIC Science & Technology

    2003-01-01

    national power. But with the recent events such as the war with Iraq, the Severe Acute Respiratory Syndrome (SARS) outbreak, some major carriers... TITLE AND SUBTITLE 2003 Industry Studies: Aircraft 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER

  1. Gaseous Emissions from Aircraft Engines. A Handbook for the Calculation of Emission Indexes and Gaseous Emissions from Aircraft Engines

    DTIC Science & Technology

    1987-09-01

    corresponded to intervals of stable engine operation, as specified by the operators of the engine. Each laboratory reported emission indexes for the read ...period. The test established 50 read periods for gaseous emissions. Tabl, 5-1 gives the emission indexes at idle, high idle, approach, cruise and...emission indexes from a T58-GE-8F engine Test Cell - 12 Location - Naval Air Rework Facility, North Island IDLE Date Time Reading Prior Emission index

  2. Chemical composition and photochemical reactivity of exhaust from aircraft turbine engines

    NASA Astrophysics Data System (ADS)

    Spicer, C. W.; Holdren, M. W.; Riggin, R. M.; Lyon, T. F.

    1994-10-01

    Assessment of the environmental impact of aircraft emissions is required by planners and policy makers. Seveal areas of concern are: 1. exposure of airport workers and urban residents to toxic chemicals emitted when the engines operate at low power (idle and taxi) on the ground; 2. contributions to urban photochemical air pollution of aircraft volatile organic and nitrogen oxides emissions from operations around airports; and 3. emissions of nitrogen oxides and particles during high-altitude operation. The environmental impact of chemicals emitted from jet aircraft turbine engines has not been firmly established due to lack of data regarding emission rates and identities of the compounds emitted. This paper describes an experimental study of two different aircraft turbine engines designed to determine detailed organic emissions, as well as emissions of inorganic gases. Emissions were measured at several engine power settings. Measurements were made of detailed organic composition from C1 through C17, CO, CO2, NO, NOx, and polycyclic aromatic hydrocarbons. Measurements were made using a multi-port sampling pro be positioned directly behind the engine in the exhaust exit plane. The emission measurements have been used to determine the organic distribution by carbon number and the distribution by compound class at each engine power level. The sum of the organic species was compared with an independent measurement of total organic carbon to assess the carbon mass balance. A portion of the exhaust was captured and irradiated in outdoor smog chambers to assess the photochemical reactivity of the emissions with respect to ozone formation. The reactivity of emissions from the two engines was apportioned by chemical compound class.

  3. Variable-cycle engines for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Willis, E.

    1976-01-01

    Progress and the current status of the Variable Cycle Engine (VCE) study are reviewed with emphasis placed on the impact of technology advancements and design specifications. A large variety of VCE concepts are also examined.

  4. Study of unconventional aircraft engines designed for low energy consumption

    NASA Technical Reports Server (NTRS)

    Neitzel, R. E.; Hirschkron, R.; Johnston, R. P.

    1976-01-01

    A study of unconventional engine cycle concepts, which may offer significantly lower energy consumption than conventional subsonic transport turbofans, is described herein. A number of unconventional engine concepts were identified and parametrically studied to determine their relative fuel-saving potential. Based on results from these studies, regenerative, geared, and variable-boost turbofans, and combinations thereof, were selected along with advanced turboprop cycles for further evaluation and refinement. Preliminary aerodynamic and mechanical designs of these unconventional engine configurations were conducted and mission performance was compared to a conventional, direct-drive turofan reference engine. Consideration is given to the unconventional concepts, and their state of readiness for application. Areas of needed technology advancement are identified.

  5. NASA Now: Engineering Design: Tilt Rotors, Aircraft of the Future

    NASA Video Gallery

    Meet Carl Russell, a research aerospace engineer who is working on developing new innovations for air travel. Russell discusses how tilt rotors work, including a demonstration on how rotors use Ber...

  6. Chemical characterization of the fine particle emissions from commercial aircraft engines during the Aircraft Particle Emissions eXperiment (APEX) 1 to 3

    EPA Science Inventory

    This paper addresses the need for detailed chemical information on the fine particulate matter (PM2.5) generated by commercial aviation engines. The exhaust plumes of nine engine models were sampled during the three test campaigns of the Aircraft Particle Emissions eXperiment (AP...

  7. Optimal Tuner Selection for Kalman-Filter-Based Aircraft Engine Performance Estimation

    NASA Technical Reports Server (NTRS)

    Simon, Donald L.; Garg, Sanjay

    2011-01-01

    An emerging approach in the field of aircraft engine controls and system health management is the inclusion of real-time, onboard models for the inflight estimation of engine performance variations. This technology, typically based on Kalman-filter concepts, enables the estimation of unmeasured engine performance parameters that can be directly utilized by controls, prognostics, and health-management applications. A challenge that complicates this practice is the fact that an aircraft engine s performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters such as efficiencies and flow capacities related to each major engine module. Through Kalman-filter-based estimation techniques, the level of engine performance degradation can be estimated, given that there are at least as many sensors as health parameters to be estimated. However, in an aircraft engine, the number of sensors available is typically less than the number of health parameters, presenting an under-determined estimation problem. A common approach to address this shortcoming is to estimate a subset of the health parameters, referred to as model tuning parameters. The problem/objective is to optimally select the model tuning parameters to minimize Kalman-filterbased estimation error. A tuner selection technique has been developed that specifically addresses the under-determined estimation problem, where there are more unknown parameters than available sensor measurements. A systematic approach is applied to produce a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman filter, while minimizing the estimation error in the parameters of interest. Tuning parameter selection is performed using a multi-variable iterative search routine that seeks to minimize the theoretical mean-squared estimation error of the Kalman filter. This approach can significantly reduce the error in onboard aircraft engine parameter estimation

  8. Robust In-Flight Sensor Fault Diagnostics for Aircraft Engine Based on Sliding Mode Observers.

    PubMed

    Chang, Xiaodong; Huang, Jinquan; Lu, Feng

    2017-04-11

    For a sensor fault diagnostic system of aircraft engines, the health performance degradation is an inevitable interference that cannot be neglected. To address this issue, this paper investigates an integrated on-line sensor fault diagnostic scheme for a commercial aircraft engine based on a sliding mode observer (SMO). In this approach, one sliding mode observer is designed for engine health performance tracking, and another for sensor fault reconstruction. Both observers are employed in in-flight applications. The results of the former SMO are analyzed for post-flight updating the baseline model of the latter. This idea is practical and feasible since the updating process does not require the algorithm to be regulated or redesigned, so that ground-based intervention is avoided, and the update process is implemented in an economical and efficient way. With this setup, the robustness of the proposed scheme to the health degradation is much enhanced and the latter SMO is able to fulfill sensor fault reconstruction over the course of the engine life. The proposed sensor fault diagnostic system is applied to a nonlinear simulation of a commercial aircraft engine, and its effectiveness is evaluated in several fault scenarios.

  9. Accurate Measurements of Aircraft Engine Soot Emissions Using a CAPS PMssa Monitor

    NASA Astrophysics Data System (ADS)

    Onasch, Timothy; Thompson, Kevin; Renbaum-Wolff, Lindsay; Smallwood, Greg; Make-Lye, Richard; Freedman, Andrew

    2016-04-01

    We present results of aircraft engine soot emissions measurements during the VARIAnT2 campaign using CAPS PMssa monitors. VARIAnT2, an aircraft engine non-volatile particulate matter (nvPM) emissions field campaign, was focused on understanding the variability in nvPM mass measurements using different measurement techniques and accounting for possible nvPM sampling system losses. The CAPS PMssa monitor accurately measures both the optical extinction and scattering (and thus single scattering albedo and absorption) of an extracted sample using the same sample volume for both measurements with a time resolution of 1 second and sensitivity of better than 1 Mm-1. Absorption is obtained by subtracting the scattering signal from the total extinction. Given that the single scattering albedo of the particulates emitted from the aircraft engine measured at both 630 and 660 nm was on the order of 0.1, any inaccuracy in the scattering measurement has little impact on the accuracy of the ddetermined absorption coefficient. The absorption is converted into nvPM mass using a documented Mass Absorption Coefficient (MAC). Results of soot emission indices (mass soot emitted per mass of fuel consumed) for a turbojet engine as a function of engine power will be presented and compared to results obtained using an EC/OC monitor.

  10. Reducing Conservatism in Aircraft Engine Response Using Conditionally Active Min-Max Limit Regulators

    NASA Technical Reports Server (NTRS)

    May, Ryan D.; Garg, Sanjay

    2012-01-01

    Current aircraft engine control logic uses a Min-Max control selection structure to prevent the engine from exceeding any safety or operational limits during transients due to throttle commands. This structure is inherently conservative and produces transient responses that are slower than necessary. In order to utilize the existing safety margins more effectively, a modification to this architecture is proposed, referred to as a Conditionally Active (CA) limit regulator. This concept uses the existing Min-Max architecture with the modification that limit regulators are active only when the operating point is close to a particular limit. This paper explores the use of CA limit regulators using a publicly available commercial aircraft engine simulation. The improvement in thrust response while maintaining all necessary safety limits is demonstrated in a number of cases.

  11. An Adaptive Instability Suppression Controls Method for Aircraft Gas Turbine Engine Combustors

    NASA Technical Reports Server (NTRS)

    Kopasakis, George; DeLaat, John C.; Chang, Clarence T.

    2008-01-01

    An adaptive controls method for instability suppression in gas turbine engine combustors has been developed and successfully tested with a realistic aircraft engine combustor rig. This testing was part of a program that demonstrated, for the first time, successful active combustor instability control in an aircraft gas turbine engine-like environment. The controls method is called Adaptive Sliding Phasor Averaged Control. Testing of the control method has been conducted in an experimental rig with different configurations designed to simulate combustors with instabilities of about 530 and 315 Hz. Results demonstrate the effectiveness of this method in suppressing combustor instabilities. In addition, a dramatic improvement in suppression of the instability was achieved by focusing control on the second harmonic of the instability. This is believed to be due to a phenomena discovered and reported earlier, the so called Intra-Harmonic Coupling. These results may have implications for future research in combustor instability control.

  12. Integration of Engine, Plume, and CFD Analyses in Conceptual Design of Low-Boom Supersonic Aircraft

    NASA Technical Reports Server (NTRS)

    Li, Wu; Campbell, Richard; Geiselhart, Karl; Shields, Elwood; Nayani, Sudheer; Shenoy, Rajiv

    2009-01-01

    This paper documents an integration of engine, plume, and computational fluid dynamics (CFD) analyses in the conceptual design of low-boom supersonic aircraft, using a variable fidelity approach. In particular, the Numerical Propulsion Simulation System (NPSS) is used for propulsion system cycle analysis and nacelle outer mold line definition, and a low-fidelity plume model is developed for plume shape prediction based on NPSS engine data and nacelle geometry. This model provides a capability for the conceptual design of low-boom supersonic aircraft that accounts for plume effects. Then a newly developed process for automated CFD analysis is presented for CFD-based plume and boom analyses of the conceptual geometry. Five test cases are used to demonstrate the integrated engine, plume, and CFD analysis process based on a variable fidelity approach, as well as the feasibility of the automated CFD plume and boom analysis capability.

  13. Forecast of jet engine exhaust emissions for future high altitude commercial aircraft

    NASA Technical Reports Server (NTRS)

    Grobman, J.; Ingebo, R. D.

    1974-01-01

    Projected minimum levels of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are presented. The forecasts are based on: (1) current knowledge of emission characteristics of combustors and augmentors; (2) the current status of combustion research in emission reduction technology; (3) predictable trends in combustion systems and operating conditions as required for projected engine designs that are candidates for advanced subsonic or supersonic commercial aircraft. Results are presented for cruise conditions in terms of an emission index, g pollutant/kg fuel. Two sets of engine exhaust emission predictions are presented: the first, based on an independent NASA study and the second, based on the consensus of an ad hoc committee composed of industry, university, and government representatives. The consensus forecasts are in general agreement with the NASA forecasts.

  14. Aircraft Wing for Over-The-Wing Mounting of Engine Nacelle

    NASA Technical Reports Server (NTRS)

    Hahn, Andrew S. (Inventor); Kinney, David J. (Inventor)

    2011-01-01

    An aircraft wing has an inboard section and an outboard section. The inboard section is attached (i) on one side thereof to the aircraft's fuselage, and (ii) on an opposing side thereof to an inboard side of a turbofan engine nacelle in an over-the-wing mounting position. The outboard section's leading edge has a sweep of at least 20 degrees. The inboard section's leading edge has a sweep between -15 and +15 degrees, and extends from the fuselage to an attachment position on the nacelle that is forward of an index position defined as an imaginary intersection between the sweep of the outboard section's leading edge and the inboard side of the nacelle. In an alternate embodiment, the turbofan engine nacelle is replaced with an open rotor engine nacelle.

  15. Propeller swirl effect on single-engine general-aviation aircraft stall-spin tendencies

    NASA Technical Reports Server (NTRS)

    Katz, Joseph; Feistel, Terry W.

    1987-01-01

    An investigation is conducted of the effect of a single engine, untapered low wing general aviation aircraft propeller's swirl on the craft's stall pattern. The asymmetrical character of the propeller's swirl can trigger an early stall of one of the wings, aggravating the spin-entry condition. It is shown that the combination of this propeller-induced effect with adverse sideslip can result in large and abrupt changes in the rolling moment, in such conditions as uncoordinated low speed turning maneuvers where the pilot yaws the aircraft with wings level, rather than rolling it.

  16. Impact of future fuel properties on aircraft engines and fuel systems

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  17. Dry piston coal feeder

    DOEpatents

    Hathaway, Thomas J.; Bell, Jr., Harold S.

    1979-01-01

    This invention provides a solids feeder for feeding dry coal to a pressurized gasifier at elevated temperatures substantially without losing gas from the gasifier by providing a lock having a double-acting piston that feeds the coals into the gasifier, traps the gas from escaping, and expels the trapped gas back into the gasifier.

  18. Hot piston ring/cylinder liner materials: Selection and evaluation

    NASA Technical Reports Server (NTRS)

    Sliney, Harold E.

    1988-01-01

    In current designs of the automotive (kinematic) Stirling engine, the piston rings are made of a reinforced polymer and are located below the pistons because they cannot withstand the high temperatures in the upper cylinder area. Theoretically, efficiency could be improved if hot piston rings were located near the top of the pistons. Described is a program to select piston ring and cylinder coating materials to test this theory. Candidate materials were screened, then subjected to a pin or disk friction and wear test machine. Tests were performed in hydrogen at specimen temperatures up to 760 C to simulate environmental conditions in the region of the hot piston ring reversal. Based on the results of these tests, a cobalt based alloy, Stellite 6B, was chosen for the piston rings and PS200, which consists of a metal-bonded chromium carbide matrix with dispersed solid lubricants, was chosen as the cylinder coating. Tests of a modified engine and a baseline engine showed that the hot ring reduced specific fuel consumption by up to 7 percent for some operating conditions and averaged about 3 percent for all conditions evaluated. Related applications of high-temperature coatings for shaft seals and as back-up lubricants are also described.

  19. Self diagnostic accelerometer ground testing on a C-17 aircraft engine

    NASA Astrophysics Data System (ADS)

    Tokars, Roger P.; Lekki, John D.

    The self diagnostic accelerometer (SDA) developed by the NASA Glenn Research Center was tested for the first time in an aircraft engine environment as part of the Vehicle Integrated Propulsion Research (VIPR) program. The VIPR program includes testing multiple critical flight sensor technologies. One such sensor, the accelerometer, measures vibrations to detect faults in the engine. In order to rely upon the accelerometer, the health of the accelerometer must be ensured. Sensor system malfunction is a significant contributor to propulsion in flight shutdowns (IFSD) which can lead to aircraft accidents when the issue is compounded with an inappropriate crew response. The development of the SDA is important for both reducing the IFSD rate, and hence reducing the rate at which this component failure type can put an aircraft in jeopardy, and also as a critical enabling technology for future automated malfunction diagnostic systems. The SDA is a sensor system designed to actively determine the accelerometer structural health and attachment condition, in addition to making vibration measurements. The SDA uses a signal conditioning unit that sends an electrical chirp to the accelerometer and recognizes changes in the response due to changes in the accelerometer health and attachment condition. In an effort toward demonstrating the SDA's flight worthiness and robustness, multiple SDAs were mounted and tested on a C-17 aircraft engine. The engine test conditions varied from engine off, to idle, to maximum power. The two SDA attachment conditions used were fully tight and loose. The newly developed SDA health algorithm described herein uses cross correlation pattern recognition to discriminate a healthy from a faulty SDA. The VIPR test results demonstrate for the first time the robustness of the SDA in an engine environment characterized by high vibration levels.

  20. Self Diagnostic Accelerometer Ground Testing on a C-17 Aircraft Engine

    NASA Technical Reports Server (NTRS)

    Tokars, Roger P.; Lekki, John D.

    2013-01-01

    The self diagnostic accelerometer (SDA) developed by the NASA Glenn Research Center was tested for the first time in an aircraft engine environment as part of the Vehicle Integrated Propulsion Research (VIPR) program. The VIPR program includes testing multiple critical flight sensor technologies. One such sensor, the accelerometer, measures vibrations to detect faults in the engine. In order to rely upon the accelerometer, the health of the accelerometer must be ensured. Sensor system malfunction is a significant contributor to propulsion in flight shutdowns (IFSD) which can lead to aircraft accidents when the issue is compounded with an inappropriate crew response. The development of the SDA is important for both reducing the IFSD rate, and hence reducing the rate at which this component failure type can put an aircraft in jeopardy, and also as a critical enabling technology for future automated malfunction diagnostic systems. The SDA is a sensor system designed to actively determine the accelerometer structural health and attachment condition, in addition to making vibration measurements. The SDA uses a signal conditioning unit that sends an electrical chirp to the accelerometer and recognizes changes in the response due to changes in the accelerometer health and attachment condition. In an effort toward demonstrating the SDAs flight worthiness and robustness, multiple SDAs were mounted and tested on a C-17 aircraft engine. The engine test conditions varied from engine off, to idle, to maximum power. The two SDA attachment conditions used were fully tight and loose. The newly developed SDA health algorithm described herein uses cross correlation pattern recognition to discriminate a healthy from a faulty SDA. The VIPR test results demonstrate for the first time the robustness of the SDA in an engine environment characterized by high vibration levels.