Science.gov

Sample records for advanced turbofan engines

  1. Advanced component technologies for energy-efficient turbofan engines

    NASA Technical Reports Server (NTRS)

    Saunders, N. T.

    1980-01-01

    A cooperative government-industry effort, the Energy Efficient Engine Project, to develop the advanced technology base for future commercial development of a new generation of more fuel conservative turbofan engines for airline use is described. Engine configurations that are dependent upon technology advances in each major engine component are defined and current design and development of the advanced components are included.

  2. Energy Efficient Engine program advanced turbofan nacelle definition study

    NASA Technical Reports Server (NTRS)

    Howe, David C.; Wynosky, T. A.

    1985-01-01

    Advanced, low drag, nacelle configurations were defined for some of the more promising propulsion systems identified in the earlier Benefit/Cost Study, to assess the benefits associated with these advanced technology nacelles and formulate programs for developing these nacelles and low volume thrust reversers/spoilers to a state of technology readiness in the early 1990's. The study results established the design feasibility of advanced technology, slim line nacelles applicable to advanced technology, high bypass ratio turbofan engines. Design feasibility was also established for two low volume thrust reverse/spoiler concepts that meet or exceed the required effectiveness for these engines. These nacelle and thrust reverse/spoiler designs were shown to be applicable in engines with takeoff thrust sizes ranging from 24,000 to 60,000 pounds. The reduced weight, drag, and cost of the advanced technology nacelle installations relative to current technology nacelles offer a mission fuel burn savings ranging from 3.0 to 4.5 percent and direct operating cost plus interest improvements from 1.6 to 2.2 percent.

  3. Advanced component technologies for energy-efficient turbofan engines

    NASA Technical Reports Server (NTRS)

    Saunders, N. T.

    1980-01-01

    The paper reviews NASA's Energy Efficient Engine Project which was initiated to provide the advanced technology base for a new generation of fuel-conservative engines for introduction into airline service by the late 1980s. Efforts in this project are directed at advancing engine component and systems technologies to a point of demonstrating technology-readiness by 1984. Early results indicate high promise in achieving most of the goals established in the project.

  4. Advanced detection, isolation, and accommodation of sensor failures in turbofan engines: Real-time microcomputer implementation

    NASA Technical Reports Server (NTRS)

    Delaat, John C.; Merrill, Walter C.

    1990-01-01

    The objective of the Advanced Detection, Isolation, and Accommodation Program is to improve the overall demonstrated reliability of digital electronic control systems for turbine engines. For this purpose, an algorithm was developed which detects, isolates, and accommodates sensor failures by using analytical redundancy. The performance of this algorithm was evaluated on a real time engine simulation and was demonstrated on a full scale F100 turbofan engine. The real time implementation of the algorithm is described. The implementation used state-of-the-art microprocessor hardware and software, including parallel processing and high order language programming.

  5. Advanced modeling of active control of fan noise for ultra high bypass turbofan engines

    NASA Astrophysics Data System (ADS)

    Hutcheson, Florence Vanel

    1999-11-01

    An advanced model of active control of fan noise for ultra high bypass turbofan engines has been developed. This model is based on a boundary integral equation method and simulates the propagation, radiation and control of the noise generated by an engine fan surrounded by a duct of finite length and cylindrical shape, placed in a uniform flow. Control sources, modeled by point monopoles placed along the wall of the engine inlet or outlet duct, inject anti-noise into the duct to destructively interfere with the sound field generated by the fan. The duct inner wall can be lined or rigid. Unlike current methods, reflection from the duct openings is taken into account, as well as the presence of the evanescent modes. Forward, as well as backward (i.e., from the rear of the engine), external radiation is computed. The development of analytical expressions for the sound field resulting from both the fan loading noise and the control sources is presented. Two fan models are described. The first model uses spinning line sources with radially distributed strength to model the loading force that the fan blades exert on the medium. The second model uses radial arrays of spinning point dipoles to simulate the generation of fan modes of specific modal amplitudes. It is shown that these fan models can provide a reasonable approximation of actual engine fan noise in the instance when the modal amplitude of the propagating modes or the loading force distribution on the fan blades, is known. Sample cases of active noise control are performed to demonstrate the feasibility of the model. The results from these tests indicate that this model (1)is conducive to more realistic studies of active control of fan noise on ultra high bypass turbofan engines because it accounts for the presence of evanescent modes and for interference between inlet and outlet radiation, which were shown to have some impact on the performance of the active control system; (2)is very useful because it allows

  6. On the leading edge; Combining maturity and advanced technology on the F404 turbofan engine

    SciTech Connect

    Powel, S.F. IV )

    1991-01-01

    In this paper the overall design concept of the F404 afterburning turbofan engine is reviewed together with some of the lessons learned from over 2 million flight hours in service. GE Aircraft Engines' derivative and growth plans for the F404 family are then reviewed including the Building Block component development approach. Examples of advanced technologies under development for introduction into new F404 derivative engine models are presented in the areas of materials, digital and fiber optic controls systems, and vectoring exhaust nozzles. The design concept and details of the F404-GE-402, F412-GE-400, and other derivative engines under full-scale development are described. Studies for future growth variants and the benefits of the F404 derivative approach to development of afterburning engines in the 18,000-24,000 lb (80--107 kN) thrust class and non- afterburning engines in the 12,000--19,000 lb (53--85 kN) class are discussed.

  7. Noise-Reduction Benefits Analyzed for Over-the-Wing-Mounted Advanced Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.

    2000-01-01

    As we look to the future, increasingly stringent civilian aviation noise regulations will require the design and manufacture of extremely quiet commercial aircraft. Also, the large fan diameters of modern engines with increasingly higher bypass ratios pose significant packaging and aircraft installation challenges. One design approach that addresses both of these challenges is to mount the engines above the wing. In addition to allowing the performance trend towards large diameters and high bypass ratio cycles to continue, this approach allows the wing to shield much of the engine noise from people on the ground. The Propulsion Systems Analysis Office at the NASA Glenn Research Center at Lewis Field conducted independent analytical research to estimate the noise reduction potential of mounting advanced turbofan engines above the wing. Certification noise predictions were made for a notional long-haul commercial quadjet transport. A large quad was chosen because, even under current regulations, such aircraft sometimes experience difficulty in complying with certification noise requirements with a substantial margin. Also, because of its long wing chords, a large airplane would receive the greatest advantage of any noise-shielding benefit.

  8. Potential improvements in turbofan engine fuel economy

    NASA Technical Reports Server (NTRS)

    Hines, R. W.; Gaffin, W. O.

    1976-01-01

    The method developed for initial evaluation of possible performance improvements in the NASA Aircraft Energy Efficiency Program, directed toward improving the fuel economy of turbofan engines, is outlined, and results of the evaluation of 100 candidate engine modifications are presented. The study indicates that fuel consumption improvements of as much as 5% may be possible in current JT3D, JT8D, and JT9D turbofan engines. Aerodynamic, thermodynamic, material, and structural advances are expected to yield fuel consumption improvements on the order of 10 to 15% in advanced turbofan engines, with the greatest improvement stemming from significantly higher cycle pressure ratios. Higher turbine temperature and fan bypass ratios are also expected to contribute to fuel conservation.

  9. Advanced laser shearography inspection of turbo-fan engine composite fan cases

    NASA Astrophysics Data System (ADS)

    Lape, Dale; Newman, John W.; Craig, David

    1995-07-01

    Shearography inspection techniques have been developed and implemented for the inspection of aluminum honeycomb turbofan aircraft engine fan cases for the JT15D-5D. Shearography has yielded improved sensitivity to unbonds and throughput over ultrasonic techniques formerly used in the production inspection. This paper discusses vacuum stress shearography, test method verification on the JT15D-5D fan case and shearography data correlation with destructive evaluation of test parts.

  10. Turbofan engine cycle design selection - Year 2000

    SciTech Connect

    Steinmetz, R.B.; Wagner, M.J.

    1986-01-01

    To define the optimum turbofan engine cycle for the year 2000, a parametric study was undertaken to define candidate engine thermodynamic cycles for advanced long range aircraft. Performance comparisons are based on uninstalled cruise specific fuel consumption (SFC). A base cycle design with current state-of-the-art technology was established as a reference. A parametric study was then conducted where component technologies projected for the year 2000 were included in the cycle design process. As bypass ratio increased, the transition from direct drive to geared fans was accounted for. Separate versus mixed flow exhaust systems were also studied. An uninstalled SFC improvement of approximately 18 percent was found for the year 2000 turbofan relative to the baseline engine.

  11. Conceptual study of an advanced supersonic technology transport (AST-107) for transpacific range using low-bypass-ratio turbofan engines

    NASA Technical Reports Server (NTRS)

    Morris, S. J., Jr.; Foss, W. E., Jr.; Neubauer, M. J., Jr.

    1980-01-01

    An advanced supersonic technology configuration concept designated the AST-107, using a low bypass ratio turbofan engine, is described and analyzed. The aircraft had provisions for 273 passengers arranged five abreast. The cruise Mach number was 2.62. The mission range for the AST-107 was 8.48 Mm (4576 n.mi.) and an average lift drag ratio of 9.15 during cruise was achieved. The available lateral control was not sufficient for the required 15.4 m/s (30 kt) crosswind landing condition, and a crosswind landing gear or a significant reduction in dihedral effect would be necessary to meet this requirement. The lowest computed noise levels, including a mechanical suppressor noise reduction of 3 EPNdB at the flyover and sideline monitoring stations, were 110.3 EPNdB (sideline noise), 113.1 EPNdB (centerline noise) and 110.5 EPNdB (approach noise).

  12. Advanced Engine Cycles Analyzed for Turbofans With Variable-Area Fan Nozzles Actuated by a Shape Memory Alloy

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.

    2002-01-01

    Advanced, large commercial turbofan engines using low-fan-pressure-ratio, very high bypass ratio thermodynamic cycles can offer significant fuel savings over engines currently in operation. Several technological challenges must be addressed, however, before these engines can be designed. To name a few, the high-diameter fans associated with these engines pose a significant packaging and aircraft installation challenge, and a large, heavy gearbox is often necessary to address the differences in ideal operating speeds between the fan and the low-pressure turbine. Also, the large nacelles contribute aerodynamic drag penalties and require long, heavy landing gear when mounted on conventional, low wing aircraft. Nevertheless, the reduced fuel consumption rates of these engines are a compelling economic incentive, and fans designed with low pressure ratios and low tip speeds offer attractive noise-reduction benefits. Another complication associated with low-pressure-ratio fans is their need for variable flow-path geometry. As the design fan pressure ratio is reduced below about 1.4, an operational disparity is set up in the fan between high and low flight speeds. In other words, between takeoff and cruise there is too large a swing in several key fan parameters-- such as speed, flow, and pressure--for a fan to accommodate. One solution to this problem is to make use of a variable-area fan nozzle (VAFN). However, conventional, hydraulically actuated variable nozzles have weight, cost, maintenance, and reliability issues that discourage their use with low-fan-pressure-ratio engine cycles. United Technologies Research, in cooperation with NASA, is developing a revolutionary, lightweight, and reliable shape memory alloy actuator system that can change the on-demand nozzle exit area by up to 20 percent. This "smart material" actuation technology, being studied under NASA's Ultra-Efficient Engine Technology (UEET) Program and Revolutionary Concepts in Aeronautics (Rev

  13. The Potential Benefits of Advanced Casing Treatment for Noise Attenuation in Utra-High Bypass Ratio Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Elliott, David

    2007-01-01

    In order to increase stall margin in a high-bypass ratio turbofan engine, an advanced casing treatment was developed that extracted a small amount of flow from the casing behind the fan and injected it back in front of the fan. Several different configurations of this casing treatment were designed by varying the distance of the extraction and injection points, as well as varying the amount of flow. These casing treatments were tested on a 55.9 cm (22 in.) scale model of the Pratt & Whitney Advanced Ducted Propulsor in the NASA Glenn 9 by 15 Low Speed Wind Tunnel. While all of the casing treatment configurations showed the expected increase in stall margin, a few of the designs showed a potential noise benefit for certain engine speeds. This paper will show the casing treatments and the results of the testing as well as propose further research in this area. With better prediction and design techniques, future casing treatment configurations could be developed that may result in an optimized casing treatment that could conceivably reduce the noise further.

  14. Turbofan engine core noise source diagnostics

    NASA Technical Reports Server (NTRS)

    Karchmer, Allen M.

    1987-01-01

    The paper describes a turbofan-engine measurement program utilizing a variety of diagnostic techniques to identify a source of core-generated noise which contributes to the overall external engine noise characteristics. Included in the turbofan engine diagnostics are data examination, time domain correlation, and frequency domain analysis. It is found that the turbulent pressure fluctuations within the combustor are a source for core noise which propagates through the nozzle and radiates to the far-field.

  15. Analysis of an advanced technology subsonic turbofan incorporating revolutionary materials

    NASA Technical Reports Server (NTRS)

    Knip, Gerald, Jr.

    1987-01-01

    Successful implementation of revolutionary composite materials in an advanced turbofan offers the possibility of further improvements in engine performance and thrust-to-weight ratio relative to current metallic materials. The present analysis determines the approximate engine cycle and configuration for an early 21st century subsonic turbofan incorporating all composite materials. The advanced engine is evaluated relative to a current technology baseline engine in terms of its potential fuel savings for an intercontinental quadjet having a design range of 5500 nmi and a payload of 500 passengers. The resultant near optimum, uncooled, two-spool, advanced engine has an overall pressure ratio of 87, a bypass ratio of 18, a geared fan, and a turbine rotor inlet temperature of 3085 R. Improvements result in a 33-percent fuel saving for the specified misssion. Various advanced composite materials are used throughout the engine. For example, advanced polymer composite materials are used for the fan and the low pressure compressor (LPC).

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

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

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

  17. Study of Turbofan Engines Designed for Low Enery Consumption

    NASA Technical Reports Server (NTRS)

    Neitzel, R. E.; Hirschkron, R.; Johnston, R. P.

    1976-01-01

    Subsonic transport turbofan engine design and technology features which have promise of improving aircraft energy consumption are described. Task I addressed the selection and evaluation of features for the CF6 family of engines in current aircraft, and growth models of these aircraft. Task II involved cycle studies and the evaluation of technology features for advanced technology turbofans, consistent with initial service in 1985. Task III pursued the refined analysis of a specific design of an advanced technology turbofan engine selected as the result of Task II studies. In all of the above, the impact upon aircraft economics, as well as energy consumption, was evaluated. Task IV summarized recommendations for technology developments which would be necessary to achieve the improvements in energy consumption identified.

  18. Advanced turbofan blade refurbishment technique

    SciTech Connect

    Roberts, W.B.

    1995-10-01

    The purpose of the work reported here is to investigate whether the lessons learned from the work of Suder et al. can be used to reduce the in-service performance deterioration of a fan on a high bypass ratio turbofan engine. To this end, a back-to-back test was done on the fan of an RB211-22B engine with the cooperation of Delta Airlines. The fan and engine were first overhauled per normal airline practice and cell-tested to establish that the engine performance met flight acceptance standards. This test, which the engine passed, also established a performance baseline for the overhauled engine. At this point the fan blade leading edge had not been filed or scraped and the blade surfaces had not been polished because the leading edge damage and blade surface roughness fell within the acceptable limits specified by the manufacturer for normal overhaul practice. After the cell test, the fan was removed from the engine and sent to Sermatech International where the following additional operations were performed: (1) the blade surfaces were polished to a finish of 20 rms {micro}in; (2) leading edge roughness due to particle impact damage was removed and the leading edge was polished to a finish of 20 rms {micro}in; (3) the leading edge shape was rounded and the leading edge thickness was reduced over the first 5--10% of chord. Test results indicated a 0.7% drop in thrust specific fuel consumption (lb fuel/lb thrust/hr) relative to the baseline engine after the enhanced fan overhaul. Based on the results of Suder et al. (1995) it appears that 70--80% of this performance gain is due to the thin smooth leading edge and the remainder to the highly polished finish of the blade.

  19. Noise Reduction Potential of Large, Over-the-Wing Mounted, Advanced Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.

    2000-01-01

    As we look to the future, increasingly stringent civilian aviation noise regulations will require the design and manufacture of extremely quiet commercial aircraft. Indeed, the noise goal for NASA's Aeronautics Enterprise calls for technologies that will help to provide a 20 EPNdB reduction relative to today's levels by the year 2022. Further, the large fan diameters of modem, increasingly higher bypass ratio engines pose a significant packaging and aircraft installation challenge. One design approach that addresses both of these challenges is to mount the engines above the wing. In addition to allowing the performance trend towards large, ultra high bypass ratio cycles to continue, this over-the-wing design is believed to offer noise shielding benefits to observers on the ground. This paper describes the analytical certification noise predictions of a notional, long haul, commercial quadjet transport with advanced, high bypass engines mounted above the wing.

  20. Advanced Turbofan Duct Liner Concepts

    NASA Technical Reports Server (NTRS)

    Bielak, Gerald W.; Premo, John W.; Hersh, Alan S.

    1999-01-01

    The Advanced Subsonic Technology Noise Reduction Program goal is to reduce aircraft noise by 10 EPNdB by the year 2000 relative, to 1992 technology. The improvement goal for nacelle attenuation is 25% relative to 1992 technology by 1997 and 50% by 2000. The Advanced Turbofan Duct Liner Concepts Task work by Boeing presented in this document was in support of these goals. The basis for the technical approach was a Boeing study conducted in 1993-94 under NASA/FAA contract NAS1-19349, Task 6, investigating broadband acoustic liner concepts. As a result of this work, it was recommended that linear double layer, linear and perforate triple layer, parallel element, and bulk absorber liners be further investigated to improve nacelle attenuations. NASA LaRC also suggested that "adaptive" liner concepts that would allow "in-situ" acoustic impedance control also be considered. As a result, bias flow and high-temperature liner concepts were also added to the investigation. The major conclusion from the above studies is that improvements in nacelle liner average acoustic impedance characteristics alone will not result in 25% increased nacelle noise reduction relative to 1992 technology. Nacelle design advancements currently being developed by Boeing are expected to add 20-40% more acoustic lining to hardwall regions in current inlets, which is predicted to result in and additional 40-80% attenuation improvement. Similar advancements are expected to allow 10-30% more acoustic lining in current fan ducts with 10-30% more attenuation expected. In addition, Boeing is currently developing a scarf inlet concept which is expected to give an additional 40-80% attenuation improvement for equivalent lining areas.

  1. ACOUSTIC LINERS FOR TURBOFAN ENGINES

    NASA Technical Reports Server (NTRS)

    Minner, G. L.

    1994-01-01

    This program was developed to design acoustic liners for turbofan engines. This program combines results from theoretical models of wave alternation in acoustically treated passages with experimental data from full-scale fan noise suppressors. By including experimentally obtained information, the program accounts for real effects such as wall boundary layers, duct terminations, and sound modal structure. The program has its greatest use in generating a number of design specifications to be used for evaluation of trade-offs. The program combines theoretical and empirical data in designing annular acoustic liners. First an estimate of the noise output of the fan is made based on basic fan aerodynamic design variables. Then, using a target noise spectrum after alternation and the estimated fan noise spectrum, a design spectrum is calculated as their difference. Next, the design spectrum is combined with knowledge of acoustic liner performance and the liner design variables to specify the acoustic design. Details of the liner design are calculated by combining the required acoustic impedance with a mathematical model relating acoustic impedance to the physical structure of the liner. Input to the noise prediction part of the program consists of basic fan operating parameters, distance that the target spectrum is to be measured and the target spectrum. The liner design portion of the program requires the required alternation spectrum, desired values of length to height and several option selection parameters. Output from the noise prediction portion is a noise spectrum consisting of discrete tones and broadband noise. This may be used as input to the liner design portion of the program. The liner design portion of the program produces backing depths, open area ratios, and face plate thicknesses. This program is written in FORTRAN V and has been implemented in batch mode on a UNIVAC 1100 series computer with a central memory requirement of 12K (decimal) of 36 bit words.

  2. Noise Reduction Technologies for Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Huff, Dennis L.

    2007-01-01

    Significant progress continues to be made with noise reduction for turbofan engines. NASA has conducted and sponsored research aimed at reducing noise from commercial aircraft. Since it takes many years for technologies to be developed and implemented, it is important to have aggressive technology goals that lead the target entry into service dates. Engine noise is one of the major contributors to the overall sound levels as aircraft operate near airports. Turbofan engines are commonly used on commercial transports due to their advantage for higher performance and lower noise. The noise reduction comes from combinations of changes to the engine cycle parameters and low noise design features. In this paper, an overview of major accomplishments from recent NASA research programs for engine noise will be given.

  3. 78 FR 9003 - Airworthiness Directives; Engine Alliance Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-07

    ... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Engine Alliance Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed...

  4. Airesearch QCGAT program. [quiet clean general aviation turbofan engines

    NASA Technical Reports Server (NTRS)

    Heldenbrand, R. W.; Norgren, W. M.

    1979-01-01

    A model TFE731-1 engine was used as a baseline for the NASA quiet clean general aviation turbofan engine and engine/nacelle program designed to demonstrate the applicability of large turbofan engine technology to small general aviation turbofan engines, and to obtain significant reductions in noise and pollutant emissions while reducing or maintaining fuel consumption levels. All new technology design for rotating parts and all items in the engine and nacelle that contributed to the acoustic and pollution characteristics of the engine system were of flight design, weight, and construction. The major noise, emissions, and performance goals were met. Noise levels estimated for the three FAR Part 36 conditions, are 10 t0 15 ENPdB below FAA requirements; emission values are considerably reduced below that of current technology engines; and the engine performance represents a TSFC improvement of approximately 9 percent over other turbofan engines.

  5. Study of turbofan engines designed for low energy consumption

    NASA Technical Reports Server (NTRS)

    Gray, D. E.

    1976-01-01

    The near-term technology improvements which can reduce the fuel consumed in the JT9D, JT8D, and JT3D turbofans in commercial fleet operation through the 1980's are identified. Projected technology advances are identified and evaluated for new turbofans to be developed after 1985. Programs are recommended for developing the necessary technology.

  6. The E3 combustors: Status and challenges. [energy efficient turbofan engines

    NASA Technical Reports Server (NTRS)

    Sokolowski, D. E.; Rohde, J. E.

    1981-01-01

    The design, fabrication, and initial testing of energy efficient engine combustors, developed for the next generation of turbofan engines for commercial aircraft, are described. The combustor designs utilize an annular configuration with two zone combustion for low emissions, advanced liners for improved durability, and short, curved-wall, dump prediffusers for compactness. Advanced cooling techniques and segmented construction characterize the advanced liners. Linear segments are made from castable, turbine-type materials.

  7. 14 CFR 23.934 - Turbojet and turbofan engine thrust reverser systems tests.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... CATEGORY AIRPLANES Powerplant General § 23.934 Turbojet and turbofan engine thrust reverser systems tests. Thrust reverser systems of turbojet or turbofan engines must meet the requirements of § 33.97 of this... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Turbojet and turbofan engine...

  8. 14 CFR 23.934 - Turbojet and turbofan engine thrust reverser systems tests.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... CATEGORY AIRPLANES Powerplant General § 23.934 Turbojet and turbofan engine thrust reverser systems tests. Thrust reverser systems of turbojet or turbofan engines must meet the requirements of § 33.97 of this... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbojet and turbofan engine...

  9. Method and apparatus for rapid thrust increases in a turbofan engine

    NASA Technical Reports Server (NTRS)

    Cornett, J. E.; Corley, R. C.; Fraley, T. O.; Saunders, A. A., Jr. (Inventor)

    1980-01-01

    Upon a landing approach, the normal compressor stator schedule of a fan speed controlled turbofan engine is temporarily varied to substantially close the stators to thereby increase the fuel flow and compressor speed in order to maintain fan speed and thrust. This running of the compressor at an off-design speed substantially reduces the time required to subsequently advance the engine speed to the takeoff thrust level by advancing the throttle and opening the compressor stators.

  10. 78 FR 47235 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-05

    ... Electric Company (GE) model GEnx-2B67 and GEnx-2B67B turbofan engines. This proposed AD was prompted by the... in Boeing 747-8 flight tests had consumed more cyclic life than they would have in revenue flight cycles. These parts were then installed into engines and introduced into revenue service...

  11. State-of-the-art of turbofan engine noise control

    NASA Technical Reports Server (NTRS)

    Jones, W. L.; Groeneweg, J. F.

    1977-01-01

    The technology of turbofan engine noise reduction is surveyed. Specific topics discussed include: (1) new fans for low noise; (2) fan and core noise suppression; (3) turbomachinery noise sources; and (4) a new program for improving static noise testing of fans and engines.

  12. Design study of a dual-cycle turbofan-ramjet engine for a hypersonic aircraft

    NASA Technical Reports Server (NTRS)

    Zumwalt, G. W.; Suwanprasert, S.

    1983-01-01

    Computer modelling was used with two different designs of an advanced turbofan-ramjet in order to derive performance predictions. The engine would enable an aircraft to take-off, accelerate to Mach 5.0, and climb to 90,000 ft. The two concepts included a turbofan with a ramjet annularly wrapped around it and a side-by-side configuration with the ramjet having a rectangular shape and mounted alongside the turbofan. The studies were performed to model weight, length, fuel efficiency, and the requirements of the thrust/drag ratio to exceed unity over the entire flight path. LH2 would be used for fuel and to regeneratively cool the combustion chamber. Turbofan operation with and without afterburner and with and without the ramjet inlet open were examined, as were variable areas for the burners. A side-by-side configuration displayed the best performance predictions, with a ramjet mass flow being 75 percent that of the turbofan and maximum temperatures being equal.

  13. Simulating the Use of Alternative Fuels in a Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.; Chin, Jeffrey Chevoor; Liu, Yuan

    2013-01-01

    The interest in alternative fuels for aviation has created a need to evaluate their effect on engine performance. The use of dynamic turbofan engine simulations enables the comparative modeling of the performance of these fuels on a realistic test bed in terms of dynamic response and control compared to traditional fuels. The analysis of overall engine performance and response characteristics can lead to a determination of the practicality of using specific alternative fuels in commercial aircraft. This paper describes a procedure to model the use of alternative fuels in a large commercial turbofan engine, and quantifies their effects on engine and vehicle performance. In addition, the modeling effort notionally demonstrates that engine performance may be maintained by modifying engine control system software parameters to account for the alternative fuel.

  14. 77 FR 9868 - Airworthiness Directives; Honeywell International Inc. Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation... turbofan engines. This proposed AD was prompted by a report of a rim/web separation of a first stage low... uncontained disk separation, leading to fuel tank penetration, fire, personal injury, and damage to...

  15. 77 FR 67763 - Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-14

    ... NPRM published in the Federal Register on July 11, 2012 (77 FR 40822). That NPRM proposed to require... Executive Order 12866, (2) Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR... Division Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule....

  16. 78 FR 76045 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-16

    ... (GE) GE90-110B1 and GE90-115B turbofan engines with certain high pressure compressor (HPC) rotor stage... flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the...

  17. 78 FR 38195 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-26

    ...; AD 2013-10-52] RIN 2120-AA64 Airworthiness Directives; General Electric Company Turbofan Engines... are adopting a new airworthiness directive (AD) for all General Electric Company (GE) GE90-110B1 and... information identified in this AD, contact General Electric Company, GE-Aviation, Room 285, 1 Neumann...

  18. 76 FR 64844 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-19

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; General Electric... General Electric Company (GE) CF6-45 and CF6-50 series turbofan engines with certain low-pressure turbine... Friday, except Federal holidays. For service information identified in this AD, contact General...

  19. 77 FR 48110 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-13

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; General Electric... certain General Electric Company (GE) CF6-80C2 series turbofan engines. The existing AD requires... Friday, except Federal holidays. For service information identified in this AD, contact General...

  20. 78 FR 19628 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-02

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; General Electric... directive (AD): General Electric Company: Docket No. FAA-2013-0186; Directorate Identifier 2013-NE-11-AD. (a... AD applies to General Electric Company (GE): (1) GE90-76B, -85B, -90B, and -94B turbofan engines...

  1. 77 FR 51695 - Airworthiness Directives; Honeywell International Inc. Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-27

    ... (1) This AD applies to Honeywell International Inc. TFE731-20R, -20AR, -20BR, -40, -40AR, -40R, -50R.... SUMMARY: We are adopting a new airworthiness directive (AD) for all Honeywell International Inc. TFE731-20R, -20AR, -20BR, -40, -40AR, - 40R, -50R, and -60 turbofan engines. This AD was prompted by a...

  2. HYTESS 2: A Hypothetical Turbofan Engine Simplified Simulation with multivariable control and sensor analytical redundancy

    NASA Technical Reports Server (NTRS)

    Merrill, W. C.

    1986-01-01

    A hypothetical turbofan engine simplified simulation with a multivariable control and sensor failure detection, isolation, and accommodation logic (HYTESS II) is presented. The digital program, written in FORTRAN, is self-contained, efficient, realistic and easily used. Simulated engine dynamics were developed from linearized operating point models. However, essential nonlinear effects are retained. The simulation is representative of the hypothetical, low bypass ratio turbofan engine with an advanced control and failure detection logic. Included is a description of the engine dynamics, the control algorithm, and the sensor failure detection logic. Details of the simulation including block diagrams, variable descriptions, common block definitions, subroutine descriptions, and input requirements are given. Example simulation results are also presented.

  3. Analysis of Turbofan Design Options for an Advanced Single-Aisle Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Guynn, Mark D.; Berton, Jeffrey J.; Fisher, Kenneth L.; Haller, William J.; Tong, Michael T.; Thurman, Douglas R.

    2009-01-01

    The desire for higher engine efficiency has resulted in the evolution of aircraft gas turbine engines from turbojets, to low bypass ratio, first generation turbofans, to today's high bypass ratio turbofans. It is possible that future designs will continue this trend, leading to very-high or ultra-high bypass ratio (UHB) engines. Although increased bypass ratio has clear benefits in terms of propulsion system metrics such as specific fuel consumption, these benefits may not translate into aircraft system level benefits due to integration penalties. In this study, the design trade space for advanced turbofan engines applied to a single-aisle transport (737/A320 class aircraft) is explored. The benefits of increased bypass ratio and associated enabling technologies such as geared fan drive are found to depend on the primary metrics of interest. For example, bypass ratios at which fuel consumption is minimized may not require geared fan technology. However, geared fan drive does enable higher bypass ratio designs which result in lower noise. Regardless of the engine architecture chosen, the results of this study indicate the potential for the advanced aircraft to realize substantial improvements in fuel efficiency, emissions, and noise compared to the current vehicles in this size class.

  4. Study of small turbofan engines applicable to general-aviation aircraft

    NASA Technical Reports Server (NTRS)

    Merrill, G. L.; Burnett, G. A.; Alsworth, C. C.

    1973-01-01

    The applicability of small turbofan engines to general aviation aircraft is discussed. The engine and engine/airplane performance, weight, size, and cost interrelationships are examined. The effects of specific engine noise constraints are evaluated. The factors inhibiting the use of turbofan engines in general aviation aircraft are identified.

  5. An Assessment of Gas Foil Bearing Scalability and the Potential Benefits to Civilian Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Bruckner, Robert J.

    2010-01-01

    Over the past several years the term oil-free turbomachinery has been used to describe a rotor support system for high speed turbomachinery that does not require oil for lubrication, damping, or cooling. The foundation technology for oil-free turbomachinery is the compliant foil bearing. This technology can replace the conventional rolling element bearings found in current engines. Two major benefits are realized with this technology. The primary benefit is the elimination of the oil lubrication system, accessory gearbox, tower shaft, and one turbine frame. These components account for 8 to 13 percent of the turbofan engine weight. The second benefit that compliant foil bearings offer to turbofan engines is the capability to operate at higher rotational speeds and shaft diameters. While traditional rolling element bearings have diminished life, reliability, and load capacity with increasing speeds, the foil bearing has a load capacity proportional to speed. The traditional applications for foil bearings have been in small, lightweight machines. However, recent advancements in the design and manufacturing of foil bearings have increased their potential size. An analysis, grounded in experimentally proven operation, is performed to assess the scalability of the modern foil bearing. This analysis was coupled to the requirements of civilian turbofan engines. The application of the foil bearing to larger, high bypass ratio engines nominally at the 120 kN (approx.25000 lb) thrust class has been examined. The application of this advanced technology to this system was found to reduce mission fuel burn by 3.05 percent.

  6. System Noise Prediction of the DGEN 380 Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.

    2015-01-01

    The DGEN 380 is a small, separate-flow, geared turbofan. Its manufacturer, Price Induction, is promoting it for a small twinjet application in the emerging personal light jet market. Smaller, and producing less thrust than other entries in the industry, Price Induction is seeking to apply the engine to a 4- to 5-place twinjet designed to compete in an area currently dominated by propeller-driven airplanes. NASA is considering purchasing a DGEN 380 turbofan to test new propulsion noise reduction technologies in a relevant engine environment. To explore this possibility, NASA and Price Induction have signed a Space Act Agreement and have agreed to cooperate on engine acoustic testing. Static acoustic measurements of the engine were made by NASA researchers during July, 2014 at the Glenn Research Center. In the event that a DGEN turbofan becomes a NASA noise technology research testbed, it is in the interest of NASA to develop procedures to evaluate engine system noise metrics. This report documents the procedures used to project the DGEN static noise measurements to flight conditions and the prediction of system noise of a notional airplane powered by twin DGEN engines.

  7. Effect of flight loads on turbofan engine performance deterioration

    NASA Technical Reports Server (NTRS)

    Stakolich, E. G.; Jay, A.; Todd, E. S.; Kafka, P. G.; White, J. L.

    1979-01-01

    A significant percentage of high-bypass-ratio turbofan engine performance deterioration is caused by an increase in operating clearance between fan/compressor and turbine blades and their outer air seals. These increased clearances result from rubs induced by a combination of engine power transients and aircraft flight loads. An analytical technique for predicting the effect of quasi-steady state aircraft flight loads on engine performance deterioration has been developed and is presented. Thrust, aerodynamic and inertia loads are considered. Analytical results are shown and compared to actual engine test experience.

  8. Effect of flight loads on turbofan engine performance deterioration

    NASA Technical Reports Server (NTRS)

    Stakolich, E. G.; Jay, A.; Todd, E. S.; Kafka, P. G.; White, J. L.

    1978-01-01

    A significant percentage of high bypass ratio, turbofan engine performance deterioration was caused by an increase in operating clearance between fan/compressor and turbine blades and their outer air seals. These increased clearances resulted from rubs induced by a combination of engine power transients and aircraft flight loads. An analytical technique for predicting the effect of quasi-steady state aircraft flight loads on engine performance deterioration was developed and is presented. Thrust, aerodynamic and inertia loads were considered. Analytical results are shown and compared to actual engine test experience.

  9. 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.

  10. Core noise measurements on a YF-102 turbofan engine

    NASA Technical Reports Server (NTRS)

    Reshotko, M.; Karchmer, A. M.; Penko, P. F.; Mcardle, J. G.

    1977-01-01

    Core noise from a YF-102 high bypass ratio turbofan engine was investigated through the use of simultaneous measurements of internal fluctuating pressures and far field noise. Acoustic waveguide probes, located in the engine at the compressor exit, in the combustor, at the turbine exit, and in the core nozzle, were employed to measure internal fluctuating pressures. Spectra showed that the internal signals were free of tones, except at high frequency where machinery noise was present. Data obtained over a wide range of engine conditions suggest that below 60% of maximum fan speed the low frequency core noise contributes significantly to the far field noise.

  11. The Design and Testing of a Miniature Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Cosentino, Gary B.; Murray, James E.

    2009-01-01

    Off-the-shelf jet propulsion in the 50 - 500 lb thrust class sparse. A true twin-spool turbofan in this range does not exist. Adapting an off-the-shelf turboshaft engine is feasible. However the approx.10 Hp SPT5 can t quite make 50 lbs. of thrust. Packaging and integration is challenging, especially the exhaust. Building on our engine using a 25 Hp turboshaft seems promising if the engine becomes available. Test techniques used, though low cost, adequate for the purpose.

  12. Enhanced Fan Noise Modeling for Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Krejsa, Eugene A.; Stone, James R.

    2014-01-01

    This report describes work by consultants to Diversitech Inc. for the NASA Glenn Research Center (GRC) to revise the fan noise prediction procedure based on fan noise data obtained in the 9- by 15 Foot Low-Speed Wind Tunnel at GRC. The purpose of this task is to begin development of an enhanced, analytical, more physics-based, fan noise prediction method applicable to commercial turbofan propulsion systems. The method is to be suitable for programming into a computational model for eventual incorporation into NASA's current aircraft system noise prediction computer codes. The scope of this task is in alignment with the mission of the Propulsion 21 research effort conducted by the coalition of NASA, state government, industry, and academia to develop aeropropulsion technologies. A model for fan noise prediction was developed based on measured noise levels for the R4 rotor with several outlet guide vane variations and three fan exhaust areas. The model predicts the complete fan noise spectrum, including broadband noise, tones, and for supersonic tip speeds, combination tones. Both spectra and directivity are predicted. Good agreement with data was achieved for all fan geometries. Comparisons with data from a second fan, the ADP fan, also showed good agreement.

  13. Study of small turbofan engines applicable to single-engine light airplanes

    NASA Technical Reports Server (NTRS)

    Merrill, G. L.

    1976-01-01

    The design, efficiency and cost factors are investigated for application of turbofan propulsion engines to single engine, general aviation light airplanes. A companion study of a hypothetical engine family of a thrust range suitable to such aircraft and having a high degree of commonality of design features and parts is presented. Future turbofan powered light airplanes can have a lower fuel consumption, lower weight, reduced airframe maintenance requirements and improved engine overhaul periods as compared to current piston engined powered airplanes. Achievement of compliance with noise and chemical emission regulations is expected without impairing performance, operating cost or safety.

  14. 75 FR 44725 - Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    .... SUPPLEMENTARY INFORMATION: On June 3, 2010 (75 FR 31330), we published a proposed AD, FR Doc. 2010-13314, in the... PW4000 Series Turbofan Engines; Correction AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... PW4000 series turbofan engines. The docket number is incorrect in all three of its locations....

  15. 75 FR 57660 - Airworthiness Directives; Rolls-Royce Corporation (RRC) AE 3007A Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-22

    ... Corporation (RRC) AE 3007A Series Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... series turbofan engines. That AD currently requires performing an eddy current inspection (ECI) or...-08-51, Amendment 39-15905 (74 FR 22091, May 12, 2009), with a proposed AD. The proposed AD applies...

  16. 75 FR 7209 - Airworthiness Directives; Rolls-Royce Corporation (RRC) AE 3007A Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-18

    ... Directives; Rolls-Royce Corporation (RRC) AE 3007A Series Turbofan Engines AGENCY: Federal Aviation...: The FAA proposes to adopt a new airworthiness directive (AD) for RRC AE 3007A series turbofan engines... (ECIs) or surface wave ultrasonic testing (SWUT) inspections on high-pressure turbine (HPT) stage...

  17. 76 FR 68660 - Airworthiness Directives; Pratt & Whitney Division (PW) PW4000 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-07

    ... Directives; Pratt & Whitney Division (PW) PW4000 Series Turbofan Engines AGENCY: Federal Aviation... airworthiness directive (AD) for PW4000 series turbofan engines. This proposed AD would require replacing the fuel metering unit (FMU), part number (P/N) 50U150, at the next shop visit after the effective date...

  18. Core noise measurements from a small, general aviation turbofan engine

    NASA Astrophysics Data System (ADS)

    Reshotko, M.; Karchmer, A.

    1980-11-01

    As part of a program to investigate combustor and other core noises, simultaneous measurements of internal fluctuating pressure and far field noise were made with a JT15D turbofan engine. Acoustic waveguide probes, located in the engine at the combustor, at the turbine exit and in the core nozzle wall, were used to measure internal fluctuating pressures. Low frequency acoustic power determined at the core nozzle exit corresponds in level to the far field acoustic power at engine speeds below 65% of maximum, the approach condition. At engine speeds above 65% of maximum, the jet noise dominates in the far field, greatly exceeding that of the core. From coherence measurements, it is shown that the combustor is the dominant source of the low frequency core noise. The results obtained from the JT15D engine were compared with those obtained previously from a YF102 engine, both engines having reverse flow annular combustors and being in the same size class.

  19. Turbofan gas turbine engine with variable fan outlet guide vanes

    NASA Technical Reports Server (NTRS)

    Wood, Peter John (Inventor); Zenon, Ruby Lasandra (Inventor); LaChapelle, Donald George (Inventor); Mielke, Mark Joseph (Inventor); Grant, Carl (Inventor)

    2010-01-01

    A turbofan gas turbine engine includes a forward fan section with a row of fan rotor blades, a core engine, and a fan bypass duct downstream of the forward fan section and radially outwardly of the core engine. The forward fan section has only a single stage of variable fan guide vanes which are variable fan outlet guide vanes downstream of the forward fan rotor blades. An exemplary embodiment of the engine includes an afterburner downstream of the fan bypass duct between the core engine and an exhaust nozzle. The variable fan outlet guide vanes are operable to pivot from a nominal OGV position at take-off to an open OGV position at a high flight Mach Number which may be in a range of between about 2.5-4+. Struts extend radially across a radially inwardly curved portion of a flowpath of the engine between the forward fan section and the core engine.

  20. Design of turbofan engine controls using output feedback regulator theory

    NASA Technical Reports Server (NTRS)

    Merrill, W. C.

    1977-01-01

    A multivariable control design procedure based on output feedback regulator (OFR) theory is applied to the F100 turbofan engine. Results for the OFR design are compared to a design based on linear quadratic regulator (LQR) theory. The OFR feedback control is designed in the full order state space and thus eliminates any need for model reduction techniques. Using the performance measure and control structure of the LQR design, an equivalent OFR feedback control is obtained. The flexibility of the OFR as a control design procedure is demonstrated, and differing feedback control structures are evaluated.

  1. Digital computer program for generating dynamic turbofan engine models (DIGTEM)

    NASA Technical Reports Server (NTRS)

    Daniele, C. J.; Krosel, S. M.; Szuch, J. R.; Westerkamp, E. J.

    1983-01-01

    This report describes DIGTEM, a digital computer program that simulates two spool, two-stream turbofan engines. The turbofan engine model in DIGTEM contains steady-state performance maps for all of the components and has control volumes where continuity and energy balances are maintained. Rotor dynamics and duct momentum dynamics are also included. Altogether there are 16 state variables and state equations. DIGTEM features a backward-differnce integration scheme for integrating stiff systems. It trims the model equations to match a prescribed design point by calculating correction coefficients that balance out the dynamic equations. It uses the same coefficients at off-design points and iterates to a balanced engine condition. Transients can also be run. They are generated by defining controls as a function of time (open-loop control) in a user-written subroutine (TMRSP). DIGTEM has run on the IBM 370/3033 computer using implicit integration with time steps ranging from 1.0 msec to 1.0 sec. DIGTEM is generalized in the aerothermodynamic treatment of components.

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

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

  3. Kalman Filtering with Inequality Constraints for Turbofan Engine Health Estimation

    NASA Technical Reports Server (NTRS)

    Simon, Dan; Simon, Donald L.

    2003-01-01

    Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints (which may be based on physical considerations) are often neglected because they do not fit easily into the structure of the Kalman filter. This paper develops two analytic methods of incorporating state variable inequality constraints in the Kalman filter. The first method is a general technique of using hard constraints to enforce inequalities on the state variable estimates. The resultant filter is a combination of a standard Kalman filter and a quadratic programming problem. The second method uses soft constraints to estimate state variables that are known to vary slowly with time. (Soft constraints are constraints that are required to be approximately satisfied rather than exactly satisfied.) The incorporation of state variable constraints increases the computational effort of the filter but significantly improves its estimation accuracy. The improvement is proven theoretically and shown via simulation results. The use of the algorithm is demonstrated on a linearized simulation of a turbofan engine to estimate health parameters. The turbofan engine model contains 16 state variables, 12 measurements, and 8 component health parameters. It is shown that the new algorithms provide improved performance in this example over unconstrained Kalman filtering.

  4. Effect of spatial inlet temperature and pressure distortion on turbofan engine stability

    NASA Technical Reports Server (NTRS)

    Mehalic, Charles M.

    1988-01-01

    The effects of circumferential and radial inlet temperature distortion, circumferential pressure distortion, and combined temperature and pressure distortion on the stability of an advanced turbofan engine were investigated experimentally at simulated altitude conditions. With circumferential and radial inlet temperature distortion, a flow instability generated by the fan operating near stall caused the high-pressure compressor to surge at, or near, the same time as the fan. The effect of combined distortion was dependent on the relative location of the high-temperature and low-pressure regions; high-pressure compressor stalls occurred when the regions coincided, and fan stalls occurred with the regions separated.

  5. JT8D-100 turbofan engine, phase 1. [noise reduction

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The JT8D turbofan engine, widely used in short and medium range transport aircraft, contributes substantially to airport community noise. The jet noise is predominant in the JT8D engine and may be reduced in a modified engine, without loss of thrust, by increasing the airflow to reduce jet velocity. A configuration study evaluated the effects of fan airflow, fan pressure ratio, and bypass ratio on noise, thrust, and fuel comsumption. The cycle selected for the modified engine was based upon an increased diameter, single-stage fan and two additional core engine compressor stages, which replace the existing two-stage fan. Modifications were also made to the low pressure turbine to provide the increased torque required by the larger diameter fan. The resultant JT8D-100 engine models have the following characteristics at take-off thrust, compared to the current JT8D engine: Airflow and bypass ratio are increased, and fan pressure ratio and engine speed are reduced. The resultant engine is also longer, larger in diameter, and heavier than the JT8D base model, but these latter changes are compensated by the increased thrust and decreased fuel comsumption of the modified engine, thus providing the capability for maintaining the performance of the current JT8D-powered aircraft.

  6. Modeling Commercial Turbofan Engine Icing Risk With Ice Crystal Ingestion

    NASA Technical Reports Server (NTRS)

    Jorgenson, Philip C. E.; Veres, Joseph P.

    2013-01-01

    The occurrence of ice accretion within commercial high bypass aircraft turbine engines has been reported under certain atmospheric conditions. Engine anomalies have taken place at high altitudes that have been attributed to ice crystal ingestion, partially melting, and ice accretion on the compression system components. The result was degraded engine performance, and one or more of the following: loss of thrust control (roll back), compressor surge or stall, and flameout of the combustor. As ice crystals are ingested into the fan and low pressure compression system, the increase in air temperature causes a portion of the ice crystals to melt. It is hypothesized that this allows the ice-water mixture to cover the metal surfaces of the compressor stationary components which leads to ice accretion through evaporative cooling. Ice accretion causes a blockage which subsequently results in the deterioration in performance of the compressor and engine. The focus of this research is to apply an engine icing computational tool to simulate the flow through a turbofan engine and assess the risk of ice accretion. The tool is comprised of an engine system thermodynamic cycle code, a compressor flow analysis code, and an ice particle melt code that has the capability of determining the rate of sublimation, melting, and evaporation through the compressor flow path, without modeling the actual ice accretion. A commercial turbofan engine which has previously experienced icing events during operation in a high altitude ice crystal environment has been tested in the Propulsion Systems Laboratory (PSL) altitude test facility at NASA Glenn Research Center. The PSL has the capability to produce a continuous ice cloud which are ingested by the engine during operation over a range of altitude conditions. The PSL test results confirmed that there was ice accretion in the engine due to ice crystal ingestion, at the same simulated altitude operating conditions as experienced previously in

  7. Turbofan Engine Simulated in a Graphical Simulation Environment

    NASA Technical Reports Server (NTRS)

    Parker, Khary I.; Guo, Ten-Huei

    2004-01-01

    Recently, there has been an increase in the development of intelligent engine technology with advanced active component control. The computer engine models used in these control studies are component-level models (CLM), models that link individual component models of state space and nonlinear algebraic equations, written in a computer language such as Fortran. The difficulty faced in performing control studies on Fortran-based models is that Fortran is not supported with control design and analysis tools, so there is no means for implementing real-time control. It is desirable to have a simulation environment that is straightforward, has modular graphical components, and allows easy access to health, control, and engine parameters through a graphical user interface. Such a tool should also provide the ability to convert a control design into real-time code, helping to make it an extremely powerful tool in control and diagnostic system development. Simulation time management is shown: Mach number versus time, power level angle versus time, altitude versus time, ambient temperature change versus time, afterburner fuel flow versus time, controller and actuator dynamics, collect initial conditions, CAD output, and component-level model: CLM sensor, CAD input, and model output. The Controls and Dynamics Technologies Branch at the NASA Glenn Research Center has developed and demonstrated a flexible, generic turbofan engine simulation platform that can meet these objectives, known as the Modular Aero-Propulsion System Simulation (MAPSS). MAPSS is a Simulink-based implementation of a Fortran-based, modern high pressure ratio, dual-spool, low-bypass, military-type variable-cycle engine with a digital controller. Simulink (The Mathworks, Natick, MA) is a computer-aided control design and simulation package allows the graphical representation of dynamic systems in a block diagram form. MAPSS is a nonlinear, non-real-time system composed of controller and actuator dynamics

  8. Enhanced Core Noise Modeling for Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Stone, James R.; Krejsa, Eugene A.; Clark, Bruce J.

    2011-01-01

    This report describes work performed by MTC Technologies (MTCT) for NASA Glenn Research Center (GRC) under Contract NAS3-00178, Task Order No. 15. MTCT previously developed a first-generation empirical model that correlates the core/combustion noise of four GE engines, the CF6, CF34, CFM56, and GE90 for General Electric (GE) under Contract No. 200-1X-14W53048, in support of GRC Contract NAS3-01135. MTCT has demonstrated in earlier noise modeling efforts that the improvement of predictive modeling is greatly enhanced by an iterative approach, so in support of NASA's Quiet Aircraft Technology Project, GRC sponsored this effort to improve the model. Since the noise data available for correlation are total engine noise spectra, it is total engine noise that must be predicted. Since the scope of this effort was not sufficient to explore fan and turbine noise, the most meaningful comparisons must be restricted to frequencies below the blade passage frequency. Below the blade passage frequency and at relatively high power settings jet noise is expected to be the dominant source, and comparisons are shown that demonstrate the accuracy of the jet noise model recently developed by MTCT for NASA under Contract NAS3-00178, Task Order No. 10. At lower power settings the core noise became most apparent, and these data corrected for the contribution of jet noise were then used to establish the characteristics of core noise. There is clearly more than one spectral range where core noise is evident, so the spectral approach developed by von Glahn and Krejsa in 1982 wherein four spectral regions overlap, was used in the GE effort. Further analysis indicates that the two higher frequency components, which are often somewhat masked by turbomachinery noise, can be treated as one component, and it is on that basis that the current model is formulated. The frequency scaling relationships are improved and are now based on combustor and core nozzle geometries. In conjunction with the Task

  9. 77 FR 20987 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-09

    ..., Amendment 39-16970 (77 FR 13485, March 7, 2012), currently requires inspecting the front combustion liner...; AD 2012-04-14] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc Turbofan Engines...

  10. Multi-Objective Optimization of a Turbofan for an Advanced, Single-Aisle Transport

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.; Guynn, Mark D.

    2012-01-01

    Considerable interest surrounds the design of the next generation of single-aisle commercial transports in the Boeing 737 and Airbus A320 class. Aircraft designers will depend on advanced, next-generation turbofan engines to power these airplanes. The focus of this study is to apply single- and multi-objective optimization algorithms to the conceptual design of ultrahigh bypass turbofan engines for this class of aircraft, using NASA s Subsonic Fixed Wing Project metrics as multidisciplinary objectives for optimization. The independent design variables investigated include three continuous variables: sea level static thrust, wing reference area, and aerodynamic design point fan pressure ratio, and four discrete variables: overall pressure ratio, fan drive system architecture (i.e., direct- or gear-driven), bypass nozzle architecture (i.e., fixed- or variable geometry), and the high- and low-pressure compressor work split. Ramp weight, fuel burn, noise, and emissions are the parameters treated as dependent objective functions. These optimized solutions provide insight to the ultrahigh bypass engine design process and provide information to NASA program management to help guide its technology development efforts.

  11. Towards an Automated Full-Turbofan Engine Numerical Simulation

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  12. Frequency domain compensation of a DYNGEN turbofan engine model

    NASA Technical Reports Server (NTRS)

    Schafer, R. M.; Gejji, R. R.; Hoppner, P. W.; Longenbaker, W. E.; Sain, M. K.

    1977-01-01

    Following Rosenbrock's ideas regarding the advantages of dominance in linear multivariable control systems, a new graphical technique is used for the design of compensators that achieve dominance. The technique is illustrated with an application to the problem of designing compensators for a linear turbofan-engine model. The resulting design is put into perspective by examining it in the light of two other multivariable frequency-domain methods. One, MacFarlane's method of characteristic loci, is used to realize a final design for stability and low interaction. The other is a direct technique based upon the algebraic expansion of the determinant of the return difference in terms of it's elements. Results from simulations carried out on the NASA DYNGEN software are included.

  13. 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.

  14. Aircraft Turbofan Engine Health Estimation Using Constrained Kalman Filtering

    NASA Technical Reports Server (NTRS)

    Simon, Dan; Simon, Donald L.

    2003-01-01

    Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints (which may be based on physical considerations) are often neglected because they do not fit easily into the structure of the Kalman filter. This paper develops an analytic method of incorporating state variable inequality constraints in the Kalman filter. The resultant filter is a combination of a standard Kalman filter and a quadratic programming problem. The incorporation of state variable constraints increases the computational effort of the filter but significantly improves its estimation accuracy. The improvement is proven theoretically and shown via simulation results obtained from application to a turbofan engine model. This model contains 16 state variables, 12 measurements, and 8 component health parameters. It is shown that the new algorithms provide improved performance in this example over unconstrained Kalman filtering.

  15. Analytical evaluation of the impact of broad specification fuels on high bypass turbofan engine combustors

    NASA Technical Reports Server (NTRS)

    Taylor, J. R.

    1979-01-01

    Six conceptual combustor designs for the CF6-50 high bypass turbofan engine and six conceptual combustor designs for the NASA/GE E3 high bypass turbofan engine were analyzed to provide an assessment of the major problems anticipated in using broad specification fuels in these aircraft engine combustion systems. Each of the conceptual combustor designs, which are representative of both state-of-the-art and advanced state-of-the-art combustion systems, was analyzed to estimate combustor performance, durability, and pollutant emissions when using commercial Jet A aviation fuel and when using experimental referee board specification fuel. Results indicate that lean burning, low emissions double annular combustor concepts can accommodate a wide range of fuel properties without a serious deterioration of performance or durability. However, rich burning, single annular concepts would be less tolerant to a relaxation of fuel properties. As the fuel specifications are relaxed, autoignition delay time becomes much smaller which presents a serious design and development problem for premixing-prevaporizing combustion system concepts.

  16. Active control of fan noise from a turbofan engine

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Burdisso, Ricardo A.; Fuller, Christopher R.; O'Brien, Walter F.

    1994-01-01

    A three-channel active control system is applied to an operational turbofan engine to reduce tonal noise produced by both the fan and the high-pressure compressor. The control approach is the feedforward filtered-x least-mean-square algorithm implemented on a digital signal processing board. Reference transducers mounted on the engine case provide blade passing and harmonics frequency information to the controller. Error information is provided by large area microphones placed in the acoustic far field. To minimize the error signal, the controller actuates loudspeakers mounted on the inlet to produce destructive interference. The sound pressure level of the fundamental tone of the fan was reduced using the three-channel controller by up to 16 dB over a +/- 30-deg angle about the engine axis. A single-channel controller could produce reduction over a +/- 15-deg angle. The experimental results show the control to be robust. Outside of the areas contolled, the levels of the tone actually increased due to the generation of radial modes by the control sources. Simultaneous control of two tones is achieved with parallel controllers. The fundamental and the first harmonic tones of the fan were controlled simultaneously with reductions of 12 and 5 dBA, respectively, measured on the engine axis. Simultaneous control was also demonstrated for the fan fundamental and the high-pressure compressor fundamental tones.

  17. Active control of fan noise from a turbofan engine

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Burdisso, Ricardo A.; Fuller, Christopher R.; O'Brien, Walter F.

    1993-01-01

    A three channel active control system is applied to an operational turbofan engine in order to reduce tonal noise produced by both the fan and high pressure compressor. The control approach is the feedforward filtered-x least-mean-square algorithm implemented on a digital signal processing board. Reference transducers mounted on the engine case provides blade passing and harmonics frequency information to the controller. Error information is provided by large area microphones placed in the acoustic far field. In order to minimize the error signal, the controller actuates loudspeakers mounted on the inlet to produce destructive interference. The sound pressure level of the fundamental tone of the fan was reduced using the three channel controller by up to 16 dB over a 60 deg angle about the engine axis. A single channel controller could produce reduction over a 30 deg angle. The experimental results show the control to be robust. Simultaneous control of two tones is done with parallel controllers. The fundamental and the first harmonic tones of the fan were controlled simultaneously with reductions of 12 dBA and 5 dBA, respectively, measured on the engine axis. Simultaneous control was also demonstrated for the fan fundamental and the high pressure compressor fundamental tones.

  18. 78 FR 35752 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-14

    ...-Royce Deutschland Ltd & Co KG (RRD) BR700-725A1-12 turbofan engines with fuel pump tube part number... loss of fuel supply to the engine, which could result in in-flight engine shutdown of one or more... fuel leaks. This condition, if not corrected, could lead to loss of engine fuel supply,...

  19. Active Control of Inlet Noise on the JT15D Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Smith, Jerome P.; Hutcheson, Florence V.; Burdisso, Ricardo A.; Fuller, Chris R.

    1999-01-01

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

  20. Kalman Filter Constraint Tuning for Turbofan Engine Health Estimation

    NASA Technical Reports Server (NTRS)

    Simon, Dan; Simon, Donald L.

    2005-01-01

    Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints are often neglected because they do not fit easily into the structure of the Kalman filter. Recently published work has shown a new method for incorporating state variable inequality constraints in the Kalman filter, which has been shown to generally improve the filter s estimation accuracy. However, the incorporation of inequality constraints poses some risk to the estimation accuracy as the Kalman filter is theoretically optimal. This paper proposes a way to tune the filter constraints so that the state estimates follow the unconstrained (theoretically optimal) filter when the confidence in the unconstrained filter is high. When confidence in the unconstrained filter is not so high, then we use our heuristic knowledge to constrain the state estimates. The confidence measure is based on the agreement of measurement residuals with their theoretical values. The algorithm is demonstrated on a linearized simulation of a turbofan engine to estimate engine health.

  1. 78 FR 17080 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ... Ltd & Co KG (RRD) BR700-710 series turbofan engines. This AD requires replacement of the affected fuel... the splined coupling on the fuel pump. We are issuing this AD to prevent failure of the engine and... coupling. This condition, if not corrected, could lead to failure of engine fuel supply, likely...

  2. New technique for the direct measurement of core noise from aircraft engines. [YF 102 turbofan engine

    NASA Technical Reports Server (NTRS)

    Krejsa, E. A.

    1981-01-01

    The core noise levels from gas turbine aircraft engines were measured using a technique which requires that fluctuating pressures be measured in the far field and at two locations within the engine core. The cross spectra of these measurements are used to determine the levels of the far-field noise that propagated from the engine vore. The technique makes it possible to measure core noise levels even when other noise sources dominate. The technique was applied to signals measured from an Avco Lycoming YF102 turbofan engine. Core noise levels as a function of frequency and radiation angle were measured and are presented over a range of power settings.

  3. Spectral Separation of the Turbofan Engine Coherent Combustion Noise Component

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey Hilton

    2008-01-01

    The core noise components of a dual spool turbofan engine (Honeywell TECH977) were separated by the use of a coherence function. A source location technique based on adjusting the time delay between the combustor pressure sensor signal and the far-field microphone signal to maximize the coherence and remove as much variation of the phase angle with frequency as possible was used. While adjusting the time delay to maximize the coherence and minimize the cross spectrum phase angle variation with frequency, the discovery was made that for the 130 microphone a 90.027 ms time shift worked best for the frequency band from 0 to 200 Hz while a 86.975 ms time shift worked best for the frequency band from 200 to 400 Hz. Since the 0 to 200 Hz band signal took more time to travel the same distance, it is slower than the 200 to 400 Hz band signal. This suggests the 0 to 200 Hz coherent cross spectral density band is partly due to indirect combustion noise attributed to hot spots interacting with the turbine. The signal in the 200 to 400 Hz frequency band is attributed mostly to direct combustion noise.

  4. Program Predicts Broadband Noise from a Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Morin, Bruce L.

    2004-01-01

    Broadband Fan Noise Prediction System (BFaNS) is a computer program that, as its name indicates, predicts the broadband noise generated by the fan stage of a turbofan engine. This noise is the sum of (1) turbulent-inflow noise, which is caused by turbulence impinging on leading edges of the fan and the fan exit guide vane and (2) self noise, which is caused by turbulence convecting past the corresponding trailing edges. The user provides input data on the fan-blade, vane, and flow-path geometries and on the mean and turbulent components of the flow field. BFaNS then calculates the turbulent-inflow noise by use of D. B. Hanson's theory, which relates sound power to the inflow turbulence characteristics and the cascade geometry. Hanson s program, BBCASCADE, is incorporated into BFaNS, wherein it is applied to the rotor and stator in a stripwise manner. The spectra of upstream and downstream sound powers radiated by each strip are summed to obtain the total upstream and downstream sound-power spectra. The self-noise contributions are calculated by S. A. L. Glegg's theory, which is also applied in a stripwise manner. The current version of BFaNS is limited to fans with subsonic tip speeds.

  5. System Would Detect Foreign-Object Damage in Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Torso, James A.; Litt, Jonathan S.

    2006-01-01

    A proposed data-fusion system, to be implemented mostly in software, would further process the digitized and preprocessed outputs of sensors in a turbofan engine to detect foreign-object damage (FOD) [more precisely, damage caused by impingement of such foreign objects as birds, pieces of ice, and runway debris]. The proposed system could help a flight crew to decide what, if any, response is necessary to complete a flight safely, and could aid mechanics in deciding what post-flight maintenance action might be needed. The sensory information to be utilized by the proposed system would consist of (1) the output of an accelerometer in an engine-vibration-monitoring subsystem and (2) features extracted from a gas path analysis. ["Gas path analysis" (GPA) is a term of art that denotes comprehensive analysis of engine performance derived from readings of fuel-flow meters, shaft-speed sensors, temperature sensors, and the like.] The acceleration signal would first be processed by a wavelet-transform-based algorithm, using a wavelet created for the specific purpose of finding abrupt FOD-induced changes in noisy accelerometer signals. Two additional features extracted would be the amplitude of vibration (determined via a single- frequency Fourier transform calculated at the rotational speed of the engine), and the rate of change in amplitude due to an FOD-induced rotor imbalance. This system would utilize two GPA features: the fan efficiency and the rate of change of fan efficiency with time. The selected GPA and vibrational features would be assessed by two fuzzy-logic inference engines, denoted the "Gas Path Expert" and the "Vibration Expert," respectively (see Figure 1). Each of these inference engines would generate a "possibility" distribution for occurrence of an FOD event: Each inference engine would assign, to its input information, degrees of membership, which would subsequently be transformed into basic probability assignments for the gas path and vibration

  6. Comparison of turbine bypass and mixed flow turbofan engines for a high-speed civil transport

    NASA Technical Reports Server (NTRS)

    Seidel, Jonathan A.; Haller, William J.; Berton, Jeffrey J.

    1991-01-01

    A comparison of the turbine bypass engine and the mixed flow turbofan for a Mach 2.4 cruise application is presented. A parametric assessment is conducted for each cycle. Parameters that are investigated for the turbine bypass engine include design bypass, combustor exit temperature, and overall pressure ratio. Parameters that are investigated for the mixed flow turbofan include fan pressure ratio, mixer design pressure ratio, and combustor exit temperature. The engines are analyzed for a 5000-nautical-mile, all supersonic cruise mission to determine the aircraft takeoff gross weights. The effects of takeoff noise, cruise emissions, the addition of subsonic cruise legs, and constrained supersonic cruise altitudes are also evaluated.

  7. Refined Exploration of Turbofan Design Options for an Advanced Single-Aisle Transport

    NASA Technical Reports Server (NTRS)

    Guynn, Mark D.; Berton, Jeffrey J.; Fisher, Kenneth L.; Haller, William J.; Tong, Michael T.; Thurman, Douglas R.

    2011-01-01

    A comprehensive exploration of the turbofan engine design space for an advanced technology single-aisle transport (737/A320 class aircraft) was conducted previously by the authors and is documented in a prior report. Through the course of that study and in a subsequent evaluation of the approach and results, a number of enhancements to the engine design ground rules and assumptions were identified. A follow-on effort was initiated to investigate the impacts of these changes on the original study results. The fundamental conclusions of the prior study were found to still be valid with the revised engine designs. The most significant impact of the design changes was a reduction in the aircraft weight and block fuel penalties incurred with low fan pressure ratio, ultra-high bypass ratio designs. This enables lower noise levels to be pursued (through lower fan pressure ratio) with minor negative impacts on aircraft weight and fuel efficiency. Regardless of the engine design selected, the results of this study indicate the potential for the advanced aircraft to realize substantial improvements in fuel efficiency, emissions, and noise compared to the current vehicles in this size class.

  8. 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.

  9. 78 FR 48339 - Airworthiness Directives; Rolls-Royce Corporation Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-08

    ... ; Internet: www.rolls- royce.com . You may view this service information at the FAA, Engine & Propeller... material at the FAA, call 781-238-7125. Examining the AD Docket You may examine the AD docket on the...-16429 (75 FR 57660, September 22, 2010), for RRC AE 3007A series turbofan engines with an HPT stage...

  10. Procedure for Separating Noise Sources in Measurements of Turbofan Engine Core Noise

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey Hilton

    2006-01-01

    The study of core noise from turbofan engines has become more important as noise from other sources like the fan and jet have been reduced. A multiple microphone and acoustic source modeling method to separate correlated and uncorrelated sources has been developed. The auto and cross spectrum in the frequency range below 1000 Hz is fitted with a noise propagation model based on a source couplet consisting of a single incoherent source with a single coherent source or a source triplet consisting of a single incoherent source with two coherent point sources. Examples are presented using data from a Pratt & Whitney PW4098 turbofan engine. The method works well.

  11. DYNGEN: A program for calculating steady-state and transient performance of turbojet and turbofan engines

    NASA Technical Reports Server (NTRS)

    Sellers, J. F.; Daniele, C. J.

    1975-01-01

    The DYNGEN, a digital computer program for analyzing the steady state and transient performance of turbojet and turbofan engines, is described. The DYNGEN is based on earlier computer codes (SMOTE, GENENG, and GENENG 2) which are capable of calculating the steady state performance of turbojet and turbofan engines at design and off-design operating conditions. The DYNGEN has the combined capabilities of GENENG and GENENG 2 for calculating steady state performance; to these the further capability for calculating transient performance was added. The DYNGEN can be used to analyze one- and two-spool turbojet engines or two- and three-spool turbofan engines without modification to the basic program. A modified Euler method is used by DYNGEN to solve the differential equations which model the dynamics of the engine. This new method frees the programmer from having to minimize the number of equations which require iterative solution. As a result, some of the approximations normally used in transient engine simulations can be eliminated. This tends to produce better agreement when answers are compared with those from purely steady state simulations. The modified Euler method also permits the user to specify large time steps (about 0.10 sec) to be used in the solution of the differential equations. This saves computer execution time when long transients are run. Examples of the use of the program are included, and program results are compared with those from an existing hybrid-computer simulation of a two-spool turbofan.

  12. 77 FR 76977 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-31

    ... (65 FR 10698, February 29, 2000). (c) Applicability This AD applies to all General Electric Company... proposed airworthiness directive (AD) for certain General Electric Company (GE) CF6-80C2 series turbofan... information identified in this AD, contact General Electric Company, GE Aviation, Room 285, 1 Neumann...

  13. 76 FR 77108 - Airworthiness Directives; International Aero Engines Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-12

    ... engines. This AD was prompted by three reports of high- pressure turbine (HPT) case burn-through events... Executive Park, Burlington, MA 01803. For information on the availability of this material at the FAA, call... published in the Federal Register on November 23, 2010 (75 FR 71373). That NPRM proposed to require...

  14. 78 FR 22180 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-15

    ... complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78...'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will not have...-Trent 977B-84, and RB211-Trent 980-84 turbofan engines that incorporate RR production Modification...

  15. 77 FR 56760 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-14

    ... April 11, 2000 (65 FR 19477-78). Authority for This Rulemaking Title 49 of the United States Code... Order 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR... plc Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule;...

  16. 77 FR 32007 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-31

    ... FR 19477-78). Authority for This Rulemaking Title 49 of the United States Code specifies the FAA's... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3... plc Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule;...

  17. 78 FR 68360 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-14

    ...: Airworthiness Directive 2013-19-17, Amendment 39-17599 (78 FR 61171, October 3, 2013), currently requires...-01-AD; Amendment 39-17599; AD 2013-19-17] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc.... That AD applies to all Rolls-Royce plc (RR) RB211-535E4-B-37 series turbofan engines. The AD number...

  18. 75 FR 12663 - Airworthiness Directives; Honeywell International Inc. TFE731 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-17

    ... intermediate case is removed from the low-pressure compressor case. Installation Prohibition (h) After the... Inc. TFE731 series turbofan engines with certain second stage low-pressure compressor rotor (LPCR... NPRM was published in the Federal Register on April 13, 2009 (74 FR 16807) and proposed to remove...

  19. 75 FR 67253 - Airworthiness Directives; Pratt & Whitney (PW) Models PW4074 and PW4077 Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-02

    ... airworthiness directive (AD) for PW PW4074 and PW4077 turbofan engines with 15th stage high-pressure compressor... Register published on April 11, 2000 (65 FR 19477-78). Examining the AD Docket You may examine the AD... removing the disks from service. As of June 30, 2010, 53 disks with cracks in the front rail of the...

  20. 75 FR 55459 - Airworthiness Directives; Pratt & Whitney (PW) PW4000 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-13

    .... We published the proposed AD in the Federal Register on March 25, 2010 (75 FR 14375). That action... Executive Order 12866; (2) Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR...) PW4000 Series Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final...

  1. 75 FR 14375 - Airworthiness Directives; Pratt & Whitney (PW) PW4000 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-25

    ..., 2000 (65 FR 19477-78). Examining the AD Docket You may examine the AD docket on the Internet at http... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Would not have a significant...) PW4000 Series Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice...

  2. Design, evaluation and test of an electronic, multivariable control for the F100 turbofan engine

    NASA Technical Reports Server (NTRS)

    Skira, C. A.; Dehoff, R. L.; Hall, W. E., Jr.

    1980-01-01

    A digital, multivariable control design procedure for the F100 turbofan engine is described. The controller is based on locally linear synthesis techniques using linear, quadratic regulator design methods. The control structure uses an explicit model reference form with proportional and integral feedback near a nominal trajectory. Modeling issues, design procedures for the control law and the estimation of poorly measured variables are presented.

  3. 75 FR 27489 - Airworthiness Directives; Pratt & Whitney Canada Corp. PW615F-A Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-17

    .... Investigation showed that the Fuel Filter Bypass Valve poppet in the Fuel Oil Heat Exchanger (FOHE) on that.... PW615F-A turbofan engines with fuel/oil heat exchanger (FOHE) part number (P/ N) 35C3778-01 or P/N... Federal holidays. Fax: (202) 493-2251. Contact Pratt & Whitney Canada Corp., 1000...

  4. FJ44 Turbofan Engine Test at NASA Glenn Research Center's Aero-Acoustic Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    Lauer, Joel T.; McAllister, Joseph; Loew, Raymond A.; Sutliff, Daniel L.; Harley, Thomas C.

    2009-01-01

    A Williams International FJ44-3A 3000-lb thrust class turbofan engine was tested in the NASA Glenn Research Center s Aero-Acoustic Propulsion Laboratory. This report presents the test set-up and documents the test conditions. Farfield directivity, in-duct unsteady pressures, duct mode data, and phased-array data were taken and are reported separately.

  5. 77 FR 11017 - Airworthiness Directives; Pratt & Whitney (PW) Models PW4074 and PW4077 Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ... FR 47056, August 4, 2011), and adding the following new AD: Pratt & Whitney: Docket No. FAA-2010-1095... (76 FR 47056, August 4, 2011), for all PW PW4074 and PW4077 turbofan engines with 15th stage HPC disks...-14-07 (76 FR 47056, August 4, 2011), we received a request from an operator that we clarify...

  6. 77 FR 12755 - Airworthiness Directives; Pratt & Whitney (PW) Division Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-02

    ... Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska...) Division Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed.... 39.13 by adding the following new airworthiness directive (AD): Pratt & Whitney Division: Docket...

  7. Evaluation of an Outer Loop Retrofit Architecture for Intelligent Turbofan Engine Thrust Control

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.; Sowers, T. Shane

    2006-01-01

    The thrust control capability of a retrofit architecture for intelligent turbofan engine control and diagnostics is evaluated. The focus of the study is on the portion of the hierarchical architecture that performs thrust estimation and outer loop thrust control. The inner loop controls fan speed so the outer loop automatically adjusts the engine's fan speed command to maintain thrust at the desired level, based on pilot input, even as the engine deteriorates with use. The thrust estimation accuracy is assessed under nominal and deteriorated conditions at multiple operating points, and the closed loop thrust control performance is studied, all in a complex real-time nonlinear turbofan engine simulation test bed. The estimation capability, thrust response, and robustness to uncertainty in the form of engine degradation are evaluated.

  8. Simulating Effects of High Angle of Attack on Turbofan Engine Performance

    NASA Technical Reports Server (NTRS)

    Liu, Yuan; Claus, Russell W.; Litt, Jonathan S.; Guo, Ten-Huei

    2013-01-01

    A method of investigating the effects of high angle of attack (AOA) flight on turbofan engine performance is presented. The methodology involves combining a suite of diverse simulation tools. Three-dimensional, steady-state computational fluid dynamics (CFD) software is used to model the change in performance of a commercial aircraft-type inlet and fan geometry due to various levels of AOA. Parallel compressor theory is then applied to assimilate the CFD data with a zero-dimensional, nonlinear, dynamic turbofan engine model. The combined model shows that high AOA operation degrades fan performance and, thus, negatively impacts compressor stability margins and engine thrust. In addition, the engine response to high AOA conditions is shown to be highly dependent upon the type of control system employed.

  9. Preliminary Study on Acoustic Detection of Faults Experienced by a High-Bypass Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Boyle, Devin K.

    2014-01-01

    The vehicle integrated propulsion research (VIPR) effort conducted by NASA and several partners provided an unparalleled opportunity to test a relatively low TRL concept regarding the use of far field acoustics to identify faults occurring in a high bypass turbofan engine. Though VIPR Phase II ground based aircraft installed engine testing wherein a multitude of research sensors and methods were evaluated, an array of acoustic microphones was used to determine the viability of such an array to detect failures occurring in a commercially representative high bypass turbofan engine. The failures introduced during VIPR testing included commanding the engine's low pressure compressor (LPC) exit and high pressure compressor (HPC) 14th stage bleed values abruptly to their failsafe positions during steady state

  10. A real-time simulator of a turbofan engine

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.; Delaat, John C.; Merrill, Walter C.

    1989-01-01

    A real-time digital simulator of a Pratt and Whitney F100 engine has been developed for real-time code verification and for actuator diagnosis during full-scale engine testing. This self-contained unit can operate in an open-loop stand-alone mode or as part of closed-loop control system. It can also be used for control system design and development. Tests conducted in conjunction with the NASA Advanced Detection, Isolation, and Accommodation program show that the simulator is a valuable tool for real-time code verification and as a real-time actuator simulator for actuator fault diagnosis. Although currently a small perturbation model, advances in microprocessor hardware should allow the simulator to evolve into a real-time, full-envelope, full engine simulation.

  11. Design of an air ejector for boundary-layer bleed of an acoustically treated turbofan engine inlet during ground testing

    NASA Technical Reports Server (NTRS)

    Stakolich, E. G.

    1978-01-01

    An air ejector was designed and built to remove the boundary-layer air from the inlet a turbofan engine during an acoustic ground test program. This report describes; (1) how the ejector was sized; (2) how the ejector performed; and (3) the performance of a scale model ejector built and tested to verify the design. With proper acoustic insulation, the ejector was effective in reducing boundary layer thickness in the inlet of the turbofan engine while obtaining the desired acoustic test conditions.

  12. Study of small civil turbofan engines applicable to military trainer airplanes

    NASA Technical Reports Server (NTRS)

    Heldenbrand, R. W.; Merrill, G. L.; Burnett, G. A.

    1975-01-01

    Small turbofan engine design concepts were applied to military trainer airplanes to establish the potential for commonality between civil and military engines. Several trainer configurations were defined and studied. A ""best'' engine was defined for the trainer mission, and sensitivity analyses were performed to determine the effects on airplane size and efficiency of wing loading, power loading, configuration, aerodynamic quality, and engine quality. It is concluded that a small civil aircraft is applicable to military trainer airplanes. Aircraft designed with these engines are smaller, less costly, and more efficient than existing trainer aircraft.

  13. Acoustic Performance of an Advanced Model Turbofan in Three Aeroacoustic Test Facilities

    NASA Technical Reports Server (NTRS)

    Woodward, Richard P.; Hughes, Christopher E.

    2012-01-01

    A model advanced turbofan was acoustically tested in the NASA Glenn 9- by 15-Foot-Low-Speed Wind Tunnel (LSWT), and in two other aeroacoustic facilities. The Universal Propulsion Simulator (UPS) fan was designed and manufactured by the General Electric Aircraft Engines (GEAE) Company, and featured active core, as well as bypass, flow paths. The reference test configurations were with the metal, M4, rotor with hardwall and treated bypass flow ducts. The UPS fan was tested within an airflow at a Mach number of 0.20 (limited flow data were also acquired at a Mach number of 0.25) which is representative of aircraft takeoff and approach conditions. Comparisons were made between data acquired within the airflow (9x15 LSWT and German-Dutch Wind Tunnel (DNW)) and outside of a free jet (Boeing Low Speed Aero acoustic Facility (LSAF) and DNW). Sideline data were acquired on an 89-in. (nominal 4 fan diameters) sideline using the same microphone assembly and holder in the 9x15 LSWT and DNW facilities. These data showed good agreement for similar UPS operating conditions and configurations. Distortion of fan spectra tonal content through a free jet shear layer was documented, suggesting that in-flow acoustic measurements are required for comprehensive fan noise diagnostics. However, there was good agreement for overall sound power level (PWL) fan noise measurements made both within and outside of the test facility airflow.

  14. Analytical Modeling of Herschel-Quincke Concept Applied to Inlet Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Hallez, Raphael F.; Burdisso, Ricardo A.; Gerhold, Carl H. (Technical Monitor)

    2002-01-01

    This report summarizes the key results obtained by the Vibration and Acoustics Laboratories at Virginia Tech over the period from January 1999 to December 2000 on the project 'Investigation of an Adaptive Herschel-Quincke Tube Concept for the Reduction of Tonal and Broadband Noise from Turbofan Engines', funded by NASA Langley Research Center. The Herschel-Quincke (HQ) tube concept is a developing technique the consists of circumferential arrays of tubes around the duct. The analytical model is developed to provide prediction and design guidelines for application of the HQ concept to turbofan engine inlets. An infinite duct model is developed and used to provide insight into attenuation mechanisms and design strategies. Based on this early model, the NASA-developed TBIEM3D code is modified for the HQ system. This model allows for investigation of the HQ system combined with a passive liner.

  15. An automated procedure for developing hybrid computer simulations of turbofan engines

    NASA Technical Reports Server (NTRS)

    Szuch, J. R.; Krosel, S. M.; Bruton, W. M.

    1981-01-01

    This paper offers a systematic, computer-aided, self-documenting methodology for developing hybrid computer simulations of turbofan engines. The methodology that is presented makes use of a host program that can run on a large digital computer and a machine-dependent target (hybrid) program. The host program performs all of the calculations and data manipulations that are needed to transform user-supplied engine design information to a form suitable for the hybrid computer. The host program also trims the self-contained engine model to match specified design point information. A test case is described and comparisons between hybrid simulation and specified engine performance data are presented.

  16. An automated procedure for developing hybrid computer simulations of turbofan engines

    NASA Technical Reports Server (NTRS)

    Szuch, J. R.; Krosel, S. M.

    1980-01-01

    A systematic, computer-aided, self-documenting methodology for developing hybrid computer simulations of turbofan engines is presented. The methodology makes use of a host program that can run on a large digital computer and a machine-dependent target (hybrid) program. The host program performs all of the calculations and date manipulations needed to transform user-supplied engine design information to a form suitable for the hybrid computer. The host program also trims the self contained engine model to match specified design point information. A test case is described and comparisons between hybrid simulation and specified engine performance data are presented.

  17. Fluctuating pressures on fan blades of a turbofan engine: Static and wind-tunnel investigations

    NASA Astrophysics Data System (ADS)

    Schoenster, J. A.

    1982-03-01

    To investigate the fan noise generated from turbofan engines, miniature pressure transducers were used to measure the fluctuating pressure on the fan blades of a JT15D engine. Tests were conducted with the engine operating on an outdoor test stand and in a wind tunnel. It was found that a potential flow interaction between the fan blades and six, large support struts in the bypass duct is a dominant noise source in the JT15D engine. Effects of varying fan speed and the forward speed on the blade pressure are also presented.

  18. Comparison of parametric duct-burning turbofan and non-afterburning turbojet engines in a Mach 2.7 transport

    NASA Technical Reports Server (NTRS)

    Whitlow, J. B., Jr.

    1975-01-01

    A parametric study was made of duct-burning turbofan and suppressed dry turbojet engines installed in a supersonic transport. A range of fan pressure ratios was considered for the separate-flow-fan engines. The turbofan engines were studied both with and without jet noise suppressors. Single- as well as dual-stream suppression was considered. Attention was concentrated on designs yielding sideline noises of FAR 36 (108 EPNdB) and below. Trades were made between thrust and wing area for a constant takeoff field length. The turbofans produced lower airplane gross weights than the turbojets at FAR 36 and below. The advantage for the turbofans increased as the sideline noise limit was reduced. Jet noise suppression, especially for the duct stream, was very beneficial for the turbofan engines as long as duct burning was permitted during takeoff. The maximum dry unsuppressed takeoff mode, however, yielded better results at extremely low noise levels. Noise levels as low as FAR 36-11 EPNdB were obtained with a turbofan in this takeoff mode, but at a considerable gross weight penalty relative to the best FAR 36 results.

  19. Core noise investigation of the CF6-50 turbofan engine

    NASA Technical Reports Server (NTRS)

    Doyle, V. L.

    1980-01-01

    Acoustic data obtained during the running of the CF6-50 turbofan engine on an outdoor test stand are presented. The test was conducted to acquire simultaneous internal and far-field measurements to determine the influence of internally generated noise on the far-field measurements. The data includes internal and far-field narrowband and one-third octave band pressure spectra.

  20. 77 FR 20508 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-05

    ..., we issued AD 2011-08-07, Amendment 39-16657 (76 FR 24798, May 3, 2011), for all RR RB211-Trent 875-17..., and RB211-Trent 895-17 turbofan engines. On September 9, 2011, we also issued a correction (76 FR... Issued Since we issued AD 2011-08-07 (76 FR 24798, May 3, 2011), RR determined that additional S/Ns of...

  1. Variable cycle engines for advanced supersonic transports

    NASA Technical Reports Server (NTRS)

    Howlett, R. A.; Kozlowski, H.

    1975-01-01

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

  2. Design and evaluation of an integrated Quiet, Clean General Aviation Turbofan (QCGAT) engine and aircraft propulsion system

    NASA Technical Reports Server (NTRS)

    German, J.; Fogel, P.; Wilson, C.

    1980-01-01

    The design was based on the LTS-101 engine family for the core engine. A high bypass fan design (BPR=9.4) was incorporated to provide reduced fuel consumption for the design mission. All acoustic and pollutant emissions goals were achieved. A discussion of the preliminary design of a business jet suitable for the developed propulsion system is included. It is concluded that large engine technology can be successfully applied to small turbofans, and noise or pollutant levels need not be constraints for the design of future small general aviation turbofan engines.

  3. Computer method for design of acoustic liners for turbofan engines

    NASA Technical Reports Server (NTRS)

    Minner, G. L.; Rice, E. J.

    1976-01-01

    A design package is presented for the specification of acoustic liners for turbofans. An estimate of the noise generation was made based on modifications of existing noise correlations, for which the inputs are basic fan aerodynamic design variables. The method does not predict multiple pure tones. A target attenuation spectrum was calculated which was the difference between the estimated generation spectrum and a flat annoyance-weighted goal attenuated spectrum. The target spectrum was combined with a knowledge of acoustic liner performance as a function of the liner design variables to specify the acoustic design. The liner design method at present is limited to annular duct configurations. The detailed structure of the liner was specified by combining the required impedance (which is a result of the previous step) with a mathematical model relating impedance to the detailed structure. The design procedure was developed for a liner constructed of perforated sheet placed over honeycomb backing cavities. A sample calculation was carried through in order to demonstrate the design procedure, and experimental results presented show good agreement with the calculated results of the method.

  4. Preliminary experiments on active control of fan noise from a turbofan engine

    NASA Technical Reports Server (NTRS)

    Thomas, R. H.; Burdisso, R. A.; Fuller, C. R.; O'Brien, W. F.

    1993-01-01

    In the preliminary experiments reported here, active acoustic sources positioned around the circumference of a turbofan engine were used to control the fan noise radiated forward through the inlet. The main objective was to demonstrate the potential of active techniques to alleviate the noise pollution that will be produced by the next generation of larger engines. A reduction of up to 19 dB in the radiation directivity was demonstrated in a zone that encompasses a 30-deg angle, near the error sensor, while spillover effects were observed toward the lateral direction. The simultaneous control of two tones was also demonstrated using two identical controllers in a parallel control configuration.

  5. Development of dynamic simulation of TF34-GE-100 turbofan engine with post-stall capability

    NASA Technical Reports Server (NTRS)

    Krosel, S. M.

    1984-01-01

    This paper describes the development of a hybrid computer simulation of a TF34-GE-100 turbofan engine with post-stall capability. The simulation operates in real-time and will be used to test and evaluate stall recovery control modes for this engine. The simulation calculations are performed by an analog computer with a peripheral multivariable function generation unit used for computing bivariate functions. Tabular listings of simulation variables are obtained by interfacing to a digital computer and using a custom software package for data collection and display.

  6. Development of dynamic simulation of TF34-GE-100 turbofan engine with post-stall capability

    NASA Technical Reports Server (NTRS)

    Krosel, S. M.

    1984-01-01

    This paper describes the development of a hybrid computer simulation of a TF34-GE-100 turbofan engine with post-stall capability. The simulation operates in real-time and will be used to test and evaluate stall recovery control modes for this engine. The simulation calculations are performed by an analog computer with a peripheral multivariable function generation unit used for computing bivariate functions. Tabular listings of a simulation variables are obtained by interfacing to a digital computer and using a custom software package for data collection and display.

  7. Effect of Installation of Mixer/Ejector Nozzles on the Core Flow Exhaust of High-Bypass-Ratio Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Harrington, Douglas E.

    1998-01-01

    The aerospace industry is currently investigating the effect of installing mixer/ejector nozzles on the core flow exhaust of high-bypass-ratio turbofan engines. This effort includes both full-scale engine tests at sea level conditions and subscale tests in static test facilities. Subscale model tests are to be conducted prior to full-scale testing. With this approach, model results can be analyzed and compared with analytical predications. Problem areas can then be identified and design changes made and verified in subscale prior to committing to any final design configurations for engine ground tests. One of the subscale model test programs for the integrated mixer/ejector development was a joint test conducted by the NASA Lewis Research Center and Pratt & Whitney Aircraft. This test was conducted to study various mixer/ejector nozzle configurations installed on the core flow exhaust of advanced, high-bypass-ratio turbofan engines for subsonic, commercial applications. The mixer/ejector concept involves the introduction of largescale, low-loss, streamwise vortices that entrain large amounts of secondary air and rapidly mix it with the primary stream. This results in increased ejector pumping relative to conventional ejectors and in more complete mixing within the ejector shroud. The latter improves thrust performance through the efficient energy exchange between the primary and secondary streams. This experimental program was completed in April 1997 in Lewis' CE-22 static test facility. Variables tested included the nozzle area ratio (A9/A8), which ranged from 1.6 to 3.0. This ratio was varied by increasing or decreasing the nozzle throat area, A8. Primary nozzles tested included both lobed mixers and conical primaries. These configurations were tested with and without an outer shroud, and the shroud position was varied by inserting spacers in it. In addition, data were acquired with and without secondary flow.

  8. Performance (Off-Design) Cycle Analysis for a Turbofan Engine With Interstage Turbine Burner

    NASA Technical Reports Server (NTRS)

    Liew, K. H.; Urip, E.; Yang, S. L.; Mattingly, J. D.; Marek, C. J.

    2005-01-01

    This report presents the performance of a steady-state, dual-spool, separate-exhaust turbofan engine, with an interstage turbine burner (ITB) serving as a secondary combustor. The ITB, which is located in the transition duct between the high- and the low-pressure turbines, is a relatively new concept for increasing specific thrust and lowering pollutant emissions in modern jet-engine propulsion. A detailed off-design performance analysis of ITB engines is written in Microsoft(Registered Trademark) Excel (Redmond, Washington) macrocode with Visual Basic Application to calculate engine performances over the entire operating envelope. Several design-point engine cases are pre-selected using a parametric cycle-analysis code developed previously in Microsoft(Registered Trademark) Excel, for off-design analysis. The off-design code calculates engine performances (i.e. thrust and thrust-specific-fuel-consumption) at various flight conditions and throttle settings.

  9. 78 FR 47534 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-06

    ... information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125. Examining the AD Docket You..., Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New...

  10. 75 FR 15326 - Airworthiness Directives; Rolls-Royce plc RB211-Trent 500, 700, and 800 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-29

    ... aviation product, and results from the risk of engine fuel-to-oil heat exchanger (FOHE) blockage. The MCAI..., 556A2-61, 556B2-61, and 560A2-61 turbofan engines with fuel-to-oil heat exchangers (FOHEs) part number... regulations as of January 4, 2010 (74 FR 6222, November 27, 2009). ADDRESSES: The Docket Operations office...

  11. Broadband Fan Noise Prediction System for Turbofan Engines. Volume 3; Validation and Test Cases

    NASA Technical Reports Server (NTRS)

    Morin, Bruce L.

    2010-01-01

    Pratt & Whitney has developed a Broadband Fan Noise Prediction System (BFaNS) for turbofan engines. This system computes the noise generated by turbulence impinging on the leading edges of the fan and fan exit guide vane, and noise generated by boundary-layer turbulence passing over the fan trailing edge. BFaNS has been validated on three fan rigs that were tested during the NASA Advanced Subsonic Technology Program (AST). The predicted noise spectra agreed well with measured data. The predicted effects of fan speed, vane count, and vane sweep also agreed well with measurements. The noise prediction system consists of two computer programs: Setup_BFaNS and BFaNS. Setup_BFaNS converts user-specified geometry and flow-field information into a BFaNS input file. From this input file, BFaNS computes the inlet and aft broadband sound power spectra generated by the fan and FEGV. The output file from BFaNS contains the inlet, aft and total sound power spectra from each noise source. This report is the third volume of a three-volume set documenting the Broadband Fan Noise Prediction System: Volume 1: Setup_BFaNS User s Manual and Developer s Guide; Volume 2: BFaNS User s Manual and Developer s Guide; and Volume 3: Validation and Test Cases. The present volume begins with an overview of the Broadband Fan Noise Prediction System, followed by validation studies that were done on three fan rigs. It concludes with recommended improvements and additional studies for BFaNS.

  12. Stimulation of a turbofan engine for evaluation of multivariable optimal control concepts. [(computerized simulation)

    NASA Technical Reports Server (NTRS)

    Seldner, K.

    1976-01-01

    The development of control systems for jet engines requires a real-time computer simulation. The simulation provides an effective tool for evaluating control concepts and problem areas prior to actual engine testing. The development and use of a real-time simulation of the Pratt and Whitney F100-PW100 turbofan engine is described. The simulation was used in a multi-variable optimal controls research program using linear quadratic regulator theory. The simulation is used to generate linear engine models at selected operating points and evaluate the control algorithm. To reduce the complexity of the design, it is desirable to reduce the order of the linear model. A technique to reduce the order of the model; is discussed. Selected results between high and low order models are compared. The LQR control algorithms can be programmed on digital computer. This computer will control the engine simulation over the desired flight envelope.

  13. Real-time simulation of the TF30-P-3 turbofan engine using a hybrid computer

    NASA Technical Reports Server (NTRS)

    Szuch, J. R.; Bruton, W. M.

    1974-01-01

    A real-time, hybrid-computer simulation of the TF30-P-3 turbofan engine was developed. The simulation was primarily analog in nature but used the digital portion of the hybrid computer to perform bivariate function generation associated with the performance of the engine's rotating components. FORTRAN listings and analog patching diagrams are provided. The hybrid simulation was controlled by a digital computer programmed to simulate the engine's standard hydromechanical control. Both steady-state and dynamic data obtained from the digitally controlled engine simulation are presented. Hybrid simulation data are compared with data obtained from a digital simulation provided by the engine manufacturer. The comparisons indicate that the real-time hybrid simulation adequately matches the baseline digital simulation.

  14. 78 FR 16620 - Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-18

    ... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation...; fax: 860-565-4503. You may view this service information at the FAA, Engine & Propeller Directorate... after receipt. FOR FURTHER INFORMATION CONTACT: Ian Dargin, Aerospace Engineer, Engine &...

  15. 77 FR 54791 - Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ...-565-7700; fax: 860-565-1605. You may view this service information at the FAA, Engine & Propeller... material at the FAA, call 781-238-7125. Examining the AD Docket You may examine the AD docket on the... FURTHER INFORMATION CONTACT: James Gray, Aerospace Engineer, Engine & Propeller Directorate, FAA, 12...

  16. 77 FR 30926 - Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-24

    ...-1605. You may review copies of the referenced service information at the FAA, Engine & Propeller... material at the FAA, call 781-238-7125. Examining the AD Docket You may examine the AD docket on the... after receipt. FOR FURTHER INFORMATION CONTACT: James Gray, Aerospace Engineer, Engine &...

  17. 77 FR 16139 - Airworthiness Directives; Pratt & Whitney (PW) Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-20

    ... referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125. Examining..., Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive...

  18. 77 FR 16921 - Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ..., Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125. Examining the AD Docket You may examine the AD.... FOR FURTHER INFORMATION CONTACT: James Gray, Aerospace Engineer, Engine & Propeller Directorate,...

  19. Potential disturbance interactions with a single IGV in an F109 turbofan engine

    NASA Astrophysics Data System (ADS)

    Kirk, Joel F.

    A common cause of aircraft engine failure is the high cycle fatigue of engine blades and stators. One of the primary causes of these failures is due to blade row interactions, which cause an aerodynamic excitation to be resonant with a mechanical natural frequency. Traditionally, the primary source of such aerodynamic excitations has been practically limited to viscous wakes from upstream components. However, more advanced designs require that blade rows be very highly loaded and closely spaced. This results in aerodynamic excitation from potential fields of down stream engine components, in addition to the known wake excitations. An experimental investigation of the potential field from the fan of a Honeywell F109 turbofan engine has been completed. The investigation included velocity measurements upstream of the fan, addition of an airfoil shaped probe upstream of the fan on which surface pressure measurements were acquired, and measurement of the velocity in the interaction region between the probe and the fan. This investigation sought to characterize the response on the upstream probe due to the fan potential field and the interaction between a viscous wake and the potential field; as such, all test conditions were for subsonic fan speeds. The results from the collected data show that fan-induced potential disturbances propagate upstream at acoustic velocities, to produce vane surface-pressure amplitudes as high as 40 percent Joel F. Kirk of the inlet, mean total pressure. Further, these fan-induced pressure amplitudes display large variations between the two vane surfaces. An argument is made that the structure of the pressure response is consistent with the presence of two distinct sources of unsteady forcing disturbances. The disturbances on the incoming-rotation-facing surface of the IGV propagated upstream at a different speed than those on the outgoing-rotation-facing surface, indicating that one originated from a rotating source and the other from a

  20. GENENG: A program for calculating design and off-design performance for turbojet and turbofan engines

    NASA Technical Reports Server (NTRS)

    Koenig, R. W.; Fishbach, L. H.

    1972-01-01

    A computer program entitled GENENG employs component performance maps to perform analytical, steady state, engine cycle calculations. Through a scaling procedure, each of the component maps can be used to represent a family of maps (different design values of pressure ratios, efficiency, weight flow, etc.) Either convergent or convergent-divergent nozzles may be used. Included is a complete FORTRAN 4 listing of the program. Sample results and input explanations are shown for one-spool and two-spool turbojets and two-spool separate- and mixed-flow turbofans operating at design and off-design conditions.

  1. Application of the MNA design method to a nonlinear turbofan engine. [multivariable Nyquist array method

    NASA Technical Reports Server (NTRS)

    Leininger, G. G.

    1981-01-01

    Using nonlinear digital simulation as a representative model of the dynamic operation of the QCSEE turbofan engine, a feedback control system is designed by variable frequency design techniques. Transfer functions are generated for each of five power level settings covering the range of operation from approach power to full throttle (62.5% to 100% full power). These transfer functions are then used by an interactive control system design synthesis program to provide a closed loop feedback control using the multivariable Nyquist array and extensions to multivariable Bode diagrams and Nichols charts.

  2. Net thrust calculation sensitivity of an afterburning turbofan engine to variations in input parameters

    NASA Technical Reports Server (NTRS)

    Hughes, D. L.; Ray, R. J.; Walton, J. T.

    1985-01-01

    The calculated value of net thrust of an aircraft powered by a General Electric F404-GE-400 afterburning turbofan engine was evaluated for its sensitivity to various input parameters. The effects of a 1.0-percent change in each input parameter on the calculated value of net thrust with two calculation methods are compared. This paper presents the results of these comparisons and also gives the estimated accuracy of the overall net thrust calculation as determined from the influence coefficients and estimated parameter measurement accuracies.

  3. Abradable compressor and turbine seals, volume 1. [for turbofan engines

    NASA Technical Reports Server (NTRS)

    Sundberg, D. V.; Dennis, R. E.; Hurst, L. G.

    1979-01-01

    The application and advantages of abradable coatings as gas-path seals in a general aviation turbine engine were evaluated for use on the high-pressure compressor, the high-pressure turbine, and the low-pressure turbine shrouds. Topics covered include: (1) the initial selection of candidate materials for interim full-scale engine testing; (2) interim engine testing of the initially selected materials and additional candidate materials; (3) the design of the component required to adapt the hardware to permit full-scale engine testing of the most promising materials; (4) finalization of the fabrication methods used in the manufacture of engine test hardware; and (5) the manufacture of the hardware necessary to support the final full-scale engine tests.

  4. Performance deterioration of commercial high-bypass ratio turbofan engines

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    The results of engine performance deterioration investigations based on historical data, special engine tests, and specific tests to define the influence of flight loads and component clearances on performance are presented. The results of analyses of several damage mechanisms that contribute to performance deterioration such as blade tip rubs, airfoil surface roughness and erosion, and thermal distortion are also included. The significance of these damage mechanisms on component and overall engine performance is discussed.

  5. A Foreign Object Damage Event Detector Data Fusion System for Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Turso, James A.; Litt, Jonathan S.

    2004-01-01

    A Data Fusion System designed to provide a reliable assessment of the occurrence of Foreign Object Damage (FOD) in a turbofan engine is presented. The FOD-event feature level fusion scheme combines knowledge of shifts in engine gas path performance obtained using a Kalman filter, with bearing accelerometer signal features extracted via wavelet analysis, to positively identify a FOD event. A fuzzy inference system provides basic probability assignments (bpa) based on features extracted from the gas path analysis and bearing accelerometers to a fusion algorithm based on the Dempster-Shafer-Yager Theory of Evidence. Details are provided on the wavelet transforms used to extract the foreign object strike features from the noisy data and on the Kalman filter-based gas path analysis. The system is demonstrated using a turbofan engine combined-effects model (CEM), providing both gas path and rotor dynamic structural response, and is suitable for rapid-prototyping of control and diagnostic systems. The fusion of the disparate data can provide significantly more reliable detection of a FOD event than the use of either method alone. The use of fuzzy inference techniques combined with Dempster-Shafer-Yager Theory of Evidence provides a theoretical justification for drawing conclusions based on imprecise or incomplete data.

  6. Separating Turbofan Engine Noise Sources Using Auto and Cross Spectra from Four Microphones

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey Hilton

    2008-01-01

    The study of core noise from turbofan engines has become more important as noise from other sources such as the fan and jet were reduced. A multiple-microphone and acoustic-source modeling method to separate correlated and uncorrelated sources is discussed. The auto- and cross spectra in the frequency range below 1000 Hz are fitted with a noise propagation model based on a source couplet consisting of a single incoherent monopole source with a single coherent monopole source or a source triplet consisting of a single incoherent monopole source with two coherent monopole point sources. Examples are presented using data from a Pratt& Whitney PW4098 turbofan engine. The method separates the low-frequency jet noise from the core noise at the nozzle exit. It is shown that at low power settings, the core noise is a major contributor to the noise. Even at higher power settings, it can be more important than jet noise. However, at low frequencies, uncorrelated broadband noise and jet noise become the important factors as the engine power setting is increased.

  7. A Comparison of Hybrid Approaches for Turbofan Engine Gas Path Fault Diagnosis

    NASA Astrophysics Data System (ADS)

    Lu, Feng; Wang, Yafan; Huang, Jinquan; Wang, Qihang

    2016-09-01

    A hybrid diagnostic method utilizing Extended Kalman Filter (EKF) and Adaptive Genetic Algorithm (AGA) is presented for performance degradation estimation and sensor anomaly detection of turbofan engine. The EKF is used to estimate engine component performance degradation for gas path fault diagnosis. The AGA is introduced in the integrated architecture and applied for sensor bias detection. The contributions of this work are the comparisons of Kalman Filters (KF)-AGA algorithms and Neural Networks (NN)-AGA algorithms with a unified framework for gas path fault diagnosis. The NN needs to be trained off-line with a large number of prior fault mode data. When new fault mode occurs, estimation accuracy by the NN evidently decreases. However, the application of the Linearized Kalman Filter (LKF) and EKF will not be restricted in such case. The crossover factor and the mutation factor are adapted to the fitness function at each generation in the AGA, and it consumes less time to search for the optimal sensor bias value compared to the Genetic Algorithm (GA). In a word, we conclude that the hybrid EKF-AGA algorithm is the best choice for gas path fault diagnosis of turbofan engine among the algorithms discussed.

  8. Automated procedure for developing hybrid computer simulations of turbofan engines. Part 1: General description

    NASA Technical Reports Server (NTRS)

    Szuch, J. R.; Krosel, S. M.; Bruton, W. M.

    1982-01-01

    A systematic, computer-aided, self-documenting methodology for developing hybrid computer simulations of turbofan engines is presented. The methodology that is pesented makes use of a host program that can run on a large digital computer and a machine-dependent target (hybrid) program. The host program performs all the calculations and data manipulations that are needed to transform user-supplied engine design information to a form suitable for the hybrid computer. The host program also trims the self-contained engine model to match specified design-point information. Part I contains a general discussion of the methodology, describes a test case, and presents comparisons between hybrid simulation and specified engine performance data. Part II, a companion document, contains documentation, in the form of computer printouts, for the test case.

  9. 77 FR 74125 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-13

    ... Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska... to prevent failure of OBV ring lock fuel fittings, engine fuel leakage, uncontrolled fire, and damage... failure of OBV ring lock fuel fittings, engine fuel leakage, uncontrolled fire, and damage to the...

  10. 77 FR 23637 - Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-20

    ... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will... that was introduced to the PW4000 engine fleet through service bulletins issued in the year 2000. We..., that was introduced to the PW4000 engine fleet for another reason through service bulletins issued...

  11. 77 FR 40822 - Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-11

    ... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation..., Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the..., Engine & Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803; phone:...

  12. 77 FR 3088 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-23

    .... White, Manager, Engine & Propeller Directorate, Aircraft Certification Service. [FR Doc. 2012-1132 Filed... 3088-3090] [FR Doc No: 2012-1132] DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR..., Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on...

  13. Sensor failure detection system. [for the F100 turbofan engine

    NASA Technical Reports Server (NTRS)

    Beattie, E. C.; Laprad, R. F.; Mcglone, M. E.; Rock, S. M.; Akhter, M. M.

    1981-01-01

    Advanced concepts for detecting, isolating, and accommodating sensor failures were studied to determine their applicability to the gas turbine control problem. Five concepts were formulated based upon such techniques as Kalman filters and a screening process led to the selection of one advanced concept for further evaluation. The selected advanced concept uses a Kalman filter to generate residuals, a weighted sum square residuals technique to detect soft failures, likelihood ratio testing of a bank of Kalman filters for isolation, and reconfiguring of the normal mode Kalman filter by eliminating the failed input to accommodate the failure. The advanced concept was compared to a baseline parameter synthesis technique. The advanced concept was shown to be a viable concept for detecting, isolating, and accommodating sensor failures for the gas turbine applications.

  14. Design concepts for low-cost composite turbofan engine frame

    NASA Technical Reports Server (NTRS)

    Mitchell, S. C.; Stoffer, L. J.

    1980-01-01

    Design concepts for low cost, lightweight composite engine frames were applied to the design requirements for the frame of a commercial, high bypass engine. Four alternative composite frame design concepts identified which consisted of generic type components and subcomponents that could be adapted to use in different locations in the engine and the different engine sizes. A variety of materials and manufacturing methods were projected with a goal for the lowest number of parts at the lowest possible cost. After a preliminary evaluation of all four frame concepts, two designs were selected for an extended design and evaluation which narrowed the final selection down to one frame that was significantly lower in cost and slighty lighter than the other frame. An implementation plan for this lowest cost frame is projected for future development and includes prospects for reducing its weight with proposed unproven, innovative fabrication techniques.

  15. Combined pressure and temperature distortion effects on internal flow of a turbofan engine

    NASA Technical Reports Server (NTRS)

    Braithwaite, W. M.; Soeder, R. H.

    1979-01-01

    An additional data base for improving and verifying a computer simulation developed by an engine manufacturer was obtained. The multisegment parallel compressor simulation was designed to predict the effects of steady-state circumferential inlet total-pressure and total-temperature distortions on the flows into and through a turbofan compression system. It also predicts the degree of distortion that will result in surge of the compressor. The effect of combined 180 deg square-wave distortion patterns of total pressure and total temperature in various relative positions is reported. The observed effects of the combined distortion on a unitary bypass ratio turbofan engine are presented in terms of total and static pressure profiles and total temperature profiles at stations ahead of the inlet guide vanes as well as through the fan-compressor system. These observed profiles are compared with those predicted by the complex multisegment model. The effects of relative position of the two components comprising the combined distortion on the degree resulting in surge are discussed. Certain relative positions required less combined distortion than either a temperature or pressure distortion by itself.

  16. Constrained Kalman Filtering Via Density Function Truncation for Turbofan Engine Health Estimation

    NASA Technical Reports Server (NTRS)

    Simon, Dan; Simon, Donald L.

    2006-01-01

    Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints (which may be based on physical considerations) are often neglected because they do not fit easily into the structure of the Kalman filter. This paper develops an analytic method of incorporating state variable inequality constraints in the Kalman filter. The resultant filter truncates the PDF (probability density function) of the Kalman filter estimate at the known constraints and then computes the constrained filter estimate as the mean of the truncated PDF. The incorporation of state variable constraints increases the computational effort of the filter but significantly improves its estimation accuracy. The improvement is demonstrated via simulation results obtained from a turbofan engine model. The turbofan engine model contains 3 state variables, 11 measurements, and 10 component health parameters. It is also shown that the truncated Kalman filter may be a more accurate way of incorporating inequality constraints than other constrained filters (e.g., the projection approach to constrained filtering).

  17. Study of stator-vane fluctuating pressures in a turbofan engine for static and flight tests

    NASA Astrophysics Data System (ADS)

    Mueller, A. W.

    1984-04-01

    As part of a program to study the fan noise generated from turbofan engines, fluctuating surface pressures induced by fan-rotor wakes were measured on core- and bypass-stator outlet guide vanes of a modified JT15D-1 engine. Tests were conducted with the engine operating on an outdoor test stand and in flight. The amplitudes of pressures measured at fan-rotor blade-passage fundamental frequencies were generally higher and appeared less stable for the static tests than for the flight tests. Fluctuating pressures measured at the blade-passage frequency of the high-speed core compressor were interpreted to be acoustic; however, disturbance trace velocities for either the convected rotor wakes or acoustic pressures were difficult to interpret because of the complex environment.

  18. Tests of a D vented thrust deflecting nozzle behind a simulated turbofan engine

    NASA Technical Reports Server (NTRS)

    Watson, T. L.

    1982-01-01

    A D vented thrust deflecting nozzle applicable to subsonic V/STOL aircraft was tested behind a simulated turbofan engine in the verticle thrust stand. Nozzle thrust, fan operating characteristics, nozzle entrance conditions, and static pressures were measured. Nozzle performance was measured for variations in exit area and thrust deflection angle. Six core nozzle configurations, the effect of core exit axial location, mismatched core and fan stream nozzle pressure ratios, and yaw vane presence were evaluated. Core nozzle configuration affected performance at normal and engine out operating conditions. Highest vectored nozzle performance resulted for a given exit area when core and fan stream pressure were equal. Its is concluded that high nozzle performance can be maintained at both normal and engine out conditions through control of the nozzle entrance Mach number with a variable exit area.

  19. Multiplexed Predictive Control of a Large Commercial Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Richter, hanz; Singaraju, Anil; Litt, Jonathan S.

    2008-01-01

    Model predictive control is a strategy well-suited to handle the highly complex, nonlinear, uncertain, and constrained dynamics involved in aircraft engine control problems. However, it has thus far been infeasible to implement model predictive control in engine control applications, because of the combination of model complexity and the time allotted for the control update calculation. In this paper, a multiplexed implementation is proposed that dramatically reduces the computational burden of the quadratic programming optimization that must be solved online as part of the model-predictive-control algorithm. Actuator updates are calculated sequentially and cyclically in a multiplexed implementation, as opposed to the simultaneous optimization taking place in conventional model predictive control. Theoretical aspects are discussed based on a nominal model, and actual computational savings are demonstrated using a realistic commercial engine model.

  20. Reverse thrust performance of the QCSEE variable pitch turbofan engine

    NASA Technical Reports Server (NTRS)

    Samanich, N. E.; Reemsnyder, D. C.; Blodmer, H. E.

    1980-01-01

    Results of steady state reverse and forward to reverse thrust transient performance tests are presented. The original quiet, clean, short haul, experimental engine four segment variable fan nozzle was retested in reverse and compared with a continuous, 30 deg half angle conical exlet. Data indicated that the significantly more stable, higher pressure recovery flow with the fixed 30 deg exlet resulted in lower engine vibrations, lower fan blade stress, and approximately a 20 percent improvement in reverse thrust. Objective reverse thrust of 35 percent of takeoff thrust was reached. Thrust response of less than 1.5 sec was achieved for the approach and the takeoff to reverse thrust transients.

  1. 77 FR 32009 - Airworthiness Directives; Honeywell International, Inc. Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-31

    .... Guidance on performing a detailed functional test of the overspeed system can be found in the applicable... engine and perform a detailed functional test of the overspeed system. Guidance on performing a detailed... functional test of the overspeed system. Guidance on performing a detailed functional test of the...

  2. 78 FR 72552 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-03

    ...: We are adopting a new airworthiness directive (AD) for certain General Electric Company model GEnx... consumed more cyclic life than they would have in revenue flight cycles. These parts were then installed into engines and introduced into revenue service without adjustment to remaining cyclic life. This...

  3. 78 FR 64419 - Airworthiness Directives; Pratt & Whitney Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-29

    .... Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except... caused the engine cowl doors to break open, which resulted in damage to the underside of the airplane's... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3)...

  4. 77 FR 58471 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ... certain part number (P/N) fan mid shafts (FMS) for cracks. This AD was prompted by a report of an FMS failure and a report of a crack found in another FMS. We are issuing this AD to prevent failure of the FMS..., 2012, we received a report of a GEnx-1B engine failure installed on a Boeing 787 (B787)...

  5. 76 FR 72348 - Airworthiness Directives; Pratt & Whitney Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... products of the same type design. Proposed AD Requirements This proposed AD would require establishing a... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will... replacement. (2) Introduction of an engine into a shop solely for removal or replacement of the stage 1...

  6. 76 FR 72353 - Airworthiness Directives; Pratt & Whitney Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... fan drive shaft, and damage to the airplane. DATES: We must receive comments on this proposed AD by... condition, if not corrected, could lead to an engine fire, a fractured fan drive shaft, and damage to the... described previously is likely to exist or develop in other products of the same type design. Proposed...

  7. 77 FR 14312 - Airworthiness Directives; Honeywell International, Inc. Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-09

    ... FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125. Examining the AD Docket You may... Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in...

  8. 77 FR 4650 - Airworthiness Directives; General Electric Company Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-31

    ... certain publication listed in this AD as of February 22, 2011 (76 FR 6323, February 4, 2011). ADDRESSES... copies of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call...

  9. 77 FR 1043 - Airworthiness Directives; Honeywell International Inc. Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-09

    ... referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803. For information on the availability of this material at the FAA, call (781) 238-7125... 12866, (2) Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR...

  10. 75 FR 12661 - Airworthiness Directives; General Electric Company CF6-45 and CF6-50 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-17

    ...-05-AD; Amendment 39-16240; AD 2010-06-15] RIN 2120-AA64 Airworthiness Directives; General Electric...) for General Electric Company (GE) CF6-45 and CF6-50 series turbofan engines with certain low-pressure.... 39.13 by adding the following new airworthiness directive: 2010-06-15 General Electric...

  11. Turbofan synchrophaser

    SciTech Connect

    Snow, B.H.

    1993-07-06

    A synchronizing system for an aircraft having a master turbofan engine and at least one slave turbofan engine, each of the engines having a fan rotor which rotates independently from a core rotor, the system is described comprising: fuel control means for modulating the fuel flow rate to the slave engine to synchronize the operation of the fan rotors; variable stator vane control means for modulating the position of variable stator vanes within the slave engine to synchronize the operation of the core rotors; means for synchronizing the fan rotors prior to synchronizing the core rotors; the variable rotor vane control means includes means responsive to a core rotor speed error signal having a magnitude indicative of the difference in the core rotor rotational speeds of the master engine and the slave engine to the rotational speed of the slave engine's core rotor through modulation of the position of variable stator vanes within the slave engine; the fuel control means further includes means for altering the phase relationship between the fan rotors of the slave engine and the master engine; the variable stator vane control means further includes means for altering the phase relationship between the core rotors of the slave engine and the master engine; and the means for altering the phase relationship between the core rotors is responsive to a core rotor vibrational phase signal having a magnitude indicative of the difference in the core rotor vibration of the master engine and slave engine to modulate the rotational speed of the drive engine's core rotor through modulation of the position of variable stator vanes within the slave engine.

  12. Turbofan Engine Core Compartment Vent Aerodynamic Configuration Development Methodology

    NASA Technical Reports Server (NTRS)

    Hebert, Leonard J.

    2006-01-01

    This paper presents an overview of the design methodology used in the development of the aerodynamic configuration of the nacelle core compartment vent for a typical Boeing commercial airplane together with design challenges for future design efforts. Core compartment vents exhaust engine subsystem flows from the space contained between the engine case and the nacelle of an airplane propulsion system. These subsystem flows typically consist of precooler, oil cooler, turbine case cooling, compartment cooling and nacelle leakage air. The design of core compartment vents is challenging due to stringent design requirements, mass flow sensitivity of the system to small changes in vent exit pressure ratio, and the need to maximize overall exhaust system performance at cruise conditions.

  13. Modeling of Commercial Turbofan Engine With Ice Crystal Ingestion: Follow-On

    NASA Technical Reports Server (NTRS)

    Jorgenson, Philip C. E.; Veres, Joseph P.; Coennen, Ryan

    2014-01-01

    The occurrence of ice accretion within commercial high bypass aircraft turbine engines has been reported under certain atmospheric conditions. Engine anomalies have taken place at high altitudes that have been attributed to ice crystal ingestion, partially melting, and ice accretion on the compression system components. The result was degraded engine performance, and one or more of the following: loss of thrust control (roll back), compressor surge or stall, and flameout of the combustor. As ice crystals are ingested into the fan and low pressure compression system, the increase in air temperature causes a portion of the ice crystals to melt. It is hypothesized that this allows the ice-water mixture to cover the metal surfaces of the compressor stationary components which leads to ice accretion through evaporative cooling. Ice accretion causes a blockage which subsequently results in the deterioration in performance of the compressor and engine. The focus of this research is to apply an engine icing computational tool to simulate the flow through a turbofan engine and assess the risk of ice accretion. The tool is comprised of an engine system thermodynamic cycle code, a compressor flow analysis code, and an ice particle melt code that has the capability of determining the rate of sublimation, melting, and evaporation through the compressor flow path, without modeling the actual ice accretion. A commercial turbofan engine which has previously experienced icing events during operation in a high altitude ice crystal environment has been tested in the Propulsion Systems Laboratory (PSL) altitude test facility at NASA Glenn Research Center. The PSL has the capability to produce a continuous ice cloud which is ingested by the engine during operation over a range of altitude conditions. The PSL test results confirmed that there was ice accretion in the engine due to ice crystal ingestion, at the same simulated altitude operating conditions as experienced previously in

  14. Modeling of Commercial Turbofan Engine with Ice Crystal Ingestion; Follow-On

    NASA Technical Reports Server (NTRS)

    Jorgenson, Philip C. E.; Veres, Joseph P.; Coennen, Ryan

    2014-01-01

    The occurrence of ice accretion within commercial high bypass aircraft turbine engines has been reported under certain atmospheric conditions. Engine anomalies have taken place at high altitudes that have been attributed to ice crystal ingestion, partially melting, and ice accretion on the compression system components. The result was degraded engine performance, and one or more of the following: loss of thrust control (roll back), compressor surge or stall, and flameout of the combustor. As ice crystals are ingested into the fan and low pressure compression system, the increase in air temperature causes a portion of the ice crystals to melt. It is hypothesized that this allows the ice-water mixture to cover the metal surfaces of the compressor stationary components which leads to ice accretion through evaporative cooling. Ice accretion causes a blockage which subsequently results in the deterioration in performance of the compressor and engine. The focus of this research is to apply an engine icing computational tool to simulate the flow through a turbofan engine and assess the risk of ice accretion. The tool is comprised of an engine system thermodynamic cycle code, a compressor flow analysis code, and an ice particle melt code that has the capability of determining the rate of sublimation, melting, and evaporation through the compressor flow path, without modeling the actual ice accretion. A commercial turbofan engine which has previously experienced icing events during operation in a high altitude ice crystal environment has been tested in the Propulsion Systems Laboratory (PSL) altitude test facility at NASA Glenn Research Center. The PSL has the capability to produce a continuous ice cloud which is ingested by the engine during operation over a range of altitude conditions. The PSL test results confirmed that there was ice accretion in the engine due to ice crystal ingestion, at the same simulated altitude operating conditions as experienced previously in

  15. Near-field sound radiation of fan tones from an installed turbofan aero-engine.

    PubMed

    McAlpine, Alan; Gaffney, James; Kingan, Michael J

    2015-09-01

    The development of a distributed source model to predict fan tone noise levels of an installed turbofan aero-engine is reported. The key objective is to examine a canonical problem: how to predict the pressure field due to a distributed source located near an infinite, rigid cylinder. This canonical problem is a simple representation of an installed turbofan, where the distributed source is based on the pressure pattern generated by a spinning duct mode, and the rigid cylinder represents an aircraft fuselage. The radiation of fan tones can be modelled in terms of spinning modes. In this analysis, based on duct modes, theoretical expressions for the near-field acoustic pressures on the cylinder, or at the same locations without the cylinder, have been formulated. Simulations of the near-field acoustic pressures are compared against measurements obtained from a fan rig test. Also, the installation effect is quantified by calculating the difference in the sound pressure levels with and without the adjacent cylindrical fuselage. Results are shown for the blade passing frequency fan tone radiated at a supersonic fan operating condition. PMID:26428770

  16. Effects of temperature transients at fan inlet of a turbofan engine

    NASA Technical Reports Server (NTRS)

    Abdelwahab, M.

    1977-01-01

    The effects of fan inlet temperature transients on the performance and stability of a turbofan engine were determined. The experiment was conducted at 90 and 74 percent of low-pressure-rotor military speed (9525 rpm) and with fan inlet temperature distortions having circumferential extents of 90 deg, 180 deg, 270 deg, and 360 deg. Temperature transients were controlled by varying the magnitude and rate of change of the inlet temperature rise. The engine response ranged from a momentary compressor pressure disturbance to low-pressure-compressor stall. The compressor distortion limits decreased with decreasing low-pressure-rotor speed and increased with increasing circumferential extent of distortion. Analysis of the data suggests strongly that the distortion limits of the compressor are a function of a critical magnitude of inlet temperature rise and are independent of the temperature rise rate.

  17. Low-cost directionally-solidified turbine blades, volume 2. [TFE731-3 turbofan engine

    NASA Technical Reports Server (NTRS)

    Dennis, R. E.; Hoppin, G. S., III; Hurst, L. G.

    1979-01-01

    An endothermically heated technology was used to manufacture low cost, directionally solidified, uncooled nickel-alloy blades for the TFE731-3 turbofan engine. The MAR-M 247 and MER-M 100+Hf blades were finish processed through heat treatment, machining, and coating operations prior to 150 hour engine tests consisting of the following sequences: (1) 50 hours of simulated cruise cycling (high fatigue evaluation); (2) 50 hours at the maximum continuous power rating (stress rupture endurance (low cycle fatigue). None of the blades visually showed any detrimental effects from the test. This was verified by post test metallurgical evaluation. The specific fuel consumption was reduced by 2.4% with the uncooled blades.

  18. Real-time simulation of F100-PW-100 turbofan engine using the hybrid computer

    NASA Technical Reports Server (NTRS)

    Szuch, J. R.; Seldner, K.

    1975-01-01

    A real-time hybrid computer simulation of the F100-PW-100 augmented turbofan is presented. The digital portion of the hybrid computer is used to perform the bivariate function generation associated with modeling the performance of the engine's rotating components. The remaining calculations are performed on the analog computer. Steady state simulation data along with sea level, static, transient data are presented to show that the real-time simulation matches baseline digital simulation results over a wide range of power settings and flight conditions. Steady state simulation data are compared with sea level, experimental data to show that the real-time hybrid and baseline digital simulations do adequately predict the performance of the actual engine. FORTRAN listings and analog patching diagrams are provided.

  19. Measurement effects on the calculation of in-flight thrust for an F404 turbofan engine

    NASA Technical Reports Server (NTRS)

    Conners, Timothy R.

    1989-01-01

    A study was performed that investigates parameter measurement effects on calculated in-flight thrust for the General Electric F404-GE-400 afterburning turbofan engine which powered the X-29A forward-swept wing research aircraft. Net-thrust uncertainty and influence coefficients were calculated and are presented. Six flight conditions were analyzed at five engine power settings each. Results were obtained using the mass flow-temperature and area-pressure thrust calculation methods, both based on the commonly used gas generator technique. Thrust uncertainty was determined using a common procedure based on the use of measurement uncertainty and influence coefficients. The effects of data nonlinearity on the uncertainty calculation procedure were studied and results are presented. The advantages and disadvantages of using this particular uncertainty procedure are discussed. A brief description of the thrust-calculation technique along with the uncertainty calculation procedure is included.

  20. Measurement of far field combustion noise from a turbofan engine using coherence functions

    NASA Technical Reports Server (NTRS)

    Karchmer, A. M.; Reshotko, M.; Montegani, F. J.

    1977-01-01

    Coherence measurements between fluctuating pressure in the combustor of a YF-102 turbofan engine and far-field acoustic pressure were made. The results indicated that a coherent relationship between the combustor pressure and far-field existed only at frequencies below 250 Hz, with the peak occurring near 125 Hz. The coherence functions and the far-field spectra were used to compute the combustor-associated far-field noise in terms of spectra, directivity, and acoustic power, over a range of engine operating conditions. The acoustic results so measured were compared with results obtained by conventional methods, as well as with various semiempirical predictions schemes. Examination of the directivity patterns indicated a peak in the combustion noise near 120 deg (relative to the inlet axis).

  1. Low frequency noise in a quiet, clean, general aviation turbofan engine

    NASA Technical Reports Server (NTRS)

    Huff, R. G.; Groesbeck, D. E.; Goodykoontz, J. H.

    1984-01-01

    A quiet, clean, general aviation, turbofan engine was instrumented to measure the fluctuating pressures in the combustor, turbine exit duct, engine nozzle and the far field. Both a separate flow nozzle and an internal mixer nozzle were tested. The fluctuating pressure data are presented in overall pressure and power levels and in spectral plots. The combustor data are compared to recent theory and found to be in excellent agreement. The results indicate that microphone correction procedures for elevated mean pressures are questionable. Ordinary coherence function analysis suggests the presence of an additional low frequency noise source downstream of the turbine that is due to the turbine itself. Low frequency narrowband data and coherence function analysis are presented.

  2. Exhaust-Gas Pressure and Temperature Survey of F404-GE-400 Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Walton, James T.; Burcham, Frank W., Jr.

    1986-01-01

    An exhaust-gas pressure and temperature survey of the General Electric F404-GE-400 turbofan engine was conducted in the altitude test facility of the NASA Lewis Propulsion System Laboratory. Traversals by a survey rake were made across the exhaust-nozzle exit to measure the pitot pressure and total temperature. Tests were performed at Mach 0.87 and a 24,000-ft altitude and at Mach 0.30 and a 30,000-ft altitude with various power settings from intermediate to maximum afterburning. Data yielded smooth pressure and temperature profiles with maximum jet temperatures approximately 1.4 in. inside the nozzle edge and maximum jet temperatures from 1 to 3 in. inside the edge. A low-pressure region located exactly at engine center was noted. The maximum temperature encountered was 3800 R.

  3. Possible Mechanisms for Turbofan Engine Ice Crystal Icing at High Altitude

    NASA Technical Reports Server (NTRS)

    Tsao, Jen-Ching; Struk, Peter M.; Oliver, Michael J.

    2016-01-01

    A thermodynamic model is presented to describe possible mechanisms of ice formation on unheated surfaces inside a turbofan engine compression system from fully glaciated ice crystal clouds often formed at high altitude near deep convective weather systems. It is shown from the analysis that generally there could be two distinct types of ice formation: (1) when the "surface freezing fraction" is in the range of 0 to 1, dominated by the freezing of water melt from fully or partially melted ice crystals, the ice structure is formed from accretion with strong adhesion to the surface, and (2) when the "surface melting fraction" is the range of 0 to 1, dominated by the further melting of ice crystals, the ice structure is formed from accumulation of un-melted ice crystals with relatively weak bonding to the surface. The model captures important qualitative trends of the fundamental ice-crystal icing phenomenon reported earlier (Refs. 1 and 2) from the research collaboration work by NASA and the National Research Council (NRC) of Canada. Further, preliminary analysis of test data from the 2013 full scale turbofan engine ice crystal icing test (Ref. 3) conducted in the NASA Glenn Propulsion Systems Laboratory (PSL) has also suggested that (1) both types of ice formation occurred during the test, and (2) the model has captured some important qualitative trend of turning on (or off) the ice crystal ice formation process in the tested engine low pressure compressor (LPC) targeted area under different icing conditions that ultimately would lead to (or suppress) an engine core roll back (RB) event.

  4. Possible Mechanisms for Turbofan Engine Ice Crystal Icing at High Altitude

    NASA Technical Reports Server (NTRS)

    Tsao, Jen-Ching; Struk, Peter M.; Oliver, Michael

    2014-01-01

    A thermodynamic model is presented to describe possible mechanisms of ice formation on unheated surfaces inside a turbofan engine compression system from fully glaciated ice crystal clouds often formed at high altitude near deep convective weather systems. It is shown from the analysis that generally there could be two distinct types of ice formation: (1) when the "surface freezing fraction" is in the range of 0 to 1, dominated by the freezing of water melt from fully or partially melted ice crystals, the ice structure is formed from accretion with strong adhesion to the surface, and (2) when the "surface melting fraction" is the range of 0 to 1, dominated by the further melting of ice crystals, the ice structure is formed from accumulation of un-melted ice crystals with relatively weak bonding to the surface. The model captures important qualitative trends of the fundamental ice-crystal icing phenomenon reported earlier1,2 from the research collaboration work by NASA and the National Research Council (NRC) of Canada. Further, preliminary analysis of test data from the 2013 full scale turbofan engine ice crystal icing test3 conducted in the NASA Glenn Propulsion Systems Laboratory (PSL) has also suggested that (1) both types of ice formation occurred during the test, and (2) the model has captured some important qualitative trend of turning on (or off) the ice crystal ice formation process in the tested engine low pressure compressor (LPC) targeted area under different icing conditions that ultimately would lead to (or suppress) an engine core roll back (RB) event.

  5. Optical detection of blade flutter. [in YF-100 turbofan engine

    NASA Technical Reports Server (NTRS)

    Nieberding, W. C.; Pollack, J. L.

    1977-01-01

    The paper examines the capabilities of photoelectric scanning (PES) and stroboscopic imagery (SI) as optical monitoring tools for detection of the onset of flutter in the fan blades of an aircraft gas turbine engine. Both optical techniques give visual data in real time as well as video-tape records. PES is shown to be an ideal flutter monitor, since a single cathode ray tube displays the behavior of all the blades in a stage simultaneously. Operation of the SI system continuously while searching for a flutter condition imposes severe demands on the flash tube and affects its reliability, thus limiting its use as a flutter monitor. A better method of operation is to search for flutter with the PES and limit the use of SI to those times when the PES indicates interesting blade activity.

  6. Effect of combined pressure and temperature distortion orientation on high-bypass-ratio turbofan engine stability

    NASA Technical Reports Server (NTRS)

    Soeder, R. H.; Mehalic, C. M.

    1984-01-01

    Total-temperature, static-pressure and total-pressure distributions were measured in the inlet duct upstream of the engine inlet and within the fan and compressor of a YTF34 turbofan engine. Free-stream and boundary layer yaw angle variations were measured between a rotable screen assembly and the engine inlet. Total pressure distortions were generated using three 180 deg extent screens and total temperature distortions were generated using a rotatable hydrogen burner. Reynolds number index upstream of the rotatable screen assembly was maintained at 0.5 (based on the undistorted sectors at station 1, the inlet flow measuring station). The engine mechanical fan speed at sea level condition was rated at 7005 rpm. The engine was tested at a corrected fan speed of 90 percent of rated condition. Yaw angle increased between the rotatable screen assembly and the engine inlet. The largest variation in free-stream and boundary layer yaw angle occurs when the combined distortions are 180 deg out-of-phase. Static-pressure distortion increased exponentially as flow approached the engine. Total-pressure distortions were attenuated between the engine inlet and the compressor exit. Total-temperature distortion persisted through the compressor for all four combined distortions investigated.

  7. Augmentor emissions reduction technology program. [for turbofan engines

    NASA Technical Reports Server (NTRS)

    Colley, W. C.; Kenworthy, M. J.; Bahr, D. W.

    1977-01-01

    Technology to reduce pollutant emissions from duct-burner-type augmentors for use on advanced supersonic cruise aircraft was investigated. Test configurations, representing variations of two duct-burner design concepts, were tested in a rectangular sector rig at inlet temperature and pressure conditions corresponding to takeoff, transonic climb, and supersonic cruise flight conditions. Both design concepts used piloted flameholders to stabilize combustion of lean, premixed fuel/air mixtures. The concepts differed in the flameholder type used. High combustion efficiency (97%) and low levels of emissions (1.19 g/kg fuel) were achieved. The detailed measurements suggested the direction that future development efforts should take to obtain further reductions in emission levels and associated improvements in combustion efficiency over an increased range of temperature rise conditions.

  8. A Demonstration of a Retrofit Architecture for Intelligent Control and Diagnostics of a Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.; Turso, James A.; Shah, Neerav; Sowers, T. Shane; Owen, A. Karl

    2005-01-01

    A retrofit architecture for intelligent turbofan engine control and diagnostics that changes the fan speed command to maintain thrust is proposed and its demonstration in a piloted flight simulator is described. The objective of the implementation is to increase the level of autonomy of the propulsion system, thereby reducing pilot workload in the presence of anomalies and engine degradation due to wear. The main functions of the architecture are to diagnose the cause of changes in the engine s operation, warning the pilot if necessary, and to adjust the outer loop control reference signal in response to the changes. This requires that the retrofit control architecture contain the capability to determine the changed relationship between fan speed and thrust, and the intelligence to recognize the cause of the change in order to correct it or warn the pilot. The proposed retrofit architecture is able to determine the fan speed setting through recognition of the degradation level of the engine, and it is able to identify specific faults and warn the pilot. In the flight simulator it was demonstrated that when degradation is introduced into an engine with standard fan speed control, the pilot needs to take corrective action to maintain heading. Utilizing the intelligent retrofit control architecture, the engine thrust is automatically adjusted to its expected value, eliminating yaw without pilot intervention.

  9. Application of laminar flow control to high-bypass-ratio turbofan engine nacelles

    NASA Technical Reports Server (NTRS)

    Wie, Y. S.; Collier, F. S., Jr.; Wagner, R. D.

    1991-01-01

    Recently, the concept of the application of hybrid laminar flow to modern commercial transport aircraft was successfully flight tested on a Boeing 757 aircraft. In this limited demonstration, in which only part of the upper surface of the swept wing was designed for the attainment of laminar flow, significant local drag reduction was measured. This paper addresses the potential application of this technology to laminarize the external surface of large, modern turbofan engine nacelles which may comprise as much as 5-10 percent of the total wetted area of future commercial transports. A hybrid-laminar-flow-control (HLFC) pressure distribution is specified and the corresponding nacelle geometry is computed utilizing a predictor/corrector design method. Linear stability calculations are conducted to provide predictions of the extent of the laminar boundary layer. Performance studies are presented to determine potential benefits in terms of reduced fuel consumption.

  10. Exhaust emission survey of an F100 afterburning turbofan engine at simulated altitude flight conditions

    NASA Technical Reports Server (NTRS)

    Moss, J. E.; Cullom, R. R.

    1981-01-01

    Emissions of carbon monoxide, total oxides of nitrogen, unburned hydrocarbons, and carbon dioxide from an F100, afterburning, two spool turbofan engine at simulated flight conditions are reported. For each flight condition emission measurements were made for two or three power levels from intermediate power (nonafterburning) through maximum afterburning. The data showed that emissions vary with flight speed, altitude, power level, and radial position across the nozzle. Carbon monoxide emissions were low for intermediate power (nonafterburning) and partial afterburning, but regions of high carbon monoxide were present downstream of the flame holder at maximum afterburning. Unburned hydrocarbon emissions were low for most of the simulated flight conditions. The local NOX concentrations and their variability with power level increased with increasing flight Mach number at constant altitude, and decreased with increasing altitude at constant Mach number. Carbon dioxide emissions were proportional to local fuel air ratio for all conditions.

  11. Analytical investigation of adaptive control of radiated inlet noise from turbofan engines

    NASA Technical Reports Server (NTRS)

    Risi, John D.; Burdisso, Ricardo A.

    1994-01-01

    An analytical model has been developed to predict the resulting far field radiation from a turbofan engine inlet. A feedforward control algorithm was simulated to predict the controlled far field radiation from the destructive combination of fan noise and secondary control sources. Numerical results were developed for two system configurations, with the resulting controlled far field radiation patterns showing varying degrees of attenuation and spillover. With one axial station of twelve control sources and error sensors with equal relative angular positions, nearly global attenuation is achieved. Shifting the angular position of one error sensor resulted in an increase of spillover to the extreme sidelines. The complex control inputs for each configuration was investigated to identify the structure of the wave pattern created by the control sources, giving an indication of performance of the system configuration. It is deduced that the locations of the error sensors and the control source configuration are equally critical to the operation of the active noise control system.

  12. A flight study of tone radiation patterns generated by inlet rods in a small turbofan engine

    NASA Astrophysics Data System (ADS)

    Preisser, J. S.; Silcox, R. J.; Eversman, W.; Parrett, A. V.

    1984-01-01

    This paper presents a flight study of tone radiation patterns from a small turbofan engine and compares results with similar static test stand data and a recently developed radiation theory. An interaction tone was produced by a circumferential array of inlet rods placed just upstream of the fan blades. Overhead and sideline flight directivity patterns showed cut-on of a dominant single mode occurred where predicted and the absence of any other significant circumferential or radial modes. In general, good agreement was found between measured flight and static data, with small differences being attributed to inlet geometry and/or forward speed effects. Good agreement was also obtained between flight data and theory for directivity pattern shape, however, the theory consistently predicted higher values for peak radiation angle over a wide range of frequency.

  13. Improved Finite Element Modeling of the Turbofan Engine Inlet Radiation Problem

    NASA Technical Reports Server (NTRS)

    Roy, Indranil Danda; Eversman, Walter; Meyer, H. D.

    1993-01-01

    Improvements have been made in the finite element model of the acoustic radiated field from a turbofan engine inlet in the presence of a mean flow. The problem of acoustic radiation from a turbofan engine inlet is difficult to model numerically because of the large domain and high frequencies involved. A numerical model with conventional finite elements in the near field and wave envelope elements in the far field has been constructed. By employing an irrotational mean flow assumption, both the mean flow and the acoustic perturbation problem have been posed in an axisymmetric formulation in terms of the velocity potential; thereby minimizing computer storage and time requirements. The finite element mesh has been altered in search of an improved solution. The mean flow problem has been reformulated with new boundary conditions to make it theoretically rigorous. The sound source at the fan face has been modeled as a combination of positive and negative propagating duct eigenfunctions. Therefore, a finite element duct eigenvalue problem has been solved on the fan face and the resulting modal matrix has been used to implement a source boundary condition on the fan face in the acoustic radiation problem. In the post processing of the solution, the acoustic pressure has been evaluated at Gauss points inside the elements and the nodal pressure values have been interpolated from them. This has significantly improved the results. The effect of the geometric position of the transition circle between conventional finite elements and wave envelope elements has been studied and it has been found that the transition can be made nearer to the inlet than previously assumed.

  14. Technology readiness for advanced ducted engines

    SciTech Connect

    Eckardt, D.; Brines, G.L.

    1989-01-01

    The Advanced Ducted Engines (ADEs) currently undergoing development for next-generation passenger aircraft typically possess bypass ratios of the order of 12-25 and specific fuel consumption figures 12-17 percent lower than current advanced turbofans. An extensive technology-readiness program has been mounted on behalf of ADE design definition over the last two years, encompassing among its concerns aircraft/engine-installation interference, low pressure-ratio fan aerodynamics, fan/nacelle interactions (including windmilling and thrust-reversal), acoustic characteristics, transonic-drive turbines, and slender nacelle aerodynamic and mechanical design. Both turbine-driven and geared ADE fans, which may be of single-rotating or contrarotating type, are discussed. 5 refs.

  15. Effects of bleed air extraction on thrust levels on the F404-GE-400 turbofan engine

    NASA Technical Reports Server (NTRS)

    Yuhas, Andrew J.; Ray, Ronald J.

    1992-01-01

    A ground test was performed to determine the effects of compressor bleed flow extraction on the performance of F404-GE-400 afterburning turbofan engines. The two engines were installed in the F/A-18 High Alpha Research Vehicle at the NASA Dryden Flight Research Facility. A specialized bleed ducting system was installed onto the aircraft to control and measure engine bleed airflow while the aircraft was tied down to a thrust measuring stand. The test was conducted on each engine and at various power settings. The bleed air extraction levels analyzed included flow rates above the manufacturer's maximum specification limit. The measured relationship between thrust and bleed flow extraction was shown to be essentially linear at all power settings with an increase in bleed flow causing a corresponding decrease in thrust. A comparison with the F404-GE-400 steady-state engine simulation showed the estimation to be within +/- 1 percent of measured thrust losses for large increases in bleed flow rate.

  16. Gaseous exhaust emissions from a JT8D-109 turbofan engine at simulated cruise flight conditions

    NASA Technical Reports Server (NTRS)

    Diehl, L. A.; Holdeman, J. D.

    1975-01-01

    Gaseous emissions from a JT8D-109 turbofan engine were measured in an altitude facility at four simulated cruise flight conditions: Mach 0.8 at altitudes of 9.1, 10, 7, and 12.2 km and Mach 0.9 at 10.7 km. Engine inlet air temperature was held constant at 283 K for all tests. Emissions measurements were made at nominally 6 cm intervals across the horizontal diameter of the engine exhaust nozzle with a single-point traversing gas sample probe. Measured emissions of decreased with increasing altitude from an emission index of 10.4 to one of 8.3, while carbon monoxide increased with increasing altitude from an emission index of 1.6 to one of 4.4. Unburned hydrocarbon emissions were essentially negligible for all flight conditions. Since the engine inlet air temperatures were not correctly simulated, the NOx emission indices were corrected to true altitude conditions by using correlating parameters for changes in combustor inlet temperature, pressure, and temperature rise. The correction was small at the lowest altitude. At the 10.7 and 12.2 km, Mach 0.8 test conditions the correction decreased the measured values by 1 emission index.

  17. 75 FR 801 - Airworthiness Directives; Rolls-Royce plc RB211-Trent 500, 700, and 800 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-06

    ... requires replacing the fuel-to-oil heat exchanger (FOHE). This proposed AD would require replacing the FOHE..., 553A2-61, 556A2-61, 556B2-61, and 560A2-61 turbofan engines with fuel-to-oil heat exchangers (FOHEs... through Friday, except Federal holidays. Fax: (202) 493-2251. Contact Rolls-Royce plc, P.O. Box 31,...

  18. Estimation of signal coherence threshold and concealed spectral lines applied to detection of turbofan engine combustion noise.

    PubMed

    Miles, Jeffrey Hilton

    2011-05-01

    Combustion noise from turbofan engines has become important, as the noise from sources like the fan and jet are reduced. An aligned and un-aligned coherence technique has been developed to determine a threshold level for the coherence and thereby help to separate the coherent combustion noise source from other noise sources measured with far-field microphones. This method is compared with a statistics based coherence threshold estimation method. In addition, the un-aligned coherence procedure at the same time also reveals periodicities, spectral lines, and undamped sinusoids hidden by broadband turbofan engine noise. In calculating the coherence threshold using a statistical method, one may use either the number of independent records or a larger number corresponding to the number of overlapped records used to create the average. Using data from a turbofan engine and a simulation this paper shows that applying the Fisher z-transform to the un-aligned coherence can aid in making the proper selection of samples and produce a reasonable statistics based coherence threshold. Examples are presented showing that the underlying tonal and coherent broad band structure which is buried under random broadband noise and jet noise can be determined. The method also shows the possible presence of indirect combustion noise. PMID:21568410

  19. Estimation of Signal Coherence Threshold and Concealed Spectral Lines Applied to Detection of Turbofan Engine Combustion Noise

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey Hilton

    2010-01-01

    Combustion noise from turbofan engines has become important, as the noise from sources like the fan and jet are reduced. An aligned and un-aligned coherence technique has been developed to determine a threshold level for the coherence and thereby help to separate the coherent combustion noise source from other noise sources measured with far-field microphones. This method is compared with a statistics based coherence threshold estimation method. In addition, the un-aligned coherence procedure at the same time also reveals periodicities, spectral lines, and undamped sinusoids hidden by broadband turbofan engine noise. In calculating the coherence threshold using a statistical method, one may use either the number of independent records or a larger number corresponding to the number of overlapped records used to create the average. Using data from a turbofan engine and a simulation this paper shows that applying the Fisher z-transform to the un-aligned coherence can aid in making the proper selection of samples and produce a reasonable statistics based coherence threshold. Examples are presented showing that the underlying tonal and coherent broad band structure which is buried under random broadband noise and jet noise can be determined. The method also shows the possible presence of indirect combustion noise. Copyright 2011 Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America.

  20. Engine Concept Study for an Advanced Single-Aisle Transport

    NASA Technical Reports Server (NTRS)

    Guynn, Mark D.; Berton, Jeffrey J.; Fisher, Kenneth L.; Haller, William J.; Tong, Michael; Thurman, Douglas R.

    2009-01-01

    The desire for higher engine efficiency has resulted in the evolution of aircraft gas turbine engines from turbojets, to low bypass ratio, first generation turbofans, to today's high bypass ratio turbofans. Although increased bypass ratio has clear benefits in terms of propulsion system metrics such as specific fuel consumption, these benefits may not translate into aircraft system level benefits due to integration penalties. In this study, the design trade space for advanced turbofan engines applied to a single aisle transport (737/A320 class aircraft) is explored. The benefits of increased bypass ratio and associated enabling technologies such as geared fan drive are found to depend on the primary metrics of interest. For example, bypass ratios at which mission fuel consumption is minimized may not require geared fan technology. However, geared fan drive does enable higher bypass ratio designs which result in lower noise. The results of this study indicate the potential for the advanced aircraft to realize substantial improvements in fuel efficiency, emissions, and noise compared to the current vehicles in this size class.

  1. Experimental clean combustor program, phase 3: Noise measurement addendum. [CF6-50 high bypass turbofan engine noise

    NASA Technical Reports Server (NTRS)

    Doyle, V. L.

    1978-01-01

    The acoustic characteristics of the double annular combustor in a CF6-50 high bypass turbofan engine were investigated. Internal fluctuating pressure measurements were made in the combustor region and in the core exhaust. The transmission loss across the turbine and nozzle was determined from the measurements and compared to previous component results and present theory. The primary noise source location in the combustor was investigated. Spectral comparisons of test rig results were made with the engine results. The measured overall power level was compared with component and engine correlating parameters.

  2. 3D Multistage Simulation of Each Component of the GE90 Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Turner, Mark; Topp, Dave; Veres, Joe

    1999-01-01

    A 3D multistage simulation of each component of the GE90 Turbofan engine has been made. This includes 49 blade rows. A coupled simulation of all blade rows will be made very soon. The simulation is running using two levels of parallelism. The first level is on a blade row basis with information shared using files. The second level is using a grid domain decomposition with information shared using MPI. Timings will be shown for running on the SP2, an SGI Origin and a distributed system of HP workstations. On the HP workstations, the CHIMP version of MPI is used, with queuing supplied by LSF (Load Sharing Facility). A script-based control system is used to ensure reliability. An MPEG movie illustrating the flow simulation of the engine has been created using PV3, a parallel visualization library created by Bob Haimes of MIT. PVM is used to create a virtual machine from 10 HP workstations and display on an SGI workstation. A representative component simulation will be compared to rig data to demonstrate its usefulness in turbomachinery design and analysis.

  3. Measurements and predictions of flyover and static noise of a TF30 afterburning turbofan engine

    NASA Technical Reports Server (NTRS)

    Burcham, F. W., Jr.; Lasagna, P. L.; Oas, S. C.

    1978-01-01

    The noise of the TF30 afterburning turbofan engine in an F-111 airplane was determined from static (ground) and flyover tests. A survey was made to measure the exhaust temperature and velocity profiles for a range of power settings. Comparisons were made between predicted and measured jet mixing, internal, and shock noise. It was found that the noise produced at static conditions was dominated by jet mixing noise, and was adequately predicted by current methods. The noise produced during flyovers exhibited large contributions from internally generated noise in the forward arc. For flyovers with the engine at nonafterburning power, the internal noise, shock noise, and jet mixing noise were accurately predicted. During flyovers with afterburning power settings, however, additional internal noise believed to be due to the afterburning process was evident; its level was as much as 8 decibels above the nonafterburning internal noise. Power settings that produced exhausts with inverted velocity profiles appeared to be slightly less noisy than power settings of equal thrust that produced uniform exhaust velocity profiles both in flight and in static testing.

  4. Time Delay Analysis of Turbofan Engine Direct and Indirect Combustion Noise Sources

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey Hilton

    2008-01-01

    The core noise components of a dual spool turbofan engine were separated by the use of a coherence function. A source location technique based on adjusting the time delay between the combustor pressure sensor signal and the far-field microphone signal to maximize the coherence and remove as much variation of the phase angle with frequency as possible was used. The discovery was made that for the 130o microphone a 90.027 ms time shift worked best for the frequency band from 0 to 200 Hz while a 86.975 ms time shift worked best for the frequency band from 200 to 400 Hz. Hence, the 0 to 200 Hz band signal took more time than the 200 to 400 Hz band signal to travel the same distance. This suggests the 0 to 200 Hz coherent cross spectral density band is partly due to indirect combustion noise attributed to entropy fluctuations, which travel at the flow velocity, interacting with the turbine. The signal in the 200 to 400 Hz frequency band is attributed mostly to direct combustion noise. Results are presented herein for engine power settings of 48, 54, and 60 percent of the maximum power setting

  5. Preliminary design study of a quiet, high flow fan (QHF) stage. [turbofans - quiet engine program

    NASA Technical Reports Server (NTRS)

    Walker, C. L.; Kisner, L. S.; Delaney, R. A.; Beguhn, A. A.; Frye, D. E.

    1974-01-01

    Concepts selected to reduce fan generated noise in a turbofan are presented. Near-sonic flow at the fan inlet to reduce upstream propagated noise and the use of long-chord vanes to reduce downstream noise is discussed. The near-sonic condition at the rotor inlet plane was achieved by designing for high specific mass flow and by maintaining the high flow at reduced power by variable stators and variable fan exhaust nozzle. The long-chord vanes reduce response to unsteady flow. The acoustic design showed that long-chord stators would significantly reduce turbofan source noise and that other stator design parameters have no appreciable effect on noise for the spacing and chord length of the turbofan design. Four rig flow paths studied in the aerodynamic preliminary design are discussed. Noise prediction results indicate that a turbofan powered aircraft would be under federal air regulations levels without any acoustic treatment.

  6. Attenuation of FJ44 Turbofan Engine Noise with a Foam-Metal Liner Installed Over-the-Rotor

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.; Elliott, Dave M.; Jones, Michael G.; Hartley, Thomas C.

    2009-01-01

    A Williams International FJ44-3A 3000-lb thrust class turbofan engine was used as a demonstrator for a Foam-Metal Liner (FML) installed in close proximity to the fan. Two FML designs were tested and compared to the hardwall baseline. Traditional single degree-of-freedom liner designs were also evaluated to provide a comparison. Farfield acoustic levels and limited engine performance results are presented in this paper. The results show that the FML achieved up to 5 dB Acoustic Power Level (PWL) overall attenuation in the forward quadrant, equivalent to the traditional liner design. An earlier report presented the test set-up and conditions.

  7. Spatial correlation in the ambient core noise field of a turbofan engine.

    PubMed

    Miles, Jeffrey Hilton

    2012-06-01

    An acoustic transfer function relating combustion noise and turbine exit noise in the presence of enclosed ambient core noise is investigated using a dynamic system model and an acoustic system model for the particular turbofan engine studied and for a range of operating conditions. Measurements of cross-spectra magnitude and phase between the combustor and turbine exit and auto-spectra at the turbine exit and combustor are used to show the presence of indirect and direct combustion noise over the frequency range of 0-400 Hz. The procedure used evaluates the ratio of direct to indirect combustion noise. The procedure used also evaluates the post-combustion residence time in the combustor which is a factor in the formation of thermal NO(x) and soot in this region. These measurements are masked by the ambient core noise sound field in this frequency range which is observable since the transducers are situated within an acoustic wavelength of one another. An ambient core noise field model based on one and two dimensional spatial correlation functions is used to replicate the spatially correlated response of the pair of transducers. The spatial correlation function increases measured attenuation due to destructive interference and masks the true attenuation of the turbine. PMID:22712936

  8. Core Noise Diagnostics of Turbofan Engine Noise Using Correlation and Coherence Functions

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey H.

    2009-01-01

    Cross-correlation and coherence functions are used to look for periodic acoustic components in turbofan engine combustor time histories, to investigate direct and indirect combustion noise source separation based on signal propagation time delays, and to provide information on combustor acoustics. Using the cross-correlation function, time delays were identified in all cases, clearly indicating the combustor is the source of the noise. In addition, unfiltered and low-pass filtered at 400 Hz signals had a cross-correlation time delay near 90 ms, while the low-pass filtered at less than 400 Hz signals had a cross-correlation time delay longer than 90 ms. Low-pass filtering at frequencies less than 400 Hz partially removes the direct combustion noise signals. The remainder includes the indirect combustion noise signal, which travels more slowly because of the dependence on the entropy convection velocity in the combustor. Source separation of direct and indirect combustion noise is demonstrated by proper use of low-pass filters with the cross-correlation function for a range of operating conditions. The results may lead to a better idea about the acoustics in the combustor and may help develop and validate improved reduced-order physics-based methods for predicting direct and indirect combustion noise.

  9. Application of the Systematic Sensor Selection Strategy for Turbofan Engine Diagnostics

    NASA Technical Reports Server (NTRS)

    Sowers, T. Shane; Kopasakis, George; Simon, Donald L.

    2008-01-01

    The data acquired from available system sensors forms the foundation upon which any health management system is based, and the available sensor suite directly impacts the overall diagnostic performance that can be achieved. While additional sensors may provide improved fault diagnostic performance, there are other factors that also need to be considered such as instrumentation cost, weight, and reliability. A systematic sensor selection approach is desired to perform sensor selection from a holistic system-level perspective as opposed to performing decisions in an ad hoc or heuristic fashion. The Systematic Sensor Selection Strategy is a methodology that optimally selects a sensor suite from a pool of sensors based on the system fault diagnostic approach, with the ability of taking cost, weight, and reliability into consideration. This procedure was applied to a large commercial turbofan engine simulation. In this initial study, sensor suites tailored for improved diagnostic performance are constructed from a prescribed collection of candidate sensors. The diagnostic performance of the best performing sensor suites in terms of fault detection and identification are demonstrated, with a discussion of the results and implications for future research.

  10. Application of the Systematic Sensor Selection Strategy for Turbofan Engine Diagnostics

    NASA Technical Reports Server (NTRS)

    Sowers, T. Shane; Kopasakis, George; Simon, Donald L.

    2008-01-01

    The data acquired from available system sensors forms the foundation upon which any health management system is based, and the available sensor suite directly impacts the overall diagnostic performance that can be achieved. While additional sensors may provide improved fault diagnostic performance there are other factors that also need to be considered such as instrumentation cost, weight, and reliability. A systematic sensor selection approach is desired to perform sensor selection from a holistic system-level perspective as opposed to performing decisions in an ad hoc or heuristic fashion. The Systematic Sensor Selection Strategy is a methodology that optimally selects a sensor suite from a pool of sensors based on the system fault diagnostic approach, with the ability of taking cost, weight and reliability into consideration. This procedure was applied to a large commercial turbofan engine simulation. In this initial study, sensor suites tailored for improved diagnostic performance are constructed from a prescribed collection of candidate sensors. The diagnostic performance of the best performing sensor suites in terms of fault detection and identification are demonstrated, with a discussion of the results and implications for future research.

  11. A Novel Approach for Reducing Rotor Tip-Clearance Induced Noise in Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R.; Li, Fei; Choudhari, Meelan

    2001-01-01

    Rotor tip-clearance induced noise, both in the form of rotor self noise and rotor-stator interaction noise , constitutes a significant component of total fan noise. Innovative yet cost effective techniques to suppress rotor-generated noise are, therefore, of foremost importance for improving the noise signature of turbofan engines. To that end, the feasibility of a passive porous treatment strategy to positively modify the tip-clearance flow field is addressed. The present study is focused on accurate viscous flow calculations of the baseline and the treated rotor flow fields. Detailed comparison between the computed baseline solution and experimental measurements shows excellent agreement. Tip-vortex structure, trajectory, strength, and other relevant aerodynamic quantities are extracted from the computed database. Extensive comparison between the untreated and treated tip-clearance flow fields is performed. The effectiveness of the porous treatment for altering the rotor-tip vortex flow field in general and reducing the intensity of the tip vortex, in particular, is demonstrated. In addition, the simulated flow field for the treated tip clearly shows that substantial reduction in the intensity of both the shear layer roll-up and boundary layer separation on the wall is achieved.

  12. Spatial Correlation in the Ambient Core Noise Field of a Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey Hilton

    2012-01-01

    An acoustic transfer function relating combustion noise and turbine exit noise in the presence of enclosed ambient core noise is investigated using a dynamic system model and an acoustic system model for the particular turbofan engine studied and for a range of operating conditions. Measurements of cross-spectra magnitude and phase between the combustor and turbine exit and auto-spectra at the turbine exit and combustor are used to show the presence of indirect and direct combustion noise over the frequency range of 0 400 Hz. The procedure used evaluates the ratio of direct to indirect combustion noise. The procedure used also evaluates the post-combustion residence time in the combustor which is a factor in the formation of thermal NOx and soot in this region. These measurements are masked by the ambient core noise sound field in this frequency range which is observable since the transducers are situated within an acoustic wavelength of one another. An ambient core noise field model based on one and two dimensional spatial correlation functions is used to replicate the spatially correlated response of the pair of transducers. The spatial correlation function increases measured attenuation due to destructive interference and masks the true attenuation of the turbine.

  13. Tests and analysis of a vented D thrust deflecting nozzle on a turbofan engine. [conducted at the outdoor aerodynamic research facility of the Ames Research Center

    NASA Technical Reports Server (NTRS)

    Roseberg, E. W.

    1982-01-01

    The objectives were to: obtain nozzle performance characteristics in and out of ground effects; demonstrate the compatibility of the nozzle with a turbofan engine; obtain pressure and temperature distributions on the surface of the D vented nozzle; and establish a correlation of the nozzle performance between small scale and large scale models. The test nozzle was a boilerplate model of the MCAIR D vented nozzle configured for operation with a General Electric YTF-34-F5 turbofan engine. The nozzle was configured to provide: a thrust vectoring range of 0 to 115 deg; a yaw vectoring range of 0 to 10 deg; variable nozzle area control; and variable spacing between the core exit and nozzle entrance station. Compatibility between the YTF-34-T5 turbofan engine and the D vented nozzle was demonstrated. Velocity coefficients of 0.96 and greater were obtained for 90 deg of thrust vectoring. The nozzle walls remained cool during all test conditions.

  14. Robust fault detection of turbofan engines subject to adaptive controllers via a Total Measurable Fault Information Residual (ToMFIR) technique.

    PubMed

    Chen, Wen; Chowdhury, Fahmida N; Djuric, Ana; Yeh, Chih-Ping

    2014-09-01

    This paper provides a new design of robust fault detection for turbofan engines with adaptive controllers. The critical issue is that the adaptive controllers can depress the faulty effects such that the actual system outputs remain the pre-specified values, making it difficult to detect faults/failures. To solve this problem, a Total Measurable Fault Information Residual (ToMFIR) technique with the aid of system transformation is adopted to detect faults in turbofan engines with adaptive controllers. This design is a ToMFIR-redundancy-based robust fault detection. The ToMFIR is first introduced and existing results are also summarized. The Detailed design process of the ToMFIRs is presented and a turbofan engine model is simulated to verify the effectiveness of the proposed ToMFIR-based fault-detection strategy.

  15. Broadband Fan Noise Prediction System for Turbofan Engines. Volume 1; Setup_BFaNS User's Manual and Developer's Guide

    NASA Technical Reports Server (NTRS)

    Morin, Bruce L.

    2010-01-01

    Pratt & Whitney has developed a Broadband Fan Noise Prediction System (BFaNS) for turbofan engines. This system computes the noise generated by turbulence impinging on the leading edges of the fan and fan exit guide vane, and noise generated by boundary-layer turbulence passing over the fan trailing edge. BFaNS has been validated on three fan rigs that were tested during the NASA Advanced Subsonic Technology Program (AST). The predicted noise spectra agreed well with measured data. The predicted effects of fan speed, vane count, and vane sweep also agreed well with measurements. The noise prediction system consists of two computer programs: Setup_BFaNS and BFaNS. Setup_BFaNS converts user-specified geometry and flow-field information into a BFaNS input file. From this input file, BFaNS computes the inlet and aft broadband sound power spectra generated by the fan and FEGV. The output file from BFaNS contains the inlet, aft and total sound power spectra from each noise source. This report is the first volume of a three-volume set documenting the Broadband Fan Noise Prediction System: Volume 1: Setup_BFaNS User s Manual and Developer s Guide; Volume 2: BFaNS User's Manual and Developer s Guide; and Volume 3: Validation and Test Cases. The present volume begins with an overview of the Broadband Fan Noise Prediction System, followed by step-by-step instructions for installing and running Setup_BFaNS. It concludes with technical documentation of the Setup_BFaNS computer program.

  16. Broadband Fan Noise Prediction System for Turbofan Engines. Volume 2; BFaNS User's Manual and Developer's Guide

    NASA Technical Reports Server (NTRS)

    Morin, Bruce L.

    2010-01-01

    Pratt & Whitney has developed a Broadband Fan Noise Prediction System (BFaNS) for turbofan engines. This system computes the noise generated by turbulence impinging on the leading edges of the fan and fan exit guide vane, and noise generated by boundary-layer turbulence passing over the fan trailing edge. BFaNS has been validated on three fan rigs that were tested during the NASA Advanced Subsonic Technology Program (AST). The predicted noise spectra agreed well with measured data. The predicted effects of fan speed, vane count, and vane sweep also agreed well with measurements. The noise prediction system consists of two computer programs: Setup_BFaNS and BFaNS. Setup_BFaNS converts user-specified geometry and flow-field information into a BFaNS input file. From this input file, BFaNS computes the inlet and aft broadband sound power spectra generated by the fan and FEGV. The output file from BFaNS contains the inlet, aft and total sound power spectra from each noise source. This report is the second volume of a three-volume set documenting the Broadband Fan Noise Prediction System: Volume 1: Setup_BFaNS User s Manual and Developer s Guide; Volume 2: BFaNS User s Manual and Developer s Guide; and Volume 3: Validation and Test Cases. The present volume begins with an overview of the Broadband Fan Noise Prediction System, followed by step-by-step instructions for installing and running BFaNS. It concludes with technical documentation of the BFaNS computer program.

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

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  18. Preliminary Study of the Fuel Saving Potential of Regenerative Turbofans for Commercial Subsonic Transports. [engine tests

    NASA Technical Reports Server (NTRS)

    Kraft, G. A.

    1975-01-01

    The fuel savings potential of regenerative turbofans was calculated and compared with that of a reference turbofan. At the design altitude of 10.67 km and Mach 0.80, the turbine-inlet-temperature of the regenerative turbofan was fixed at 1700 K while the overall pressure ratio was varied from 10 to 20. The fan pressure ratio was fixed at 1.6 and the bypass ratio varied from 8 to 10. The heat exchanger design parameters such as pressure drop and effectiveness varied from 4 to 8 percent and from 0.80 to 0.90, respectively. Results indicate a fuel savings due to regeneration of 4.1 percent and no change in takeoff gross weight.

  19. Quiet Clean Short-Haul Experimental Engine (QCSEE) Over-The-Wing (OTW) propulsion system test report. Volume 2: Aerodynamics and performance. [engine performance tests to define propulsion system performance on turbofan engines

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The design and testing of the over the wing engine, a high bypass, geared turbofan engine, are discussed. The propulsion system performance is examined for uninstalled performance and installed performance. The fan aerodynamic performance and the D nozzle and reverser thrust performance are evaluated.

  20. Acoustic Database for Turbofan Engine Core-Noise Sources. I; Volume

    NASA Technical Reports Server (NTRS)

    Gordon, Grant

    2015-01-01

    In this program, a database of dynamic temperature and dynamic pressure measurements were acquired inside the core of a TECH977 turbofan engine to support investigations of indirect combustion noise. Dynamic temperature and pressure measurements were recorded for engine gas dynamics up to temperatures of 3100 degrees Fahrenheit and transient responses as high as 1000 hertz. These measurements were made at the entrance of the high pressure turbine (HPT) and at the entrance and exit of the low pressure turbine (LPT). Measurements were made at two circumferential clocking positions. In the combustor and inter-turbine duct (ITD), measurements were made at two axial locations to enable the exploration of time delays. The dynamic temperature measurements were made using dual thin-wire thermocouple probes. The dynamic pressure measurements were made using semi-infinite probes. Prior to the engine test, a series of bench, oven, and combustor rig tests were conducted to characterize the performance of the dual wire temperature probes and to define and characterize the data acquisition systems. A measurement solution for acquiring dynamic temperature and pressure data on the engine was defined. A suite of hardware modifications were designed to incorporate the dynamic temperature and pressure instrumentation into the TECH977 engine. In particular, a probe actuation system was developed to protect the delicate temperature probes during engine startup and transients in order to maximize sensor life. A set of temperature probes was procured and the TECH977 engine was assembled with the suite of new and modified hardware. The engine was tested at four steady state operating speeds, with repeats. Dynamic pressure and temperature data were acquired at each condition for at least one minute. At the two highest power settings, temperature data could not be obtained at the forward probe locations since the mean temperatures exceeded the capability of the probes. The temperature data

  1. Noise predictions of a high bypass turbofan engine using the Lockheed Near-Field Noise Prediction Program

    NASA Technical Reports Server (NTRS)

    Rawls, J. W., Jr.

    1986-01-01

    The prediction of engine noise during cruise using the Near-Field Noise Prediction Program developed by Lockheed is examined. Test conditions were established which simulate the operation of a high bypass turbofan engine under a wide range of operating conditions. These test conditions include variations in altitude, flight Mach number and thrust setting. Based on the results of noise prediction made using the Lockheed program, an evaluation of the impact of these test conditions on the overall sound pressure level(OASPL)and the one-third octave band spectra is made. An evaluation of the sensitivity of flight condition parameters is also made. The primary noise source from a high bypass turbofan was determined to be fan broadband shock noise. This noise source can be expected to be present during normal cruising conditions. When present, fan broadband shock noise usually dominates at all frequencies and all directivity angles. Other noise sources of importance are broadband shock noise from the primary jet, fan noise, fan mixing noise and turbine noise.

  2. Noise predictions of a high bypass turbofan engine using the Lockheed Near-Field Noise Prediction Program

    NASA Astrophysics Data System (ADS)

    Rawls, J. W., Jr.

    1986-07-01

    The prediction of engine noise during cruise using the Near-Field Noise Prediction Program developed by Lockheed is examined. Test conditions were established which simulate the operation of a high bypass turbofan engine under a wide range of operating conditions. These test conditions include variations in altitude, flight Mach number and thrust setting. Based on the results of noise prediction made using the Lockheed program, an evaluation of the impact of these test conditions on the overall sound pressure level(OASPL)and the one-third octave band spectra is made. An evaluation of the sensitivity of flight condition parameters is also made. The primary noise source from a high bypass turbofan was determined to be fan broadband shock noise. This noise source can be expected to be present during normal cruising conditions. When present, fan broadband shock noise usually dominates at all frequencies and all directivity angles. Other noise sources of importance are broadband shock noise from the primary jet, fan noise, fan mixing noise and turbine noise.

  3. Parallel 3D Multi-Stage Simulation of a Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Turner, Mark G.; Topp, David A.

    1998-01-01

    A 3D multistage simulation of each component of a modern GE Turbofan engine has been made. An axisymmetric view of this engine is presented in the document. This includes a fan, booster rig, high pressure compressor rig, high pressure turbine rig and a low pressure turbine rig. In the near future, all components will be run in a single calculation for a solution of 49 blade rows. The simulation exploits the use of parallel computations by using two levels of parallelism. Each blade row is run in parallel and each blade row grid is decomposed into several domains and run in parallel. 20 processors are used for the 4 blade row analysis. The average passage approach developed by John Adamczyk at NASA Lewis Research Center has been further developed and parallelized. This is APNASA Version A. It is a Navier-Stokes solver using a 4-stage explicit Runge-Kutta time marching scheme with variable time steps and residual smoothing for convergence acceleration. It has an implicit K-E turbulence model which uses an ADI solver to factor the matrix. Between 50 and 100 explicit time steps are solved before a blade row body force is calculated and exchanged with the other blade rows. This outer iteration has been coined a "flip." Efforts have been made to make the solver linearly scaleable with the number of blade rows. Enough flips are run (between 50 and 200) so the solution in the entire machine is not changing. The K-E equations are generally solved every other explicit time step. One of the key requirements in the development of the parallel code was to make the parallel solution exactly (bit for bit) match the serial solution. This has helped isolate many small parallel bugs and guarantee the parallelization was done correctly. The domain decomposition is done only in the axial direction since the number of points axially is much larger than the other two directions. This code uses MPI for message passing. The parallel speed up of the solver portion (no 1/0 or body force

  4. Advanced Engineering Fibers.

    ERIC Educational Resources Information Center

    Edie, Dan D.; Dunham, Michael G.

    1987-01-01

    Describes Clemson University's Advanced Engineered Fibers Laboratory, which was established to provide national leadership and expertise in developing the processing equipment and advance fibers necessary for the chemical, fiber, and textile industries to enter the composite materials market. Discusses some of the laboratory's activities in…

  5. Advanced engine study program

    NASA Astrophysics Data System (ADS)

    Masters, A. I.; Galler, D. E.; Denman, T. F.; Shied, R. A.; Black, J. R.; Fierstein, A. R.; Clark, G. L.; Branstrom, B. R.

    1993-06-01

    A design and analysis study was conducted to provide advanced engine descriptions and parametric data for space transfer vehicles. The study was based on an advanced oxygen/hydrogen engine in the 7,500 to 50,000 lbf thrust range. Emphasis was placed on defining requirements for high-performance engines capable of achieving reliable and versatile operation in a space environment. Four variations on the expander cycle were compared, and the advantages and disadvantages of each were assessed. Parametric weight, envelope, and performance data were generated over a range of 7,500 to 50,000 lb thrust and a wide range of chamber pressure and nozzle expansion ratio.

  6. Advanced engine study program

    NASA Technical Reports Server (NTRS)

    Masters, A. I.; Galler, D. E.; Denman, T. F.; Shied, R. A.; Black, J. R.; Fierstein, A. R.; Clark, G. L.; Branstrom, B. R.

    1993-01-01

    A design and analysis study was conducted to provide advanced engine descriptions and parametric data for space transfer vehicles. The study was based on an advanced oxygen/hydrogen engine in the 7,500 to 50,000 lbf thrust range. Emphasis was placed on defining requirements for high-performance engines capable of achieving reliable and versatile operation in a space environment. Four variations on the expander cycle were compared, and the advantages and disadvantages of each were assessed. Parametric weight, envelope, and performance data were generated over a range of 7,500 to 50,000 lb thrust and a wide range of chamber pressure and nozzle expansion ratio.

  7. 76 FR 20229 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 768-60 and Trent 772-60 Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-12

    ... (63 FR 49416, September 16, 1998). We must receive any comments on this AD by May 27, 2011. ADDRESSES... 39-10754 (63 FR 49416, September 16, 1998), for RR RB211-Trent 700 series turbofan engines. That AD... Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in...

  8. 75 FR 52435 - Airworthiness Directives; Pratt & Whitney Canada (P&WC) PW530A, PW545A, and PW545B Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-26

    ... Canada (P&WC) PW530A, PW545A, and PW545B Turbofan Engines AGENCY: Federal Aviation Administration (FAA... requirements affecting flight safety, and we did not precede it by notice and opportunity for public comment... in the Federal Register published on April 11, 2000 (65 FR 19477-78). Authority for This...

  9. 76 FR 255 - Airworthiness Directives; Pratt & Whitney Canada Corp. (P&WC) PW305A and PW305B Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-04

    ... 39-16524 (75 FR 72653, November 26, 2010), currently requires updating the airworthiness limitations section of the engine maintenance manuals for Pratt & Whitney Canada (P&WC) PW305A and PW305B turbofan...-23-AD; Amendment 39-16524; AD 2010-24-05] RIN 2120-AA64 Airworthiness Directives; Pratt &...

  10. Applications of finite element and wave envelope element approximations to turbofan engine noise radiation including flight effects

    NASA Technical Reports Server (NTRS)

    Parrett, A. V.; Eversman, W.

    1984-01-01

    The problem of acoustic radiation from turbofan engine inlets in flow has not lent itself fully to analysis by numerical means because of the large domains and high frequencies involved. The current work has extended the use of finite elements and wave envelope elements, elements which simulate decay and wavelike behaviour in their interpolation functions, from the no-flow case in which they have been proven, to cases incorporating mean flow. By employing an irrotational mean flow assumption, the acoustics problem has been posed in an axisymmetric formulation in terms of acoustic velocity potential, thus minimizing computer solution storage requirements. The results obtained from the numerical procedures agree well with known analytical solutions, static experimental jet engines inflow data, and also with flight test results.

  11. Applications of finite and wave envelope element approximations to acoustic radiation from turbofan engine inlets in flight

    NASA Astrophysics Data System (ADS)

    Parrett, A. V.

    1984-12-01

    The problem of acoustic radiation from turbofan engine inlets in flow has not lent itself fully to analysis by numerical means because of the large domains and high frequencies involved. The use of finite elements and wave envelope elements, elements which simulate decay and wavelike behavior in their interpolation functions were extended from the no-flow case in which they were proven, to cases incorporating mean flow. By employing an irrotational mean flow assumption, the acoustics problem was posed in axisymmetric formulation in terms of acoustic velocity potential, thus minimizing computer solution storage requirements. The results obtained from the numerical procedures agree well with known analytical solutions and static jet engine inflow experimental data. Some discrepancy with flight test data exists but the combined finite element-wave envelope element solution radiation directivity trends are in good agreement with analytical predictions.

  12. Applications of finite element and wave envelope element approximations to turbofan engine noise radiation including flight effects

    NASA Astrophysics Data System (ADS)

    Parrett, A. V.; Eversman, W.

    1984-10-01

    The problem of acoustic radiation from turbofan engine inlets in flow has not lent itself fully to analysis by numerical means because of the large domains and high frequencies involved. The current work has extended the use of finite elements and wave envelope elements, elements which simulate decay and wavelike behaviour in their interpolation functions, from the no-flow case in which they have been proven, to cases incorporating mean flow. By employing an irrotational mean flow assumption, the acoustics problem has been posed in an axisymmetric formulation in terms of acoustic velocity potential, thus minimizing computer solution storage requirements. The results obtained from the numerical procedures agree well with known analytical solutions, static experimental jet engines inflow data, and also with flight test results.

  13. Advancing cardiovascular tissue engineering

    PubMed Central

    Truskey, George A.

    2016-01-01

    Cardiovascular tissue engineering offers the promise of biologically based repair of injured and damaged blood vessels, valves, and cardiac tissue. Major advances in cardiovascular tissue engineering over the past few years involve improved methods to promote the establishment and differentiation of induced pluripotent stem cells (iPSCs), scaffolds from decellularized tissue that may produce more highly differentiated tissues and advance clinical translation, improved methods to promote vascularization, and novel in vitro microphysiological systems to model normal and diseased tissue function. iPSC technology holds great promise, but robust methods are needed to further promote differentiation. Differentiation can be further enhanced with chemical, electrical, or mechanical stimuli. PMID:27303643

  14. Parametric (On-Design) Cycle Analysis for a Separate-Exhaust Turbofan Engine With Interstage Turbine Burner

    NASA Technical Reports Server (NTRS)

    Liew, K. H.; Urip, E.; Yang, S. L.; Siow, Y. K.; Marek, C. J.

    2005-01-01

    Today s modern aircraft is based on air-breathing jet propulsion systems, which use moving fluids as substances to transform energy carried by the fluids into power. Throughout aero-vehicle evolution, improvements have been made to the engine efficiency and pollutants reduction. The major advantages associated with the addition of ITB are an increase in thermal efficiency and reduction in NOx emission. Lower temperature peak in the main combustor results in lower thermal NOx emission and lower amount of cooling air required. This study focuses on a parametric (on-design) cycle analysis of a dual-spool, separate-flow turbofan engine with an Interstage Turbine Burner (ITB). The ITB considered in this paper is a relatively new concept in modern jet engine propulsion. The ITB serves as a secondary combustor and is located between the high- and the low-pressure turbine, i.e., the transition duct. The objective of this study is to use design parameters, such as flight Mach number, compressor pressure ratio, fan pressure ratio, fan bypass ratio, and high-pressure turbine inlet temperature to obtain engine performance parameters, such as specific thrust and thrust specific fuel consumption. Results of this study can provide guidance in identifying the performance characteristics of various engine components, which can then be used to develop, analyze, integrate, and optimize the system performance of turbofan engines with an ITB. Visual Basic program, Microsoft Excel macrocode, and Microsoft Excel neuron code are used to facilitate Microsoft Excel software to plot engine performance versus engine design parameters. This program computes and plots the data sequentially without forcing users to open other types of plotting programs. A user s manual on how to use the program is also included in this report. Furthermore, this stand-alone program is written in conjunction with an off-design program which is an extension of this study. The computed result of a selected design

  15. 78 FR 22168 - Airworthiness Directives; International Aero Engines AG Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-15

    ... published in the Federal Register on January 9, 2013 (78 FR 1776). That NPRM proposed to require the... ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not.... SUMMARY: We are adopting a new airworthiness directive (AD) for certain International Aero Engines AG...

  16. 78 FR 1776 - Airworthiness Directives; International Aero Engines AG Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... and the compressor case flanges. (i) Alternative Methods of Compliance (AMOCs) The Manager, Engine... Executive Park, Burlington, MA 01803. For information on the availability of this material at the FAA, call...'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not...

  17. Advanced Combustion Engineering.

    ERIC Educational Resources Information Center

    Bartholomew, Calvin H.

    1987-01-01

    Describes the development of the Advanced Combustion Engineering Research Center (ACERC), which is a cooperative project of Brigham Young University, the University of Utah, and 25 governmental and industrial research laboratories. Discusses the research objectives, the academic program, the industrial relations and technology transfer program,…

  18. Full-scale altitude engine test of a turbofan exhaust-gas-forced mixer to reduce thrust specific fuel consumption

    NASA Technical Reports Server (NTRS)

    Cullom, R. R.; Johnson, R. L.

    1977-01-01

    The specific fuel consumption of a low-bypass-ratio, confluent-flow, turbofan engine was measured with and without a mixer installed. Tests were conducted for flight Mach numbers from 0.3 to 1.4 and altitudes from 10,670 to 14,630 meters (35,000 to 48,000 ft) for core-stream-to-fan-stream temperature ratios of 2.0 and 2.5 and mixing-length-to-diameter ratios of 0.95 and 1.74. For these test conditions, the reduction in specific fuel consumption varied from 2.5 percent to 4.0 percent. Pressure loss measurements as well as temperature and pressure surveys at the mixer inlet, the mixer exit, and the nozzle inlet were made.

  19. Experimental Clean Combustor Program (ECCP), phase 3. [commercial aircraft turbofan engine tests with double annular combustor

    NASA Technical Reports Server (NTRS)

    Gleason, C. C.; Bahr, D. W.

    1979-01-01

    A double annular advanced technology combustor with low pollutant emission levels was evaluated in a series of CF6-50 engine tests. Engine lightoff was readily obtained and no difficulties were encountered with combustor staging. Engine acceleration and deceleration were smooth, responsive and essentially the same as those obtainable with the CF6-50 combustor. The emission reductions obtained in carbon monoxide, hydrocarbons, and nitrogen oxide levels were 55, 95, and 30 percent, respectively, at an idle power setting of 3.3 percent of takeoff power on an EPA parameter basis. Acceptable smoke levels were also obtained. The exit temperature distribution of the combustor was found to be its major performance deficiency. In all other important combustion system performance aspects, the combustor was found to be generally satisfactory.

  20. Experimental program for the evaluation of turbofan/turboshaft c conversion technology

    NASA Technical Reports Server (NTRS)

    Mcardle, J. G.; Wenzel, L. M.

    1981-01-01

    A TF34 turbofan engine is being modified to produce shaft power from an output coupling on the fan disk when variable inlet guide vanes are closed to reduce fan airflow. The engine, called a convertible engine, could be used on advanced rotorcraft such as X-wing, ABC (Advanced Blade Concept), and Folding Tilt Rotor, and on V/STOL craft in which two engines are cross-coupled. The engine will be tested on an outdoor static test stand at NASA Lewis Research Center. Steady-state tests will be made to measure performance in turbofan, turboshaft, and combined power output modes. Transient tests will be made to determine the response to the engine and a new digital engine control system for several types of rapid changes in thrust and shaft loads. The paper describes the engine modifications, the test facility equipment, proposed testing techniques for several types of tests, and typical test results predicted from engine performance computer programs.

  1. Identification and measurement of combustion noise from a turbofan engine using correlation and coherence techniques. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Karchmer, A. M.

    1977-01-01

    Fluctuating pressure measurements within the combustor and tailpipe of a turbofan engine are made simultaneously with far field acoustic measurements. The pressure measurements within the engine are accomplished with cooled semi-infinite waveguide probes utilizing conventional condenser microphones as the transducers. The measurements are taken over a broad range of engine operating conditions and for 16 far field microphone positions between 10 deg and 160 deg relative to the engine inlet axis. Correlation and coherence techniques are used to determine the relative phase and amplitude relationships between the internal pressures and far field acoustic pressures. The results indicate that the combustor is a low frequency source region for acoustic propagation through the tailpipe and out to the far field. Specifically, it is found that the relation between source pressure and the resulting sound pressure involves a 180 deg phase shift. The latter result is obtained by Fourier transforming the cross correlation function between the source pressure and acoustic pressure after removing the propagation delay time. Further, it is found that the transfer function between the source pressure and acoustic pressure has a magnitude approximately proportional to frequency squared. These results are shown to be consistent with a model using a modified source term in Lighthill's turbulence stress tensor, wherein the fluctuating Reynolds stresses are replaced with the pressure fluctuations due to fluctuating entropy.

  2. Airflow calibration and exhaust pressure/temperature survey of an F404, S/N 215-109, turbofan engine

    NASA Technical Reports Server (NTRS)

    Burns, Maureen E.; Kirchgessner, Thomas A.

    1987-01-01

    A General Electric F-404 turbofan engine was calibrated for thrust and airflow at the NASA Lewis Propulsion System Laboratory in support of future flight tests of the X-29 aircraft. Tests were conducted with and without augmentation, over a range of flight conditions, including the two design points of the airplane. Data obtained during the altitude tests will be used to correct two independent gross thrust calculation routines which will be installed and operated on the airplane to determine in-flight gross thrust. Corrected airflow data as a function of corrected fan speed collapsed onto a single curve. Similarly, trends were observed and defined for both augmented and dry thrust. Overall agreement between measured data and F-404 Engine Spec Deck data was within 2 percent for airflow and 6 percent for thrust. The results of an uncertainty analysis for thrust and airflow is presented. In addition to the thrust calibration, the exhaust gas boundary layer pressure and temperatures were surveyed at selected condition and engine power levels to obtain data for another NASA F-404 program. Test data for these surveys are presented.

  3. Finite element-integral acoustic simulation of JT15D turbofan engine

    NASA Astrophysics Data System (ADS)

    Baumeister, K. J.; Horowitz, S. J.

    1984-07-01

    An iterative finite element integral technique is used to predict the sound field radiated from the JT15D turbofan inlet. The sound field is divided into two regions: the sound field within and near the inlet which is computed using the finite element method and the radiation field beyond the inlet which is calculated using an integral solution technique. The velocity potential formulation of the acoustic wave equation was employed in the program. For some single mode JT15D data, the theory and experiment are in good agreement for the far field radiation pattern as well as suppressor attenuation. Also, the computer program is used to simulate flight effects that cannot be performed on a ground static test stand.

  4. Performance and Weight Estimates for an Advanced Open Rotor Engine

    NASA Technical Reports Server (NTRS)

    Hendricks, Eric S.; Tong, Michael T.

    2012-01-01

    NASA s Environmentally Responsible Aviation Project and Subsonic Fixed Wing Project are focused on developing concepts and technologies which may enable dramatic reductions to the environmental impact of future generation subsonic aircraft. The open rotor concept (also historically referred to an unducted fan or advanced turboprop) may allow for the achievement of this objective by reducing engine fuel consumption. To evaluate the potential impact of open rotor engines, cycle modeling and engine weight estimation capabilities have been developed. The initial development of the cycle modeling capabilities in the Numerical Propulsion System Simulation (NPSS) tool was presented in a previous paper. Following that initial development, further advancements have been made to the cycle modeling and weight estimation capabilities for open rotor engines and are presented in this paper. The developed modeling capabilities are used to predict the performance of an advanced open rotor concept using modern counter-rotating propeller designs. Finally, performance and weight estimates for this engine are presented and compared to results from a previous NASA study of advanced geared and direct-drive turbofans.

  5. Aircraft turbofan noise

    NASA Technical Reports Server (NTRS)

    Groeneweg, J. F.; Rice, E. J.

    1983-01-01

    Turbofan noise generation and suppression in aircraft engines are reviewed. The chain of physical processes which connect unsteady flow interactions with fan blades to far field noise is addressed. Mechanism identification and description, duct propagation, radiation and acoustic suppression are discussed. The experimental technique of fan inflow static tests are discussed. Rotor blade surface pressure and wake velocity measurements aid in the determination of the types and strengths of the generation mechanisms. Approaches to predicting or measuring acoustic mode content, optimizing treatment impedance to maximize attenuation, translating impedance into porous wall structure and interpreting far field directivity patterns are illustrated by comparisons of analytical and experimental results. The interdependence of source and acoustic treatment design to minimize far field noise is emphasized. Area requiring further research are discussed and the relevance of aircraft turbofan results to quieting other turbomachinery installations is addressed.

  6. Aircraft turbofan noise

    NASA Astrophysics Data System (ADS)

    Groeneweg, J. F.; Rice, E. J.

    1987-01-01

    Turbofan noise generation and suppression in aircraft engines are reviewed. The chain of physical processes which connect unsteady flow interactions with fan blades to far field noise is addressed. Mechanism identification and description, duct propagation, radiation, and acoustic suppression are discussed. The experimental techniques of fan inflow static tests are discussed. Rotor blade surface pressure and wake velocity measurements aid in the determination of the types and strengths of the generation mechanisms. Approaches to predicting or measuring acoustic mode content, optimizing treatment impedance to maximize attenuation, translating impedance into porous wall structure, and interpreting far field directivity patterns are illustrated by comparisons of analytical and experimental results. The interdependence of source and acoustic treatment design to minimize far field noise is emphasized. Areas requiring further research are discussed, and the relevance of aircraft turbofan results to quieting other turbomachinery installation is addressed.

  7. Aircraft turbofan noise

    NASA Astrophysics Data System (ADS)

    Groeneweg, J. F.; Rice, E. J.

    1983-03-01

    Turbofan noise generation and suppression in aircraft engines are reviewed. The chain of physical processes which connect unsteady flow interactions with fan blades to far field noise is addressed. Mechanism identification and description, duct propagation, radiation and acoustic suppression are discussed. The experimental technique of fan inflow static tests are discussed. Rotor blade surface pressure and wake velocity measurements aid in the determination of the types and strengths of the generation mechanisms. Approaches to predicting or measuring acoustic mode content, optimizing treatment impedance to maximize attenuation, translating impedance into porous wall structure and interpreting far field directivity patterns are illustrated by comparisons of analytical and experimental results. The interdependence of source and acoustic treatment design to minimize far field noise is emphasized. Area requiring further research are discussed and the relevance of aircraft turbofan results to quieting other turbomachinery installations is addressed.

  8. Study of an advanced General Aviation Turbine Engine (GATE)

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

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

  9. H2-fueled high-bypass turbofan

    NASA Technical Reports Server (NTRS)

    Riple, J. C.

    1992-01-01

    The study developed preliminary design concepts for the exploitation of the properties of LH2 in a turbofan engine intended for air transport use, and showed the benefits which accrue in reduction of aircraf direct operating cost. Design concepts for the engine fuel delivery and control system, including the engine high pressure fuel pump, were developed, and general concept feasibility was shown. For both the engine and the fuel delivery and control system, recommendations were made for the advanced development which is necessary to bring the technology to a state of readiness for design application. The study was of necessity abbreviated in nature: more intensive study of both the engine and fuel delivery and control system is recommended.

  10. Analytical evaluation of the impact of broad specification fuels on high bypass turbofan engine combustors

    NASA Technical Reports Server (NTRS)

    Lohmann, R. P.; Szetela, E. J.; Vranos, A.

    1978-01-01

    The impact of the use of broad specification fuels on the design, performance durability, emissions and operational characteristics of combustors for commercial aircraft gas turbine engines was assessed. Single stage, vorbix and lean premixed prevaporized combustors, in the JT9D and an advanced energy efficient engine cycle were evaluated when operating on Jet A and ERBS (Experimental Referee Broad Specification) fuels. Design modifications, based on criteria evolved from a literature survey, were introduced and their effectiveness at offsetting projected deficiencies resulting from the use of ERBS was estimated. The results indicate that the use of a broad specification fuel such as ERBS, will necessitate significant technology improvements and redesign if deteriorated performance, durability and emissions are to be avoided. Higher radiant heat loads are projected to seriously compromise liner life while the reduced thermal stability of ERBS will require revisions to the engine-airframe fuel system to reduce the thermal stress on the fuel. Smoke and emissions output are projected to increase with the use of broad specification fuels. While the basic geometry of the single stage and vorbix combustors are compatible with the use of ERBS, extensive redesign of the front end of the lean premixed prevaporized burner will be required to achieve satisfactory operation and optimum emissions.

  11. Reduced-Order Modeling and Wavelet Analysis of Turbofan Engine Structural Response Due to Foreign Object Damage "FOD" Events

    NASA Technical Reports Server (NTRS)

    Turso, James A.; Lawrence, Charles; Litt, Jonathan S.

    2007-01-01

    The development of a wavelet-based feature extraction technique specifically targeting FOD-event induced vibration signal changes in gas turbine engines is described. The technique performs wavelet analysis of accelerometer signals from specified locations on the engine and is shown to be robust in the presence of significant process and sensor noise. It is envisioned that the technique will be combined with Kalman filter thermal/ health parameter estimation for FOD-event detection via information fusion from these (and perhaps other) sources. Due to the lack of high-frequency FOD-event test data in the open literature, a reduced-order turbofan structural model (ROM) was synthesized from a finite-element model modal analysis to support the investigation. In addition to providing test data for algorithm development, the ROM is used to determine the optimal sensor location for FOD-event detection. In the presence of significant noise, precise location of the FOD event in time was obtained using the developed wavelet-based feature.

  12. Reduced-Order Modeling and Wavelet Analysis of Turbofan Engine Structural Response Due to Foreign Object Damage (FOD) Events

    NASA Technical Reports Server (NTRS)

    Turso, James; Lawrence, Charles; Litt, Jonathan

    2004-01-01

    The development of a wavelet-based feature extraction technique specifically targeting FOD-event induced vibration signal changes in gas turbine engines is described. The technique performs wavelet analysis of accelerometer signals from specified locations on the engine and is shown to be robust in the presence of significant process and sensor noise. It is envisioned that the technique will be combined with Kalman filter thermal/health parameter estimation for FOD-event detection via information fusion from these (and perhaps other) sources. Due to the lack of high-frequency FOD-event test data in the open literature, a reduced-order turbofan structural model (ROM) was synthesized from a finite element model modal analysis to support the investigation. In addition to providing test data for algorithm development, the ROM is used to determine the optimal sensor location for FOD-event detection. In the presence of significant noise, precise location of the FOD event in time was obtained using the developed wavelet-based feature.

  13. 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.

  14. Advanced expander test bed engine

    NASA Technical Reports Server (NTRS)

    Mitchell, J. P.

    1992-01-01

    The Advanced Expander Test Bed (AETB) is a key element in NASA's Space Chemical Engine Technology Program for development and demonstration of expander cycle oxygen/hydrogen engine and advanced component technologies applicable to space engines as well as launch vehicle upper stage engines. The AETB will be used to validate the high pressure expander cycle concept, study system interactions, and conduct studies of advanced mission focused components and new health monitoring techniques in an engine system environment. The split expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust.

  15. Development of a short length combustor for a supersonic cruise turbofan engine using a 90 deg sector of a full annulus

    NASA Technical Reports Server (NTRS)

    Clements, T. R.

    1972-01-01

    A performance development program has been conducted on a short length, double-annular, ram-induction combustor. The combustor was designed for a large augmented turbofan engine capable of sustained flight speeds up to Mach 3.0. Performance tests were conducted at an inlet temperature and Mach number simulating engine sea level takeoff conditions. At the design temperature rise of 1600 F, combustion efficiency was 100%, pattern factor was 0.20, and combined diffuser-combustor pressure loss was 4.4% or 1.12 times the diffuser inlet velocity head. A temperature rise in excess of 2400 F with a combustion efficiency of 94% was demonstrated.

  16. Exhaust emissions survey of a turbofan engine for flame holder swirl type augmentors at simulated altitude flight conditions

    NASA Technical Reports Server (NTRS)

    Moss, J. E., Jr.

    1981-01-01

    Emissions of carbon dioxide, total oxides of nitrogen, unburned hydrocarbons, and carbon monoxide from an F100 afterburning two spool turbofan engine at simulated flight conditions are reported. Tests were run at Mach 0.8 at altitudes of 10.97 and 13.71 km (36,000 and 45,000 ft), and at Mach 1.2 at 13.71 km (45,000 ft). Emission measurements were made from intermediate power (nonafterburning) through maximum afterburning, using a single point gas sample probe traversed across the horizontal diameter of the exhaust nozzle. The data show that emissions vary with flight speed, altitude, power level, and radial position across the nozzle. Carbon monoxide emissions were low for intermediate and partial afterburning power. Unburned hydrocarbons were near zero for most of the simulated flight conditions. At maximum afterburning, there were regions of NOx deficiency in regions of high CO. The results suggest that the low NOx levels observed in the tests are a result of interaction with high CO in the thermal converter. CO2 emissions were proportional to local fuel air ratio for all test conditions.

  17. 76 FR 64291 - Airworthiness Directives; General Electric Company (GE) Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-18

    ... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation..., Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the... Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive...

  18. 76 FR 65136 - Airworthiness Directives; Rolls-Royce plc (RR) Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-20

    ... FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781- 238-7125. Examining the AD Docket You may... Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive...

  19. 78 FR 2195 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-10

    ..., Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803. For information on the availability of this material at the FAA, call 781-238-7125. Examining the AD Docket You may... INFORMATION CONTACT: Frederick Zink, Aerospace Engineer, Engine Certification Office, FAA, Engine &...

  20. Analysis of turbofan engine performance deterioration and proposed follow-on tests

    NASA Technical Reports Server (NTRS)

    Sallee, G. P.; Kruckenberg, H. D.; Toomey, E. H.

    1975-01-01

    Data and engine parts on in-service JT3D and JT8D engines were analyzed and documented relative to engine deterioration. It is concluded that the fan-compressor system of these engines contributes to the long term engine deterioration. An engine test and instrumentation plan was formulated for a proposed follow-on program. The goal of this program is to verify the above conclusion and to attempt to identify more precisely which components of the fan-compressor system are at fault.

  1. Digital integrated control of a Mach 2.5 mixed-compression supersonic inlet and an augmented mixed-flow turbofan engine

    NASA Technical Reports Server (NTRS)

    Batterton, P. G.; Arpasi, D. J.; Baumbick, R. J.

    1974-01-01

    A digitally implemented integrated inlet-engine control system was designed and tested on a mixed-compression, axisymmetric, Mach 2.5, supersonic inlet with 45 percent internal supersonic area contraction and a TF30-P-3 augmented turbofan engine. The control matched engine airflow to available inlet airflow. By monitoring inlet terminal shock position and over-board bypass door command, the control adjusted engine speed so that in steady state, the shock would be at the desired location and the overboard bypass doors would be closed. During engine-induced transients, such as augmentor light-off and cutoff, the inlet operating point was momentarily changed to a more supercritical point to minimize unstarts. The digital control also provided automatic inlet restart. A variable inlet throat bleed control, based on throat Mach number, provided additional inlet stability margin.

  2. 76 FR 72130 - Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-22

    ... result in an uncontained engine failure and damage to the airplane. Actions Since Existing AD (72 FR..., -7H, -7J, -20, and -20J engines; Adding ECIs for web cooling holes and tierod holes in HPT stage 2 disks installed in JT9D-59A and -70A engines; Adding ECIs for web cooling holes and tierod holes in...

  3. 77 FR 6668 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-09

    ... of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803. For information on the availability of this material at the FAA, call..., Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive...

  4. 75 FR 15321 - Airworthiness Directives; Rolls-Royce plc RB211-Trent 800 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-29

    ... Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park... Register on January 5, 2010 (75 FR 264). That NPRM proposed to correct an unsafe condition for the... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will not have a...

  5. 77 FR 16916 - Airworthiness Directives; Pratt & Whitney (PW)Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ... information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125. Examining the AD Docket You...., Washington, DC 20590. FOR FURTHER INFORMATION CONTACT: Ian Dargin, Aerospace Engineer, Engine &...

  6. 77 FR 26216 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-03

    ..., Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125. Examining the AD Docket You may examine the AD..., Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive...

  7. 78 FR 61171 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ... INFORMATION CONTACT: Robert Green, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller... NPRM was published in the Federal Register on April 5, 2013 (78 FR 20509). The NPRM proposed to correct... support for the NPRM (78 FR 20509, dated April 5, 2013). Request To Be Less Specific About...

  8. Intelligent, Robust Control of Deteriorated Turbofan Engines via Linear Parameter Varying Quadratic Lyapunov Function Design

    NASA Technical Reports Server (NTRS)

    Turso, James A.; Litt, Jonathan S.

    2004-01-01

    A method for accommodating engine deterioration via a scheduled Linear Parameter Varying Quadratic Lyapunov Function (LPVQLF)-Based controller is presented. The LPVQLF design methodology provides a means for developing unconditionally stable, robust control of Linear Parameter Varying (LPV) systems. The controller is scheduled on the Engine Deterioration Index, a function of estimated parameters that relate to engine health, and is computed using a multilayer feedforward neural network. Acceptable thrust response and tight control of exhaust gas temperature (EGT) is accomplished by adjusting the performance weights on these parameters for different levels of engine degradation. Nonlinear simulations demonstrate that the controller achieves specified performance objectives while being robust to engine deterioration as well as engine-to-engine variations.

  9. Advanced Natural Gas Reciprocating Engine(s)

    SciTech Connect

    Pike, Edward

    2014-03-31

    The objective of the Cummins ARES program, in partnership with the US Department of Energy (DOE), is to develop advanced natural gas engine technologies that increase engine system efficiency at lower emissions levels while attaining lower cost of ownership. The goals of the project are to demonstrate engine system achieving 50% Brake Thermal Efficiency (BTE) in three phases, 44%, 47% and 50% (starting baseline efficiency at 36% BTE) and 0.1 g/bhp-hr NOx system out emissions (starting baseline NOx emissions at 2 – 4 g/bhp-hr NOx). Primary path towards above goals include high Brake Mean Effective Pressure (BMEP), improved closed cycle efficiency, increased air handling efficiency and optimized engine subsystems. Cummins has successfully demonstrated each of the phases of this program. All targets have been achieved through application of a combined set of advanced base engine technologies and Waste Heat Recovery from Charge Air and Exhaust streams, optimized and validated on the demonstration engine and other large engines. The following architectures were selected for each Phase: Phase 1: Lean Burn Spark Ignited (SI) Key Technologies: High Efficiency Turbocharging, Higher Efficiency Combustion System. In production on the 60/91L engines. Over 500MW of ARES Phase 1 technology has been sold. Phase 2: Lean Burn Technology with Exhaust Waste Heat Recovery (WHR) System Key Technologies: Advanced Ignition System, Combustion Improvement, Integrated Waste Heat Recovery System. Base engine technologies intended for production within 2 to 3 years Phase 3: Lean Burn Technology with Exhaust and Charge Air Waste Heat Recovery System Key Technologies: Lower Friction, New Cylinder Head Designs, Improved Integrated Waste Heat Recovery System. Intended for production within 5 to 6 years Cummins is committed to the launch of next generation of large advanced NG engines based on ARES technology to be commercialized worldwide.

  10. Collaboration with Williams International to Demonstrate the Characteristics of a Foam-Metal-Liner Installed Over-the-Rotor of a Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel; Elliott, Dave; Jones, Mike; Hartley, Tom

    2008-01-01

    A Williams International FJ44-3A 3000-lb thrust class turbofan engine was used as a demonstrator for foam-metal liner installed in close proximity to the fan. Two foam metal liner designs were tested and compared to the hardwall. Traditional Single-Degree-of-Freedom liner designs were also evaluated to provide a comparison. Normalized information on farfield acoustics is presented in this paper. The results show that up to 5 dB PWL overall attenuation was achieved in the forward quadrant. In general, the foam-metal liners performed better when the fan tip speed was below sonic.

  11. CFD simulations of the flow control performance applied for inlet of low drag high-bypass turbofan engine at cross flow regimes

    NASA Astrophysics Data System (ADS)

    Kursakov, I. A.; Kazhan, E. V.; Lysenkov, A. V.; Savelyev, A. A.

    2016-10-01

    Paper describes the optimization procedure for low cruise drag inlet of high-bypass ratio turbofan engine (HBRE). The critical cross-flow velocity when the flow separation on the lee side of the inlet channel occurs is determined. The effciency of different flow control devices used to improve the flow parameters at inlet section cross flow regime is analyzed. Boundary layer suction, bypass slot and vortex generators are considered. It is shown that flow control devices enlarge the stability range of inlet performance at cross flow regimes.

  12. On the estimation algorithm used in adaptive performance optimization of turbofan engines

    NASA Technical Reports Server (NTRS)

    Espana, Martin D.; Gilyard, Glenn B.

    1993-01-01

    The performance seeking control algorithm is designed to continuously optimize the performance of propulsion systems. The performance seeking control algorithm uses a nominal model of the propulsion system and estimates, in flight, the engine deviation parameters characterizing the engine deviations with respect to nominal conditions. In practice, because of measurement biases and/or model uncertainties, the estimated engine deviation parameters may not reflect the engine's actual off-nominal condition. This factor has a necessary impact on the overall performance seeking control scheme exacerbated by the open-loop character of the algorithm. The effects produced by unknown measurement biases over the estimation algorithm are evaluated. This evaluation allows for identification of the most critical measurements for application of the performance seeking control algorithm to an F100 engine. An equivalence relation between the biases and engine deviation parameters stems from an observability study; therefore, it is undecided whether the estimated engine deviation parameters represent the actual engine deviation or whether they simply reflect the measurement biases. A new algorithm, based on the engine's (steady-state) optimization model, is proposed and tested with flight data. When compared with previous Kalman filter schemes, based on local engine dynamic models, the new algorithm is easier to design and tune and it reduces the computational burden of the onboard computer.

  13. NASA refan program status. [for noise reduction of JT8D turbofan engine

    NASA Technical Reports Server (NTRS)

    Abdalla, K. L.; Yuska, J. A.

    1975-01-01

    The objective of the refan program is to demonstrate the technical feasibility of substantially reducing the noise levels of existing JT8D powered aircraft. The program consists of the design, manufacturing and testing of the refan engines and modified nacelles and airplanes. Experimental testing was completed for the refan engine both at sea level and at altitude conditions. Ground testing for the B727 side- and center-engine installations and flight testing of the DC-9 with refan engines and acoustic nacelles were performed. Preliminary results presented show that substantial noise reductions were achieved.

  14. Advanced rotary engine studies

    NASA Technical Reports Server (NTRS)

    Jones, C.

    1980-01-01

    A review of rotary engine developments relevant to a stratified charge rotary aircraft engine is presented. Advantages in module size and weight, fuel efficiency, reliability, and multi-fuel capability are discussed along with developments in turbocharging, increased mean effective pressure, improved apex seal/trochoid wear surfacing materials, and high strength and temperature aluminum casting alloys. A carbureted prototype aircraft engine is also described.

  15. A simulation study of turbofan engine deterioration estimation using Kalman filtering techniques

    NASA Technical Reports Server (NTRS)

    Lambert, Heather H.

    1991-01-01

    Deterioration of engine components may cause off-normal engine operation. The result is an unecessary loss of performance, because the fixed schedules are designed to accommodate a wide range of engine health. These fixed control schedules may not be optimal for a deteriorated engine. This problem may be solved by including a measure of deterioration in determining the control variables. These engine deterioration parameters usually cannot be measured directly but can be estimated. A Kalman filter design is presented for estimating two performance parameters that account for engine deterioration: high and low pressure turbine delta efficiencies. The delta efficiency parameters model variations of the high and low pressure turbine efficiencies from nominal values. The filter has a design condition of Mach 0.90, 30,000 ft altitude, and 47 deg power level angle (PLA). It was evaluated using a nonlinear simulation of the F100 engine model derivative (EMD) engine, at the design Mach number and altitude over a PLA range of 43 to 55 deg. It was found that known high pressure turbine delta efficiencies of -2.5 percent and low pressure turbine delta efficiencies of -1.0 percent can be estimated with an accuracy of + or - 0.25 percent efficiency with a Kalman filter. If both the high and low pressure turbine are deteriorated, the delta efficiencies of -2.5 percent to both turbines can be estimated with the same accuracy.

  16. 78 FR 77382 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-23

    ...: Partial de-bonding of the Low Pressure Compressor (LPC) Case Ice Impact Panels was reported during engine... the low pressure compressor (LPC) case ice impact panels during an engine shop visit. We are issuing.... This proposed AD was prompted by a report of a partial de-bonding of the low pressure compressor...

  17. 78 FR 71532 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-29

    ... 2007-03-02 requires an ultrasonic inspection (UI) of low-pressure (LP) compressor fan blades for cracks..., 620-15, Tay 650-15, and Tay 651-54 engines, initial and repetitive UIs of LP compressor fan blades. AD 2007-03-02 also requires, for Tay 650-15 and Tay 651-54 engines, UIs of LP compressor fan...

  18. 75 FR 51659 - Airworthiness Directives; Pratt & Whitney Canada Corp. PW617F-E Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ... uncommanded power reduction on one of its engines. Investigation showed that the Fuel Filter Bypass Valve... that introduced a new fuel Filter Bypass Valve Assembly with an improved design poppet to help... uncommanded power reduction on one of its engines. Investigation showed that the Fuel Filter Bypass...

  19. 77 FR 39157 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ... . You may review copies of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material..., Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; email:...

  20. 77 FR 16917 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ... referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803. For information on the availability of this material at the FAA, call 781-238-7125..., Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; email:...

  1. Core noise investigation of the CF6-50 turbofan engine

    NASA Technical Reports Server (NTRS)

    Doyle, V. L.; Moore, M. T.

    1980-01-01

    The contribution of the standard production annular combustor to the far-field noise signature of the CF6-50 engine was investigated. Internal source locations were studied. Transfer functions were determined for selected pairs of combustor sensors and from two internal sensors to the air field. The coherent output power was determined in the far-field measurements, and comparisons of measured overall power level were made with component and engine correlating parameters.

  2. Particle Trajectory and Icing Analysis of the E(sup 3) Turbofan Engine Using LEWICE3D Version 3

    NASA Technical Reports Server (NTRS)

    Bidwell, Colin S.

    2011-01-01

    Particle trajectory and ice shape calculations were made for the Energy Efficient Engine (E(sup 3)) using the LEWICE3D Version 3 software. The particle trajectory and icing computations were performed using the new "block-to-block" collection efficiency method which has been incorporated into the LEWICE3D Version 3 software. The E(sup 3) was developed by NASA and GE in the early 1980 s as a technology demonstrator and is representative of a modern high bypass turbofan engine. The E(sup 3) flow field was calculated using the NASA Glenn ADPAC turbomachinery flow solver. Computations were performed for the low pressure compressor of the E(sup 3) for a Mach 0.8 cruise condition at 11,887 m assuming a standard warm day for three drop sizes and two drop distributions typically used in aircraft design and certification. Particle trajectory computations were made for water drop sizes of 5, 20, and 100 microns. Particle trajectory and ice shape predictions were made for a 20 micron Langmuir-D distribution and for a 92 mm Super-cooled Large Droplet (SLD) distribution with and without splashing effects for a Liquid Water Content (LWC) of 0.3 g/cu m and an icing time of 30 min. The E3 fan and spinner combination proved to be an effective ice removal mechanism as they removed greater than 36 percent of the mass entering the inlet for the icing cases. The maximum free stream catch fraction for the fan and spinner combination was 0.60 while that on the elements downstream of the fan was 0.03. The non-splashing trajectory and collection efficiency results showed that as drop size increased impingement rates increased on the spinner and fan leaving less mass to impinge on downstream components. The SLD splashing case yielded more mass downstream of the fan than the SLD non-splashing case due to mass being splashed from the upstream inlet lip, spinner and fan components. The ice shapes generated downstream of the fan were either small or nonexistent due to the small available mass

  3. Dynamic and Transient Performance of Turbofan/Turboshaft Convertible Engine With Variable Inlet Guide Vanes

    NASA Technical Reports Server (NTRS)

    McArdle, Jack G.; Barth, Richard L.; Wenzel, Leon M.; Biesiadny, Thomas J.

    1996-01-01

    A convertible engine called the CEST TF34, using the variable inlet guide vane method of power change, was tested on an outdoor stand at the NASA Lewis Research Center with a waterbrake dynamometer for the shaft load. A new digital electronic system, in conjunction with a modified standard TF34 hydromechanical fuel control, kept engine operation stable and safely within limits. All planned testing was completed successfully. Steady-state performance and acoustic characteristics were reported previously and are referenced. This report presents results of transient and dynamic tests. The transient tests measured engine response to several rapid changes in thrust and torque commands at constant fan (shaft) speed. Limited results from dynamic tests using the pseudorandom binary noise technique are also presented. Performance of the waterbrake dynamometer is discussed in an appendix.

  4. An assessment of the use of antimisting fuel in turbofan engines

    NASA Technical Reports Server (NTRS)

    Fiorentino, A.; Desaro, R.; Franz, T.

    1980-01-01

    The effects of antimisting kerosene on the performance of the components from the fuel system and the combustor of a JT8D aircraft engine were evaluated. The problems associated with antimisting kerosene were identified and the extent of shearing or degradation required to allow the engine components to achieve satisfactory operation were determined. The performance of the combustor was assessed in a high pressure facility and in an altitude relight/cold ignition facility. The performance of the fuel pump and control system was evaluated in an open loop simulation.

  5. An assessment of the use of antimisting fuel in turbofan engines

    NASA Technical Reports Server (NTRS)

    Fiorentino, A. J.; Planell, J. R.

    1983-01-01

    An evaluation was made on the effects of using antimisting kerosene (AMK) on the performance of the components from the fuel system and the combustor of current in service JT8D aircraft engines. The objectives were to identify if there were any problems associated with using antimisting kerosene and to determine the extent of shearing or degradation required to allow the engine components to achieve satisfactory operation. The program consisted of a literature survey and a test program which evaluated the antimisting kerosene fuel in laboratory and bench component testing, and assessed the performance of the combustor in a high pressure facility and in an altitude relight/cold ignition facility.

  6. Full-Scale Turbofan-Engine Turbine-Transfer Function Determination Using Three Internal Sensors

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2012-01-01

    Noise-source separation techniques, using three engine-internal sensors, are applied to existing static-engine test data to determine the turbine transfer function for the currently subdominant combustion noise. The results are used to assess the combustion-noise prediction capability of the Aircraft Noise Prediction Program (ANOPP) and an improvement to the combustion-noise module GECOR is suggested. The work was carried out in response to the NASA Fundamental Aeronautics Subsonic Fixed Wing Program s Reduced-Perceived-Noise Technical Challenge.

  7. 77 FR 13485 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-07

    ... Register on November 25, 2011 (76 FR 72650). That NPRM proposed to correct an unsafe condition for the.... Engine running on the ground is not a flight safety issue. We note, however, that the NPRM (76 FR 72650... of Completing the On-Wing Inspection Since we issued the NPRM (76 FR 72650, November 25, 2011),...

  8. An application of tensor ideas to nonlinear modeling of a turbofan jet engine

    NASA Technical Reports Server (NTRS)

    Klingler, T. A.; Yurkovich, S.; Sain, M. K.

    1982-01-01

    An application of tensor modelling to a digital simulation of NASA's Quiet, Clean, Shorthaul Experimental (QCSE) gas turbine engine is presented. The results show that the tensor algebra offers a universal parametrization which is helpful in conceptualization and identification for plant modelling prior to feedback or for representing scheduled controllers over an operating line.

  9. 75 FR 40757 - Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ... April 11, 2000 (65 FR 19477-78). Examining the AD Docket You may examine the AD docket on the Internet... aerodynamic interaction during engine operation. This interaction results in high-cycle-fatigue cracks in the... exist or develop on other products of this same type design. We are proposing this AD, which...

  10. 78 FR 70489 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... April 11, 2000 (65 FR 19477-78). Costs of Compliance We estimate that this AD would affect 0 engines... Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska to the extent... repair (FCSLR). This AD was prompted by reports of erosion of the leading edge profile of the...

  11. 78 FR 54152 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-03

    ... to the specified products. The NPRM was published in the Federal Register on April 5, 2013 (78 FR...) requested that we correct a date cited in paragraph (c)(4)(i) of the NPRM (78 FR 20505, April 5, 2013) used... NPRM (78 FR 20505, April 5, 2013) estimates that 315 engines of U.S. registry are affected, and that...

  12. 76 FR 67591 - Airworthiness Directives; Rolls-Royce Corporation Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-02

    ..., Small Airplane Directorate, FAA, 2300 E. Devon Ave., Des Plaines, IL 60018; phone: (847) 294-7836; fax... each engine. The average labor rate is $85 per work-hour. We anticipate required parts costs to be $35... ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will...

  13. Application of composite materials to turbofan engine fan exit guide vanes

    NASA Technical Reports Server (NTRS)

    Smith, G. T.

    1980-01-01

    A program was conducted by NASA with the JT9D engine manufacturer to develop a lightweight, cost effective, composite material fan exit guide vane design having satisfactory structural durability for commerical engine use. Based on the results of a previous company supported program, eight graphite/epoxy and graphite-glass/epoxy guide vane designs were evaluated and four were selected for fabrication and testing. Two commercial fabricators each fabricated 13 vanes. Fatigue tests were used to qualify the selected design configurations under nominally dry, 38 C (100 F) and fully wet and 60 C (140 F) environmental conditions. Cost estimates for a production rate of 1000 vanes per month ranged from 1.7 to 2.6 times the cost of an all aluminum vane. This cost is 50 to 80 percent less than the initial program target cost ratio which was 3 times the cost of an aluminum vane. Application to the JT9D commercial engine is projected to provide a weight savings of 236 N (53 lb) per engine.

  14. 75 FR 27491 - Airworthiness Directives; Pratt & Whitney Canada Corp. PW617F-E Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-17

    .... Investigation showed that the Fuel Filter Bypass Valve poppet in the Fuel Oil Heat Exchanger (FOHE) on that... fuel/oil heat exchanger (FOHE) part number (P/ N) 35C4540-01 installed. These engines are installed on... holidays. Fax: (202) 493-2251. Contact Pratt & Whitney Canada Corp., 1000 Marie-Victorin, Longueuil,...

  15. 78 FR 17297 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-21

    ...-to-oil heat exchanger mounts. FAA's Determination We are issuing this AD because we evaluated all the... information identified in this AD, contact Rolls-Royce plc, Corporate Communications, P.O. Box 31, Derby.../contact/civil_team.jsp . You may view this service information at the FAA, Engine & Propeller...

  16. 77 FR 74123 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-13

    ... Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78). Discussion The European... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... proposing this AD to prevent failure of the LPC rotor disc assembly, uncontained engine failure, and...

  17. 77 FR 73268 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ... complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78...'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will not have... prompted by a Trent 900 engine experiencing a high intermediate pressure vibration fault, along with...

  18. 78 FR 5126 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-24

    ..., 2000 (65 FR 19477-78). Authority for This Rulemaking Title 49 of the United States Code specifies the... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... of N2 intermediate pressure rotor vibrations resulting in an engine surge and pilot shut down of...

  19. 78 FR 34605 - Airworthiness Directives; CFM International S.A. Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ... pad ``oil dynamic seal'' assembly. This proposed AD was prompted by 42 events of total loss of engine... inspection to verify re- installation of the handcranking pad cover after removal of the pad cover for maintenance until installation of a handcranking pad oil dynamic seal assembly. This inspection...

  20. 77 FR 40820 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-11

    ... complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA....

  1. 77 FR 66771 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ... complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78... rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will..., Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on...

  2. 78 FR 61168 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ... Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone... apply to the specified products. The NPRM was published in the Federal Register on April 5, 2013 (78 FR... received. Agreement With the AD The Boeing Company expressed support for the NPRM (78 FR 20507, dated...

  3. 78 FR 2644 - Airworthiness Directives; CFM International, S.A. Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-14

    ... Center, International phone: 33 1 64 14 88 66; fax: 33 1 64 79 85 55; email: snecma.csc@snecma.fr . You may view this service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call...

  4. 77 FR 6666 - Airworthiness Directives; CFM International, S.A. Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-09

    ..., International Phone: 33 1 64 14 88 66; Fax: 33 1 64 79 85 55; email: snecma.csc@snecma.fr . You may review copies of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call...

  5. 78 FR 45842 - Airworthiness Directives; CFM International, S. A. Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-30

    ..., International phone: 33 1 64 14 88 66; fax: 33 1 64 79 85 55; email: snecma.csc@snecma.fr . You may view this service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125. Examining...

  6. 78 FR 70198 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-25

    ..., FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781... to the specified products. The NPRM was published in the Federal Register on June 13, 2013 (78 FR... Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska to the...

  7. 78 FR 6749 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-31

    ... at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125. Examining the AD Docket You... & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7754; fax:...

  8. 76 FR 64287 - Airworthiness Directives; General Electric Company CF34-10E Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-18

    ..., Cincinnati, OH 45215, phone: 513-552- 3272; e-mail: geae.aoc@ge.com . Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3)...

  9. An Optimal Orthogonal Decomposition Method for Kalman Filter-Based Turbofan Engine Thrust Estimation

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.

    2007-01-01

    A new linear point design technique is presented for the determination of tuning parameters that enable the optimal estimation of unmeasured engine outputs, such as thrust. The engine's performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters related to each major engine component. Accurate thrust reconstruction depends on knowledge of these health parameters, but there are usually too few sensors to be able to estimate their values. In this new technique, a set of tuning parameters is determined that accounts for degradation by representing the overall effect of the larger set of health parameters as closely as possible in a least squares sense. The technique takes advantage of the properties of the singular value decomposition of a matrix to generate a tuning parameter vector of low enough dimension that it can be estimated by a Kalman filter. A concise design procedure to generate a tuning vector that specifically takes into account the variables of interest is presented. An example demonstrates the tuning parameters ability to facilitate matching of both measured and unmeasured engine outputs, as well as state variables. Additional properties of the formulation are shown to lend themselves well to diagnostics.

  10. An Optimal Orthogonal Decomposition Method for Kalman Filter-Based Turbofan Engine Thrust Estimation

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.

    2007-01-01

    A new linear point design technique is presented for the determination of tuning parameters that enable the optimal estimation of unmeasured engine outputs, such as thrust. The engine s performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters related to each major engine component. Accurate thrust reconstruction depends on knowledge of these health parameters, but there are usually too few sensors to be able to estimate their values. In this new technique, a set of tuning parameters is determined that accounts for degradation by representing the overall effect of the larger set of health parameters as closely as possible in a least-squares sense. The technique takes advantage of the properties of the singular value decomposition of a matrix to generate a tuning parameter vector of low enough dimension that it can be estimated by a Kalman filter. A concise design procedure to generate a tuning vector that specifically takes into account the variables of interest is presented. An example demonstrates the tuning parameters ability to facilitate matching of both measured and unmeasured engine outputs, as well as state variables. Additional properties of the formulation are shown to lend themselves well to diagnostics.

  11. An Optimal Orthogonal Decomposition Method for Kalman Filter-Based Turbofan Engine Thrust Estimation

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.

    2005-01-01

    A new linear point design technique is presented for the determination of tuning parameters that enable the optimal estimation of unmeasured engine outputs such as thrust. The engine s performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters related to each major engine component. Accurate thrust reconstruction depends upon knowledge of these health parameters, but there are usually too few sensors to be able to estimate their values. In this new technique, a set of tuning parameters is determined which accounts for degradation by representing the overall effect of the larger set of health parameters as closely as possible in a least squares sense. The technique takes advantage of the properties of the singular value decomposition of a matrix to generate a tuning parameter vector of low enough dimension that it can be estimated by a Kalman filter. A concise design procedure to generate a tuning vector that specifically takes into account the variables of interest is presented. An example demonstrates the tuning parameters ability to facilitate matching of both measured and unmeasured engine outputs, as well as state variables. Additional properties of the formulation are shown to lend themselves well to diagnostics.

  12. 78 FR 70487 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... FR 19477-78). Costs of Compliance We estimate that this AD will affect 20 engines installed on... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation... contaminated with a steel inclusion. We are issuing this AD to prevent failure of the HP or IP turbine...

  13. Sound propagation elements in evaluation of en route noise of advanced turbofan aircraft

    NASA Technical Reports Server (NTRS)

    Sutherland, Louis C.; Wesler, John

    1990-01-01

    Cruise noise from an advanced turboprop aircraft is reviewed on the basis of available wind tunnel data to estimate the aircraft noise signature at the source. Available analytical models are used to evaluate the sound levels at the ground. The analysis allows reasonable estimates to be made of the community noise levels that might be generated during cruise by such aircraft, provides the basis for preliminary comparisons with available data on noise of existing aircraft during climb and helps to identify the dominant elements of the sound propagation models applicable to this situation.

  14. Sound propagation elements in evaluation of en route noise of advanced turbofan aircraft

    NASA Astrophysics Data System (ADS)

    Sutherland, Louis C.; Wesler, John

    1990-04-01

    Cruise noise from an advanced turboprop aircraft is reviewed on the basis of available wind tunnel data to estimate the aircraft noise signature at the source. Available analytical models are used to evaluate the sound levels at the ground. The analysis allows reasonable estimates to be made of the community noise levels that might be generated during cruise by such aircraft, provides the basis for preliminary comparisons with available data on noise of existing aircraft during climb and helps to identify the dominant elements of the sound propagation models applicable to this situation.

  15. 76 FR 36981 - Airworthiness Directives; Rolls-Royce plc RB211-Trent 500 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-24

    ... the root cause to be carbon blockage of the fuel spray nozzles. The source of the carbon has been... input may cause formation of carbon in a specific region of the RH fuel manifold. As advanced thermal... formation of carbon in the RH fuel manifold constitutes a potentially unsafe condition. To address...

  16. A reflection mechanism for aft fan tone noise from turbofan engines

    NASA Astrophysics Data System (ADS)

    Topol, D. A.; Holhubner, S. C.; Mathews, D. C.

    1987-10-01

    A fan tone noise mechanism is proposed which results from reflections from the fan of forward propagating rotor wake/fan exit guide vane interaction tone noise. These fan noise tones are often more dominant out of the rear than out of the front of an engine. To simulate this effect a simple qualitative prediction model was formulated and a scaled model test program was conducted. Results from each of these investigations are compared with each other and with full-scale engine data. These comparisons substantiate the potential importance of this mechanism. Further support is provided by mode measurement data from full-scale testing. This study concluded that for certain vane/blade ratios and tip Mach numbers the contribution of the reflection noise mechanism is significant.

  17. A microprocessor-based real-time simulator of a turbofan engine

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.; Delaat, John C.; Merrill, Walter C.

    1988-01-01

    A real-time digital simulator of a Pratt and Whitney F 100 engine is discussed. This self-contained unit can operate in an open-loop stand-alone mode or as part of a closed-loop control system. It can also be used in control system design and development. It accepts five analog control inputs and its sixteen outputs are returned as analog signals.

  18. Fluctuating pressures on fan blades of a turbofan engine, flight test investigation

    NASA Astrophysics Data System (ADS)

    Schoenster, J. A.

    1985-02-01

    Miniature pressure transducers were used to measure the fluctuating pressure on the fan blades of a JT15D engine in flight to aid in understanding fan-noise generation. Although the blade pressures can be considered very useful in determining far-field noise sources in the subsonic fan-blade tip speeds, other mechanisms, and as shock waves in the transonic and supersonic fan-blade tip speeds, limit their usefulness in these higher speed ranges.

  19. Computer Program for the Design and Off-Design Performance of Turbojet and Turbofan Engine Cycles

    NASA Technical Reports Server (NTRS)

    Morris, S. J.

    1978-01-01

    The rapid computer program is designed to be run in a stand-alone mode or operated within a larger program. The computation is based on a simplified one-dimensional gas turbine cycle. Each component in the engine is modeled thermo-dynamically. The component efficiencies used in the thermodynamic modeling are scaled for the off-design conditions from input design point values using empirical trends which are included in the computer code. The engine cycle program is capable of producing reasonable engine performance prediction with a minimum of computer execute time. The current computer execute time on the IBM 360/67 for one Mach number, one altitude, and one power setting is about 0.1 seconds. about 0.1 seconds. The principal assumption used in the calculation is that the compressor is operated along a line of maximum adiabatic efficiency on the compressor map. The fluid properties are computed for the combustion mixture, but dissociation is not included. The procedure included in the program is only for the combustion of JP-4, methane, or hydrogen.

  20. Validation of an Integrated Airframe and Turbofan Engine Simulation for Evaluation of Propulsion Control Modes

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.; Sowers, T Shane; Liu, Yuan; Owen, A. Karl; Guo, Ten-Huei

    2015-01-01

    The National Aeronautics and Space Administration (NASA) has developed independent airframe and engine models that have been integrated into a single real-time aircraft simulation for piloted evaluation of propulsion control algorithms. In order to have confidence in the results of these evaluations, the integrated simulation must be validated to demonstrate that its behavior is realistic and that it meets the appropriate Federal Aviation Administration (FAA) certification requirements for aircraft. The paper describes the test procedures and results, demonstrating that the integrated simulation generally meets the FAA requirements and is thus a valid testbed for evaluation of propulsion control modes.

  1. The effects of compressor seventh-stage bleed air extraction on performance of the F100-PW-220 afterburning turbofan engine

    NASA Technical Reports Server (NTRS)

    Evans, Alison B.

    1991-01-01

    A study was conducted to determine the effects of seventh-stage compressor bleed on the performance of the F100 afterburning turbofan engine. The effects of bleed on thrust, specific fuel consumption, fan turbine inlet temperature, bleed total pressure, and bleed total temperature were obtained from the engine manufacturer's status deck computer simulation. These effects were determined for power settings of intermediate, partial afterburning, and maximum afterburning for Mach numbers between 0.6 and 2.2 and for altitudes of 30,000, 40,000, and 50,000 ft. It was found that thrust loss and specific fuel consumption increase were approximately linear functions of bleed flow and, based on a percent-thrust change basis, were approximately independent of power setting.

  2. Extending the Operational Envelope of a Turbofan Engine Simulation into the Sub-Idle Region

    NASA Technical Reports Server (NTRS)

    Chapman, Jeffryes W.; Hamley, Andrew J.; Guo, Ten-Huei; Litt, Jonathan S.

    2016-01-01

    In many non-linear gas turbine simulations, operation in the sub-idle region can lead to model instability. This paper lays out a method for extending the operational envelope of a map based gas turbine simulation to include the sub-idle region. This method develops a multi-simulation solution where the baseline component maps are extrapolated below the idle level and an alternate model is developed to serve as a safety net when the baseline model becomes unstable or unreliable. Sub-idle model development takes place in two distinct operational areas, windmilling/shutdown and purge/cranking/ startup. These models are based on derived steady state operating points with transient values extrapolated between initial (known) and final (assumed) states. Model transitioning logic is developed to predict baseline model sub-idle instability, and transition smoothly and stably to the backup sub-idle model. Results from the simulation show a realistic approximation of sub-idle behavior as compared to generic sub-idle engine performance that allows the engine to operate continuously and stably from shutdown to full power.

  3. Extending the Operational Envelope of a Turbofan Engine Simulation into the Sub-Idle Region

    NASA Technical Reports Server (NTRS)

    Chapman, Jeffryes Walter; Hamley, Andrew J.; Guo, Ten-Huei; Litt, Jonathan S.

    2016-01-01

    In many non-linear gas turbine simulations, operation in the sub-idle region can lead to model instability. This paper lays out a method for extending the operational envelope of a map based gas turbine simulation to include the sub-idle region. This method develops a multi-simulation solution where the baseline component maps are extrapolated below the idle level and an alternate model is developed to serve as a safety net when the baseline model becomes unstable or unreliable. Sub-idle model development takes place in two distinct operational areas, windmilling/shutdown and purge/cranking/startup. These models are based on derived steady state operating points with transient values extrapolated between initial (known) and final (assumed) states. Model transitioning logic is developed to predict baseline model sub-idle instability, and transition smoothly and stably to the backup sub-idle model. Results from the simulation show a realistic approximation of sub-idle behavior as compared to generic sub-idle engine performance that allows the engine to operate continuously and stably from shutdown to full power.

  4. Digital implementation of the TF30-P-3 turbofan engine control

    NASA Technical Reports Server (NTRS)

    Cwynar, D. S.; Batterton, P. G.

    1975-01-01

    The standard hydromechanical control modes for TF30-P-3 engine were implemented on a digital process control computer. Programming methods are described, and a method is presented to solve stability problems associated with fast response dynamic loops contained within the exhaust nozzle control. A modification of the exhaust nozzle control to provide for either velocity or position servoactuation systems is discussed. Transient response of the digital control was evaluated by tests on a real time hybrid simulation of the TF30-P-3 engine. It is shown that the deadtime produced by the calculation time delay between sampling and final output is more significant to transient response than the effects associated with sampling rate alone. For the main fuel control, extended update and calculation times resulted in a lengthened transient response to throttle bursts from idle to intermediate with an increase in high pressure compressor stall margin. Extremely long update intervals of 250 msec could be achieved without instability. Update extension for the exhaust nozzle control resulted in a delayed response of the afterburner light-off detector and exhaust nozzle overshoot with resulting fan oversuppression. Long update times of 150 msec caused failure of the control due to a false indication by the blowout detector.

  5. Aerodynamic Performance of Scale-Model Turbofan Outlet Guide Vanes Designed for Low Noise

    NASA Technical Reports Server (NTRS)

    Hughes, Christopher E.

    2001-01-01

    The design of effective new technologies to reduce aircraft propulsion noise is dependent on an understanding of the noise sources and noise generation mechanisms in the modern turbofan engine. In order to more fully understand the physics of noise in a turbofan engine, a comprehensive aeroacoustic wind tunnel test programs was conducted called the 'Source Diagnostic Test.' The text was cooperative effort between NASA and General Electric Aircraft Engines, as part of the NASA Advanced Subsonic Technology Noise Reduction Program. A 1/5-scale model simulator representing the bypass stage of a current technology high bypass ratio turbofan engine was used in the test. The test article consisted of the bypass fan and outlet guide vanes in a flight-type nacelle. The fan used was a medium pressure ratio design with 22 individual, wide chord blades. Three outlet guide vane design configurations were investigated, representing a 54-vane radial Baseline configuration, a 26-vane radial, wide chord Low Count configuration and a 26-vane, wide chord Low Noise configuration with 30 deg of aft sweep. The test was conducted in the NASA Glenn Research Center 9 by 15-Foot Low Speed Wind Tunnel at velocities simulating the takeoff and approach phases of the aircraft flight envelope. The Source Diagnostic Test had several acoustic and aerodynamic technical objectives: (1) establish the performance of a scale model fan selected to represent the current technology turbofan product; (2) assess the performance of the fan stage with each of the three distinct outlet guide vane designs; (3) determine the effect of the outlet guide vane configuration on the fan baseline performance; and (4) conduct detailed flowfield diagnostic surveys, both acoustic and aerodynamic, to characterize and understand the noise generation mechanisms in a turbofan engine. This paper addresses the fan and stage aerodynamic performance results from the Source Diagnostic Test.

  6. Advances in engineering plastics

    SciTech Connect

    Leonard, L.

    1997-12-01

    New polymers are being commercialized in record numbers, offering the product designer a new realm of possibilities, and promising tough competition to the traditional engineering resins. Most of the growth is in single-site catalyzed resins. Metallocene (and non-metallocene) single-site catalysts enhance polymer architecture to generate highly uniform molecules, and even permit tailoring new categories of polymers. These new materials include the truly unique aliphatic polyketone, syndiotactic polystyrene (SPS); polyethylene naphthalate (PEN) resins; and novel variations of established polymers. This article provides a closer look at these newcomers to the plastics marketplace, with an emphasis on their properties and potential applications.

  7. Advances in water engineering

    SciTech Connect

    Tebbutt, T.H.Y.

    1985-01-01

    Water is the world's most important natural resource and its efficient utilization requires a proper understanding of the multifunctional role of water in modern society. The philosophy of integrating both quality and quantity considerations of water engineering is an essential aspect of optimal use of resources and this book provides a collection of 41 papers to emphasize this philosophy. Each section of the contents includes a state-of-the art review followed by specialist contributions on a specific topic so that the reader can gain an overview of the area as well as being informed about the latest developments in particular aspects of the subject.

  8. Full-Scale Turbofan-Engine Turbine-Transfer Function Determination Using Three Internal Sensors

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    Existing NASA/Honeywell EVNERT full-scale static engine test data is analyzed by using source-separation techniques in order to determine the turbine transfer of the currently sub-dominant combustor noise. The results are used to assess the combustor-noise prediction capability of the Aircraft Noise Prediction Program (ANOPP). Time-series data from three sensors internal to the Honeywell TECH977 research engine is used in the analysis. The true combustor-noise turbine-transfer function is educed by utilizing a new three-signal approach. The resulting narrowband gain factors are compared with the corresponding constant values obtained from two empirical acoustic-turbine-loss formulas. It is found that a simplified Pratt & Whitney formula agrees better with the experimental results for frequencies of practical importance. The 130 deg downstream-direction far-field 1/3-octave sound-pressure levels (SPL) results of Hultgren & Miles are reexamined using a post-correction of their ANOPP predictions for both the total noise signature and the combustion-noise component. It is found that replacing the standard ANOPP turbine-attenuation function for combustion noise with the simplified Pratt & Whitney formula clearly improves the predictions. It is recommended that the GECOR combustion-noise module in ANOPP be updated to allow for a user-selectable switch between the current transmission-loss model and the simplified Pratt & Whitney formula. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The Subsonic Fixed Wing Project's Reduce-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. The reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic.

  9. Core compressor exit stage study. Volume 1: Blading design. [turbofan engines

    NASA Technical Reports Server (NTRS)

    Wisler, D. C.

    1977-01-01

    A baseline compressor test stage was designed as well as a candidate rotor and two candidate stators that have the potential of reducing endwall losses relative to the baseline stage. These test stages are typical of those required in the rear stages of advanced, highly-loaded core compressors. The baseline Stage A is a low-speed model of Stage 7 of the 10 stage AMAC compressor. Candidate Rotor B uses a type of meanline in the tip region that unloads the leading edge and loads the trailing edge relative to the baseline Rotor A design. Candidate Stator B embodies twist gradients in the endwall region. Candidate Stator C embodies airfoil sections near the endwalls that have reduced trailing edge loading relative to Stator A. Tests will be conducted using four identical stages of blading so that the designs described will operate in a true multistage environment.

  10. A proposed Kalman filter algorithm for estimation of unmeasured output variables for an F100 turbofan engine

    NASA Technical Reports Server (NTRS)

    Alag, Gurbux S.; Gilyard, Glenn B.

    1990-01-01

    To develop advanced control systems for optimizing aircraft engine performance, unmeasurable output variables must be estimated. The estimation has to be done in an uncertain environment and be adaptable to varying degrees of modeling errors and other variations in engine behavior over its operational life cycle. This paper represented an approach to estimate unmeasured output variables by explicitly modeling the effects of off-nominal engine behavior as biases on the measurable output variables. A state variable model accommodating off-nominal behavior is developed for the engine, and Kalman filter concepts are used to estimate the required variables. Results are presented from nonlinear engine simulation studies as well as the application of the estimation algorithm on actual flight data. The formulation presented has a wide range of application since it is not restricted or tailored to the particular application described.

  11. Coupling of Helmholtz resonators to improve acoustic liners for turbofan engines at low frequency

    NASA Technical Reports Server (NTRS)

    Dean, L. W.

    1975-01-01

    An analytical and test program was conducted to evaluate means for increasing the effectiveness of low frequency sound absorbing liners for aircraft turbine engines. Three schemes for coupling low frequency absorber elements were considered. These schemes were analytically modeled and their impedance was predicted over a frequency range of 50 to 1,000 Hz. An optimum and two off-optimum designs of the most promising, a parallel coupled scheme, were fabricated and tested in a flow duct facility. Impedance measurements were in good agreement with predicted values and validated the procedure used to transform modeled parameters to hardware designs. Measurements of attenuation for panels of coupled resonators were consistent with predictions based on measured impedance. All coupled resonator panels tested showed an increase in peak attenuation of about 50% and an increase in attenuation bandwidth of one one-third octave band over that measured for an uncoupled panel. These attenuation characteristics equate to about 35% greater reduction in source perceived noise level (PNL), relative to the uncoupled panel, or a reduction in treatment length of about 24% for constant PNL reduction. The increased effectiveness of the coupled resonator concept for attenuation of low frequency broad spectrum noise is demonstrated.

  12. Noise levels from a model turbofan engine with simulated noise control measures applied

    NASA Technical Reports Server (NTRS)

    Hall, David G.; Woodward, Richard P.

    1993-01-01

    A study of estimated full-scale noise levels based on measured levels from the Advanced Ducted Propeller (ADP) sub-scale model is presented. Testing of this model was performed in the NASA Lewis Low Speed Anechoic Wind Tunnel at a simulated takeoff condition of Mach 0.2. Effective Perceived Noise Level (EPNL) estimates for the baseline configuration are documented, and also used as the control case in a study of the potential benefits of two categories of noise control. The effect of active noise control is evaluated by artificially removing various rotor-stator interaction tones. Passive noise control is simulated by applying a notch filter to the wind tunnel data. Cases with both techniques are included to evaluate hybrid active-passive noise control. The results for EPNL values are approximate because the original source data was limited in bandwidth and in sideline angular coverage. The main emphasis is on comparisons between the baseline and configurations with simulated noise control measures.

  13. Development of a Twin-spool Turbofan Engine Simulation Using the Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS)

    NASA Technical Reports Server (NTRS)

    Zinnecker, Alicia M.; Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Johathan S.

    2014-01-01

    The Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS) is a tool that has been developed to allow a user to build custom models of systems governed by thermodynamic principles using a template to model each basic process. Validation of this tool in an engine model application was performed through reconstruction of the Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) (v2) using the building blocks from the T-MATS (v1) library. In order to match the two engine models, it was necessary to address differences in several assumptions made in the two modeling approaches. After these modifications were made, validation of the engine model continued by integrating both a steady-state and dynamic iterative solver with the engine plant and comparing results from steady-state and transient simulation of the T-MATS and C-MAPSS models. The results show that the T-MATS engine model was accurate within 3 of the C-MAPSS model, with inaccuracy attributed to the increased dimension of the iterative solver solution space required by the engine model constructed using the T-MATS library. This demonstrates that, given an understanding of the modeling assumptions made in T-MATS and a baseline model, the T-MATS tool provides a viable option for constructing a computational model of a twin-spool turbofan engine that may be used in simulation studies.

  14. Development of a Twin-Spool Turbofan Engine Simulation Using the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS)

    NASA Technical Reports Server (NTRS)

    Zinnecker, Alicia M.; Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Jonathan S.

    2014-01-01

    The Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) is a tool that has been developed to allow a user to build custom models of systems governed by thermodynamic principles using a template to model each basic process. Validation of this tool in an engine model application was performed through reconstruction of the Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) (v2) using the building blocks from the T-MATS (v1) library. In order to match the two engine models, it was necessary to address differences in several assumptions made in the two modeling approaches. After these modifications were made, validation of the engine model continued by integrating both a steady-state and dynamic iterative solver with the engine plant and comparing results from steady-state and transient simulation of the T-MATS and C-MAPSS models. The results show that the T-MATS engine model was accurate within 3% of the C-MAPSS model, with inaccuracy attributed to the increased dimension of the iterative solver solution space required by the engine model constructed using the T-MATS library. This demonstrates that, given an understanding of the modeling assumptions made in T-MATS and a baseline model, the T-MATS tool provides a viable option for constructing a computational model of a twin-spool turbofan engine that may be used in simulation studies.

  15. Advanced Technology for Engineering Education

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K. (Compiler); Malone, John B. (Compiler)

    1998-01-01

    This document contains the proceedings of the Workshop on Advanced Technology for Engineering Education, held at the Peninsula Graduate Engineering Center, Hampton, Virginia, February 24-25, 1998. The workshop was jointly sponsored by the University of Virginia's Center for Advanced Computational Technology and NASA. Workshop attendees came from NASA, other government agencies, industry and universities. The objectives of the workshop were to assess the status of advanced technologies for engineering education and to explore the possibility of forming a consortium of interested individuals/universities for curriculum reform and development using advanced technologies. The presentations covered novel delivery systems and several implementations of new technologies for engineering education. Certain materials and products are identified in this publication in order to specify adequately the materials and products that were investigated in the research effort. In no case does such identification imply recommendation or endorsement of products by NASA, nor does it imply that the materials and products are the only ones or the best ones available for this purpose. In many cases equivalent materials and products are available and would probably produce equivalent results.

  16. Development in Geared Turbofan Aeroengine

    NASA Astrophysics Data System (ADS)

    Mohd Tobi, A. L.; Ismail, A. E.

    2016-05-01

    This paper looks into the implementation of epicyclic gear system to the aeroengine in order to increase the efficiency of the engine. The improvement made is in the direction of improving fuel consumption, reduction in pollutant gasses and perceived noise. Introduction of epicyclic gear system is capable to achieve bypass ratio of up to 15:1 with the benefits of weight and noise reduction. Radical new aircraft designs and engine installation are being studied to overcome some of the challenges associated with the future geared turbofan and open-rotor engine.

  17. Large Engine Technology (LET) Task XXXVII Low-Bypass Ratio Mixed Turbofan Engine Subsonic Jet Noise Reduction Program Test Report

    NASA Technical Reports Server (NTRS)

    Hauser, Joseph R.; Zysman, Steven H.; Barber, Thomas J.

    2001-01-01

    NASA Glenn Research Center supported a three year effort to develop the technology for reducing jet noise from low-bypass ratio engines. This effort concentrated on both analytical and experimental approaches using various mixer designs. CFD and MGB predictions are compared with LDV and noise data, respectively. While former predictions matched well with data, experiment shows a need for improving the latter predictions. Data also show that mixing noise can be sensitive to engine hardware upstream of the mixing exit plane.

  18. Altitude test of several afterburner configurations on a turbofan engine with a hydrogen heater to simulate an elevated turbine discharge temperature

    NASA Technical Reports Server (NTRS)

    Johnsen, R. L.; Cullom, R. R.

    1977-01-01

    A performance test of several experimental afterburner configurations was conducted with a mixed-flow turbofan engine in an altitude facility. The simulated flight conditions were for Mach 1.4 at two altitudes, 12,190 and 14,630 meters. Turbine discharge temperatures of 889 and 1056 K were used. A production afterburner was tested for comparison. The research afterburners included partial forced mixers with V-gutter flameholders, a carburetted V-gutter flameholder, and a triple ring V-gutter flameholder with four swirl-can fuel mixers. Fuel injection variations were included. Performance data shown include augmented thrust ratio, thrust specific fuel consumption, combustion efficiency, and total pressure drop across the afterburner.

  19. Separating Direct and Indirect Turbofan Engine Combustion Noise While Estimating Post-Combustion (Post-Flame) Residence Time Using the Correlation Function

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey Hilton

    2011-01-01

    A previous investigation on the presence of direct and indirect combustion noise for a full-scale turbofan engine using a far-field microphone at 130 is extended by also examining signals obtained at two additional downstream directions using far-field microphones at 110 deg and 160 deg. A generalized cross-correlation function technique is used to study the change in propagation time to the far field of the combined direct and indirect combustion noise signal as a sequence of low-pass filters are applied. The filtering procedure used produces no phase distortion. As the low-pass filter frequency is decreased, the travel time increases because the relative amount of direct combustion noise is reduced. The indirect combustion noise signal travels more slowly because in the combustor entropy fluctuations move with the flow velocity, which is slow compared to the local speed of sound. The indirect combustion noise signal travels at acoustic velocities after reaching the turbine and being converted into an acoustic signal. The direct combustion noise is always propagating at acoustic velocities. The results show that the estimated indirect combustion noise time delay values (post-combustion residence times) measured at each angle are fairly consistent with one another for a relevant range of operating conditions and demonstrate source separation of a mixture of direct and indirect combustion noise. The results may lead to a better idea about the acoustics in the combustor and may help develop and validate improved reduced-order physics-based methods for predicting turbofan engine core noise.

  20. Advanced Natural Gas Reciprocating Engine(s)

    SciTech Connect

    Kwok, Doris; Boucher, Cheryl

    2009-09-30

    Energy independence and fuel savings are hallmarks of the nation’s energy strategy. The advancement of natural gas reciprocating engine power generation technology is critical to the nation’s future. A new engine platform that meets the efficiency, emissions, fuel flexibility, cost and reliability/maintainability targets will enable American manufacturers to have highly competitive products that provide substantial environmental and economic benefits in the US and in international markets. Along with Cummins and Waukesha, Caterpillar participated in a multiyear cooperative agreement with the Department of Energy to create a 50% efficiency natural gas powered reciprocating engine system with a 95% reduction in NOx emissions by the year 2013. This platform developed under this agreement will be a significant contributor to the US energy strategy and will enable gas engine technology to remain a highly competitive choice, meeting customer cost of electricity targets, and regulatory environmental standard. Engine development under the Advanced Reciprocating Engine System (ARES) program was divided into phases, with the ultimate goal being approached in a series of incremental steps. This incremental approach would promote the commercialization of ARES technologies as soon as they emerged from development and would provide a technical and commercial foundation of later-developing technologies. Demonstrations of the Phase I and Phase II technology were completed in 2004 and 2008, respectively. Program tasks in Phase III included component and system development and testing from 2009-2012. Two advanced ignition technology evaluations were investigated under the ARES program: laser ignition and distributed ignition (DIGN). In collaboration with Colorado State University (CSU), a laser ignition system was developed to provide ignition at lean burn and high boost conditions. Much work has been performed in Caterpillar’s DIGN program under the ARES program. This work

  1. Advanced engineering environment pilot project.

    SciTech Connect

    Schwegel, Jill; Pomplun, Alan R.; Abernathy, Rusty

    2006-10-01

    The Advanced Engineering Environment (AEE) is a concurrent engineering concept that enables real-time process tooling design and analysis, collaborative process flow development, automated document creation, and full process traceability throughout a product's life cycle. The AEE will enable NNSA's Design and Production Agencies to collaborate through a singular integrated process. Sandia National Laboratories and Parametric Technology Corporation (PTC) are working together on a prototype AEE pilot project to evaluate PTC's product collaboration tools relative to the needs of the NWC. The primary deliverable for the project is a set of validated criteria for defining a complete commercial off-the-shelf (COTS) solution to deploy the AEE across the NWC.

  2. Advanced System for Process Engineering

    1992-02-01

    ASPEN (Advanced System for Process Engineering) is a state of the art process simulator and economic evaluation package which was designed for use in engineering fossil energy conversion processes. ASPEN can represent multiphase streams including solids, and handle complex substances such as coal. The system can perform steady state material and energy balances, determine equipment size and cost, and carry out preliminary economic evaluations. It is supported by a comprehensive physical property system for computationmore » of major properties such as enthalpy, entropy, free energy, molar volume, equilibrium ratio, fugacity coefficient, viscosity, thermal conductivity, and diffusion coefficient for specified phase conditions; vapor, liquid, or solid. The properties may be computed for pure components, mixtures, or components in a mixture, as appropriate. The ASPEN Input Language is oriented towards process engineers.« less

  3. Advanced fuel chemistry for advanced engines.

    SciTech Connect

    Taatjes, Craig A.; Jusinski, Leonard E.; Zador, Judit; Fernandes, Ravi X.; Miller, James A.

    2009-09-01

    Autoignition chemistry is central to predictive modeling of many advanced engine designs that combine high efficiency and low inherent pollutant emissions. This chemistry, and especially its pressure dependence, is poorly known for fuels derived from heavy petroleum and for biofuels, both of which are becoming increasingly prominent in the nation's fuel stream. We have investigated the pressure dependence of key ignition reactions for a series of molecules representative of non-traditional and alternative fuels. These investigations combined experimental characterization of hydroxyl radical production in well-controlled photolytically initiated oxidation and a hybrid modeling strategy that linked detailed quantum chemistry and computational kinetics of critical reactions with rate-equation models of the global chemical system. Comprehensive mechanisms for autoignition generally ignore the pressure dependence of branching fractions in the important alkyl + O{sub 2} reaction systems; however we have demonstrated that pressure-dependent 'formally direct' pathways persist at in-cylinder pressures.

  4. Advanced engineering environment collaboration project.

    SciTech Connect

    Lamph, Jane Ann; Pomplun, Alan R.; Kiba, Grant W.; Dutra, Edward G.; Dankiewicz, Robert J.; Marburger, Scot J.

    2008-12-01

    The Advanced Engineering Environment (AEE) is a model for an engineering design and communications system that will enhance project collaboration throughout the nuclear weapons complex (NWC). Sandia National Laboratories and Parametric Technology Corporation (PTC) worked together on a prototype project to evaluate the suitability of a portion of PTC's Windchill 9.0 suite of data management, design and collaboration tools as the basis for an AEE. The AEE project team implemented Windchill 9.0 development servers in both classified and unclassified domains and used them to test and evaluate the Windchill tool suite relative to the needs of the NWC using weapons project use cases. A primary deliverable was the development of a new real time collaborative desktop design and engineering process using PDMLink (data management tool), Pro/Engineer (mechanical computer aided design tool) and ProductView Lite (visualization tool). Additional project activities included evaluations of PTC's electrical computer aided design, visualization, and engineering calculations applications. This report documents the AEE project work to share information and lessons learned with other NWC sites. It also provides PTC with recommendations for improving their products for NWC applications.

  5. The Cummins advanced turbocompound diesel engine evaluation

    NASA Technical Reports Server (NTRS)

    Hoehne, J. L.; Werner, J. R.

    1982-01-01

    An advanced turbocompound diesel engine program was initiated to improve the tank mileage of the turbocompound engine by 5% over the vehicle test engines. Engine improvements could be realized by increasing the available energy of the exhaust gas at the turbine inlet, incorporating gas turbine techniques into improving the turbomachinery efficiencies, and through refined engine system optimization. The individual and cumulative performance gains achieved with the advanced turbocompound engine improvements are presented.

  6. Advanced Prop-fan Engine Technology (APET) single- and counter-rotation gearbox/pitch change mechanism

    NASA Technical Reports Server (NTRS)

    Reynolds, C. N.

    1985-01-01

    The preliminary design of advanced technology (1992) prop-fan engines for single-rotation prop-fans, the conceptual design of the entire propulsion system, and an aircraft evaluation of the resultant designs are discussed. Four engine configurations were examined. A two-spool engine with all axial compressors and a three-spool engine with axial/centrifugal compressors were selected. Integrated propulsion systems were designed in conjunction with airframe manufacturers. The design efforts resulted in 12,000 shaft horsepower engines installed in over the installations with in-line and offset gearboxes. The prop-fan powered aircraft used 21 percent less fuel and cost 10 percent less to operate than a similar aircraft powered by turbofan engines with comparable technology.

  7. Acoustic, performance, and wake survey measurements of a lobed velocity-decayer nozzle installed on a quieted TF-34 turbofan engine

    NASA Technical Reports Server (NTRS)

    Samanich, N. E.; Heidelberg, L. J.

    1976-01-01

    Results for three velocity decayer nozzle configurations are compared with those obtained with a separate flow coannular nozzle tested on the same quieted turbofan engine. Peak sideline noise, which occurred 110 degrees from the inlet, was 2 to 4 db louder than with the coannular nozzle at the same ideal effective exhaust velocity and 8 to 11 db louder at the same thrust level. The decayer nozzles produced an increase in loss equivalent to about 4 percent of the engine thrust and also increased the effective exhaust velocity of the engine. The exhaust decayed to 0.35 of its peak velocity, compared with no decay for the coannular nozzle, within 3 equivalent nozzle diameters of the exit. The peak exhaust gas temperature was 400 K lower for the decayer configuration at the same location. The increase in perceived noise level for the decayer nozzles as compared with the coannular nozzle was attributed to the increase in exhaust velocity and the shift in peak spectrum frequency produced by these nozzles.

  8. Turbofan engine with a low pressure turbine driven supercharger in a bypass duct operated by a fuel rich combustor and an afterburner

    NASA Technical Reports Server (NTRS)

    Bartos, James W. (Inventor)

    1999-01-01

    A multiple bypass turbofan engine includes a core Brayton Cycle gas generator with a fuel rich burning combustor and is provided with a variable supercharged bypass duct around the gas generator with a supercharging means in the supercharged bypass duct powered by a turbine not mechanically connected to the gas generator. The engine further includes a low pressure turbine driven forward fan upstream and forward of an aft fan and drivingly connected to a low pressure turbine by a low pressure shaft, the low pressure turbine being aft of and in serial flow communication with the core gas generator. A fan bypass duct is disposed radially outward of the core engine assembly and has first and second inlets disposed between the forward and aft fans. An inlet duct having an annular duct wall is disposed radially inward of the bypass duct and connects the second inlet to the bypass duct. A supercharger means for compressing air is drivingly connected to the low pressure turbine and is disposed in the inlet duct. A secondary combustor or augmentor is disposed in an exhaust duct downstream of and in fluid flow communication with the bypass duct and the gas generator.

  9. Finite element-integral simulation of static and flight fan noise radiation from the JT15D turbofan engine

    NASA Astrophysics Data System (ADS)

    Baumeister, K. J.; Horowitz, S. J.

    An iterative finite element integral technique is used to predict the sound field radiated from the JT15D turbofan inlet. The sound field is divided into two regions: the sound field within and near the inlet which is computed using the finite element method and the radiation field beyond the inlet which is calculated using an integral solution technique. The velocity potential formulation of the acoustic wave equation was employed in the program. For some single mode JT15D data, the theory and experiment are in good agreement for the far field radiation pattern as well as suppressor attenuation. Also, the computer program is used to simulate flight effects that cannot be performed on a ground static test stand.

  10. Phase 2 program on ground test of refanned JT8D turbofan engines and nacelles for the 727 airplane. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The propulsion performance, acoustic, structural, and systems changes to a 727-200 airplane retrofitted with a refan modification of the JT8D turbofan engine are evaluated. Model tests, design of certifiable airplane retrofit kit hardware, manufacture of test hardware, ground test of a current production JT8D engine, followed by test of the same engine modified to the refan configuration, detailed analyses of the retrofit impact on airplane airworthiness, performance, and noise, and a preliminary analysis of retrofit costs are included. Results indicate that the refan retrofit of the 727-200 would be certifiable and would result in a 6-to 8 EPNdb reduction in effective perceived noise level (EPNL) at the FAR 36 measuring points and an annoyance-weighted footprint area reduction of 68% to 83%. The installed refan engine is estimated to provide 14% greater takeoff thrust at zero velocity and 10% greater thrust at 100 kn (51.4 m/s). There would be an approximate 0.6% increase in cruise specific fuel consumption (SFC). The refan engine performance in conjunction with the increase in stalled weight results in a range reduction of approximately 15% over the unmodified airplane at the same brake release gross weight (BRGW), with a block fuel increase of 1.5% to 3%. With the particular model 727 that was studied, however, it is possible to operate the airplane (with minor structural modifications) at a higher BRGW and increase the range up to approximately 15% relative to the nonrefanned airplane (with equal or slightly increased noise levels). The JT8D refan engine also improves the limited-field range of the airplane.

  11. Small Engine Component Technology (SECT) studies

    NASA Technical Reports Server (NTRS)

    Meyer, P. K.; Harbour, L.

    1986-01-01

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

  12. Static test-stand performance of the YF-102 turbofan engine with several exhaust configurations for the Quiet Short-Haul Research Aircraft (QSRA)

    NASA Technical Reports Server (NTRS)

    Mcardle, J. G.; Homyak, L.; Moore, A. S.

    1979-01-01

    The performance of a YF-102 turbofan engine was measured in an outdoor test stand with a bellmouth inlet and seven exhaust-system configurations. The configurations consisted of three separate-flow systems of various fan and core nozzle sizes and four confluent-flow systems of various nozzle sizes and shapes. A computer program provided good estimates of the engine performance and of thrust at maximum rating for each exhaust configuration. The internal performance of two different-shaped core nozzles for confluent-flow configurations was determined to be satisfactory. Pressure and temperature surveys were made with a traversing probe in the exhaust-nozzle flow for some confluent-flow configurations. The survey data at the mixing plane, plus the measured flow rates, were used to calculate the static-pressure variation along the exhaust nozzle length. The computed pressures compared well with experimental wall static-pressure data. External-flow surveys were made, for some confluent-flow configurations, with a large fixed rake at various locations in the exhaust plume.

  13. Advanced System for Process Engineering

    1998-09-14

    PRO ASPEN/PC1.0 (Advanced System for Process Engineering) is a state of the art process simulator and economic evaluation package which was designed for use in engineering fossil energy conversion processes and has been ported to run on a PC. PRO ASPEN/PC1.0 can represent multiphase streams including solids, and handle complex substances such as coal. The system can perform steady state material and energy balances, determine equipment size and cost, and carry out preliminary economic evaluations.more » It is supported by a comprehensive physical property system for computation of major properties such as enthalpy, entropy, free energy, molar volume, equilibrium ratio, fugacity coefficient, viscosity, thermal conductivity, and diffusion coefficient for specified phase conditions; vapor, liquid, or solid. The properties may be computed for pure components, mixtures, or components in a mixture, as appropriate. The PRO ASPEN/PC1.0 Input Language is oriented towards process engineers.« less

  14. 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.

  15. Genetically Engineered Immunotherapy for Advanced Cancer

    Cancer.gov

    In this trial, doctors will collect T lymphocytes from patients with advanced mesothelin-expressing cancer and genetically engineer them to recognize mesothelin. The gene-engineered cells will be multiplied and infused into the patient to fight the cancer

  16. New engine and advanced component design

    SciTech Connect

    Not Available

    1990-01-01

    This book contains the proceedings on new engine and advance component design. Topics covered include: development of low emission high performance four valve engines, the effect of engine build options on powerplant inertias, silicon nitride turbocharger rotor for high performance automotive engines and development of Toyota reflex Burn (TRB) system in DI diesel.

  17. Programmed electronic advance for engines

    SciTech Connect

    Dogadko, P.

    1987-03-03

    An ignition advance control is described for an internal combustion engine including a crankshaft, a throttle control, and at least one cylinder, the ignition advance control comprising a spark ignition circuit associated with the cylinder and including trigger means operative to cause an ignition spark, means for generating a control pulse associated with the cylinder, latch means for enabling the trigger means in response to generation of the control pulse, means for generating a constant plurality of sequentially occurring electrical reference pulses during each revolution of the crankshaft, means for counting the reference pulses developed during each revolution of the crankshaft, means for firing the enabled trigger means in response to the counting means counting a predetermined number of the reference pulses to cause the ignition spark at a predetermined ignition point in each revolution of the crankshaft, means for sensing the position of the throttle control, and means responsive to the throttle sensing means for varying the predetermined number of reference pulses solely in accordance with the position of the throttle control to vary the predetermined ignition point as appropriate for the position of the throttle control.

  18. Ice Particle Transport Analysis With Phase Change for the E(sup 3) Turbofan Engine Using LEWICE3D Version 3.2

    NASA Technical Reports Server (NTRS)

    Bidwell, Colin, S.

    2012-01-01

    Ice Particle trajectory calculations with phase change were made for the Energy Efficient Engine (E(sup 3)) using the LEWICE3D Version 3.2 software. The particle trajectory computations were performed using the new Glenn Ice Particle Phase Change Model which has been incorporated into the LEWICE3D Version 3.2 software. The E(sup 3) was developed by NASA and GE in the early 1980 s as a technology demonstrator and is representative of a modern high bypass turbofan engine. The E(sup 3) flow field was calculated using the NASA Glenn ADPAC turbomachinery flow solver. Computations were performed for the low pressure compressor of the E(sup 3) for a Mach 0.8 cruise condition at 11,887 m assuming a standard warm day for ice particle sizes of 5, 20, and 100 microns and a free stream particle concentration of 0.3 g/cu m. The impingement efficiency results showed that as particle size increased average impingement efficiencies and scoop factors increased for the various components. The particle analysis also showed that the amount of mass entering the inner core decreased with increased particle size because the larger particles were less able to negotiate the turn into the inner core due to particle inertia. The particle phase change analysis results showed that the larger particles warmed less as they were transported through the low pressure compressor. Only the smallest 5 micron particles were warmed enough to produce melting and the amount of melting was relatively small with a maximum average melting fraction of 0.836. The results also showed an appreciable amount of particle sublimation and evaporation for the 5 micron particles entering the engine core (22 percent).

  19. 76 FR 59013 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 800 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-23

    ... . SUPPLEMENTARY INFORMATION: Airworthiness Directive 2011-08-07, Amendment 39-16657 (76 FR 24798, May 3, 2011..., Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England..., Massachusetts on September 9, 2011. Peter A. White, Manager, Engine & Propeller Directorate,...

  20. 75 FR 51657 - Airworthiness Directives; Pratt & Whitney Canada Corp. (P&WC) PW615F-A Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ... could result in an unsafe condition. The PW615F-A engine Fuel Filter Bypass Valve installation is very... uncommanded power reduction on one of its engines. Investigation showed that the Fuel Filter Bypass Valve... condition. The PW615F-A engine Fuel Filter Bypass Valve installation is very similar to that of...

  1. 75 FR 17630 - Airworthiness Directives; Rolls-Royce plc RB211 Trent 700 and Trent 800 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-07

    ... Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park... Register published on April 11, 2000 (65 FR 19477-78). Discussion The European Aviation Safety Agency (EASA... life of the shaft to below the published life limits. The acceptable limits for material loss on...

  2. 76 FR 64293 - Airworthiness Directives; CFM International, S. A. Model CFM56-5B Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-18

    ... Phone: 33 1 64 14 88 66; Fax: 33 1 64 79 85 55; e-mail: snecma.csc@snecma.fr . ] Examining the AD Docket... Fernandes, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New... 12866, (2) Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR...

  3. Comparison of calculated and altitude-facility-measured thrust and airflow of two prototype F100 turbofan engines

    NASA Technical Reports Server (NTRS)

    Kurtenbach, F. J.

    1978-01-01

    A comparison is made of the facility performance data for the two engines with an engine performance model, and it provides corrections that can be applied to the model so that it represents the test engines accurately over the flight envelope. Test conditions ranged from Mach numbers of 0.80 to 2.00 and altitudes from 4020 meters to 15,240 meters. Two distortion screens were used to determine the effect of distortion on airflow. Reynolds number effects were also determined. Engine hysteresis is documented, as is an attempt to determine engine degradation. The calibrated engine model had a twice standard deviation accuracy of approximately 1.24 percent for corrected airflow and 2.38 percent for gross thrust.

  4. Active control of low-speed turbofan tonal noise

    NASA Astrophysics Data System (ADS)

    Sommerfeldt, Scott D.; Remington, Paul J.

    2003-10-01

    Active noise control has been proposed as a technique for reducing the tonal noise radiated from turbofan engines. The sound field in the duct of a turbofan engine is characterized by acoustic modes, which exhibit both a radial and a circumferential spatial dependence. The dominant circumferential modes are determined by the relationship between the number of rotor and stator blades. Using these concepts, an active noise control system has been developed to measure and minimize the modes in the duct of a turbofan engine. By using multiple source and sensor locations, it has also been shown that it is possible to control multiple radial modes within the engine duct. Some of the issues associated with the design of the control system will be reviewed, and results obtained using the Active Noise Control Fan (ANCF) at NASA Glenn Research Center will be presented. [Work supported by NASA.

  5. Engineering visualization utilizing advanced animation

    NASA Technical Reports Server (NTRS)

    Sabionski, Gunter R.; Robinson, Thomas L., Jr.

    1989-01-01

    Engineering visualization is the use of computer graphics to depict engineering analysis and simulation in visual form from project planning through documentation. Graphics displays let engineers see data represented dynamically which permits the quick evaluation of results. The current state of graphics hardware and software generally allows the creation of two types of 3D graphics. The use of animated video as an engineering visualization tool is presented. The engineering, animation, and videography aspects of animated video production are each discussed. Specific issues include the integration of staffing expertise, hardware, software, and the various production processes. A detailed explanation of the animation process reveals the capabilities of this unique engineering visualization method. Automation of animation and video production processes are covered and future directions are proposed.

  6. 75 FR 14377 - Airworthiness Directives; Pratt & Whitney (PW) Model PW2037, PW2037(M), and PW2040 Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-25

    ... from PW2000 engine health monitoring data. The FTDM condition can result in an inability of the engine... Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78). Examining the AD Docket You... Procedures (44 FR 11034, February 26, 1979); and 3. Would not have a significant economic impact, positive...

  7. 75 FR 49368 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 900 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ..., Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park... complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78...'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will not...

  8. 76 FR 12277 - Airworthiness Directives; Rolls-Royce plc RB211-Trent 768, 772, and 772B Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-07

    ...: ] Discussion On April 23, 1998, the FAA Engine & Propeller Directorate issued engine AD 98-09-27 (63 FR 24911... (66 FR 23838, May 10, 2001). Those ADs both require the same initial and repetitive visual inspections... published in the Federal Register on November 15, 2010 (75 FR 69611), and proposed to rescind AD...

  9. Ceramic Technology for Advanced Heat Engines Project

    SciTech Connect

    Not Available

    1990-08-01

    The Ceramic Technology For Advanced Heat Engines Project was developed by the Department of Energy's Office of Transportation Systems (OTS) in Conservation and Renewable Energy. This project, part of the OTS's Advanced Materials Development Program, was developed to meet the ceramic technology requirements of the OTS's automotive technology programs. Significant accomplishments in fabricating ceramic components for the Department of Energy (DOE), National Aeronautics and Space Administration (NASA), and Department of Defense (DOD) advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. An assessment of needs was completed, and a five year project plan was developed with extensive input from private industry. The objective of the project is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on structural ceramics for advanced gas turbine and diesel engines, ceramic hearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines.

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

    NASA Technical Reports Server (NTRS)

    Sargisson, D. F.

    1985-01-01

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

  11. Advances in engineering science, volume 1

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Proceedings from a conference on engineering advances are presented, including materials science, fracture mechanics, and impact and vibration testing. The tensile strength and moisture transport of laminates are also discussed.

  12. 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.

  13. Advanced materials for aircraft engine applications.

    PubMed

    Backman, D G; Williams, J C

    1992-02-28

    A review of advances for aircraft engine structural materials and processes is presented. Improved materials, such as superalloys, and the processes for making turbine disks and blades have had a major impact on the capability of modern gas turbine engines. New structural materials, notably composites and intermetallic materials, are emerging that will eventually further enhance engine performance, reduce engine weight, and thereby enable new aircraft systems. In the future, successful aerospace manufacturers will combine product design and materials excellence with improved manufacturing methods to increase production efficiency, enhance product quality, and decrease the engine development cycle time.

  14. Advanced materials for aircraft engine applications.

    PubMed

    Backman, D G; Williams, J C

    1992-02-28

    A review of advances for aircraft engine structural materials and processes is presented. Improved materials, such as superalloys, and the processes for making turbine disks and blades have had a major impact on the capability of modern gas turbine engines. New structural materials, notably composites and intermetallic materials, are emerging that will eventually further enhance engine performance, reduce engine weight, and thereby enable new aircraft systems. In the future, successful aerospace manufacturers will combine product design and materials excellence with improved manufacturing methods to increase production efficiency, enhance product quality, and decrease the engine development cycle time. PMID:17817782

  15. Modeling the Effects of Ice Accretion on the Low Pressure Compressor and the Overall Turbofan Engine System Performance

    NASA Technical Reports Server (NTRS)

    Veres, Joseph P.; Jorgenson, Philip C. E.; Wright, William B.

    2011-01-01

    The focus of this study is on utilizing a mean line compressor flow analysis code coupled to an engine system thermodynamic code, to estimate the effects of ice accretion on the low pressure compressor, and quantifying its effects on the engine system throughout a notional flight trajectory. In this paper a temperature range in which engine icing would occur was assumed. This provided a mechanism to locate potential component icing sites and allow the computational tools to add blockages due to ice accretion in a parametric fashion. Ultimately the location and level of blockage due to icing would be provided by an ice accretion code. To proceed, an engine system modeling code and a mean line compressor flow analysis code were utilized to calculate the flow conditions in the fan-core and low pressure compressor and to identify potential locations within the compressor where ice may accrete. In this study, an "additional blockage" due to the accretion of ice on the metal surfaces, has been added to the baseline aerodynamic blockage due to boundary layer, as well as the blade metal blockage. Once the potential locations of ice accretion are identified, the levels of additional blockage due to accretion were parametrically varied to estimate the effects on the low pressure compressor blade row performance operating within the engine system environment. This study includes detailed analysis of compressor and engine performance during cruise and descent operating conditions at several altitudes within the notional flight trajectory. The purpose of this effort is to develop the computer codes to provide a predictive capability to forecast the onset of engine icing events, such that they could ultimately help in the avoidance of these events.

  16. Advanced space engine preliminary design

    NASA Technical Reports Server (NTRS)

    Cuffe, J. P. B.; Bradie, R. E.

    1973-01-01

    A preliminary design was completed for an O2/H2, 89 kN (20,000 lb) thrust staged combustion rocket engine that has a single-bell nozzle with an overall expansion ratio of 400:1. The engine has a best estimate vacuum specific impulse of 4623.8 N-s/kg (471.5 sec) at full thrust and mixture ratio = 6.0. The engine employs gear-driven, low pressure pumps to provide low NPSH capability while individual turbine-driven, high-speed main pumps provide the system pressures required for high-chamber pressure operation. The engine design dry weight for the fixed-nozzle configuration is 206.9 kg (456.3 lb). Engine overall length is 234 cm (92.1 in.). The extendible nozzle version has a stowed length of 141.5 cm (55.7 in.). Critical technology items in the development of the engine were defined. Development program plans and their costs for development, production, operation, and flight support of the ASE were established for minimum cost and minimum time programs.

  17. Engine health monitoring: An advanced system

    NASA Technical Reports Server (NTRS)

    Dyson, R. J. E.

    1981-01-01

    The advanced propulsion monitoring system is described. The system was developed in order to fulfill a growing need for effective engine health monitoring. This need is generated by military requirements for increased performance and efficiency in more complex propulsion systems, while maintaining or improving the cost to operate. This program represents a vital technological step in the advancement of the state of the art for monitoring systems in terms of reliability, flexibility, accuracy, and provision of user oriented results. It draws heavily on the technology and control theory developed for modern, complex, electronically controlled engines and utilizes engine information which is a by-product of such a system.

  18. Noise-Source Separation Using Internal and Far-Field Sensors for a Full-Scale Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.; Miles, Jeffrey H.

    2009-01-01

    Noise-source separation techniques for the extraction of the sub-dominant combustion noise from the total noise signatures obtained in static-engine tests are described. Three methods are applied to data from a static, full-scale engine test. Both 1/3-octave and narrow-band results are discussed. The results are used to assess the combustion-noise prediction capability of the Aircraft Noise Prediction Program (ANOPP). A new additional phase-angle-based discriminator for the three-signal method is also introduced.

  19. 77 FR 10355 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 800 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-22

    ....aeromanager.com . You may review copies of the referenced service information at the FAA, Engine & Propeller... material at the FAA, call 781- 238-7125. Examining the AD Docket You may examine the AD docket on the... & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7143; fax:...

  20. Rotating Rake Turbofan Duct Mode Measurement System

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.

    2005-01-01

    An experimental measurement system was developed and implemented by the NASA Glenn Research Center in the 1990s to measure turbofan duct acoustic modes. The system is a continuously rotating radial microphone rake that is inserted into the duct. This Rotating Rake provides a complete map of the acoustic duct modes present in a ducted fan and has been used on a variety of test articles: from a low-speed, concept test rig, to a full-scale production turbofan engine. The Rotating Rake has been critical in developing and evaluating a number of noise reduction concepts as well as providing experimental databases for verification of several aero-acoustic codes. More detailed derivation of the unique Rotating Rake equations are presented in the appendix.

  1. Quiet Clean General Aviation Turbofan (QCGAT) technology study, volume 1

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The preliminary design of an engine which satisfies the requirements of a quiet, clean, general aviation turbofan (QCGAT) engine is described. Also an experimental program to demonstrate performance is suggested. The T700 QCGAT engine preliminary design indicates that it will radiate noise at the same level as an aircraft without engine noise, have exhaust emissions within the EPA 1981 Standards, have lower fuel consumption than is available in comparable size engines, and have sufficient life for five years between overhauls.

  2. Evaluation of a simplified gross thrust calculation technique using two prototype F100 turbofan engines in an altitude facility

    NASA Technical Reports Server (NTRS)

    Kurtenbach, F. J.

    1979-01-01

    The technique which relies on afterburner duct pressure measurements and empirical corrections to an ideal one dimensional flow analysis to determine thrust is presented. A comparison of the calculated and facility measured thrust values is reported. The simplified model with the engine manufacturer's gas generator model are compared. The evaluation was conducted over a range of Mach numbers from 0.80 to 2.00 and at altitudes from 4020 meters to 15,240 meters. The effects of variations in inlet total temperature from standard day conditions were explored. Engine conditions were varied from those normally scheduled for flight. The technique was found to be accurate to a twice standard deviation of 2.89 percent, with accuracy a strong function of afterburner duct pressure difference.

  3. Flight evaluation of a simplified gross thrust calculation technique using an F100 turbofan engine in an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Kurtenbach, F. J.; Burcham, F. W., Jr.

    1981-01-01

    A simplified gross thrust calculation technique was evaluated in flight tests on an F-15 aircraft using prototype F100-PW-100 engines. The technique relies on afterburner duct pressure measurements and empirical corrections to an ideal one-dimensional analysis to determine thrust. In-flight gross thrust calculated by the simplified method is compared to gross thrust calculated by the engine manufacturer's gas generator model. The evaluation was conducted at Mach numbers from 0.6 to 1.5 and at altitudes from 6000 meters to 13,700 meters. The flight evaluation shows that the simplified gross thrust method and the gas generator method agreed within plus or minus 3 percent. The discrepancies between the data generally fell within an uncertainty band derived from instrumentation errors and recording system resolution.

  4. Advanced subsonic transport propulsion

    NASA Technical Reports Server (NTRS)

    Nored, D. L.; Ciepluch, C. C.; Chamberlain, R.; Meleason, E. T.; Kraft, G. A.

    1981-01-01

    A brief review of the current NASA Energy Efficient Engine (E(3)) Project is presented. Included in this review are the factors that influenced the design of these turbofan engines and the advanced technology incorporated in them to reduce fuel consumption and improve environmental characteristics. In addition, factors such as the continuing spiral in fuel cost, that could influence future aircraft propulsion systems beyond those represented by the E(3) engines, are also discussed. Advanced technologies that will address these influencing factors and provide viable future propulsion systems are described. The potential importance of other propulsion system types, such as geared fans and turboshaft engines, is presented.

  5. Advances in meniscal tissue engineering.

    PubMed

    Eli, Nnaemeka; Oragui, Emeka; Khan, Wasim

    2011-01-01

    Injuries and lesions to the meniscal cartilage of the knee joint are common. As a result of its limited regenerative capacity, early degenerative changes to the articular surface frequently occur, resulting in pain and poor function. Currently available surgical interventions include repair of tears, and partial and total meniscectomy but the results are inconsistent and often poor. Interest in the field of meniscal tissue engineering with the possibilities of better treatment outcomes has grown in recent times. Current research has focused on the use of mesenchymal stem cells, fibrochondrocytes, meniscal derived cells and fibroblast-like synoviocytes in tissue engineering. Mesenchymal stem cells are multipotent cells that have been identified in a number of tissues including bone marrow and synovium. Current research is aimed at defining the correct combination of cytokines and growth factors necessary to induce specific tissue formation and includes transforming growth factor-β (TGF-β), Platelet Derived Growth Factor (PDGF) and Fibroblast Growth Factor 2 (FGF2). Scaffolds provide mechanical stability and integrity, and supply a template for three-dimensional organization of the developing tissue. A number of experimental and animal models have been used to investigate the ideal scaffolds for meniscal tissue engineering. The ideal scaffold for meniscal tissue engineering has not been identified but biodegradable scaffolds have shown the most promising results. In addition to poly-glycolic acid (PGA) and poly-lactic acid (PLLA) scaffolds, new synthetic hydrogels and collagen sponges are also being explored. There are two synthetic meniscal implants currently in clinical use and there are a number of clinical trials in the literature with good short- and medium-term results. Both products are indicated for segmental tissue loss and not for complete meniscal replacement. The long-term results of these implants are unknown and we wait to see whether they will be

  6. Altitude performance of a low-noise-technology fan in a turbofan engine with and without a sound suppressing nacelle

    NASA Technical Reports Server (NTRS)

    Biesiadny, T. J.; Grey, R. E.; Abdelwahah, M.

    1976-01-01

    Test variables were inlet Reynolds number index (0.2 to 0.5), flight Mach number (0.2 to 0.8), and flow distortion (tip radial and combined circumferential - tip radial patterns). Results are limited to fan bypass and overall engine performance. There were no discernible effects of Reynolds number on fan performance. Increasing flight Mach number shifted the fan operating line such that pressure ratio decreased and airflow increased. Inlet flow distortion lowered stall margin. For a Reynolds number index of 0.2 and flight Mach number of 0.54, the sound suppressing nacelle lowered fan efficiency three points and increased specific fuel consumption about 10 percent.

  7. Turbofan Noise Reduction Associated With Increased Bypass Nozzle Flow

    NASA Technical Reports Server (NTRS)

    Woodward, Richard P.; Hughes, Christopher E.

    2005-01-01

    An advanced 22-in. scale model turbofan, typical of a current-generation aircraft engine design by GE Aircraft Engines, was tested in NASA Glenn Research Center s 9- by 15- Foot Low-Speed Wind Tunnel to explore the far-field acoustic effects of an increased bypass nozzle area at simulated aircraft speeds of takeoff, approach, and landing. The wind-tunnel-scale model consisted of the bypass stage fan, stators, and nacelle (including the fan exit nozzle) of a typical turbofan. This fan-stage test was part of the NASA Glenn Fan Broadband Source Diagnostic Test, second entry, which acquired aeroacoustic results over a range of test conditions. A baseline nozzle was selected, and the nozzle area was chosen for maximum performance at sea-level conditions. Two additional nozzles were also tested--one with a 5.4-percent increase in nozzle area over the baseline nozzle (sized for design point conditions), corresponding to a 5-percent increase in fan weight flow, and another nozzle with a 10.9-percent increase in nozzle area over the baseline nozzle (sized for maximum weight flow at sea-level conditions), corresponding to a 7.5 percent increase in fan weight flow. Measured acoustic benefits with increased nozzle area were very encouraging, showing overall sound power level reductions of 2 dB or more (left graph) while the stage adiabatic efficiency (right graph) and thrust (final graph) actually increased by several percentage points. These noise-reduction benefits were seen to include both rotor-interaction tones and broadband noise, and were evident throughout the range of measured sideline angles.

  8. New perspectives for advanced automobile diesel engines

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  9. Effects of mistuning on bending-torsion flutter and response of a cascade in incompressible flow. [turbofan engines

    NASA Technical Reports Server (NTRS)

    Kaza, K. R. V.; Kielb, R. E.

    1981-01-01

    The effect of small differences between the individual blades (mistuning) on the aeroelastic stability and response of a cascade were studied. The aerodynamic, inertial, and structural coupling between the bending and torsional motions of each blade and the aerodynamic coupling between the blades was considered. A digital computer program was developed to conduct parametric studies. Results indicate that the mistuning has a beneficial effect on the coupled bending torsion and uncoupled torsion flutter. On forced response, however, the effect may be either beneficial or adverse, depending on the engine order of the forcing function. The results also illustrate that it may be feasible to utilize mistuning as a passive control to increase flutter speed while maintaining forced response at an acceptable level.

  10. Advancements in engineering turbulence modeling

    NASA Technical Reports Server (NTRS)

    Shih, T.-H.

    1991-01-01

    Some new developments in two-equation models and second order closure models are presented. Two-equation models (k-epsilon models) have been widely used in computational fluid dynamics (CFD) for engineering problems. Most of low-Reynolds number two-equation models contain some wall-distance damping functions to account for the effect of wall on turbulence. However, this often causes the confusion and difficulties in computing flows with complex geometry and also needs an ad hoc treatment near the separation and reattachment points. A set of modified two-equation models is proposed to remove the aforementioned shortcomings. The calculations using various two-equation models are compared with direct numerical simulations of channel flow and flat boundary layers. Development of a second order closure model is also discussed with emphasis on the modeling of pressure related correlation terms and dissipation rates in the second moment equations. All the existing models poorly predict the normal stresses near the wall and fail to predict the 3-D effect of mean flow on the turbulence (e.g. decrease in the shear stress caused by the cross flow in the boundary layer). The newly developed second order near-wall turbulence model is described and is capable of capturing the near-wall behavior of turbulence as well as the effect of 3-D mean flow on the turbulence.

  11. Advanced oxygen-hydrocarbon rocket engine study

    NASA Technical Reports Server (NTRS)

    Obrien, C. J.

    1980-01-01

    Preliminary identification and evaluation of promising liquid oxygen/ hydrocarbon (LO2/HC) rocket engine cycles is reported. A consistent and reliable data base for vehicle optimization and design studies, to demonstrate the significance of propulsion system improvements, and to select the critical technology areas necessary to realize such advances is presented.

  12. Advanced nozzle and engine components test facility

    NASA Technical Reports Server (NTRS)

    Beltran, Luis R.; Delroso, Richard L.; Delrosario, Ruben

    1992-01-01

    A test facility for conducting scaled advanced nozzle and engine component research is described. The CE-22 test facility, located in the Engine Research Building of the NASA Lewis Research Center, contains many systems for the economical testing of advanced scale-model nozzles and engine components. The combustion air and altitude exhaust systems are described. Combustion air can be supplied to a model up to 40 psig for primary air flow, and 40, 125, and 450 psig for secondary air flow. Altitude exhaust can be simulated up to 48,000 ft, or the exhaust can be atmospheric. Descriptions of the multiaxis thrust stand, a color schlieren flow visualization system used for qualitative flow analysis, a labyrinth flow measurement system, a data acquisition system, and auxiliary systems are discussed. Model recommended design information and temperature and pressure instrumentation recommendations are included.

  13. Design and verification of a turbofan swirl augmentor

    NASA Technical Reports Server (NTRS)

    Egan, W. J., Jr.; Shadowen, J. H.

    1978-01-01

    The paper discusses the details of the design and verification testing of a full-scale turbofan 'swirl' augmentor at sea level and altitude. No flameholders are required in the swirl augmentor since the radial motion of the hot pilot gases and subsequent combustion products provides a continuous ignition front across the stream. Results of rig testing of this full-scale swirl augmentor on an F100 engine, which are very encouraging, and future development plans are presented. The results validate the application of the centrifugal-force swirling flow concept to a turbofan augmentor.

  14. Ceramic technology for Advanced Heat Engines Project

    SciTech Connect

    Johnson, D.R.

    1991-07-01

    Significant accomplishments in fabricating ceramic components for advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and database and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. An assessment of needs was completed, and a five year project plan was developed with extensive input from private industry. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. To facilitate the rapid transfer of this technology to US industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities. This project is managed by ORNL for the Office of Transportation Technologies, Office of Transportation Materials, and is closely coordinated with complementary ceramics tasks funded by other DOE offices, NASA, DOD, and industry.

  15. Advances in protease engineering for laundry detergents.

    PubMed

    Vojcic, Ljubica; Pitzler, Christian; Körfer, Georgette; Jakob, Felix; Ronny Martinez; Maurer, Karl-Heinz; Schwaneberg, Ulrich

    2015-12-25

    Proteases are essential ingredients in modern laundry detergents. Over the past 30 years, subtilisin proteases employed in the laundry detergent industry have been engineered by directed evolution and rational design to tailor their properties towards industrial demands. This comprehensive review discusses recent success stories in subtilisin protease engineering. Advances in protease engineering for laundry detergents comprise simultaneous improvement of thermal resistance and activity at low temperatures, a rational strategy to modulate pH profiles, and a general hypothesis for how to increase promiscuous activity towards the production of peroxycarboxylic acids as mild bleaching agents. The three protease engineering campaigns presented provide in-depth analysis of protease properties and have identified principles that can be applied to improve or generate enzyme variants for industrial applications beyond laundry detergents.

  16. Advanced automotive diesel engine system study

    NASA Technical Reports Server (NTRS)

    1983-01-01

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

  17. Advanced nuclear rocket engine mission analysis

    SciTech Connect

    Ramsthaler, J.; Farbman, G.; Sulmeisters, T.; Buden, D.; Harris, P.

    1987-12-01

    The use of a derivative of the NERVA engine developed from 1955 to 1973 was evluated for potential application to Air Force orbital transfer and maneuvering missions in the time period 1995 to 2020. The NERVA stge was found to have lower life cycle costs (LCC) than an advanced chemical stage for performing low earth orbit (LEO) to geosynchronous orbit (GEO0 missions at any level of activity greater than three missions per year. It had lower life cycle costs than a high performance nuclear electric engine at any level of LEO to GEO mission activity. An examination of all unmanned orbital transfer and maneuvering missions from the Space Transportation Architecture study (STAS 111-3) indicated a LCC advantage for the NERVA stage over the advanced chemical stage of fifteen million dollars. The cost advanced accured from both the orbital transfer and maneuvering missions. Parametric analyses showed that the specific impulse of the NERVA stage and the cost of delivering material to low earth orbit were the most significant factors in the LCC advantage over the chemical stage. Lower development costs and a higher thrust gave the NERVA engine an LCC advantage over the nuclear electric stage. An examination of technical data from the Rover/NERVA program indicated that development of the NERVA stage has a low technical risk, and the potential for high reliability and safe operation. The data indicated the NERVA engine had a great flexibility which would permit a single stage to perform all Air Force missions.

  18. Advanced Engineering Environments: Implications for Aerospace Manufacturing

    NASA Technical Reports Server (NTRS)

    Thomas, D.

    2001-01-01

    There are significant challenges facing today's aerospace industry. Global competition, more complex products, geographically-distributed design teams, demands for lower cost, higher reliability and safer vehicles, and the need to incorporate the latest technologies quicker all face the developer of aerospace systems. New information technologies offer promising opportunities to develop advanced engineering environments (AEEs) to meet these challenges. Significant advances in the state-of-the-art of aerospace engineering practice are envisioned in the areas of engineering design and analytical tools, cost and risk tools, collaborative engineering, and high-fidelity simulations early in the development cycle. These advances will enable modeling and simulation of manufacturing methods, which will in turn allow manufacturing considerations to be included much earlier in the system development cycle. Significant cost savings, increased quality, and decreased manufacturing cycle time are expected to result. This paper will give an overview of the NASA's Intelligent Synthesis Environment, the agency initiative to develop an AEE, with a focus on the anticipated benefits in aerospace manufacturing.

  19. Advanced oxygen-hydrocarbon rocket engine study

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    This study identifies and evaluates promising LO2/HC rocket engine cycles, produces a consistent and reliable data base for vehicle optimization and design studies, demonstrates the significance of propulsion system improvements, and selects the critical technology areas necessary to realize an improved surface to orbit transportation system. Parametric LO2/HC engine data were generated over a range of thrust levels from 890 to 6672 kN (200K to 1.5M 1bF) and chamber pressures from 6890 to 34500 kN (1000 to 5000 psia). Engine coolants included RP-1, refined RP-1, LCH4, LC3H8, LO2, and LH2. LO2/RP-1 G.G. cycles were found to be not acceptable for advanced engines. The highest performing LO2/RP-1 staged combustion engine cycle utilizes LO2 as the coolant and incorporates an oxidizer rich preburner. The highest performing cycle for LO2/LCH4 and LO2/LC3H8 utilizes fuel cooling and incorporates both fuel and oxidizer rich preburners. LO2/HC engine cycles permitting the use of a third fluid LH2 coolant and an LH2 rich gas generator provide higher performance at significantly lower pump discharge pressures. The LO2/HC dual throat engine, because of its high altitude performance, delivers the highest payload for the vehicle configuration that was investigated.

  20. Development of Advanced Small Hydrogen Engines

    SciTech Connect

    Sapru, Krishna; Tan, Zhaosheng; Chao, Ben

    2010-09-30

    The main objective of the project is to develop advanced, low cost conversions of small (< 25 hp) gasoline internal combustion engines (ICEs) to run on hydrogen fuel while maintaining the same performance and durability. This final technical report summarizes the results of i) the details of the conversion of several small gasoline ICEs to run on hydrogen, ii) the durability test of a converted hydrogen engine and iii) the demonstration of a prototype bundled canister solid hydrogen storage system. Peak power of the hydrogen engine achieves 60% of the power output of the gasoline counterpart. The efforts to boost the engine power with various options including installing the over-sized turbocharger, retrofit of custom-made pistons with high compression ratio, an advanced ignition system, and various types of fuel injection systems are not realized. A converted Honda GC160 engine with ACS system to run with hydrogen fuel is successful. Total accumulative runtime is 785 hours. A prototype bundled canister solid hydrogen storage system having nominal capacity of 1.2 kg is designed, constructed and demonstrated. It is capable of supporting a wide range of output load of a hydrogen generator.

  1. Library of Advanced Materials for Engineering : LAME.

    SciTech Connect

    Hammerand, Daniel Carl; Scherzinger, William Mark

    2007-08-01

    Constitutive modeling is an important aspect of computational solid mechanics. Sandia National Laboratories has always had a considerable effort in the development of constitutive models for complex material behavior. However, for this development to be of use the models need to be implemented in our solid mechanics application codes. In support of this important role, the Library of Advanced Materials for Engineering (LAME) has been developed in Engineering Sciences. The library allows for simple implementation of constitutive models by model developers and access to these models by application codes. The library is written in C++ and has a very simple object oriented programming structure. This report summarizes the current status of LAME.

  2. NASA/GE quiet engine C acoustic test results

    NASA Technical Reports Server (NTRS)

    Kazin, S. B.; Pass, J. E.

    1974-01-01

    The acoustic investigation and evaluation of the C propulsion turbofan engine are discussed. The engine was built as a part of the Quiet Engine Program. The objectives of the program are as follows: (1) to determine the noise levels produced turbofan bypass engines, (2) to demonstrate the technology and innovations which will reduce the production and radiation of noise in turbofan engines, and (3) to acquire experimental acoustic and aerodynamic data for high bypass turbofan engines to provide a better understanding of noise production mechanisms. The goals of the program called for a turbofan engine 15 to 20 PNdB quieter than currently available engines in the same thrust class.

  3. Orbital transfer rocket engine technology: Advanced engine study

    NASA Technical Reports Server (NTRS)

    Hayden, Warren R.

    1992-01-01

    An advanced LOX/LH2 engine study for the use of NASA and vehicle prime contractors in developing concepts for manned missions to the Moon, Mars, and Phobos is documented. Parametric design data was obtained at five engine thrusts from 7.5K lbf to 50K lbf. Also, a separate task evaluated engine throttling over a 20:1 range and operation at a mixture ratio of 12 plus or minus 1 versus the 6 plus or minus 1 nominal. Cost data was also generated for DDT&E, first unit production, and factors in other life cycle costs. The major limitation of the study was lack of contact with vehicle prime contractors to resolve the issues in vehicle/engine interfaces. The baseline Aerojet dual propellant expander cycle was shown capable of meeting all performance requirements with an expected long operational life due to the high thermal margins. The basic engine design readily accommodated the 20:1 throttling requirement and operation up to a mixture ratio of 10 without change. By using platinum for baffled injector construction the increased thermal margin allowed operation up to mixture ratio 13. An initial engine modeling with an Aerojet transient simulation code (named MLETS) indicates stable engine operation with the baseline control system. A throttle ratio of 4 to 5 seconds from 10 percent to 100 percent thrust is also predicted. Performance predictions are 483.1 sec at 7.5K lbf, 487.3 sec at 20K lbf, and 485.2 sec at 50K lbf with a mixture ratio of 6 and an area ratio of 1200. Engine envelopes varied from 120 in. length/53 in. exit diameter at 7.5K lbf to 305 in. length/136 in. exit diameter at 50 K lbf. Packaging will be an important consideration. Continued work is recommended to include more vehicle prime contractor/engine contractor joint assessment of the interface issues.

  4. Ignition angle advancer for internal combustion engine

    SciTech Connect

    Yamazaki, T.

    1986-08-19

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

  5. Genome engineering in cattle: recent technological advancements.

    PubMed

    Wang, Zhongde

    2015-02-01

    Great strides in technological advancements have been made in the past decade in cattle genome engineering. First, the success of cloning cattle by somatic cell nuclear transfer (SCNT) or chromatin transfer (CT) is a significant advancement that has made obsolete the need for using embryonic stem (ES) cells to conduct cell-mediated genome engineering, whereby site-specific genetic modifications can be conducted in bovine somatic cells via DNA homologous recombination (HR) and whereby genetically engineered cattle can subsequently be produced by animal cloning from the genetically modified cells. With this approach, a chosen bovine genomic locus can be precisely modified in somatic cells, such as to knock out (KO) or knock in (KI) a gene via HR, a gene-targeting strategy that had almost exclusively been used in mouse ES cells. Furthermore, by the creative application of embryonic cloning to rejuvenate somatic cells, cattle genome can be sequentially modified in the same line of somatic cells and complex genetic modifications have been achieved in cattle. Very recently, the development of designer nucleases-such as zinc finger nucleases (ZFNs) and transcription activator-like effector nuclease (TALENs), and clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9)-has enabled highly efficient and more facile genome engineering in cattle. Most notably, by employing such designer nucleases, genomes can be engineered at single-nucleotide precision; this process is now often referred to as genome or gene editing. The above achievements are a drastic departure from the traditional methods of creating genetically modified cattle, where foreign DNAs are randomly integrated into the animal genome, most often along with the integrations of bacterial or viral DNAs. Here, I review the most recent technological developments in cattle genome engineering by highlighting some of the major achievements in creating genetically engineered

  6. Systems Engineering Building Advances Power Grid Research

    SciTech Connect

    Virden, Jud; Huang, Henry; Skare, Paul; Dagle, Jeff; Imhoff, Carl; Stoustrup, Jakob; Melton, Ron; Stiles, Dennis; Pratt, Rob

    2015-08-19

    Researchers and industry are now better equipped to tackle the nation’s most pressing energy challenges through PNNL’s new Systems Engineering Building – including challenges in grid modernization, buildings efficiency and renewable energy integration. This lab links real-time grid data, software platforms, specialized laboratories and advanced computing resources for the design and demonstration of new tools to modernize the grid and increase buildings energy efficiency.

  7. Distilling complexity to advance cardiac tissue engineering.

    PubMed

    Ogle, Brenda M; Bursac, Nenad; Domian, Ibrahim; Huang, Ngan F; Menasché, Philippe; Murry, Charles E; Pruitt, Beth; Radisic, Milica; Wu, Joseph C; Wu, Sean M; Zhang, Jianyi; Zimmermann, Wolfram-Hubertus; Vunjak-Novakovic, Gordana

    2016-06-01

    The promise of cardiac tissue engineering is in the ability to recapitulate in vitro the functional aspects of a healthy heart and disease pathology as well as to design replacement muscle for clinical therapy. Parts of this promise have been realized; others have not. In a meeting of scientists in this field, five central challenges or "big questions" were articulated that, if addressed, could substantially advance the current state of the art in modeling heart disease and realizing heart repair. PMID:27280684

  8. Bone tissue engineering: recent advances and challenges.

    PubMed

    Amini, Ami R; Laurencin, Cato T; Nukavarapu, Syam P

    2012-01-01

    The worldwide incidence of bone disorders and conditions has trended steeply upward and is expected to double by 2020, especially in populations where aging is coupled with increased obesity and poor physical activity. Engineered bone tissue has been viewed as a potential alternative to the conventional use of bone grafts, due to their limitless supply and no disease transmission. However, bone tissue engineering practices have not proceeded to clinical practice due to several limitations or challenges. Bone tissue engineering aims to induce new functional bone regeneration via the synergistic combination of biomaterials, cells, and factor therapy. In this review, we discuss the fundamentals of bone tissue engineering, highlighting the current state of this field. Further, we review the recent advances of biomaterial and cell-based research, as well as approaches used to enhance bone regeneration. Specifically, we discuss widely investigated biomaterial scaffolds, micro- and nano-structural properties of these scaffolds, and the incorporation of biomimetic properties and/or growth factors. In addition, we examine various cellular approaches, including the use of mesenchymal stem cells (MSCs), embryonic stem cells (ESCs), adult stem cells, induced pluripotent stem cells (iPSCs), and platelet-rich plasma (PRP), and their clinical application strengths and limitations. We conclude by overviewing the challenges that face the bone tissue engineering field, such as the lack of sufficient vascularization at the defect site, and the research aimed at functional bone tissue engineering. These challenges will drive future research in the field.

  9. Bone Tissue Engineering: Recent Advances and Challenges

    PubMed Central

    Amini, Ami R.; Laurencin, Cato T.; Nukavarapu, Syam P.

    2013-01-01

    The worldwide incidence of bone disorders and conditions has trended steeply upward and is expected to double by 2020, especially in populations where aging is coupled with increased obesity and poor physical activity. Engineered bone tissue has been viewed as a potential alternative to the conventional use of bone grafts, due to their limitless supply and no disease transmission. However, bone tissue engineering practices have not proceeded to clinical practice due to several limitations or challenges. Bone tissue engineering aims to induce new functional bone regeneration via the synergistic combination of biomaterials, cells, and factor therapy. In this review, we discuss the fundamentals of bone tissue engineering, highlighting the current state of this field. Further, we review the recent advances of biomaterial and cell-based research, as well as approaches used to enhance bone regeneration. Specifically, we discuss widely investigated biomaterial scaffolds, micro- and nano-structural properties of these scaffolds, and the incorporation of biomimetic properties and/or growth factors. In addition, we examine various cellular approaches, including the use of mesenchymal stem cells (MSCs), embryonic stem cells (ESCs), adult stem cells, induced pluripotent stem cells (iPSCs), and platelet-rich plasma (PRP), and their clinical application strengths and limitations. We conclude by overviewing the challenges that face the bone tissue engineering field, such as the lack of sufficient vascularization at the defect site, and the research aimed at functional bone tissue engineering. These challenges will drive future research in the field. PMID:23339648

  10. Advanced Propfan Engine Technology (APET) definition study, single and counter-rotation gearbox/pitch change mechanism design

    NASA Technical Reports Server (NTRS)

    Anderson, R. D.

    1985-01-01

    Single-rotation propfan-powered regional transport aircraft were studied to identify key technology development issues and programs. The need for improved thrust specific fuel consumption to reduce fuel burned and aircraft direct operating cost is the dominant factor. Typical cycle trends for minimizing fuel consumption are reviewed, and two 10,000 shp class engine configurations for propfan propulsion systems for the 1990's are presented. Recommended engine configurations are both three-spool design with dual spool compressors and free power turbines. The benefits of these new propulsion system concepts were evaluated using an advanced airframe, and results are compared for single-rotation propfan and turbofan advanced technology propulsion systems. The single-rotation gearbox is compared to a similar design with current technology to establish the benefits of the advanced gearbox technology. The conceptual design of the advanced pitch change mechanism identified a high pressure hydraulic system that is superior to the other contenders and completely external to the gearboxes.

  11. 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.

  12. Advanced general aviation engine/airframe integration study

    NASA Technical Reports Server (NTRS)

    Zmroczek, L. A.

    1982-01-01

    A comparison of the in-airframe performance and efficiency of the advanced engine concepts is presented. The results indicate that the proposed advanced engines can significantly improve the performance and economy of general aviation airplanes. The engine found to be most promising is the highly advanced version of a rotary combustion (Wankel) engine. The low weight and fuel consumption of this engine, as well as its small size, make it suited for aircraft use.

  13. Turbofan Acoustic Propagation and Radiation

    NASA Technical Reports Server (NTRS)

    Eversman, Walter

    2000-01-01

    This document describes progress in the development of finite element codes for the prediction of near and far field acoustic radiation from the inlet and aft fan ducts of turbofan engines. The report consists of nine papers which have appeared in archival journals and conference proceedings, or are presently in review for publication. Topics included are: 1. Aft Fan Duct Acoustic Radiation; 2. Mapped Infinite Wave Envelope Elements for Acoustic Radiation in a Uniformly Moving Medium; 3. A Reflection Free Boundary Condition for Propagation in Uniform Flow Using Mapped Infinite Wave Envelope Elements; 4. A Numerical Comparison Between Multiple-Scales and FEM Solution for Sound Propagation in Lined Flow Ducts; 5. Acoustic Propagation at High Frequencies in Ducts; 6. The Boundary Condition at an Impedance Wall in a Nonuniform Duct with Potential Flow; 7. A Reverse Flow Theorem and Acoustic Reciprocity in Compressible Potential Flows; 8. Reciprocity and Acoustics Power in One Dimensional Compressible Potential Flows; and 9. Numerical Experiments on Acoustic Reciprocity in Compressible Potential Flows.

  14. Parameterization of a Conventional and Regenerated UHB Turbofan

    NASA Astrophysics Data System (ADS)

    Oliveira, Fábio; Brójo, Francisco

    2015-09-01

    The attempt to improve aircraft engines efficiency resulted in the evolution from turbojets to the first generation low bypass ratio turbofans. Today, high bypass ratio turbofans are the most traditional type of engine in commercial aviation. Following many years of technological developments and improvements, this type of engine has proved to be the most reliable facing the commercial aviation requirements. In search of more efficiency, the engine manufacturers tend to increase the bypass ratio leading to ultra-high bypass ratio (UHB) engines. Increased bypass ratio has clear benefits in terms of propulsion system like reducing the specific fuel consumption. This study is aimed at a parametric analysis of a UHB turbofan engine focused on short haul flights. Two cycle configurations (conventional and regenerated) were studied, and estimated values of their specific fuel consumption (TSFC) and specific thrust (Fs) were determined. Results demonstrate that the regenerated cycle may contribute towards a more economic and friendly aero engines in a higher range of bypass ratio.

  15. Design approaches to more energy efficient engines

    NASA Technical Reports Server (NTRS)

    Saunders, N. T.; Colladay, R. S.; Macioce, L. E.

    1978-01-01

    The status of NASA's Energy Efficient Engine Project, a comparative government-industry effort aimed at advancing the technology base for the next generation of large turbofan engines for civil aircraft transports is summarized. Results of recently completed studies are reviewed. These studies involved selection of engine cycles and configurations that offer potential for at least 12% lower fuel consumption than current engines and also are economically attractive and environmentally acceptable. Emphasis is on the advancements required in component technologies and systems design concepts to permit future development of these more energy efficient engines.

  16. Recent Advances in Engineering Polyvalent Biological Interactions

    PubMed Central

    2015-01-01

    Polyvalent interactions, where multiple ligands and receptors interact simultaneously, are ubiquitous in nature. Synthetic polyvalent molecules, therefore, have the ability to affect biological processes ranging from protein–ligand binding to cellular signaling. In this review, we discuss recent advances in polyvalent scaffold design and applications. First, we will describe recent developments in the engineering of polyvalent scaffolds based on biomolecules and novel materials. Then, we will illustrate how polyvalent molecules are finding applications as toxin and pathogen inhibitors, targeting molecules, immune response modulators, and cellular effectors. PMID:25426695

  17. Advanced Engineering Technology for Measuring Performance.

    PubMed

    Rutherford, Drew N; D'Angelo, Anne-Lise D; Law, Katherine E; Pugh, Carla M

    2015-08-01

    The demand for competency-based assessments in surgical training is growing. Use of advanced engineering technology for clinical skills assessment allows for objective measures of hands-on performance. Clinical performance can be assessed in several ways via quantification of an assessee's hand movements (motion tracking), direction of visual attention (eye tracking), levels of stress (physiologic marker measurements), and location and pressure of palpation (force measurements). Innovations in video recording technology and qualitative analysis tools allow for a combination of observer- and technology-based assessments. Overall the goal is to create better assessments of surgical performance with robust validity evidence.

  18. Recent advances in bone tissue engineering scaffolds

    PubMed Central

    Bose, Susmita; Roy, Mangal; Bandyopadhyay, Amit

    2012-01-01

    Bone disorders are of significant concern due to increase in the median age of our population. Traditionally, bone grafts have been used to restore damaged bone. Synthetic biomaterials are now being used as bone graft substitutes. These biomaterials were initially selected for structural restoration based on their biomechanical properties. Later scaffolds were engineered to be bioactive or bioresorbable to enhance tissue growth. Now scaffolds are designed to induce bone formation and vascularization. These scaffolds are often porous, biodegradable materials that harbor different growth factors, drugs, genes or stem cells. In this review, we highlight recent advances in bone scaffolds and discuss aspects that still need to be improved. PMID:22939815

  19. Advanced concurrent-engineering environment. Final report

    SciTech Connect

    Jortner, J.N.; Friesen, J.A.

    1997-07-01

    Sandia demonstrated large-scale visualization in a conference room environment. Project focused in the installation of hardware for visualization and display, and the integration of software tools for design and animation of 3-dimensional parts. Using a high-end visualization server, 3-dimensional modeling and animation software, and leading edge World Wide Web technology, an advanced concurrent engineering environment was simulated where a design team was able to work collectively, rather than as solely disjoint individual efforts. Finally, a successful animation of a Sandia part was demonstrated, and a computer video generated. This video is now accessible on a Sandia internal web server.

  20. Advanced concurrent engineering environment final report

    SciTech Connect

    Jortner, J.N.; Friesen, J.A.; Schwegel, J.

    1997-08-01

    Sandia demonstrated large-scale visualization in a conference room environment. Project focused on the installation of hardware for visualization and display, and the integration of software tools for design and animation of 3-dimensional parts. Using a high-end visualization server, 3-dimensional modeling and animation software, and leading edge World Wide Web technology, and advanced concurrent engineering environment was simulated where a design team was able to work collectively, rather than as solely disjoint individual efforts. Finally, a successful animation of a Sandia part was demonstrated, and a computer video generated. This video is now accessible on a Sandia internal web server.

  1. Distilling complexity to advance cardiac tissue engineering

    PubMed Central

    Ogle, Brenda M.; Bursac, Nenad; Domian, Ibrahim; Huang, Ngan F; Menasché, Philippe; Murry, Charles; Pruitt, Beth; Radisic, Milica; Wu, Joseph C; Wu, Sean M; Zhang, Jianyi; Zimmermann, Wolfram-Hubertus; Vunjak-Novakovic, Gordana

    2016-01-01

    The promise of cardiac tissue engineering is in the ability to recapitulate in vitro the functional aspects of healthy heart and disease pathology as well as to design replacement muscle for clinical therapy. Parts of this promise have been realized; others have not. In a meeting of scientists in this field, five central challenges or “big questions” were articulated that, if addressed, could substantially advance the current state-of-the-art in modeling heart disease and realizing heart repair. PMID:27280684

  2. 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.

  3. Systems engineering and integration: Advanced avionics laboratories

    NASA Technical Reports Server (NTRS)

    1990-01-01

    In order to develop the new generation of avionics which will be necessary for upcoming programs such as the Lunar/Mars Initiative, Advanced Launch System, and the National Aerospace Plane, new Advanced Avionics Laboratories are required. To minimize costs and maximize benefits, these laboratories should be capable of supporting multiple avionics development efforts at a single location, and should be of a common design to support and encourage data sharing. Recent technological advances provide the capability of letting the designer or analyst perform simulations and testing in an environment similar to his engineering environment and these features should be incorporated into the new laboratories. Existing and emerging hardware and software standards must be incorporated wherever possible to provide additional cost savings and compatibility. Special care must be taken to design the laboratories such that real-time hardware-in-the-loop performance is not sacrificed in the pursuit of these goals. A special program-independent funding source should be identified for the development of Advanced Avionics Laboratories as resources supporting a wide range of upcoming NASA programs.

  4. Improved silicon carbide for advanced heat engines

    NASA Technical Reports Server (NTRS)

    Whalen, Thomas J.

    1988-01-01

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

  5. Improved silicon carbide for advanced heat engines

    NASA Technical Reports Server (NTRS)

    Whalen, Thomas J.

    1987-01-01

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

  6. [Advanced online search techniques and dedicated search engines for physicians].

    PubMed

    Nahum, Yoav

    2008-02-01

    In recent years search engines have become an essential tool in the work of physicians. This article will review advanced search techniques from the world of information specialists, as well as some advanced search engine operators that may help physicians improve their online search capabilities, and maximize the yield of their searches. This article also reviews popular dedicated scientific and biomedical literature search engines.

  7. 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.

  8. Using Simulated Debates to Teach History of Engineering Advances

    ERIC Educational Resources Information Center

    Reynolds, Terry S.

    1976-01-01

    Described is a technique for utilizing debates of past engineering controversies in the classroom as a means of teaching the history of engineering advances. Included is a bibliography for three debate topics relating to important controversies. (SL)

  9. Various advanced design projects promoting engineering education

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Universities Space Research Association (USRA) Advanced Design Program (ADP) program promotes engineering education in the field of design by presenting students with challenging design projects drawn from actual NASA interests. In doing so, the program yields two very positive results. Firstly, the students gain a valuable experience that will prepare them for design problems with which they will be faced in their professional careers. Secondly, NASA is able to use the work done by students as an additional resource in meeting its own design objectives. The 1994 projects include: Universal Test Facility; Automated Protein Crystal Growth Facility; Stiffening of the ACES Deployable Space Boom; Launch System Design for Access to Space; LH2 Fuel Tank Design for SSTO Vehicle; and Feed System Design for a Reduced Pressure Tank.

  10. Ceramic technology for advanced heat engines project

    SciTech Connect

    Not Available

    1990-09-01

    The Ceramic Technology for Advanced Heat Engines Project was developed by the Department of Energy's Office of Transportation Systems in Conservation and Renewable Energy. This project was developed to meet the ceramic technology requirements of the OTT's automotive technology programs. This project is managed by ORNL and is closely coordinated with complementary ceramics tasks funded by other DOE offices, NASA, DoD, and industry. Research is discussed under the following topics; Turbomilling of SiC Whiskers; microwave sintering of silicon nitride; and milling characterization; processing of monolithics; silicon nitride matrix; oxide matrix; silicate matrix; thermal and wear coatings; joining; design; contact interfaces; time-dependent behavior; environmental effects; fracture mechanics; nondestructive evaluation; and technology transfer. References, figures, and tables are included with each topic.

  11. Introduction to Advanced Engine Control Concepts

    NASA Technical Reports Server (NTRS)

    Sanjay, Garg

    2007-01-01

    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 at NASA (National Aeronautics and Space Administration) Glenn Research Center (GRC) in Cleveland, Ohio, is leading and participating in various projects in partnership with other organizations within GRC and across NASA, the U.S. aerospace industry, and academia to develop advanced controls and health management technologies that will help meet these challenges through the concept of Intelligent Propulsion Systems. The key enabling technologies for an Intelligent Propulsion System are the increased efficiencies of components through active control, advanced diagnostics and prognostics integrated with intelligent engine control to enhance operational reliability and component life, and distributed control with smart sensors and actuators in an adaptive fault tolerant architecture. This presentation describes the current activities of the Controls and Dynamics Branch in the areas of active component control and propulsion system intelligent control, and presents some recent analytical and experimental results in these areas.

  12. SAPLE: Sandia Advanced Personnel Locator Engine.

    SciTech Connect

    Procopio, Michael J.

    2010-04-01

    We present the Sandia Advanced Personnel Locator Engine (SAPLE) web application, a directory search application for use by Sandia National Laboratories personnel. SAPLE's purpose is to return Sandia personnel 'results' as a function of user search queries, with its mission to make it easier and faster to find people at Sandia. To accomplish this, SAPLE breaks from more traditional directory application approaches by aiming to return the correct set of results while placing minimal constraints on the user's query. Two key features form the core of SAPLE: advanced search query interpretation and inexact string matching. SAPLE's query interpretation permits the user to perform compound queries when typing into a single search field; where able, SAPLE infers the type of field that the user intends to search on based on the value of the search term. SAPLE's inexact string matching feature yields a high-quality ranking of personnel search results even when there are no exact matches to the user's query. This paper explores these two key features, describing in detail the architecture and operation of SAPLE. Finally, an extensive analysis on logged search query data taken from an 11-week sample period is presented.

  13. Utilizing numerical techniques in turbofan inlet acoustic suppressor design

    NASA Astrophysics Data System (ADS)

    Baumeister, K. J.

    Numerical theories in conjunction with previously published analytical results are used to augment current analytical theories in the acoustic design of a turbofan inlet nacelle. In particular, a finite element-integral theory is used to study the effect of the inlet lip radius on the far field radiation pattern and to determine the optimum impedance in an actual engine environment. For some single mode JT15D data, the numerical theory and experiment are found to be in a good agreement.

  14. 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.

  15. Ceramic applications in the advanced Stirling automotive engine

    NASA Technical Reports Server (NTRS)

    Tomazic, W. A.; Cairelli, J. E.

    1977-01-01

    The ideal cycle, its application to a practical machine, and the specific advantages of high efficiency, low emissions, multi-fuel capability, and low noise of the stirling engine are discussed. Certain portions of the Stirling engine must operate continuously at high temperature. Ceramics offer the potential of cost reduction and efficiency improvement for advanced engine applications. Potential applications for ceramics in Stirling engines, and some of the special problems pertinent to using ceramics in the Stirling engine are described. The research and technology program in ceramics which is planned to support the development of advanced Stirling engines is outlined.

  16. The GATE studies - Assessing the potential of future small general aviation turbine engines

    NASA Technical Reports Server (NTRS)

    Strack, W. C.

    1979-01-01

    Four studies have been completed that explore the opportunities for future General Aviation Turbine Engines (GATE) in the 150-1000 SHP class. These studies forecasted the potential impact of advanced technology turbine engines in the post-1988 market, identified important aircraft and missions, desirable engine sizes, engine performance and cost goals. Parametric evaluations of various engine cycles, configurations, design features, and advanced technology elements defined baseline conceptual engines for each of the important missions identified by the market analysis. Both fixed-wing and helicopter aircraft, and turboshaft, turboprop, and turbofan engines were considered. Key technology areas were recommended for NASA support in order to realize proposed improvements.

  17. Advanced oxygen-hydrocarbon rocket engine study

    NASA Technical Reports Server (NTRS)

    Obrien, C. J.; Salkeld, R.

    1980-01-01

    The advantages and disadvantages, system performance and operating limits, engine parametric data, and technology requirements for candidate high pressure LO2/Hydrocarbon engine systems are summarized. These summaries of parametric analysis and design provide a consistent engine system data base. Power balance data were generated for the eleven engine cycles. Engine cycle rating parameters were established and the desired condition and the effect of the parameter on the engine and/or vehicle are described.

  18. 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.

  19. Advanced propfan analysis for the family of commuter airplanes

    NASA Technical Reports Server (NTRS)

    Swift, Gerald A.; Creighton, Tom; Haddad, Raphael; Hendrich, Louis; Hensley, Doug; Morgan, Louise; Russell, Mark

    1987-01-01

    Advanced propfans were selected to be used throughout the family of commuters. These propulsion systems offer a 25 to 28 percent fuel savings over comparably sized turbofans operating in the 1990s. A brief study of the propulsion systems available for the family of commuters is provided and the selection of the advanced turboprops justified. The propeller and engine designs and performance are discussed. The integration of these designs are examined. Also addressed is the noise considerations and constraints due to propfan installation.

  20. Jet noise of an augmentor wing-advanced supersonic transport

    NASA Technical Reports Server (NTRS)

    Franciscus, L.

    1972-01-01

    A preliminary mission study was made of the range and jet noise of an advanced supersonic transport (AST) employing an augmentor wing and four duct burning turbofan engines. The airplane weight and aerodynamic characteristics of the Boeing 2707-300 airplane with a gross weight of 750,000 pounds and 234 passengers was used for the study. Engine thrust was fixed at 58,000 pounds per engine and engine size was increased to obtain the required thrust at reduced power settings for jet noise reduction. Turbofan engine core noise was reduced to FAR 36 noise levels and lower by proper selection of turbine inlet temperature, bypass ratio and fan pressure ratio. The study showed that an augmentor wing can reduce the bypass jet noise sufficiently so that total noise levels below FAR 36 can be attained without significant range penalties if the augmentor wing can be designed without severe weight and performance penalties.

  1. FY2014 Advanced Combustion Engine Annual Progress Report

    SciTech Connect

    2015-03-01

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

  2. The General Electric Advanced Course in Engineering.

    ERIC Educational Resources Information Center

    Mack, Donald R.

    A three-year, in-house engineering course offered to selected General Electric Company engineers is discussed. It is designed to develop the ability to identify and solve real engineering problems. The course may be taken concurrently with college courses in a cooperative program that can result in a graduate degree in engineering. (MLH)

  3. An airline study of advanced technology requirements for advanced high speed commercial transport engines. 1: Engine design study assessment

    NASA Technical Reports Server (NTRS)

    Sallee, G. P.

    1973-01-01

    The advanced technology requirements for an advanced high speed commercial tranport engine are presented. The results of the phase 1 study effort cover the following areas: (1) statement of an airline's major objectives for future transport engines, (2) airline's method of evaluating engine proposals, (3) description of an optimum engine for a long range subsonic commercial transport including installation and critical design features, (4) discussion of engine performance problems and experience with performance degradation, (5) trends in engine and pod prices with increasing technology and objectives for the future, (6) discussion of the research objectives for composites, reversers, advanced components, engine control systems, and devices to reduce the impact of engine stall, and (7) discussion of the airline objectives for noise and pollution reduction.

  4. Improved silicon nitride for advanced heat engines

    NASA Technical Reports Server (NTRS)

    Yeh, Hun C.; Fang, Ho T.

    1987-01-01

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

  5. Improved silicon carbide for advanced heat engines

    NASA Technical Reports Server (NTRS)

    Whalen, Thomas J.

    1989-01-01

    The development of high strength, high reliability silicon carbide parts with complex shapes suitable for use in advanced heat engines is studied. Injection molding was the forming method selected for the program because it is capable of forming complex parts adaptable for mass production on an economically sound basis. The goals were to reach a Weibull characteristic strength of 550 MPa (80 ksi) and a Weibull modulus of 16 for bars tested in four-point loading. Statistically designed experiments were performed throughout the program and a fluid mixing process employing an attritor mixer was developed. Compositional improvements in the amounts and sources of boron and carbon used and a pressureless sintering cycle were developed which provided samples of about 99 percent of theoretical density. Strengths were found to improve significantly by annealing in air. Strengths in excess of 550 MPa (80 ksi) with Weibull modulus of about 9 were obtained. Further improvements in Weibull modulus to about 16 were realized by proof testing. This is an increase of 86 percent in strength and 100 percent in Weibull modulus over the baseline data generated at the beginning of the program. Molding yields were improved and flaw distributions were observed to follow a Poisson process. Magic angle spinning nuclear magnetic resonance spectra were found to be useful in characterizing the SiC powder and the sintered samples. Turbocharger rotors were molded and examined as an indication of the moldability of the mixes which were developed in this program.

  6. 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.

  7. Fuel savings potential of the NASA Advanced Turboprop Program

    SciTech Connect

    Whitlow, J.B. Jr.; Sievers, G.K.

    1984-01-01

    The NASA Advanced Turboprop (ATP) Program is directed at developing new technology for highly loaded, multibladed propellers for use at Mach 0.65 to 0.85 and at altitudes compatible with the air transport system requirements. Advanced turboprop engines offer the potential of 15 to 30 percent savings in aircraft block fuel relative to advanced turbofan engines (50 to 60 percent savings over today's turbofan fleet). The concept, propulsive efficiency gains, block fuel savings and other benefits, and the program objectives through a systems approach are described. Current program status and major accomplishments in both single rotation and counter rotation propeller technology are addressed. The overall program from scale model wind tunnel tests to large scale flight tests on testbed aircraft is discussed.

  8. Advanced General Aviation Turbine Engine (GATE) concepts

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

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

  9. Smart Engines Via Advanced Model Based Controls

    SciTech Connect

    Allain, Marc

    2000-08-20

    A ''new'' process for developing control systems - Less engine testing - More robust control system - Shorter development cycle time - ''Smarter'' approach to engine control - On-board models describe engine behavior - Shorter, systematic calibration process - Customer and legislative requirements designed-in.

  10. FY 2007 Progress Report for Advanced Combustion Engine Technologies

    SciTech Connect

    None, None

    2007-12-01

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

  11. Orbit Transfer Vehicle (OTV) advanced expander cycle engine point design study. Task 7: Engine data summary

    NASA Technical Reports Server (NTRS)

    Christensen, K. L.

    1980-01-01

    A performance optimized engine system design for a man-rated advanced LOX/hydrogen expander cycle engine was investigated. The data are presented in tables, figures, and drawings. The following categories of data for the advanced expander cycle engine are presented: engine operating specification and pressure schedule; engine system layout drawing; major component layout drawings, including thrust chamber and nozzle, extendible nozzle actuating mechanism and seal, LOX turbopump, LOX boost pump, hydrogen turbopump, hydrogen boost pump, and propellant control valves; engine performance and service life prediction; engine weight; and engine envelope. The data represent updates based upon current results from the design and analyses tasks performed under contract. Futher iterations in the designs and data can be expected as the advanced expander cycle engine design matures.

  12. Advanced control for airbreathing engines, volume 1: Pratt and Whitney

    NASA Technical Reports Server (NTRS)

    Ralph, J. A.

    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 1 of these reports describes the studies performed by Pratt & Whitney.

  13. Advanced controls for airbreathing engines, volume 3: Allison gas turbine

    NASA Technical Reports Server (NTRS)

    Bough, R. M.

    1993-01-01

    The application of advanced control concepts to airbreathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for airbreathing 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 3 of these reports describes the studies performed by the Allison Gas Turbine Division.

  14. Systems Engineering Leadership Development: Advancing Systems Engineering Excellence

    NASA Technical Reports Server (NTRS)

    Hall, Phil; Whitfield, Susan

    2011-01-01

    This slide presentation reviews the Systems Engineering Leadership Development Program, with particular emphasis on the work being done in the development of systems engineers at Marshall Space Flight Center. There exists a lack of individuals with systems engineering expertise, in particular those with strong leadership capabilities, to meet the needs of the Agency's exploration agenda. Therefore there is a emphasis on developing these programs to identify and train systems engineers. The presentation reviews the proposed MSFC program that includes course work, and developmental assignments. The formal developmental programs at the other centers are briefly reviewed, including the Point of Contact (POC)

  15. Advances in biomedical engineering and biotechnology during 2013-2014.

    PubMed

    Liu, Feng; Wang, Ying; Burkhart, Timothy A; González Penedo, Manuel Francisco; Ma, Shaodong

    2014-01-01

    The 3rd International Conference on Biomedical Engineering and Biotechnology (iCBEB 2014), held in Beijing from the 25th to the 28th of September 2014, is an annual conference that intends to provide an opportunity for researchers and practitioners around the world to present the most recent advances and future challenges in the fields of biomedical engineering, biomaterials, bioinformatics and computational biology, biomedical imaging and signal processing, biomechanical engineering and biotechnology, amongst others. The papers published in this issue are selected from this conference, which witnesses the advances in biomedical engineering and biotechnology during 2013-2014.

  16. Thermal and Environmental Barrier Coatings for Advanced Propulsion Engine Systems

    NASA Technical Reports Server (NTRS)

    Zhu, Dong-Ming; Miller, Robert A.

    2004-01-01

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

  17. 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.

  18. 75 FR 62319 - Airworthiness Directives; Pratt & Whitney JT8D-9, -9A, -11, -15, -17, and -17R Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-08

    ..., Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park... Federal Register on May 19, 2010 (75 FR 27972). That action proposed to require overhauling fan blade... ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3)...

  19. Advancing Intercultural Competency: Canadian Engineering Employers' Experiences with Immigrant Engineers

    ERIC Educational Resources Information Center

    Friesen, Marcia; Ingram, Sandra

    2013-01-01

    This paper explores Canadian engineering employers' perceptions of and experiences with internationally educated engineers (recent immigrants to Canada) employed in their organisations for varying lengths of time. Qualitative data were collected from employers using focus group methodology. Findings reflected employers' observations of culturally…

  20. Extended frequency turbofan model

    NASA Technical Reports Server (NTRS)

    Mason, J. R.; Park, J. W.; Jaekel, R. F.

    1980-01-01

    The fan model was developed using two dimensional modeling techniques to add dynamic radial coupling between the core stream and the bypass stream of the fan. When incorporated into a complete TF-30 engine simulation, the fan model greatly improved compression system frequency response to planar inlet pressure disturbances up to 100 Hz. The improved simulation also matched engine stability limits at 15 Hz, whereas the one dimensional fan model required twice the inlet pressure amplitude to stall the simulation. With verification of the two dimensional fan model, this program formulated a high frequency F-100(3) engine simulation using row by row compression system characteristics. In addition to the F-100(3) remote splitter fan, the program modified the model fan characteristics to simulate a proximate splitter version of the F-100(3) engine.

  1. Advancing the Practice of Systems Engineering at JPL

    NASA Technical Reports Server (NTRS)

    Jones, Ross; Jansma, Patti A.; Derro, Mary Ellen; Burns, Margaret J.; Blom, Kris

    2007-01-01

    Systems Engineering Advancement (SEA) practices at the Jet Propulsion Laboratory is presented. The topics include: 1) SEA background; 2) Three Key Components of change; and 3) Three Support Components of Change.

  2. A Model to Assess the Risk of Ice Accretion Due to Ice Crystal Ingestion in a Turbofan Engine and its Effects on Performance

    NASA Technical Reports Server (NTRS)

    Jorgenson, Philip C. E.; Veres, Joseph P.; Wright, William B.; Struk, Peter M.

    2013-01-01

    The occurrence of ice accretion within commercial high bypass aircraft turbine engines has been reported under certain atmospheric conditions. Engine anomalies have taken place at high altitudes that were attributed to ice crystal ingestion, partially melting, and ice accretion on the compression system components. The result was one or more of the following anomalies: degraded engine performance, engine roll back, compressor surge and stall, and flameout of the combustor. The main focus of this research is the development of a computational tool that can estimate whether there is a risk of ice accretion by tracking key parameters through the compression system blade rows at all engine operating points within the flight trajectory. The tool has an engine system thermodynamic cycle code, coupled with a compressor flow analysis code, and an ice particle melt code that has the capability of determining the rate of sublimation, melting, and evaporation through the compressor blade rows. Assumptions are made to predict the complex physics involved in engine icing. Specifically, the code does not directly estimate ice accretion and does not have models for particle breakup or erosion. Two key parameters have been suggested as conditions that must be met at the same location for ice accretion to occur: the local wet-bulb temperature to be near freezing or below and the local melt ratio must be above 10%. These parameters were deduced from analyzing laboratory icing test data and are the criteria used to predict the possibility of ice accretion within an engine including the specific blade row where it could occur. Once the possibility of accretion is determined from these parameters, the degree of blockage due to ice accretion on the local stator vane can be estimated from an empirical model of ice growth rate and time spent at that operating point in the flight trajectory. The computational tool can be used to assess specific turbine engines to their susceptibility to

  3. Advancing intercultural competency: Canadian engineering employers' experiences with immigrant engineers

    NASA Astrophysics Data System (ADS)

    Friesen, Marcia; Ingram, Sandra

    2013-05-01

    This paper explores Canadian engineering employers' perceptions of and experiences with internationally educated engineers (recent immigrants to Canada) employed in their organisations for varying lengths of time. Qualitative data were collected from employers using focus group methodology. Findings reflected employers' observations of culturally different behaviours and characteristics in their internationally educated employees, employers' reactions to cultural differences ranging from negative attributions to tolerance, and the implementation of largely ad hoc intra-organisational strategies for managing cultural differences in employer-employee relationships. Findings exposed the lack of corporate intercultural competency in the Canadian engineering profession. Equity and gatekeeping implications are discussed.

  4. Performance analysis of a turbofan as a part of an airbreathing propulsion system for space shuttles

    NASA Astrophysics Data System (ADS)

    Steinebach, D. A.; Kuehl, W.; Gallus, H. E.

    1993-04-01

    This paper presents the results of the design and performance analysis of airbreathing engines for aerospace planes. The analysis is illustrated by introducing an exemplary twin-shaft turbofan engine with post-combustion and bypass-combustion. Some modules of the performance analysis algorithm such as inlet pressure recovery or real gas effects are also presented. The jet engine is designed in view of increasing temperatures at high flight Mach numbers. Hence, the engine design data are dependent on the characteristics of the available materials as well as on the trajectory of the aerospace plane. The results illustrate the strong influence of the real gas effects on the engine thrust particularly in the case of over-stoichiometric combustion of hydrogen. Turbofan engines offer the following advantages in comparison with equivalent turbojet engines: higher thrust performance in supersonic flight range and lower fuel consumption due to operation management of post-combustion and bypass-combustion.

  5. EGR Distribution in Engine Cylinders Using Advanced Virtual Simulation

    SciTech Connect

    Fan, Xuetong

    2000-08-20

    Exhaust Gas Recirculation (EGR) is a well-known technology for reduction of NOx in diesel engines. With the demand for extremely low engine out NOx emissions, it is important to have a consistently balanced EGR flow to individual engine cylinders. Otherwise, the variation in the cylinders' NOx contribution to the overall engine emissions will produce unacceptable variability. This presentation will demonstrate the effective use of advanced virtual simulation in the development of a balanced EGR distribution in engine cylinders. An initial design is analyzed reflecting the variance in the EGR distribution, quantitatively and visually. Iterative virtual lab tests result in an optimized system.

  6. Feasibility of magnetic bearings for advanced gas turbine engines

    NASA Technical Reports Server (NTRS)

    Hibner, David; Rosado, Lewis

    1992-01-01

    The application of active magnetic bearings to advanced gas turbine engines will provide a product with major improvements compared to current oil lubricated bearing designs. A rethinking of the engine rotating and static structure design is necessary and will provide the designer with significantly more freedom to meet the demanding goals of improved performance, increased durability, higher reliability, and increased thrust to weight ratio via engine weight reduction. The product specific technology necessary for this high speed, high temperature, dynamically complex application has been defined. The resulting benefits from this approach to aircraft engine rotor support and the complementary engine changes and improvements have been assessed.

  7. Small Engine Component Technology (SECT) study

    NASA Technical Reports Server (NTRS)

    Singh, B.

    1986-01-01

    Small advanced (450 to 850 pounds thrust, 2002 to 3781 N) gas turbine engines were studied for a subsonic strategic cruise missile application, using projected year 2000 technology. An aircraft, mission characteristics, and baseline (state-of-the-art) engine were defined to evaluate technology benefits. Engine performance and configuration analyses were performed for two and three spool turbofan and propfan engine concepts. Mission and Life Cycle Cost (LCC) analyses were performed in which the candidate engines were compared to the baseline engines over a prescribed mission. The advanced technology engines reduced system LCC up to 41 percent relative to the baseline engine. Critical aerodynamic, materials, and mechanical systems turbine engine technologies were identified and program plans were defined for each identified critical technology.

  8. Advanced Gasoline Turbocharged Direction Injection (GTDI) Engine Development

    SciTech Connect

    Wagner, Terrance

    2015-12-31

    This program was undertaken in response to US Department of Energy Solicitation DE-FOA-0000079, resulting in a cooperative agreement with Ford and MTU to demonstrate improvement of fuel efficiency in a vehicle equipped with an advanced GTDI engine. Ford Motor Company has invested significantly in GTDI engine technology as a cost effective, high volume, fuel economy solution, marketed globally as EcoBoost technology. Ford envisions additional fuel economy improvement in the medium and long term by further advancing EcoBoost technology. The approach for the project was to engineer a comprehensive suite of gasoline engine systems technologies to achieve the project objectives, and to progressively demonstrate the objectives via concept analysis / computer modeling, single-cylinder and multi-cylinder engine testing on engine dynamometer, and vehicle level testing on chassis rolls.

  9. Turbofans turn to UHB propulsion

    SciTech Connect

    Gray, D.E.; Conliffe, C.H. General Electric Co., Fairfield, CT )

    1990-07-01

    While ducted fan engines typical of current transport aircraft practice are able to achieve bypass ratios of the order of between 10 and 20 at most, the full benefits of bypass ratio maximization are only achievable at ratios of the order of 30 to 50, which require open-fan configurations. An account is presently given of the development status of the two fundamentally different ultrahigh bypass (UHB) engine designs currently undergoing testing: one of which uses a gearbox, while the other relies on a contrarotating turbine configuration to achieve the requisite speed reduction. Both engines have undergone flight testing on an MD-80 airliner. Additional advanced UHB engine development programs undertaken by foreign manufacturers are noted.

  10. Advanced Turboprop Project

    NASA Technical Reports Server (NTRS)

    Hager, Roy D.; Vrabel, Deborah

    1988-01-01

    At the direction of Congress, a task force headed by NASA was organized in 1975 to identify potential fuel saving concepts for aviation. The result was the Aircraft Energy Efficiency (ACEE) Program implemented in 1976. An important part of the program was the development of advanced turboprop technology for Mach 0.65 to 0.85 applications having the potential fuel saving of 30 to 50 percent relative to existing turbofan engines. A historical perspective is presented of the development and the accomplishments that brought the turboprop to successful flight tests in 1986 and 1987.

  11. Advanced turboprop project

    SciTech Connect

    Hager, R.D.; Vrabel, D.

    1988-01-01

    At the direction of Congress, a task force headed by NASA was organized in 1975 to identify potential fuel saving concepts for aviation. The result was the Aircraft Energy Efficiency (ACEE) Program implemented in 1976. An important part of the program was the development of advanced turboprop technology for Mach 0.65 to 0.85 applications having the potential fuel saving of 30 to 50 percent relative to existing turbofan engines. A historical perspective is presented of the development and the accomplishments that brought the turboprop to successful flight tests in 1986 and 1987.

  12. ADVANCED COMPRESSOR ENGINE CONTROLS TO ENHANCE OPERATION, RELIABILITY AND INTEGRITY

    SciTech Connect

    Gary D. Bourn; Jess W. Gingrich; Jack A. Smith

    2004-03-01

    This document is the final report for the ''Advanced Compressor Engine Controls to Enhance Operation, Reliability, and Integrity'' project. SwRI conducted this project for DOE in conjunction with Cooper Compression, under DOE contract number DE-FC26-03NT41859. This report addresses an investigation of engine controls for integral compressor engines and the development of control strategies that implement closed-loop NOX emissions feedback.

  13. Full 3D Analysis of the GE90 Turbofan Primary Flowpath

    NASA Technical Reports Server (NTRS)

    Turner, Mark G.

    2000-01-01

    The multistage simulations of the GE90 turbofan primary flowpath components have been performed. The multistage CFD code, APNASA, has been used to analyze the fan, fan OGV and booster, the 10-stage high-pressure compressor and the entire turbine system of the GE90 turbofan engine. The code has two levels of parallel, and for the 18 blade row full turbine simulation has 87.3 percent parallel efficiency with 121 processors on an SGI ORIGIN. Grid generation is accomplished with the multistage Average Passage Grid Generator, APG. Results for each component are shown which compare favorably with test data.

  14. 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.

  15. Aero-acoustic tests of duct-burning turbofan exhaust nozzles

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Packman, A. B.

    1976-01-01

    The acoustic and aerodynamic characteristics of several exhaust systems suitable for duct burning turbofan engines are evaluated. Scale models representing unsuppressed coannular exhaust systems are examined statically under varying exhaust conditions. Ejectors with both hardwall and acoustically treated inserts are investigated.

  16. 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.

  17. Rocket Engine Innovations Advance Clean Energy

    NASA Technical Reports Server (NTRS)

    2012-01-01

    During launch countdown, at approximately T-7 seconds, the Space Shuttle Main Engines (SSMEs) roar to life. When the controllers indicate normal operation, the solid rocket boosters ignite and the shuttle blasts off. Initially, the SSMEs throttle down to reduce stress during the period of maximum dynamic pressure, but soon after, they throttle up to propel the orbiter to 17,500 miles per hour. In just under 9 minutes, the three SSMEs burn over 1.6 million pounds of propellant, and temperatures inside the main combustion chamber reach 6,000 F. To cool the engines, liquid hydrogen circulates through miles of tubing at -423 F. From 1981to 2011, the Space Shuttle fleet carried crew and cargo into orbit to perform a myriad of unprecedented tasks. After 30 years and 135 missions, the feat of engineering known as the SSME boasted a 100-percent flight success rate.

  18. Phase 2 program on ground test of refanned JT8D turbofan engines and nacelles for the 727 airplane. Volume 3: Ground tests

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The NASA Refan Program included full-scale performance and noise ground tests of both a current production (JT8D-15) and a refanned (JT8D-115) engine. A description of the two ground tests including detailed propulsion, noise, and structural test results is presented. The primary objectives of the total test program were comparison of JT8D-15 and JT8D-115 overall propulsion system performance and noise characteristics and determination of incremental component noise levels. Other objectives of the test program included: (1) determination of acoustic treatment effectiveness; (2) measurement of internal sound pressure levels; (3) measurement of inlet and exhaust hardware performance; (4) determination of center-engine surge margin; and (5) evaluation of certain structural characteristics associated with the 727 refan center-engine inlet duct and JT8D refan engine exhaust system. The JT8D-15 and -115 tests were conducted during September 1974 and January to March 1975, respectively. Analyses of the test data indicated that the JT8D-115, as compared to the JT8D-15, demonstrates a 12.5 percent to 13.2 percent reduction in static specific fuel consumption, and a reduction of 6 to 7 PNdB in a weighted average value of static tone corrected perceived noise level. Separated into noise components, a significant reduction was shown for the inlet fan, aft fan, exhaust duct flow, turbine, and jet noises. However, core noise was increased. Photographs of test stands and test equipment are shown.

  19. 75 FR 34924 - Airworthiness Directives; CFM International, S.A. CFM56-5, -5B, and -7B Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ..., 2010 (75 FR 13045). That action proposed to require removing from service, nine stage 3 LPT disks... CFM56-5C engines, and use a different disk P/N not affected by this AD. We agree. We removed the A340... applicability paragraph to help identify the parts to be removed. We agree. We added the disk part number to...

  20. 75 FR 13045 - Airworthiness Directives; CFM International, S.A. CFM56-5, -5B, and -7B Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-18

    ... requiring removal of the disk before the certified disk life of certain stage 3 LPT disks. We are proposing... Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78). Examining the AD Docket You... service of the suspect disks before their certified life limits. Operating engines with these...

  1. Advanced general aviation comparative engine/airframe integration study

    NASA Technical Reports Server (NTRS)

    Huggins, G. L.; Ellis, D. R.

    1981-01-01

    The NASA Advanced Aviation Comparative Engine/Airframe Integration Study was initiated to help determine which of four promising concepts for new general aviation engines for the 1990's should be considered for further research funding. The engine concepts included rotary, diesel, spark ignition, and turboprop powerplants; a conventional state-of-the-art piston engine was used as a baseline for the comparison. Computer simulations of the performance of single and twin engine pressurized aircraft designs were used to determine how the various characteristics of each engine interacted in the design process. Comparisons were made of how each engine performed relative to the others when integrated into an airframe and required to fly a transportation mission.

  2. Advanced supersonic technology propulsion system study

    NASA Technical Reports Server (NTRS)

    Szeliga, R.; Allan, R. D.

    1974-01-01

    This study had the objectives of determining the most promising conventional and variable cycle engine types; the effect of design cruise Mach number (2.2, 2.7 and 3.2) on a commercial supersonic transport; effect of advanced engine technology on the choice of engine cycle; and effect of utilizing hydrogen as the engine fuel. The technology required for the engines was defined, and the levels of development to ensure availability of this technology in advanced aircraft propulsion systems were assessed. No clearcut best conventional or variable cycle engine was identified. The dry bypass turbojet and the duct burning turbofans were initially selected as the best conventional engines, but later results, utilizing augmentation at takeoff, added the mixed-flow augmented turbofan as a promising contender. The modulating air flow, three-rotor variable cycle engine identified the performance features desired from VCE concepts (elimination of inlet drag and reduction in afterbody drag), but was a very heavy and complex engine.

  3. Screening studies of advanced control concepts for airbreathing engines

    NASA Technical Reports Server (NTRS)

    Ouzts, Peter J.; Lorenzo, Carl F.; Merrill, Walter C.

    1993-01-01

    The application of advanced control concepts to airbreathing engines may yield significant improvements in aircraft/engine performance and operability. Accordingly, the NASA Lewis Research Center has conducted screening studies of advanced control concepts for airbreathing engines to determine their potential impact 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 concepts was formulated by NASA and industry. These concepts were evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation, three target 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 were defined and described. The concept's potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts were also determined. Finally, the concepts were ranked with respect to the target aircraft/engine missions.

  4. Screening studies of advanced control concepts for airbreathing engines

    NASA Technical Reports Server (NTRS)

    Ouzts, Peter J.; Lorenzo, Carl F.; Merrill, Walter C.

    1992-01-01

    The application of advanced control concepts to airbreathing engines may yield significant improvements in aircraft/engine performance and operability. Accordingly, the NASA Lewis Research Center has conducted screening studies of advanced control concepts for airbreathing engines to determine their potential impact 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 concepts was formulated by NASA and industry. These concepts were evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation, three target 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 were defined and described. The concept's potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts were also determined. Finally, the concepts were ranked with respect to the target aircraft/engine missions.

  5. Advanced oxygen-hydrocarbon rocket engine study

    NASA Technical Reports Server (NTRS)

    Obrien, C. J.; Salkeid, R.; Mueggenburg, H.; Ewen, R. L.

    1980-01-01

    Preliminary identification and evaluation of promising LO2/Hydrocarbon rocket engine cycles were used to produce a consistent and reliable data base for vehicle optimization and design studies. cycles G and C were chosen for design analysis. Preliminary design analysis of the heat transfer subsystem was performed to establish major technology requirements.

  6. An airline study of advanced technology requirements for advanced high speed commercial transport engines. 2: Engine preliminary design assessment

    NASA Technical Reports Server (NTRS)

    Sallee, G. P.

    1973-01-01

    The advanced technology requirements for an advanced high speed commercial transport engine are presented. The results of the phase 2 study effort cover the following areas: (1) general review of preliminary engine designs suggested for a future aircraft, (2) presentation of a long range view of airline propulsion system objectives and the research programs in noise, pollution, and design which must be undertaken to achieve the goals presented, (3) review of the impact of propulsion system unreliability and unscheduled maintenance on cost of operation, (4) discussion of the reliability and maintainability requirements and guarantees for future engines.

  7. Advances in knowledge-based software engineering

    NASA Technical Reports Server (NTRS)

    Truszkowski, Walt

    1991-01-01

    The underlying hypothesis of this work is that a rigorous and comprehensive software reuse methodology can bring about a more effective and efficient utilization of constrained resources in the development of large-scale software systems by both government and industry. It is also believed that correct use of this type of software engineering methodology can significantly contribute to the higher levels of reliability that will be required of future operational systems. An overview and discussion of current research in the development and application of two systems that support a rigorous reuse paradigm are presented: the Knowledge-Based Software Engineering Environment (KBSEE) and the Knowledge Acquisition fo the Preservation of Tradeoffs and Underlying Rationales (KAPTUR) systems. Emphasis is on a presentation of operational scenarios which highlight the major functional capabilities of the two systems.

  8. Advanced Engineering Environments for Space Transportation System Development

    NASA Technical Reports Server (NTRS)

    Thomas, L. Dale; Smith, Charles A.; Beveridge, James

    2000-01-01

    There are significant challenges facing today's launch vehicle industry. Global competition, more complex products, geographically-distributed design teams, demands for lower cost, higher reliability and safer vehicles, and the need to incorporate the latest technologies quicker, all face the developer of a space transportation system. Within NASA, multiple technology development and demonstration projects are underway toward the objectives of safe, reliable, and affordable access to space. New information technologies offer promising opportunities to develop advanced engineering environments to meet these challenges. Significant advances in the state-of-the-art of aerospace engineering practice are envisioned in the areas of engineering design and analytical tools, cost and risk tools, collaborative engineering, and high-fidelity simulations early in the development cycle. At the Marshall Space Flight Center, work has begun on development of an advanced engineering environment specifically to support the design, modeling, and analysis of space transportation systems. This paper will give an overview of the challenges of developing space transportation systems in today's environment and subsequently discuss the advanced engineering environment and its anticipated benefits.

  9. Ultra Efficient Engine Technology Systems Integration and Environmental Assessment

    NASA Technical Reports Server (NTRS)

    Daggett, David L.; Geiselhart, Karl A. (Technical Monitor)

    2002-01-01

    This study documents the design and analysis of four types of advanced technology commercial transport airplane configurations (small, medium large and very large) with an assumed technology readiness date of 2010. These airplane configurations were used as a platform to evaluate the design concept and installed performance of advanced technology engines being developed under the NASA Ultra Efficient Engine Technology (UEET) program. Upon installation of the UEET engines onto the UEET advanced technology airframes, the small and medium airplanes both achieved an additional 16% increase in fuel efficiency when using GE advanced turbofan engines. The large airplane achieved an 18% increase in fuel efficiency when using the P&W geared fan engine. The very large airplane (i.e. BWB), also using P&W geared fan engines, only achieved an additional 16% that was attributed to a non-optimized airplane/engine combination.

  10. Advanced Materials Development Program: Ceramic Technology for Advanced Heat Engines program plan, 1983--1993

    SciTech Connect

    Not Available

    1990-07-01

    The purpose of the Ceramic Technology for Advanced Heat Engines (CTAHE) Project is the development of an industrial technology base capable of providing reliable and cost-effective high temperature ceramic components for application in advanced heat engines. There is a deliberate emphasis on industrial'' in the purpose statement. The project is intended to support the US ceramic and engine industries by providing the needed ceramic materials technology. The heat engine programs have goals of component development and proof-of-concept. The CTAHE Project is aimed at developing generic basic ceramic technology and does not involve specific engine designs and components. The materials research and development efforts in the CTAHE Project are focused on the needs and general requirements of the advanced gas turbine and low heat rejection diesel engines. The CTAHE Project supports the DOE Office of Transportation Systems' heat engine programs, Advanced Turbine Technology Applications (ATTAP) and Heavy Duty Transport (HDT) by providing the basic technology required for development of reliable and cost-effective ceramic components. The heat engine programs provide the iterative component design, fabrication, and test development logic. 103 refs., 18 figs., 11 tabs.

  11. Caterpillar`s advanced reciprocating engine for distributed generation markets

    SciTech Connect

    Gerber, G.; Brandes, D.; Reinhart, M.; Nagel, G.; Wong, E.

    1999-11-01

    Competition in energy markets and federal and state policy advocating clean, advanced technologies as means to achieve environmental and global climate change goals are clear drivers to original equipment manufacturers of prime movers. Underpinning competition are the principle of consumer choice to facilitate retail competition, and the desire to improve system and grid reliability. Caterpillar`s Gas Engine Division is responding to the market`s demand for a more efficient, lower lifecycle cost engine with reduced emissions. Cat`s first generation TARGET engine will be positioned to effectively serve distributed generation and combined heat and power (CHP) applications. TARGET (The Advanced Reciprocating Gas Engine Technology) will embody Cat`s product attributes: durability, reliability, and competitively priced life cycle cost products. Further, Caterpillar`s nationwide, fully established dealer sales and service ensure continued product support subsequent to the sale and installation of the product.

  12. Cofactor engineering for advancing chemical biotechnology.

    PubMed

    Wang, Yipeng; San, Ka-Yiu; Bennett, George N

    2013-12-01

    Cofactors provide redox carriers for biosynthetic reactions, catabolic reactions and act as important agents in transfer of energy for the cell. Recent advances in manipulating cofactors include culture conditions or additive alterations, genetic modification of host pathways for increased availability of desired cofactor, changes in enzyme cofactor specificity, and introduction of novel redox partners to form effective circuits for biochemical processes and biocatalysts. Genetic strategies to employ ferredoxin, NADH and NADPH most effectively in natural or novel pathways have improved yield and efficiency of large-scale processes for fuels and chemicals and have been demonstrated with a variety of microbial organisms.

  13. Microbial engineering for the production of advanced biofuels.

    PubMed

    Peralta-Yahya, Pamela P; Zhang, Fuzhong; del Cardayre, Stephen B; Keasling, Jay D

    2012-08-16

    Advanced biofuels produced by microorganisms have similar properties to petroleum-based fuels, and can 'drop in' to the existing transportation infrastructure. However, producing these biofuels in yields high enough to be useful requires the engineering of the microorganism's metabolism. Such engineering is not based on just one specific feedstock or host organism. Data-driven and synthetic-biology approaches can be used to optimize both the host and pathways to maximize fuel production. Despite some success, challenges still need to be met to move advanced biofuels towards commercialization, and to compete with more conventional fuels.

  14. Bioreactors Drive Advances in Tissue Engineering

    NASA Technical Reports Server (NTRS)

    2012-01-01

    It was an unlikely moment for inspiration. Engineers David Wolf and Ray Schwarz stopped by their lab around midday. Wolf, of Johnson Space Center, and Schwarz, with NASA contractor Krug Life Sciences (now Wyle Laboratories Inc.), were part of a team tasked with developing a unique technology with the potential to enhance medical research. But that wasn t the focus at the moment: The pair was rounding up colleagues interested in grabbing some lunch. One of the lab s other Krug engineers, Tinh Trinh, was doing something that made Wolf forget about food. Trinh was toying with an electric drill. He had stuck the barrel of a syringe on the bit; it spun with a high-pitched whirr when he squeezed the drill s trigger. At the time, a multidisciplinary team of engineers and biologists including Wolf, Schwarz, Trinh, and project manager Charles D. Anderson, who formerly led the recovery of the Apollo capsules after splashdown and now worked for Krug was pursuing the development of a technology called a bioreactor, a cylindrical device used to culture human cells. The team s immediate goal was to grow human kidney cells to produce erythropoietin, a hormone that regulates red blood cell production and can be used to treat anemia. But there was a major barrier to the technology s success: Moving the liquid growth media to keep it from stagnating resulted in turbulent conditions that damaged the delicate cells, causing them to quickly die. The team was looking forward to testing the bioreactor in space, hoping the device would perform more effectively in microgravity. But on January 28, 1986, the Space Shuttle Challenger broke apart shortly after launch, killing its seven crewmembers. The subsequent grounding of the shuttle fleet had left researchers with no access to space, and thus no way to study the effects of microgravity on human cells. As Wolf looked from Trinh s syringe-capped drill to where the bioreactor sat on a workbench, he suddenly saw a possible solution to both

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

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  16. Evaluation of advanced displays for engine monitoring and control

    NASA Technical Reports Server (NTRS)

    Summers, L. G.

    1993-01-01

    The relative effectiveness of two advanced display concepts for monitoring engine performance for commercial transport aircraft was studied. The concepts were the Engine Monitoring and Control System (EMACS) display developed by NASA Langley and a display by exception design. Both of these concepts were based on the philosophy of providing information that is directly related to the pilot's task. Both concepts used a normalized thrust display. In addition, EMACS used column deviation indicators; i.e., the difference between the actual parameter value and the value predicted by an engine model, for engine health monitoring; while the Display by Exception displayed the engine parameters if the automated system detected a difference between the actual and the predicted values. The results showed that the advanced display concepts had shorter detection and response times. There were no differences in any of the results between manual and auto throttles. There were no effects upon perceived workload or performance on the primary flight task. The majority of pilots preferred the advanced displays and thought they were operationally acceptable. Certification of these concepts depends on the validation of the engine model. Recommendations are made to improve both the EMACS and the display by exception display formats.

  17. Improved silicon nitride for advanced heat engines

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  18. Recent advances in nerve tissue engineering.

    PubMed

    Zhang, Bill G X; Quigley, Anita F; Myers, Damian E; Wallace, Gordon G; Kapsa, Robert M I; Choong, Peter F M

    2014-04-01

    Nerve injury secondary to trauma, neurological disease or tumor excision presents a challenge for surgical reconstruction. Current practice for nerve repair involves autologous nerve transplantation, which is associated with significant donor-site morbidity and other complications. Previously artificial nerve conduits made from polycaprolactone, polyglycolic acid and collagen were approved by the FDA (USA) for nerve repair. More recently, there have been significant advances in nerve conduit design that better address the requirements of nerve regrowth. Innovations in materials science, nanotechnology, and biology open the way for the synthesis of new generation nerve repair conduits that address issues currently faced in nerve repair and regeneration. This review discusses recent innovations in this area, including the use of nanotechnology to improve the design of nerve conduits and to enhance nerve regeneration.

  19. Advances in refrigeration and heat transfer engineering

    SciTech Connect

    Bansal, Pradeep; Cremaschi, Prof. Lorenzo

    2015-05-13

    This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO2 may perhaps have been the most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).

  20. Powder metallurgy bearings for advanced rocket engines

    NASA Technical Reports Server (NTRS)

    Fleck, J. N.; Killman, B. J.; Munson, H.E.

    1985-01-01

    Traditional ingot metallurgy was pushed to the limit for many demanding applications including antifriction bearings. New systems require corrosion resistance, better fatigue resistance, and higher toughness. With conventional processing, increasing the alloying level to achieve corrosion resistance results in a decrease in other properties such as toughness. Advanced powder metallurgy affords a viable solution to this problem. During powder manufacture, the individual particle solidifies very rapidly; as a consequence, the primary carbides are very small and uniformly distributed. When properly consolidated, this uniform structure is preserved while generating a fully dense product. Element tests including rolling contact fatigue, hot hardness, wear, fracture toughness, and corrosion resistance are underway on eleven candidate P/M bearing alloys and results are compared with those for wrought 440C steel, the current SSME bearing material. Several materials which offer the promise of a significant improvement in performance were identified.