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Sample records for advanced turboprop aircraft

  1. A review of advanced turboprop transport aircraft

    NASA Astrophysics Data System (ADS)

    Lange, Roy H.

    The application of advanced technologies shows the potential for significant improvement in the fuel efficiency and operating costs of future transport aircraft envisioned for operation in the 1990s time period. One of the more promising advanced technologies is embodied in an advanced turboprop concept originated by Hamilton Standard and NASA and known as the propfan. The propfan concept features a highly loaded multibladed, variable pitch propeller geared to a high pressure ratio gas turbine engine. The blades have high sweepback and advanced airfoil sections to achieve 80 percent propulsive efficiency at M=0.80 cruise speed. Aircraft system studies have shown improvements in fuel efficiency of 15-20 percent for propfan advanced transport aircraft as compared to equivalent turbofan transports. Beginning with the Lockheed C-130 and Electra turboprop aircraft, this paper presents an overview of the evolution of propfan aircraft design concepts and system studies. These system studies include possible civil and military transport applications and data on the performance, community and far-field noise characteristics and operating costs of propfan aircraft design concepts. NASA Aircraft Energy Efficiency (ACEE) program propfan projects with industry are reviewed with respect to system studies of propfan aircraft and recommended flight development programs.

  2. Structureborne noise control in advanced turboprop aircraft

    NASA Astrophysics Data System (ADS)

    Loeffler, Irvin J.

    1987-01-01

    Structureborne noise is discussed as a contributor to propeller aircraft interior noise levels that are nonresponsive to the application of a generous amount of cabin sidewall acoustic treatment. High structureborne noise levels may jeopardize passenger acceptance of the fuel-efficient high-speed propeller transport aircraft designed for cruise at Mach 0.65 to 0.85. These single-rotation tractor and counter-rotation tractor and pusher propulsion systems will consume 15 to 30 percent less fuel than advanced turbofan systems. Structureborne noise detection methodologies and the importance of development of a structureborne noise sensor are discussed. A structureborne noise generation mechanism is described in which the periodic components or propeller swirl produce periodic torques and forces on downstream wings and airfoils that are propagated to the cabin interior as noise. Three concepts for controlling structureborne noise are presented: (1) a stator row swirl remover, (2) selection of a proper combination of blade numbers in the rotor/stator system of a single-rotation propeller, and the rotor/rotor system of a counter-rotation propeller, and (3) a tuned mechanical absorber.

  3. Advanced turboprop aircraft flyover noise annoyance - Comparison of different propeller configurations

    NASA Technical Reports Server (NTRS)

    Mccurdy, David A.

    1989-01-01

    A laboratory experiment was conducted to compare the annoyance of flyover noise from advanced turboprop aircraft having different propeller configurations with the annoyance of conventional turboprop and jet aircraft flyover noise. It was found that advanced turboprops with single-rotating propellers were, on average, slightly less annoying than the other aircraft. Fundamental frequency and tone-to-broadband noise ratio affected annoyance response to advanced turboprops but the effects varied with propeller configuration and noise metric. The addition of duration corrections and corrections for tones above 500 Hz to the noise measurement procedures improved prediction ability.

  4. Quantification of advanced turboprop aircraft flyover noise annoyance

    NASA Technical Reports Server (NTRS)

    Mccurdy, D. A.

    1984-01-01

    A laboratory experiment was conducted to quantify the annoyance to advanced turboprop (propfan) aircraft flyover noise. A computer synthesis system was used to generate 45 realistic, time varying simulations of propeller aircraft flyover noise in which the tonal content was systematically varied to represent the factorial combinations of five fundamental frequencies, three frequency envelope shapes, and three tone-to-broadband noise ratios. In the experiment, 64 subjects judged the annoyance of recordings of the 45 synthesized flyover noises presented at three sound levels in a test facility which simulates the outdoor acoustic environment. Analyses of the judgements showed that frequency envelope shape did not significantly affect annoyance. The interaction of fundamental frequency with tone-to-broadband noise ratio did have a large and complex effect on annoyance. Duration corrected A-weighted sound pressure level with a modified tone correction predicted annoyance better than any other measurement procedure.

  5. Annoyance caused by advanced turboprop aircraft flyover noise: Comparison of different propeller configurations

    NASA Technical Reports Server (NTRS)

    Mccurdy, David A.

    1991-01-01

    A laboratory experiment was conducted to compare the annoyance of flyover noise from advanced turboprop aircraft having different propeller configurations with the annoyance of conventional turboprop and turbofan aircraft flyover noise. A computer synthesis system was used to generate 40 realistic, time varying simulations of advanced turboprop takeoff noise. Of the 40 noises, single-rotating propeller configurations (8) and counter-rotating propeller configurations with an equal (12) and unequal (20) number of blades on each rotor were represented. Analyses found that advanced turboprops with single-rotating propellers were, on average, slightly less annoying than the other aircraft. Fundamental frequency and tone-to-broadband noise ratio affected annoyance response to advanced turboprops, but the effects varied with propeller configuration and noise metric. The addition of duration corrections and corrections for tones above 500 Hz to the noise measurement procedures improved annoyance prediction ability.

  6. Annoyance caused by advanced turboprop aircraft flyover noise: Single-rotating propeller configuration

    NASA Technical Reports Server (NTRS)

    Mccurdy, David A.

    1988-01-01

    Two experiments were conducted to quantify the annoyance of people to advanced turboprop (propfan) aircraft flyover noise. The objectives were to: (1) determine the effects on annoyance of various tonal characteristics; and (2) compare annoyance to advanced turboprops with annoyance to conventional turboprops and jets. A computer was used to produce realistic, time-varying simulations of advanced turboprop aircraft takeoff noise. In the first experiment, subjects judged the annoyance of 45 advanced turboprop noises in which the tonal content was systematically varied to represent the factorial combinations of five fundamental frequencies, three frequency envelope shapes, and three tone-to-broadband noise ratios. Each noise was presented at three sound levels. In the second experiment, 18 advanced turboprop takeoffs, 5 conventional turboprop takeoffs, and 5 conventional jet takeoffs were presented at three sound pressure levels to subjects. Analysis indicated that frequency envelope shape did not significantly affect annoyance. The interaction of fundamental frequency with tone-to-broadband noise ratio did have a large and complex effect on annoyance. The advanced turboprop stimuli were slightly less annoying than the conventional stimuli.

  7. Comparison of advanced turboprop and conventional jet and propeller aircraft flyover noise annoyance: Preliminary results

    NASA Technical Reports Server (NTRS)

    Mccurdy, D. A.

    1985-01-01

    A laboratory experiment was conducted to compare the flyover noise annoyance of proposed advanced turboprop aircraft with that of conventional turboprop and jet aircraft. The effects of fundamental frequency and tone-to-broadband noise ratio on advanced turboprop annoyance were also examined. A computer synthesis system is used to generate 18 realistic, time varying simulations of propeller aircraft takeoff noise in which the harmonic content is systematically varied to represent the factorial combinations of six fundamental frequencies ranging from 67.5 Hz to 292.5 Hz and three tone-to-broadband noise ratios of 0, 15, and 30 dB. These advanced turboprop simulations along with recordings of five conventional turboprop takeoffs and five conventional jet takeoffs are presented at D-weighted sound pressure levels of 70, 80, and 90 dB to 32 subjects in an anechoic chamber. Analyses of the subjects' annoyance judgments compare the three categories of aircraft and examine the effects of the differences in harmonic content among the advanced turboprop noises. The annoyance prediction ability of various noise measurement procedures and corrections is also examined.

  8. Comparison of advanced turboprop and conventional jet and propeller aircraft flyover noise annoyance - Preliminary results

    NASA Technical Reports Server (NTRS)

    Mccurdy, D. A.

    1985-01-01

    A laboratory experiment was conducted to compare the flyover noise annoyance of proposed advanced turboprop aircraft with that of conventional turboprop and jet aircraft. The effects of fundamental frequency and tone-to-broadband noise ratio on advanced turboprop annoyance were also examined. A computer synthesis system was used to generate 18 realistic, time varyring simulations of propeller aircraft takeoff noise in which the harmonic content was systematically varied to represent the factorial combinations of six fundamental frequencies ranging from 67.5 Hz to 292.5 Hz and three tone-to-broadband noise ratios of 0, 15, and 30 dB. These advanced turboprop simulations along with recordings of five conventional turboprop takeoffs and five conventional jet takeoffs were presented at D-weighted sound pressure levels of 70, 80, and 90 dB to 32 subjects in an anechoic chamber. Analyses of the subjects' annoyance judgments compare the three categories of aircraft and examine the effects of the differences in harmonic content among the advanced turboprop noises. The annoyance prediction ability of various noise measurement procedures and corrections is also examined.

  9. Turboprop Cargo Aircraft Systems study, phase 1

    NASA Technical Reports Server (NTRS)

    Muehlbauer, J. C.; Hewell, J. G., Jr.; Lindenbaum, S. P.; Randall, C. C.; Searle, N.; Stone, F. R., Jr.

    1980-01-01

    The effects of advanced propellers (propfan) on aircraft direct operating costs, fuel consumption, and noiseprints were determined. A comparison of three aircraft selected from the results with competitive turbofan aircraft shows that advanced turboprop aircraft offer these potential benefits, relative to advanced turbofan aircraft: 21 percent fuel saving, 26 percent higher fuel efficiency, 15 percent lower DOCs, and 25 percent shorter field lengths. Fuel consumption for the turboprop is nearly 40 percent less than for current commercial turbofan aircraft. Aircraft with both types of propulsion satisfy current federal noise regulations. Advanced turboprop aircraft have smaller noiseprints at 90 EPNdB than advanced turbofan aircraft, but large noiseprints at 70 and 80 EPNdB levels, which are usually suggested as quietness goals. Accelerated development of advanced turboprops is strongly recommended to permit early attainment of the potential fuel saving. Several areas of work are identified which may produce quieter turboprop aircraft.

  10. Annoyance caused by advanced turboprop aircraft flyover noise: Counter-rotating-propeller configuration

    NASA Technical Reports Server (NTRS)

    Mccurdy, David A.

    1990-01-01

    Two experiments were conducted to quantify the annoyance of people to flyover noise of advanced turboprop aircraft with counter rotating propellers. The first experiment examined configurations having an equal number of blades on each rotor and the second experiment examined configurations having an unequal number of blades on each rotor. The objectives were to determine the effects on annoyance of various tonal characteristics, and to compare annoyance to advanced turboprops with annoyance to conventional turboprops and turbofans. A computer was used to synthesize realistic, time-varying simulations of advanced turboprop aircraft takeoff noise. The simulations represented different combinations fundamental frequency and tone-to-broadband noise ratio. Also included in each experiment were recordings of 10 conventional turboprop and turbofan takeoffs. Each noise was presented at three sound pressure levels in an anechoic chamber. In each experiment, 64 subjects judged the annoyance of each noise stimulus. Analyses indicated that annoyance was significantly affected by the interaction of fundamental frequency with tone-to-broadband noise ratio. No significant differences in annoyance between the advanced turboprop aircraft and the conventional turbofans were found. The use of a duration correction and a modified tone correction improved the annoyance prediction for the stimuli.

  11. Analysis of interior noise ground and flight test data for advanced turboprop aircraft applications

    NASA Technical Reports Server (NTRS)

    Simpson, M. A.; Tran, B. N.

    1991-01-01

    Interior noise ground tests conducted on a DC-9 aircraft test section are described. The objectives were to study ground test and analysis techniques for evaluating the effectiveness of interior noise control treatments for advanced turboprop aircraft, and to study the sensitivity of the ground test results to changes in various test conditions. Noise and vibration measurements were conducted under simulated advanced turboprop excitation, for two interior noise control treatment configurations. These ground measurement results were compared with results of earlier UHB (Ultra High Bypass) Demonstrator flight tests with comparable interior treatment configurations. The Demonstrator is an MD-80 test aircraft with the left JT8D engine replaced with a prototype UHB advanced turboprop engine.

  12. 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.

  13. 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.

  14. Turboprop cargo aircraft systems study

    NASA Technical Reports Server (NTRS)

    Muehlbauer, J. C.; Hewell, J. G., Jr.; Lindenbaum, S. P.; Randall, C. C.; Searle, N.; Stone, R. G., Jr.

    1981-01-01

    The effects of using advanced turboprop propulsion systems to reduce the fuel consumption and direct operating costs of cargo aircraft were studied, and the impact of these systems on aircraft noise and noise prints around a terminal area was determined. Parametric variations of aircraft and propeller characteristics were investigated to determine their effects on noiseprint areas, fuel consumption, and direct operating costs. From these results, three aircraft designs were selected and subjected to design refinements and sensitivity analyses. Three competitive turbofan aircraft were also defined from parametric studies to provide a basis for comparing the two types of propulsion.

  15. Fuel conservation merits of advanced turboprop transport aircraft

    NASA Technical Reports Server (NTRS)

    Revell, J. D.; Tullis, R. H.

    1977-01-01

    The advantages of a propfan powered aircraft for the commercial air transportation system were assessed by the comparison with an equivalent turbofan transport. Comparisons were accomplished on the basis of fuel utilization and operating costs, as well as aircraft weight and size. Advantages of the propfan aircraft, concerning fuel utilization and operating costs, were accomplished by considering: (1) incorporation of propfan performance and acoustic data; (2) revised mission profiles (longer design range and reduction in; and cruise speed) (3) utilization of alternate and advanced technology engines.

  16. Preliminary study of advanced turboprop and turboshaft engines for light aircraft. [cost effectiveness

    NASA Technical Reports Server (NTRS)

    Knip, G.; Plencner, R. M.; Eisenberg, J. D.

    1980-01-01

    The effects of engine configuration, advanced component technology, compressor pressure ratio and turbine rotor-inlet temperature on such figures of merit as vehicle gross weight, mission fuel, aircraft acquisition cost, operating, cost and life cycle cost are determined for three fixed- and two rotary-wing aircraft. Compared with a current production turboprop, an advanced technology (1988) engine results in a 23 percent decrease in specific fuel consumption. Depending on the figure of merit and the mission, turbine engine cost reductions required to achieve aircraft cost parity with a current spark ignition reciprocating (SIR) engine vary from 0 to 60 percent and from 6 to 74 percent with a hypothetical advanced SIR engine. Compared with a hypothetical turboshaft using currently available technology (1978), an advanced technology (1988) engine installed in a light twin-engine helicopter results in a 16 percent reduction in mission fuel and about 11 percent in most of the other figures of merit.

  17. Application of advanced high speed turboprop technology to future civil short-haul transport aircraft design

    NASA Technical Reports Server (NTRS)

    Conlon, J. A.; Bowles, J. V.

    1978-01-01

    With an overall goal of defining the needs and requirements for short-haul transport aircraft research and development, the objective of this paper is to determine the performance and noise impact of short-haul transport aircraft designed with an advanced turboprop propulsion system. This propulsion system features high-speed propellers that have more blades and reduced diameters. Aircraft are designed for short and medium field lengths; mission block fuel and direct operating costs (DOC) are used as performance measures. The propeller diameter was optimized to minimize DOC. Two methods are employed to estimate the weight of the acoustic treatment needed to reduce interior noise to an acceptable level. Results show decreasing gross weight, block fuel, DOC, engine size, and optimum propfan diameter with increasing field length. The choice of acoustic treatment method has a significant effect on the aircraft design.

  18. Annoyance response to simulated advanced turboprop aircraft interior noise containing tonal beats

    NASA Technical Reports Server (NTRS)

    Leatherwood, Jack D.

    1987-01-01

    A study is done to investigate the effects on subjective annoyance of simulated advanced turboprop (ATP) interior noise environments containing tonal beats. The simulated environments consisted of low-frequency tones superimposed on a turbulent-boundary-layer noise spectrum. The variables used in the study included propeller tone frequency (100 to 250 Hz), propeller tone levels (84 to 105 dB), and tonal beat frequency (0 to 1.0 Hz). Results indicated that propeller tones within the simulated ATP environment resulted in increased annoyance response that was fully predictable in terms of the increase in overall sound pressure level due to the tones. Implications for ATP aircraft include the following: (1) the interior noise environment with propeller tones is more annoying than an environment without tones if the tone is present at a level sufficient to increase the overall sound pressure level; (2) the increased annoyance due to the fundamental propeller tone frequency without harmonics is predictable from the overall sound pressure level; and (3) no additional noise penalty due to the perception of single discrete-frequency tones and/or beats was observed.

  19. Advanced turboprop vibratory characteristics

    NASA Technical Reports Server (NTRS)

    Srinivasan, A. V.; Fulton, G. B.

    1984-01-01

    The assembly of SR5 advanced turboprop blades to develop a structural dynamic data base for swept props is reported. Steady state blade deformation under centrifugal loading and vibratory characteristics of the rotor assembly were measured. Vibration was induced through a system of piezoelectric crystals attached to the blades. Data reduction procedures are used to provide deformation, mode shape, and frequencies of the assembly at predetermined speeds.

  20. En route noise of two turboprop aircraft

    NASA Technical Reports Server (NTRS)

    Dobrzynski, Werner

    1990-01-01

    In order to weigh en route noise emissions originating from future propfan powered aircraft, a data base of emission levels from conventional turboprop aircraft is needed. For this reason flyover noise measurements on two twin-engine turboprop aircraft were conducted at flight heights between 17,000 and 21,000 ft. Acoustic data are presented together with propeller operational parameters and environmental meteorological data. Narrowband spectral analyses demonstrate the characteristic features of the measured propeller noise signatures: Noise spectra are dominated by the propeller rotational noise fundamental frequency and pronounced noise beats occur as a consequence of different rotational speeds of the propellers.

  1. Advanced turboprop technology development

    NASA Technical Reports Server (NTRS)

    Dugan, J. F.; Bencze, D. P.; Williams, L. J.

    1977-01-01

    The efficiency of high-speed turboprop propulsion systems is considered with emphasis on fuel savings. Specific topics discussed include: (1) high efficiency and low noise of propeller design; (2) fuselage noise attenuation; (3) propeller and gear box maintenance; and (4) engine-airframe integration.

  2. Turboprop aircraft against terrorism: a SWOT analysis of turboprop aircraft in CAS operations

    NASA Astrophysics Data System (ADS)

    Yavuz, Murat; Akkas, Ali; Aslan, Yavuz

    2012-06-01

    Today, the threat perception is changing. Not only for countries but also for defence organisations like NATO, new threat perception is pointing terrorism. Many countries' air forces become responsible of fighting against terorism or Counter-Insurgency (COIN) Operations. Different from conventional warfare, alternative weapon or weapon systems are required for such operatioins. In counter-terrorism operations modern fighter jets are used as well as helicopters, subsonic jets, Unmanned Aircraft Systems (UAS), turboprop aircraft, baloons and similar platforms. Succes and efficiency of the use of these platforms can be determined by evaluating the conditions, the threats and the area together. Obviously, each platform has advantages and disadvantages for different cases. In this research, examples of turboprop aircraft usage against terrorism and with a more general approach, turboprop aircraft for Close Air Support (CAS) missions from all around the world are reviewed. In this effort, a closer look is taken at the countries using turboprop aircraft in CAS missions while observing the fields these aircraft are used in, type of operations, specifications of the aircraft, cost and the maintenance factors. Thus, an idea about the convenience of using these aircraft in such operations can be obtained. A SWOT analysis of turboprop aircraft in CAS operations is performed. This study shows that turboprop aircraft are suitable to be used in counter-terrorism and COIN operations in low threat environment and is cost benefical compared to jets.

  3. Low-speed wind-tunnel investigation of the flight dynamic characteristics of an advanced turboprop business/commuter aircraft configuration

    NASA Technical Reports Server (NTRS)

    Coe, Paul L., Jr.; Turner, Steven G.; Owens, D. Bruce

    1990-01-01

    An investigation was conducted to determine the low-speed flight dynamic behavior of a representative advanced turboprop business/commuter aircraft concept. Free-flight tests were conducted in the NASA Langley Research Center's 30- by 60-Foot Tunnel. In support of the free-flight tests, conventional static, dynamic, and free-to-roll oscillation tests were performed. Tests were intended to explore normal operating and post stall flight conditions, and conditions simulating the loss of power in one engine.

  4. NASA/industry advanced turboprop technology program

    NASA Technical Reports Server (NTRS)

    Ziemianski, Joseph A.; Whitlow, John B., Jr.

    1988-01-01

    Experimental and analytical effort shows that use of advanced turboprop (propfan) propulsion instead of conventional turbofans in the older narrow-body airline fleet could reduce fuel consumption for this type of aircraft by up to 50 percent. The NASA Advanced Turboprop (ATP) program was formulated to address the key technologies required for these thin, swept-blade propeller concepts. A NASA, industry, and university team was assembled to develop and validate applicable design codes and prove by ground and flight test the viability of these propeller concepts. Some of the history of the ATP Project, an overview of some of the issues, and a summary of the technology developed to make advanced propellers viable in the high-subsonic cruise speed application are presented. The ATP program was awarded the prestigious Robert J. Collier Trophy for the greatest achievement in aeronautics and astronautics in America in 1987.

  5. NASA/industry advanced turboprop technology program

    NASA Technical Reports Server (NTRS)

    Ziemianski, Joseph A.; Whitlow, John B., Jr.

    1988-01-01

    Experimental and analytical effort shows that use of advanced turboprop (propfan) propulsion instead of conventional turbofans in the older narrow-body airline fleet could reduce fuel consumption for this type of aircraft by up to 50 percent. The NASA Advanced Turboprop (ATP) program was formulated to address the key technologies required for these thin, swept-blade propeller concepts. A NASA, industry, and university team was assembled to develop and validate applicable design codes and prove by ground and flight test the viability of these propeller concepts. Some of the history of the ATP project, an overview of some of the issues, and a summary of the technology developed to make advanced propellers viable in the high-subsonic cruise speed application are presented. The ATP program was awarded the prestigious Robert J. Collier Trophy for the greatest achievement in aeronautics and astronautics in America in 1987.

  6. NASA advanced turboprop research and concept validation program

    NASA Technical Reports Server (NTRS)

    Whitlow, John B., Jr.; Sievers, G. Keith

    1988-01-01

    NASA has determined by experimental and analytical effort that use of advanced turboprop propulsion instead of the conventional turbofans in the older narrow-body airline fleet could reduce fuel consumption for this type of aircraft by up to 50 percent. In cooperation with industry, NASA has defined and implemented an Advanced Turboprop (ATP) program to develop and validate the technology required for these new high-speed, multibladed, thin, swept propeller concepts. This paper presents an overview of the analysis, model-scale test, and large-scale flight test elements of the program together with preliminary test results, as available.

  7. Advanced turboprop testbed systems study

    NASA Technical Reports Server (NTRS)

    Goldsmith, I. M.

    1982-01-01

    The proof of concept, feasibility, and verification of the advanced prop fan and of the integrated advanced prop fan aircraft are established. The use of existing hardware is compatible with having a successfully expedited testbed ready for flight. A prop fan testbed aircraft is definitely feasible and necessary for verification of prop fan/prop fan aircraft integrity. The Allison T701 is most suitable as a propulsor and modification of existing engine and propeller controls are adequate for the testbed. The airframer is considered the logical overall systems integrator of the testbed program.

  8. 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.

  9. Structural Tailoring of Advanced Turboprops (STAT)

    NASA Technical Reports Server (NTRS)

    Brown, Kenneth W.

    1988-01-01

    This interim report describes the progress achieved in the structural Tailoring of Advanced Turboprops (STAT) program which was developed to perform numerical optimizations on highly swept propfan blades. The optimization procedure seeks to minimize an objective function, defined as either direct operating cost or aeroelastic differences between a blade and its scaled model, by tuning internal and external geometry variables that must satisfy realistic blade design constraints. This report provides a detailed description of the input, optimization procedures, approximate analyses and refined analyses, as well as validation test cases for the STAT program. In addition, conclusions and recommendations are summarized.

  10. Quelling Cabin Noise in Turboprop Aircraft via Active Control

    NASA Technical Reports Server (NTRS)

    Kincaid, Rex K.; Laba, Keith E.; Padula, Sharon L.

    1997-01-01

    Cabin noise in turboprop aircraft causes passenger discomfort, airframe fatigue, and employee scheduling constraints due to OSHA standards for exposure to high levels of noise. The noise levels in the cabins of turboprop aircraft are typically 10 to 30 decibels louder than commercial jet noise levels. However. unlike jet noise the turboprop noise spectrum is dominated by a few low frequency tones. Active structural acoustic control is a method in which the control inputs (used to reduce interior noise) are applied directly to a vibrating structural acoustic system. The control concept modeled in this work is the application of in-plane force inputs to piezoceramic patches bonded to the wall of a vibrating cylinder. The goal is to determine the force inputs and locations for the piezoceramic actuators so that: (1) the interior noise is effectively damped; (2) the level of vibration of the cylinder shell is not increased; and (3) the power requirements needed to drive the actuators are not excessive. Computational experiments for data taken from a computer generated model and from a laboratory test article at NASA Langley Research Center are provided.

  11. Structural tailoring of advanced turboprops (STAT): User's manual

    NASA Technical Reports Server (NTRS)

    Brown, K. W.

    1991-01-01

    This user's manual describes the Structural Tailoring of Advanced Turboprops program. It contains instructions to prepare the input for optimization, blade geometry and analysis, geometry generation, and finite element program control. In addition, a sample input file is provided as well as a section describing special applications (i.e., non-standard input).

  12. Piloted simulation study of an ILS approach of a twin-pusher business/commuter turboprop aircraft configuration

    NASA Technical Reports Server (NTRS)

    Riley, Donald R.; Brandon, Jay M.; Glaab, Louis J.

    1994-01-01

    A six-degree-of-freedom nonlinear simulation of a twin-pusher, turboprop business/commuter aircraft configuration representative of the Cessna ATPTB (Advanced turboprop test bed) was developed for use in piloted studies with the Langley General Aviation Simulator. The math models developed are provided, simulation predictions are compared with with Cessna flight-test data for validation purposes, and results of a handling quality study during simulated ILS (instrument landing system) approaches and missed approaches are presented. Simulated flight trajectories, task performance measures, and pilot evaluations are presented for the ILS approach and missed-approach tasks conducted with the vehicle in the presence of moderate turbulence, varying horizontal winds and engine-out conditions. Six test subjects consisting of two research pilots, a Cessna test pilot, and three general aviation pilots participated in the study. This effort was undertaken in cooperation with the Cessna Aircraft Company.

  13. Structural Tailoring of Advanced Turboprops (STAT) programmer's manual

    NASA Technical Reports Server (NTRS)

    Brown, K. W.; Harvey, P. R.

    1989-01-01

    The Structural Tailoring of Advanced Turboprops (STAT) computer program was developed to perform numerical optimizations on highly swept propfan blades. This manual describes the functionality of the STAT system from a programmer's viewpoint. It provides a top-down description of module intent and interaction. The purpose of this manual is to familiarize the programmer with the STAT system should he/she wish to enhance or verify the program's function.

  14. Advanced turboprop testbed systems study. Volume 1: Testbed program objectives and priorities, drive system and aircraft design studies, evaluation and recommendations and wind tunnel test plans

    NASA Technical Reports Server (NTRS)

    Bradley, E. S.; Little, B. H.; Warnock, W.; Jenness, C. M.; Wilson, J. M.; Powell, C. W.; Shoaf, L.

    1982-01-01

    The establishment of propfan technology readiness was determined and candidate drive systems for propfan application were identified. Candidate testbed aircraft were investigated for testbed aircraft suitability and four aircraft selected as possible propfan testbed vehicles. An evaluation of the four candidates was performed and the Boeing KC-135A and the Gulfstream American Gulfstream II recommended as the most suitable aircraft for test application. Conceptual designs of the two recommended aircraft were performed and cost and schedule data for the entire testbed program were generated. The program total cost was estimated and a wind tunnel program cost and schedule is generated in support of the testbed program.

  15. Return of the turboprops

    SciTech Connect

    Facey, J.R.; Whitlow, J.B. Jr.; Sievers, G.K.; Groeneweg, J.; Shepherd, K.; Henderson, W.

    1988-10-01

    Recent advances in propfan development for commercial aircraft cruising at high transonic speeds are discussed in a series of brief overviews and illustrated with photographs and diagrams. The efficiency and performance advantages and the problem of noise are examined; the history of turboprop design since the 1950s is recalled; NASA, DOT, FAA, and DOD turboprop projects are described; and the results of wind-tunnel and flight tests on particular propeller models are reviewed. Current trends in aircraft reconfiguration and acoustic redesign to reduce cabin noise levels are also surveyed.

  16. Simulation Modeling Requirements for Loss-of-Control Accident Prevention of Turboprop Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Crider, Dennis; Foster, John V.

    2012-01-01

    In-flight loss of control remains the leading contributor to aviation accident fatalities, with stall upsets being the leading causal factor. The February 12, 2009. Colgan Air, Inc., Continental Express flight 3407 accident outside Buffalo, New York, brought this issue to the forefront of public consciousness and resulted in recommendations from the National Transportation Safety Board to conduct training that incorporates stalls that are fully developed and develop simulator standards to support such training. In 2010, Congress responded to this accident with Public Law 11-216 (Section 208), which mandates full stall training for Part 121 flight operations. Efforts are currently in progress to develop recommendations on implementation of stall training for airline pilots. The International Committee on Aviation Training in Extended Envelopes (ICATEE) is currently defining simulator fidelity standards that will be necessary for effective stall training. These recommendations will apply to all civil transport aircraft including straight-wing turboprop aircraft. Government-funded research over the previous decade provides a strong foundation for stall/post-stall simulation for swept-wing, conventional tail jets to respond to this mandate, but turboprops present additional and unique modeling challenges. First among these challenges is the effect of power, which can provide enhanced flow attachment behind the propellers. Furthermore, turboprops tend to operate for longer periods in an environment more susceptible to ice. As a result, there have been a significant number of turboprop accidents as a result of the early (lower angle of attack) stalls in icing. The vulnerability of turboprop configurations to icing has led to studies on ice accumulation and the resulting effects on flight behavior. Piloted simulations of these effects have highlighted the important training needs for recognition and mitigation of icing effects, including the reduction of stall margins

  17. Acoustic test and analyses of three advanced turboprop models

    NASA Technical Reports Server (NTRS)

    Brooks, B. M.; Metzger, F. B.

    1980-01-01

    Results of acoustic tests of three 62.2 cm (24.5 inch) diameter models of the prop-fan (a small diameter, highly loaded. Multi-bladed variable pitch advanced turboprop) are presented. Results show that there is little difference in the noise produced by unswept and slightly swept designs. However, the model designed for noise reduction produces substantially less noise at test conditions simulating 0.8 Mach number cruise speed or at conditions simulating takeoff and landing. In the near field at cruise conditions the acoustically designed. In the far field at takeoff and landing conditions the acoustically designed model is 5 db quieter than unswept or slightly swept designs. Correlation between noise measurement and theoretical predictions as well as comparisons between measured and predicted acoustic pressure pulses generated by the prop-fan blades are discussed. The general characteristics of the pulses are predicted. Shadowgraph measurements were obtained which showed the location of bow and trailing waves.

  18. Bending-torsion flutter of a highly swept advanced turboprop

    NASA Technical Reports Server (NTRS)

    Mehmed, O.; Kaza, K. R. V.; Lubomski, J. F.; Kielb, R. E.

    1981-01-01

    Experimental and analytical results are presented for a bending-torsion flutter phenomena encountered during wind-tunnel testing of a ten-bladed, advanced, high-speed propeller (turboprop) model with thin airfoil sections, high blade sweep, low aspect ratio, high solidity and transonic tip speeds. Flutter occurred at free-stream Mach numbers of 0.6 and greater and when the relative tip Mach number (based on vector sum of axial and tangential velocities) reached a value of about one. The experiment also included two- and five-blade configurations. The data indicate that aerodynamic cascade effects have a strong destabilizing influence on the flutter boundary. The data was correlated with analytical results which include aerodynamic cascade effects and good agreement was found.

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

    NASA Astrophysics Data System (ADS)

    Atilgan, Ramazan; Turan, Onder; Aydin, Hakan

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

  20. Flight investigation of cabin noise control treatments for a light turboprop aircraft

    NASA Technical Reports Server (NTRS)

    Wilby, J. F.; Oneal, R. L.; Mixson, J. S.

    1985-01-01

    The in-flight evaluation of noise control treatments for a light, twin-engined turboprop aircraft presents several problems associated with data analysis and interpretation. These problems include data repeatability, propeller synchronization, spatial distributions of the exterior pressure field and acoustic treatment, and the presence of flanking paths. They are discussed here with regard to a specific aeroplane configuration. Measurements were made in an untreated cabin and in a cabin fitted with an experimental sidewall treatment. Results are presented in terms of the insertion loss provided by the treatment and comparison made with predictions based on laboratory measurements.

  1. Structural Tailoring of Advanced Turboprops (STAT). Theoretical manual

    NASA Technical Reports Server (NTRS)

    Brown, K. W.

    1992-01-01

    This manual describes the theories in the Structural Tailoring of Advanced Turboprops (STAT) computer program, which was developed to perform numerical optimizations on highly swept propfan blades. The optimization procedure seeks to minimize an objective function, defined as either direct operating cost or aeroelastic differences between a blade and its scaled model, by tuning internal and external geometry variables that must satisfy realistic blade design constraints. The STAT analyses include an aerodynamic efficiency evaluation, a finite element stress and vibration analysis, an acoustic analysis, a flutter analysis, and a once-per-revolution (1-p) forced response life prediction capability. The STAT constraints include blade stresses, blade resonances, flutter, tip displacements, and a 1-P forced response life fraction. The STAT variables include all blade internal and external geometry parameters needed to define a composite material blade. The STAT objective function is dependent upon a blade baseline definition which the user supplies to describe a current blade design for cost optimization or for the tailoring of an aeroelastic scale model.

  2. Experimental Classical Flutter Reesults of a Composite Advanced Turboprop Model

    NASA Technical Reports Server (NTRS)

    Mehmed, O.; Kaza, K. R. V.

    1986-01-01

    Experimental results are presented that show the effects of blade pitch angle and number of blades on classical flutter of a composite advanced turboprop (propfan) model. An increase in the number of blades on the rotor or the blade pitch angle is destablizing which shows an aerodynamic coupling or cascade effect between blades. The flutter came in suddenly and all blades vibrated at the same frequency but at different amplitudes and with a common predominant phase angle between consecutive blades. This further indicates aerodynamic coupling between blades. The flutter frequency was between the first two blade normal modes, signifying an aerodynamic coupling between the normal modes. Flutter was observed at all blade pitch angles from small to large angles-of-attack of the blades. A strong blade response occurred, for four blades at the two-per-revolution (2P) frequency, when the rotor speed was near the crossing of the flutter mode frequency and the 2P order line. This is because the damping is low near the flutter condition and the interblade phase angle of the flutter mode and the 2P response are the same.

  3. Fundamental studies of structure borne noise for advanced turboprop applications

    NASA Technical Reports Server (NTRS)

    Eversman, W.; Koval, L. R.

    1985-01-01

    The transmission of sound generated by wing-mounted, advanced turboprop engines into the cabin interior via structural paths is considered. The structural model employed is a beam representation of the wing box carried into the fuselage via a representative frame type of carry through structure. The structure for the cabin cavity is a stiffened shell of rectangular or cylindrical geometry. The structure is modelled using a finite element formulation and the acoustic cavity is modelled using an analytical representation appropriate for the geometry. The structural and acoustic models are coupled by the use of hard wall cavity modes for the interior and vacuum structural modes for the shell. The coupling is accomplished using a combination of analytical and finite element models. The advantage is the substantial reduction in dimensionality achieved by modelling the interior analytically. The mathematical model for the interior noise problem is demonstrated with a simple plate/cavity system which has all of the features of the fuselage interior noise problem.

  4. Analysis and test evaluation of the dynamic response and stability of three advanced turboprop models

    NASA Technical Reports Server (NTRS)

    Bansal, P. N.; Arseneaux, P. J.; Smith, A. F.; Turnberg, J. E.; Brooks, B. M.

    1985-01-01

    Results of dynamic response and stability wind tunnel tests of three 62.2 cm (24.5 in) diameter models of the Prop-Fan, advanced turboprop, are presented. Measurements of dynamic response were made with the rotors mounted on an isolated nacelle, with varying tilt for nonuniform inflow. One model was also tested using a semi-span wing and fuselage configuration for response to realistic aircraft inflow. Stability tests were performed using tunnel turbulence or a nitrogen jet for excitation. Measurements are compared with predictions made using beam analysis methods for the model with straight blades, and finite element analysis methods for the models with swept blades. Correlations between measured and predicted rotating blade natural frequencies for all the models are very good. The IP dynamic response of the straight blade model is reasonably well predicted. The IP response of the swept blades is underpredicted and the wing induced response of the straight blade is overpredicted. Two models did not flutter, as predicted. One swept blade model encountered an instability at a higher RPM than predicted, showing predictions to be conservative.

  5. Advanced turbo-prop airplane interior noise reduction-source definition

    NASA Technical Reports Server (NTRS)

    Magliozzi, B.; Brooks, B. M.

    1979-01-01

    Acoustic pressure amplitudes and phases were measured in model scale on the surface of a rigid semicylinder mounted in an acoustically treated wind tunnel near a prop-fan (an advanced turboprop with many swept blades) model. Operating conditions during the test simulated those of a prop-fan at 0.8 Mach number cruise. Acoustic pressure amplitude and phase contours were defined on the semicylinder surface. Measurements obtained without the semi-cylinder in place were used to establish the magnitude of pressure doubling for an aircraft fuselage located near a prop-fan. Pressure doubling effects were found to be 6dB at 90 deg incidence decreasing to no effect at grazing incidence. Comparisons of measurements with predictions made using a recently developed prop-fan noise prediction theory which includes linear and non-linear source terms showed good agreement in phase and in peak noise amplitude. Predictions of noise amplitude and phase contours, including pressure doubling effects derived from test, are included for a full scale prop-fan installation.

  6. Application of advanced technologies to small, short-haul transport aircraft

    NASA Technical Reports Server (NTRS)

    Coussens, T. G.; Tullis, R. H.

    1980-01-01

    The performance and economic benefits available by incorporation of advanced technologies into the small, short haul air transport were assessed. Low cost structure and advanced composite material, advanced turboprop engines and new propellers, advanced high lift systems and active controls; and alternate aircraft configurations with aft mounted engines were investigated. Improvements in fuel consumed and aircraft economics (acquisition cost and direct operating cost) are available by incorporating selected advanced technologies into the small, short haul aircraft.

  7. Low-speed stability and control characteristics of a transport model with aft-fuselage-mounted advanced turboprops

    NASA Technical Reports Server (NTRS)

    Applin, Z. T.; Coe, P. L., Jr.

    1986-01-01

    A limited experimental investigation was conducted in the Langley 4- by 7-Meter Tunnel to explore the effects of aft-fuselage-mounted advanced turboprop installations on the low-speed stability and control characteristics of a representative transport aircraft in a landing configuration. In general, the experimental results indicate that the longitudinal and lateral-directional stability characteristics for the aft-fuselage-mounted single-rotation tractor and counter-rotation pusher propeller configurations tested during this investigation are acceptable aerodynamically. For the single-rotation tractor configuration, the propeller-induced aerodynamics are significantly influenced by the interaction of the propeller slipstream with the pylon and nacelle. The stability characteristics for the counter-rotation pusher configuration are strongly influenced by propeller normal forces. The longitudinal and directional control effectiveness, engine-out characteristics, and ground effects are also presented. In addition, a tabulated presentation of all aerodynamic data presented in this report is included as an appendix.

  8. 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.

  9. Analysis of results from wind tunnel tests of inlets for an advanced turboprop nacelle installation

    NASA Technical Reports Server (NTRS)

    Hancock, J. P.; Lyman, V.; Pennock, A. P.

    1986-01-01

    Inlets for tractor installations of advanced turboprop propulsion systems were tested in three phases, covering a period from November, 1982 to January, 1984. Nacelle inlet configuration types included single scoop, twin scoop, and annular arrangements. Tests were performed with and without boundary layer diverters and several different diverter heights were tested for the single scoop inlet. This same inlet was also tested at two different axial positions. Test Mach numbers ranged from Mach 0.20 to 0.80. Types of data taken were: (1) internal and external pressures, including inlet throat recoveries; (2) balance forces, including thrust-minus-drag; and (3) propellar blade stresses.

  10. Study on Design of High Efficiency and Light Weight Composite Propeller Blade for a Regional Turboprop Aircraft

    NASA Astrophysics Data System (ADS)

    Kong, Changduk; Lee, Kyungsun

    2013-03-01

    In this study, aerodynamic and structural design of the composite propeller blade for a regional turboprop aircraft is performed. The thin and wide chord propeller blade of high speed turboprop aircraft should have proper strength and stiffness to carry various kinds of loads such as high aerodynamic bending and twisting moments and centrifugal forces. Therefore the skin-spar-foam sandwich structure using high strength and stiffness carbon/epoxy composite materials is used to improve the lightness. A specific design procedure is proposed in this work as follows; firstly the aerodynamic configuration design, which is acceptable for the design requirements, is carried out using the in-house code developed by authors, secondly the structure design loads are determined through the aerodynamic load case analysis, thirdly the spar flange and the skin are preliminarily sized by consideration of major bending moments and shear forces using both the netting rule and the rule of mixture, and finally, the stress analysis is performed to confirm the structural safety and stability using finite element analysis commercial code, MSC. NASTRAN/PATRAN. Furthermore the additional analysis is performed to confirm the structural safety due to bird strike impact on the blade during flight operation using a commercial code, ANSYS. To realize the proposed propeller design, the prototype blades are manufactured by the following procedure; the carbon/epoxy composite fabric prepregs are laid up for skin and spar on a mold using the hand lay-up method and consolidated with a proper temperature and vacuum in the oven. To finalize the structural design, the full-scale static structural test is performed under the simulated aerodynamic loads using 3 point loading method. From the experimental results, it is found that the designed blade has a good structural integrity, and the measured results agree well with the analytical results as well.

  11. Turboprop Propulsion Mechanic.

    ERIC Educational Resources Information Center

    Chanute AFB Technical Training Center, IL.

    This instructional package consists of a plan of instruction, glossary, and student handouts and exercises for use in training Air Force personnel to become turboprop propulsion mechanics. Addressed in the individual lessons of the course are the following: common hand tools, hardware, measuring devices, and safety wiring; aircraft and engine…

  12. Parametric study of factors affecting the fuel efficiency of advanced turboprop airplanes

    NASA Technical Reports Server (NTRS)

    Johnson, V. S.

    1983-01-01

    Results of a parametric study to determine the effects of design variables and penalties on the fuel efficiency of Mach 0.8, 125-passenger, advanced turboprop airplanes show that propeller-wing interference penalty has a major effect. Propeller tip speed has a minor effect, and could be decreased to alleviate the noise problem without significant effects on fuel efficiency. The anticipated noise levels produced by the propfan will require additional acoustical treatment for the fuselage; this additional weight can have a significant effect on fuel efficiency. The propfan advantage over an equivalent technology turbofan is strongly dependent on the interference penalty and acoustical treatment weight. Lowering the cruise Mach number to around 0.73 would result in greatly increased fuel efficiency.

  13. Laser-velocimeter flow-field measurements of an advanced turboprop

    NASA Technical Reports Server (NTRS)

    Serafini, J. S.; Sullivan, J. P.; Neumann, H. E.

    1981-01-01

    Non-intrusive measurements of velocity about a spinner-propeller-nacelle configuration at a Mach number of 0.8 were performed. A laser velocimeter, specifically developed for these measurements in the NASA Lewis 8-foot by 6-foot Supersonic Wind Tunnel, was used to measure the flow-field of the advanced swept SR-3 turboprop. The laser velocimeter uses an argon ion laser and a 2-color optics system to allow simultaneous measurements of 2-components of velocity. The axisymmetric nature of the propeller-nacelle flow-field permits two separate 2 dimensonal measurements to be combined into 3 dimensional velocity data. Presented are data ahead of and behind the prop blades and also a limited set in between the blades. Aspects of the observed flow-field such as the tip vortex are discussed.

  14. The Langley turbo-prop commuter design: A complete project description

    NASA Technical Reports Server (NTRS)

    Buttram, Greg; Horton, Keith; Keeter, Tim; Millhouse, Paul; Newberry, Kelli; Obyrne, Brian

    1991-01-01

    The primary objective of this project was to propose and prove the possibility of a new, advanced technology commuter aircraft design. Among the specifications were short to medium range capabilities, low seat per mile cost, fuel efficiency, and passenger comfort. Based on market evaluation, we found that the optimum size for new regional aircraft is around 50 passengers; we have designed our aircraft for this capacity. Turboprop engines provide substantial reductions in operating costs due to lower fuel consumption. We have therefore chosen an advanced turboprop engine. Composite materials, while more expensive to purchase and manufacture, result in decreased costs later through weight savings and ease of replacement.

  15. Comparison ofdvanced turboprop interior noise control ground and flight test data

    NASA Technical Reports Server (NTRS)

    Simpson, Myles A.; Tran, Boi N.

    1992-01-01

    Interior noise ground tests conducted on a DC-9 aircraft test section are described. The objectives were to study ground test and analysis techniques for evaluating the effectiveness of interior noise control treatments for advanced turboprop aircraft, and to study the sensitivity of the ground test results to changes in various test conditions. Noise and vibration measurements were conducted under simulated advanced turboprop excitation, for two interior noise control treatment configurations. These ground measurement results were compared with results of earlier UHB (Ultra High Bypass) Demonstrator flight sts with comparable interior treatment configurations. The Demonstrator is an MD-80 test aircraft with the left JT8D engine replaced with a prototype UHB advanced turboprop engine.

  16. 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.

  17. 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.

  18. En route noise of turboprop aircraft and their acceptability: Report of tests

    NASA Technical Reports Server (NTRS)

    Held, Wolf

    1990-01-01

    The development of propfan-powered aircraft has been observed with great interest. It is obvious that during cruising flight, the aircraft powerplant (propellers) cause a noise clearly perceivable on the ground. It is the audible frequency spectrum of the propfan powerplants relative to the high tip speeds that presents the problem. A flight test was conducted on 30 April, 1989 at the Frankfurt Airport. Results of the test flight are present.

  19. Application of advanced technologies to small, short-haul aircraft

    NASA Technical Reports Server (NTRS)

    Andrews, D. G.; Brubaker, P. W.; Bryant, S. L.; Clay, C. W.; Giridharadas, B.; Hamamoto, M.; Kelly, T. J.; Proctor, D. K.; Myron, C. E.; Sullivan, R. L.

    1978-01-01

    The results of a preliminary design study which investigates the use of selected advanced technologies to achieve low cost design for small (50-passenger), short haul (50 to 1000 mile) transports are reported. The largest single item in the cost of manufacturing an airplane of this type is labor. A careful examination of advanced technology to airframe structure was performed since one of the most labor-intensive parts of the airplane is structures. Also, preliminary investigation of advanced aerodynamics flight controls, ride control and gust load alleviation systems, aircraft systems and turbo-prop propulsion systems was performed. The most beneficial advanced technology examined was bonded aluminum primary structure. The use of this structure in large wing panels and body sections resulted in a greatly reduced number of parts and fasteners and therefore, labor hours. The resultant cost of assembled airplane structure was reduced by 40% and the total airplane manufacturing cost by 16% - a major cost reduction. With further development, test verification and optimization appreciable weight saving is also achievable. Other advanced technology items which showed significant gains are as follows: (1) advanced turboprop-reduced block fuel by 15.30% depending on range; (2) configuration revisions (vee-tail)-empennage cost reduction of 25%; (3) leading-edge flap addition-weight reduction of 2500 pounds.

  20. Measured far-field flight noise of a counterrotation turboprop at cruise conditions

    NASA Astrophysics Data System (ADS)

    Woodward, Richard P.; Loeffler, Irvin J.; Dittmar, James H.

    1989-01-01

    Modern high speed propeller (advanced turboprop) aircraft are expected to operate on 50 to 60 percent less fuel than the 1980 vintage turbofan fleet while at the same time matching the flight speed and performance of those aircraft. Counterrotation turboprop engines offer additional fuel savings by means of upstream propeller swirl recovery. This paper presents acoustic sideline results for a full-scale counterrotation turboprop engine at cruise conditions. The engine was installed on a Boeing 727 aircraft in place of the right-side turbofan engine. Acoustic data were taken from an instrumented Learjet chase plane. Sideline acoustic results are presented for 0.50 and 0.72 Mach cruise conditions. A scale model of the engine propeller was tested in a wind tunnel at 0.72 Mach cruise conditions. The model data were adjusted to flight acquisition conditions and were in general agreement with the flight results.

  1. User's guide to PMESH: A grid-generation program for single-rotation and counterrotation advanced turboprops

    NASA Technical Reports Server (NTRS)

    Warsi, Saif A.

    1989-01-01

    A detailed operating manual is presented for a grid generating program that produces 3-D meshes for advanced turboprops. The code uses both algebraic and elliptic partial differential equation methods to generate single rotation and counterrotation, H or C type meshes for the z - r planes and H type for the z - theta planes. The code allows easy specification of geometrical constraints (such as blade angle, location of bounding surfaces, etc.), mesh control parameters (point distribution near blades and nacelle, number of grid points desired, etc.), and it has good runtime diagnostics. An overview is provided of the mesh generation procedure, sample input dataset with detailed explanation of all input, and example meshes.

  2. Evaluation of advanced lift concepts and potential fuel conservation for short-haul aircraft

    NASA Technical Reports Server (NTRS)

    Sweet, H. S.; Renshaw, J. H.; Bowden, M. K.

    1975-01-01

    The effect of different field lengths, cruise requirements, noise level, and engine cycle characteristics on minimizing fuel consumption and minimizing operating cost at high fuel prices were evaluated for some advanced short-haul aircraft. The conceptual aircraft were designed for 148 passengers using the upper surface-internally blown jet flap, the augmentor wing, and the mechanical flap lift systems. Advanced conceptual STOL engines were evaluated as well as a near-term turbofan and turboprop engine. Emphasis was given to designs meeting noise levels equivalent to 95-100 EPNdB at 152 m (500 ft) sideline.

  3. Analysis and test evaluation of the dynamic response and stability of three advanced turboprop models at low forward speed

    NASA Technical Reports Server (NTRS)

    Smith, Arthur F.

    1985-01-01

    Results of wind tunnel tests at low forward speed for blade dynamic response and stability of three 62.2 cm (24.5 in) diameter models of the Prop-Fan, advanced turboprop, are presented. Measurements of dynamic response were made with the rotors mounted on an isolated nacelle, with varying tilt for nonuniform inflow. Low speed stall flutter tests were conducted at Mach numbers from 0.0 to 0.35. Measurements are compared to Eigen-solution flutter boundaries. Calculated 1P stress response agrees favorably with experiment. Predicted stall flutter boundaries correlate well with measured high stress regions. Stall flutter is significantly reduced by increased blade sweep. Susceptibility to stall flutter decreases rapidly with forward speed.

  4. Acoustic flight testing of advanced design propellers on a JetStar aircraft

    NASA Astrophysics Data System (ADS)

    Lasagna, P.; Mackall, K.

    1981-12-01

    Advanced turboprop-powered aircraft have the potential to reduce fuel consumption by 15 to 30 percent as compared with an equivalent technology turbofan-powered aircraft. An important obstacle to the use of advanced design propellers is the cabin noise generated at Mach numbers up to .8 and at altitudes up to 35,000 feet. As part of the NASA Aircraft Energy Efficiency Program, the near-field acoustic characteristics on a series of advanced design propellers are investigated. Currently, Dryden Flight Research Center is flight testing a series of propellers on a JetStar airplane. The propellers used in the flight test were previously tested in wind tunnels at the Lewis Research Center. Data are presented showing the narrow band spectra, acoustic wave form, and acoustic contours on the fuselage surface. Additional flights with the SR-3 propeller and other advanced propellers are planned in the future.

  5. Acoustic flight testing of advanced design propellers on a JetStar aircraft

    NASA Technical Reports Server (NTRS)

    Lasagna, P.; Mackall, K.

    1981-01-01

    Advanced turboprop-powered aircraft have the potential to reduce fuel consumption by 15 to 30 percent as compared with an equivalent technology turbofan-powered aircraft. An important obstacle to the use of advanced design propellers is the cabin noise generated at Mach numbers up to .8 and at altitudes up to 35,000 feet. As part of the NASA Aircraft Energy Efficiency Program, the near-field acoustic characteristics on a series of advanced design propellers are investigated. Currently, Dryden Flight Research Center is flight testing a series of propellers on a JetStar airplane. The propellers used in the flight test were previously tested in wind tunnels at the Lewis Research Center. Data are presented showing the narrow band spectra, acoustic wave form, and acoustic contours on the fuselage surface. Additional flights with the SR-3 propeller and other advanced propellers are planned in the future.

  6. Advanced technology composite aircraft structures

    NASA Technical Reports Server (NTRS)

    Ilcewicz, Larry B.; Walker, Thomas H.

    1991-01-01

    Work performed during the 25th month on NAS1-18889, Advanced Technology Composite Aircraft Structures, is summarized. The main objective of this program is to develop an integrated technology and demonstrate a confidence level that permits the cost- and weight-effective use of advanced composite materials in primary structures of future aircraft with the emphasis on pressurized fuselages. The period from 1-31 May 1991 is covered.

  7. Advanced hypersonic aircraft design

    NASA Technical Reports Server (NTRS)

    Utzinger, Rob; Blank, Hans-Joachim; Cox, Craig; Harvey, Greg; Mckee, Mike; Molnar, Dave; Nagy, Greg; Petersen, Steve

    1992-01-01

    The objective of this design project is to develop the hypersonic reconnaissance aircraft to replace the SR-71 and to complement existing intelligence gathering devices. The initial design considerations were to create a manned vehicle which could complete its mission with at least two airborne refuelings. The aircraft must travel between Mach 4 and Mach 7 at an altitude of 80,000 feet for a maximum range of 12,000 nautical miles. The vehicle should have an air breathing propulsion system at cruise. With a crew of two, the aircraft should be able to take off and land on a 10,000 foot runway, and the yearly operational costs were not to exceed $300 million. Finally, the aircraft should exhibit stealth characteristics, including a minimized radar cross-section (RCS) and a reduced sonic boom. The technology used in this vehicle should allow for production between the years 1993 and 1995.

  8. Low-speed wind tunnel investigation of the static stability and control characteristics of an advanced turboprop configuration with the propellers placed over the tail. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Rhodes, Graham Scott

    1990-01-01

    An exploratory wind tunnel investigation was performed in the 30 x 60 foot wind tunnel to determine the low speed static stability and control characteristics into the deep stall regime of an advanced turboprop aircraft with the propellers located over the horizontal tail. By this arrangement, the horizontal tail could potentially provide acoustic shielding to reduce the high community noise caused by the propeller blades. The current configuration was a generic turboprop model equipped with 1 foot diameter single rotating eight bladed propellers that were designed for efficient cruise operation at a Mach number of 0.8. The data presented is static force data. The effects of power on the configuration characteristics were generally favorable. An arrangement with the propellers rotating with the outboard blades moving down was found to have significantly higher installed thrust than an arrangement with the propellers rotating with the inboard blades moving down. The primary unfavorable effect was a large pitch trim change which occurred with power, but the trim change could be minimized with a proper configuration design.

  9. Turboprop and rotary-wing aircraft flight parameter estimation using both narrow-band and broadband passive acoustic signal-processing methods.

    PubMed

    Ferguson, B G; Lo, K W

    2000-10-01

    Flight parameter estimation methods for an airborne acoustic source can be divided into two categories, depending on whether the narrow-band lines or the broadband component of the received signal spectrum is processed to estimate the flight parameters. This paper provides a common framework for the formulation and test of two flight parameter estimation methods: one narrow band, the other broadband. The performances of the two methods are evaluated by applying them to the same acoustic data set, which is recorded by a planar array of passive acoustic sensors during multiple transits of a turboprop fixed-wing aircraft and two types of rotary-wing aircraft. The narrow-band method, which is based on a kinematic model that assumes the source travels in a straight line at constant speed and altitude, requires time-frequency analysis of the acoustic signal received by a single sensor during each aircraft transit. The broadband method is based on the same kinematic model, but requires observing the temporal variation of the differential time of arrival of the acoustic signal at each pair of sensors that comprises the planar array. Generalized cross correlation of each pair of sensor outputs using a cross-spectral phase transform prefilter provides instantaneous estimates of the differential times of arrival of the signal as the acoustic wavefront traverses the array.

  10. Energy efficient aircraft engines

    NASA Technical Reports Server (NTRS)

    Chamberlin, R.; Miller, B.

    1979-01-01

    The three engine programs that constitute the propulsion portion of NASA's Aircraft Energy Efficiency Program are described, their status indicated, and anticipated improvements in SFC discussed. The three engine programs are (1) Engine Component Improvement--directed at current engines, (2) Energy 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.

  11. Aircraft Energy Efficiency (ACEE) status report

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

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

  12. Effects of boundary layer refraction and fuselage scattering on fuselage surface noise from advanced turboprop propellers

    NASA Technical Reports Server (NTRS)

    Mcaninch, G. L.; Rawls, J. W., Jr.

    1984-01-01

    An acoustic disturbance's propagation through a boundary layer is discussed with a view to the analysis of the acoustic field generated by a propfan rotor incident to the fuselage of an aircraft. Applying the parallel flow assumption, the resulting partial differential equations are reduced to an ordinary acoustic pressure differential equation by means of the Fourier transform. The methods used for the solution of this equation include those of Frobenius and of analytic continuation; both yield exact solutions in series form. Two models of the aircraft fuselage-boundary layer system are considered, in the first of which the fuselage is replaced by a flat plate and the acoustic field is assumed to be two-dimensional, while in the second the fuselage is a cylinder in a fully three-dimensional acoustic field. It is shown that the boundary layer correction improves theory-data comparisons over simple application of a pressure-doubling rule at the fuselage.

  13. The NASA Aircraft Energy Efficiency program

    NASA Technical Reports Server (NTRS)

    Klineberg, J. M.

    1979-01-01

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

  14. Advanced turboprop wing installation effects measured by unsteady blade pressure and noise

    NASA Technical Reports Server (NTRS)

    Heidelberg, Laurence J.; Woodward, Richard P.

    1987-01-01

    A single rotation model propeller (SR-7A) was tested at simulated takeoff/approach conditions (Mach 0.2), in the NASA Lewis 9- by 15-Ft Anechoic Wind Tunnel. Both unsteady blade surface pressures and noise measurements were made for a tractor configuration with propeller/straight wing and propeller alone configurations. The angle between the wing chord and propeller axis (droop angle) was varied along with the wing angle of attack to determine the effects on noise and unsteady loading. A method was developed that uses unsteady blade pressure measurements to provide a quantitative indication of propeller inflow conditions, at least for a uniform (across the propeller disk) inflow angle. The wing installation caused a nearly uniform upwash at the propeller inlet as evidenced by the domination of the pressure spectra by the first shaft order. This inflow angle increased at a rate of almost 150 percent of that of the wing angle-of-attack for a propeller-wing spacing of 0.54 wing chords at a constant droop angle. The flyover noise, as measured by the maximum blade passing frequency level, correlates closely with the propeller inflow angle (approx. 0.6 dB per degree of inflow angle) for all droop angles and wing angles of attack tested, including the propeller alone data. Large changes in the unsteady pressure responses on the suction surface of the blade were observed as the advance ratio was varied. The presence of a leading edge vortex may explain this behavior since changes in the location of this vortex would change with loading (advance ratio).

  15. Performance and Environmental Assessment of an Advanced Aircraft with Open Rotor Propulsion

    NASA Technical Reports Server (NTRS)

    Guynn, Mark D.; Berton, Jeffrey J.; Haller, William J.; Hendricks, Eric S.; Tong, Michael T.

    2012-01-01

    Application of high speed, advanced turboprops, or "propfans," to transonic transport aircraft received significant attention during the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Unfortunately, after fuel prices declined sharply there was no longer sufficient motivation to continue maturing this technology. Recent volatility in fuel prices and increasing concern for aviation s environmental impact, however, have renewed interest in unducted, open rotor propulsion. Because of the renewed interest in open rotor propulsion, the lack of publicly available up-to-date studies assessing its benefits, and NASA s focus on reducing fuel consumption, a preliminary aircraft system level study on open rotor propulsion was initiated to inform decisions concerning research in this area. New analysis processes were established to assess the characteristics of open rotor aircraft. These processes were then used to assess the performance, noise, and emissions characteristics of an advanced, single-aisle aircraft using open rotor propulsion. The results of this initial study indicate open rotor engines have the potential to provide significant reductions in fuel consumption and landing-takeoff cycle NOX emissions. Noise analysis of the study configuration indicates that an open rotor aircraft in the single-aisle class would be able to meet current noise regulations with margin.

  16. Investigation of fuselage acoustic treatment for a twin-engine turboprop aircraft in flight and laboratory tests

    NASA Technical Reports Server (NTRS)

    Mixson, J. S.; Oneal, R. L.; Grosveld, F. W.

    1984-01-01

    A flight and laboratory study of sidewall acoustic treatment for cabin noise control is described. In flight, cabin noise levels were measured at six locations with three treatment configurations. Noise levels from narrow-band analysis are reduced to one-third octave format and used to calculate insertion loss, IL, defined as the reduction of interior noise associated with the addition of a treatment. Laboratory tests used a specially constructed structural panel modeled after the propeller plane section of the aircraft sidewall, and acoustic treatments representing those used in flight. Lab measured transmission loss and absorption values were combined using classical acoustic procedures to obtain a prediction of IL. Comparison with IL values measured in flight for the boundary layer component of the noise indicated general agreement.

  17. Cost/benefit analysis of advanced materials technology candidates for the 1980's, part 2

    NASA Technical Reports Server (NTRS)

    Dennis, R. E.; Maertins, H. F.

    1980-01-01

    Cost/benefit analyses to evaluate advanced material technologies projects considered for general aviation and turboprop commuter aircraft through estimated life-cycle costs, direct operating costs, and development costs are discussed. Specifically addressed is the selection of technologies to be evaluated; development of property goals; assessment of candidate technologies on typical engines and aircraft; sensitivity analysis of the changes in property goals on performance and economics, cost, and risk analysis for each technology; and ranking of each technology by relative value. The cost/benefit analysis was applied to a domestic, nonrevenue producing, business-type jet aircraft configured with two TFE731-3 turbofan engines, and to a domestic, nonrevenue producing, business type turboprop aircraft configured with two TPE331-10 turboprop engines. In addition, a cost/benefit analysis was applied to a commercial turboprop aircraft configured with a growth version of the TPE331-10.

  18. Advanced turboprop installation aerodynamics

    NASA Technical Reports Server (NTRS)

    Smith, R. C.

    1981-01-01

    The expected aerodynamic effects of a propfan installed on a thick supercritical wing are summarized qualitatively. Nacelle/wing and jet interactions, slipstream incremental velocity, nonuniform inflow, and swirl loss recovery are discussed.

  19. Initial Assessment of Open Rotor Propulsion Applied to an Advanced Single-Aisle Aircraft

    NASA Technical Reports Server (NTRS)

    Guynn, Mark D.; Berton, Jeffrey J.; Hendricks, Eric S.; Tong, Michael T.; Haller, William J.; Thurman, Douglas R.

    2011-01-01

    Application of high speed, advanced turboprops, or propfans, to subsonic transport aircraft received significant attention and research in the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Recent volatility in fuel prices and concern for aviation s environmental impact have renewed interest in unducted, open rotor propulsion, and revived research by NASA and a number of engine manufacturers. Unfortunately, in the two decades that have passed since open rotor concepts were thoroughly investigated, NASA has lost experience and expertise in this technology area. This paper describes initial efforts to re-establish NASA s capability to assess aircraft designs with open rotor propulsion. Specifically, methodologies for aircraft-level sizing, performance analysis, and system-level noise analysis are described. Propulsion modeling techniques have been described in a previous paper. Initial results from application of these methods to an advanced single-aisle aircraft using open rotor engines based on historical blade designs are presented. These results indicate open rotor engines have the potential to provide large reductions in fuel consumption and emissions. Initial noise analysis indicates that current noise regulations can be met with old blade designs and modern, noiseoptimized blade designs are expected to result in even lower noise levels. Although an initial capability has been established and initial results obtained, additional development work is necessary to make NASA s open rotor system analysis capability on par with existing turbofan analysis capabilities.

  20. Advanced Aircraft Structures program: an overview

    NASA Astrophysics Data System (ADS)

    Becker, Juergen; Schroeder, H. W.; Dittrich, Kay W.; Bauer, E. J.; Zippold, H.

    1999-07-01

    Requirements of future military aircraft structures are constantly increasing with advancing technological progress. While performance is still the main focus, costs have become a major issue in military aircraft procurement.In order to efficiently support its technological base oriented on the future demands of the market Daimler Chrysler Aerospace/Military Aircraft Division has inaugurated the Advanced Aircraft Structures Program, a collaborative research effort together with the German Aerospace Center and Daimler Chrysler Research and Technology, the corporate research division of Daimler Benz. The two key technologies to be pursued within the framework of this program are cost- effective composite structures and smart materials. This paper will give an overview of the Advanced Aircraft Structures Program with particular emphasis on smart structures technology as applied to active vibration damping, vibration isolation of equipment and composite health monitoring.

  1. Propulsion opportunities for future commuter aircraft

    NASA Technical Reports Server (NTRS)

    Strack, W. C.

    1982-01-01

    Circa 1990 propulsion improvement concepts are discussed for 1000 to 5000 SHP conventional turboprop powerplants including engines, gearboxes, and propellers. Cycle selection, power plant configurations and advanced technology elements are defined and evaluated using average stage length DOC for commuter aircraft as the primary merit criterion.

  2. Assessment Of Semi-Empirical Dynamic Stall Models For Turboprop Stall Calculations

    NASA Technical Reports Server (NTRS)

    Kaza, K. R. V.; Reddy, T. S. R.

    1989-01-01

    Report presents comparison of stall-flutter responses obtained from three semiempirical dynamic stall models. Part of effort to develop models for stall-flutter analysis of highly loaded propellers (advanced turboprops). Available models of dynamic stall applied to simple structural models to study extent of validity and select appropriate model for application to advanced turboprops. Conclusion during study is operating environment of advanced turboprop favors conditions of light stall, in which loads induced by vortexes not severe.

  3. Maneuvering technology for advanced fighter aircraft

    NASA Technical Reports Server (NTRS)

    Alexander, Michael G.; Harris, Scott H.; Byers, Richard H.

    1992-01-01

    The need for increased maneuverability has its genesis from the first aerial combat engagement when two adversaries entangled themselves in a deadly aerial dance trying to gain the advantage over the other. It has only been in the past two decades that technologies have been investigated to increase aircraft control at maneuver attitudes that are typically dominated by highly separated flows. These separated flow regions are aggravated by advanced fighter aircraft shapes required to defeat an electronic enemy. This paper discusses passive and active devices that can be used to enhance the maneuverability of advanced fighter aircraft through vortex flow control, boundary layer control, and innovative flow manipulation.

  4. Outlook for advanced concepts in transport aircraft

    NASA Technical Reports Server (NTRS)

    Conner, D. W.

    1980-01-01

    Air transportation demand trends, air transportation system goals, and air transportation system trends well into the 21st century were examined in detail. The outlook is for continued growth in both air passenger travel and air freight movements. The present system, with some improvements, is expected to continue to the turn of the century and to utilize technologically upgraded, derivative versions of today's aircraft, plus possibly some new aircraft for supersonic long haul, short haul, and high density commuter service. Severe constraints of the system, expected by early in the 21st century, should lead to innovations at the airport, away from the airport, and in the air. The innovations are illustrated by descriptions of three candidate systems involving advanced aircraft concepts. Advanced technologies and vehicles expected to impact the airport are illustrated by descriptions of laminar flow control aircraft, very large air freighters and cryogenically fueled transports.

  5. Advanced secondary power system for transport aircraft

    NASA Technical Reports Server (NTRS)

    Hoffman, A. C.; Hansen, I. G.; Beach, R. F.; Plencner, R. M.; Dengler, R. P.; Jefferies, K. S.; Frye, R. J.

    1985-01-01

    A concept for an advanced aircraft power system was identified that uses 20-kHz, 440-V, sin-wave power distribution. This system was integrated with an electrically powered flight control system and with other aircraft systems requiring secondary power. The resulting all-electric secondary power configuration reduced the empty weight of a modern 200-passenger, twin-engine transport by 10 percent and the mission fuel by 9 percent.

  6. Study of turboprop systems reliability and maintenance costs

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The overall reliability and maintenance costs (R&MC's) of past and current turboprop systems were examined. Maintenance cost drivers were found to be scheduled overhaul (40%), lack of modularity particularly in the propeller and reduction gearbox, and lack of inherent durability (reliability) of some parts. Comparisons were made between the 501-D13/54H60 turboprop system and the widely used JT8D turbofan. It was found that the total maintenance cost per flight hour of the turboprop was 75% higher than that of the JT8D turbofan. Part of this difference was due to propeller and gearbox costs being higher than those of the fan and reverser, but most of the difference was in the engine core where the older technology turboprop core maintenance costs were nearly 70 percent higher than for the turbofan. The estimated maintenance cost of both the advanced turboprop and advanced turbofan were less than the JT8D. The conclusion was that an advanced turboprop and an advanced turbofan, using similar cores, will have very competitive maintenance costs per flight hour.

  7. The NASA Aircraft Energy Efficiency Program

    NASA Technical Reports Server (NTRS)

    Klineberg, J. M.

    1978-01-01

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

  8. Studies of advanced transport aircraft

    NASA Technical Reports Server (NTRS)

    Nagel, A. L.

    1978-01-01

    Concepts for possible future airplanes are studied that include all-wing distributed-load airplanes, multi-body airplanes, a long-range laminar flow control airplane, a nuclear powered airplane designed for towing conventionally powered airplanes during long range cruise, and an aerial transportation system comprised of continuously flying liner airplanes operated in conjunction with short range feeder airplanes. Results indicate that each of these concepts has the potential for important performance and economic advantages, provided certain suggested research tasks are successfully accomplished. Indicated research areas include all-wing airplane aerodynamics, aerial rendezvous, nuclear aircraft engines, air-cushion landing systems, and laminar flow control, as well as the basic research discipline areas of aerodynamics, structures, propulsion, avionics, and computer applications.

  9. Studies of advanced transport aircraft

    NASA Technical Reports Server (NTRS)

    Nagel, A. L.

    1978-01-01

    Several concepts for possible future airplanes, including all-wing distributed-load airplanes, multibody airplanes, a long-range laminar flow control airplane, a nuclear-powered airplane designed for towing conventionally powered airplanes during long-range cruise, and an aerial transportation system comprised of continuously flying liner airplanes operated in conjunction with short-range feeder airplanes are described. Performance and economic advantages of each concept are indicated. Further research is recommended in the following areas: all-wing airplane aerodynamics, aerial rendezvous, nuclear aircraft engines, air-cushion landing systems, and laminar flow control, as well as the basic research discipline areas of aerodynamics, structures, propulsion, avionics, and computer applications.

  10. Pollution reduction technology program for turboprop engines

    NASA Technical Reports Server (NTRS)

    Tomlinson, J. G.

    1977-01-01

    The reduction of CO, HC, and smoke emissions while maintaining acceptable NO(x) emissions without affecting fuel consumption, durability, maintainability, and safety was accomplished. Component combustor concept screening directed toward the demonstration of advanced combustor technology required to meet the EPA exhaust emissions standards for class P2 turboprop engines was covered. The combustion system for the Allison 501-D22A engine was used, and three combustor design concepts - reverse flow, prechamber, and staged fuel were evaluated.

  11. 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.

  12. 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

  13. Annoyance caused by aircraft en route noise

    NASA Technical Reports Server (NTRS)

    Mccurdy, David A.

    1992-01-01

    A laboratory experiment was conducted to quantify the annoyance response of people on the ground to enroute noise generated by aircraft at cruise conditions. The en route noises were ground level recordings of eight advanced turboprop aircraft flyovers and six conventional turbofan flyovers. The eight advanced turboprop enroute noises represented the NASA Propfan Test Assessment aircraft operating at different combinations of altitude, aircraft Mach number, and propeller tip speed. The conventional turbofan en route noises represented six different commercial airliners. The overall durations of the en route noises varied from approximately 40 to 160 sec. In the experiment, 32 subjects judged the annoyance of the en route noises as well as recordings of the takeoff and landing noises of each of 5 conventional turboprop and 5 conventional turbofan aircraft. Each of the noises was presented at three sound pressure levels to the subjects in an anechoic listening room. Analysis of the judgments found small differences in annoyance between three combinations of aircraft type and operation. Current tone and corrections did not significantly improve en route annoyance prediction. The optimum duration-correction magnitude for en route noise was approximately 1 dB per doubling of effective duration.

  14. Advanced control technology and its potential for future transport aircraft

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The topics covered include fly by wire, digital control, control configured vehicles, applications to advanced flight vehicles, advanced propulsion control systems, and active control technology for transport aircraft.

  15. Advanced instrumentation for aircraft icing research

    NASA Technical Reports Server (NTRS)

    Bachalo, W.; Smith, J.; Rudoff, R.

    1990-01-01

    A compact and rugged probe based on the phase Doppler method was evaluated as a means for characterizing icing clouds using airborne platforms and for advancing aircraft icing research in large scale wind tunnels. The Phase Doppler Particle Analyzer (PDPA) upon which the new probe was based is now widely recognized as an accurate method for the complete characterization of sprays. The prototype fiber optic-based probe was evaluated in simulated aircraft icing clouds and found to have the qualities essential to providing information that will advance aircraft icing research. Measurement comparisons of the size and velocity distributions made with the standard PDPA and the fiber optic probe were in excellent agreement as were the measurements of number density and liquid water content. Preliminary testing in the NASA Lewis Icing Research Tunnel (IRT) produced reasonable results but revealed some problems with vibration and signal quality at high speeds. The cause of these problems were identified and design changes were proposed to eliminate the shortcomings of the probe.

  16. 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.

  17. Results of the pollution reduction technology program for turboprop engines

    NASA Technical Reports Server (NTRS)

    Mularz, E. J.

    1976-01-01

    A program was performed to evolve and demonstrate advanced combustor technology aimed at achieving the 1979 EPA standards for turboprop engines (Class P2). The engine selected for this program was the 501-D22A turboprop. Three combustor concepts were designed and tested in a combustor rig at the exact combustor operating conditions of the 50-D22A engine over the EPA landing-takeoff cycle. Each combustor concept exhibited pollutant emissions well below the EPA standards, achieving substantial reductions in unburned hydrocarbons, carbon monoxide, and smoke emissions compared with emissions from the production combustor of this engine. Oxides of nitrogen emissions remained well below the EPA standards, also.

  18. Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 5: Unsteady counterrotation ducted propfan analysis

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Delaney, Robert A.

    1993-01-01

    The primary objective of this study was the development of a time-marching three-dimensional Euler/Navier-Stokes aerodynamic analysis to predict steady and unsteady compressible transonic flows about ducted and unducted propfan propulsion systems employing multiple blade rows. The computer codes resulting from this study are referred to as ADPAC-AOAR\\CR (Advanced Ducted Propfan Analysis Codes-Angle of Attack Coupled Row). This document is the final report describing the theoretical basis and analytical results from the ADPAC-AOACR codes developed under task 5 of NASA Contract NAS3-25270, Unsteady Counterrotating Ducted Propfan Analysis. The ADPAC-AOACR Program is based on a flexible multiple blocked grid discretization scheme permitting coupled 2-D/3-D mesh block solutions with application to a wide variety of geometries. For convenience, several standard mesh block structures are described for turbomachinery applications. Aerodynamic calculations are based on a four-stage Runge-Kutta time-marching finite volume solution technique with added numerical dissipation. Steady flow predictions are accelerated by a multigrid procedure. Numerical calculations are compared with experimental data for several test cases to demonstrate the utility of this approach for predicting the aerodynamics of modern turbomachinery configurations employing multiple blade rows.

  19. Design and analysis of a fuel-efficient single-engine, turboprop-powered, business airplane

    NASA Technical Reports Server (NTRS)

    Martin, G. L.; Everest, D. E., Jr.; Lovell, W. A.; Price, J. E.; Walkley, K. B.; Washburn, G. F.

    1981-01-01

    The speed, range, payload, and fuel efficiency of a general aviation airplane powered by one turboprop engine was determined and compared to a twin engine turboprop aircraft. An airplane configuration was developed which can carry six people for a noreserve range of 2,408 km at a cruise speed above 154 m/s, and a cruise altitude of about 9,144 m. The cruise speed is comparable to that of the fastest of the current twin turboprop powered airplanes. It is found that the airplane has a cruise specific range greater than all twin turboprop engine airplanes flying in its speed range and most twin piston engine airplanes flying at considerably slower cruise airspeeds.

  20. Impact of Advanced Propeller Technology on Aircraft/Mission Characteristics of Several General Aviation Aircraft

    NASA Technical Reports Server (NTRS)

    Keiter, I. D.

    1982-01-01

    Studies of several General Aviation aircraft indicated that the application of advanced technologies to General Aviation propellers can reduce fuel consumption in future aircraft by a significant amount. Propeller blade weight reductions achieved through the use of composites, propeller efficiency and noise improvements achieved through the use of advanced concepts and improved propeller analytical design methods result in aircraft with lower operating cost, acquisition cost and gross weight.

  1. Advanced aircraft ignition CRADA final report

    SciTech Connect

    Early, J.W.

    1997-03-01

    Conventional commercial and military turbo-jet aircraft engines use capacitive discharge ignition systems to initiate fuel combustion. The fuel-rich conditions required to ensure engine re-ignition during flight yield less than optimal engine performance, which in turn reduces fuel economy and generates considerable pollution in the exhaust. Los Alamos investigated two approaches to advanced ignition: laser based and microwave based. The laser based approach is fuel ignition via laser-spark breakdown and via photo-dissociation of fuel hydrocarbons and oxygen. The microwave approach involves modeling, and if necessary redesigning, a combustor shape to form a low-Q microwave cavity, which will ensure microwave breakdown of the air/fuel mixture just ahead of the nozzle with or without a catalyst coating. This approach will also conduct radio-frequency (RF) heating of ceramic elements that have large loss tangents. Replacing conventional systems with either of these two new systems should yield combustion in leaner jet fuel/air mixtures. As a result, the aircraft would operate with (1) considerable less exhaust pollution, (2) lower engine maintenance, and (3) significantly higher fuel economy.

  2. Sikorsky Aircraft Advanced Rotorcraft Transmission (ART) program

    NASA Technical Reports Server (NTRS)

    Kish, Jules G.

    1993-01-01

    The objectives of the Advanced Rotorcraft Transmission program were to achieve a 25 percent weight reduction, a 10 dB noise reduction, and a 5,000 hour mean time between removals (MTBR). A three engine Army Cargo Aircraft (ACA) of 85,000 pounds gross weight was used as the baseline. Preliminary designs were conducted of split path and split torque transmissions to evaluate weight, reliability, and noise. A split path gearbox was determined to be 23 percent lighter, greater than 10 dB quieter, and almost four times more reliable than the baseline two stage planetary design. Detail design studies were conducted of the chosen split path configuration, and drawings were produced of a 1/2 size gearbox consisting of a single engine path of the split path section. Fabrication and testing was then conducted on the 1/2 size gearbox. The 1/2 size gearbox testing proved that the concept of the split path gearbox with high reduction ratio double helical output gear was sound. The improvements were attributed to extensive use of composites, spring clutches, advanced high hot hardness gear steels, the split path configuration itself, high reduction ratio, double helical gearing on the output stage, elastomeric load sharing devices, and elimination of accessory drives.

  3. Sikorsky Aircraft Advanced Rotorcraft Transmission (ART) program

    NASA Astrophysics Data System (ADS)

    Kish, Jules G.

    1993-03-01

    The objectives of the Advanced Rotorcraft Transmission program were to achieve a 25 percent weight reduction, a 10 dB noise reduction, and a 5,000 hour mean time between removals (MTBR). A three engine Army Cargo Aircraft (ACA) of 85,000 pounds gross weight was used as the baseline. Preliminary designs were conducted of split path and split torque transmissions to evaluate weight, reliability, and noise. A split path gearbox was determined to be 23 percent lighter, greater than 10 dB quieter, and almost four times more reliable than the baseline two stage planetary design. Detail design studies were conducted of the chosen split path configuration, and drawings were produced of a 1/2 size gearbox consisting of a single engine path of the split path section. Fabrication and testing was then conducted on the 1/2 size gearbox. The 1/2 size gearbox testing proved that the concept of the split path gearbox with high reduction ratio double helical output gear was sound. The improvements were attributed to extensive use of composites, spring clutches, advanced high hot hardness gear steels, the split path configuration itself, high reduction ratio, double helical gearing on the output stage, elastomeric load sharing devices, and elimination of accessory drives.

  4. Systems study of transport aircraft incorporating advanced aluminum alloys

    NASA Technical Reports Server (NTRS)

    Sakata, I. F.

    1982-01-01

    A study was performed to quantify the potential benefits of utilizing advanced aluminum alloys in commercial transport aircraft and to define the effort necessary to develop fully the alloys to a viable commercial production capability. The comprehensive investigation (1) established realistic advanced aluminum alloy property goals to maximize aircraft systems effectiveness (2) identified performance and economic benefits of incorporating the advanced alloy in future advanced technology commercial aircraft designs (3) provided a recommended plan for development and integration of the alloys into commercial aircraft production (4) provided an indication of the timing and investigation required by the metal producing industry to support the projected market and (5) evaluate application of advanced aluminum alloys to other aerospace and transit systems as a secondary objective. The results of the investigation provided a roadmap and identified key issues requiring attention in an advanced aluminum alloy and applications technology development program.

  5. Human factors of advanced technology (glass cockpit) transport aircraft

    NASA Technical Reports Server (NTRS)

    Wiener, Earl L.

    1989-01-01

    A three-year study of airline crews at two U.S. airlines who were flying an advanced technology aircraft, the Boeing 757 is discussed. The opinions and experiences of these pilots as they view the advanced, automated features of this aircraft, and contrast them with previous models they have flown are discussed. Training for advanced automation; (2) cockpit errors and error reduction; (3) management of cockpit workload; and (4) general attitudes toward cockpit automation are emphasized. The limitations of the air traffic control (ATC) system on the ability to utilize the advanced features of the new aircraft are discussed. In general the pilots are enthusiastic about flying an advanced technology aircraft, but they express mixed feelings about the impact of automation on workload, crew errors, and ability to manage the flight.

  6. Advanced organic composite materials for aircraft structures: Future program

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Revolutionary advances in structural materials have been responsible for revolutionary changes in all fields of engineering. These advances have had and are still having a significant impact on aircraft design and performance. Composites are engineered materials. Their properties are tailored through the use of a mix or blend of different constituents to maximize selected properties of strength and/or stiffness at reduced weights. More than 20 years have passed since the potentials of filamentary composite materials were identified. During the 1970s much lower cost carbon filaments became a reality and gradually designers turned from boron to carbon composites. Despite progress in this field, filamentary composites still have significant unfulfilled potential for increasing aircraft productivity; the rendering of advanced organic composite materials into production aircraft structures was disappointingly slow. Why this is and research and technology development actions that will assist in accelerating the application of advanced organic composites to production aircraft is discussed.

  7. Advanced Air Data Systems for Commercial Aircraft

    NASA Technical Reports Server (NTRS)

    2006-01-01

    It is possible to get a crude estimate of wind speed and direction while driving a car at night in the rain, with the motion of the raindrop reflections in the headlights providing clues about the wind. The clues are difficult to interpret, though, because of the relative motions of ground, car, air, and raindrops. More subtle interpretation is possible if the rain is replaced by fog, because the tiny droplets would follow the swirling currents of air around an illuminated object, like, for example, a walking pedestrian. Microscopic particles in the air (aerosols) are better for helping make assessments of the wind, and reflective air molecules are best of all, providing the most refined measurements. It takes a bright light to penetrate fog, so it is easy to understand how other factors, like replacing the headlights with the intensity of a searchlight, can be advantageous. This is the basic principle behind a lidar system. While a radar system transmits a pulse of radiofrequency energy and interprets the received reflections, a lidar system works in a similar fashion, substituting a near-optical laser pulse. The technique allows the measurement of relative positions and velocities between the transmitter and the air, which allows measurements of relative wind and of air temperature (because temperature is associated with high-frequency random motions on a molecular level). NASA, as well as the National Oceanic and Atmospheric Administration (NOAA), have interests in this advanced lidar technology, as much of their explorative research requires the ability to measure winds and turbulent regions within the atmosphere. Lidar also shows promise for providing warning of turbulent regions within the National Airspace System to allow commercial aircraft to avoid encounters with turbulence and thereby increase the safety of the traveling public. Both agencies currently employ lidar and optical sensing for a variety of weather-related research projects, such as analyzing

  8. The X-31 aircraft: Advances in aircraft agility and performance

    NASA Astrophysics Data System (ADS)

    Alcorn, C. W.; Croom, M. A.; Francis, M. S.; Ross, H.

    1996-08-01

    The X-31 enhanced fighter maneuverability (EFM) demonstrator has pioneered agile flight in the post-stall flight regime and explored integrated multi-axis thrust vectoring across a broad flight envelope. Its maneuvering achievements include sustained flight up to 70 degrees angle of attack, velocity vector rolls in deep post-stall conditions, and post-stall turns from high entry to exit speeds with ultra low turning/transitional conditions. The concept of post-stall maneuverability was extensively studied in simulations preceding initiation of the X-31 program. These simulations provided a baseline for tactical utility demonstrations and vehicle design requirements. Post-stall maneuverability was not achieved without encountering and mitigating the effects of highly unsteady, asymmetric, vortex-dominated flow-fields associated with post-stall flight. Anomalies in vehicle response to control inputs were observed at high angles of attack, as were differences between simulator and actual flight parameters due to a misrepresentation of the effects of these complex flowfields. Some preliminary force and moment data for the X-31 configuration during dynamic maneuvers are provided to highlight the complex nature of the flowfield. The X-31 aircraft's enabling capabilities, including multi-axis thrust vectoring and integrated flight/propulsion control also provided performance enhancements across the entire flight envelope. In what were known as ‘quasi-tailless’ experiments, conventional aerodynamic control surfaces were used to reduce or eliminate the stabilizing influence of the vertical stabilizer, while the vehicle's multi-axis thrust vectoring capability was used for restabilization. Properly exploited, these technologies can lead to the reduction or elimination of traditional aerodynamic control surfaces, which provides profound improvements in vehicle range, weight, payload, and low observability. This review focuses on some of the principal aerodynamic issues

  9. Technology for aircraft energy efficiency

    NASA Technical Reports Server (NTRS)

    Klineberg, J. M.

    1977-01-01

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

  10. Mission Analysis and Aircraft Sizing of a Hybrid-Electric Regional Aircraft

    NASA Technical Reports Server (NTRS)

    Antcliff, Kevin R.; Guynn, Mark D.; Marien, Ty V.; Wells, Douglas P.; Schneider, Steven J.; Tong, Michael T.

    2016-01-01

    The purpose of this study was to explore advanced airframe and propulsion technologies for a small regional transport aircraft concept (approximately 50 passengers), with the goal of creating a conceptual design that delivers significant cost and performance advantages over current aircraft in that class. In turn, this could encourage airlines to open up new markets, reestablish service at smaller airports, and increase mobility and connectivity for all passengers. To meet these study goals, hybrid-electric propulsion was analyzed as the primary enabling technology. The advanced regional aircraft is analyzed with four levels of electrification, 0 percent electric with 100 percent conventional, 25 percent electric with 75 percent conventional, 50 percent electric with 50 percent conventional, and 75 percent electric with 25 percent conventional for comparison purposes. Engine models were developed to represent projected future turboprop engine performance with advanced technology and estimates of the engine weights and flowpath dimensions were developed. A low-order multi-disciplinary optimization (MDO) environment was created that could capture the unique features of parallel hybrid-electric aircraft. It is determined that at the size and range of the advanced turboprop: The battery specific energy must be 750 watt-hours per kilogram or greater for the total energy to be less than for a conventional aircraft. A hybrid vehicle would likely not be economically feasible with a battery specific energy of 500 or 750 watt-hours per kilogram based on the higher gross weight, operating empty weight, and energy costs compared to a conventional turboprop. The battery specific energy would need to reach 1000 watt-hours per kilogram by 2030 to make the electrification of its propulsion an economically feasible option. A shorter range and/or an altered propulsion-airframe integration could provide more favorable results.

  11. Applications of advanced electric/electronic technology to conventional aircraft

    NASA Technical Reports Server (NTRS)

    Heimbold, R. L.

    1980-01-01

    The desirability of seven advanced technologies as applied to three commercial aircraft of 1985 to 1995 was investigated. Digital fly by wire, multiplexing, ring laser gyro, integrated avionics, all electric airplane, electric load management, and fiber optics were considered for 500 passenger, 50 passenger, and 30 passenger aircraft. The major figure of merit used was Net Value of Technology based on procurement and operating cost over the life of the aircraft. An existing computer program, ASSET, was used to resize the aircraft and evalute fuel usage and maintenance costs for each candidate configuration. Conclusions were that, for the 500 passenger aircraft, all candidates had a worthwhile payoff with the all electric airplane having a large payoff.

  12. Aerodynamic design and performance testing of an advanced 30 deg swept, eight bladed propeller at Mach numbers from 0.2 to 0.85

    NASA Technical Reports Server (NTRS)

    Black, D. M.; Menthe, R. W.; Wainauski, H. S.

    1978-01-01

    The increased emphasis on fuel conservation in the world has stimulated a series of studies of both conventional and unconventional propulsion systems for commercial aircraft. Preliminary results from these studies indicate that a fuel saving of from 15 to 28 percent may be realized by the use of an advanced high speed turboprop. The turboprop must be capable of high efficiency at Mach 0.8 above 10.68 km (35,000 ft) altitude if it is to compete with turbofan powered commercial aircraft. An advanced turboprop concept was wind tunnel tested. The model included such concepts as an aerodynamically integrated propeller/nacelle, blade sweep and power (disk) loadings approximately three times higher than conventional propeller designs. The aerodynamic design for the model is discussed. Test results are presented which indicate propeller net efficiencies near 80 percent were obtained at high disk loadings at Mach 0.8.

  13. Advanced methods of structural and trajectory analysis for transport aircraft

    NASA Technical Reports Server (NTRS)

    Ardema, Mark D.

    1995-01-01

    This report summarizes the efforts in two areas: (1) development of advanced methods of structural weight estimation, and (2) development of advanced methods of trajectory optimization. The majority of the effort was spent in the structural weight area. A draft of 'Analytical Fuselage and Wing Weight Estimation of Transport Aircraft', resulting from this research, is included as an appendix.

  14. Energy and Economic Trade Offs for Advanced Technology Subsonic Aircraft

    NASA Technical Reports Server (NTRS)

    Maddalon, D. V.; Wagner, R. D.

    1976-01-01

    Changes in future aircraft technology which conserve energy are studied, along with the effect of these changes on economic performance. Among the new technologies considered are laminar-flow control, composite materials with and without laminar-flow control, and advanced airfoils. Aircraft design features studied include high-aspect-ratio wings, thickness ratio, and range. Engine technology is held constant at the JT9D level. It is concluded that wing aspect ratios of future aircraft are likely to significantly increase as a result of new technology and the push of higher fuel prices. Composite materials may raise aspect radio to about 11 to 12 and practical laminar flow-control systems may further increase aspect ratio to 14 or more. Advanced technology provides significant reductions in aircraft take-off gross weight, energy consumption, and direct operating cost.

  15. Pollution Reduction Technology Program, Turboprop Engines, Phase 1

    NASA Technical Reports Server (NTRS)

    Anderson, R. D.; Herman, A. S.; Tomlinson, J. G.; Vaught, J. M.; Verdouw, A. J.

    1976-01-01

    Exhaust pollutant emissions were measured from a 501-D22A turboprop engine combustor and three low emission combustor types -- reverse flow, prechamber, and staged fuel, operating over a fuel-air ratio range of .0096 to .020. The EPAP LTO cycle data were obtained for a total of nineteen configurations. Hydrocarbon emissions were reduced from 15.0 to .3 lb/1000 Hp-Hr/cycle, CO from 31.5 to 4.6 lb/1000 Hp-Hr/cycle with an increase in NOx of 17 percent, which is still 25% below the program goal. The smoke number was reduced from 59 to 17. Emissions given here are for the reverse flow Mod. IV combustor which is the best candidate for further development into eventual use with the 501-D22A turboprop engine. Even lower emissions were obtained with the advanced technology combustors.

  16. Preliminary design studies of an advanced general aviation aircraft

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Preliminary design studies are presented for an advanced general aviation aircraft. Advanced guidance and display concepts, laminar flow, smart structures, fuselage and wing structural design and manufacturing, and preliminary configuration design are discussed. This project was conducted as a graduate level design class under the auspices of the KU/NASA/USRA Advanced Design Program in Aeronautics. The results obtained during the fall semester of 1990 (Phase 1) and the spring semester of 1991 (Phase 2) are presented.

  17. Advanced textile applications for primary aircraft structures

    NASA Technical Reports Server (NTRS)

    Jackson, Anthony C.; Barrie, Ronald E.; Shah, Bharat M.; Shukla, Jay G.

    1992-01-01

    Advanced composite primary structural concepts were evaluated for low cost, damage tolerant structures. Development of advanced textile preforms for fuselage structural applications with resin transfer molding and powder epoxy materials are now under development.

  18. Advanced textile applications for primary aircraft structures

    NASA Technical Reports Server (NTRS)

    Jackson, Anthony C.; Barrie, Ronald E.; Shah, Bharat M.; Shukla, Jay G.

    1992-01-01

    Advanced composite primary structural concepts have been evaluated for low cost, damage tolerant structures. Development of advanced textile preforms for fuselage structural applications with resin transfer molding and powder epoxy material is now under development.

  19. Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 4: Advanced fan section aerodynamic analysis computer program user's manual

    NASA Technical Reports Server (NTRS)

    Crook, Andrew J.; Delaney, Robert A.

    1992-01-01

    The computer program user's manual for the ADPACAPES (Advanced Ducted Propfan Analysis Code-Average Passage Engine Simulation) program is included. The objective of the computer program is development of a three-dimensional Euler/Navier-Stokes flow analysis for fan section/engine geometries containing multiple blade rows and multiple spanwise flow splitters. An existing procedure developed by Dr. J. J. Adamczyk and associates at the NASA Lewis Research Center was modified to accept multiple spanwise splitter geometries and simulate engine core conditions. The numerical solution is based upon a finite volume technique with a four stage Runge-Kutta time marching procedure. Multiple blade row solutions are based upon the average-passage system of equations. The numerical solutions are performed on an H-type grid system, with meshes meeting the requirement of maintaining a common axisymmetric mesh for each blade row grid. The analysis was run on several geometry configurations ranging from one to five blade rows and from one to four radial flow splitters. The efficiency of the solution procedure was shown to be the same as the original analysis.

  20. Toward improved durability in advanced aircraft engine hot sections

    NASA Technical Reports Server (NTRS)

    Sokolowski, Daniel E. (Editor)

    1989-01-01

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

  1. Advances in Fatigue and Fracture Mechanics Analyses for Aircraft Structures

    NASA Technical Reports Server (NTRS)

    Newman, J. C., Jr.

    1999-01-01

    This paper reviews some of the advances that have been made in stress analyses of cracked aircraft components, in the understanding of the fatigue and fatigue-crack growth process, and in the prediction of residual strength of complex aircraft structures with widespread fatigue damage. Finite-element analyses of cracked structures are now used to determine accurate stress-intensity factors for cracks at structural details. Observations of small-crack behavior at open and rivet-loaded holes and the development of small-crack theory has lead to the prediction of stress-life behavior for components with stress concentrations under aircraft spectrum loading. Fatigue-crack growth under simulated aircraft spectra can now be predicted with the crack-closure concept. Residual strength of cracked panels with severe out-of-plane deformations (buckling) in the presence of stiffeners and multiple-site damage can be predicted with advanced elastic-plastic finite-element analyses and the critical crack-tip-opening angle (CTOA) fracture criterion. These advances are helping to assure continued safety of aircraft structures.

  2. Preliminary aerodynamic design considerations for advanced laminar flow aircraft configurations

    NASA Technical Reports Server (NTRS)

    Johnson, Joseph L., Jr.; Yip, Long P.; Jordan, Frank L., Jr.

    1986-01-01

    Modern composite manufacturing methods have provided the opportunity for smooth surfaces that can sustain large regions of natural laminar flow (NLF) boundary layer behavior and have stimulated interest in developing advanced NLF airfoils and improved aircraft designs. Some of the preliminary results obtained in exploratory research investigations on advanced aircraft configurations at the NASA Langley Research Center are discussed. Results of the initial studies have shown that the aerodynamic effects of configuration variables such as canard/wing arrangements, airfoils, and pusher-type and tractor-type propeller installations can be particularly significant at high angles of attack. Flow field interactions between aircraft components were shown to produce undesirable aerodynamic effects on a wing behind a heavily loaded canard, and the use of properly designed wing leading-edge modifications, such as a leading-edge droop, offset the undesirable aerodynamic effects by delaying wing stall and providing increased stall/spin resistance with minimum degradation of laminar flow behavior.

  3. Advanced short haul aircraft for high density markets

    NASA Technical Reports Server (NTRS)

    Galloway, T. L.

    1977-01-01

    The short haul (less than 500 miles) passenger enplanements represent about 50% of the total domestic enplanements. These can be distinguished by the annual passenger flow for a given city pair and classified into low, medium and high densiy markets. NASA studies have investigated various advanced short haul aircraft concepts that have potential application in these three market areas. Although advanced operational techniques impact all market densities, advanced vehicle design concepts such as RTOL, STOL and VTOL have the largest impact in the high density markets. This paper summarizes the results of NASA sponsored high density short haul air transportation systems studies and briefly reviews NASA sponsored advanced VTOL conceptual aircraft design studies. Trends in vehicle characteristics and operational requirements will be indicated in addition to economic suitability and impact on the community.

  4. High speed turboprop aeroacoustic study (counterrotation). Volume 1: Model development

    NASA Technical Reports Server (NTRS)

    Whitfield, C. E.; Mani, R.; Gliebe, P. R.

    1990-01-01

    The isolated counterrotating high speed turboprop noise prediction program was compared with model data taken in the GE Aircraft Engines Cell 41 anechoic facility, the Boeing Transonic Wind Tunnel, and in NASA-Lewis' 8x6 and 9x15 wind tunnels. The predictions show good agreement with measured data under both low and high speed simulated flight conditions. The installation effect model developed for single rotation, high speed turboprops was extended to include counterotation. The additional effect of mounting a pylon upstream of the forward rotor was included in the flow field modeling. A nontraditional mechanism concerning the acoustic radiation from a propeller at angle of attach was investigated. Predictions made using this approach show results that are in much closer agreement with measurement over a range of operating conditions than those obtained via traditional fluctuating force methods. The isolated rotors and installation effects models were combines into a single prediction program, results of which were compared with data taken during the flight test of the B727/UDF engine demonstrator aircraft. Satisfactory comparisons between prediction and measured data for the demonstrator airplane, together with the identification of a nontraditional radiation mechanism for propellers at angle of attack are achieved.

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

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  6. Terminal area considerations for an advanced CTOL transport aircraft

    NASA Technical Reports Server (NTRS)

    Sussman, M. B.

    1975-01-01

    Projected future conditions at large urban airports were used to identify design objectives for a long-haul, advanced transport airplane introduced for operation in the mid-1980s. Operating constraints associated with airport congestion and aircraft noise and emissions were of central interest. In addition, some of the interaction of these constraints with aircraft fuel usage were identified. The study allowed for advanced aircraft design features consistent with the future operating period. A baseline 200 passenger airplane design was modified to comply with design requirements imposed by terminal area constraints. Specific design changes included: (1) modification of engine arrangement; wing planform; (2) drag and spoiler surfaces; (3) secondary power systems; (4) brake and landing gear characteristics; and (5) the aircraft avionics. These changes, based on exploratory design estimates and allowing for technology advance, were judged to enable the airplane to: reduce wake turbulence; handle steeper descent paths with fewer limitation due to engine characteristics; reduce runway occupancy times; improve community noise contours; and reduce the total engine emittants deposited in the terminal area. The penalties to airplane performance and operating cost associated with improving the terminal area characteristics of the airplane were assessed. Finally, key research problems requiring solution in order to validate the assumed advanced airplane technology were identified.

  7. Study of advanced fuel system concepts for commercial aircraft

    NASA Technical Reports Server (NTRS)

    Coffinberry, G. A.

    1985-01-01

    An analytical study was performed in order to assess relative performance and economic factors involved with alternative advanced fuel systems for future commercial aircraft operating with broadened property fuels. The DC-10-30 wide-body tri-jet aircraft and the CF6-8OX engine were used as a baseline design for the study. Three advanced systems were considered and were specifically aimed at addressing freezing point, thermal stability and lubricity fuel properties. Actual DC-10-30 routes and flight profiles were simulated by computer modeling and resulted in prediction of aircraft and engine fuel system temperatures during a nominal flight and during statistical one-day-per-year cold and hot flights. Emergency conditions were also evaluated. Fuel consumption and weight and power extraction results were obtained. An economic analysis was performed for new aircraft and systems. Advanced system means for fuel tank heating included fuel recirculation loops using engine lube heat and generator heat. Environmental control system bleed air heat was used for tank heating in a water recirculation loop. The results showed that fundamentally all of the three advanced systems are feasible but vary in their degree of compatibility with broadened-property fuel.

  8. Advanced NDE techniques for quantitative characterization of aircraft

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S.; Winfree, William P.

    1990-01-01

    Recent advances in nondestructive evaluation (NDE) at NASA Langley Research Center and their applications that have resulted in quantitative assessment of material properties based on thermal and ultrasonic measurements are reviewed. Specific applications include ultrasonic determination of bolt tension, ultrasonic and thermal characterization of bonded layered structures, characterization of composite materials, and disbonds in aircraft skins.

  9. Design of the advanced regional aircraft, the DART-75

    NASA Technical Reports Server (NTRS)

    Elliott, Steve; Gislason, Jason; Huffstetler, Mark; Mann, Jon; Withers, Ashley; Zimmerman, Mark

    1992-01-01

    This design analysis is intended to show the capabilities of the DART-75, a 75 passenger medium-range regional transport. Included are the detailed descriptions of the structures, performance, stability and control, weight and balance, and engine design. The design should allow for the DART to become the premier regional aircraft of the future due to some advanced features like the canard, semi-composite construction, and advanced engines.

  10. Applications of advanced transport aircraft in developing countries

    NASA Technical Reports Server (NTRS)

    Gobetz, F. W.; Assarabowski, R. J.; Leshane, A. A.

    1978-01-01

    Four representative market scenarios were studied to evaluate the relative performance of air-and surface-based transportation systems in meeting the needs of two developing contries, Brazil and Indonesia, which were selected for detailed case studies. The market scenarios were: remote mining, low-density transport, tropical forestry, and large cargo aircraft serving processing centers in resource-rich, remote areas. The long-term potential of various aircraft types, together with fleet requirements and necessary technology advances, is determined for each application.

  11. Preliminary design studies of an advanced general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Barrett, Ron; Demoss, Shane; Dirkzwager, AB; Evans, Darryl; Gomer, Charles; Keiter, Jerry; Knipp, Darren; Seier, Glen; Smith, Steve; Wenninger, ED

    1991-01-01

    The preliminary design results are presented of the advanced aircraft design project. The goal was to take a revolutionary look into the design of a general aviation aircraft. Phase 1 of the project included the preliminary design of two configurations, a pusher, and a tractor. Phase 2 included the selection of only one configuration for further study. The pusher configuration was selected on the basis of performance characteristics, cabin noise, natural laminar flow, and system layouts. The design was then iterated to achieve higher levels of performance.

  12. Advances in Experiment Design for High Performance Aircraft

    NASA Technical Reports Server (NTRS)

    Morelli, Engene A.

    1998-01-01

    A general overview and summary of recent advances in experiment design for high performance aircraft is presented, along with results from flight tests. General theoretical background is included, with some discussion of various approaches to maneuver design. Flight test examples from the F-18 High Alpha Research Vehicle (HARV) are used to illustrate applications of the theory. Input forms are compared using Cramer-Rao bounds for the standard errors of estimated model parameters. Directions for future research in experiment design for high performance aircraft are identified.

  13. Lightweight, Efficient Power Converters for Advanced Turboelectric Aircraft Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Hennessy, Michael J.

    2014-01-01

    NASA is investigating advanced turboelectric aircraft propulsion systems that use superconducting motors to drive multiple distributed turbofans. Conventional electric motors are too large and heavy to be practical for this application; therefore, superconducting motors are required. In order to improve aircraft maneuverability, variable-speed power converters are required to throttle power to the turbofans. The low operating temperature and the need for lightweight components that place a minimum of additional heat load on the refrigeration system open the possibility of incorporating extremely efficient cryogenic power conversion technology. This Phase II project is developing critical components required to meet these goals.

  14. Advanced composite stabilizer for Boeing 737 aircraft

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Activities related to development of an advanced composites stabilizer for the Boeing 737 commercial transport are reported. Activities include discussion of criteria and objectives, design loads, the fatigue spectrum definition to be used for all spectrum fatigue testing, fatigue analysis, manufacturing producibility studies, the ancillary test program, quality assurance, and manufacturing development.

  15. Advanced composite elevator for Boeing 727 aircraft

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Detail design activities are reported for a program to develop an advanced composites elevator for the Boeing 727 commercial transport. Design activities include discussion and results of the ancillary test programs, sustaining efforts, weight status, manufacturing producibility studies, quality assurance development, and production status.

  16. Technology Advancements Enhance Aircraft Support of Experiment Campaigns

    NASA Technical Reports Server (NTRS)

    Vachon, Jacques J.

    2009-01-01

    For over 30 years, the NASA Airborne Science Program has provided airborne platforms for space bound instrument development, for calibrating new and existing satellite systems, and for making in situ and remote sensing measurements that can only be made from aircraft. New technologies have expanded the capabilities of aircraft that are operated for these missions. Over the last several years a new technology investment portfolio has yielded improvements that produce better measurements for the airborne science communities. These new technologies include unmanned vehicles, precision trajectory control and advanced telecommunications capabilities. We will discuss some of the benefits of these new technologies and systems which aim to provide users with more precision, lower operational costs, quicker access to data, and better management of multi aircraft and multi sensor campaigns.

  17. Advanced composite stabilizer for Boeing 737 aircraft

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Activities related to development of an advanced composites stabilizer for the Boeing 737 commercial transport are reported. Activities include discussion of the design and weight status, stiffness requirements, the finite element model, test programs, quality assurance, and manufacturing producibility studies. Design details of the graphite/epoxy components are virtually complete. Emphasis is placed on the metal and fiberglass trailing edge components. The bending and torsional stiffness properties are satisfactory for both stability/control and for flutter requirements. The finite element model input geometry is revised to reflect the latest changes to production drawings.

  18. Energy and economic trade offs for advanced technology subsonic aircraft

    NASA Technical Reports Server (NTRS)

    Maddalon, D. V.; Wagner, R. D.

    1976-01-01

    Changes in future aircraft technology which conserve energy are studied, along with the effect of these changes on economic performance. Among the new technologies considered are laminar-flow control, composite materials with and without laminar-flow control, and advanced airfoils. Aircraft design features studied include high-aspect-ratio wings, thickness ratio, and range. Engine technology is held constant at the JT9D level. It is concluded that wing aspect ratios of future aircraft are likely to significantly increase as a result of new technology and the push of higher fuel prices. Whereas current airplanes have been designed for AR = 7, supercritical technology and much higher fuel prices will drive aspect ratio to the AR = 9-10 range. Composite materials may raise aspect ratio to about 11-12 and practical laminar flow-control systems may further increase aspect ratio to 14 or more. Advanced technology provides significant reductions in aircraft take-off gross weight, energy consumption, and direct operating cost.

  19. 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.

  20. Overview of liquid lubricants for advanced aircraft

    NASA Technical Reports Server (NTRS)

    Loomis, W. R.

    1982-01-01

    An overall status report on liquid lubricants for use in high-performance turbojet engines is presented. Emphasis is placed on the oxidation and thermal stability requirements imposed upon the lubrication system. A brief history is iven of the development of turbine engine lubricants which led to synthetic oils with their inherent modification advantages. The status and state of development of some nine 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. Also, alternatives to high temperature fluid development are described. The importance of of continuing work on improving high temperature lubricant candidates and encouraging development of fluid base stocks is discussed.

  1. Advanced Multispectral Scanner (AMS) study. [aircraft remote sensing

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The status of aircraft multispectral scanner technology was accessed in order to develop preliminary design specifications for an advanced instrument to be used for remote sensing data collection by aircraft in the 1980 time frame. The system designed provides a no-moving parts multispectral scanning capability through the exploitation of linear array charge coupled device technology and advanced electronic signal processing techniques. Major advantages include: 10:1 V/H rate capability; 120 deg FOV at V/H = 0.25 rad/sec; 1 to 2 rad resolution; high sensitivity; large dynamic range capability; geometric fidelity; roll compensation; modularity; long life; and 24 channel data acquisition capability. The field flattening techniques of the optical design allow wide field view to be achieved at fast f/nos for both the long and short wavelength regions. The digital signal averaging technique permits maximization of signal to noise performance over the entire V/H rate range.

  2. Advances in experimental mechanics for advanced aircraft structures

    NASA Astrophysics Data System (ADS)

    O'Brien, Eddie W.

    1997-03-01

    The industrial requirement for higher efficiency, lean performance, airframe structures to form the basis of more cost effective Commercial Aircraft has encouraged developments in all aspects of aeronautical design and manufacture. Until recently the main emphasis has been in the area of computer and numerical analysis, however new developments in experimental mechanics are emerging as very powerful tools for use in the validation of numerical analyses and for primary stress analysis data. The developments described have been forced by economic drivers that address more efficient analysis techniques with respect to cost, specific weight and expended time for analysis.

  3. Potential for Landing Gear Noise Reduction on Advanced Aircraft Configurations

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Nickol, Craig L.; Burley, Casey L.; Guo, Yueping

    2016-01-01

    The potential of significantly reducing aircraft landing gear noise is explored for aircraft configurations with engines installed above the wings or the fuselage. An innovative concept is studied that does not alter the main gear assembly itself but does shorten the main strut and integrates the gear in pods whose interior surfaces are treated with acoustic liner. The concept is meant to achieve maximum noise reduction so that main landing gears can be eliminated as a major source of airframe noise. By applying this concept to an aircraft configuration with 2025 entry-into-service technology levels, it is shown that compared to noise levels of current technology, the main gear noise can be reduced by 10 EPNL dB, bringing the main gear noise close to a floor established by other components such as the nose gear. The assessment of the noise reduction potential accounts for design features for the advanced aircraft configuration and includes the effects of local flow velocity in and around the pods, gear noise reflection from the airframe, and reflection and attenuation from acoustic liner treatment on pod surfaces and doors. A technical roadmap for maturing this concept is discussed, and the possible drag increase at cruise due to the addition of the pods is identified as a challenge, which needs to be quantified and minimized possibly with the combination of detailed design and application of drag reduction technologies.

  4. Structural Configuration Systems Analysis for Advanced Aircraft Fuselage Concepts

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivek; Welstead, Jason R.; Quinlan, Jesse R.; Guynn, Mark D.

    2016-01-01

    Structural configuration analysis of an advanced aircraft fuselage concept is investigated. This concept is characterized by a double-bubble section fuselage with rear mounted engines. Based on lessons learned from structural systems analysis of unconventional aircraft, high-fidelity finite-element models (FEM) are developed for evaluating structural performance of three double-bubble section configurations. Structural sizing and stress analysis are applied for design improvement and weight reduction. Among the three double-bubble configurations, the double-D cross-section fuselage design was found to have a relatively lower structural weight. The structural FEM weights of these three double-bubble fuselage section concepts are also compared with several cylindrical fuselage models. Since these fuselage concepts are different in size, shape and material, the fuselage structural FEM weights are normalized by the corresponding passenger floor area for a relative comparison. This structural systems analysis indicates that an advanced composite double-D section fuselage may have a relative structural weight ratio advantage over a conventional aluminum fuselage. Ten commercial and conceptual aircraft fuselage structural weight estimates, which are empirically derived from the corresponding maximum takeoff gross weight, are also presented and compared with the FEM- based estimates for possible correlation. A conceptual full vehicle FEM model with a double-D fuselage is also developed for preliminary structural analysis and weight estimation.

  5. Status of Advanced Stitched Unitized Composite Aircraft Structures

    NASA Technical Reports Server (NTRS)

    Jegley, Dawn C.; Velicki, Alex

    2013-01-01

    NASA has created the Environmentally Responsible Aviation (ERA) Project to explore and document the feasibility, benefits and technical risk of advanced vehicle configurations and enabling technologies that will reduce the impact of aviation on the environment. A critical aspect of this pursuit is the development of a lighter, more robust airframe that will enable the introduction of unconventional aircraft configurations that have higher lift-to-drag ratios, reduced drag, and lower community noise levels. The primary structural concept being developed under the ERA project in the Airframe Technology element is the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) concept. This paper describes how researchers at NASA and The Boeing Company are working together to develop fundamental PRSEUS technologies that could someday be implemented on a transport size aircraft with high aspect ratio wings or unconventional shapes such as a hybrid wing body airplane design.

  6. Civil benefits of the JVX. [Joint Services Advanced Lift Aircraft

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1984-01-01

    The inherently high productivity, VTOL capability, and low noise and vibration features of a civil version of the Joint Services Advanced Vertical Lift Aircraft, or 'JVX', are recommended for commercial exploitation. This tilt-rotor vehicle can provide ground and air traffic congestion relief through direct, city center-to-city center service, economically transporting 30 passengers for distances of up to 600 miles. Additional commercial opportunities emerge in the JVX's servicing of offshore, remote and infrastructureless areas. It is noted that Alaska, more than any other American state, would benefit from the JVX's VTOL access to natural resources and otherwise isolated settlements. The civilian development of the JVX could lead to the development of commercial tilt rotor aircraft for other size classes.

  7. An integrated computer system for preliminary design of advanced aircraft.

    NASA Technical Reports Server (NTRS)

    Fulton, R. E.; Sobieszczanski, J.; Landrum, E. J.

    1972-01-01

    A progress report is given on the first phase of a research project to develop a system of Integrated Programs for Aerospace-Vehicle Design (IPAD) which is intended to automate to the largest extent possible the preliminary and detailed design of advanced aircraft. The approach used is to build a pilot system and simultaneously to carry out two major contractual studies to define a practical IPAD system preparatory to programing. The paper summarizes the specifications and goals of the IPAD system, the progress to date, and any conclusion reached regarding its feasibility and scope. Sample calculations obtained with the pilot system are given for aircraft preliminary designs optimized with respect to discipline parameters, such as weight or L/D, and these results are compared with designs optimized with respect to overall performance parameters, such as range or payload.

  8. Development of Stitched Composite Structure for Advanced Aircraft

    NASA Technical Reports Server (NTRS)

    Jegley, Dawn; Przekop, Adam; Rouse, Marshall; Lovejoy, Andrew; Velicki, Alex; Linton, Kim; Wu, Hsi-Yung; Baraja, Jaime; Thrash, Patrick; Hoffman, Krishna

    2015-01-01

    NASA has created the Environmentally Responsible Aviation Project to develop technologies which will reduce the impact of aviation on the environment. A critical aspect of this pursuit is the development of a lighter, more robust airframe that will enable the introduction of unconventional aircraft configurations. NASA and The Boeing Company are working together to develop a structural concept that is lightweight and an advancement beyond state-of-the-art composites. The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) is an integrally stiffened panel design where elements are stitched together and designed to maintain residual load-carrying capabilities under a variety of damage scenarios. With the PRSEUS concept, through-the-thickness stitches are applied through dry fabric prior to resin infusion, and replace fasteners throughout each integral panel. Through-the-thickness reinforcement at discontinuities, such as along flange edges, has been shown to suppress delamination and turn cracks, which expands the design space and leads to lighter designs. The pultruded rod provides stiffening away from the more vulnerable skin surface and improves bending stiffness. A series of building blocks were evaluated to explore the fundamental assumptions related to the capability and advantages of PRSEUS panels. These building blocks addressed tension, compression, and pressure loading conditions. The emphasis of the development work has been to assess the loading capability, damage arrestment features, repairability, post-buckling behavior, and response of PRSEUS flat panels to out-of plane pressure loading. The results of this building-block program from coupons through an 80%-scale pressure box have demonstrated the viability of a PRSEUS center body for the Hybrid Wing Body (HWB) transport aircraft. This development program shows that the PRSEUS benefits are also applicable to traditional tube-andwing aircraft, those of advanced configurations, and other

  9. Computerized life and reliability modelling for turboprop transmissions

    NASA Technical Reports Server (NTRS)

    Savage, M.; Radil, K. C.; Lewicki, D. G.; Coy, J. J.

    1988-01-01

    A generalized life and reliability model is presented for parallel shaft geared prop-fan and turboprop aircraft transmissions. The transmission life and reliability model is a combination of the individual reliability models for all the bearings and gears in the main load paths. The bearing and gear reliability models are based on classical fatigue theory and the two parameter Weibull failure distribution. A computer program was developed to calculate the transmission life and reliability. The program is modular. In its present form, the program can analyze five different transmission arrangements. However, the program can be modified easily to include additional transmission arrangements. An example is included which compares the life of a compound two-stage transmission with the life of a split-torque, parallel compound two-stage transmission as calculated by the comaputer program.

  10. Computerized life and reliability modelling for turboprop transmissions

    NASA Technical Reports Server (NTRS)

    Savage, M.; Radil, K. C.; Lewicki, D. G.; Coy, J. J.

    1988-01-01

    A generalized life and reliability model is presented for parallel shaft geared prop-fan and turboprop aircraft transmissions. The transmission life and reliability model is a combination of the individual reliability models for all the bearings and gears in the main load paths. The bearing and gear reliability models are based on classical fatigue theory and the two parameter Weibull failure distribution. A computer program was developed to calculate the transmission life and reliability. The program is modular. In its present form, the program can analyze five different transmission arrangements. However, the program can be modified easily to include additional transmission arrangements. An example is included which compares the life of a compound two-stage transmission with the life of a split-torque, parallel compound two-stage transmission, as calculated by the computer program.

  11. World commercial aircraft accidents

    SciTech Connect

    Kimura, C.Y.

    1993-01-01

    This report is a compilation of all accidents world-wide involving aircraft in commercial service which resulted in the loss of the airframe or one or more fatality, or both. This information has been gathered in order to present a complete inventory of commercial aircraft accidents. Events involving military action, sabotage, terrorist bombings, hijackings, suicides, and industrial ground accidents are included within this list. Included are: accidents involving world commercial jet aircraft, world commercial turboprop aircraft, world commercial pistonprop aircraft with four or more engines and world commercial pistonprop aircraft with two or three engines from 1946 to 1992. Each accident is presented with information in the following categories: date of the accident, airline and its flight numbers, type of flight, type of aircraft, aircraft registration number, construction number/manufacturers serial number, aircraft damage, accident flight phase, accident location, number of fatalities, number of occupants, cause, remarks, or description (brief) of the accident, and finally references used. The sixth chapter presents a summary of the world commercial aircraft accidents by major aircraft class (e.g. jet, turboprop, and pistonprop) and by flight phase. The seventh chapter presents several special studies including a list of world commercial aircraft accidents for all aircraft types with 100 or more fatalities in order of decreasing number of fatalities, a list of collision accidents involving commercial aircrafts, and a list of world commercial aircraft accidents for all aircraft types involving military action, sabotage, terrorist bombings, and hijackings.

  12. 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.

  13. Design of the advanced regional aircraft, the DART-75

    NASA Technical Reports Server (NTRS)

    Elliot, Steve; Gislason, Jason; Huffstetler, Mark; Mann, Jon; Withers, Ashley; Zimmerman, Mark

    1992-01-01

    The need for regional aircraft stems from the problem of hub airport congestion. Regional travel will allow a passenger to commute from one spoke city to another spoke city without entering the congested hub airport. In addition, those people traveling longer routes may begin the flight at home instead of traveling to the hub airport. At this time, there is no American aerospace company that produces a regional transport for under 100 passengers. The intention of the Developmental Advanced Regional Transport (DART-75) is to fill this void with a modern, efficient regional aircraft. This design achieves the efficiency through a number of advanced features including three lifting surfaces, partial composite construction, and an advanced engine design. Efficiency is not the only consideration. Structural integrity, fatigue life, ease of maintenance, passenger comfort and convenience, and environmental aspects must all be considered. These factors force the design team to face many tradeoffs that are studied to find the best solution. The final consideration that cannot be overlooked is that of cost. The DART-75 is a 75-passenger medium-range regional transport intended for spoke-to-spoke, spoke-to-hub, and some hub-to-hub operations. Included are the general descriptions of the structures, weight and balance, stability and control, performance, and engine design.

  14. Performance and benefits of an advanced technology supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Fitzsimmons, R. D.

    1976-01-01

    The results of four years research on technology are synthesized in an advanced supersonic cruise aircraft design. Comparisons are presented with the former United States SST and the British-French Concorde, including aerodynamic efficiency, propulsion efficiency, weight efficiency, and community noise. Selected trade study results are presented on the subjects of design cruise Mach number, engine cycle selection, and noise suppression. The critical issue of program timing is addressed and some observations made regarding the impact that timing has on engine selection and minimization of program risk.

  15. Advanced composite vertical stabilizer for DC-10 transport aircraft

    NASA Technical Reports Server (NTRS)

    Stephens, C. O.

    1979-01-01

    Structural design, tooling, fabrication, and test activities are reported for a program to develop an advanced composite vertical stabilizer (CVS) for the DC 10 Commercial Transport Aircraft. Structural design details are described and the status of structural and weight analyses are reported. A structural weight reduction of 21.7% is currently predicted. Test results are discussed for sine wave stiffened shear webs containing representative of the CVS spar webs and for lightning current transfer and tests on a panel representative of the CVS skins.

  16. Turboprop+: enhanced Turboprop diffusion-weighted imaging with a new phase correction.

    PubMed

    Lee, Chu-Yu; Li, Zhiqiang; Pipe, James G; Debbins, Josef P

    2013-08-01

    Faster periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion-weighted imaging acquisitions, such as Turboprop and X-prop, remain subject to phase errors inherent to a gradient echo readout, which ultimately limits the applied turbo factor (number of gradient echoes between each pair of radiofrequency refocusing pulses) and, thus, scan time reductions. This study introduces a new phase correction to Turboprop, called Turboprop+. This technique employs calibration blades, which generate 2-D phase error maps and are rotated in accordance with the data blades, to correct phase errors arising from off-resonance and system imperfections. The results demonstrate that with a small increase in scan time for collecting calibration blades, Turboprop+ had a superior immunity to the off-resonance-related artifacts when compared to standard Turboprop and recently proposed X-prop with the high turbo factor (turbo factor = 7). Thus, low specific absorption rate and short scan time can be achieved in Turboprop+ using a high turbo factor, whereas off-resonance related artifacts are minimized.

  17. Status of noise technology for advanced supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Stone, J. R.; Gutierrez, O. A.

    1980-01-01

    Developments in acoustic technology applicable to advanced supersonic cruise aircraft, particularly those which relate to jet noise and its suppression are reviewed. The noise reducing potential of high radius ratio, inverted velocity profile coannular jets is demonstrated by model scale results from a wide range of nozzle geometries, including some simulated flight cases. These results were verified statistically at large scale on a variable cycle engine (VCE) testbed. A preliminary assessment of potential VCE noise sources such as fan and core noise is made, based on the testbed data. Recent advances in the understanding of flight effects are reviewed. The status of component noise prediction methods is assessed on the basis of recent test data, and the remaining problem areas are outlined.

  18. 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.

  19. Composite Structure Modeling and Analysis of Advanced Aircraft Fuselage Concepts

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivek; Sorokach, Michael R.

    2015-01-01

    NASA Environmentally Responsible Aviation (ERA) project and the Boeing Company are collabrating to advance the unitized damage arresting composite airframe technology with application to the Hybrid-Wing-Body (HWB) aircraft. The testing of a HWB fuselage section with Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) construction is presently being conducted at NASA Langley. Based on lessons learned from previous HWB structural design studies, improved finite-element models (FEM) of the HWB multi-bay and bulkhead assembly are developed to evaluate the performance of the PRSEUS construction. In order to assess the comparative weight reduction benefits of the PRSEUS technology, conventional cylindrical skin-stringer-frame models of a cylindrical and a double-bubble section fuselage concepts are developed. Stress analysis with design cabin-pressure load and scenario based case studies are conducted for design improvement in each case. Alternate analysis with stitched composite hat-stringers and C-frames are also presented, in addition to the foam-core sandwich frame and pultruded rod-stringer construction. The FEM structural stress, strain and weights are computed and compared for relative weight/strength benefit assessment. The structural analysis and specific weight comparison of these stitched composite advanced aircraft fuselage concepts demonstrated that the pressurized HWB fuselage section assembly can be structurally as efficient as the conventional cylindrical fuselage section with composite stringer-frame and PRSEUS construction, and significantly better than the conventional aluminum construction and the double-bubble section concept.

  20. Applications of advanced V/STOL aircraft concepts to civil utility missions. Volume 2: Appendices

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The linear performance definition curves for the lift fan aircraft, tilt rotor aircraft, and advanced helicopter are given. The computer program written to perform the mission analysis for this study is also documented, and examples of its use are shown. Methods used to derive the performance coefficients for use in the mission analysis of the lift fan aircraft are described.

  1. The role of wind tunnel testing in the development of advanced rotary-wing aircraft

    NASA Technical Reports Server (NTRS)

    Kelly, M. W.

    1973-01-01

    The relations of wind tunnel test objectives to wind tunnel test requirements are reviewed in an assessment of the current role of wind tunnel testing in the development of advanced rotary-wing aircraft. Elements of typical development programs are examined, and a comparison of fixed wing and rotary wing aircraft programs is presented. Proposed new test facilities for fixed wing aircraft and typical aircraft program costs are discussed, along with the use of wind tunnels for tilt rotor research aircraft and the role of 40 x 80 ft wind tunnels in tilt rotor aircraft development. Some changes in current programs and methods are outlined for bringing about desired improvements.

  2. Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 5: Unsteady counterrotation ducted propfan analysis. Computer program user's manual

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Delaney, Robert A.; Adamczyk, John J.; Miller, Christopher J.; Arnone, Andrea; Swanson, Charles

    1993-01-01

    The primary objective of this study was the development of a time-marching three-dimensional Euler/Navier-Stokes aerodynamic analysis to predict steady and unsteady compressible transonic flows about ducted and unducted propfan propulsion systems employing multiple blade rows. The computer codes resulting from this study are referred to as ADPAC-AOACR (Advanced Ducted Propfan Analysis Codes-Angle of Attack Coupled Row). This report is intended to serve as a computer program user's manual for the ADPAC-AOACR codes developed under Task 5 of NASA Contract NAS3-25270, Unsteady Counterrotating Ducted Propfan Analysis. The ADPAC-AOACR program is based on a flexible multiple blocked grid discretization scheme permitting coupled 2-D/3-D mesh block solutions with application to a wide variety of geometries. For convenience, several standard mesh block structures are described for turbomachinery applications. Aerodynamic calculations are based on a four-stage Runge-Kutta time-marching finite volume solution technique with added numerical dissipation. Steady flow predictions are accelerated by a multigrid procedure. Numerical calculations are compared with experimental data for several test cases to demonstrate the utility of this approach for predicting the aerodynamics of modern turbomachinery configurations employing multiple blade rows.

  3. Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 2: Unsteady ducted propfan analysis computer program users manual

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Delaney, Robert A.; Bettner, James L.

    1991-01-01

    The primary objective of this study was the development of a time-dependent three-dimensional Euler/Navier-Stokes aerodynamic analysis to predict unsteady compressible transonic flows about ducted and unducted propfan propulsion systems at angle of attack. The computer codes resulting from this study are referred to as Advanced Ducted Propfan Analysis Codes (ADPAC). This report is intended to serve as a computer program user's manual for the ADPAC developed under Task 2 of NASA Contract NAS3-25270, Unsteady Ducted Propfan Analysis. Aerodynamic calculations were based on a four-stage Runge-Kutta time-marching finite volume solution technique with added numerical dissipation. A time-accurate implicit residual smoothing operator was utilized for unsteady flow predictions. For unducted propfans, a single H-type grid was used to discretize each blade passage of the complete propeller. For ducted propfans, a coupled system of five grid blocks utilizing an embedded C-grid about the cowl leading edge was used to discretize each blade passage. Grid systems were generated by a combined algebraic/elliptic algorithm developed specifically for ducted propfans. Numerical calculations were compared with experimental data for both ducted and unducted propfan flows. The solution scheme demonstrated efficiency and accuracy comparable with other schemes of this class.

  4. A fuel conservation study for transport aircraft utilizing advanced technology and hydrogen fuel

    NASA Technical Reports Server (NTRS)

    Berry, W.; Calleson, R.; Espil, J.; Quartero, C.; Swanson, E.

    1972-01-01

    The conservation of fossil fuels in commercial aviation was investigated. Four categories of aircraft were selected for investigation: (1) conventional, medium range, low take-off gross weight; (2) conventional, long range, high take-off gross weights; (3) large take-off gross weight aircraft that might find future applications using both conventional and advanced technology; and (4) advanced technology aircraft of the future powered with liquid hydrogen fuel. It is concluded that the hydrogen fueled aircraft can perform at reduced size and gross weight the same payload/range mission as conventionally fueled aircraft.

  5. Advances in aircraft design: Multiobjective optimization and a markup language

    NASA Astrophysics Data System (ADS)

    Deshpande, Shubhangi

    Today's modern aerospace systems exhibit strong interdisciplinary coupling and require a multidisciplinary, collaborative approach. Analysis methods that were once considered feasible only for advanced and detailed design are now available and even practical at the conceptual design stage. This changing philosophy for conducting conceptual design poses additional challenges beyond those encountered in a low fidelity design of aircraft. This thesis takes some steps towards bridging the gaps in existing technologies and advancing the state-of-the-art in aircraft design. The first part of the thesis proposes a new Pareto front approximation method for multiobjective optimization problems. The method employs a hybrid optimization approach using two derivative free direct search techniques, and is intended for solving blackbox simulation based multiobjective optimization problems with possibly nonsmooth functions where the analytical formof the objectives is not known and/or the evaluation of the objective function(s) is very expensive (very common in multidisciplinary design optimization). A new adaptive weighting scheme is proposed to convert a multiobjective optimization problem to a single objective optimization problem. Results show that the method achieves an arbitrarily close approximation to the Pareto front with a good collection of well-distributed nondominated points. The second part deals with the interdisciplinary data communication issues involved in a collaborative mutidisciplinary aircraft design environment. Efficient transfer, sharing, and manipulation of design and analysis data in a collaborative environment demands a formal structured representation of data. XML, a W3C recommendation, is one such standard concomitant with a number of powerful capabilities that alleviate interoperability issues. A compact, generic, and comprehensive XML schema for an aircraft design markup language (ADML) is proposed here to provide a common language for data

  6. Advanced electrical power system technology for the all electric aircraft

    NASA Technical Reports Server (NTRS)

    Finke, R. C.; Sundberg, G. R.

    1983-01-01

    The application of advanced electric power system technology to an all electric airplane results in an estimated reduction of the total takeoff gross weight of over 23,000 pounds for a large airplane. This will result in a 5 to 10 percent reduction in direct operating costs (DOC). Critical to this savings is the basic electrical power system component technology. These advanced electrical power components will provide a solid foundation for the materials, devices, circuits, and subsystems needed to satisfy the unique requirements of advanced all electric aircraft power systems. The program for the development of advanced electrical power component technology is described. The program is divided into five generic areas: semiconductor devices (transistors, thyristors, and diodes); conductors (materials and transmission lines); dielectrics; magnetic devices; and load management devices. Examples of progress in each of the five areas are discussed. Bipolar power transistors up to 1000 V at 100 A with a gain of 10 and a 0.5 microsec rise and fall time are presented. A class of semiconductor devices with a possibility of switching up to 100 kV is described. Solid state power controllers for load management at 120 to 1000 V and power levels to 25 kW were developed along with a 25 kW, 20 kHz transformer weighing only 3.2 kg.

  7. Advanced electrical power system technology for the all electric aircraft

    NASA Technical Reports Server (NTRS)

    Finke, R. C.; Sundberg, G. R.

    1983-01-01

    The application of advanced electric power system technology to an all electric airplane results in an estimated reduction of the total takeoff gross weight of over 23,000 pounds for a large airplane. This will result in a 5 to 10 percent reduction in direct operating costs (DOC). Critical to this savings is the basic electrical power system component technology. These advanced electrical power components will provide a solid foundation for the materials, devices, circuits, and subsystems needed to satisfy the unique requirements of advanced all electric aircraft power systems. The program for the development of advanced electrical power component technology is described. The program is divided into five generic areas: semiconductor devices (transistors, thyristors, and diodes); conductors (materials and transmission lines); dielectrics; magnetic devices; and load management devices. Examples of progress in each of the five areas are discussed. Bipolar power transistors up to 1000 V at 100 A with a gain of 10 and a 0.5 microsec rise and fall time are presented. A class of semiconductor devices with a possibility of switching up to 100 kV is described. Solid state power controllers for load management at 120 to 1000 V and power levels to 25 kW were developed along with a 25 kW, 20 kHz transformer weighing only 3.2 kg. Previously announced in STAR as N83-24764

  8. Unified aeroacoustics analysis for high speed turboprop aerodynamics and noise. Volume 2: Development of theory for wing shielding

    NASA Technical Reports Server (NTRS)

    Amiet, R. K.

    1991-01-01

    A unified theory for aerodynamics and noise of advanced turboprops is presented. The theory and a computer code developed for evaluation at the shielding benefits that might be expected by an aircraft wing in a wing-mounted propeller installation are presented. Several computed directivity patterns are presented to demonstrate the theory. Recently with the advent of the concept of using the wing of an aircraft for noise shielding, the case of diffraction by a surface in a flow has been given attention. The present analysis is based on the case of diffraction of no flow. By combining a Galilean and a Lorentz transform, the wave equation with a mean flow can be reduced to the ordinary equation. Allowance is also made in the analysis for the case of a swept wing. The same combination of Galilean and Lorentz transforms lead to a problem with no flow but a different sweep. The solution procedures for the cases of leading and trailing edges are basically the same. Two normalizations of the solution are given by the computer program. FORTRAN computer programs are presented with detailed documentation. The output from these programs compares favorably with the results of other investigators.

  9. Display-based communications for advanced transport aircraft

    NASA Technical Reports Server (NTRS)

    Lee, Alfred T.

    1989-01-01

    The next generation of civil transport aircraft will depend increasingly upon ground-air-ground and satellite data link for information critical to safe and efficient air transportation. Previous studies which examined the concept of display-based communications in addition to, or in lieu of, conventional voice transmissions are reviewed. A full-mission flight simulation comparing voice and display-based communication modes in an advanced transport aircraft is also described. The results indicate that a display-based mode of information transfer does not result in significantly increased aircrew workload, but does result in substantially increased message acknowledgment times when compared to conventional voice transmissions. User acceptance of the display-based communication system was generally high, replicating the findings of previous studies. However, most pilots tested expressed concern over the potential loss of information available from frequency monitoring which might result from the introduction of discrete address communications. Concern was expressed by some pilots for the reduced time available to search for conflicting traffic when using the communications display system. The implications of the findings for the design of display-based communications are discussed.

  10. Advanced Propulsion System Studies for General Aviation Aircraft

    NASA Technical Reports Server (NTRS)

    Eisenberg, Joseph D. (Technical Monitor); German, Jon

    2003-01-01

    This final report addresses the following topics: Market Impact Analysis (1) assessment of general aviation, including commuter/regional, aircraft market impact due to incorporation of advanced technology propulsion system on acquisition and operating costs, job creation and/or manpower demand, and future fleet size; (2) selecting an aircraft and engine for the study by focusing on the next generation 19-passenger commuter and the Williams International FJ44 turbofan engine growth. Propulsion System Analysis Conducted mission analysis studies and engine cycle analysis to define a new commuter mission and required engine performance, define acquisition and operating costs and, select engine configuration and initiated preliminary design for hardware modifications required. Propulsion System Benefits (1) assessed and defined engine emissions improvements, (2) assessed and defined noise reduction potential and, (3) conducted a cost analysis impact study. Review of Relevant NASA Programs Conducted literature searches using NERAC and NASA RECON services for related technology in the emissions and acoustics area. Preliminary Technology Development Plans Defined plan to incorporate technology improvements for an FJ44-2 growth engine in performance, emissions, and noise suppression.

  11. Recent Developments In Polycarbonate Coatings For Advanced Aircraft

    NASA Astrophysics Data System (ADS)

    Voss, D. L.; Raffo, J. A.

    1982-02-01

    Polycarbonate has emerged in recent years as the optimum choice of material for fabrication of advanced aircraft windshields and canopies that reauire maximum performance against bird strikes. This choice is based on a combination of properties of which the most outstanding are impact strength, high temperature resistance, light weight and ease of thermoforming to complex shapes. Polycarbonate, however, requires surface protection from abrasion, ultraviolet irradiation and common chemical solvents. The most cost-effective method of polycarbonate protection and one which adds negligible weight, is by the use of thin transparent polymeric coatings. This paper describes a coating which has been developed for aircraft applications and in fact meets the stringent requirements of the General Dynamics Lightweight F-16 specification. In order to withstand high-speed rain erosion and at the same time retain the mechanical properties of polycarbonate, it has been determined that inherent flexibility of the coating together with high adhesion to polycarbonate are essential requirements for long-term durability in service environments. The conceot of windshield surface protection, screening tests and shortcomings of other coatings will be reviewed emphasizing the major differences in performance between flexible and brittle formulations.

  12. Computerized structural mechanics for 1990's: Advanced aircraft needs

    NASA Technical Reports Server (NTRS)

    Viswanathan, A. V.; Backman, B. F.

    1989-01-01

    The needs for computerized structural mechanics (CSM) as seen from the standpoint of the aircraft industry are discussed. These needs are projected into the 1990's with special focus on the new advanced materials. Preliminary design/analysis, research, and detail design/analysis are identified as major areas. The role of local/global analyses in these different areas is discussed. The lessons learned in the past are used as a basis for the design of a CSM framework that could modify and consolidate existing technology and include future developments in a rational and useful way. A philosophy is stated, and a set of analyses needs driven by the emerging advanced composites is enumerated. The roles of NASA, the universities, and the industry are identified. Finally, a set of rational research targets is recommended based on both the new types of computers and the increased complexity the industry faces. Computerized structural mechanics should be more than new methods in structural mechanics and numerical analyses. It should be a set of engineering applications software products that combines innovations in structural mechanics, numerical analysis, data processing, search and display features, and recent hardware advances and is organized in a framework that directly supports the design process.

  13. Artificial intelligence for turboprop engine maintenance

    SciTech Connect

    1995-01-01

    Long-term maintenance operations, causing the unit to out of action, may seem economical - but they result in reduced operating readiness. Offsetting that concern, careless, hurried maintenance reduces margins of safety and reliability. Any tool that improves maintenance without causing a sharp increase in cost is valuable. Artificial intelligence (AI) is one of the tools. Expert system and neural networks are two different areas of AI that show promise for turboprop engine maintenance.

  14. A reappraisal of transport aircraft needs 1985 - 2000: Perceptions of airline management in a changing economic, regulatory, and technological environment

    NASA Technical Reports Server (NTRS)

    Spencer, F. A.

    1982-01-01

    Views of the executives of 24 major, national, regional, and commuter airlines concerning the effect of recent regulatory, economic, and technological changes on the roles they see for their airlines, and consequent changes in their plans for acquiring aircraft for the 1985 to 2000 period were surveyed. Differing perceptions on the economic justification for new-technology jets in the context of the carriers' present and projected financial conditions are outlined. After examining the cases for new or intermediate size jets, the study discusses turboprop powered transports, including the carriers' potential interest in an advanced technology, high-speed turboprop or prop-fan. Finally, the implications of foreign competition are examined in terms of each carrier's evaluation of the quality and financial offerings, as well as possible 'Buy American' policy predisposition.

  15. System design requirements for advanced rotary-wing agricultural aircraft

    NASA Technical Reports Server (NTRS)

    Lemont, H. E.

    1979-01-01

    Helicopter aerial dispersal systems were studied to ascertain constraints to the system, the effects of removal of limitations (technical and FAA regulations), and subsystem improvements. Productivity indices for the aircraft and swath effects were examined. Typical missions were formulated through conversations with operators, and differing gross weight aircraft were synthesized to perform these missions. Economic analysis of missions and aircraft indicated a general correlation of small aircraft (3000 lb gross weight) suitability for small fields (25 acres), and low dispersion rates (less than 32 lb/acre), with larger aircraft (12,000 lb gross weight) being more favorable for bigger fields (200 acres) and heavier dispersal rates (100 lb/acre). Operator problems, possible aircraft and system improvements, and selected removal of operating limitations were reviewed into recommendations for future NASA research items.

  16. Advanced Propulsion System Studies for General Aviation Aircraft

    NASA Technical Reports Server (NTRS)

    Eisenberg, Joseph D. (Technical Monitor); Elliott, Kathryn A.; Huebner, Steven R.

    2003-01-01

    In this study, new technology engines were defined in two power classes: a 200 hp class, for a light, 4-place personal aircraft, and a 1500 pound thrust class for a twin-engined, 6 place business jet type aircraft. The engines were evaluated for retrofitting suitable current production aircraft for comparison to the existing engines. The engines were evaluated for performance using a typical mission for each aircraft, as well as a variant mission to further appraise performance.Issues of cost, safety, maintenance, and reliability were also addressed. Manufacturing plans were then constructed.

  17. Advanced Propulsion Systems Study for General Aviation Aircraft

    NASA Technical Reports Server (NTRS)

    Mount, R.

    2003-01-01

    This study defines a family of advanced technology Stratified Charge Rotary Engines (SCRE) appropriate for the enablement of the development of a new generation of general aviation aircraft. High commonality, affordability, and environmental compatibility are considerations influencing the family composition and ratings. The SCRE family is comprised of three engines in the 70 Series (40 cu in. displacement per rotor), i.e. one, two, and four rotor and two engines in the 170 Series (105 cu in. displacement per rotor), i.e., two and four rotor. The two rotor engines are considered the primary engines in each series. A wide power range is considered covering 125 to 2500 HP through growth and compounding/dual pac considerations. Mission requirements, TBO, FAA Certification, engine development cycles, and costs are examined. Comparisons to current and projected reciprocating and turbine engine configurations in the 125 to 1000 HP class are provided. Market impact, estimated sales, and U.S. job creation (R&D, manufacturing and infractures) are examined.

  18. Advanced Low NOx Combustors for Aircraft Gas Turbines

    NASA Technical Reports Server (NTRS)

    Roberts, P. B.; White, D. J.; Shekleton, J. R.; Butze, H. F.

    1976-01-01

    A test rig program was conducted with the objective of evaluating and minimizing the exhaust emissions, in particular NOx, of two advanced aircraft combustor concepts at a simulated high-altitude cruise condition. The two pre-mixed, lean-reaction designs are known as the Jet Induced Circulation (JIC) combustor and the Vortex Air Blast (VAB) combustor and were rig tested in the form of reverse flow can combustors in the 0.13 ni (5.0 in. ) size range. Various configuration modifications were applied to the JIC and VAB combustor designs in an effort to reduce the emissions levels. The VAB combustor demonstrated a NOx level of 1.11 gm NO2/kg fuel with essentially 100 percent combustion efficiency at the simulated cruise combustor condition of 507 kPa (5 atm), 833 K (1500 R), inlet pressure and temperature respectively, and 1778 K (3200 R) outlet temperature on Jet-Al fuel. These configuration screening tests were carried out on essentially reaction zones only, in order to simplify the construction and modification of the combustors and to uncouple any possible effects on the emissions produced by the dilution flow. Tests were also conducted however at typical engine idle conditions on both combustors equipped with dilution ports in order to better define the problem areas involved in the operation of such concepts over a complete engine operational envelope. Versions of variable-geometry, JIC and VAB annular combustors are proposed.

  19. Advanced Study for Active Noise Control in Aircraft (ASANCA)

    NASA Technical Reports Server (NTRS)

    Borchers, Ingo U.; Emborg, Urban; Sollo, Antonio; Waterman, Elly H.; Paillard, Jacques; Larsen, Peter N.; Venet, Gerard; Goeransson, Peter; Martin, Vincent

    1992-01-01

    Aircraft interior noise and vibration measurements are included in this paper from ground and flight tests. In addition, related initial noise calculations with and without active noise control are conducted. The results obtained to date indicate that active noise control may be an effective means for reducing the critical low frequency aircraft noise.

  20. Resin transfer molding for advanced composite primary aircraft structures

    NASA Technical Reports Server (NTRS)

    Markus, Alan; Palmer, Ray

    1991-01-01

    Resin Transfer Molding (RTM) has been identified by Douglas Aircraft Company (DAC) and industry to be one of the promising processes being developed today which can break the cost barrier of implementing composite primary structures into a commercial aircraft production environment. The RTM process developments and scale-up plans Douglas Aircrart will be conducting under the NASA ACT contract are discussed.

  1. A study on the utilization of advanced composites in commercial aircraft wing structure: Executive summary

    NASA Technical Reports Server (NTRS)

    Watts, D. J.

    1978-01-01

    The overall wing study objectives are to study and plan the effort by commercial transport aircraft manufacturers to accomplish the transition from current conventional materials and practices to extensive use of advanced composites in wings of aircraft that will enter service in the 1985-1990 time period. Specific wing study objectives are to define the technology and data needed to support an aircraft manufacturer's commitment to utilize composites primary wing structure in future production aircraft and to develop plans for a composite wing technology program which will provide the needed technology and data.

  2. Design, cost, and advanced technology applications for a military trainer aircraft

    NASA Technical Reports Server (NTRS)

    Hill, G. C.; Harper, M.

    1975-01-01

    The potential impact is examined of advanced aerodynamic and propulsive technologies in terms of operating and acquisition costs on conceptual mission and performance requirements for a future undergraduate jet pilot trainer aircraft.

  3. Advanced aircraft service life monitoring method via flight-by-flight load spectra

    NASA Astrophysics Data System (ADS)

    Lee, Hongchul

    This research is an effort to understand current method and to propose an advanced method for Damage Tolerance Analysis (DTA) for the purpose of monitoring the aircraft service life. As one of tasks in the DTA, the current indirect Individual Aircraft Tracking (IAT) method for the F-16C/D Block 32 does not properly represent changes in flight usage severity affecting structural fatigue life. Therefore, an advanced aircraft service life monitoring method based on flight-by-flight load spectra is proposed and recommended for IAT program to track consumed fatigue life as an alternative to the current method which is based on the crack severity index (CSI) value. Damage Tolerance is one of aircraft design philosophies to ensure that aging aircrafts satisfy structural reliability in terms of fatigue failures throughout their service periods. IAT program, one of the most important tasks of DTA, is able to track potential structural crack growth at critical areas in the major airframe structural components of individual aircraft. The F-16C/D aircraft is equipped with a flight data recorder to monitor flight usage and provide the data to support structural load analysis. However, limited memory of flight data recorder allows user to monitor individual aircraft fatigue usage in terms of only the vertical inertia (NzW) data for calculating Crack Severity Index (CSI) value which defines the relative maneuver severity. Current IAT method for the F-16C/D Block 32 based on CSI value calculated from NzW is shown to be not accurate enough to monitor individual aircraft fatigue usage due to several problems. The proposed advanced aircraft service life monitoring method based on flight-by-flight load spectra is recommended as an improved method for the F-16C/D Block 32 aircraft. Flight-by-flight load spectra was generated from downloaded Crash Survival Flight Data Recorder (CSFDR) data by calculating loads for each time hack in selected flight data utilizing loads equations. From

  4. Seat Capacity Selection for an Advanced Short-Haul Aircraft Design

    NASA Technical Reports Server (NTRS)

    Marien, Ty V.

    2016-01-01

    A study was performed to determine the target seat capacity for a proposed advanced short-haul aircraft concept projected to enter the fleet by 2030. This analysis projected the potential demand in the U.S. for a short-haul aircraft using a transportation theory approach, rather than selecting a target seat capacity based on recent industry trends or current market demand. A transportation systems model was used to create a point-to-point network of short-haul trips and then predict the number of annual origin-destination trips on this network. Aircraft of varying seat capacities were used to meet the demand on this network, assuming a single aircraft type for the entire short-haul fleet. For each aircraft size, the ticket revenue and operational costs were used to calculate a total market profitability metric for all feasible flights. The different aircraft sizes were compared, based on this market profitability metric and also the total number of annual round trips and markets served. Sensitivity studies were also performed to determine the effect of changing the aircraft cruise speed and maximum trip length. Using this analysis, the advanced short-haul aircraft design team was able to select a target seat capacity for their design.

  5. Aircraft

    DOEpatents

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

    1998-09-22

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

  6. Aircraft

    DOEpatents

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

    1998-01-01

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

  7. Potential applications of advanced aircraft in developing countries

    NASA Technical Reports Server (NTRS)

    Maddalon, D. V.

    1978-01-01

    An investigation sponsored by NASA indicates that air transportation can play an important role in the economic progress of developing countries. By the turn of the century, the rapid economic growth now occurring in many developing countries should result in a major redistribution of the world's income. Some countries now classified as 'developing' will become 'developed' and are likely to become far more important to the world's civil aviation industry. Developing countries will be increasingly important buyers of conventional subsonic long-haul jet passenger aircraft but not to the point of significant influence on the design or technological content of future aircraft of this type. However, the technological content of more specialized aircraft may be influenced by developing country requirements and reflected in designs which fill a need concerning specialized missions, related to short-haul, low-density, rough runways, and natural resource development.

  8. Assessment of the application of advanced technologies to subsonic CTOL transport aircraft

    NASA Technical Reports Server (NTRS)

    Graef, J. D.; Sallee, G. P.; Verges, J. T.

    1974-01-01

    Design studies of the application of advanced technologies to future transport aircraft were conducted. These studies were reviewed from the perspective of an air carrier. A fundamental study of the elements of airplane operating cost was performed, and the advanced technologies were ranked in order of potential profit impact. Recommendations for future study areas are given.

  9. Application of advanced technologies to small, short-haul transport aircraft (STAT)

    NASA Technical Reports Server (NTRS)

    Kraus, E. F.; Mall, O. D.; Awker, R. W.; Scholl, J. W.

    1982-01-01

    The benefits of selected advanced technologies for 19 and 30 passenger, short-haul aircraft were identified. Advanced technologies were investigated in four areas: aerodynamics, propulsion, structures, and ride quality. Configuration sensitivity studies were conducted to show design tradeoffs associated with passenger capacity, cabin comfort level, and design field length.

  10. Some inadequacies of the current human factors certification process of advanced aircraft technologies

    NASA Technical Reports Server (NTRS)

    Paries, Jean

    1994-01-01

    Automation related accidents or serious incidents are not limited to advanced technology aircraft. There is a full history of such accidents with conventional technology aircraft. However, this type of occurrence is far from sparing the newest 'glass cockpit' generation, and it even seems to be a growing contributor to its accident rate. Nevertheless, all these aircraft have been properly certificated according to the relevant airworthiness regulations. Therefore, there is a growing concern that with the technological advancement of air transport aircraft cockpits, the current airworthiness regulations addressing cockpit design and human factors may have reached some level of inadequacy. This paper reviews some aspects of the current airworthiness regulations and certification process related to human factors of cockpit design and focuses on questioning their ability to guarantee the intended safety objectives.

  11. Systems study for an Integrated Digital-Electric Aircraft (IDEA)

    NASA Technical Reports Server (NTRS)

    Tagge, G. E.; Irish, L. A.; Bailey, A. R.

    1985-01-01

    The results of the Integrated Digital/Electric Aircraft (IDEA) Study are presented. Airplanes with advanced systems were, defined and evaluated, as a means of identifying potential high payoff research tasks. A baseline airplane was defined for comparison, typical of a 1990's airplane with advanced active controls, propulsion, aerodynamics, and structures technology. Trade studies led to definition of an IDEA airplane, with extensive digital systems and electric secondary power distribution. This airplane showed an improvement of 3% in fuel use and 1.8% in DOC relative to the baseline configuration. An alternate configuration, an advanced technology turboprop, was also evaluated, with greater improvement supported by digital electric systems. Recommended research programs were defined for high risk, high payoff areas appropriate for implementation under NASA leadership.

  12. 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.

  13. The AC-120: The advanced commercial transport

    NASA Technical Reports Server (NTRS)

    Duran, David; Griffin, Ernest; Mendoza, Saul; Nguyen, Son; Pickett, Tim; Noernberg, Clemm

    1993-01-01

    The main objective of this design was to fulfill a need for a new airplane to replace the aging 100 to 150 passenger, 1500 nautical mile range aircraft such as the Douglas DC9 and Boeing 737-100 airplanes. After researching the future aircraft market, conducting extensive trade studies, and analysis on different configurations, the AC-120 Advanced Commercial Transport final design was achieved. The AC-120's main design features include the incorporation of a three lifting surface configuration which is powered by two turboprop engines. The AC-120 is an economically sensitive aircraft which meets the new FM Stage Three noise requirements, and has lower NO(x) emissions than current turbofan powered airplanes. The AC-120 also improves on its contemporaries in passenger comfort, manufacturing, and operating cost.

  14. Aircraft noise source and computer programs - User's guide

    NASA Technical Reports Server (NTRS)

    Crowley, K. C.; Jaeger, M. A.; Meldrum, D. F.

    1973-01-01

    The application of computer programs for predicting the noise-time histories and noise contours for five types of aircraft is reported. The aircraft considered are: (1) turbojet, (2) turbofan, (3) turboprop, (4) V/STOL, and (5) helicopter. Three principle considerations incorporated in the design of the noise prediction program are core effectiveness, limited input, and variable output reporting.

  15. Advances in Fatigue and Fracture Mechanics Analyses for Metallic Aircraft Structures

    NASA Technical Reports Server (NTRS)

    Newman, J. C., Jr.

    2000-01-01

    This paper reviews some of the advances that have been made in stress analyses of cracked aircraft components, in the understanding of the fatigue and fatigue-crack growth process, and in the prediction of residual strength of complex aircraft structures with widespread fatigue damage. Finite-element analyses of cracked metallic structures are now used to determine accurate stress-intensity factors for cracks at structural details. Observations of small-crack behavior at open and rivet-loaded holes and the development of small-crack theory has lead to the prediction of stress-life behavior for components with stress concentrations under aircraft spectrum loading. Fatigue-crack growth under simulated aircraft spectra can now be predicted with the crack-closure concept. Residual strength of cracked panels with severe out-of-plane deformations (buckling) in the presence of stiffeners and multiple-site damage can be predicted with advanced elastic-plastic finite-element analyses and the critical crack-tip-opening angle (CTOA) fracture criterion. These advances are helping to assure continued safety of aircraft structures.

  16. The development and evaluation of advanced technology laminar-flow-control subsonic transport aircraft

    NASA Technical Reports Server (NTRS)

    Sturgeon, R. F.

    1978-01-01

    A study was conducted to evaluate the technical and economic feasibility of applying laminar flow control (LFC) to the wings and empennage of long-range subsonic transport aircraft for initial operation in 1985. For a design mission range of 5500 n mi, advanced technology LFC and turbulent-flow aircraft were developed for a 200-passenger payload, and compared on the basis of production costs, direct operating costs, and fuel efficiency. Parametric analyses were conducted to establish optimum geometry, advanced system concepts were evaluated, and configuration variations maximizing the effectiveness of LFC were developed. The final comparisons include consideation of maintenance costs and procedures, manufacturing costs and procedures, and operational considerations peculiar to LFC aircraft.

  17. Aircraft noise source and contour estimation

    NASA Technical Reports Server (NTRS)

    Dunn, D. G.; Peart, N. A.

    1973-01-01

    Calculation procedures are presented for predicting the noise-time histories and noise contours (footprints) of five basic types of aircraft; turbojet, turofan, turboprop, V/STOL, and helicopter. The procedures have been computerized to facilitate prediction of the noise characteristics during takeoffs, flyovers, and/or landing operations.

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

    NASA Technical Reports Server (NTRS)

    1975-01-01

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

  19. Variable stream control engine concept for advanced supersonic aircraft: Features and benefits

    NASA Technical Reports Server (NTRS)

    Howlett, R. A.

    1976-01-01

    The Variable Stream Control Engine is studied for advanced supersonic cruise aircraft. Significant environmental and performance improvements relative to first generation supersonic turbojet engines are cited. Two separate flow streams, each with independent burner and nozzle systems are incorporated within the engine. By unique control of the exhaust temperatures and velocities in two coannular streams, significant reduction in jet noise is obtained.

  20. Real-time application of advanced three-dimensional graphic techniques for research aircraft simulation

    NASA Technical Reports Server (NTRS)

    Davis, Steven B.

    1990-01-01

    Visual aids are valuable assets to engineers for design, demonstration, and evaluation. Discussed here are a variety of advanced three-dimensional graphic techniques used to enhance the displays of test aircraft dynamics. The new software's capabilities are examined and possible future uses are considered.

  1. Advanced composite fiber/metal pressure vessels for aircraft applications

    NASA Astrophysics Data System (ADS)

    Papanicolopoulos, Aleck

    1993-06-01

    Structural Composites Industries has developed, qualified, and delivered a number of high performance carbon epoxy overwrapped/seamless aluminum liner pressure vessels for use in military aircraft where low weight, low cost, high operating pressure and short lead time are the primary considerations. This paper describes product design, development, and qualification for a typical program. The vessel requirements included a munitions insensitivity criterion as evidenced by no fragmentation following impact by a .50 cal tumbling bullet. This was met by the development of a carbon-Spectra hybrid composite overwrap on a thin-walled seamless aluminum liner. The same manufacturing, inspection, and test processes that are used to produce lightweight, thin walled seamless aluminum lined carbon/epoxy overwrapped pressure vessels for satellite and other space applications were used to fabricate this vessel. This report focuses on the results of performance in the qualification testing.

  2. Fiber optic (flight quality) sensors for advanced aircraft propulsion

    NASA Technical Reports Server (NTRS)

    Poppel, Gary L.

    1994-01-01

    Development of flight prototype, fiber-optic sensing system components for measuring nine sensed parameters (three temperatures, two speeds, three positions, and one flame) on an F404-400 aircraft engine is described. Details of each sensor's design, functionality, and environmental testing, and the electro-optics architecture for sensor signal conditioning are presented. Eight different optical sensing techniques were utilized. Design, assembly, and environmental testing of an engine-mounted, electro-optics chassis unit (EOU), providing MIL-C-1553 data output, are related. Interconnection cables and connectors between the EOU and the sensors are identified. Results of sensor/cable/circuitry integrated testing, and installation and ground testing of the sensor system on an engine in October 1993 and April 1994 are given, including comparisons with the engine control system's electrical sensors. Lessons learned about the design, fabrication, testing, and integration of the sensor system components are included.

  3. Study of the application of advanced technologies to long range transport aircraft. Volume 2: Advanced technology program recommendations

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The benefits of the application of advanced technology to future transport aircraft were investigated. The noise reduction goals established by the CARD (Civil Aviation Research and Development) study for the 1981-1985 time period can be satisfied. Reduced terminal area and airway congestion can result from use of advanced on-board systems and operating procedures. The use of advanced structural design concepts can result in greatly reduced gross weight and improved operating economics. The full potential of these benefits can be realized in a 1985 airplane by implementing a research and development program that is funded to an average level of approximately $55 million per year over a ten year period.

  4. Propulsion. [NASA program for aircraft fuel consumption reduction

    NASA Technical Reports Server (NTRS)

    Nored, D. L.

    1978-01-01

    NASA aims at developing propulsion technology to reduce the fuel consumption of present engines by 5%, that of new engines of the late 1980s by at least 12%, and that of an advanced early 1990s turboprop by an additional 15%. This paper reviews three separate NASA programs which take up these aims. They are, respectively, Engine Component Improvement, Energy Efficient Engine, and Advanced Turboprops.

  5. 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.

  6. Evaluation of advanced lift concepts and fuel conservative short-haul aircraft, volume 1

    NASA Technical Reports Server (NTRS)

    Renshaw, J. H.; Bowden, M. K.; Narucki, C. W.; Bennett, J. A.; Smith, P. R.; Ferrill, R. S.; Randall, C. C.; Tibbetts, J. G.; Patterson, R. W.; Meyer, R. T.

    1974-01-01

    The performance and economics of a twin-engine augmentor wing airplane were evaluated in two phases. Design aspects of the over-the-wing/internally blown flap hybrid, augmentor wing, and mechanical flap aircraft were investigated for 910 m. field length with parametric extension to other field lengths. Fuel savings achievable by application of advanced lift concepts to short-haul aircraft were evaluated and the effect of different field lengths, cruise requirements, and noise levels on fuel consumption and airplane economics at higher fuel prices were determined. Conclusions and recommendations are presented.

  7. A study on the utilization of advanced composites in commercial aircraft wing structure

    NASA Technical Reports Server (NTRS)

    Watts, D. J.

    1978-01-01

    A study was conducted to define the technology and data needed to support the introduction of advanced composite materials in the wing structure of future production aircraft. The study accomplished the following: (1) definition of acceptance factors, (2) identification of technology issues, (3) evaluation of six candidate wing structures, (4) evaluation of five program options, (5) definition of a composite wing technology development plan, (6) identification of full-scale tests, (7) estimation of program costs for the total development plan, (8) forecast of future utilization of composites in commercial transport aircraft and (9) identification of critical technologies for timely program planning.

  8. Subsonic Ultra Green Aircraft Research Phase II: N+4 Advanced Concept Development

    NASA Technical Reports Server (NTRS)

    Bradley, Marty K.; Droney, Christopher K.

    2012-01-01

    This final report documents the work of the Boeing Subsonic Ultra Green Aircraft Research (SUGAR) team on Task 1 of the Phase II effort. The team consisted of Boeing Research and Technology, Boeing Commercial Airplanes, General Electric, and Georgia Tech. Using a quantitative workshop process, the following technologies, appropriate to aircraft operational in the N+4 2040 timeframe, were identified: Liquefied Natural Gas (LNG), Hydrogen, fuel cell hybrids, battery electric hybrids, Low Energy Nuclear (LENR), boundary layer ingestion propulsion (BLI), unducted fans and advanced propellers, and combinations. Technology development plans were developed.

  9. Design developments for advanced general aviation aircraft. [using Fly By Light Control

    NASA Technical Reports Server (NTRS)

    Roskam, Jan; Gomer, Charles

    1991-01-01

    Design study results are presented for two advanced general-aviation aircraft incorporating fly-by-light/fly-by-wire controls and digital avionics and cockpit displays. The design exercise proceeded from a database of information derived from a market survey for the 4-10 passenger aircraft range. Pusher and tractor propeller configurations were treated, and attention was given to the maximization of passenger comfort. 'Outside-in' tooling methods were assumed for the primary structures of both configurations, in order to achieve surface tolerances which maximize the rearward extent of laminar flow.

  10. Maneuver Performance Enhancement for an Advanced Fighter/Attack Aircraft

    NASA Technical Reports Server (NTRS)

    Samuels, Jeff; Langan, Kevin J.; Schmitz, Frederic H. (Technical Monitor)

    1994-01-01

    A small scale wind tunnel test of a realistic fighter configuration has been completed in NASA Ames' 7'x10' wind tunnel. This test was part of the Fighter Lift and Control (FLAC) program, a joint NASA - USAF research program, involving small and large-scale wind-tunnel tests and computational analysis of unique lift augmentation and control devices. The goal of this program is to enhance the maneuver and control capability of next-generation Air Force multi-role fighter aircraft with low-observables geometries. The principal objective of this test was to determine the effectiveness of passive boundary layer control devices at increasing L/D at sustained maneuver lift coefficients. Vortex generators (VGs) were used to energize the boundary layer to prevent or delay separation. Corotating vanes, counter-rotating vanes, and Wheeler Wishbone VGs were used in the vicinity of the leading and trailing edge flap hinge lines. Principle test parameters were leading and trailing edge flap deflections, and location, size, spacing, and orientation for each VG type. Gurney flaps were also tested. Data gathered include balance force and moment data, surface pressures, and flow visualization for characterizing flow behavior and locating separation lines. Results were quite different for the two best flap configurations tested. All VG types tested showed improvement (up to 5%) in maneuver L/D with flaps at LE=20 degrees, TE=0 degrees. The same VGs degraded performance, in all but a few cases, with flaps at LE=15 degrees, TE=10 degrees.

  11. Development of Advanced Methods of Structural and Trajectory Analysis for Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Ardema, Mark D.

    1996-01-01

    In this report the author describes: (1) development of advanced methods of structural weight estimation, and (2) development of advanced methods of flight path optimization. A method of estimating the load-bearing fuselage weight and wing weight of transport aircraft based on fundamental structural principles has been developed. This method of weight estimation represents a compromise between the rapid assessment of component weight using empirical methods based on actual weights of existing aircraft and detailed, but time-consuming, analysis using the finite element method. The method was applied to eight existing subsonic transports for validation and correlation. Integration of the resulting computer program, PDCYL, has been made into the weights-calculating module of the AirCraft SYNThesis (ACSYNT) computer program. ACSYNT bas traditionally used only empirical weight estimation methods; PDCYL adds to ACSYNT a rapid, accurate means of assessing the fuselage and wing weights of unconventional aircraft. PDCYL also allows flexibility in the choice of structural concept, as well as a direct means of determining the impact of advanced materials on structural weight.

  12. Advanced composite structural concepts and material technologies for primary aircraft structures

    NASA Technical Reports Server (NTRS)

    Jackson, Anthony

    1991-01-01

    Structural weight savings using advanced composites have been demonstrated for many years. Most military aircraft today use these materials extensively and Europe has taken the lead in their use in commercial aircraft primary structures. A major inhibiter to the use of advanced composites in the United States is cost. Material costs are high and will remain high relative to aluminum. The key therefore lies in the significant reduction in fabrication and assembly costs. The largest cost in most structures today is assembly. As part of the NASA Advanced Composite Technology Program, Lockheed Aeronautical Systems Company has a contract to explore and develop advanced structural and manufacturing concepts using advanced composites for transport aircraft. Wing and fuselage concepts and related trade studies are discussed. These concepts are intended to lower cost and weight through the use of innovative material forms, processes, structural configurations and minimization of parts. The approach to the trade studies and the downselect to the primary wing and fuselage concepts is detailed. The expectations for the development of these concepts is reviewed.

  13. Analysis of a Stretched Derivative Aircraft with Open Rotor Propulsion

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.; Hendricks, Eric S.; Haller, William J.; Guynn, Mark D.

    2015-01-01

    Research into advanced, high-speed civil turboprops received significant attention during the 1970s and 1980s when fuel efficiency was the driving focus of U.S. aeronautical research. But when fuel prices declined sharply there was no longer sufficient motivation to continue maturing the technology. Recent volatility in fuel prices and increasing concern for aviation's environmental impact, however, have renewed interest in unducted, open rotor propulsion and revived research by NASA and a number of engine manufacturers. Recently, NASA and General Electric have teamed to conduct several investigations into the performance and noise of an advanced, single-aisle transport with open rotor propulsion. The results of these initial studies indicate open rotor engines have the potential to provide significant reduction in fuel consumption compared to aircraft using turbofan engines with equivalent core technology. In addition, noise analysis of the concept indicates that an open rotor aircraft in the single-aisle transport class would be able to meet current noise regulations with margin. The behavior of derivative open rotor transports is of interest. Heavier, "stretched" derivative aircraft tend to be noisier than their lighter relatives. Of particular importance to the business case for the concept is how the noise margin changes relative to regulatory limits within a family of similar open rotor aircraft. The subject of this report is a performance and noise assessment of a notional, heavier, stretched derivative airplane equipped with throttle-push variants of NASA's initial open rotor engine design.

  14. Study on utilization of advanced composites in commercial aircraft wing structures. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    Sakata, I. F.; Ostrom, R. B.; Cardinale, S. V.

    1978-01-01

    The effort required by commercial transport manufacturers to accomplish the transition from current construction materials and practices to extensive use of composites in aircraft wings was investigated. The engineering and manufacturing disciplines which normally participate in the design, development, and production of an aircraft were employed to ensure that all of the factors that would enter a decision to commit to production of a composite wing structure were addressed. A conceptual design of an advanced technology reduced energy aircraft provided the framework for identifying and investigating unique design aspects. A plan development effort defined the essential technology needs and formulated approaches for effecting the required wing development. The wing development program plans, resource needs, and recommendations are summarized.

  15. Variable stream control engine for advanced supersonic aircraft design update

    NASA Technical Reports Server (NTRS)

    Hunt, R. B.; Howlett, R. A.

    1980-01-01

    The updating of the engine concept for a second-generation supersonic transport, the variable stream control engine (VSCE), in terms of mechanical design definition and estimated performance is discussed. The design definition reflects technology advancements that improve system efficiency, durability and environments were established. The components unique to the VSCE concept, a high performance duct burner and a low noise coannular nozzle, and the high temperature components are identified as critical technologies. Technology advances for the high temperature components (main combustor and turbines) are also discussed. To address the requirements in this area, the technical approach for undertaking a high temperature validation program is defined. The multi-phased effort would include assorted rig and laboratory tests, then culminate with the demonstration of a flight-type main combustor and single-stage high pressure turbine at operating conditions envisioned for a VSCE.

  16. Sensitivity of transport aircraft performance and economics to advanced technology and cruise Mach number

    NASA Technical Reports Server (NTRS)

    Ardema, M. D.

    1974-01-01

    Sensitivity data for advanced technology transports has been systematically collected. This data has been generated in two separate studies. In the first of these, three nominal, or base point, vehicles designed to cruise at Mach numbers .85, .93, and .98, respectively, were defined. The effects on performance and economics of perturbations to basic parameters in the areas of structures, aerodynamics, and propulsion were then determined. In all cases, aircraft were sized to meet the same payload and range as the nominals. This sensitivity data may be used to assess the relative effects of technology changes. The second study was an assessment of the effect of cruise Mach number. Three families of aircraft were investigated in the Mach number range 0.70 to 0.98: straight wing aircraft from 0.70 to 0.80; sweptwing, non-area ruled aircraft from 0.80 to 0.95; and area ruled aircraft from 0.90 to 0.98. At each Mach number, the values of wing loading, aspect ratio, and bypass ratio which resulted in minimum gross takeoff weight were used. As part of the Mach number study, an assessment of the effect of increased fuel costs was made.

  17. Some vortical-flow flight experiments on slender aircraft that impacted the advancement of aeronautics

    NASA Astrophysics Data System (ADS)

    Lamar, John E.

    2009-08-01

    This paper highlights the three aerodynamic pillars of aeronautics; namely, theory/CFD, wind-tunnel experiments and flight tests, and notes that at any given time these three are not necessarily at the same level of maturity. After an initial history of these three pillars, the focus narrows to a brief history of some vortical-flow flight experiments on slender aircraft that have impacted the advancement of aeronautics in recent decades. They include the F-106, Concorde, SR-71, light-weight fighters (F-16, F/A-18), and F-16XL. These aircraft share in common the utilization of vortical flow and have flown at transonic speeds during a part of the flight envelope. Due to the vast amount of information from flight and CFD that has recently become available for the F-16XL, this aircraft is highlighted and its results detailed. Lastly, it is interesting to note that, though complicated, vortical flows over the F-16XL aircraft at subsonic speeds can be reliably and generally well-predicted with the current CFD flow solvers. However, these solvers still have some problems in matching flight pressure data at transonic speeds. That this problem has been highlighted is both an advancement in aeronautics and a tempting prize to those who would seek its solution.

  18. 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.

  19. Advanced composite aileron for L-1011 transport aircraft

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Design and evaluation of alternate concepts for the major subcomponents of the advanced composite aileron (ACA) was completed. From this array of subcomponents, aileron assemblies were formulated and evaluated. Based on these analyses a multirib assembly with graphite tape/syntactic core covers, a graphite tape front spar, and a graphite fabric rib was selected for development. A weight savings of 29.1 percent (40.8 pounds per aileron) is predicted. Engineering cost analyses indicate that the production cost of the ACA will be 7.3 percent less than the current aluminum aileron. Fabrication, machining, and testing of the material evaluation specimens for the resin screening program was completed. The test results lead to the selection of Narmco 5208 resin for the ACA. Other activities completed include: the detailed design of the ACA, construction of a three dimensional finite element model for structural analysis, and formulation of detail plans for material verification and process development.

  20. Applications of advanced aerodynamic technology to light aircraft.

    NASA Technical Reports Server (NTRS)

    Crane, H. L.; Mcghee, R. J.; Kohlman, D. L.

    1973-01-01

    This paper discusses a project for adapting advanced technology, much of it borrowed from the jet transport, to general aviation design practice. The NASA funded portion of the work began in 1969 at the University of Kansas and resulted in a smaller, experimental wing with spoilers and powerful flap systems for a Cessna Cardinal airplane. Some flight data and research pilot comments are presented. The project was expanded in 1972 to include a light twin-engine airplane. For the twin there was the added incentive of a potential increase in single-engine climb performance. The use of a new high-lift Whitcomb airfoil is planned for both the wing and the propellers. Preliminary data on the characteristics of the new airfoil are discussed. The configuration of an experimental wing for a Piper Seneca PA-34 and estimated airplane performance with this wing are discussed.

  1. Advanced composite aileron for L-1011 transport aircraft: Aileron manufacture

    NASA Technical Reports Server (NTRS)

    Dunning, E. G.; Cobbs, W. L.; Legg, R. L.

    1981-01-01

    The fabrication activities of the Advanced Composite Aileron (ACA) program are discussed. These activities included detail fabrication, manufacturing development, assembly, repair and quality assurance. Five ship sets of ailerons were manufactured. The detail fabrication effort of ribs, spar and covers was accomplished on male tools to a common cure cycle. Graphite epoxy tape and fabric and syntactic epoxy materials were utilized in the fabrication. The ribs and spar were net cured and required no post cure trim. Material inconsistencies resulted in manufacturing development of the front spar during the production effort. The assembly effort was accomplished in subassembly and assembly fixtures. The manual drilling system utilized a dagger type drill in a hydraulic feed control hand drill. Coupon testing for each detail was done.

  2. Advanced technology payoffs for future rotorcraft, commuter aircraft, cruise missile, and APU propulsion systems

    NASA Technical Reports Server (NTRS)

    Turk, M. A.; Zeiner, P. K.

    1986-01-01

    In connection with the significant advances made regarding the performance of larger gas turbines, challenges arise concerning the improvement of small gas turbine engines in the 250 to 1000 horsepower range. In response to these challenges, the NASA/Army-sponsored Small Engine Component Technology (SECT) study was undertaken with the objective to identify the engine cycle, configuration, and component technology requirements for the substantial performance improvements desired in year-2000 small gas turbine engines. In the context of this objective, an American turbine engine company evaluated engines for four year-2000 applications, including a rotorcraft, a commuter aircraft, a supersonic cruise missile, and an auxiliary power unit (APU). Attention is given to reference missions, reference engines, reference aircraft, year-2000 technology projections, cycle studies, advanced engine selections, and a technology evaluation.

  3. Polymer, metal and ceramic matrix composites for advanced aircraft engine applications

    NASA Technical Reports Server (NTRS)

    Mcdanels, D. L.; Serafini, T. T.; Dicarlo, J. A.

    1985-01-01

    Advanced aircraft engine research within NASA Lewis is being focused on propulsion systems for subsonic, supersonic, and hypersonic aircraft. Each of these flight regimes requires different types of engines, but all require advanced materials to meet their goals of performance, thrust-to-weight ratio, and fuel efficiency. The high strength/weight and stiffness/weight properties of resin, metal, and ceramic matrix composites will play an increasingly key role in meeting these performance requirements. At NASA Lewis, research is ongoing to apply graphite/polyimide composites to engine components and to develop polymer matrices with higher operating temperature capabilities. Metal matrix composites, using magnesium, aluminum, titanium, and superalloy matrices, are being developed for application to static and rotating engine components, as well as for space applications, over a broad temperature range. Ceramic matrix composites are also being examined to increase the toughness and reliability of ceramics for application to high-temperature engine structures and components.

  4. Polymer, metal, and ceramic matrix composites for advanced aircraft engine applications

    SciTech Connect

    Mc Daniels, D.L.; Serafini, T.T.; Di Carlo, J.A.

    1986-06-01

    Advanced aircraft engine research within NASA Lewis focuses on propulsion systems for subsonic, supersonic, and hypersonic aircraft. Each of these flight regimes requires different types of engines, but all require advanced materials to meet their goals of performance, thrust-to-weight ratio, and fuel efficiency. The high strength/weight and stiffness/weight properties of resin, metal, and ceramic matrix composites will play an increasingly key role in meeting these performance requirements. At NASA Lewis, research is ongoing to apply graphite/polyimide composites to engine components and to develop polymer matrices with higher operating temperature capabilities. Metal matrix composites, using magnesium, aluminum, titanium, and superalloy matrices, are being developed for application to static and rotating engine components, as well as for space applications, over a broad temperature range. Ceramic matrix composites are also being examined to increase the toughness and reliability of ceramics for application to high-temperature engine structures and components.

  5. Multiplexing electro-optic architectures for advanced aircraft integrated flight control systems

    NASA Technical Reports Server (NTRS)

    Seal, D. W.

    1989-01-01

    This report describes the results of a 10 month program sponsored by NASA. The objective of this program was to evaluate various optical sensor modulation technologies and to design an optimal Electro-Optic Architecture (EOA) for servicing remote clusters of sensors and actuators in advanced aircraft flight control systems. The EOA's supply optical power to remote sensors and actuators, process the modulated optical signals returned from the sensors, and produce conditioned electrical signals acceptable for use by a digital flight control computer or Vehicle Management System (VMS) computer. This study was part of a multi-year initiative under the Fiber Optic Control System Integration (FOCSI) program to design, develop, and test a totally integrated fiber optic flight/propulsion control system for application to advanced aircraft. Unlike earlier FOCSI studies, this program concentrated on the design of the EOA interface rather than the optical transducer technology itself.

  6. Advanced composite elevator for Boeing 727 aircraft. Volume 1: Technical summary

    NASA Technical Reports Server (NTRS)

    Chovil, D. V.; Harvey, S. T.; Mccarty, J. E.; Desper, O. E.; Jamison, E. S.; Syder, H.

    1981-01-01

    The design, development, analysis, and testing activities and results that were required to produce five and one-half shipsets of advanced composite elevators for Boeing 727 aircraft are summarized. During the preliminary design period, alternative concepts were developed. After selection of the best design, detail design and basic configuration improvements were evaluated. Five and one-half shipsets were manufactured. All program goals (except competitive cost demonstration) were accomplished when our design met or exceeded all requirements, criteria, and objectives.

  7. Profile design for an advanced-technology airfoil for general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Welte, D.

    1978-01-01

    A profile from the NASA General Aviation Whitcomb series and NACA profiles are used as a starting point in designing an advanced airfoil for general aviation aircraft. Potential theory pressure distribution calculations, together with boundary layer calculations, permit a decrease in the null moment and an optimization of the lift characteristics of the wing. Trailing edge flap design is also improved. Wind tunnel tests are used to compare the conventional profiles, the NASA profile, and the improved design.

  8. An evaluation of descent strategies for TNAV-equipped aircraft in an advanced metering environment

    NASA Technical Reports Server (NTRS)

    Izumi, K. H.; Schwab, R. W.; Groce, J. L.; Coote, M. A.

    1986-01-01

    Investigated were the effects on system throughput and fleet fuel usage of arrival aircraft utilizing three 4D RNAV descent strategies (cost optimal, clean-idle Mach/CAS and constant descent angle Mach/CAS), both individually and in combination, in an advanced air traffic control metering environment. Results are presented for all mixtures of arrival traffic consisting of three Boeing commercial jet types and for all combinations of the three descent strategies for a typical en route metering airport arrival distribution.

  9. Demonstration Advanced Avionics System (DAAS) functional description. [Cessna 402B aircraft

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A comprehensive set of general aviation avionics were defined for integration into an advanced hardware mechanization for demonstration in a Cessna 402B aircraft. Block diagrams are shown and system and computer architecture as well as significant hardware elements are described. The multifunction integrated data control center and electronic horizontal situation indicator are discussed. The functions that the DAAS will perform are examined. This function definition is the basis for the DAAS hardware and software design.

  10. The next generation in aircraft protection against advanced MANPADS

    NASA Astrophysics Data System (ADS)

    Chapman, Stuart

    2014-10-01

    This paper discusses the advanced and novel technologies and underlying systems capabilities that Selex ES has applied during the development, test and evaluation of the twin head Miysis DIRCM System in order to ensure that it provides the requisite levels of protection against the latest, sophisticated all-aspect IR MANPADS. The importance of key performance parameters, including the fundamental need for "spherical" coverage, rapid time to energy-on-target, laser tracking performance and radiant intensity on seeker dome is covered. It also addresses the approach necessary to ensure that the equipment is suited to all air platforms from the smallest helicopters to large transports, while also ensuring that it achieves an inherent high reliability and an ease of manufacture and repair such that a step change in through-life cost in comparison to previous generation systems can be achieved. The benefits and issues associated with open architecture design are also considered. Finally, the need for extensive test and evaluation at every stage, including simulation, laboratory testing, platform and target dynamic testing in a System Integration Laboratory (SIL), flight trial, missile live-fire, environmental testing and reliability testing is also described.

  11. Full-scale testing, production and cost analysis data for the advanced composite stabilizer for Boeing 737 aircraft, volume 2

    NASA Technical Reports Server (NTRS)

    Aniversario, R. B.; Harvey, S. T.; Mccarty, J. E.; Parson, J. T.; Peterson, D. C.; Pritchett, L. D.; Wilson, D. R.; Wogulis, E. R.

    1982-01-01

    The development, testing, production activities, and associated costs that were required to produce five-and-one-half advanced-composite stabilizer shipsets for Boeing 737 aircraft are defined and discussed.

  12. Cost benefit study of advanced materials technology for aircraft turbine engines

    NASA Technical Reports Server (NTRS)

    Hillery, R. V.; Johnston, R. P.

    1977-01-01

    The cost/benefits of eight advanced materials technologies were evaluated for two aircraft missions. The overall study was based on a time frame of commercial engine use of the advanced material technologies by 1985. The material technologies evaluated were eutectic turbine blades, titanium aluminide components, ceramic vanes, shrouds and combustor liners, tungsten composite FeCrAly blades, gamma prime oxide dispersion strengthened (ODS) alloy blades, and no coat ODS alloy combustor liners. They were evaluated in two conventional takeoff and landing missions, one transcontinental and one intercontinental.

  13. Preliminary simulation of an advanced, hingless rotor XV-15 tilt-rotor aircraft

    NASA Technical Reports Server (NTRS)

    Mcveigh, M. A.

    1976-01-01

    The feasibility of the tilt-rotor concept was verified through investigation of the performance, stability and handling qualities of the XV-15 tilt rotor. The rotors were replaced by advanced-technology fiberglass/composite hingless rotors of larger diameter, combined with an advanced integrated fly-by-wire control system. A parametric simulation model of the HRXV-15 was developed, model was used to define acceptable preliminary ranges of primary and secondary control schedules as functions of the flight parameters, to evaluate performance, flying qualities and structural loads, and to have a Boeing-Vertol pilot conduct a simulated flight test evaluation of the aircraft.

  14. Aircraft energy efficiency. Overview

    NASA Technical Reports Server (NTRS)

    1981-01-01

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

  15. World commercial aircraft accidents. Second edition, 1946--1992

    SciTech Connect

    Kimura, C.Y.

    1993-01-01

    This report is a compilation of all accidents world-wide involving aircraft in commercial service which resulted in the loss of the airframe or one or more fatality, or both. This information has been gathered in order to present a complete inventory of commercial aircraft accidents. Events involving military action, sabotage, terrorist bombings, hijackings, suicides, and industrial ground accidents are included within this list. Included are: accidents involving world commercial jet aircraft, world commercial turboprop aircraft, world commercial pistonprop aircraft with four or more engines and world commercial pistonprop aircraft with two or three engines from 1946 to 1992. Each accident is presented with information in the following categories: date of the accident, airline and its flight numbers, type of flight, type of aircraft, aircraft registration number, construction number/manufacturers serial number, aircraft damage, accident flight phase, accident location, number of fatalities, number of occupants, cause, remarks, or description (brief) of the accident, and finally references used. The sixth chapter presents a summary of the world commercial aircraft accidents by major aircraft class (e.g. jet, turboprop, and pistonprop) and by flight phase. The seventh chapter presents several special studies including a list of world commercial aircraft accidents for all aircraft types with 100 or more fatalities in order of decreasing number of fatalities, a list of collision accidents involving commercial aircrafts, and a list of world commercial aircraft accidents for all aircraft types involving military action, sabotage, terrorist bombings, and hijackings.

  16. A parametric determination of transport aircraft price

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1975-01-01

    Cost per unit weight and other airframe and engine cost relations are given. Power equations representing these relations are presented for six airplane groups: general aircraft, turboprop transports, small jet transports, conventional jet transports, wide-body transports, supersonic transports, and for reciprocating, turboshaft, and turbothrust engines. Market prices calculated for a number of aircraft by use of the equations together with the aircraft characteristics are in reasonably good agreement with actual prices. Such price analyses are of value in the assessment of new aircraft devices and designs and potential research and development programs.

  17. Lateral noise attenuation of the advanced propeller of the propfan test assessment aircraft

    NASA Technical Reports Server (NTRS)

    Chambers, F. W.; Reddy, N. N.; Bartel, H. W.

    1989-01-01

    Lateral noise attenuation characteristics of the advanced propeller are determined using the flight test results of the testbed aircraft, Propfan Test Assessment (PTA), with a single, large-scale propfan. The acoustic data were obtained with an array of ground-mounted microphones positioned at distances up to 2.47 km (8100 feet) to the side of the flight path. The aircraft was flown at a Mach number of 0.31 for a variety of operating conditions. The lateral noise attenuation in a frequency range containing the blade passage frequency of the propeller was found to have positive magnitudes on the propfan side and negative magnitudes on the opposite side. The measured attenuation exhibits a strong dependence upon the elevation angle. The results also display a clear dependence upon the angle at which the propeller and nacelle are mounted on the wing (inflow angle).

  18. Study of advanced fuel system concepts for commercial aircraft and engines

    NASA Technical Reports Server (NTRS)

    Versaw, E. F.; Brewer, G. D.; Byers, W. D.; Fogg, H. W.; Hanks, D. E.; Chirivella, J.

    1983-01-01

    The impact on a commercial transport aircraft of using fuels which have relaxed property limits relative to current commercial jet fuel was assessed. The methodology of the study is outlined, fuel properties are discussed, and the effect of the relaxation of fuel properties analyzed. Advanced fuel system component designs that permit the satisfactory use of fuel with the candidate relaxed properties in the subject aircraft are described. The two fuel properties considered in detail are freezing point and thermal stability. Three candidate fuel system concepts were selected and evaluated in terms of performance, cost, weight, safety, and maintainability. A fuel system that incorporates insulation and electrical heating elements on fuel tank lower surfaces was found to be most cost effective for the long term.

  19. A Psychoacoustic Evaluation of Noise Signatures from Advanced Civil Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Rizzi, Stephen A.; Christian, Andrew

    2016-01-01

    The NASA Environmentally Responsible Aviation project has been successful in developing and demonstrating technologies for integrated aircraft systems that can simultaneously meet aggressive goals for fuel burn, noise and emissions. Some of the resulting systems substantially differ from the familiar tube and wing designs constituting the current civil transport fleet. This study attempts to explore whether or not the effective perceived noise level metric used in the NASA noise goal accurately reflects human subject response across the range of vehicles considered. Further, it seeks to determine, in a quantitative manner, if the sounds associated with the advanced aircraft are more or less preferable to the reference vehicles beyond any differences revealed by the metric. These explorations are made through psychoacoustic tests in a controlled laboratory environment using simulated stimuli developed from auralizations of selected vehicles based on systems noise assessments.

  20. Computer program to predict noise of general aviation aircraft: User's guide

    NASA Technical Reports Server (NTRS)

    Mitchell, J. A.; Barton, C. K.; Kisner, L. S.; Lyon, C. A.

    1982-01-01

    Program NOISE predicts General Aviation Aircraft far-field noise levels at FAA FAR Part 36 certification conditions. It will also predict near-field and cabin noise levels for turboprop aircraft and static engine component far-field noise levels.

  1. Advanced Methods for Acoustic and Thrust Benefits for Aircraft Engine Nozzles

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    The Fluid Mechanics and Acoustics Laboratory (FM&AL) was established At Hampton University in June of 1996. In addition, the FM&AL jointly conducted research with the Central AeroHydrodynamics Institute (TsAGI, Moscow) in Russia under a 2.5 year Civilian Research and Development Foundation (CRDF). The goals of the FM&AL programs are two fold: 1) to improve the working efficiency of the FM&AL team in generating new innovative ideas and in conducting research in the field of fluid dynamics and acoustics, basically for improvement of supersonic and subsonic aircraft engines, and 2) to attract promising minority students to this research and training and, in cooperation with other HU departments, to teach them basic knowledge in Aerodynamics, Gas Dynamics, and Theoretical and Experimental Methods in Aeroacoustics and Computational Fluid Dynamics (CFD). The research at the FM&AL supports reduction schemes associated with the emission of engine pollutants for commercial aircraft and concepts for reduction of observables for military aircraft. These research endeavors relate to the goals of the NASA Strategic Enterprise in Aeronautics concerning the development of environmentally acceptable aircraft. It is in this precise area, where the US aircraft industry, academia, and Government are in great need of trained professionals and which is a high priority goal of the Minority University Research and Education (MUREP) Program, that the HU FM&AL can make its most important contribution. This project already benefits NASA and HU because: First, the innovation, testing, and further development of new techniques for advanced propulsion systems are necessary for the successful attainment of the NASA Long Term Goals in Aeronautics and Space Transportation Technology (ASTT) including Global Civil Aviation, Revolutionary Technology Leaps, Access to Space, R&D Services, and the economic competitiveness of the US Aircraft Industry in the 2 1 st century. Secondly, the joint

  2. Scaling aircraft noise perception.

    NASA Technical Reports Server (NTRS)

    Ollerhead, J. B.

    1973-01-01

    Following a brief review of the background to the study, an extensive experiment is described which was undertaken to assess the practical differences between numerous alternative methods for calculating the perceived levels of individual aircraft flyover wounds. One hundred and twenty recorded sounds, including jets, turboprops, piston aircraft and helicopters were rated by a panel of subjects in a pair comparison test. The results were analyzed to evaluate a number of noise rating procedures, in terms of their ability to accurately estimate both relative and absolute perceived noise levels over a wider dynamic range (84-115 dB SPL) than had generally been used in previous experiments. Performances of the different scales were examined in detail for different aircraft categories, and the merits of different band level summation procedures, frequency weighting functions, duration and tone corrections were investigated.

  3. CFD analysis of turboprop engine oil cooler duct for best rate of climb condition

    NASA Astrophysics Data System (ADS)

    Kalia, Saurabh; CA, Vinay; Hegde, Suresh M.

    2016-09-01

    Turboprop engines are widely used in commuter category airplanes. Aircraft Design bureaus routinely conduct the flight tests to confirm the performance of the system. The lubrication system of the engine is designed to provide a constant supply of clean lubrication oil to the engine bearings, the reduction gears, the torque-meter, the propeller and the accessory gearbox. The oil lubricates, cools and also conducts foreign material to the oil filter where it is removed from further circulation. Thus a means of cooling the engine oil must be provided and a suitable oil cooler (OC) and ducting system was selected and designed for this purpose. In this context, it is relevant to study and analyse behaviour of the engine oil cooler system before commencing actual flight tests. In this paper, the performance of the oil cooler duct with twin flush NACA inlet housed inside the nacelle has been studied for aircraft best rate of climb (ROC) condition using RANS based SST K-omega model by commercial software ANSYS Fluent 13.0. From the CFD analysis results, it is found that the mass flow rate captured and pressure drop across the oil cooler for the best ROC condition is meeting the oil cooler manufacturer requirements thus, the engine oil temperature is maintained within prescribed limits.

  4. Effect of aircraft technology improvements on intercity energy use

    NASA Technical Reports Server (NTRS)

    1976-01-01

    An examination of the growth or decline in energy consumption in short haul, high density intercity transportation is made in relation to changes in aeronautical technology. Improvements or changes in the technology of competitive modes are also included. Certain improvements in air traffic control procedures were included to determine their effectiveness in saving energy along with a fuel efficient turboprop short haul aircraft concept.

  5. Lessons learned from pilot errors using automated systems in advanced technology aircraft

    SciTech Connect

    Nelson, W.R.; Byers, J.C.; Haney, L.N.; Ostrom, L.T.; Reece, W.J.

    1993-01-01

    The National Aeronautics and Space Administration (NASA) sponsored a project at the Idaho National Engineering Laboratory (INEL) to investigate pilot errors that occur during interaction with automated systems in advanced technology ( glass cockpit'') aircraft. In particular, we investigated the causes and potential corrective measures for pilot errors that resulted in altitude deviation incidents (i.e. failure to capture or maintain the altitude assigned by air traffic control). To do this, we analyzed altitude deviation events that have been reported in the Aviation Safety Reporting System (ASRS), NASA's data base of incidents self-reported by pilots and air traffic controllers. We developed models of the pilot tasks that are performed to capture and maintain altitude. Two types of models were developed to provide complementary perspectives of these tasks: sequential models and functional models. Both types of models show the errors that occur in actual altitude deviation events in advanced technology aircraft. Then, errors from the ASRS data base were categorized according to the models, to help understand the potential causes of the different error types. This paper summarizes the methodology used to analyze pilot errors, the lessons learned from the study of altitude deviation errors, and the application of these results for the introduction of advanced technology in nuclear power plants.

  6. Lessons learned from pilot errors using automated systems in advanced technology aircraft

    SciTech Connect

    Nelson, W.R.; Byers, J.C.; Haney, L.N.; Ostrom, L.T.; Reece, W.J.

    1993-04-01

    The National Aeronautics and Space Administration (NASA) sponsored a project at the Idaho National Engineering Laboratory (INEL) to investigate pilot errors that occur during interaction with automated systems in advanced technology (``glass cockpit``) aircraft. In particular, we investigated the causes and potential corrective measures for pilot errors that resulted in altitude deviation incidents (i.e. failure to capture or maintain the altitude assigned by air traffic control). To do this, we analyzed altitude deviation events that have been reported in the Aviation Safety Reporting System (ASRS), NASA`s data base of incidents self-reported by pilots and air traffic controllers. We developed models of the pilot tasks that are performed to capture and maintain altitude. Two types of models were developed to provide complementary perspectives of these tasks: sequential models and functional models. Both types of models show the errors that occur in actual altitude deviation events in advanced technology aircraft. Then, errors from the ASRS data base were categorized according to the models, to help understand the potential causes of the different error types. This paper summarizes the methodology used to analyze pilot errors, the lessons learned from the study of altitude deviation errors, and the application of these results for the introduction of advanced technology in nuclear power plants.

  7. System design and integration of the large-scale advanced prop-fan

    NASA Technical Reports Server (NTRS)

    Huth, B. P.

    1986-01-01

    In recent years, considerable attention has been directed toward improving aircraft fuel consumption. Studies have shown that blades with thin airfoils and aerodynamic sweep extend the inherent efficiency advantage that turboprop propulsion systems have demonstrated to the higher speed to today's aircraft. Hamilton Standard has designed a 9-foot diameter single-rotation Prop-Fan. It will test the hardware on a static test stand, in low speed and high speed wind tunnels and on a research aircraft. The major objective of this testing is to establish the structural integrity of large scale Prop-Fans of advanced construction, in addition to the evaluation of aerodynamic performance and the aeroacoustic design. The coordination efforts performed to ensure smooth operation and assembly of the Prop-Fan are summarized. A summary of the loads used to size the system components, the methodology used to establish material allowables and a review of the key analytical results are given.

  8. In-flight source noise of an advanced full-scale single-rotation propeller

    NASA Technical Reports Server (NTRS)

    Woodward, Richard P.; Loffler, Irvin J.

    1991-01-01

    Flight tests to define the far-field tone source at cruise conditions have been completed on the full-scale SR-7L advanced turboprop, which was installed on the left wing of a Gulfstream II aircraft. These measurements defined source levels for input into long-distance propagation models to predict en route noise. Infight data were taken for seven test cases. The sideline directivities measured showed expected maximum levels near 105 deg from the propeller upstream axis. However, azimuthal directivities based on the maximum observed sideline tone levels showed highest levels below the aircraft. The tone level reduction associated with reductions in propeller tip speed is shown to be more significant in the horizontal plane than below the aircraft.

  9. Application of an advanced computerized structural design system to an arrow-wing supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Robinson, J. C.; Yates, E. C., Jr.; Turner, M. J.; Grande, D. L.

    1975-01-01

    A structural design study of an arrow-wing supersonic cruise aircraft has been made using the integrated design system, ATLAS, and a relatively large analytical finite-element model containing 8500 degrees of freedom. This paper focuses on structural design methods developed and used in support of the study with emphasis on aeroelasticity. The use of ATLAS permitted (1) automatic resizing of the wing structure for multiple load conditions, (2) rapid evaluation of aeroelastic effects, and (3) an iterative approach to the correction of flutter deficiencies. The significant results of the study are discussed along with the advantages derived from the use of an advanced structural design system in preliminary design studies.

  10. The new low nitrogen steel LNS -- A material for advanced aircraft engine and aerospace bearing applications

    SciTech Connect

    Berns, H.; Ebert, F.J.

    1998-12-31

    Development tendencies for future aircraft jet engines require new design concepts for rolling element bearings because of an overall increase of loads, temperatures, rotational speeds and the use of new high temperature lubricants. This paper reviews some of the key parameters which in the past led to the development and application of the known aircraft bearing steels such as M50, M50 NiL and recently Cronidur 30{reg_sign} (AMS 5898). The performance limits of the currently used aerospace bearing steels and the increasing demands on bearing performance for future aerospace applications gave the impact to the design of a new corrosion resistant steel grade of the nitrogen alloyed type, which is suitable for case hardening by nitrogen--the so called Low nitrogen steel (LNS). The development of the alloy (US pat. 5,503,797), the attainable properties and the corresponding heat treatment process are presented. Achievable hardness, case depth, residual stress pattern and corrosion resistance prove the new LNS to be a promising candidate for the next generation of aircraft engine bearings and for advanced, integrated bearing-gear-shaft design concepts.

  11. Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations

    NASA Astrophysics Data System (ADS)

    Ryder, C. L.; McQuaid, J. B.; Flamant, C.; Washington, R.; Brindley, H. E.; Highwood, E. J.; Marsham, J. H.; Parker, D. J.; Todd, M. C.; Banks, J. R.; Brooke, J. K.; Engelstaedter, S.; Estellés, V.; Formenti, P.; Garcia-Carreras, L.; Kocha, C.; Marenco, F.; Rosenberg, P.; Sodemann, H.; Allen, C. J. T.; Bourdon, A.; Bart, M.; Cavazos-Guerra, C.; Chevaillier, S.; Crosier, J.; Darbyshire, E.; Dean, A. R.; Dorsey, J. R.; Kent, J.; O'Sullivan, D.; Schepanski, K.; Szpek, K.; Woolley, A.

    2015-01-01

    The Fennec climate program aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes they have provided. Aircraft instrumentation aboard the UK FAAM BAe146 and French SAFIRE Falcon 20 is described, with specific focus on instrumentation specially developed and relevant to Saharan meteorology and dust. Flight locations, aims and associated meteorology are described. Examples and applications of aircraft measurements from the Fennec flights are presented, highlighting new scientific results delivered using a synergy of different instruments and aircraft. These include: (1) the first airborne measurement of dust particles sized up to 300 microns and associated dust fluxes in the Saharan atmospheric boundary layer (SABL), (2) dust uplift from the breakdown of the nocturnal low-level jet before becoming visible in SEVIRI satellite imagery, (3) vertical profiles of the unique vertical structure of turbulent fluxes in the SABL, (4) in-situ observations of processes in SABL clouds showing dust acting as CCN and IN at -15 °C, (5) dual-aircraft observations of the SABL dynamics, thermodynamics and composition in the Saharan heat low region (SHL), (6) airborne observations of a dust storm associated with a cold-pool (haboob) issued from deep convection over the Atlas, (7) the first airborne chemical composition measurements of dust in the SHL region with differing composition, sources (determined using Lagrangian backward trajectory calculations) and absorption properties between 2011 and 2012, (8) coincident ozone and dust surface area measurements suggest coarser particles provide a route for ozone depletion, (9) discrepancies between airborne coarse mode size distributions and AERONET sunphotometer retrievals under

  12. Lessons learned from the introduction of cockpit automation in advanced technology aircraft

    SciTech Connect

    Nelson, W.R.; Byers, J.C.; Haney, L.N.; Ostrom, L.T.; Reece, W.J.

    1995-10-01

    The commercial aviation industry has many years of experience in the application of computer based human support systems, for example the flight management systems installed in today`s advanced technology (``glass cockpit``) aircraft. This experience can be very helpful in the design and implementation of similar systems for nuclear power plants. The National Aeronautics and Space Administration (NASA) sponsored a study at the Idaho National Engineering Laboratory (INEL) to investigate pilot errors that occur during interaction with automated systems in advanced technology aircraft. In particular, we investigated the causes and potential corrective measures for pilot errors that resulted in altitude deviation incidents (i.e. failure to capture or maintain the altitude assigned by air traffic control). To do this, we analyzed altitude deviation events that have been reported in the Aviation Safety Reporting System (ASRS), NASA`s data base of incidents self-reported by pilots and air traffic controllers. We developed models of the pilot tasks that are performed to capture and maintain altitude. Incidents from the ASRS data base were mapped onto the models, to highlight and categorize the potential causes of the errors. This paper reviews some of the problems that have resulted from the introduction of glass cockpit aircraft, the methodology used to analyze pilot errors, the lessons learned from the study of altitude deviation events, and the application of the results to the introduction of computer-based human support systems in nuclear power plants. In addition, a framework for using reliability engineering tools to incorporate lessons learned from operational experience into the design, construction, and operation of complex systems is briefly described.

  13. Turboprop Propulsion Mechanic 2-8. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    These military-developed curriculum materials for turboprop propulsion mechanics are targeted for use in grades 11-adult. Organized in five instructional blocks, the materials deal with the following topics: fundamentals of turboprop propulsion mechanics; engine and propeller systems operation; propeller maintenance; engine repair; and engine…

  14. Continued Development and Application of Circulation Control Pneumatic Technology to Advanced Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Englar, Robert J.

    1998-01-01

    Personnel of the Georgia Tech Research Institute (GTRI) Aerospace and Transportation Lab have completed a four-year grant program to develop and evaluate the pneumatic aerodynamic technology known as Circulation Control (CC) or Circulation Control Wing (CCW) for advanced transport aircraft. This pneumatic technology, which employs low-level blowing from tangential slots over round or near-round trailing edges of airfoils, greatly augments the circulation around a lifting or control surface and thus enhances the aerodynamic forces and moments generated by that surface. Two-dimensional force augmentations as high as 80 times the input blowing momentum coefficient have been recorded experimentally for these blown devices, thus providing returns of 8000% on the jet momentum expended. A further benefit is the absence of moving parts such as mechanical flaps, slats, spoilers, ailerons, elevators and rudders from these pneumatic surfaces, or the use of only very small, simple, blown aerodynamic surfaces on synergistic designs which integrate the lift, drag and control surfaces. The application of these devices to advanced aircraft can offer significant benefits in their performance, efficiency, simplicity, reliability, economic cost of operation, noise reduction, and safety of flight. To further develop and evaluate this potential, this research effort was conducted by GTRI under grant for the NASA Langley Research Center, Applied Aerodynamics Division, Subsonic Aerodynamics Branch, between June 14, 1993 and May 31, 1997.

  15. A simulation study of crew performance in operating an advanced transport aircraft in an automated terminal area environment

    NASA Technical Reports Server (NTRS)

    Houck, J. A.

    1983-01-01

    A simulation study assessing crew performance operating an advanced transport aircraft in an automated terminal area environment is described. The linking together of the Langley Advanced Transport Operating Systems Aft Flight Deck Simulator with the Terminal Area Air Traffic Model Simulation was required. The realism of an air traffic control (ATC) environment with audio controller instructions for the flight crews and the capability of inserting a live aircraft into the terminal area model to interact with computer generated aircraft was provided. Crew performance using the advanced displays and two separate control systems (automatic and manual) in flying area navigation routes in the automated ATC environment was assessed. Although the crews did not perform as well using the manual control system, their performances were within acceptable operational limits with little increase in workload. The crews favored using the manual control system and felt they were more alert and aware of their environment when using it.

  16. Design & fabrication of two seated aircraft with an advanced rotating leading edge wing

    NASA Astrophysics Data System (ADS)

    Al Ahmari, Saeed Abdullah Saeed

    The title of this thesis is "Design & Fabrication of two Seated Aircraft with an Advanced Rotating Leading Edge Wing", this gives almost a good description of the work has been done. In this research, the moving surface boundary-layer control (MSBC) concept was investigated and implemented. An experimental model was constructed and tested in wind tunnel to determine the aerodynamic characteristics using the leading edge moving surface of modified semi-symmetric airfoil NACA1214. The moving surface is provided by a high speed rotating cylinder, which replaces the leading edge of the airfoil. The angle of attack, the cylinder surfaces velocity ratio Uc/U, and the flap deflection angle effects on the lift and drag coefficients and the stall angle of attack were investigated. This new technology was applied to a 2-seat light-sport aircraft that is designed and built in the Aerospace Engineering Department at KFUPM. The project team is led by the aerospace department chairman Dr. Ahmed Z. AL-Garni and Dr. Wael G. Abdelrahman and includes graduate and under graduate student. The wing was modified to include a rotating cylinder along the leading edge of the flap portion. This produced very promising results such as the increase of the maximum lift coefficient at Uc/U=3 by 82% when flaps up and 111% when flaps down at 40° and stall was delayed by 8degrees in both cases. The laboratory results also showed that the effective range of the leading-edge rotating cylinder is at low angles of attack which reduce the need for higher angles of attack for STOL aircraft.

  17. Advancement of proprotor technology. Task 1: Design study summary. [aerodynamic concept of minimum size tilt proprotor research aircraft

    NASA Technical Reports Server (NTRS)

    1969-01-01

    A tilt-proprotor proof-of-concept aircraft design study has been conducted. The results are presented. The ojective of the contract is to advance the state of proprotor technology through design studies and full-scale wind-tunnel tests. The specific objective is to conduct preliminary design studies to define a minimum-size tilt-proprotor research aircraft that can perform proof-of-concept flight research. The aircraft that results from these studies is a twin-engine, high-wing aircraft with 25-foot, three-bladed tilt proprotors mounted on pylons at the wingtips. Each pylon houses a Pratt and Whitney PT6C-40 engine with a takeoff rating of 1150 horsepower. Empty weight is estimated at 6876 pounds. The normal gross weight is 9500 pounds, and the maximum gross weight is 12,400 pounds.

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

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Comey, D. H.

    1977-01-01

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

  20. The advanced microwave precipitation radiometer: A new aircraft radiometer for passive precipitation remote sensing

    NASA Technical Reports Server (NTRS)

    Hood, Robbie E.; Spencer, Roy W.; James, Mark W.

    1991-01-01

    Past studies of passive microwave measurements of precipitating systems have yielded broad empirical relationships between hydrometeors and microwave transmission. In general, these relationships fall into two categories of passive microwave precipitation retrievals rely upon the observed effect of liquid precipitation to increase the brightness temperature of a radiometrically cold background such as an ocean surface. A scattering-based method is based upon the effect that frozen hydrometeors tend to decrease the brightness temperature of a radiometrically warm background such as land. One step toward developing quantitative brightness temperature-rain rate relationships is the recent construction of a new aircraft instrument sponsored by National Aeronautics and Space Administration/Marshall Space Flight Center (NASA/MSFC). This instrument is the Advanced Microwave Precipitation Radiometer (AMPR) designed and built by Georgia Tech Research Institute to fly aboard high altitude research aircraft such as the NASA ER-2. The AMPR and its accompanying data acquisition system are mounted in the Q-bay compartment of the NASA ER-2.

  1. Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations

    NASA Astrophysics Data System (ADS)

    Ryder, C. L.; McQuaid, J. B.; Flamant, C.; Rosenberg, P. D.; Washington, R.; Brindley, H. E.; Highwood, E. J.; Marsham, J. H.; Parker, D. J.; Todd, M. C.; Banks, J. R.; Brooke, J. K.; Engelstaedter, S.; Estelles, V.; Formenti, P.; Garcia-Carreras, L.; Kocha, C.; Marenco, F.; Sodemann, H.; Allen, C. J. T.; Bourdon, A.; Bart, M.; Cavazos-Guerra, C.; Chevaillier, S.; Crosier, J.; Darbyshire, E.; Dean, A. R.; Dorsey, J. R.; Kent, J.; O'Sullivan, D.; Schepanski, K.; Szpek, K.; Trembath, J.; Woolley, A.

    2015-07-01

    The Fennec climate programme aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes they have provided. Aircraft instrumentation aboard the UK FAAM BAe146 and French SAFIRE (Service des Avions Français Instrumentés pour la Recherche en Environnement) Falcon 20 is described, with specific focus on instrumentation specially developed for and relevant to Saharan meteorology and dust. Flight locations, aims and associated meteorology are described. Examples and applications of aircraft measurements from the Fennec flights are presented, highlighting new scientific results delivered using a synergy of different instruments and aircraft. These include (1) the first airborne measurement of dust particles sizes of up to 300 microns and associated dust fluxes in the Saharan atmospheric boundary layer (SABL), (2) dust uplift from the breakdown of the nocturnal low-level jet before becoming visible in SEVIRI (Spinning Enhanced Visible Infra-Red Imager) satellite imagery, (3) vertical profiles of the unique vertical structure of turbulent fluxes in the SABL, (4) in situ observations of processes in SABL clouds showing dust acting as cloud condensation nuclei (CCN) and ice nuclei (IN) at -15 °C, (5) dual-aircraft observations of the SABL dynamics, thermodynamics and composition in the Saharan heat low region (SHL), (6) airborne observations of a dust storm associated with a cold pool (haboob) issued from deep convection over the Atlas Mountains, (7) the first airborne chemical composition measurements of dust in the SHL region with differing composition, sources (determined using Lagrangian backward trajectory calculations) and absorption properties between 2011 and 2012, (8) coincident ozone and dust surface area

  2. Development and testing of improved polyimide actuator rod seals at higher temperatures for use in advanced aircraft hydraulic systems

    NASA Technical Reports Server (NTRS)

    Robinson, E. D.; Waterman, A. W.; Nelson, W. G.

    1972-01-01

    Polyimide second stage rod seals were evaluated to determine their suitability for application in advanced aircraft systems. The configurations of the seals are described. The conditions of the life cycle tests are provided. It was determined that external rod seal leakage was within prescribed limits and that the seals showed no signs of structural degradation.

  3. 75 FR 36034 - Advance Notice of Proposed Rulemaking on Lead Emissions From Piston-Engine Aircraft Using Leaded...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-24

    ... provide comment on the ANPR. DATES: The comment period for the ANPR published April 28, 2010 (75 FR 22440... AGENCY 40 CFR Part 87 RIN 2060-AP79 Advance Notice of Proposed Rulemaking on Lead Emissions From Piston... Rulemaking on Lead Emissions From Piston-Engine Aircraft Using Leaded Aviation Gasoline (hereinafter...

  4. Effect of Advanced Location Methods on Search and Rescue Duration for General Aviation Aircraft Accidents in the Contiguous United States

    ERIC Educational Resources Information Center

    Wallace, Ryan J.

    2013-01-01

    The purpose of this study was to determine the impact of advanced search and rescue devices and techniques on search duration for general aviation aircraft crashes. The study assessed three categories of emergency locator transmitters, including 121.5 MHz, 406 MHz, and GPS-Assisted 406 MHz devices. The impact of the COSPAS-SARSAT organization…

  5. Propulsion-airframe integration for commercial and military aircraft

    NASA Technical Reports Server (NTRS)

    Henderson, William P.

    1988-01-01

    A significant level of research is ongoing at NASA's Langley Research Center on integrating the propulsion system with the aircraft. This program has included nacelle/pylon/wing integration for turbofan transports, propeller/nacelle/wing integration for turboprop transports, and nozzle/afterbody/empennage integration for high performance aircraft. The studies included in this paper focus more specifically on pylon shaping and nacelle location studies for turbofan transports, nacelle and wing contouring and propeller location effects for turboprop transports, and nozzle shaping and empennage effects for high performance aircraft. The studies were primarily conducted in NASA Langley's 16-Foot Transonic Tunnel at Mach numbers up to 1.20. Some higher Mach number data obtained at NASA's Lewis Research Center is also included.

  6. Preliminary design of a family of three close air support aircraft

    NASA Technical Reports Server (NTRS)

    Cox, Brian; Darrah, Paul; Lussier, Wayne; Mills, Nikos

    1989-01-01

    A family of three Close Air Support aircraft is presented. These aircraft are designed with commonality as the main design objective to reduce the life cycle cost. The aircraft are low wing, twin-boom, pusher turbo-prop configurations. The amount of information displayed to the pilot was reduced to a minimum to greatly simplify the cockpit. The aircraft met the mission specifications and the performance and cost characteristics compared well with other CAS aircraft. The concept of a family of CAS aircraft seems viable after preliminary design.

  7. Development of an advanced pitch active control system for a wide body jet aircraft

    NASA Technical Reports Server (NTRS)

    Guinn, Wiley A.; Rising, Jerry J.; Davis, Walt J.

    1984-01-01

    An advanced PACS control law was developed for a commercial wide-body transport (Lockheed L-1011) by using modern control theory. Validity of the control law was demonstrated by piloted flight simulation tests on the NASA Langley visual motion simulator. The PACS design objective was to develop a PACS that would provide good flying qualities to negative 10 percent static stability margins that were equivalent to those of the baseline aircraft at a 15 percent static stability margin which is normal for the L-1011. Also, the PACS was to compensate for high-Mach/high-g instabilities that degrade flying qualities during upset recoveries and maneuvers. The piloted flight simulation tests showed that the PACS met the design objectives. The simulation demonstrated good flying qualities to negative 20 percent static stability margins for hold, cruise and high-speed flight conditions. Analysis and wind tunnel tests performed on other Lockheed programs indicate that the PACS could be used on an advanced transport configuration to provide a 4 percent fuel savings which results from reduced trim drag by flying at negative static stability margins.

  8. Flight service evaluation of an advanced composite empennage component on commercial transport aircraft

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The development and flight evaluation of an advanced composite empennage component is presented. The recommended concept for the covers is graphite-epoxy hats bonded to a graphite-epoxy skin. The hat flare-out has been eliminated, instead the hat is continuous into the joint. The recommended concept for the spars is graphite-epoxy caps and a hybrid of Kevlar-49 and graphite-epoxy in the spar web. The spar cap, spar web stiffeners for attaching the ribs, and intermediate stiffeners are planned to be fabricated as a unit. Access hole in the web will be reinforced with a donut type, zero degree graphite-epoxy wound reinforcement. The miniwich design concept in the upper three ribs originally proposed is changed to a graphite-epoxy stiffened solid laminate design concept. The recommended configuration for the lower seven ribs remains as graphite-epoxy caps with aluminum cruciform diagonals. The indicated weight saving for the current advanced composite vertical fin configuration is 20.2% including a 24 lb growth allowance. The project production cost saving is approximately 1% based on a cumulative average of 250 aircraft and including only material, production labor, and quality assurance costs.

  9. Study of the application of advanced technologies to long-range transport aircraft. Volume 2: Research and development requirements

    NASA Technical Reports Server (NTRS)

    Lange, R. H.; Sturgeon, R. F.; Adams, W. E.; Bradley, E. S.; Cahill, J. F.; Eudaily, R. R.; Hancock, J. P.; Moore, J. W.

    1972-01-01

    Investigations were conducted to evaluate the relative benefits attainable through the exploitation of advanced technologies and to identify future research and development efforts required to permit the application of selected technologies to transport aircraft entering commercial operation in 1985. Results show that technology advances, particularly in the areas of composite materials, supercritical aerodynamics, and active control systems, will permit the development of long-range, high-payload commercial transports operating at high-subsonic speeds with direct operating costs lower than those of current aircraft. These advanced transports also achieve lower noise levels and lower engine pollutant emissions than current transports. Research and development efforts, including analytical investigations, laboratory test programs, and flight test programs, are required in essentially all technology areas to achieve the potential technology benefits.

  10. Design of short haul aircraft for fuel conservation

    NASA Technical Reports Server (NTRS)

    Bowden, M. K.; Sweet, H. S.; Waters, M. H.

    1975-01-01

    Current jet fuel prices of twice the 1972 level have significantly changed the characteristics of airplane design for best economy. The results of a contract with the NASA Ames Advanced Concepts and Missions Division confirmed the economic desirability of lower design cruise speeds and higher aspect-ratio wings compared to designs developed in the by-gone era of low fuel price. Evaluation of potential fuel conservation for short-haul aircraft showed that an interaction of airfoil technology and desirable engine characteristics is important: the supercritical airfoil permits higher aspect ratio wings with lower sweep; these, in turn, lower the cruise thrust requirements so that engines with higher bypass ratios are better matched in terms of lapse rate; lower cruise speeds (which are also better for fuel and operating cost economy) push the desired bypass ratio up further. Thus, if fuel prices remain high, or rise further, striking reductions in community noise level can be achieved as a fallout in development of a 1980s airplane and engine. Analyses are presented of developmental trends in the design of short-haul aircraft with lower cruise speeds and higher aspect-ratio wings, and the effects on fuel consumption of design field length, powered lift concepts, and turboprop as well as turbofan propulsion are discussed.

  11. Device-Task Fidelity and Transfer of Training: Aircraft Cockpit Procedures Training.

    ERIC Educational Resources Information Center

    Prophet, Wallace W.; Boyd, H. Alton

    An evaluation was made of the training effectiveness of two cockpit procedures training devices, differing greatly in physical fidelity and cost, for use on the ground for a twin-engine, turboprop, fixed-wing aircraft. One group of students received training in cockpit procedures in a relatively expensive, sophisticated, computerized trainer,…

  12. Fatigue life analysis of a turboprop reduction gearbox

    NASA Technical Reports Server (NTRS)

    Lewicki, D. G.; Black, J. D.; Savage, M.; Coy, J. J.

    1985-01-01

    A fatigue life analysis of the Allison T56/501 turboprop reduction gearbox was developed. The life and reliability of the gearbox was based on the lives and reliabilities of the main power train bearings and gears. The bearing and gear lives were determined using the Lundberg-Palmgren theory and a mission profile. The five planet bearing set had the shortest calculated life among the various gearbox components, which agreed with field experience where the planet bearing had the greatest incidences of failure. The analytical predictions of relative lives among the various bearings were in reasonable agreement with field experience. The predicted gearbox life was in excellent agreement with field data when the material life adjustment factors alone were used. The gearbox had a lower predicted life in comparison with field data when no life adjustment factors were used or when lubrication life adjustment factors were used either alone or in combination with the material factors.

  13. Fatigue life analysis of a turboprop reduction gearbox

    NASA Technical Reports Server (NTRS)

    Lewicki, D. G.; Coy, J. J.; Black, J. D.; Savage, M.

    1986-01-01

    A fatigue life analysis of the Allison T56/501 turboprop reduction gearbox was developed. The life and reliability of the gearbox was based on the lives and reliabilities of the main power train bearings and gears. The bearing and gear lives were determined using the Lundberg-Palmgren theory and a mission profile. The five planet bearing set had the shortest calculated life among the various gearbox components, which agreed with field experience where the planet bearing had the greatest incidences of failure. The analytical predictions of relative lives among the various bearings were in reasonable agreement with field experience. The predicted gearbox life was in excellent agreement with field data when the material life adjustment factors alone were used. The gearbox had a lower predicted life in comparison with field data when no life adjustment factors were used or when lubrication life adjustment factors were used either alone or in combination with the material factors.

  14. Noise abatement technology options for conventional turboprop airplanes. Final report

    SciTech Connect

    Galloway, W.J.; Wilby, J.F.

    1981-06-01

    The practical application of noise control technology to new and derivative conventional turboprop airplanes likely to come into service in the 1980's has been analyzed with a view to determining noise control cost/benefits. The analysis identifies feasible noise control methods, applies them to four study airplanes, and presents the noise reductions in terms of the equivalent perceived noise level at takeoff, sideline and approach locations, and the effect on the area within selected EPNL contours. Noise reductions of up to 8.3 dB for takeoff and 10.7 dB for approach are calculated for the study airplanes but, for most cases, the changes are less than 5 dB. Weight and cost increases associated with the noise control treatments are determined under the assumption there they are no changes to airplane performance or fuel consumption.

  15. Study of flutter related computational procedures for minimum weight structural sizing of advanced aircraft

    NASA Technical Reports Server (NTRS)

    Oconnell, R. F.; Hassig, H. J.; Radovcich, N. A.

    1976-01-01

    Results of a study of the development of flutter modules applicable to automated structural design of advanced aircraft configurations, such as a supersonic transport, are presented. Automated structural design is restricted to automated sizing of the elements of a given structural model. It includes a flutter optimization procedure; i.e., a procedure for arriving at a structure with minimum mass for satisfying flutter constraints. Methods of solving the flutter equation and computing the generalized aerodynamic force coefficients in the repetitive analysis environment of a flutter optimization procedure are studied, and recommended approaches are presented. Five approaches to flutter optimization are explained in detail and compared. An approach to flutter optimization incorporating some of the methods discussed is presented. Problems related to flutter optimization in a realistic design environment are discussed and an integrated approach to the entire flutter task is presented. Recommendations for further investigations are made. Results of numerical evaluations, applying the five methods of flutter optimization to the same design task, are presented.

  16. A Study of the Utilization of Advanced Composites in Fuselage Structures of Commercial Aircraft

    NASA Technical Reports Server (NTRS)

    Watts, D. J.; Sumida, P. T.; Bunin, B. L.; Janicki, G. S.; Walker, J. V.; Fox, B. R.

    1985-01-01

    A study was conducted to define the technology and data needed to support the introduction of advanced composites in the future production of fuselage structure in large transport aircraft. Fuselage structures of six candidate airplanes were evaluated for the baseline component. The MD-100 was selected on the basis of its representation of 1990s fuselage structure, an available data base, its impact on the schedule and cost of the development program, and its availability and suitability for flight service evaluation. Acceptance criteria were defined, technology issues were identified, and a composite fuselage technology development plan, including full-scale tests, was identified. The plan was based on composite materials to be available in the mid to late 1980s. Program resources required to develop composite fuselage technology are estimated at a rough order of magnitude to be 877 man-years exclusive of the bird strike and impact dynamic test components. A conceptual composite fuselage was designed, retaining the basic MD-100 structural arrangement for doors, windows, wing, wheel wells, cockpit enclosure, major bulkheads, etc., resulting in a 32 percent weight savings.

  17. Advanced Low NO Sub X Combustors for Supersonic High-Altitude Aircraft Gas Turbines

    NASA Technical Reports Server (NTRS)

    Roberts, P. B.; White, D. J.; Shekleton, J. R.

    1975-01-01

    A test rig program was conducted with the objective of evaluating and minimizing the exhaust emissions, in particular NO sub x, of three advanced aircraft combustor concepts at a simulated, high altitude cruise condition. The three combustor designs, all members of the lean reaction, premixed family, are the Jet Induced Circulation (JIC) combustor, the Vortex Air Blast (VAB) combustor, and a catalytic combustor. They were rig tested in the form of reverse flow can combustors in the 0.127 m. (5.0 in.) size range. Various configuration modifications were applied to each of the initial JIC and VAB combustor model designs in an effort to reduce the emissions levels. The VAB combustor demonstrated a NO sub x level of 1.1 gm NO2/kg fuel with essentially 100% combustion efficiency at the simulated cruise combustor condition of 50.7 N/sq cm (5 atm), 833 K (1500 R) inlet pressure and temperature respectively and 1778 K (3200 R) outlet temperature on Jet-A1 fuel. Early tests on the catalytic combustor were unsuccessful due to a catalyst deposition problem and were discontinued in favor of the JIC and VAB tests. In addition emissions data were obtained on the JIC and VAB combustors at low combustor inlet pressure and temperatures that indicate the potential performance at engine off-design conditions.

  18. Advanced low NO/x/ combustors for supersonic high-altitude aircraft gas turbines

    NASA Technical Reports Server (NTRS)

    Roberts, P. B.; Shekleton, J. R.; White, D. J.; Butze, H. F.

    1976-01-01

    A test rig program was conducted with the objective of evaluating and minimizing the exhaust emissions, in particular NO(x), of two advanced aircraft combustor concepts at a simulated, high-altitude cruise condition. The two combustor designs, both members of the lean-reaction, pre-mixed family, are known as the Jet Induced Circulation (JIC) combustor and the Vortex Air Blast (VAB) combustor and were rig tested in the form of reverse flow can combustors in the 0.127-m size range. Various configuration modifications were applied to each of the initial JIC and VAB combustor model designs in an effort to reduce the emissions levels. The VAB combustor demonstrated a NO(x) level of 1.1 gm NO2/kg fuel with essentially 100 percent combustion efficiency at the simulated cruise combustor condition of 507 kPa, 833 K inlet pressure and temperature, respectively and 1778 K outlet temperature on Jet-A1 fuel. In addition, emissions data were obtained at low combustor inlet pressure and temperatures that indicate the potential performance at engine off-design conditions.

  19. Advanced manufacturing development of a composite empennage component for L-1011 aircraft

    NASA Technical Reports Server (NTRS)

    Alva, T.; Henkel, J.; Johnson, R.; Carll, B.; Jackson, A.; Mosesian, B.; Brozovic, R.; Obrien, R.; Eudaily, R.

    1982-01-01

    This is the final report of technical work conducted during the fourth phase of a multiphase program having the objective of the design, development and flight evaluation of an advanced composite empennage component manufactured in a production environment at a cost competitive with those of its metal counterpart, and at a weight savings of at least 20 percent. The empennage component selected for this program is the vertical fin box of the L-1011 aircraft. The box structure extends from the fuselage production joint to the tip rib and includes front and rear spars. During Phase 4 of the program, production quality tooling was designed and manufactured to produce three sets of covers, ribs, spars, miscellaneous parts, and subassemblies to assemble three complete ACVF units. Recurring and nonrecurring cost data were compiled and documented in the updated producibility/design to cost plan. Nondestruct inspections, quality control tests, and quality acceptance tests were performed in accordance with the quality assurance plan and the structural integrity control plan. Records were maintained to provide traceability of material and parts throughout the manufacturing development phase. It was also determined that additional tooling would not be required to support the current and projected L-1011 production rate.

  20. How Past Loss of Control Accidents May Inform Safety Cases for Advanced Control Systems on Commercial Aircraft

    NASA Technical Reports Server (NTRS)

    Holloway, C. M.; Johnson, C. W.

    2008-01-01

    This paper describes five loss of control accidents involving commercial aircraft, and derives from those accidents three principles to consider when developing a potential safety case for an advanced flight control system for commercial aircraft. One, among the foundational evidence needed to support a safety case is the availability to the control system of accurate and timely information about the status and health of relevant systems and components. Two, an essential argument to be sustained in the safety case is that pilots are provided with adequate information about the control system to enable them to understand the capabilities that it provides. Three, another essential argument is that the advanced control system will not perform less safely than a good pilot.

  1. The impact of transition training on adapting to Technically Advanced Aircraft at regional airlines: Perceptions of pilots and instructor pilots

    NASA Astrophysics Data System (ADS)

    di Renzo, John Carl, Jr.

    Scope and method of study. The purpose of this study was to test a hypothesis about pilot and instructor pilot perceptions of how effectively pilots learn and use new technology, found in Technically Advanced Aircraft (TAA), given initial type of instrumentation training. New aviation technologies such as Glass Cockpits in technically advanced aircraft are complex and can be difficult to learn and use. The research questions focused on the type of initial instrumentation training to determine the differences among pilots trained using various types of instrumentation ranging from aircraft equipped with traditional analog instrumentation to aircraft equipped with glass cockpits. A convenience sample of Pilots in Training (PT) and Instructor Pilots (IP) was selected from a regional airline. The research design used a mixed methodology. Pilots in training completed a thirty-two question quantitative questionnaire and instructor pilots completed a five question qualitative questionnaire. Findings and conclusions. This investigation failed to disprove the null hypothesis. The type of instrumentation training has no significant effect on newly trained regional airline pilot perceived ability to adapt to advanced technology cockpits. Therefore, no evidence exists from this investigation to support the early introduction and training of TAA. While the results of this investigation were surprising, they are nonetheless, instructive. Even though it would seem that there would be a relationship between exposure to and use of technically advanced instrumentation, apparently there was no perceived relationship for this group of airline transport pilots. However, a point of interest is that these pilots were almost evenly divided in their opinion of whether or not their previous training had prepared them for transition to TAA. The majority also believed that the type of initial instrumentation training received does make a difference when transitioning to TAA. Pilots believed

  2. Recent experience with multidisciplinary analysis and optimization in advanced aircraft design

    NASA Technical Reports Server (NTRS)

    Dollyhigh, Samuel M.; Sobieszczanski-Sobieski, Jaroslaw

    1990-01-01

    The task of modern aircraft design has always been complicated due to the number of intertwined technical factors from the various engineering disciplines. Furthermore, this complexity has been rapidly increasing by the development of such technologies as aeroelasticity tailored materials and structures, active control systems, integrated propulsion/airframe controls, thrust vectoring, and so on. Successful designs that achieve maximum advantage from these new technologies require a thorough understanding of the physical phenomena and the interactions among these phenomena. A study commissioned by the Aeronautical Sciences and Evaluation Board of the National Research Council has gone so far as to identify technology integration as a new discipline from which many future aeronautical advancements will arise. Regardless of whether one considers integration as a new discipline or not, it is clear to all engineers involved in aircraft design and analysis that better methods are required. In the past, designers conducted parametric studies in which a relatively small number of principal characteristics were varied to determine the effect on design requirements which were themselves often diverse and contradictory. Once a design was chosen, it then passed through the various engineers' disciplines whose principal task was to make the chosen design workable. Working in a limited design space, the discipline expert sometimes improved the concept, but more often than not, the result was in the form of a penalty to make the original concept workable. If an insurmountable problem was encountered, the process began over. Most design systems that attempt to account for disciplinary interactions have large empirical elements and reliance on past experience is a poor guide in obtaining maximum utilizations of new technologies. Further compounding the difficulty of design is that as the aeronautical sciences have matured, the discipline specialist's area of research has generally

  3. Advanced microstrip antenna developments. Volume 2: Microstrip GPS antennas for general aviation aircraft

    NASA Astrophysics Data System (ADS)

    Sanford, G. G.; Gross, B. D.

    1982-03-01

    This report describes the application of microstrip antenna technology to the design of general aviation (G/A) aircraft antennas for use with the Global Positioning System (GPS). For most G/A aircraft, only single frequency operation will be required. However, air-carrier and some large corporate aircraft may make use of dual-frequency operation. For this reason, some dual-frequency designs have been investigated. The main effort was given to the design of antennas with broad beamwidths which could be switched or steered to compensate for aircraft maneuvers, with the goal of maintaining near-hemispherical carriage in flight. A hybrid microstrip crossed-slot and sleeve-dipole element used with a suitable combining network gives a suitable, controllable broad-beam pattern. This element and its performance are described. In addition, radiation patterns are presented using scale-model aircraft and simple crossed-slot antennas.

  4. Characterization of particulate matter and gaseous emissions of a C-130H aircraft.

    PubMed

    Corporan, Edwin; Quick, Adam; DeWitt, Matthew J

    2008-04-01

    The gaseous and nonvolatile particulate matter (PM) emissions of two T56-A-15 turboprop engines of a C-130H aircraft stationed at the 123rd Airlift Wing in the Kentucky Air National Guard were characterized. The emissions campaign supports the Strategic Environmental Research and Development Program (SERDP) project WP-1401 to determine emissions factors from military aircraft. The purpose of the project is to develop a comprehensive emissions measurement program using both conventional and advanced techniques to determine emissions factors of pollutants, and to investigate the spatial and temporal evolutions of the exhaust plumes from fixed and rotating wing military aircraft. Standard practices for the measurement of gaseous emissions from aircraft have been well established; however, there is no certified methodology for the measurement of aircraft PM emissions. In this study, several conventional instruments were used to physically characterize and quantify the PM emissions from the two turboprop engines. Emissions samples were extracted from the engine exit plane and transported to the analytical instrumentation via heated lines. Multiple sampling probes were used to assess the spatial variation and obtain a representative average of the engine emissions. Particle concentrations, size distributions, and mass emissions were measured using commercially available aerosol instruments. Engine smoke numbers were determined using established Society of Automotive Engineers (SAE) practices, and gaseous species were quantified via a Fourier-transform infrared-based gas analyzer. The engines were tested at five power settings, from idle to take-off power, to cover a wide range of operating conditions. Average corrected particle numbers (PNs) of (6.4-14.3) x 10(7) particles per cm3 and PN emission indices (EI) from 3.5 x 10(15) to 10.0 x 10(15) particles per kg-fuel were observed. The highest PN EI were observed for the idle power conditions. The mean particle diameter

  5. Military Aircraft Emissions Research - Case of Hercules Cargo Plane (C-130H) Emissions

    SciTech Connect

    Cheng, Mengdawn; Corporan, E.; DeWitt, M.; Harris, B.; Hashmonay, R.; Holdren, M.; Kaganan, R.; Spicer, C.

    2007-01-01

    Tactical airlifter like C-130H has been in use for more than 50 years, and is expected to serve for many years to come. However, the emission characteristics data of the aircraft are scarce. To increase our understanding of turboprop engine emissions, emissions from a military C-130H cargo aircraft were characterized in field conditions in the fall of 2005. Particulate and gaseous pollutants were measured by conventional and advanced instrumentation platforms that were built with in-situ extractive or remote optical sensing technologies. The measurements performed at the C-130H engine exhaust exit showed increased levels of emissions as the engine power setting increased. In contrast, there was no such a relationship found for the C-130H emitted particulate matter (as a function of engine power setting) measured at about 15-m downstream of the engine exhaust plane. The emitted gaseous species measured at both locations were, however, proportional to the engine power setting and comparable (at both locations) when corrected for ambient dilution indicating the lack of particulate emission-power setting relationship at the far field is unique. The result clearly indicates that the aircraft emission factor or index for particulate matter cannot be experimentally determined at a downstream location away from the exhaust exit and has to be determined right at the engine exhaust plane. Emission indices that are needed for air quality modeling will be presented.

  6. 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.

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

    NASA Technical Reports Server (NTRS)

    Gilinsky, Mikhail; Morgan, Morris H.; Povitsky, Alex; Schkolnikov, Natalia; Njoroge, Norman; Coston, Calvin; Blankson, Isaiah M.

    2001-01-01

    The Fluid Mechanics and Acoustics Laboratory at Hampton University (HU/FM&AL) jointly with the NASA Glenn Research Center has conducted four connected subprojects under the reporting project. Basically, the HU/FM&AL Team has been involved in joint research with the purpose of theoretical explanation of experimental facts and creation of accurate numerical simulation techniques and prediction theory for solution of current problems in propulsion systems of interest to the NAVY and NASA agencies. This work is also supported by joint research between the NASA GRC and the Institute of Mechanics at Moscow State University (IM/MSU) in Russia under a CRDF grant. The research is focused on a wide regime of problems in the propulsion field as well as in experimental testing and theoretical and numerical simulation analyses for advanced aircraft and rocket engines. The FM&AL Team uses analytical methods, numerical simulations and possible experimental tests at the Hampton University campus. The fundamental idea uniting these subprojects is to use nontraditional 3D corrugated and composite nozzle and inlet designs and additional methods for exhaust jet noise reduction without essential thrust loss and even with thrust augmentation. These subprojects are: (1) Aeroperformance and acoustics of Bluebell-shaped and Telescope-shaped designs; (2) An analysis of sharp-edged nozzle exit designs for effective fuel injection into the flow stream in air-breathing engines: triangular-round, diamond-round and other nozzles; (3) Measurement technique improvement for the HU Low Speed Wind Tunnel; a new course in the field of aerodynamics, teaching and training of HU students; experimental tests of Mobius-shaped screws: research and training; (4) Supersonic inlet shape optimization. The main outcomes during this reporting period are: (l) Publications: The AIAA Paper #00-3170 was presented at the 36th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 17-19 June, 2000, Huntsville, AL. The AIAA

  8. NASA technical advances in aircraft occupant safety. [clear air turbulence detectors, fire resistant materials, and crashworthiness

    NASA Technical Reports Server (NTRS)

    Enders, J. H.

    1978-01-01

    NASA's aviation safety technology program examines specific safety problems associated with atmospheric hazards, crash-fire survival, control of aircraft on runways, human factors, terminal area operations hazards, and accident factors simulation. While aircraft occupants are ultimately affected by any of these hazards, their well-being is immediately impacted by three specific events: unexpected turbulence encounters, fire and its effects, and crash impact. NASA research in the application of laser technology to the problem of clear air turbulence detection, the development of fire resistant materials for aircraft construction, and to the improvement of seats and restraint systems to reduce crash injuries are reviewed.

  9. Advanced Methods for Acoustic and Thrust Benefits for Aircraft Engine Nozzle

    NASA Technical Reports Server (NTRS)

    Gilinsky, Mikhail M.

    1998-01-01

    The purpose of this paper is to address the problems of Aircraft Engine Technology, Airframe Technology, and Rotorcraft Technology. In addition, several applied problems for domestic industry are also studied using knowledge and experience from Aerospace Sciences. The reduction of aircraft noise is a significant driver in the success of the NASA AST and HSR programs as they attempt to meet stringent international environment regulations on noise for commercial aircraft. In accordance with the project fulfillment under this NASA grant the (Fluid Mechanics and Acoustics Laboratory) FM&AL investigates novel and promising concepts for reduction of noise and improvement of propulsion efficiency in jet exhaust nozzles and fans.

  10. Advanced air transport concepts. [review of design methods for very large aircraft

    NASA Technical Reports Server (NTRS)

    Molloy, J. K.

    1979-01-01

    The concepts of laminar flow control, very large all-wing aircraft, an aerial relay transportation system and alternative fuels, which would enable large improvements in fuel conservation in air transportation in the 1990's are discussed. Laminar boundary layer control through suction would greatly reduce skin friction and has been reported to reduce fuel consumption by up to 29%. Distributed load aircraft, in which all fuel and payload are carried in the wing and the fuselage is absent, permit the use of lighter construction materials and the elimination of fuselage and tail drag. Spanloader aircraft with laminar flow control could be used in an aerial relay transportation system which would employ a network of continuously flying liners supplied with fuel, cargo and crews by smaller feeder aircraft. Liquid hydrogen and methane fuels derived from coal are shown to be more weight efficient and less costly than coal-derived synthetic jet fuels.

  11. The development of advanced automatic flare and decrab for powered lift short haul aircraft using a microwave landing system

    NASA Technical Reports Server (NTRS)

    Gevaert, G.; Feinreich, B.

    1977-01-01

    Advanced automatic flare and decrab control laws were developed for future powered lift STOL aircraft using the NASA-C-8A augmentor wing vehicle as the aircraft model. The longitudinal control laws utilize the throttle for flight path control and use the direct lift augmentor flap chokes for flight path augmentation. The elevator is used to control airspeed during the approach phase and to enhance path control during the flare. The forward slip maneuver was selected over the flat decrab technique for runway alignment because it can effectively handle the large crab angles obtained at STOL approach speeds. Performance evaluation of selected system configurations were obtained over the total landing environment. Limitations were defined and critical failure modes assessed. Pilot display concepts are discussed.

  12. 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.

  13. Advances in Small Remotely Piloted Aircraft Communications and Remote Sensing in Maritime Environments including the Arctic

    NASA Astrophysics Data System (ADS)

    McGillivary, P. A.; Borges de Sousa, J.; Wackowski, S.; Walker, G.

    2011-12-01

    Small remotely piloted aircraft have recently been used for maritime remote sensing, including launch and retrieval operations from land, ships and sea ice. Such aircraft can also function to collect and communicate data from other ocean observing system platforms including moorings, tagged animals, drifters, autonomous surface vessels (ASVs), and autonomous underwater vessels (AUVs). The use of small remotely piloted aircraft (or UASs, unmanned aerial systems) with a combination of these capabilities will be required to monitor the vast areas of the open ocean, as well as in harsh high-latitude ecosystems. Indeed, these aircraft are a key component of planned high latitude maritime domain awareness environmental data collection capabilities, including use of visible, IR and hyperspectral sensors, as well as lidar, meteorological sensors, and interferometric synthetic aperture radars (ISARs). We here first describe at-sea demonstrations of improved reliability and bandwidth of communications from ocean sensors on autonomous underwater vehicles to autonomous surface vessels, and then via remotely piloted aircraft to shore, ships and manned aircraft using Delay and Disruption Tolerant (DTN) communication protocols. DTN enables data exchange in communications-challenged environments, such as remote regions of the ocean including high latitudes where low satellite angles and auroral disturbances can be problematic. DTN provides a network architecture and application interface structured around optionally-reliable asynchronous message forwarding, with limited expectations of end-to-end connectivity and node resources. This communications method enables aircraft and surface vessels to function as data mules to move data between physically disparate nodes. We provide examples of the uses of this communication protocol for environmental data collection and data distribution with a variety of different remotely piloted aircraft in a coastal ocean environment. Next, we

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

    NASA Technical Reports Server (NTRS)

    Morgan, Morris H.; Gilinsky, Mikhail M.

    2001-01-01

    Three connected sub-projects were conducted under reported project. Partially, these sub-projects are directed to solving the problems conducted by the HU/FM&AL under two other NASA grants. The fundamental idea uniting these projects is to use untraditional 3D corrugated nozzle designs and additional methods for exhaust jet noise reduction without essential thrust lost and even with thrust augmentation. Such additional approaches are: (1) to add some solid, fluid, or gas mass at discrete locations to the main supersonic gas stream to minimize the negative influence of strong shock waves forming in propulsion systems; this mass addition may be accompanied by heat addition to the main stream as a result of the fuel combustion or by cooling of this stream as a result of the liquid mass evaporation and boiling; (2) to use porous or permeable nozzles and additional shells at the nozzle exit for preliminary cooling of exhaust hot jet and pressure compensation for non-design conditions (so-called continuous ejector with small mass flow rate; and (3) to propose and analyze new effective methods fuel injection into flow stream in air-breathing engines. Note that all these problems were formulated based on detailed descriptions of the main experimental facts observed at NASA Glenn Research Center. Basically, the HU/FM&AL Team has been involved in joint research with the purpose of finding theoretical explanations for experimental facts and the creation of the accurate numerical simulation technique and prediction theory for solutions for current problems in propulsion systems solved by NASA and Navy agencies. The research is focused on a wide regime of problems in the propulsion field as well as in experimental testing and theoretical and numerical simulation analysis for advanced aircraft and rocket engines. The F&AL Team uses analytical methods, numerical simulations, and possible experimental tests at the Hampton University campus. We will present some management activity

  15. Aircraft gas-turbine engines: Noise reduction and vibration control. (Latest citations from Information Services in Mechanical Engineering data base). Published Search

    SciTech Connect

    Not Available

    1992-06-01

    The bibliography contains citations concerning the design and analysis of aircraft gas turbine engines with respect to noise and vibration control. Included are studies regarding the measurement and reduction of noise at its source, within the aircraft, and on the ground. Inlet, nozzle and core aerodynamic studies are cited. Propfan, turbofan, turboprop engines, and applications in short take-off and landing (STOL) aircraft are included. (Contains a minimum of 202 citations and includes a subject term index and title list.)

  16. A study to define the research and technology requirements for advanced turbo/propfan transport aircraft

    NASA Technical Reports Server (NTRS)

    Goldsmith, I. M.

    1981-01-01

    The feasibility of the propfan relative to the turbofan is summarized, using the Douglas DC-9 Super 80 (DS-8000) as the actual operational base aircraft. The 155 passenger economy class aircraft (31,775 lb 14,413 kg payload), cruise Mach at 0.80 at 31,000 ft (8,450 m) initial altitude, and an operational capability in 1985 was considered. Three propfan arrangements, wing mounted, conventional horizontal tail aft mounted, and aft fuselage pylon mounted are selected for comparison with the DC-9 Super 80 P&WA JT8D-209 turbofan powered aircraft. The configuration feasibility, aerodynamics, propulsion, structural loads, structural dynamics, sonic fatigue, acoustics, weight maintainability, performance, rough order of magnitude economics, and airline coordination are examined. The effects of alternate cruise Mach number, mission stage lengths, and propfan design characteristics are considered. Recommendations for further study, ground testing, and flight testing are included.

  17. The 400-Hz aircraft power-generation systems: Advancing the baseline

    NASA Technical Reports Server (NTRS)

    Glennon, T.

    1983-01-01

    Today's benchmark system for the Boeing 757/767/A310 airplanes and future trends in hydromechanical aircraft power generating systems are discussed. The 757/767/A310 system represents the commercial state of the art and the direction in which Sundstrand Corp. is headed, particularly in regard to weight reduction. Sundstrand introduced microprocessor control in an in service system in the Boeing 767 and was the first to use databus communications between the controls. Plans to develop this technology are briefly discussed. Alternative ways to produce and use power in aircraft are discussed. The integrated starter drive is discussed.

  18. Flight evaluation of advanced flight control systems and cockpit displays for powered-lift STOL Aircraft

    NASA Technical Reports Server (NTRS)

    Franklin, J. A.; Smith, D. W.; Watson, D. M.; Warner, D. N., Jr.; Innis, R. C.; Hardy, G. H.

    1976-01-01

    A flight research program was conducted to assess the improvements, in longitudinal path control during a STOL approach and landing, that can be achieved with manual and automatic control system concepts and cockpit displays with various degrees of complexity. NASA-Ames powered-lift Augmentor Wing Research Aircraft was used in the research program. Satisfactory flying qualities were demonstrated for selected stabilization and command augmentation systems and flight director combinations. The ability of the pilot to perform precise landings at low touchdown sink rates with a gentle flare maneuver was also achieved. The path-control improvement is considered to be applicable to other powered-lift aircraft configurations.

  19. Simulation of a synergistic six-post motion system on the flight simulator for advanced aircraft at NASA-Ames

    NASA Technical Reports Server (NTRS)

    Bose, S. C.; Parris, B. L.

    1977-01-01

    Motion system drive philosophy and corresponding real-time software have been developed for the purpose of simulating the characteristics of a typical synergistic Six-Post Motion System (SPMS) on the Flight Simulator for Advanced Aircraft (FSAA) at NASA-Ames which is a non-synergistic motion system. This paper gives a brief description of these two types of motion systems and the general methods of producing motion cues of the FSAA. An actuator extension transformation which allows the simulation of a typical SPMS by appropriate drive washout and variable position limiting is described.

  20. Preliminary design study of advanced composite blade and hub and nonmechanical control system for the tilt-rotor aircraft. Volume 2: Project planning data

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Project planning data for a rotor and control system procurement and testing program for modifications to the XV-15 tilt-rotor research demonstrator aircraft is presented. The design, fabrication, and installation of advanced composite blades compatible with the existing hub, an advanced composite hub, and a nonmechanical control system are required.

  1. 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) turboprop engines for single-rotation prop-fans and conceptual designs of pitch change mechanisms for single- and counter-rotation prop-fan application are discussed. The single-rotation gearbox is a split path, in-line configuration. The counter-rotation gearbox is an in-line, differential planetary design. The pitch change mechanisms for both the single- and counter-rotation arrangements are rotary/hydraulic. The advanced technology single-rotation gearbox yields a 2.4 percent improvement in aircraft fuel burn and a one percent improvement in operating cost relative to a current technology gearbox. The 1992 counter-rotation gearbox is 15 percent lighter, 15 percent more reliable, 5 percent lower in cost, and 45 percent lower in maintenance cost than the 1992 single-rotation gearbox. The pitch controls are modular, accessible, and external.

  2. Advanced Fiber Optic-Based Sensing Technology for Unmanned Aircraft Systems

    NASA Technical Reports Server (NTRS)

    Richards, Lance; Parker, Allen R.; Piazza, Anthony; Ko, William L.; Chan, Patrick; Bakalyar, John

    2011-01-01

    This presentation provides an overview of fiber optic sensing technology development activities performed at NASA Dryden in support of Unmanned Aircraft Systems. Examples of current and previous work are presented in the following categories: algorithm development, system development, instrumentation installation, ground R&D, and flight testing. Examples of current research and development activities are provided.

  3. Preliminary design study of advanced composite blade and hub and nonmechanical control system for the tilt-rotor aircraft. Volume 1: Engineering studies

    NASA Technical Reports Server (NTRS)

    Alexander, H. R.; Smith, K. E.; Mcveigh, M. A.; Dixon, P. G.; Mcmanus, B. L.

    1979-01-01

    Composite structures technology is applied in a preliminary design study of advanced technology blades and hubs for the XV-15 tilt rotor research demonstrator aircraft. Significant improvements in XV-15 hover and cruise performance are available using blades designed for compatibility with the existing aircraft, i.e., blade installation would not require modification of the airframe, hub or upper controls. Provision of a low risk nonmechanical control system was also studied, and a development specification is given.

  4. Advanced System Design Requirements for Large and Small Fixed-wing Aerial Application Systems for Agriculture

    NASA Technical Reports Server (NTRS)

    Hinely, J. T., Jr.; Boyles, R. Q., Jr.

    1979-01-01

    Several candidate aircraft configurations were defined over the range of 1000 to 10,000 pounds payload and evaluated over a broad spectrum of agricultural missions. From these studies, baseline design points were selected at 3200 pounds payload for the small aircraft and 7500 pounds for the large aircraft. The small baseline aircraft utilizes a single turboprop powerplant while the large aircraft utilizes two turboprop powerplants. These configurations were optimized for wing loading, aspect ratio, and power loading to provide the best mission economics in representative missions. Wing loading of 20 lb/sq ft was selected for the small aircraft and 25 lb/sq ft for the large aircraft. Aspect ratio of 8 was selected for both aircraft. It was found that a 10% reduction in engine power from the original configurations provided improved mission economics for both aircraft by reducing the cost of the turboprop. Refined configurations incorporate a 675 HP engine in the small aircraft and two 688 HP engines in the large aircraft.

  5. Determination of Turboprop Reduction Gearbox System Fatigue Life and Reliability

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.; Lewicki, David G.; Savage, Michael; Vlcek, Brian L.

    2007-01-01

    Two computational models to determine the fatigue life and reliability of a commercial turboprop gearbox are compared with each other and with field data. These models are (1) Monte Carlo simulation of randomly selected lives of individual bearings and gears comprising the system and (2) two-parameter Weibull distribution function for bearings and gears comprising the system using strict-series system reliability to combine the calculated individual component lives in the gearbox. The Monte Carlo simulation included the virtual testing of 744,450 gearboxes. Two sets of field data were obtained from 64 gearboxes that were first-run to removal for cause, were refurbished and placed back in service, and then were second-run until removal for cause. A series of equations were empirically developed from the Monte Carlo simulation to determine the statistical variation in predicted life and Weibull slope as a function of the number of gearboxes failed. The resultant L(sub 10) life from the field data was 5,627 hr. From strict-series system reliability, the predicted L(sub 10) life was 774 hr. From the Monte Carlo simulation, the median value for the L(sub 10) gearbox lives equaled 757 hr. Half of the gearbox L(sub 10) lives will be less than this value and the other half more. The resultant L(sub 10) life of the second-run (refurbished) gearboxes was 1,334 hr. The apparent load-life exponent p for the roller bearings is 5.2. Were the bearing lives to be recalculated with a load-life exponent p equal to 5.2, the predicted L(sub 10) life of the gearbox would be equal to the actual life obtained in the field. The component failure distribution of the gearbox from the Monte Carlo simulation was nearly identical to that using the strict-series system reliability analysis, proving the compatibility of these methods.

  6. Eagle RTS: A design for a regional transport aircraft

    NASA Technical Reports Server (NTRS)

    Bryer, Paul; Buckles, Jon; Lemke, Paul; Peake, Kirk

    1992-01-01

    This university design project concerns the Eagle RTS (Regional Transport System), a 66 passenger, twin turboprop aircraft with a range of 836 nautical miles. It will operate with a crew of two pilots and two flight attendents. This aircraft will employ the use of aluminum alloys and composite materials to reduce the aircraft weight and increase aerodynamic efficiency. The Eagle RTS will use narrow body aerodynamics with a canard configuration to improve performance. Leading edge technology will be used in the cockpit to improve flight handling and safety. The Eagle RTS propulsion system will consist of two turboprop engines with a total thrust of approximately 6300 pounds, 3150 pounds thrust per engine, for the cruise configuration. The engines will be mounted on the aft section of the aircraft to increase passenger safety in the event of a propeller failure. Aft mounted engines will also increase the overall efficiency of the aircraft by reducing the aircraft's drag. The Eagle RTS is projected to have a takeoff distance of approximately 4700 feet and a landing distance of 6100 feet. These distances will allow the Eagle RTS to land at the relatively short runways of regional airports.

  7. Flight service evaluation of an advanced composite empennage component on commercial transport aircraft. Phase 1: Engineering development

    NASA Technical Reports Server (NTRS)

    Ary, A.; Axtell, C.; Fogg, L.; Jackson, A.; James, A. M.; Mosesian, B.; Vanderwier, J.; Vanhamersveld, J.

    1976-01-01

    The empennage component selected for this program is the vertical fin box of the L-1011 aircraft. The box structure extends from the fuselage production joint to the tip rib and includes the front and rear spars. Various design options were evaluated to arrive at a configuration which would offer the highest potential for satisfying program objectives. The preferred configuration selected consists of a hat-stiffened cover with molded integrally stiffened spars, aluminum trussed composite ribs, and composite miniwich web ribs with integrally molded caps. Material screening tests were performed to select an advanced composite material system for the Advanced Composite Vertical Fin (ACFV) that would meet the program requirements from the standpoint of quality, reproducibility, and cost. Preliminary weight and cost analysis were made, targets established, and tracking plans developed. These include FAA certification, ancillary test program, quality control, and structural integrity control plans.

  8. Fibre Optic Sensors for Structural Health Monitoring of Aircraft Composite Structures: Recent Advances and Applications

    PubMed Central

    Di Sante, Raffaella

    2015-01-01

    In-service structural health monitoring of composite aircraft structures plays a key role in the assessment of their performance and integrity. In recent years, Fibre Optic Sensors (FOS) have proved to be a potentially excellent technique for real-time in-situ monitoring of these structures due to their numerous advantages, such as immunity to electromagnetic interference, small size, light weight, durability, and high bandwidth, which allows a great number of sensors to operate in the same system, and the possibility to be integrated within the material. However, more effort is still needed to bring the technology to a fully mature readiness level. In this paper, recent research and applications in structural health monitoring of composite aircraft structures using FOS have been critically reviewed, considering both the multi-point and distributed sensing techniques. PMID:26263987

  9. Fibre Optic Sensors for Structural Health Monitoring of Aircraft Composite Structures: Recent Advances and Applications.

    PubMed

    Di Sante, Raffaella

    2015-01-01

    In-service structural health monitoring of composite aircraft structures plays a key role in the assessment of their performance and integrity. In recent years, Fibre Optic Sensors (FOS) have proved to be a potentially excellent technique for real-time in-situ monitoring of these structures due to their numerous advantages, such as immunity to electromagnetic interference, small size, light weight, durability, and high bandwidth, which allows a great number of sensors to operate in the same system, and the possibility to be integrated within the material. However, more effort is still needed to bring the technology to a fully mature readiness level. In this paper, recent research and applications in structural health monitoring of composite aircraft structures using FOS have been critically reviewed, considering both the multi-point and distributed sensing techniques.

  10. Fibre Optic Sensors for Structural Health Monitoring of Aircraft Composite Structures: Recent Advances and Applications.

    PubMed

    Di Sante, Raffaella

    2015-01-01

    In-service structural health monitoring of composite aircraft structures plays a key role in the assessment of their performance and integrity. In recent years, Fibre Optic Sensors (FOS) have proved to be a potentially excellent technique for real-time in-situ monitoring of these structures due to their numerous advantages, such as immunity to electromagnetic interference, small size, light weight, durability, and high bandwidth, which allows a great number of sensors to operate in the same system, and the possibility to be integrated within the material. However, more effort is still needed to bring the technology to a fully mature readiness level. In this paper, recent research and applications in structural health monitoring of composite aircraft structures using FOS have been critically reviewed, considering both the multi-point and distributed sensing techniques. PMID:26263987

  11. Sensitivity analysis and multidisciplinary optimization for aircraft design: Recent advances and results

    NASA Technical Reports Server (NTRS)

    Sobieszczanski-Sobieski, Jaroslaw

    1988-01-01

    Optimization by decomposition, complex system sensitivity analysis, and a rapid growth of disciplinary sensitivity analysis are some of the recent developments that hold promise of a quantum jump in the support engineers receive from computers in the quantitative aspects of design. Review of the salient points of these techniques is given and illustrated by examples from aircraft design as a process that combines the best of human intellect and computer power to manipulate data.

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

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  13. Study on utilization of advanced composites in commercial aircraft wing structures, volume 2

    NASA Technical Reports Server (NTRS)

    Sakata, I. F.; Ostrom, R. B.

    1978-01-01

    A plan is defined for a composite wing development effort which will assist commercial transport manufacturers in reaching a level of technology readiness where the utilization of composite wing structure is a cost competitive option for a new aircraft production plan. The recommended development effort consists of two programs: a joint government/industry material development program and a wing structure development program. Both programs are described in detail.

  14. Sensitivity analysis and multidisciplinary optimization for aircraft design - Recent advances and results

    NASA Technical Reports Server (NTRS)

    Sobieszczanski-Sobieski, Jaroslaw

    1988-01-01

    Optimization by decomposition, complex system sensitivity analysis, and a rapid growth of disciplinary sensitivity analysis are some of the recent developments that hold promise of a quantum jump in the support engineers receive from computers in the quantitative aspects of design. Review of the salient points of these techniques is given and illustrated by examples from aircraft design as a process that combines the best of human intellect and computer power to manipulate data.

  15. Effect of advanced location methods on search and rescue duration for general aviation aircraft accidents in the contiguous United States

    NASA Astrophysics Data System (ADS)

    Wallace, Ryan J.

    The purpose of this study was to determine the impact of advanced search and rescue devices and techniques on search duration for general aviation aircraft crashes. The study assessed three categories of emergency locator transmitters, including 121.5 MHz, 406 MHz, and GPS-Assisted 406 MHz devices. The impact of the COSPAS-SARSAT organization ceasing satellite monitoring for 121.5 MHz ELTs in 2009 was factored into the study. Additionally, the effect of using radar forensic analysis and cellular phone forensic search methods were also assessed. The study's data was derived from an Air Force Rescue Coordination Center database and included 365 historical general aviation search and rescue missions conducted between 2006 and 2011. Highly skewed data was transformed to meet normality requirements for parametric testing. The significance of each ELT model was assessed using a combination of Brown-Forsythe Means Testing or Orthogonal Contrast Testing. ANOVA and Brown-Forsythe Means testing was used to evaluate cellular phone and radar forensic search methods. A Spearman's Rho test was used to determine if the use of multiple search methods produced an additive effect in search efficiency. Aircraft which utilized an Emergency Locator Transmitter resulted in a shorter search duration than those which did not use such devices. Aircraft utilizing GPS-Aided 406 MHz ELTs appeared to require less time to locate than if equipped with other ELT models, however, this assessment requires further study due to limited data. Aircraft equipped with 406 MHz ELTs required slightly less time to locate than aircraft equipped with older 121.5 MHz ELTs. The study found no substantial difference in the search durations for 121.5 MHz ELTs monitored by COSPAS-SARSAT verses those which were not. Significance testing revealed that the use of cellular phone forensic data and radar forensic data both resulted in substantially higher mission search durations. Some possible explanations for this

  16. Potential applications of advanced aircraft in developing countries. [Brazil and Indonesia

    NASA Technical Reports Server (NTRS)

    Maddalon, D. V.

    1979-01-01

    Air transportation concepts for movement of cargo in developing countries are reviewed using aicraft which may appear in the future. For certain industrial applications, including mining and forestry, the relative costs of doing the job using different types of aircraft are compared with surface transportation systems. Two developing countries, Brazil and Indonesia, were taken as examples to determine what impact they might have on the aircraft markets of the future. Economic and demographic data on developing countries in general, and Brazil and Indonesia in particular, are reviewed. The concept of an industrial city in a remote area developed around an airport is discussed. It is noted that developing areas generally lack extensive surface transportation systems and that an air transportation system can be implemented in a relatively short time. A developing nation interested in rapid expansion may thus find the role of air cargo far more important than has been true in developed nations. Technological developments which may dramatically increase the performance of agricultural aircraft are also reviewed.

  17. NASA advanced design program. Design and analysis of a radio-controlled flying wing aircraft

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The main challenge of this project was to design an aircraft that will achieve stability while flying without a horizontal tail. The project focused on both the design, analysis and construction of a remotely piloted, elliptical shaped flying wing. The design team was composed of four sub-groups each of which dealt with the different aspects of the design, namely aerodynamics, stability and control, propulsion, and structures. Each member of the team initially researched the background information pertaining to specific facets of the project. Since previous work on this topic was limited, most of the focus of the project was directed towards developing an understanding of the natural instability of the aircraft. Once the design team entered the conceptual stage of the project, a series of compromises had to be made to satisfy the unique requirements of each sub-group. As a result of the numerous calculations and iterations necessary, computers were utilized extensively. In order to visualize the design and layout of the wing, engines and control surfaces, a solid modeling package was used to evaluate optimum design placements. When the design was finalized, construction began with the help of all the members of the project team. The nature of the carbon composite construction process demanded long hours of manual labor. The assembly of the engine systems also required precision hand work. The final product of this project is the Elang, a one-of-a-kind remotely piloted aircraft of composite construction powered by two ducted fan engines.

  18. 76 FR 61255 - Airworthiness Directives; Honeywell International Inc. TPE331 Model Turboprop Engines With...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-04

    ... Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska, and (4) Will... International Inc. TPE331 Model Turboprop Engines With Certain Dixie Aerospace, LLC Main Shaft Bearings AGENCY... shaft bearing part number (P/N) 3108098-1WD, installed. That emergency AD was not published in...

  19. Large-Scale Advanced Prop-Fan (LAP) pitch change actuator and control design report

    NASA Technical Reports Server (NTRS)

    Schwartz, R. A.; Carvalho, P.; Cutler, M. J.

    1986-01-01

    In recent years, considerable attention has been directed toward improving aircraft fuel consumption. Studies have shown that the high inherent efficiency previously demonstrated by low speed turboprop propulsion systems may now be extended to today's higher speed aircraft if advanced high-speed propeller blades having thin airfoils and aerodynamic sweep are utilized. Hamilton Standard has designed a 9-foot diameter single-rotation Large-Scale Advanced Prop-Fan (LAP) which will be tested on a static test stand, in a high speed wind tunnel and on a research aircraft. The major objective of this testing is to establish the structural integrity of large-scale Prop-Fans of advanced construction in addition to the evaluation of aerodynamic performance and aeroacoustic design. This report describes the operation, design features and actual hardware of the (LAP) Prop-Fan pitch control system. The pitch control system which controls blade angle and propeller speed consists of two separate assemblies. The first is the control unit which provides the hydraulic supply, speed governing and feather function for the system. The second unit is the hydro-mechanical pitch change actuator which directly changes blade angle (pitch) as scheduled by the control.

  20. Some advantages of methane in an aircraft gas turbine

    NASA Technical Reports Server (NTRS)

    Graham, R. W.; Glassman, A. J.

    1980-01-01

    Because liquid methane may be obtained from existing natural gas sources or produced synthetically from a range of other hydrocarbon sources (coal, biomass, shale, organic waste), it is considered as an aviation fuel in a simplified cycle analysis of the performance of a turboprop engine intended for operation at Mach 0.8 and 10,688 m altitude. Performance comparisons are given for four cases in which the turbine cooling air is either not cooled or cooled to -111, -222, and -333 K, and the advantages and problems that may be expected from direct use of the cryogenic fuel in turbine cooling are discussed. It is shown that while (1) methane combustion characteristics are appreciably different from those of Jet A fuel and will require the development of different combustor designs, and (2) the safe integration of methane cryotanks into transport aircraft structures poses a major design problem, a highly fuel-efficient turboprop engine fueled by methane appears to be feasible.

  1. Some advantages of methane in an aircraft gas turbine

    NASA Technical Reports Server (NTRS)

    Graham, R. W.; Glassman, A. J.

    1980-01-01

    Liquid methane, which can be manufactured from any of the hydrocarbon sources such as coal, shale biomass, and organic waste considered as a petroleum replacement for aircraft fuels. A simple cycle analysis is carried out for a turboprop engine flying a Mach 0.8 and 10, 688 meters (35,000 ft.) altitude. Cycle performance comparisions are rendered for four cases in which the turbine cooling air is cooled or not cooled by the methane fuel. The advantages and disadvantages of involving the fuel in the turbine cooling system are discussed. Methane combustion characteristics are appreciably different from Jet A and will require different combustor designs. Although a number of similar difficult technical problems exist, a highly fuel efficient turboprop engine burning methane appear to be feasible.

  2. Propeller aircraft interior noise model utilization study and validation

    NASA Astrophysics Data System (ADS)

    Pope, L. D.

    1984-09-01

    Utilization and validation of a computer program designed for aircraft interior noise prediction is considered. The program, entitled PAIN (an acronym for Propeller Aircraft Interior Noise), permits (in theory) predictions of sound levels inside propeller driven aircraft arising from sidewall transmission. The objective of the work reported was to determine the practicality of making predictions for various airplanes and the extent of the program's capabilities. The ultimate purpose was to discern the quality of predictions for tonal levels inside an aircraft occurring at the propeller blade passage frequency and its harmonics. The effort involved three tasks: (1) program validation through comparisons of predictions with scale-model test results; (2) development of utilization schemes for large (full scale) fuselages; and (3) validation through comparisons of predictions with measurements taken in flight tests on a turboprop aircraft. Findings should enable future users of the program to efficiently undertake and correctly interpret predictions.

  3. Propeller aircraft interior noise model utilization study and validation

    NASA Technical Reports Server (NTRS)

    Pope, L. D.

    1984-01-01

    Utilization and validation of a computer program designed for aircraft interior noise prediction is considered. The program, entitled PAIN (an acronym for Propeller Aircraft Interior Noise), permits (in theory) predictions of sound levels inside propeller driven aircraft arising from sidewall transmission. The objective of the work reported was to determine the practicality of making predictions for various airplanes and the extent of the program's capabilities. The ultimate purpose was to discern the quality of predictions for tonal levels inside an aircraft occurring at the propeller blade passage frequency and its harmonics. The effort involved three tasks: (1) program validation through comparisons of predictions with scale-model test results; (2) development of utilization schemes for large (full scale) fuselages; and (3) validation through comparisons of predictions with measurements taken in flight tests on a turboprop aircraft. Findings should enable future users of the program to efficiently undertake and correctly interpret predictions.

  4. Active Combustion Control for Aircraft Gas-Turbine Engines-Experimental Results for an Advanced, Low-Emissions Combustor Prototype

    NASA Technical Reports Server (NTRS)

    DeLaat, John C.; Kopasakis, George; Saus, Joseph R.; Chang, Clarence T.; Wey, Changlie

    2012-01-01

    Lean combustion concepts for aircraft engine combustors are prone to combustion instabilities. Mitigation of instabilities is an enabling technology for these low-emissions combustors. NASA Glenn Research Center s prior activity has demonstrated active control to suppress a high-frequency combustion instability in a combustor rig designed to emulate an actual aircraft engine instability experience with a conventional, rich-front-end combustor. The current effort is developing further understanding of the problem specifically as applied to future lean-burning, very low-emissions combustors. A prototype advanced, low-emissions aircraft engine combustor with a combustion instability has been identified and previous work has characterized the dynamic behavior of that combustor prototype. The combustor exhibits thermoacoustic instabilities that are related to increasing fuel flow and that potentially prevent full-power operation. A simplified, non-linear oscillator model and a more physics-based sectored 1-D dynamic model have been developed to capture the combustor prototype s instability behavior. Utilizing these models, the NASA Adaptive Sliding Phasor Average Control (ASPAC) instability control method has been updated for the low-emissions combustor prototype. Active combustion instability suppression using the ASPAC control method has been demonstrated experimentally with this combustor prototype in a NASA combustion test cell operating at engine pressures, temperatures, and flows. A high-frequency fuel valve was utilized to perturb the combustor fuel flow. Successful instability suppression was shown using a dynamic pressure sensor in the combustor for controller feedback. Instability control was also shown with a pressure feedback sensor in the lower temperature region upstream of the combustor. It was also demonstrated that the controller can prevent the instability from occurring while combustor operation was transitioning from a stable, low-power condition to

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

    NASA Technical Reports Server (NTRS)

    Gilinsky, Mikhail; Morgan, Morris H.; Hardin, Jay C.; Mosiane, Lotlamoreng; Kaushal, Patel; Blankson, Isaiah M.

    2000-01-01

    In this project, we continue to develop the previous joint research between the Fluid Mechanics and Acoustics Laboratory (FM&AL) at Hampton University (HU) and the Jet Noise Team (JNT) at the NASA Langley Research Center (NASA LaRC). The FM&AL was established at Hampton University in June of 1996 and has conducted research under two NASA grants: NAG-1-1835 (1996-99), and NAG-1-1936 (1997-00). In addition, the FM&AL has jointly conducted research with the Central AeroHydrodynamics Institute (TsAGI, Moscow) in Russia under a Civilian Research and Development Foundation (CRDF) grant #RE2-136 (1996-99). The goals of the FM&AL programs are twofold: (1) to improve the working efficiency of the FM&AUs team in generating new innovative ideas and in conducting research in the field of fluid dynamics and acoustics, basically for improvement of supersonic and subsonic aircraft engines, and (2) to attract promising minority students to this research and training and, in cooperation with other HU departments, to teach them basic knowledge in Aerodynamics, Gas Dynamics, and Theoretical and Experimental Methods in Aeroacoustics and Computational Fluid Dynamics (CFD). The research at the HU FM&AL supports reduction schemes associated with the emission of engine pollutants for commercial aircraft and concepts for reduction of observables for military aircraft. These research endeavors relate to the goals of the NASA Strategic Enterprise in Aeronautics concerning the development of environmentally acceptable aircraft. It is in this precise area, where the US aircraft industry, academia, and Government are in great need of trained professionals and which is a high priority goal of the Minority University Research and Education (MUREP) Program, that the HU FM&AL can make its most important contribution. The main achievements for the reporting period in the development of concepts for noise reduction and improvement in efficiency for jet exhaust nozzles and inlets for aircraft engines

  6. Advanced composites structural concepts and materials technologies for primary aircraft structures: Design/manufacturing concept assessment

    NASA Technical Reports Server (NTRS)

    Chu, Robert L.; Bayha, Tom D.; Davis, HU; Ingram, J. ED; Shukla, Jay G.

    1992-01-01

    Composite Wing and Fuselage Structural Design/Manufacturing Concepts have been developed and evaluated. Trade studies were performed to determine how well the concepts satisfy the program goals of 25 percent cost savings, 40 percent weight savings with aircraft resizing, and 50 percent part count reduction as compared to the aluminum Lockheed L-1011 baseline. The concepts developed using emerging technologies such as large scale resin transfer molding (RTM), automatic tow placed (ATP), braiding, out-of-autoclave and automated manufacturing processes for both thermoset and thermoplastic materials were evaluated for possible application in the design concepts. Trade studies were used to determine which concepts carry into the detailed design development subtask.

  7. Interim results of long-term environmental exposures of advanced composites for aircraft applications

    NASA Technical Reports Server (NTRS)

    Pride, R. A.

    1978-01-01

    Interim results from a number of ongoing, long-term environmental effects programs for composite materials are reported. The flight service experience is evaluated for 142 composite aircraft components after more than five years and one million successful component flight hours. Ground-based outdoor exposures of composite material coupons after 3 years of exposure at five sites have reached equilibrium levels of moisture pickup which are predictable. Solar ultraviolet-induced material loss is discussed for these same exposures. No significant degradation has been observed in residual strength for either stressed or unstressed specimens, or for exposures to aviation fuels and fluids.

  8. Advanced cargo aircraft may offer a potential renaissance in freight transportation

    NASA Technical Reports Server (NTRS)

    Morris, Shelby J.; Sawyer, Wallace C.

    1993-01-01

    The increasing demand for air freight transportation has prompted studies of large, aerodynamically efficient cargo-optimized aircraft capable of carrying intermodal containers, which are typically 8 x 8 x 20 ft. Studies have accordingly been conducted within NASA to ascertain the specifications and projected operating costs of such a vehicle, as well as to identify critical, development-pacing technologies. Attention is here given not only to the rather conventional, 10-turbofan engined configuration thus arrived at, but numerous innovative configurations featuring such concepts as spanloading, removable cargo pods, and ground effect.

  9. Atmospheric Effects of Subsonic Aircraft: Interim Assessment Report of the Advanced Subsonic Technology Program

    NASA Technical Reports Server (NTRS)

    Friedl, Randall R. (Editor)

    1997-01-01

    This first interim assessment of the subsonic assessment (SASS) project attempts to summarize concisely the status of our knowledge concerning the impacts of present and future subsonic aircraft fleets. It also highlights the major areas of scientific uncertainty, through review of existing data bases and model-based sensitivity studies. In view of the need for substantial improvements in both model formulations and experimental databases, this interim assessment cannot provide confident numerical predictions of aviation impacts. However, a number of quantitative estimates are presented, which provide some guidance to policy makers.

  10. Cost/benefit analysis of advanced materials technologies for future aircraft turbine engines

    NASA Technical Reports Server (NTRS)

    Bisset, J. W.

    1976-01-01

    The cost/benefits of advance commercial gas turbine materials are described. Development costs, estimated payoffs and probabilities of success are discussed. The materials technologies investigated are: (1) single crystal turbine blades, (2) high strength hot isostatic pressed turbine disk, (3) advanced oxide dispersion strengthened burner liner, (4) bore entry cooled hot isostatic pressed turbine disk, (5) turbine blade tip - outer airseal system, and (6) advance turbine blade alloys.

  11. Aircraft-Induced Hole Punch and Canal Clouds

    NASA Astrophysics Data System (ADS)

    Heymsfield, A. J.; Kennedy, P.; Massie, S. T.; Schmitt, C. G.; Wang, Z.; Haimov, S.; Rangno, A.

    2009-12-01

    The production of holes and channels in altocumulus clouds by two commercial turboprop aircraft is documented for the first time. An unprecedented data set combining in situ measurements from microphysical probes with remote sensing measurements from cloud radar and lidar, all operating from the NSF/NCAR C130 aircraft, as well as ground-based NOAA and CSU radars, is used to describe the radar/lidar properties of a hole punch cloud and channel and the ensuing ice microphysical properties and structure of the ice column that subsequently developed. Ice particle production by commercial turboprop aircraft climbing through clouds much warmer than the regions where contrails are produced has the potential to modify significantly the cloud microphysical properties and effectively seed them under some conditions. Jet aircraft may also be producing hole punch clouds when flying through altocumulus with supercooled droplets at heights lower than their normal cruise altitudes where contrails can form. Commercial aircraft therefore can generate ice and affect the clouds at temperatures as much as 30°C warmer than the -40°C contrail formation threshold temperature.

  12. Computation of wake/exhaust mixing downstream of advanced transport aircraft

    NASA Technical Reports Server (NTRS)

    Quackenbush, Todd R.; Teske, Milton E.; Bilanin, Alan J.

    1993-01-01

    The mixing of engine exhaust with the vortical wake of high speed aircraft operating in the stratosphere can play an important role in the formation of chemical products that deplete atmospheric ozone. An accurate analysis of this type of interaction is therefore necessary as a part of the assessment of the impact of proposed High Speed Civil Transport (HSCT) designs on atmospheric chemistry. This paper describes modifications to the parabolic Navier-Stokes flow field analysis in the UNIWAKE unified aircraft wake model to accommodate the computation of wake/exhaust mixing and the simulation of reacting flow. The present implementation uses a passive chemistry model in which the reacting species are convected and diffused by the fluid dynamic solution but in which the evolution of the species does not affect the flow field. The resulting analysis, UNIWAKE/PCHEM (Passive CHEMistry) has been applied to the analysis of wake/exhaust flows downstream of representative HSCT configurations. The major elements of the flow field model are described, as are the results of sample calculations illustrating the behavior of the thermal exhaust plume and the production of species important to the modeling of condensation in the wake. Appropriate steps for further development of the UNIWAKE/PCHEM model are also outlined.

  13. Advanced piloted aircraft flight control system design methodology. Volume 1: Knowledge base

    NASA Technical Reports Server (NTRS)

    Mcruer, Duane T.; Myers, Thomas T.

    1988-01-01

    The development of a comprehensive and electric methodology for conceptual and preliminary design of flight control systems is presented and illustrated. The methodology is focused on the design stages starting with the layout of system requirements and ending when some viable competing system architectures (feedback control structures) are defined. The approach is centered on the human pilot and the aircraft as both the sources of, and the keys to the solution of, many flight control problems. The methodology relies heavily on computational procedures which are highly interactive with the design engineer. To maximize effectiveness, these techniques, as selected and modified to be used together in the methodology, form a cadre of computational tools specifically tailored for integrated flight control system preliminary design purposes. While theory and associated computational means are an important aspect of the design methodology, the lore, knowledge and experience elements, which guide and govern applications are critical features. This material is presented as summary tables, outlines, recipes, empirical data, lists, etc., which encapsulate a great deal of expert knowledge. Much of this is presented in topical knowledge summaries which are attached as Supplements. The composite of the supplements and the main body elements constitutes a first cut at a a Mark 1 Knowledge Base for manned-aircraft flight control.

  14. Development of Advanced Methods of Structural and Trajectory Analysis for Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Ardema, Mark D.; Windhorst, Robert; Phillips, James

    1998-01-01

    This paper develops a near-optimal guidance law for generating minimum fuel, time, or cost fixed-range trajectories for supersonic transport aircraft. The approach uses a choice of new state variables along with singular perturbation techniques to time-scale decouple the dynamic equations into multiple equations of single order (second order for the fast dynamics). Application of the maximum principle to each of the decoupled equations, as opposed to application to the original coupled equations, avoids the two point boundary value problem and transforms the problem from one of a functional optimization to one of multiple function optimizations. It is shown that such an approach produces well known aircraft performance results such as minimizing the Brequet factor for minimum fuel consumption and the energy climb path. Furthermore, the new state variables produce a consistent calculation of flight path angle along the trajectory, eliminating one of the deficiencies in the traditional energy state approximation. In addition, jumps in the energy climb path are smoothed out by integration of the original dynamic equations at constant load factor. Numerical results performed for a supersonic transport design show that a pushover dive followed by a pullout at nominal load factors are sufficient maneuvers to smooth the jump.

  15. Hover performance tests of baseline metal and Advanced Technology Blade (ATB) rotor systems for the XV-15 tilt rotor aircraft

    NASA Technical Reports Server (NTRS)

    Bartie, K.; Alexander, H.; Mcveigh, M.; Lamon, S.; Bishop, H.

    1986-01-01

    Rotor hover performance data were obtained for two full-scale rotor systems designed for the XV-15 Tilt Rotor Research Aircraft. One rotor employed the rectangular planform metal blades (rotor solidity = 0.089) which were used on the initial flight configuration of the XV-15. The second rotor configuration examined the nonlinear taper, composite-construction, Advanced Technology Blade (ATB), (rotor solidity = 0.10) designed to replace the metal blades on the XV-15. Variations of the baseline ATB tip and cuff shapes were also tested. A new six-component rotor force and moment balance designed to obtain highly accurate data over a broad range of thrust and torque conditions is described. The test data are presented in nondimensional coefficient form for the performance results, and in dimensional form for the steady and alternating loads. Some wake and acoustic data are also shown.

  16. Separation of airborne and structureborne noise radiated by plates constructed of conventional and composite materials with applications for prediction of interior noise paths in propeller driven aircraft. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Mcgary, M. C.

    1986-01-01

    The anticipated application of advanced turboprop propulsion systems and use of composite materials in primary structure is expected to increase the interior noise of future aircraft to unacceptability high levels. The absence of technically and economically feasible noise source-path diagnostic tools has been a primer obstacle in the development of efficient noise control treatments for propeller driven aircraft. A new diagnostic method which permits the separation and prediction of the fully coherent airborne and structureborne components of the sound radiated by plates or thin shells has been developed. Analytical and experimental studies of the proposed method were performed on plates constructed of both conventional and composite materials. The results of the study indicate that the proposed method can be applied to a variety of aircraft materials, could be used in flight, and has fewer encumbrances than the other diagnostic tools currently available. The study has also revealed that the noise radiation of vibrating plates in the low frequency regime due to combined airborne and structureborne inputs possesses a strong synergistic nature. The large influence of the interaction between the airborne and structureborne terms has been hitherto ignored by researchers of aircraft interior noise problems.

  17. Application of advanced technologies to derivatives of current small transport aircraft

    NASA Technical Reports Server (NTRS)

    Renze, P. P.; Terry, J. E.

    1981-01-01

    Mission requirements of the derivative design were the same as the baseline to readily identify the advanced technology benefits achieved. Advanced technologies investigated were in the areas of propulsion, structures and aerodynamics and a direct operating cost benefit analysis conducted to identify the most promising. Engine improvements appear most promising and combined with propeller, airfoil, surface coating and composite advanced technologies give a 21-25 percent DOC savings. A 17 percent higher acquisition cost is offset by a 34 percent savings in fuel used.

  18. Wide range operation of advanced low NOx aircraft gas turbine combustors

    NASA Technical Reports Server (NTRS)

    Roberts, P. B.; Fiorito, R. J.; Butze, H. F.

    1978-01-01

    The paper summarizes the results of an experimental test rig program designed to define and demonstrates techniques which would allow the jet-induced circulation and vortex air blast combustors to operate stably with acceptable emissions at simulated engine idle without compromise to the low NOx emissions under the high-altitude supersonic cruise condition. The discussion focuses on the test results of the key combustor modifications for both the simulated engine idle and cruise conditions. Several range-augmentation techniques are demonstrated that allow the lean-reaction premixed aircraft gas turbine combustor to operate with low NOx emissons at engine cruise and acceptable CO and UHC levels at engine idle. These techniques involve several combinations, including variable geometry and fuel switching designs.

  19. Three-dimensional viscous design methodology for advanced technology aircraft supersonic inlet systems

    NASA Technical Reports Server (NTRS)

    Anderson, B. H.

    1983-01-01

    A broad program to develop advanced, reliable, and user oriented three-dimensional viscous design techniques for supersonic inlet systems, and encourage their transfer into the general user community is discussed. Features of the program include: (1) develop effective methods of computing three-dimensional flows within a zonal modeling methodology; (2) ensure reasonable agreement between said analysis and selective sets of benchmark validation data; (3) develop user orientation into said analysis; and (4) explore and develop advanced numerical methodology.

  20. Advanced prediction technique for the low speed aerodynamics of V/STOL aircraft. Volume 1: Technical discussion

    NASA Technical Reports Server (NTRS)

    Beatty, T. D.; Worthey, M. K.

    1984-01-01

    The V/STOL Aircraft Propulsive Effects (VAPE) computerized prediction method is evaluated. The program analyzes viscous effects, various jet, inlet, and Short TakeOff and Landing (STOL) models, and examines the aerodynamic configurations of V/STOL aircraft.

  1. Cost/benefit studies of advanced materials technologies for future aircraft turbine engines: Materials for advanced turbine engines

    NASA Technical Reports Server (NTRS)

    Stearns, M.; Wilbers, L.

    1982-01-01

    Cost benefit studies were conducted on six advanced materials and processes technologies applicable to commercial engines planned for production in the 1985 to 1990 time frame. These technologies consisted of thermal barrier coatings for combustor and high pressure turbine airfoils, directionally solidified eutectic high pressure turbine blades, (both cast and fabricated), and mixers, tail cones, and piping made of titanium-aluminum alloys. A fabricated titanium fan blisk, an advanced turbine disk alloy with improved low cycle fatigue life, and a long-life high pressure turbine blade abrasive tip and ceramic shroud system were also analyzed. Technologies showing considerable promise as to benefits, low development costs, and high probability of success were thermal barrier coating, directionally solidified eutectic turbine blades, and abrasive-tip blades/ceramic-shroud turbine systems.

  2. Updated Assessment of an Open Rotor Airplane Using an Advanced Blade Design

    NASA Technical Reports Server (NTRS)

    Hendricks, Eric S.; Berton, Jeffrey J.; Haller, William J.; Tong, Michael T.; Guynn, Mark D.

    2013-01-01

    Application of open rotor propulsion systems (historically referred to as "advanced turboprops" or "propfans") to subsonic transport aircraft received significant attention and research in the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Recent volatility in fuel prices and concern for aviation's environmental impact have renewed interest in open rotor propulsion, and revived research by NASA and a number of engine manufacturers. Over the last few years, NASA has revived and developed analysis capabilities to assess aircraft designs with open rotor propulsion systems. These efforts have been described in several previous papers along with initial results from applying these capabilities. The initial results indicated that open rotor engines have the potential to provide large reductions in fuel consumption and emissions. Initial noise analysis indicated that current noise regulations can be met with modern baseline blade designs. Improved blades incorporating low-noise features are expected to result in even lower noise levels. This paper describes improvements to the initial assessment, plus a follow-on study using a more advanced open rotor blade design to power the advanced singleaisle transport. The predicted performance and environmental results of these two advanced open rotor concepts are presented and compared.

  3. Three-dimensional viscous design methodology for advanced technology aircraft supersonic inlet systems

    NASA Technical Reports Server (NTRS)

    Anderson, B. H.

    1984-01-01

    A broad program to develop advanced, reliable, and user oriented three-dimensional viscous design techniques for supersonic inlet systems, and encourage their transfer into the general user community is discussed. Features of the program include: (1) develop effective methods of computing three-dimensional flows within a zonal modeling methodology; (2) ensure reasonable agreement between said analysis and selective sets of benchmark validation data; (3) develop user orientation into said analysis; and (4) explore and develop advanced numerical methodology. Previously announced in STAR as N84-13190

  4. Advanced crew station concepts, displays, and input/output technology for civil aircraft of the future

    NASA Technical Reports Server (NTRS)

    Hatfield, J. J.; Robertson, J. B.; Batson, V. M.

    1979-01-01

    Current efforts on a new Cockpit Avionics Research program are described. The major thrusts of the program presented include: a comparative analysis of advanced display media and development of promising selected media, development of flight display generation techniques, and identification and development of promising I/O technology. In addition, the advanced integrated display concepts described include a 'tunnel in the sky' display and a traffic situation display with associated keyboard. Finally, the Cockpit Avionics Research program is summarized, future research plans are presented, and the need for an expanded program is discussed.

  5. Optimization of a Turboprop UAV for Maximum Loiter and Specific Power Using Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Dinc, Ali

    2016-09-01

    In this study, a genuine code was developed for optimization of selected parameters of a turboprop engine for an unmanned aerial vehicle (UAV) by employing elitist genetic algorithm. First, preliminary sizing of a UAV and its turboprop engine was done, by the code in a given mission profile. Secondly, single and multi-objective optimization were done for selected engine parameters to maximize loiter duration of UAV or specific power of engine or both. In single objective optimization, as first case, UAV loiter time was improved with an increase of 17.5% from baseline in given boundaries or constraints of compressor pressure ratio and burner exit temperature. In second case, specific power was enhanced by 12.3% from baseline. In multi-objective optimization case, where previous two objectives are considered together, loiter time and specific power were increased by 14.2% and 9.7% from baseline respectively, for the same constraints.

  6. Fuel Consumption Reduction and Weight Estimate of an Intercooled-Recuperated Turboprop Engine

    NASA Astrophysics Data System (ADS)

    Andriani, Roberto; Ghezzi, Umberto; Ingenito, Antonella; Gamma, Fausto

    2012-09-01

    The introduction of intercooling and regeneration in a gas turbine engine can lead to performance improvement and fuel consumption reduction. Moreover, as first consequence of the saved fuel, also the pollutant emission can be greatly reduced. Turboprop seems to be the most suitable gas turbine engine to be equipped with intercooler and heat recuperator thanks to the relatively small mass flow rate and the small propulsion power fraction due to the exhaust nozzle. However, the extra weight and drag due to the heat exchangers must be carefully considered. An intercooled-recuperated turboprop engine is studied by means of a thermodynamic numeric code that, computing the thermal cycle, simulates the engine behavior at different operating conditions. The main aero engine performances, as specific power and specific fuel consumption, are then evaluated from the cycle analysis. The saved fuel, the pollution reduction, and the engine weight are then estimated for an example case.

  7. Performance of a Turboprop Engine with Heat Recovery in Off-Design Conditions

    NASA Astrophysics Data System (ADS)

    Andriani, Roberto; Ghezzi, Umberto; Gamma, Fausto; Ingenito, Antonella; Agresta, Antonio

    2013-09-01

    The research for fuel consumption and pollution reduction in new generation aero engines has indicated intercooling and regeneration as very effective methods for this purpose. Hence, different countries have joined their efforts in common research programs, to develop new gas turbine engines able to reduce considerably the fuel consumption and the ambient impact by means of these two techniques. To study their effects on the engine performance and characteristics, a thermodynamic numerical program that simulates the behavior of a turboprop engine with intercooling and regeneration in different operating conditions has been developed. After the parametric study, and the definition of the design conditions, the off-design analysis is carried on, comparing the main characteristics of the intercooled-regenerated turboprop with those of a conventional engine. Then, once a particular mission profile was fixed, the engine performance, in particular the equivalent power, the fuel consumption and the heat exchanger weight were discussed.

  8. Advancing Unmanned Aircraft Sensor Collection and Communication Capabilities with Optical Communications

    NASA Astrophysics Data System (ADS)

    Lukaczyk, T.

    2015-12-01

    Unmanned aircraft systems (UAS) are now being used for monitoring climate change over both land and seas. Their uses include monitoring of cloud conditions and atmospheric composition of chemicals and aerosols due to pollution, dust storms, fires, volcanic activity and air-sea fluxes. Additional studies of carbon flux are important for various ecosystem studies of both marine and terrestrial environments specifically, and can be related to climate change dynamics. Many measurements are becoming more complex as additional sensors become small enough to operate on more widely available small UAS. These include interferometric radars as well as scanning and fan-beam lidar systems which produce data streams even greater than those of high resolution video. These can be used to precisely map surfaces of the earth, ocean or ice features that are important for a variety of earth system studies. As these additional sensor capabilities are added to UAS the ability to transmit data back to ground or ship monitoring sites is limited by traditional wireless communication protocols. We describe results of tests of optical communication systems that provide significantly greater communication bandwidths for UAS, and discuss both the bandwidth and effective range of these systems, as well as their power and weight requirements both for systems on UAS, as well as those of ground-based receiver stations. We justify our additional use of Delay and Disruption Tolerant Networking (DTN) communication protocols with optical communication methods to ensure security and continuity of command and control operations. Finally, we discuss the implications for receiving, geo-referencing, archiving and displaying data streams from sensors communicated via optical communication to better enable real-time anomaly detection and adaptive sampling capabilities using multiple UAS or other unmanned or manned systems.

  9. Unified Aeroacoustics Analysis for High Speed Turboprop Aerodynamics and Noise. Volume 1; Development of Theory for Blade Loading, Wakes, and Noise

    NASA Technical Reports Server (NTRS)

    Hanson, D. B.

    1991-01-01

    A unified theory for the aerodynamics and noise of advanced turboprops are presented. Aerodynamic topics include calculation of performance, blade load distribution, and non-uniform wake flow fields. Blade loading can be steady or unsteady due to fixed distortion, counter-rotating wakes, or blade vibration. The aerodynamic theory is based on the pressure potential method and is therefore basically linear. However, nonlinear effects associated with finite axial induction and blade vortex flow are included via approximate methods. Acoustic topics include radiation of noise caused by blade thickness, steady loading (including vortex lift), and unsteady loading. Shielding of the fuselage by its boundary layer and the wing are treated in separate analyses that are compatible but not integrated with the aeroacoustic theory for rotating blades.

  10. Fiber Optic Control System integration for advanced aircraft. Electro-optic and sensor fabrication, integration, and environmental testing for flight control systems

    NASA Technical Reports Server (NTRS)

    Seal, Daniel W.; Weaver, Thomas L.; Kessler, Bradley L.; Bedoya, Carlos A.; Mattes, Robert E.

    1994-01-01

    This report describes the design, development, and testing of passive fiber optic sensors and a multiplexing electro-optic architecture (EOA) for installation and flight test on a NASA-owned F-18 aircraft. This hardware was developed under the Fiber Optic Control Systems for Advanced Aircraft program, part of a multiyear NASA initiative to design, develop, and demonstrate through flight test 'fly-by-light' systems for application to advanced aircraft flight and propulsion control. This development included the design and production of 10 passive optical sensors and associated multiplexed EOA hardware based on wavelength division multiplexed (WDM) technology. A variety of sensor types (rotary position, linear position, temperature, and pressure) incorporating a broad range of sensor technologies (WDM analog, WDM digital, analog microbend, and fluorescent time rate of decay) were obtained from different manufacturers and functionally integrated with an independently designed EOA. The sensors were built for installation in a variety of aircraft locations, placing the sensors in a variety of harsh environments. The sensors and EOA were designed and built to have the resulting devices be as close as practical to a production system. The integrated system was delivered to NASA for flight testing on a NASA-owned F-18 aircraft. Development and integration testing of the system provided valuable information as to which sensor types were simplest to design and build for a military aircraft environment and which types were simplest to operate with a multiplexed EOA. Not all sensor types met the full range of performance and environmental requirements. EOA development problems provided information on directions to pursue in future fly-by-light flight control development programs. Lessons learned in the development of the EOA and sensor hardware are summarized.

  11. Injection repair of advanced aircraft composites with a high temperature cyanate ester resin

    NASA Astrophysics Data System (ADS)

    Bauer, Amy Elizabeth

    Polymer matrix composites, especially those with carbon fiber reinforcement, are becoming increasingly common in aerospace applications due to their high stiffness to weight ratio, resulting in significant weight and fuel savings on commercial and military aircraft. Despite their excellent properties, carbon fiber composites are often susceptible to damage in the form of delaminations or interlaminar cracking caused by low energy impact or manufacturing defects. Often not easily detectable, delaminations are detrimental to the strength of the composite and can ultimately result in failure of the component. Therefore methods must be developed to repair damaged composites. Injection repair is a procedure that involves injecting a low viscosity resin into the damaged area and subjecting the composite to heat to cure the resin. Currently, injection repairs are rarely used in high temperature applications because of the lack of resins with both low viscosity and high thermal stability. Therefore demonstrating the use of a resin with satisfactory viscosity and Tg requirements would expand the application of injection repairs to more vigorous environments. In the present study, the injection repair method was developed to repair damaged bismaleimide carbon fiber composites that are similar to composites used on several high temperature weapon platforms. Bisphenol E cyanate ester (BECy) was chosen as the injection resin due to having the unique combination of low viscosity and a high glass transition temperature. Cure kinetic studies found an optimum undercure schedule to achieve the maximum T g while avoiding the high temperature postcure. Mechanical and adhesive tests revealed that partially cured BECy had properties superior to that of the fully cured resin. Following the evaluation of the resin, the injection repair procedure and set up were developed. Successful and reproducible repairs were performed on panels pre-damaged through static loading and drop tower impact

  12. 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.

  13. Aircraft community noise impact studies

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The objectives of the study are to: (1) conduct a program to determine the community noise impact of advanced technology engines when installed in a supersonic aircraft, (2) determine the potential reduction of community noise by flight operational techniques for the study aircraft, (3) estimate the community noise impact of the study aircraft powered by suppressed turbojet engines and by advanced duct heating turbofan engines, and (4) compare the impact of the two supersonic designs with that of conventional commercial DC-8 aircraft.

  14. Electro-optic architecture for servicing sensors and actuators in advanced aircraft propulsion systems

    NASA Technical Reports Server (NTRS)

    Poppel, G. L.; Glasheen, W. M.

    1989-01-01

    A detailed design of a fiber optic propulsion control system, integrating favored sensors and electro-optics architecture is presented. Layouts, schematics, and sensor lists describe an advanced fighter engine system model. Components and attributes of candidate fiber optic sensors are identified, and evaluation criteria are used in a trade study resulting in favored sensors for each measurand. System architectural ground rules were applied to accomplish an electro-optics architecture for the favored sensors. A key result was a considerable reduction in signal conductors. Drawings, schematics, specifications, and printed circuit board layouts describe the detailed system design, including application of a planar optical waveguide interface.

  15. Supersonic aerodynamic characteristics of an advanced F-16 derivative aircraft configuration

    NASA Technical Reports Server (NTRS)

    Fox, Mike C.; Forrest, Dana K.

    1993-01-01

    A supersonic wind tunnel investigation was conducted in the NASA Langley Unitary Plan Wind Tunnel on an advanced derivative configuration of the United States Air Force F-16 fighter. Longitudinal and lateral directional force and moment data were obtained at Mach numbers of 1.60 to 2.16 to evaluate basic performance parameters and control effectiveness. The aerodynamic characteristics for the F-16 derivative model were compared with the data obtained for the F-16C model and also with a previously tested generic wing model that features an identical plan form shape and similar twist distribution.

  16. Development of an advanced pitch active control system and a reduced area horizontal tail for a wide-body jet aircraft

    NASA Technical Reports Server (NTRS)

    Guinn, Wiley A.

    1984-01-01

    The development of an advanced pitch active control system (PACS) and a reduced area horizontal tail for a wide-body jet transport (L-1011) with a flying horizontal stabilizer is discussed. The advanced PACS control law design objectives were to provide satisfactory handling qualities for aft c.g. flight conditions to negative static stability margins of 10 percent and to provide good maneuver control column force gradients for nonlinear stability flight conditions. Validity of the control laws were demonstrated by piloted flight simulation tests on the NASA Langley Visual Motion Simulator. Satisfactory handling qualities were actually demonstrated to a negative 20 percent static stability margin. The PACS control laws were mechanized to provide the system architecture that would be suitable for an L-1011 flight test program to a negative stability margin of 3 percent which represents the aft c.g. limits of the aircraft. Reduced area horizontal tail designs of 30 and 38 percent with respect to the L-1011 standard tail were designed, fabricated and wind tunnel tested. Drag reductions and weight savings of the 30 percent smaller tail would provide an L/D benefit of about 2% and the 38% small tail L/D benefit would be about 3 percent. However, forward c.g. limitations would have to be imposed on the aircraft because the maximum horizontal tail lift goal was not achieved and sufficient aircraft nose-up control authority was not available. This limitation would not be required for a properly designed new aircraft.

  17. Nonlinear displacement analysis of advanced propeller structures using NASTRAN

    NASA Technical Reports Server (NTRS)

    Lawrence, C.; Kielb, R. E.

    1984-01-01

    The steady state displacements of a rotating advanced turboprop are computed using the geometrically nonlinear capabilities of COSMIC NASTRAN Rigid Format 4 and MSC NASTRAN Solution 64. A description of the modified Newton-Raphson algorithm used by Solution 64 and the iterative scheme used by Rigid Format 4 is provided. A representative advanced turboprop, SR3, was used for the study. Displacements for SR3 are computed for rotational speeds up to 10,000 rpm. The results show Solution 64 to be superior for computating displacements of flexible rotating structures. This is attributed to its ability to update the displacement dependent centrifugal force during the solution process.

  18. Vibration and aeroelasticity of advanced aircraft wings modeled as thin-walled beams: Dynamics, stability and control

    NASA Astrophysics Data System (ADS)

    Qin, Zhanming

    Based on a refined analytical anisotropic thin-walled beam model, aeroelastic instability, dynamic aeroelastic response, active/passive aeroelastic control of advanced aircraft wings modeled as thin-walled beams are systematically addressed. The refined thin-walled beam model is based on an existing framework of the thin-walled beam model and a couple of non-classical effects that are usually also important are incorporated and the model herein developed is validated against the available experimental, Finite Element Analysis (FEA), Dynamic Finite Element (DFE), and other analytical predictions. The concept of indicial functions is used to develop unsteady aerodynamic model, which broadly encompasses the cases of incompressible, compressible subsonic, compressible supersonic and hypersonic flows. State-space conversion of the indicial function based unsteady aerodynamic model is also developed. Based on the piezoelectric material technology, a worst case control strategy based on the minimax theory towards the control of aeroelastic systems is further developed. Shunt damping within the aeroelastic tailoring environment is also investigated. The major part of this dissertation is organized in the form of self-contained chapters, each of which corresponds to a paper that has been or will be submitted to a journal for publication. In order to fullfil the requirement of having a continuous presentation of the topics, each chapter starts with the purely structural models and is gradually integrated with the involved interactive field disciplines.

  19. Design and Optimization of a Composite Canard Control Surface of an Advanced Fighter Aircraft under Static Loading

    NASA Astrophysics Data System (ADS)

    Shrivastava, Sachin; Mohite, P. M.

    2015-01-01

    The minimization of weight and maximization of payload is an ever challenging design procedure for air vehicles. The present study has been carried out with an objective to redesign control surface of an advanced all-metallic fighter aircraft. In this study, the structure made up of high strength aluminum, titanium and ferrous alloys has been attempted to replace by carbon fiber composite (CFC) skin, ribs and stiffeners. This study presents an approach towards development of a methodology for optimization of first-ply failure index (FI) in unidirectional fibrous laminates using Genetic-Algorithms (GA) under quasi-static loading. The GAs, by the application of its operators like reproduction, cross-over, mutation and elitist strategy, optimize the ply-orientations in laminates so as to have minimum FI of Tsai-Wu first-ply failure criterion. The GA optimization procedure has been implemented in MATLAB and interfaced with commercial software ABAQUS using python scripting. FI calculations have been carried out in ABAQUS with user material subroutine (UMAT). The GA's application gave reasonably well-optimized ply-orientations combination at a faster convergence rate. However, the final optimized sequence of ply-orientations is obtained by tweaking the sequences given by GA's based on industrial practices and experience, whenever needed. The present study of conversion of an all metallic structure to partial CFC structure has led to 12% of weight reduction. Therefore, the approach proposed here motivates designer to use CFC with a confidence.

  20. Redesigning of a Canard Control Surface of an Advanced Fighter Aircraft: Effect on Buckling and Aerodynamic Behavior

    NASA Astrophysics Data System (ADS)

    Shrivastava, Sachin; Mohite, P. M.

    2015-01-01

    A redesign of canard control-surface of an advanced all-metallic fighter aircraft was carried out by using carbon fibre composite (CFC) for ribs and panels. In this study ply-orientations of CFC structure are optimized using a Genetic-Algorithm (GA) with an objective function to have minimum failure index (FI) according to Tsai-Wu failure criterion. The redesigned CFC structure was sufficiently strong to withstand aerodynamic loads from stress and deflection points of view. Now, in the present work CFC canard structure has been studied for its buckling strength in comparison to existing metallic design. In this study, the existing metallic design was found to be weak in buckling. Upon a detailed investigation, it was revealed that there are reported failures in the vicinity of zones where initial buckling modes are excited as predicted by the finite element based buckling analysis. In view of buckling failures, the redesigned CFC structure is sufficiently reinforced with stringers at specific locations. After providing reinforcements against buckling, the twist and the camber variations of the airfoil are checked and compared with existing structure data. Finally, the modal analysis has been carried out to compare the variation in excitation frequency due to material change. The CFC structure thus redesigned is safe from buckling and aerodynamic aspects as well.

  1. Takeoff certification considerations for large subsonic and supersonic transport airplanes using the Ames flight simulator for advanced aircraft

    NASA Technical Reports Server (NTRS)

    Snyder, C. T.; Drinkwater, F. J., III; Fry, E. B.; Forrest, R. D.

    1973-01-01

    Data for use in development of takeoff airworthiness standards for new aircraft designs such as the supersonic transport (SST) and the large wide-body subsonic jet transport are provided. An advanced motion simulator was used to compare the performance and handling characteristics of three representative large jet transports during specific flight certification tasks. Existing regulatory constraints and methods for determining rotation speed were reviewed, and the effects on takeoff performance of variations in rotation speed, pitch attitude, and pitch attitude rate during the rotation maneuver were analyzed. A limited quantity of refused takeoff information was obtained. The aerodynamics, wing loading, and thrust-to-weight ratio of the subject SST resulted in takeoff speeds limited by climb (rather than lift-off) considerations. Take-off speeds based on U.S. subsonic transport requirements were found unacceptable because of the criticality of rotation-abuse effects on one-engine-inoperative climb performance. Adequate safety margin was provided by takeoff speeds based on proposed Anglo-French supersonic transport (TSS) criteria, with the limiting criterion being that takeoff safety speed be at least 1.15 times the one-engine-inoperative zero-rate-of-climb speed. Various observations related to SST certification are presented.

  2. Status of Technological Advancements for Reducing Aircraft Gas Turbine Engine Pollutant Emissions

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1975-01-01

    Combustor test rig results indicate that substantial reductions from current emission levels of carbon monoxide (CO), total unburned hydrocarbons (THC), oxides of nitrogen (NOx), and smoke are achievable by employing varying degrees of technological advancements in combustion systems. Minor to moderate modifications to existing conventional combustors produced significant reductions in CO and THC emissions at engine low power (idle/taxi) operating conditions but did not effectively reduce NOx at engine full power (takeoff) operating conditions. Staged combusiton techniques were needed to simultaneously reduce the levels of all the emissions over the entire engine operating range (from idle to takeoff). Emission levels that approached or were below the requirements of the 1979 EPA standards were achieved with the staged combustion systems and in some cases with the minor to moderate modifications to existing conventional combustion systems. Results from research programs indicate that an entire new generation of combustor technology with extremely low emission levels may be possible in the future.

  3. Development of selected advanced aerodynamics and active control concepts for commercial transport aircraft

    NASA Technical Reports Server (NTRS)

    Taylor, A. B.

    1984-01-01

    Work done under the Energy Efficient Transport project in the field of advanced aerodynamics and active controls is summarized. The project task selections focused on the following: the investigation of long-duct nacelle shape variation on interference drag; the investigation of the adequacy of a simple control law for the elastic modes of a wing; the development of the aerodynamic technology at cruise and low speed of high-aspect-ratio supercritical wings of high performance; and the development of winglets for a second-generation jet transport. All the tasks involved analysis and substantial wind tunnel testing. The winglet program also included flight evaluation. It is considered that the technology base has been built for the application of high-aspect-ratio supercritical wings and for the use of winglets on second-generation transports.

  4. Sensor-Only System Identification for Structural Health Monitoring of Advanced Aircraft

    NASA Technical Reports Server (NTRS)

    Kukreja, Sunil L.; Bernstein, Dennis S.

    2012-01-01

    Environmental conditions, cyclic loading, and aging contribute to structural wear and degradation, and thus potentially catastrophic events. The challenge of health monitoring technology is to determine incipient changes accurately and efficiently. This project addresses this challenge by developing health monitoring techniques that depend only on sensor measurements. Since actively controlled excitation is not needed, sensor-to-sensor identification (S2SID) provides an in-flight diagnostic tool that exploits ambient excitation to provide advance warning of significant changes. S2SID can subsequently be followed up by ground testing to localize and quantify structural changes. The conceptual foundation of S2SID is the notion of a pseudo-transfer function, where one sensor is viewed as the pseudo-input and another is viewed as the pseudo-output, is approach is less restrictive than transmissibility identification and operational modal analysis since no assumption is made about the locations of the sensors relative to the excitation.

  5. A study of engine variable geometry systems for an advanced high subsonic long range commercial aircraft

    NASA Technical Reports Server (NTRS)

    Compagnon, M. A.

    1973-01-01

    Several variable geometry high Mach inlet concepts, aimed at meeting a system noise objective of 15 EPNdB below FAR part 36, for a long range, Mach 0.9 advanced commercial transport are assessed and compared to a fixed geometry inlet with multiple splitters. The effects of a variable exhaust nozzle (mixed exhaust engine) on noise, inlet geometry requirements, and economics are also presented. The best variable geometry inlet configuration identified is a variable cowl design which relies on a high throat Mach number for additional inlet noise suppression only at takeoff, and depends entirely on inlet wall treatment for noise suppression at approach power. Relative economic penalties as a function of noise level are also presented.

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

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  7. An analytical method to predict efficiency of aircraft gearboxes

    NASA Technical Reports Server (NTRS)

    Anderson, N. E.; Loewenthal, S. H.; Black, J. D.

    1984-01-01

    A spur gear efficiency prediction method previously developed by the authors was extended to include power loss of planetary gearsets. A friction coefficient model was developed for MIL-L-7808 oil based on disc machine data. This combined with the recent capability of predicting losses in spur gears of nonstandard proportions allows the calculation of power loss for complete aircraft gearboxes that utilize spur gears. The method was applied to the T56/501 turboprop gearbox and compared with measured test data. Bearing losses were calculated with large scale computer programs. Breakdowns of the gearbox losses point out areas for possible improvement.

  8. Investigation to advance prediction techniques of the low-speed aerodynamics of V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    Maskew, B.; Strash, D.; Nathman, J.; Dvorak, F. A.

    1985-01-01

    A computer program, VSAERO, has been applied to a number of V/STOL configurations with a view to advancing prediction techniques for the low-speed aerodynamic characteristics. The program couples a low-order panel method with surface streamline calculation and integral boundary layer procedures. The panel method--which uses piecewise constant source and doublet panels-includes an iterative procedure for wake shape and models boundary layer displacement effect using the source transpiration technique. Certain improvements to a basic vortex tube jet model were installed in the code prior to evaluation. Very promising results were obtained for surface pressures near a jet issuing at 90 deg from a flat plate. A solid core model was used in the initial part of the jet with a simple entrainment model. Preliminary representation of the downstream separation zone significantly improve the correlation. The program accurately predicted the pressure distribution inside the inlet on the Grumman 698-411 design at a range of flight conditions. Furthermore, coupled viscous/potential flow calculations gave very close correlation with experimentally determined operational boundaries dictated by the onset of separation inside the inlet. Experimentally observed degradation of these operational boundaries between nacelle-alone tests and tests on the full configuration were also indicated by the calculation. Application of the program to the General Dynamics STOL fighter design were equally encouraging. Very close agreement was observed between experiment and calculation for the effects of power on pressure distribution, lift and lift curve slope.

  9. Development of Pneumatic Channel Wing Powered-Lift Advanced Super-STOL Aircraft

    NASA Technical Reports Server (NTRS)

    Englar, Robert J.; Campbell, Bryan A.

    2002-01-01

    The powered-lift Channel Wing concept has been combined with pneumatic Circulation Control aerodynamic and propulsive technology to generate a Pneumatic Channel Wing configuration intended to have Super-STOL or VSTOL capability while eliminating many of the operational problem areas of the original Channel Wing vehicle. A preliminary design study of this pneumatic vehicle based on previous wind-tunnel and flight-test data for the two technologies integrated into a simple Pneumatic Channel Wing (PCW) configuration showed very strong Super-STOL potential. Wind-tunnel development and evaluations of a PCW powered model conducted at Georgia Tech Research Institute (GTRI) have shown substantial lift capabilities for the blown configuration (C(sub L) values of 8.5 to 9.0). Variation in blowing of the channel was shown to be more efficient than variation in propeller thrust. Also revealed was the ability to operate unstalled at very high angles of attack of 40 deg-45 deg, or to achieve very high lift at much lower angle of attack to increase visibility and controllability. In order to provide greater flexibility in Super-STOL takeoffs and landings, the blown model also displayed the ability to interchange thrust and drag by varying blowing without any moving parts. This paper presents these experimental results, discusses variations in the configuration geometry under development, and extends this integrated technology to advanced design studies of PCW-type vehicles.

  10. Advanced Low-Emissions Catalytic-Combustor Program, phase 1. [aircraft gas turbine engines

    NASA Technical Reports Server (NTRS)

    Sturgess, G. J.

    1981-01-01

    Six catalytic combustor concepts were defined, analyzed, and evaluated. Major design considerations included low emissions, performance, safety, durability, installations, operations and development. On the basis of these considerations the two most promising concepts were selected. Refined analysis and preliminary design work was conducted on these two concepts. The selected concepts were required to fit within the combustor chamber dimensions of the reference engine. This is achieved by using a dump diffuser discharging into a plenum chamber between the compressor discharge and the turbine inlet, with the combustors overlaying the prediffuser and the rear of the compressor. To enhance maintainability, the outer combustor case for each concept is designed to translate forward for accessibility to the catalytic reactor, liners and high pressure turbine area. The catalytic reactor is self-contained with air-cooled canning on a resilient mounting. Both selected concepts employed integrated engine-starting approaches to raise the catalytic reactor up to operating conditions. Advanced liner schemes are used to minimize required cooling air. The two selected concepts respectively employ fuel-rich initial thermal reaction followed by rapid quench and subsequent fuel-lean catalytic reaction of carbon monoxide, and, fuel-lean thermal reaction of some fuel in a continuously operating pilot combustor with fuel-lean catalytic reaction of remaining fuel in a radially-staged main combustor.

  11. Application of variable-sweep wings to commuter aircraft

    NASA Technical Reports Server (NTRS)

    Robins, A. W.; Beissner, F. L., Jr.; Lovell, W. A.; Price, J. E.; Turriiziani, R. V.; Washburn, F. F.

    1983-01-01

    The effects of using variable-sweep wings on the riding quality and mission-performance characteristics of commuter-type aircraft were studied. A fixed-wing baseline vehicle and a variable-sweep version of the baseline were designed and evaluated. Both vehicles were twin-turboprop, pressurized-cabin, 30-passenger commuter aircraft with identical mission requirements. Mission performance was calculated with and without various ride-quality constraints for several combinations of cruise altitude and stage lengths. The variable-sweep aircraft had a gross weight of almost four percent greater than the fixed-wing baseline in order to meet the design-mission requirements. In smooth air, the variable sweep configuration flying with low sweep had a two to three percent fuel-use penalty. However, the imposition of quality constraints in rough air can result in advantages in both fuel economy and flight time for the variable-sweep vehicle flying with high sweep.

  12. Advanced prediction technique for the low speed aerodynamics of V/STOL aircraft. Volume 2: User's manual

    NASA Technical Reports Server (NTRS)

    Beatty, T. D.; Worthey, M. K.

    1984-01-01

    A computerized prediction method known as the Vought V/STOL Aircraft Propulsive Effects computer program (VAPE) for propulsive induced forces and moments in transition and Short TakeOff and Landing (STOL) flight is improved and evaluated. The VAPE program is capable of evaluating: (1) effects of relative wind about an aircraft, (2) effects of propulsive lift jet entrainment, vorticity and flow blockage, (3) effects of engine inlet flow on the aircraft flow field, (4) engine inlet forces and moments including inlet separation, (5) ground effects in the STOL region of flight, and (6) viscous effects on lifting surfaces.

  13. Flight evaluation of advanced controls and displays for transition and landing on the NASA V/STOL systems research aircraft

    NASA Technical Reports Server (NTRS)

    Franklin, James A.; Stortz, Michael W.; Borchers, Paul F.; Moralez, Ernesto, III

    1996-01-01

    Flight experiments were conducted on Ames Research Center's V/STOL Systems Research Aircraft (VSRA) to assess the influence of advanced control modes and head-up displays (HUD's) on flying qualities for precision approach and landing operations. Evaluations were made for decelerating approaches to hover followed by a vertical landing and for slow landings for four control/display mode combinations: the basic YAV-8B stability augmentation system; attitude command for pitch, roll, and yaw; flightpath/acceleration command with translational rate command in the hover; and height-rate damping with translational-rate command. Head-up displays used in conjunction with these control modes provided flightpath tracking/pursuit guidance and deceleration commands for the decelerating approach and a mixed horizontal and vertical presentation for precision hover and landing. Flying qualities were established and control usage and bandwidth were documented for candidate control modes and displays for the approach and vertical landing. Minimally satisfactory bandwidths were determined for the translational-rate command system. Test pilot and engineer teams from the Naval Air Warfare Center, the Boeing Military Airplane Group, Lockheed Martin, McDonnell Douglas Aerospace, Northrop Grumman, Rolls-Royce, and the British Defense Research Agency participated in the program along with NASA research pilots from the Ames and Lewis Research Centers. The results, in conjunction with related ground-based simulation data, indicate that the flightpath/longitudinal acceleration command response type in conjunction with pursuit tracking and deceleration guidance on the HUD would be essential for operation to instrument minimums significantly lower than the minimums for the AV-8B. It would also be a superior mode for performing slow landings where precise control to an austere landing area such as a narrow road is demanded. The translational-rate command system would reduce pilot workload for

  14. Effect of advanced aircraft noise reduction technology on the 1990 projected noise environment around Patrick Henry Airport. [development of noise exposure forecast contours for projected traffic volume and aircraft types

    NASA Technical Reports Server (NTRS)

    Cawthorn, J. M.; Brown, C. G.

    1974-01-01

    A study has been conducted of the future noise environment of Patric Henry Airport and its neighboring communities projected for the year 1990. An assessment was made of the impact of advanced noise reduction technologies which are currently being considered. These advanced technologies include a two-segment landing approach procedure and aircraft hardware modifications or retrofits which would add sound absorbent material in the nacelles of the engines or which would replace the present two- and three-stage fans with a single-stage fan of larger diameter. Noise Exposure Forecast (NEF) contours were computed for the baseline (nonretrofitted) aircraft for the projected traffic volume and fleet mix for the year 1990. These NEF contours are presented along with contours for a variety of retrofit options. Comparisons of the baseline with the noise reduction options are given in terms of total land area exposed to 30 and 40 NEF levels. Results are also presented of the effects on noise exposure area of the total number of daily operations.

  15. Aircraft System Analysis of Technology Benefits to Civil Transport Rotorcraft

    NASA Technical Reports Server (NTRS)

    Wilkerson, Joseph B.; Smith, Roger L.

    2008-01-01

    sized for a representative civil passenger transport mission, using current technology. Individual advanced technologies are quantified and applied to resize the aircraft, thereby quantifying the net benefit of that technology to the rotorcraft. Estimates of development cost, production cost and operating and support costs are made with a commercial cost estimating program, calibrated to Boeing products with adjustments for future civil production processes. A cost metric of cash direct operating cost per available seat-mile (DOC ASM) is used to compare the cost benefit of the technologies. The same metric is used to compare results with turboprop operating costs. Reduced engine SFC was the most advantageous advanced technology for both rotorcraft concepts. Structural weight reduction was the second most beneficial technology, followed by advanced drive systems and then by technology for rotorcraft performance. Most of the technologies evaluated in this report should apply similarly to conventional helicopters. The implicit assumption is that resources will become available to mature the technologies for fullscale production aircraft. That assumption is certainly the weak link in any forecast of future possibilities. The analysis serves the purpose of identifying which technologies offer the most potential benefit, and thus the ones that should receive the highest priority for continued development. This study directly addressed the following NASA Subsonic Rotary Wing (SRW) subtopics: SR W.4.8.I.J Establish capability for rotorcraft system analysis and SRW. 4.8.I.4 Conduct limited technology benefit assessment on baseline rotorcraft configurations.

  16. Lightweight sidewalls for aircraft interior noise control

    NASA Technical Reports Server (NTRS)

    May, D. N.; Plotkin, K. J.; Selden, R. G.; Sharp, B. H.

    1985-01-01

    A theoretical and experimental study was performed to devise lightweight sidewalls for turboprop aircraft. Seven concepts for new sidewalls were analyzed and tested for noise reduction using flat panels of 1.2 m x 1.8 m (4 ft x 6 ft), some of which were aircraft-type constructions and some of which were simpler, easier-to-construct panels to test the functioning of an acoustic principle. Aircraft-application sidewalls were then conceived for each of the seven concepts, and were subjectively evaluated for their ability to meet aircraft nonacoustic design requirements. As a result of the above, the following sidewall concepts were recommended for further investigation: a sidewall in which the interior cavity is vented to ceiling and underfloor areas; sidewalls with wall-mounted resonators, one having a conventional trim panel and one a limp one; and a sidewall with a stiff outer wall and a limp trim panel. These sidewalls appear to promise lower weights than conventional sidewalls adjusted to meet similar acoustic requirements, and further development may prove them to be practical.

  17. 76 FR 45211 - Airworthiness Directives; Honeywell International Inc. TPE331-10 and TPE331-11 Series Turboprop...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... turboprop engines, was published in the Federal Register on June 22, 2010 (75 FR 35354). The proposed rule... Flexibility Act, or DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). List of Subjects... June 22, 2010 (75 FR 35354), is withdrawn. Issued in Burlington, Massachusetts, on July 22, 2011....

  18. Progress in aircraft design since 1903

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Significant developments in aviation history are documented to show the advancements in aircraft design which have taken place since 1903. Each aircraft is identified according to the manufacturer, powerplant, dimensions, normal weight, and typical performance. A narrative summary of the major accomplishments of the aircraft is provided. Photographs of each aircraft are included.

  19. A maintenance model for k-out-of-n subsystems aboard a fleet of advanced commercial aircraft

    NASA Technical Reports Server (NTRS)

    Miller, D. R.

    1978-01-01

    Proposed highly reliable fault-tolerant reconfigurable digital control systems for a future generation of commercial aircraft consist of several k-out-of-n subsystems. Each of these flight-critical subsystems will consist of n identical components, k of which must be functioning properly in order for the aircraft to be dispatched. Failed components are recoverable; they are repaired in a shop. Spares are inventoried at a main base where they may be substituted for failed components on planes during layovers. Penalties are assessed when failure of a k-out-of-n subsystem causes a dispatch cancellation or delay. A maintenance model for a fleet of aircraft with such control systems is presented. The goals are to demonstrate economic feasibility and to optimize.

  20. NASA advanced design program: Analysis, design, and construction of a solar powered aircraft. B.S. Thesis

    NASA Technical Reports Server (NTRS)

    Chan, Agnes; Conley, Kristin; Javorski, Christian T.; Cheung, Kwok-Hung; Crivelli, Paul M.; Torrey, Nancy P.; Traver, Michael L.

    1992-01-01

    Increase in energy demands coupled with rapid depletion of natural energy resources have deemed solar energy as the most logical alternative source of power. The major objective of this project was to build a solar powered remotely controlled aircraft to demonstrate the feasibility of solar energy as an effective, alternate source of power. The final design was optimized for minimum weight and maximum strength of the structure. These design constraints necessitated a carbon fiber composite structure. Surya is a lightweight, durable aircraft capable of achieving level flight powered entirely by solar cells.

  1. New-generation short-haul airliner uses advanced technology

    SciTech Connect

    Sanator, R.J.; Honczarenko, G.

    1982-06-01

    The Saab-Fairchild 340 is a twin-engined, low-wing, 34-passenger pressurized turboprop airplane. It incorporates a modern fuel efficient propulsion system and a new advanced technology wing, resulting in a new-generation airliner for the short-haul market.

  2. Alloy design for aircraft engines

    NASA Astrophysics Data System (ADS)

    Pollock, Tresa M.

    2016-08-01

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

  3. Flight Test of ASAC Aircraft Interior Noise Control System

    NASA Technical Reports Server (NTRS)

    Palumbo, Dan; Cabell, Ran; Cline, John; Sullivan, Brenda

    1999-01-01

    A flight test is described in which an active structural/acoustic control system reduces turboprop induced interior noise on a Raytheon Aircraft Company 1900D airliner. Control inputs to 21 inertial force actuators were computed adaptively using a transform domain version of the multichannel filtered-X LMS algorithm to minimize the mean square response of 32 microphones. A combinatorial search algorithm was employed to optimize placement of the force actuators on the aircraft frame. Both single frequency and multi-frequency results are presented. Reductions of up to 15 dB were obtained at the blade passage frequency (BPF) during single frequency control tests. Simultaneous reductions of the BPF and next 2 harmonics of 10 dB, 2.5 dB and 3.0 dB, were obtained in a multi-frequency test.

  4. Evaluation of installed performance of a wing-tip-mounted pusher turboprop on a semispan wing

    NASA Technical Reports Server (NTRS)

    Patterson, James C., Jr.; Bartlett, Glynn R.

    1987-01-01

    An exploratory investigation has been conducted at the Langley Research Center to determine the effect of a wing-tip-mounted pusher turboprop on the aerodynamic characteristics of a semispan wing. Tests were conducted on a semispan model with an upswept, untapered wing and an airdriven motor that powered an SR-2 high-speed propeller located on the tip of the wing as a pusher propeller. All tests were conducted at a Mach number of 0.70 over an angle-of-attack range from approximately -2 to 4 deg at a Reynolds number of 3.82 x 10 to the 6th based on the wing reference chord of 13 in. The data indicate that, as a result of locating the propeller behind the wing trailing edge at the wing tip in the crossflow of the wing-tip vortex, it is possible to improve propeller performance and simultaneously reduce the lift-induced drag.

  5. Installed nacelle drag-improvement tests of an M = 0.8 turboprop transport configuration

    NASA Technical Reports Server (NTRS)

    Levin, A. D.; Smith, R. C.

    1983-01-01

    An unpowered semispan model of a representative turboprop configuration was tested to determine the effect of configuration modifications on the the nonmetric body and wing juncture. It is indicated that the jet off nacelle-installation drag can be approximately 25% of the cruise drag. However, the losses can be reduced to 17% by changes to the wing leading edge and nacelle intersection. Comparison of test results from a semispan nonmetric fuselage model with those from a full span metric fuselage show differences in angles of attack produced the same lift. It is found that the constant lift drag rise of the semispan model is higher because of the increased angle of attack to achieve the same lift.

  6. An experimental evaluation of S-duct inlet-diffuser configurations for turboprop offset gearbox applications

    NASA Technical Reports Server (NTRS)

    Mcdill, Paul L.

    1986-01-01

    A test program, utilizing a large scale model, was run in the NASA Lewis Research Center 10- by 10-ft wind tunnel to examine the influence on performance of design parameters of turboprop S-duct inlet/diffuser systems. The parametric test program investigated inlet lip thickness, inlet/diffuser cross-sectional geometry, throat design Mach number, and shaft fairing shape. The test program was run at angles of attack to 15 deg and tunnel Mach numbers to 0.35. Results of the program indicate that current design techniques can be used to design inlet/diffuser systems with acceptable total pressure recovery, but several of the design parameters, notably lip thickness (contraction ratio) and shaft fairing cross section, must be optimized to prevent excessive distortion at the compressor face.

  7. Design, ancillary testing, analysis and fabrication data for the advanced composite stabilizer for Boeing 737 aircraft, volume 2

    NASA Technical Reports Server (NTRS)

    Aniversario, R. B.; Harvey, S. T.; Mccarty, J. E.; Parsons, J. T.; Peterson, D. C.; Pritchett, L. D.; Wilson, D. R.; Wogulis, E. R.

    1982-01-01

    Results of tests conducted to demonstrate that composite structures save weight, possess long term durability, and can be fabricated at costs competitive with conventional metal structures are presented with focus on the use of graphite-epoxy in the design of a stabilizer for the Boeing 737 aircraft. Component definition, materials evaluation, material design properties, and structural elements tests are discussed. Fabrication development, as well as structural repair and inspection are also examined.

  8. An integrated computer-program-system for the preliminary design of advanced hypersonic aircraft (PrADO-Hy)

    NASA Astrophysics Data System (ADS)

    Kossira, H.; Bardenhagen, A.; Heinze, W.

    The design program system PrADO-Hy (Preliminary Aircraft Design and Optimization - Hypersonic) for computer-aided conceptional hypersonic aircraft design, developed by the Institute of Aircraft Design and Structural Mechanics (IFL, TU Braunschweig), is introduced. The modular program simulates, controlled by a data management system, in its kernel the design process with the interactions between the different disciplines (aerodynamics, propulsion, structure, flight mechanics, etc.). The design process is superimposed by a multivariable optimization loop. This paper describes the organization of the PrADO system, the data management technique, and as an example of the program library the weight and balance module for the estimation of structural mass. The practical application and the capabilities of the program system are demonstrated by a design study of a TSTO (two-stage-to-orbit) vehicle, which should transfer a space payload of 3.3 tons to a low-earth-orbit (80 km/450 km). The computational results of some investigations will be presented.

  9. Advanced turboprop noise prediction: Development of a code at NASA Langley based on recent theoretical results

    NASA Technical Reports Server (NTRS)

    Farassat, F.; Dunn, M. H.; Padula, S. L.

    1986-01-01

    The development of a high speed propeller noise prediction code at Langley Research Center is described. The code utilizes two recent acoustic formulations in the time domain for subsonic and supersonic sources. The structure and capabilities of the code are discussed. Grid size study for accuracy and speed of execution on a computer is also presented. The code is tested against an earlier Langley code. Considerable increase in accuracy and speed of execution are observed. Some examples of noise prediction of a high speed propeller for which acoustic test data are available are given. A brisk derivation of formulations used is given in an appendix.

  10. Predicted and measured boundary layer refraction for advanced turboprop propeller noise

    NASA Technical Reports Server (NTRS)

    Dittmar, James H.; Krejsa, Eugene A.

    1990-01-01

    Currently, boundary layer refraction presents a limitation to the measurement of forward arc propeller noise measured on an acoustic plate in the NASA Lewis 8- by 6-Foot Supersonic Wind Tunnel. The use of a validated boundary layer refraction model to adjust the data could remove this limitation. An existing boundary layer refraction model is used to predict the refraction for cases where boundary layer refraction was measured. In general, the model exhibits the same qualitative behavior as the measured refraction. However, the prediction method does not show quantitative agreement with the data. In general, it overpredicts the amount of refraction for the far forward angles at axial Mach number of 0.85 and 0.80 and underpredicts the refraction at axial Mach numbers of 0.75 and 0.70. A more complete propeller source description is suggested as a way to improve the prediction method.

  11. Large-Scale Advanced Prop-Fan (LAP)

    NASA Technical Reports Server (NTRS)

    Degeorge, C. L.

    1988-01-01

    In recent years, considerable attention has been directed toward improving aircraft fuel efficiency. Analytical studies and research with wind tunnel models have demonstrated that the high inherent efficiency of low speed turboprop propulsion systems may now be extended to the Mach .8 flight regime of today's commercial airliners. This can be accomplished with a propeller, employing a large number of thin highly swept blades. The term Prop-Fan has been coined to describe such a propulsion system. In 1983 the NASA-Lewis Research Center contracted with Hamilton Standard to design, build and test a near full scale Prop-Fan, designated the Large Scale Advanced Prop-Fan (LAP). This report provides a detailed description of the LAP program. The assumptions and analytical procedures used in the design of Prop-Fan system components are discussed in detail. The manufacturing techniques used in the fabrication of the Prop-Fan are presented. Each of the tests run during the course of the program are also discussed and the major conclusions derived from them stated.

  12. Toward improved durability in advanced aircraft engine hot sections; Proceedings of the Thirty-third ASME International Gas Turbine and Aeroengine Congress and Exposition, Amsterdam, Netherlands, June 5-9, 1988

    NASA Technical Reports Server (NTRS)

    Sokolowski, Daniel E. (Editor)

    1988-01-01

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

  13. Modeling Programs Increase Aircraft Design Safety

    NASA Technical Reports Server (NTRS)

    2012-01-01

    Flutter may sound like a benign word when associated with a flag in a breeze, a butterfly, or seaweed in an ocean current. When used in the context of aerodynamics, however, it describes a highly dangerous, potentially deadly condition. Consider the case of the Lockheed L-188 Electra Turboprop, an airliner that first took to the skies in 1957. Two years later, an Electra plummeted to the ground en route from Houston to Dallas. Within another year, a second Electra crashed. In both cases, all crew and passengers died. Lockheed engineers were at a loss as to why the planes wings were tearing off in midair. For an answer, the company turned to NASA s Transonic Dynamics Tunnel (TDT) at Langley Research Center. At the time, the newly renovated wind tunnel offered engineers the capability of testing aeroelastic qualities in aircraft flying at transonic speeds near or just below the speed of sound. (Aeroelasticity is the interaction between aerodynamic forces and the structural dynamics of an aircraft or other structure.) Through round-the-clock testing in the TDT, NASA and industry researchers discovered the cause: flutter. Flutter occurs when aerodynamic forces acting on a wing cause it to vibrate. As the aircraft moves faster, certain conditions can cause that vibration to multiply and feed off itself, building to greater amplitudes until the flutter causes severe damage or even the destruction of the aircraft. Flutter can impact other structures as well. Famous film footage of the Tacoma Narrows Bridge in Washington in 1940 shows the main span of the bridge collapsing after strong winds generated powerful flutter forces. In the Electra s case, faulty engine mounts allowed a type of flutter known as whirl flutter, generated by the spinning propellers, to transfer to the wings, causing them to vibrate violently enough to tear off. Thanks to the NASA testing, Lockheed was able to correct the Electra s design flaws that led to the flutter conditions and return the

  14. Aircraft Contrails

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Captured in this scene is a series of aircraft contrails in a high traffic region over the northern Gulf of Mexico (27.0N, 85.5W). Contrails are caused by the hot engine exhaust of high flying aircraft interacting with moisture in the cold upper atmosphere and are common occurrances of high flying aircraft.

  15. In-flight near- and far-field acoustic data measured on the Propfan Test Assessment (PTA) testbed and with an adjacent aircraft

    NASA Astrophysics Data System (ADS)

    Woodward, Richard P.; Loeffler, Irvin J.

    1993-04-01

    Flight tests to define the far-field tone source at cruise conditions were completed on the full-scale SR-7L advanced turboprop that was installed on the left wing of a Gulfstream 2 aircraft. This program, designated Propfan Test Assessment (PTA), involved aeroacoustic testing of the propeller over a range of test conditions. These measurements defined source levels for input into long-distance propagation models to predict en route noise. In-flight data were taken for seven test cases. Near-field acoustic data were taken on the Gulfstream fuselage and on a microphone boom that was mounted on the Gulfstream wing outboard of the propeller. Far-field acoustic data were taken by an acoustically instrumented Learjet that flew in formation with the Gulfstream. These flight tests were flown from El Paso, Texas, and from the NASA Lewis Research Center. A comprehensive listing of the aeroacoustic results from these flight tests which may be used for future analysis are presented.

  16. In-flight near- and far-field acoustic data measured on the Propfan Test Assessment (PTA) testbed and with an adjacent aircraft

    NASA Technical Reports Server (NTRS)

    Woodward, Richard P.; Loeffler, Irvin J.

    1993-01-01

    Flight tests to define the far-field tone source at cruise conditions were completed on the full-scale SR-7L advanced turboprop that was installed on the left wing of a Gulfstream 2 aircraft. This program, designated Propfan Test Assessment (PTA), involved aeroacoustic testing of the propeller over a range of test conditions. These measurements defined source levels for input into long-distance propagation models to predict en route noise. In-flight data were taken for seven test cases. Near-field acoustic data were taken on the Gulfstream fuselage and on a microphone boom that was mounted on the Gulfstream wing outboard of the propeller. Far-field acoustic data were taken by an acoustically instrumented Learjet that flew in formation with the Gulfstream. These flight tests were flown from El Paso, Texas, and from the NASA Lewis Research Center. A comprehensive listing of the aeroacoustic results from these flight tests which may be used for future analysis are presented.

  17. Advanced piloted aircraft flight control system design methodology. Volume 2: The FCX flight control design expert system

    NASA Technical Reports Server (NTRS)

    Myers, Thomas T.; Mcruer, Duane T.

    1988-01-01

    The development of a comprehensive and electric methodology for conceptual and preliminary design of flight control systems is presented and illustrated. The methodology is focused on the design states starting with the layout of system requirements and ending when some viable competing system architectures (feedback control structures) are defined. The approach is centered on the human pilot and the aircraft as both the sources of, and the keys to the solution of, many flight control problems. The methodology relies heavily on computational procedures which are highly interactive with the design engineer. To maximize effectiveness, these techniques, as selected and modified to be used together in the methodology, form a cadre of computational tools specifically tailored for integrated flight control system preliminary design purposes. The FCX expert system as presently developed is only a limited prototype capable of supporting basic lateral-directional FCS design activities related to the design example used. FCX presently supports design of only one FCS architecture (yaw damper plus roll damper) and the rules are largely focused on Class IV (highly maneuverable) aircraft. Despite this limited scope, the major elements which appear necessary for application of knowledge-based software concepts to flight control design were assembled and thus FCX represents a prototype which can be tested, critiqued and evolved in an ongoing process of development.

  18. Use of optimization to predict the effect of selected parameters on commuter aircraft performance

    NASA Technical Reports Server (NTRS)

    Wells, V. L.; Shevell, R. S.

    1982-01-01

    An optimizing computer program determined the turboprop aircraft with lowest direct operating cost for various sets of cruise speed and field length constraints. External variables included wing area, wing aspect ratio and engine sea level static horsepower; tail sizes, climb speed and cruise altitude were varied within the function evaluation program. Direct operating cost was minimized for a 150 n.mi typical mission. Generally, DOC increased with increasing speed and decreasing field length but not by a large amount. Ride roughness, however, increased considerably as speed became higher and field length became shorter.

  19. Evaluation of Flying Qualities and Guidance Displays for an Advanced Tilt-Wing STOL Transport Aircraft in Final Approach and Landing

    NASA Technical Reports Server (NTRS)

    Frost, Chad R.; Franklin, James A.; Hardy, Gordon H.

    2002-01-01

    A piloted simulation was performed on the Vertical Motion Simulator at NASA Ames Research Center to evaluate flying qualities of a tilt-wing Short Take-Off and Landing (STOL) transport aircraft during final approach and landing. The experiment was conducted to assess the design s handling qualities, and to evaluate the use of flightpath-centered guidance for the precision approach and landing tasks required to perform STOL operations in instrument meteorological conditions, turbulence, and wind. Pilots rated the handling qualities to be satisfactory for all operations evaluated except those encountering extreme crosswinds and severe windshear; even in these difficult meteorological conditions, adequate handling qualities were maintained. The advanced flight control laws and guidance displays provided consistent performance and precision landings.

  20. Airline return-on-investment model for technology evaluation. [computer program to measure economic value of advanced technology applied to passenger aircraft

    NASA Technical Reports Server (NTRS)

    1974-01-01

    This report presents the derivation, description, and operating instructions for a computer program (TEKVAL) which measures the economic value of advanced technology features applied to long range commercial passenger aircraft. The program consists of three modules; and airplane sizing routine, a direct operating cost routine, and an airline return-on-investment routine. These modules are linked such that they may be operated sequentially or individually, with one routine generating the input for the next or with the option of externally specifying the input for either of the economic routines. A very simple airplane sizing technique was previously developed, based on the Brequet range equation. For this program, that sizing technique has been greatly expanded and combined with the formerly separate DOC and ROI programs to produce TEKVAL.

  1. Application of selected advanced technologies to high performance, single-engine, business airplanes

    NASA Technical Reports Server (NTRS)

    Domack, C. S.; Martin, G. L.

    1984-01-01

    Improvements in performance and fuel efficiency are evaluated for five new configurations of a six place, single turboprop, business airplane derived from a conventional, aluminum construction baseline aircraft. Results show the greatest performance gains for enhancements in natural laminar flow. A conceptual diesel engine provides greater fuel efficiency but reduced performance. Less significant effects are produced by the utilization of composite materials construction or by reconfiguration from tractor to pusher propeller installation.

  2. Advanced composites structural concepts and materials technologies for primary aircraft structures. Structural response and failure analysis: ISPAN modules users manual

    NASA Technical Reports Server (NTRS)

    Hairr, John W.; Huang, Jui-Ten; Ingram, J. Edward; Shah, Bharat M.

    1992-01-01

    The ISPAN Program (Interactive Stiffened Panel Analysis) is an interactive design tool that is intended to provide a means of performing simple and self contained preliminary analysis of aircraft primary structures made of composite materials. The program combines a series of modules with the finite element code DIAL as its backbone. Four ISPAN Modules were developed and are documented. These include: (1) flat stiffened panel; (2) curved stiffened panel; (3) flat tubular panel; and (4) curved geodesic panel. Users are instructed to input geometric and material properties, load information and types of analysis (linear, bifurcation buckling, or post-buckling) interactively. The program utilizing this information will generate finite element mesh and perform analysis. The output in the form of summary tables of stress or margins of safety, contour plots of loads or stress, and deflected shape plots may be generalized and used to evaluate specific design.

  3. Technical Seminar: "Progress in Aircraft Noise Research"""

    NASA Video Gallery

    Advances in aircraft noise research can be attributed to the development of new technologies and sustained collaboration with industry, universities and government organizations. Emphasis has been ...

  4. Trust Control of VTOL Aircraft Part Deux

    NASA Technical Reports Server (NTRS)

    Dugan, Daniel C.

    2014-01-01

    Thrust control of Vertical Takeoff and Landing (VTOL) aircraft has always been a debatable issue. In most cases, it comes down to the fundamental question of throttle versus collective. Some aircraft used throttle(s), with a fore and aft longitudinal motion, some had collectives, some have used Thrust Levers where the protocol is still "Up is Up and Down is Down," and some have incorporated both throttles and collectives when designers did not want to deal with the Human Factors issues. There have even been combinations of throttles that incorporated an arc that have been met with varying degrees of success. A previous review was made of nineteen designs without attempting to judge the merits of the controller. Included in this paper are twelve designs entered in competition for the 1961 Tri-Service VTOL transport. Entries were from a Bell/Lockheed tiltduct, a North American tiltwing, a Vanguard liftfan, and even a Sikorsky tiltwing. Additional designs were submitted from Boeing Wichita (direct lift), Ling-Temco-Vought with its XC-142 tiltwing, Boeing Vertol's tiltwing, Mcdonnell's compound and tiltwing, and the Douglas turboduct and turboprop designs. A private party submitted a re-design of the Breguet 941 as a VTOL transport. It is important to document these 53 year-old designs to preserve a part of this country's aviation heritage.

  5. 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.

  6. In-flight acoustic measurements on a light twin-engined turboprop airplane

    NASA Technical Reports Server (NTRS)

    Wilby, J. F.; Mcdaniel, C. D.; Wilby, E. G.

    1985-01-01

    Four series of flight tests were conducted to measure sound pressure levels inside and outside the cabin of a twin-engined turboprop airplane. Particular emphasis was placed on harmonics of the propeller blade passage frequency. The cabin was unfurnished for the first three flights, when the main objective was to investigate the repeatability of the data. For the fourth flight, the cabin was treated with fiberglass batts. Typically, the exterior sound pressure levels were found to vary 3 to 5 dB for a given harmonic, but variations as high as 8 dB were observed. The variability of harmonic levels within the cabin was slightly higher but depended on control of the relative phase between the propellers; when phase was not controlled the average variability was about 10 dB. Noise reductions provided by the fuselage structure were in the range of 20 to 40 dB, when an exterior microphone in the plane of rotation of the propeller was used as reference.

  7. N plus 3 Advanced Concept Studies for Supersonic Commercial Transport Aircraft Entering Service in the 2030-2035 Period

    NASA Technical Reports Server (NTRS)

    Welge, H. Robert; Bonet, John; Magee, Todd; Tompkins, Daniel; Britt, Terry R.; Nelson, Chet; Miller, Gregory; Stenson, Douglas; Staubach, J. Brent; Bala, Naushir; Duge, Robert; OBrien, Mark; Cedoz, Robert; Barlow, Andrew; Martins, Steve; Viars, Phil; Rasheed, Adam; Kirby, Michelle; Raczynski, Chris; Roughen, Kevin; Doyle, Steven; Alston, Katherine; Page, Juliet; Plotkin, Kenneth J.

    2011-01-01

    Boeing, with Pratt & Whitney, General Electric, Rolls-Royce, M4 Engineering, Wyle Laboratories and Georgia Institute of Technology, conducted a study of supersonic commercial aircraft concepts and enabling technologies for the year 2030-2035 timeframe. The work defined the market and environmental/regulatory conditions that could evolve by the 2030/35 time period, from which vehicle performance goals were derived. Relevant vehicle concepts and technologies are identified that are anticipated to meet these performance and environmental goals. A series of multidisciplinary analyses trade studies considering vehicle sizing, mission performance and environmental conformity determined the appropriate concepts. Combinations of enabling technologies and the required technology performance levels needed to meet the desired goals were identified. Several high priority technologies are described in detail, including roadmaps with risk assessments that outline objectives, key technology challenges, detailed tasks and schedules and demonstrations that need to be performed. A representative configuration is provided for reference purposes, along with associated performance estimates based on these key technologies.

  8. Beware of agents when flying aircraft: Basic principles behind a generic methodology for the evaluation and certification of advanced aviation systems

    NASA Technical Reports Server (NTRS)

    Javaux, Denis; Masson, Michel; Dekeyser, Veronique

    1994-01-01

    There is currently a growing interest in the aeronautical community to assess the effects of the increasing levels of automation on pilots' performance and overall safety. The first effect of automation is the change in the nature of the pilot's role on the flight deck. Pilots have become supervisors who monitor aircraft systems in usual situations and intervene only when unanticipated events occur. Instead of 'hand flying' the airplane, pilots contribute to the control of aircraft by acting as mediators, instructions given to the automation. By eliminating the need for manually controlling normal situations, such a role division has reduced the opportunities for the pilot to acquire experience and skills necessary to safely cope with abnormal events. Difficulties in assessing the state and behavior of automation arise mainly from four factors: (1) the complexity of current systems and consequence mode-related problems; (2) the intrinsic autonomy of automation which is able to fire mode transitions without explicit commands from the pilots; (3) the bad quality of feed-back from the control systems displays and interfaces to the pilots; and (4) the fact that the automation currently has no explicit representation of the current pilots' intentions and strategy. Assuming certification has among its major goals to guarantee the passengers' and pilots' safety and the airplane integrity under normal and abnormal operational conditions, the authors suggest it would be particularly fruitful to come up with a conceptual reference system providing the certification authorities both with a theoretical framework and a list of principles usable for assessing the quality of the equipment and designs under examination. This is precisely the scope of this paper. However, the authors recognize that the conceptual presented is still under development and would thus be best considered as a source of reflection for the design, evaluation and certification processes of advanced

  9. Advanced manufacturing development of a composite empennage component for L-1011 aircraft. Phase 4: Full scale ground test

    NASA Technical Reports Server (NTRS)

    Jackson, A. C.; Dorwald, F.

    1982-01-01

    The ground tests conducted on the advanced composite vertical fin (ACVF) program are described. The design and fabrication of the test fixture and the transition structure, static test of Ground Test Article (GTA) No. 1, rework of GTA No. 2, and static, damage tolerance, fail-safe and residual strength tests of GTA No. 2 are described.

  10. A flight-test and simulation evaluation of the longitudinal final approach and landing performance of an automatic system for a light wing loading STOL aircraft equipped with wing spoilers

    NASA Technical Reports Server (NTRS)

    Brown, S. C.; Hardy, G. H.; Hindson, W. S.

    1984-01-01

    As part of a comprehensive flight-test investigation of short takeoff and landing (STOL) operating systems for the terminal systems for the terminal area, an automatic landing system has been developed and evaluated for a light wing-loading turboprop-powered aircraft. An advanced digital avionics system performed display, navigation, guidance, and control functions for the test aircraft. Control signals were generated in order to command powered actuators for all conventional controls and for a set of symmetrically driven wing spoilers. This report describes effects of the spoiler control on longitudinal autoland (automatic landing) performance. Flight-test results, with and without spoiler control, are presented and compared with available (basically, conventional takeoff and landing) performance criteria. These comparisons are augmented by results from a comprehensive simulation of the controlled aircraft that included representations of the microwave landing system navigation errors that were encountered in flight as well as expected variations in atmospheric turbulence and wind shear. Flight-test results show that the addition of spoiler control improves the touchdown performance of the automatic landing system. Spoilers improve longitudinal touchdown and landing pitch-attitude performance, particularly in tailwind conditions. Furthermore, simulation results indicate that performance would probably be satisfactory for a wider range of atmospheric disturbances than those encountered in flight. Flight results also indicate that the addition of spoiler control during the final approach does not result in any measurable change in glidepath track performance, and results in a very small deterioration in airspeed tracking. This difference contrasts with simulations results, which indicate some improvement in glidepath tracking and no appreciable change in airspeed tracking. The modeling problem in the simulation that contributed to this discrepancy with flight was

  11. Start Up Research Effort in Fluid Mechanics. Advanced Methods for Acoustic and Thrust Benefits for Aircraft Engine Nozzle

    NASA Technical Reports Server (NTRS)

    White, Samuel G.; Gilinsky, Mikhail M.

    1997-01-01

    In accordance with the project plan for the report period in the proposal titled above, HU and FML teams investigated two sets of concepts for reduction of noise and improvement in efficiency for jet exhaust nozzles of aircraft engines and screws for mixers, fans, propellers and boats. The main achievements in the report period are: (a) Publication of the paper in the AIAA Journal, which described our concepts and some results. (b) The Award in the Civil Research and Development Foundation (CRDF) competition. This 2 year grant for Hampton University (HU) and Central AeroHydrodynamic Institute (TSAGI, Moscow, Russia) supports the research implementation under the current NASA FAR grant. (c) Selection for funding by NASA HQ review panel of the Partnership Awards Concept Paper. This two year grant also will support our current FAR grant. (d) Publication of a Mobius Strip concept in NASA Technical Briefs, June, 1996, and a great interest of many industrial companies in this invention. Successful experimental results with the Mobius shaped screw for mixers, which save more than 30% of the electric power by comparison with the standard screws. Creation of the scientific-popular video-film which can be used for commercial and educational purposes. (e) Organization work, joint meetings and discussions of the NASA LARC JNL Team and HU professors and administration for the solution of actual problems and effective work of the Fluid Mechanics Laboratory at Hampton University. In this report the main designs are enumerated. It also contains for both concept sets: (1) the statement of the problem for each design, some results, publications, inventions, patents, our vision for continuation of this research, and (2) present and expected problems in the future.

  12. Structural Framework for Flight: NASA's Role in Development of Advanced Composite Materials for Aircraft and Space Structures

    NASA Technical Reports Server (NTRS)

    Tenney, Darrel R.; Davis, John G., Jr.; Johnston, Norman J.; Pipes, R. Byron; McGuire, Jack F.

    2011-01-01

    This serves as a source of collated information on Composite Research over the past four decades at NASA Langley Research Center, and is a key reference for readers wishing to grasp the underlying principles and challenges associated with developing and applying advanced composite materials to new aerospace vehicle concepts. Second, it identifies the major obstacles encountered in developing and applying composites on advanced flight vehicles, as well as lessons learned in overcoming these obstacles. Third, it points out current barriers and challenges to further application of composites on future vehicles. This is extremely valuable for steering research in the future, when new breakthroughs in materials or processing science may eliminate/minimize some of the barriers that have traditionally blocked the expanded application of composite to new structural or revolutionary vehicle concepts. Finally, a review of past work and identification of future challenges will hopefully inspire new research opportunities and development of revolutionary materials and structural concepts to revolutionize future flight vehicles.

  13. An evaluation of methods for scaling aircraft noise perception

    NASA Technical Reports Server (NTRS)

    Ollerhead, J. B.

    1971-01-01

    One hundred and twenty recorded sounds, including jets, turboprops, piston engined aircraft and helicopters were rated by a panel of subjects in a paired comparison test. The results were analyzed to evaluate a number of noise rating procedures in terms of their ability to accurately estimate both relative and absolute perceived noise levels. It was found that the complex procedures developed by Stevens, Zwicker and Kryter are superior to other scales. The main advantage of these methods over the more convenient weighted sound pressure level scales lies in their ability to cope with signals over a wide range of bandwidth. However, Stevens' loudness level scale and the perceived noise level scale both overestimate the growth of perceived level with intensity because of an apparent deficiency in the band level summation rule. A simple correction is proposed which will enable these scales to properly account for the experimental observations.

  14. Aircraft Design

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H. (Inventor); Uden, Edward (Inventor)

    2016-01-01

    The present invention is an aircraft wing design that creates a bell shaped span load, which results in a negative induced drag (induced thrust) on the outer portion of the wing; such a design obviates the need for rudder control of an aircraft.

  15. Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 4: Advanced fan section aerodynamic analysis

    NASA Technical Reports Server (NTRS)

    Crook, Andrew J.; Delaney, Robert A.

    1992-01-01

    The purpose of this study is the development of a three-dimensional Euler/Navier-Stokes flow analysis for fan section/engine geometries containing multiple blade rows and multiple spanwise flow splitters. An existing procedure developed by Dr. J. J. Adamczyk and associates and the NASA Lewis Research Center was modified to accept multiple spanwise splitter geometries and simulate engine core conditions. The procedure was also modified to allow coarse parallelization of the solution algorithm. This document is a final report outlining the development and techniques used in the procedure. The numerical solution is based upon a finite volume technique with a four stage Runge-Kutta time marching procedure. Numerical dissipation is used to gain solution stability but is reduced in viscous dominated flow regions. Local time stepping and implicit residual smoothing are used to increase the rate of convergence. Multiple blade row solutions are based upon the average-passage system of equations. The numerical solutions are performed on an H-type grid system, with meshes being generated by the system (TIGG3D) developed earlier under this contract. The grid generation scheme meets the average-passage requirement of maintaining a common axisymmetric mesh for each blade row grid. The analysis was run on several geometry configurations ranging from one to five blade rows and from one to four radial flow splitters. Pure internal flow solutions were obtained as well as solutions with flow about the cowl/nacelle and various engine core flow conditions. The efficiency of the solution procedure was shown to be the same as the original analysis.

  16. The History of the XV-15 Tilt Rotor Research Aircraft: From Concept to Flight

    NASA Technical Reports Server (NTRS)

    Maisel, Martin D.; Giulianetti, Demo J.; Dugan, Daniel C.

    2000-01-01

    This monograph is a testament to the efforts of many people overcoming multiple technical challenges encountered while developing the XV-15 tilt rotor research aircraft. The Ames involvement with the tilt rotor aircraft began in 1957 with investigations of the performance and dynamic behavior of the Bell XV-3 tilt rotor aircraft. At that time, Ames Research Center was known as the Ames Aeronautical Laboratory of the National Advisory Committee for Aeronautics (NACA). As we approach the new millennium, and after more than 40 years of effort and the successful completion of our initial goals, it is appropriate to reflect on the technical accomplishments and consider the future applications of this unique aircraft class, the tilt rotor. The talented engineers, technicians, managers, and leaders at Ames have worked hard with their counterparts in the U.S. rotorcraft industry to overcome technology barriers and to make the military and civil tilt rotor aircraft safer, environmentally acceptable, and more efficient. The tilt rotor aircraft combines the advantages of vertical takeoff and landing capabilities, inherent to the helicopter, with the forward speed and range of a fixed wing turboprop airplane. Our studies have shown that this new vehicle type can provide the aviation transportation industry with the flexibility for highspeed, long-range flight, coupled with runway-independent operations, thus having a significant potential to relieve airport congestion. We see the tilt rotor aircraft as an element of the solution to this growing air transport problem.

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

    NASA Astrophysics Data System (ADS)

    Kong, Changduk; Lim, Semyeong

    2011-12-01

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

  18. Transport aircraft accident dynamics

    NASA Technical Reports Server (NTRS)

    Cominsky, A.

    1982-01-01

    A study was carried out of 112 impact survivable jet transport aircraft accidents (world wide) of 27,700 kg (60,000 lb.) aircraft and up extending over the last 20 years. This study centered on the effect of impact and the follow-on events on aircraft structures and was confined to the approach, landing and takeoff segments of the flight. The significant characteristics, frequency of occurrence and the effect on the occupants of the above data base were studied and categorized with a view to establishing typical impact scenarios for use as a basis of verifying the effectiveness of potential safety concepts. Studies were also carried out of related subjects such as: (1) assessment of advanced materials; (2) human tolerance to impact; (3) merit functions for safety concepts; and (4) impact analysis and test methods.

  19. Advanced manufacturing development of a composite empennage component for L-1011 aircraft. Phase 3: Production readiness verification testing

    NASA Technical Reports Server (NTRS)

    Jackson, A.; Sandifer, J.; Sandorff, P.; Vancleave, R.

    1984-01-01

    Twenty-two specimens of each of two key structural elements of the Advance Composite Vertical Fin (ACVF) were fabricated and tested. One element represented the front spar at the fuselage attachment area and the other element represented the cover at the fuselage joint area. Ten specimens of each element were selected for static testing. The coefficient of variation resulting from the tests was 3.28 percent for the ten cover specimens and 6.11 percent for the ten spar specimens, which compare well with metallic structures. The remaining twelve cover and twelve spar specimens were durability tested in environmental chambers which permitted the temperature and humidity environment to be cycled as well as the applied loads. Results of the durability tests indicated that such components will survive the service environment.

  20. Propulsion/ACEE

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The research objectives of the NASA aircraft energy efficiency program are summarized. Engine component improvements for turbofan engines, diagnostics, the development of advanced turboprop engines, and propeller noise analysis are discussed.

  1. Hydrogen Storage for Aircraft Applications Overview

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.; Kohout, Lisa (Technical Monitor)

    2002-01-01

    Advances in fuel cell technology have brought about their consideration as sources of power for aircraft. This power can be utilized to run aircraft systems or even provide propulsion power. One of the key obstacles to utilizing fuel cells on aircraft is the storage of hydrogen. An overview of the potential methods of hydrogen storage was compiled. This overview identifies various methods of hydrogen storage and points out their advantages and disadvantages relative to aircraft applications. Minimizing weight and volume are the key aspects to storing hydrogen within an aircraft. An analysis was performed to show how changes in certain parameters of a given storage system affect its mass and volume.

  2. Perspectives on Highly Adaptive or Morphing Aircraft

    NASA Technical Reports Server (NTRS)

    McGowan, Anna-Maria R.; Vicroy, Dan D.; Busan, Ronald C.; Hahn, Andrew S.

    2009-01-01

    The ability to adapt to different flight conditions has been fundamental to aircraft design since the Wright Brothers first flight. Over a hundred years later, unconventional aircraft adaptability, often called aircraft morphing has become a topic of considerable renewed interest. In the past two decades, this interest has been largely fuelled by advancements in multi-functional or smart materials and structures. However, highly adaptive or morphing aircraft is certainly a cross-discipline challenge that stimulates a wide range of design possibilities. This paper will review some of the history of morphing aircraft including recent research programs and discuss some perspectives on this work.

  3. Aircraft engine pollution reduction.

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1972-01-01

    The effect of engine operation on the types and levels of the major aircraft engine pollutants is described and the major factors governing the formation of these pollutants during the burning of hydrocarbon fuel are discussed. Methods which are being explored to reduce these pollutants are discussed and their application to several experimental research programs are pointed out. Results showing significant reductions in the levels of carbon monoxide, unburned hydrocarbons, and oxides of nitrogen obtained from experimental combustion research programs are presented and discussed to point out potential application to aircraft engines. An experimental program designed to develop and demonstrate these and other advanced, low pollution combustor design methods is described. Results that have been obtained to date indicate considerable promise for reducing advanced engine exhaust pollutants to levels significantly below current engines.

  4. Commercial transport aircraft composite structures

    NASA Technical Reports Server (NTRS)

    Mccarty, J. E.

    1983-01-01

    The role that analysis plays in the development, production, and substantiation of aircraft structures is discussed. The types, elements, and applications of failure that are used and needed; the current application of analysis methods to commercial aircraft advanced composite structures, along with a projection of future needs; and some personal thoughts on analysis development goals and the elements of an approach to analysis development are discussed.

  5. Langley Aircraft Landing Dynamics Facility

    NASA Technical Reports Server (NTRS)

    Davis, Pamela A.; Stubbs, Sandy M.; Tanner, John A.

    1987-01-01

    The Langley Research Center has recently upgraded the Landing Loads Track (LLT) to improve the capability of low-cost testing of conventional and advanced landing gear systems. The unique feature of the Langley Aircraft Landing Dynamics Facility (ALDF) is the ability to test aircraft landing gear systems on actual runway surfaces at operational ground speeds and loading conditions. A historical overview of the original LLT is given, followed by a detailed description of the new ALDF systems and operational capabilities.

  6. Economic impact of fuel properties on turbine powered business aircraft

    NASA Technical Reports Server (NTRS)

    Powell, F. D.

    1984-01-01

    The principal objective was to estimate the economic impact on the turbine-powered business aviation fleet of potential changes in the composition and properties of aviation fuel. Secondary objectives include estimation of the sensitivity of costs to specific fuel properties, and an assessment of the directions in which further research should be directed. The study was based on the published characteristics of typical and specific modern aircraft in three classes; heavy jet, light jet, and turboprop. Missions of these aircraft were simulated by computer methods for each aircraft for several range and payload combinations, and assumed atmospheric temperatures ranging from nominal to extremely cold. Five fuels were selected for comparison with the reference fuel, nominal Jet A. An overview of the data, the mathematic models, the data reduction and analysis procedure, and the results of the study are given. The direct operating costs of the study fuels are compared with that of the reference fuel in the 1990 time-frame, and the anticipated fleet costs and fuel break-even costs are estimated.

  7. Robots for Aircraft Maintenance

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Marshall Space Flight Center charged USBI (now Pratt & Whitney) with the task of developing an advanced stripping system based on hydroblasting to strip paint and thermal protection material from Space Shuttle solid rocket boosters. A robot, mounted on a transportable platform, controls the waterjet angle, water pressure and flow rate. This technology, now known as ARMS, has found commercial applications in the removal of coatings from jet engine components. The system is significantly faster than manual procedures and uses only minimal labor. Because the amount of "substrate" lost is minimal, the life of the component is extended. The need for toxic chemicals is reduced, as is waste disposal and human protection equipment. Users of the ARMS work cell include Delta Air Lines and the Air Force, which later contracted with USBI for development of a Large Aircraft Paint Stripping system (LARPS). LARPS' advantages are similar to ARMS, and it has enormous potential in military and civil aircraft maintenance. The technology may also be adapted to aircraft painting, aircraft inspection techniques and paint stripping of large objects like ships and railcars.

  8. 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.

  9. Aircraft cybernetics

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The use of computers for aircraft control, flight simulation, and inertial navigation is explored. The man-machine relation problem in aviation is addressed. Simple and self-adapting autopilots are described and the assets and liabilities of digital navigation techniques are assessed.

  10. Project report: Aircraft

    SciTech Connect

    Wuebbles, D.J.; Baughcum, S.; Metwally, M.; Seals, R.

    1994-04-01

    Analyses of scenarios of past and possible future emissions are an important aspect of assessing the potential environmental effects from aircraft, including the proposed high speed civil transport (HSCT). The development of a detailed three-dimensional database that accurately represents the integration of all aircraft emissions along realistic flight paths for such scenarios requires complex computational modeling capabilities. Such a detailed data set is required for the scenarios evaluated in this interim assessment. Within the NASA High-Speed Research Program, the Emissions Scenarios Committee provides a forum for identifying the required scenarios and evaluating the resulting database being developed with the advanced emissions modeling capabilities at the Boeing Company and McDonnell Douglas Corporation.

  11. An assessment of the benefits of the use of NASA developed fuel conservative technology in the US commercial aircraft fleet

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Cost and benefits of a fuel conservative aircraft technology program proposed by NASA are estimated. NASA defined six separate technology elements for the proposed program: (a) engine component improvement (b) composite structures (c) turboprops (d) laminar flow control (e) fuel conservative engine and (f) fuel conservative transport. There were two levels postulated: The baseline program was estimated to cost $490 million over 10 years with peak funding in 1980. The level two program was estimated to cost an additional $180 million also over 10 years. Discussions with NASA and with representatives of the major commercial airframe manufacturers were held to estimate the combinations of the technology elements most likely to be implemented, the potential fuel savings from each combination, and reasonable dates for incorporation of these new aircraft into the fleet.

  12. The F-18 systems research aircraft facility

    NASA Technical Reports Server (NTRS)

    Sitz, Joel R.

    1992-01-01

    To help ensure that new aerospace initiatives rapidly transition to competitive U.S. technologies, NASA Dryden Flight Research Facility has dedicated a systems research aircraft facility. The primary goal is to accelerate the transition of new aerospace technologies to commercial, military, and space vehicles. Key technologies include more-electric aircraft concepts, fly-by-light systems, flush airdata systems, and advanced computer architectures. Future aircraft that will benefit are the high-speed civil transport and the National AeroSpace Plane. This paper describes the systems research aircraft flight research vehicle and outlines near-term programs.

  13. Unified aeroacoustics analysis for high speed turboprop aerodynamics and noise. Volume 3: Application of theory for blade loading, wakes, noise, and wing shielding

    NASA Technical Reports Server (NTRS)

    Hanson, D. B.; Mccolgan, C. J.; Ladden, R. M.; Klatte, R. J.

    1991-01-01

    Results of the program for the generation of a computer prediction code for noise of advanced single rotation, turboprops (prop-fans) such as the SR3 model are presented. The code is based on a linearized theory developed at Hamilton Standard in which aerodynamics and acoustics are treated as a unified process. Both steady and unsteady blade loading are treated. Capabilities include prediction of steady airload distributions and associated aerodynamic performance, unsteady blade pressure response to gust interaction or blade vibration, noise fields associated with thickness and steady and unsteady loading, and wake velocity fields associated with steady loading. The code was developed on the Hamilton Standard IBM computer and has now been installed on the Cray XMP at NASA-Lewis. The work had its genesis in the frequency domain acoustic theory developed at Hamilton Standard in the late 1970s. It was found that the method used for near field noise predictions could be adapted as a lifting surface theory for aerodynamic work via the pressure potential technique that was used for both wings and ducted turbomachinery. In the first realization of the theory for propellers, the blade loading was represented in a quasi-vortex lattice form. This was upgraded to true lifting surface loading. Originally, it was believed that a purely linear approach for both aerodynamics and noise would be adequate. However, two sources of nonlinearity in the steady aerodynamics became apparent and were found to be a significant factor at takeoff conditions. The first is related to the fact that the steady axial induced velocity may be of the same order of magnitude as the flight speed and the second is the formation of leading edge vortices which increases lift and redistribute loading. Discovery and properties of prop-fan leading edge vortices were reported in two papers. The Unified AeroAcoustic Program (UAAP) capabilites are demonstrated and the theory verified by comparison with the

  14. Full-scale testing, production and cost analysis data for the advanced composite stabilizer for Boeing 737 aircraft. Volume 1: Technical summary

    NASA Technical Reports Server (NTRS)

    Aniversario, R. B.; Harvey, S. T.; Mccarty, J. E.; Parsons, J. T.; Peterson, D. C.; Pritchett, L. D.; Wilson, D. R.; Wogulis, E. R.

    1983-01-01

    The full scale ground test, ground vibration test, and flight tests conducted to demonstrate a composite structure stabilizer for the Boeing 737 aircraft and obtain FAA certification are described. Detail tools, assembly tools, and overall production are discussed. Cost analyses aspects covered include production costs, composite material usage factors, and cost comparisons.

  15. Advanced risk assessment of the effects of graphite fibers on electronic and electric equipment, phase 1. [simulating vulnerability to airports and communities from fibers released during aircraft fires

    NASA Technical Reports Server (NTRS)

    Pocinki, L. S.; Kaplan, L. D.; Cornell, M. E.; Greenstone, R.

    1979-01-01

    A model was developed to generate quantitative estimates of the risk associated with the release of graphite fibers during fires involving commercial aircraft constructed with graphite fiber composite materials. The model was used to estimate the risk associated with accidents at several U.S. airports. These results were then combined to provide an estimate of the total risk to the nation.

  16. Emerging nondestructive inspection methods for aging aircraft

    SciTech Connect

    Beattie, A; Dahlke, L; Gieske, J

    1994-01-01

    This report identifies and describes emerging nondestructive inspection (NDI) methods that can potentially be used to inspect commercial transport and commuter aircraft for structural damage. The nine categories of emerging NDI techniques are: acoustic emission, x-ray computed tomography, backscatter radiation, reverse geometry x-ray, advanced electromagnetics, including magnetooptic imaging and advanced eddy current techniques, coherent optics, advanced ultrasonics, advanced visual, and infrared thermography. The physical principles, generalized performance characteristics, and typical applications associated with each method are described. In addition, aircraft inspection applications are discussed along with the associated technical considerations. Finally, the status of each technique is presented, with a discussion on when it may be available for use in actual aircraft maintenance programs. It should be noted that this is a companion document to DOT/FAA/CT-91/5, Current Nondestructive Inspection Methods for Aging Aircraft.

  17. Composite structural materials. [aircraft applications

    NASA Technical Reports Server (NTRS)

    Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

    1981-01-01

    The development of composite materials for aircraft applications is addressed with specific consideration of physical properties, structural concepts and analysis, manufacturing, reliability, and life prediction. The design and flight testing of composite ultralight gliders is documented. Advances in computer aided design and methods for nondestructive testing are also discussed.

  18. Flight testing of unique aircraft configurations

    NASA Technical Reports Server (NTRS)

    Painter, W. D.

    1983-01-01

    Some historical developments of flight testing of unique aircraft configurations by NASA and the military sector are documented. Several test aircraft are outlined including the M2-F1 (which was the first Space Shuttle concept ever demonstrated, and contributed to the present design), the X-15, the Flying Wing, the Lunar Landing Research Vehicle, the Oblique Wing Research Aircraft, and the Space Shuttle Enterprise. Future test aircraft such as the forward swept wing X-29A Advanced Technology Demonstrator Aircraft, and the X-Wing vehicle are also mentioned. It is noted that the logical preliminary to flight testing is flight simulation, and that flight testing itself is the vital final component of the development, and seems to be the most direct approach to aircraft evaluations.

  19. Flight test techniques for the X-29A aircraft

    NASA Technical Reports Server (NTRS)

    Hicks, John W.; Cooper, James M., Jr.; Sefic, Walter J.

    1987-01-01

    The X-29A advanced technology demonstrator is a single-seat, single-engine aircraft with a forward-swept wing. The aircraft incorporates many advanced technologies being considered for this country's next generation of aircraft. This unusual aircraft configuration, which had never been flown before, required a precise approach to flight envelope expansion. This paper describes the real-time analysis methods and flight test techniques used during the envelope expansion of the x-29A aircraft, including new and innovative approaches.

  20. Technologies for Aircraft Noise Reduction

    NASA Technical Reports Server (NTRS)

    Huff, Dennis L.

    2006-01-01

    Technologies for aircraft noise reduction have been developed by NASA over the past 15 years through the Advanced Subsonic Technology (AST) Noise Reduction Program and the Quiet Aircraft Technology (QAT) project. This presentation summarizes highlights from these programs and anticipated noise reduction benefits for communities surrounding airports. Historical progress in noise reduction and technologies available for future aircraft/engine development are identified. Technologies address aircraft/engine components including fans, exhaust nozzles, landing gear, and flap systems. New "chevron" nozzles have been developed and implemented on several aircraft in production today that provide significant jet noise reduction. New engines using Ultra-High Bypass (UHB) ratios are projected to provide about 10 EPNdB (Effective Perceived Noise Level in decibels) engine noise reduction relative to the average fleet that was flying in 1997. Audio files are embedded in the presentation that estimate the sound levels for a 35,000 pound thrust engine for takeoff and approach power conditions. The predictions are based on actual model scale data that was obtained by NASA. Finally, conceptual pictures are shown that look toward future aircraft/propulsion systems that might be used to obtain further noise reduction.

  1. Dual-Mission Large Aircraft Feasibility Study and Aerodynamic Investigation

    NASA Technical Reports Server (NTRS)

    Mavris, Dimitri

    1997-01-01

    A Dual-Mission Large Aircraft, or DMLA, represents the possibility of a single aircraft capable of fulfilling both a Global Reach Aircraft (GRA) and Very Large Transport (VLT) roles. The DMLA, by combining the GRA and VLT into a single new aircraft, could possibly lower the aircraft manufacturer's production costs through the resulting increase in production quantity. This translates into lower aircraft acquisition costs, a primary concern for both the Air Force and commercial airlines. This report outlines the first steps taken in this study, namely the assessment of technical and economic feasibility of the DMLA concept. In the course of this project, specialized GRA and VLT aircraft were sized for their respective missions, using baseline conventional (i.e., lacking advanced enabling technologies) aircraft models from previous work for the Air Force's Wright Laboratory and NASA-Langley. DMLA baseline aircraft were then also developed, by first sizing the aircraft for the more critical of the two missions and then analyzing the aircraft's performance over the other mission. The resulting aircraft performance values were then compared to assess technical feasibility. Finally, the life-cycle costs of each aircraft (GRA, VLT, and DMLA) were analyzed to quantify economic feasibility. These steps were applied to both a two-engine aircraft set, and a four-engine aircraft set.

  2. Educating with Aircraft Models

    ERIC Educational Resources Information Center

    Steele, Hobie

    1976-01-01

    Described is utilization of aircraft models, model aircraft clubs, and model aircraft magazines to promote student interest in aerospace education. The addresses for clubs and magazines are included. (SL)

  3. Investigation of Advanced Counterrotation Blade Configuration Concepts for High Speed Turboprop Systems. Task 8: Cooling Flow/heat Transfer Analysis

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Topp, David A.; Heidegger, Nathan J.; Delaney, Robert A.

    1994-01-01

    The focus of this task was to validate the ADPAC code for heat transfer calculations. To accomplish this goal, the ADPAC code was modified to allow for a Cartesian coordinate system capability and to add boundary conditions to handle spanwise periodicity and transpiration boundaries. The primary validation case was the film cooled C3X vane. The cooling hole modeling included both a porous region and grid in each discrete hold. Predictions for these models as well as smooth wall compared well with the experimental data.

  4. Alternative general-aircraft engines

    NASA Technical Reports Server (NTRS)

    Tomazic, W. A.

    1976-01-01

    The most promising alternative engine (or engines) for application to general aircraft in the post-1985 time period was defined, and the level of technology was cited to the point where confident development of a new engine can begin early in the 1980's. Low emissions, multifuel capability, and fuel economy were emphasized. Six alternative propulsion concepts were considered to be viable candidates for future general-aircraft application: the advanced spark-ignition piston, rotary combustion, two- and four-stroke diesel, Stirling, and gas turbine engines.

  5. Aircraft radar antennas

    NASA Astrophysics Data System (ADS)

    Schrank, Helmut E.

    1987-04-01

    Many changes have taken place in airborne radar antennas since their beginnings over forty years ago. A brief historical review of the advances in technology is presented, from mechanically scanned reflectors to modern multiple function phased arrays. However, emphasis is not on history but on the state-of-the-art technology and trends for future airborne radar systems. The status of rotating surveillance antennas is illustrated by the AN/APY-1 Airborne Warning and Control System (AWACS) slotted waveguide array, which achieved a significant breakthrough in sidelobe suppression. Gimballed flat plate arrays in nose radomes are typified by the AN/APG-66 (F-16) antenna. Multifunction phased arrays are presented by the Electronically Agile Radar (EAR) antenna, which has achieved significant advances in performance versatility and reliability. Trends toward active aperture, adaptive, and digital beamforming arrays are briefly discussed. Antennas for future aircraft radar systems must provide multiple functions in less aperture space, and must perform more reliably.

  6. A review of NASA's propulsion programs for aviation

    NASA Technical Reports Server (NTRS)

    Stewart, W. L.; Johnson, H. W.; Weber, R. J.

    1978-01-01

    A review of five NASA engine-oriented propulsion programs of major importance to civil aviation are presented and discussed. Included are programs directed at exploring propulsion system concepts for (1) energy conservation subsonic aircraft (improved current turbofans, advanced turbofans, and advanced turboprops); (2) supersonic cruise aircraft (variable cycle engines); (3) general aviation aircraft (improved reciprocating engines and small gas turbines); (4) powered lift aircraft (advanced turbofans); and (5) advanced rotorcraft.

  7. Large-scale Advanced Propfan (LAP) performance, acoustic and weight estimation, January, 1984

    NASA Technical Reports Server (NTRS)

    Parzych, D.; Shenkman, A.; Cohen, S.

    1985-01-01

    In comparison to turbo-prop applications, the Prop-Fan is designed to operate in a significantly higher range of aircraft flight speeds. Two concerns arise regarding operation at very high speeds: aerodynamic performance and noise generation. This data package covers both topics over a broad range of operating conditions for the eight (8) bladed SR-7L Prop-Fan. Operating conditions covered are: Flight Mach Number 0 - 0.85; blade tip speed 600-800 ft/sec; and cruise power loading 20-40 SHP/D2. Prop-Fan weight and weight scaling estimates are also included.

  8. Study on Practical Application of Turboprop Engine Condition Monitoring and Fault Diagnostic System Using Fuzzy-Neuro Algorithms

    NASA Astrophysics Data System (ADS)

    Kong, Changduk; Lim, Semyeong; Kim, Keunwoo

    2013-03-01

    The Neural Networks is mostly used to engine fault diagnostic system due to its good learning performance, but it has a drawback due to low accuracy and long learning time to build learning data base. This work builds inversely a base performance model of a turboprop engine to be used for a high altitude operation UAV using measuring performance data, and proposes a fault diagnostic system using the base performance model and artificial intelligent methods such as Fuzzy and Neural Networks. Each real engine performance model, which is named as the base performance model that can simulate a new engine performance, is inversely made using its performance test data. Therefore the condition monitoring of each engine can be more precisely carried out through comparison with measuring performance data. The proposed diagnostic system identifies firstly the faulted components using Fuzzy Logic, and then quantifies faults of the identified components using Neural Networks leaned by fault learning data base obtained from the developed base performance model. In leaning the measuring performance data of the faulted components, the FFBP (Feed Forward Back Propagation) is used. In order to user's friendly purpose, the proposed diagnostic program is coded by the GUI type using MATLAB.

  9. Commercial aircraft fuel efficiency potential through 2010

    SciTech Connect

    Greene, D.L.

    1990-01-01

    Aircraft are second only to motor vehicles in the use of motor fuels, and air travel is growing twice as fast. Since 1970 air travel has more than tripled, but the growth of fuel use has been restrained by a near doubling of efficiency, from 26.2 seat miles per gallon (SMPG) in 1970 to about 49 SMPG in 1989. This paper explores the potential for future efficiency improvements via the replacement of existing aircraft with 1990's generation'' and post 2000'' aircraft incorporating advances in engine and airframe technology. Today, new commercial passenger aircraft deliver 50--70 SMPG. New aircraft types scheduled for delivery in the early 1990's are expected to achieve 65--80 SMPG. Industry and government researchers have identified technologies capable of boosting aircraft efficiencies to the 100--150 SMPG range. Under current industry plans, which do not include a post-2000 generation of new aircraft, the total aircraft fleet should reach the vicinity of 65 SMPG by 2010. A new generation of 100--150 SMPG aircraft introduced in 2005 could raise the fleet average efficiency to 75--80 SMPG in 2010. In any case, fuel use will likely continue to grow at from 1--2%/yr. through 2010. 20 refs., 2 figs., 2 tabs.

  10. Innovative materials for aircraft morphing

    NASA Astrophysics Data System (ADS)

    Simpson, Joycelyn O.; Wise, Stephanie A.; Bryant, R. G.; Cano, R. J.; Gates, T. S.; Hinkley, J. A.; Rogowski, Robert S.; Whitley, K. S.

    1998-06-01

    Reported herein is an overview of the research being conducted within the materials division at NASA Langley Research Center on the development of smart material technologies for advanced airframe systems. The research is a part of the Aircraft Morphing Program which is a new six- year research program to develop smart components for self- adaptive airframe systems. The fundamental areas of materials research within the program are computational materials; advanced piezoelectric materials; advanced fiber optic sensing techniques; and fabrication of integrated composite structures. This paper presents a portion of the ongoing research in each of these areas of materials research.

  11. Innovative Materials for Aircraft Morphing

    NASA Technical Reports Server (NTRS)

    Simpson, J. O.; Wise, S. A.; Bryant, R. G.; Cano, R. J.; Gates, T. S.; Hinkley, J. A.; Rogowski, R. S.; Whitley, K. S.

    1997-01-01

    Reported herein is an overview of the research being conducted within the Materials Division at NASA Langley Research Center on the development of smart material technologies for advanced airframe systems. The research is a part of the Aircraft Morphing Program which is a new six-year research program to develop smart components for self-adaptive airframe systems. The fundamental areas of materials research within the program are computational materials; advanced piezoelectric materials; advanced fiber optic sensing techniques; and fabrication of integrated composite structures. This paper presents a portion of the ongoing research in each of these areas of materials research.

  12. Aircraft Electric Secondary Power

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Technologies resulted to aircraft power systems and aircraft in which all secondary power is supplied electrically are discussed. A high-voltage dc power generating system for fighter aircraft, permanent magnet motors and generators for aircraft, lightweight transformers, and the installation of electric generators on turbine engines are among the topics discussed.

  13. Compilation of energy efficient concepts in advanced aircraft design and operations. Volume II. Abstract Data Base. Final report, 10 March-5 November 1980

    SciTech Connect

    Clyman, M.; Einhorn, S.J.; Shultz, R.S.

    1980-11-05

    Volume II contains the ACE Data Base arranged into eleven areas of RandD effort as follows: Fuels--Synthetic, Liquid Hydrogen, Other; Propulsion--Gas Turbine, Nuclear, Advanced; Aerodynamics; Structures and Materials; Flight Performance Management; Advanced and Unconventional Systems; and Energy Efficient Operation.

  14. Payload Technologies For Remotely Piloted Aircraft

    NASA Technical Reports Server (NTRS)

    Wegener, Steve; Condon, Estelle (Technical Monitor)

    2001-01-01

    Matching the capabilities of Remotely Piloted Aircraft (RPA) to the needs of users defines the direction of future investment. These user needs and advances in payload capabilities are driving the evolution of a commercially viable RPA aerospace industry. New perspectives are needed to realize the potential of RPAs. Advances in payload technologies and the impact on RPA design and operations will be explored.

  15. Payload Technologies for Remotely Piloted Aircraft

    NASA Technical Reports Server (NTRS)

    Wegener, Steve

    2000-01-01

    Matching the capabilities of Remotely Piloted Aircraft (RPA) to the needs of users defines the direction of future investment. These user needs and advances in payload capabilities are driving the evolution of a commercially viable RPA aerospace industry. New perspectives are needed to realize the potential of RPAs. Advances in payload technologies and the impact on RPA design and operations will be explored.

  16. Very Light Aircraft: Revitalization through Certification

    NASA Technical Reports Server (NTRS)

    Zyskowski, Michael K.

    1995-01-01

    As the future of the general aviation industry seems to be improving, a cultural paradigm shift may be imminent with the implementation of an advanced, revolutionary transportation system within the United States. By observing the support of government and industry for this idea, near and long term effects must be addressed if this change is going to occur. The high certification costs associated with general aviation aircraft must be reduced without compromising safety if a new transportation system is to be developed in the future. With the advent of new, streamlined rules recently issued for the certification of small aircraft, it seems as though new opportunities are now available to the general aviation industry. Not only will immediate benefits be realized with increased sales of certified small aircraft, but there would now be a way of introducing the advanced concepts of future aircraft at varying degrees of technology and cost as options to the customer.

  17. Compilation of energy efficient concepts in advanced aircraft design and operations. Volume 2: abstract data base. Interim; Final Report, 10 March - 5 November 1980

    SciTech Connect

    Clyman, M.; Einhorn, S.J.; Schultz, R.S.

    1980-11-01

    The technologies necessary to support next generation (I 1990+) air vehicle design and operation concepts that will reduce the requirements for natural petroleum derived energy are considered in the Advanced Concepts Data Base which consists of 599 abstracts listed as 948 entries. The data base abstracts are arranged into 11 areas of R D effort as follows: synthetic fuels, liquid hydrogen fuels, other fuels gas turbines, nuclear propulsion, advanced propulsion aerodynamics structures and materials flight performance management advanced and unconventional systems and energy efficient operation.

  18. PAN AIR analysis of the NASA/MCAIR 279-3: An advanced supersonic V/STOL fighter/attack aircraft

    NASA Technical Reports Server (NTRS)

    Madson, Michael D.; Erickson, Larry L.

    1986-01-01

    PAN AIR is a computer program for predicting subsonic or supersonic linear potential flow about arbitrary configurations. The program was applied to a highly complex single-engine-cruise V/STOL fighter/attack aircraft. Complexities include a close-coupled canard/wing, large inlets, and four exhaust nozzles mounted directly under the wing and against the fuselage. Modeling uncertainties involving canard wake location and flow-through approximation through the inlet and the exhaust nozzles were investigated. The recently added streamline capability of the program was utilized to evaluate visually the predicted flow over the model. PAN AIR results for Mach numbers of 0.6, 0.9, and angles of attack of 0, 5, and 10 deg. were compared with data obtained in the Ames 11- by 11-Foot Transonic Wind tunnel, at a Reynolds number of 3.69 x 10 to the 6th power based on c bar.

  19. The NASA/industry Design Analysis Methods for Vibrations (DAMVIBS) program: Sikorsky Aircraft: Advances toward interacting with the airframe design process

    NASA Technical Reports Server (NTRS)

    Twomey, William J.

    1993-01-01

    A short history is traced of the work done at Sikorsky Aircraft under the NASA/industry DAMVIBS program. This includes both work directly funded by the program as well as work which was internally funded but which received its initial impetus from DAMVIBS. The development of a finite element model of the UH-60A airframe having a marked improvement in vibration-predicting ability is described. A new program, PAREDYM, developed at Sikorsky, which automatically adjusts an FEM so that its modal characteristics match test values, is described, as well as the part this program played in the improvement of the UH-60A model. Effects of the bungee suspension system on the shake test data used for model verification are described. The impetus given by the modeling improvement, as well as the recent availability of PAREDYM, has brought for the first time the introduction of low-vibration design into the design cycle at Sikorsky.

  20. In flight measurement of steady and unsteady blade surface pressure of a single rotation large scale advanced prop-fan installed on the PTA aircraft

    NASA Technical Reports Server (NTRS)

    Parzych, D.; Boyd, L.; Meissner, W.; Wyrostek, A.

    1991-01-01

    An experiment was performed by Hamilton Standard, Division of United Technologies Corporation, under contract by LeRC, to measure the blade surface pressure of a large scale, 8 blade model prop-fan in flight. The test bed was the Gulfstream 2 Prop-Fan Test Assessment (PTA) aircraft. The objective of the test was to measure the steady and periodic blade surface pressure resulting from three different Prop-Fan air inflow angles at various takeoff and cruise conditions. The inflow angles were obtained by varying the nacelle tilt angles, which ranged from -3 to +2 degrees. A range of power loadings, tip speeds, and altitudes were tested at each nacelle tilt angle over the flight Mach number range of 0.30 to 0.80. Unsteady blade pressure data tabulated as Fourier coefficients for the first 35 harmonics of shaft rotational frequency and the steady (non-varying) pressure component are presented.

  1. High speed turboprop aeroacoustic study (single rotation). Volume 1: Model development

    NASA Technical Reports Server (NTRS)

    Whitfield, C. E.; Gliebe, P. R.; Mani, R.; Mungur, P.

    1989-01-01

    A frequency-domain noncompact-source theory for the steady loading and volume-displacement (thickness) noise of high speed propellers has been developed and programmed. Both near field and far field effects have been considered. The code utilizes blade surface pressure distributions obtained from three-dimensional nonlinear aerodynamic flow field analysis programs as input for evaluating the steady loading noise. Simplified mathematical models of the velocity fields induced at the propeller disk by nearby wing and fuselage surfaces and by angle-of-attack operation have been developed to provide estimates of the unsteady loading imposed on the propeller by these potential field type interactions. These unsteady blade loadings have been coupled to a chordwise compact propeller unsteady loading noise model to provide predictions of unsteady loading noise caused by these installation effects. Finally, an analysis to estimate the corrections to be applied to the free-field noise predictions in order to arrive at the measurable fuselage sound pressure levels has been formulated and programmed. This analysis considers the effects of fuselage surface reflection and diffraction together with surface boundary layer refraction. The steady loading and thickness model and the unsteady loading model have been verified using NASA-supplied data for the SR-2 and SR-3 model propfans. In addition, the steady loading and thickness model has been compared with data from the SR-6 model propfan. These theoretical models have been employed in the evaluation of the SR-7 powered Gulfstream aircraft in terms of noise characteristics at representative takeoff, cruise, and approach operating conditions. In all cases, agreement between theory and experiment is encouraging.

  2. Multidisciplinary Techniques and Novel Aircraft Control Systems

    NASA Technical Reports Server (NTRS)

    Padula, Sharon L.; Rogers, James L.; Raney, David L.

    2000-01-01

    The Aircraft Morphing Program at NASA Langley Research Center explores opportunities to improve airframe designs with smart technologies. Two elements of this basic research program are multidisciplinary design optimization (MDO) and advanced flow control. This paper describes examples where MDO techniques such as sensitivity analysis, automatic differentiation, and genetic algorithms contribute to the design of novel control systems. In the test case, the design and use of distributed shapechange devices to provide low-rate maneuvering capability for a tailless aircraft is considered. The ability of MDO to add value to control system development is illustrated using results from several years of research funded by the Aircraft Morphing Program.

  3. Research needs in aircraft noise prediction

    NASA Technical Reports Server (NTRS)

    Raney, J. P.

    1975-01-01

    Progress needed in understanding the mechanisms of aircraft noise generation and propagation is outlined using the focus provided by the need to predict accurately the noise produced and received at the ground by an aircraft operating in the vicinity of an airport. The components of internal engine noise generation, jet exhaust, airframe noise and shielding and configuration effects, and the roles of atmospheric propagation and ground noise attenuation are presented and related to the prediction problem. The role of NASA in providing the focus and direction for needed advances is discussed, and possible contributions of the academic community in helping to fulfill the needs for accurate aircraft noise prediction methods are suggested.

  4. Systems integration studies for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Mascitti, V. R.

    1975-01-01

    Technical progress in each of the disciplinary research areas affecting the design of supersonic cruise aircraft is discussed. The NASA AST/SCAR Program supported the integration of these technical advances into supersonic cruise aircraft configuration concepts. While the baseline concepts reflect differing design philosophy, all reflect a level of economic performance considerably above the current foreign aircraft as well as the former U.S. SST. Range-payload characteristics of the study configurating show significant improvement, while meeting environmental goals such as takeoff and landing noise and upper atmospheric pollution.

  5. Overview of Innovative Aircraft Power and Propulsion Systems and Their Applications for Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony; Landis, Geoffrey; Lyons, Valerie

    2003-01-01

    Planetary exploration may be enhanced by the use of aircraft for mobility. This paper reviews the development of aircraft for planetary exploration missions at NASA and reviews the power and propulsion options for planetary aircraft. Several advanced concepts for aircraft exploration, including the use of in situ resources, the possibility of a flexible all-solid-state aircraft, the use of entomopters on Mars, and the possibility of aerostat exploration of Titan, are presented.

  6. The NASA aircraft icing research program

    NASA Technical Reports Server (NTRS)

    Shaw, Robert J.; Reinmann, John J.

    1990-01-01

    The objective of the NASA aircraft icing research program is to develop and make available to industry icing technology to support the needs and requirements for all-weather aircraft designs. Research is being done for both fixed wing and rotary wing applications. The NASA program emphasizes technology development in two areas, advanced ice protection concepts and icing simulation. Reviewed here are the computer code development/validation, icing wind tunnel testing, and icing flight testing efforts.

  7. Propulsion controlled aircraft computer

    NASA Technical Reports Server (NTRS)

    Cogan, Bruce R. (Inventor)

    2010-01-01

    A low-cost, easily retrofit Propulsion Controlled Aircraft (PCA) system for use on a wide range of commercial and military aircraft consists of an propulsion controlled aircraft computer that reads in aircraft data including aircraft state, pilot commands and other related data, calculates aircraft throttle position for a given maneuver commanded by the pilot, and then displays both current and calculated throttle position on a cockpit display to show the pilot where to move throttles to achieve the commanded maneuver, or is automatically sent digitally to command the engines directly.

  8. Development of an LS-DYNA Model of an ATR42-300 Aircraft for Crash Simulation

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.

    2004-01-01

    This paper describes the development of an LS-DYNA simulation of a vertical drop test of an ATR42-300 twin-turboprop high-wing commuter-class airplane. A 30-ft/s drop test of this aircraft was performed onto a concrete impact surface at the FAA Technical Center on July 30, 2003. The purpose of the test was to evaluate the structural response of a commuter-class aircraft when subjected to a severe, but survivable, impact. The aircraft was configured with crew and passenger seats, anthropomorphic test dummies, forward and aft luggage, instrumentation, and onboard data acquisition systems. The wings were filled with approximately 8,700 lb. of water to represent the fuel and the aircraft weighed a total of 33,200 lb. The model, which consisted of 57,643 nodes and 62,979 elements, was developed from direct measurements of the airframe geometry, over a period of approximately 8 months. The seats, dummies, luggage, fuel, and other ballast were represented using concentrated masses. Comparisons were made of the structural deformation and failure behavior of the airframe, as well as selected acceleration time history responses.

  9. Euler Technology Assessment for Preliminary Aircraft Design-Unstructured/Structured Grid NASTD Application for Aerodynamic Analysis of an Advanced Fighter/Tailless Configuration

    NASA Technical Reports Server (NTRS)

    Michal, Todd R.

    1998-01-01

    This study supports the NASA Langley sponsored project aimed at determining the viability of using Euler technology for preliminary design use. The primary objective of this study was to assess the accuracy and efficiency of the Boeing, St. Louis unstructured grid flow field analysis system, consisting of the MACGS grid generation and NASTD flow solver codes. Euler solutions about the Aero Configuration/Weapons Fighter Technology (ACWFT) 1204 aircraft configuration were generated. Several variations of the geometry were investigated including a standard wing, cambered wing, deflected elevon, and deflected body flap. A wide range of flow conditions, most of which were in the non-linear regimes of the flight envelope, including variations in speed (subsonic, transonic, supersonic), angles of attack, and sideslip were investigated. Several flowfield non-linearities were present in these solutions including shock waves, vortical flows and the resulting interactions. The accuracy of this method was evaluated by comparing solutions with test data and Navier-Stokes solutions. The ability to accurately predict lateral-directional characteristics and control effectiveness was investigated by computing solutions with sideslip, and with deflected control surfaces. Problem set up times and computational resource requirements were documented and used to evaluate the efficiency of this approach for use in the fast paced preliminary design environment.

  10. Subsonic Aircraft Safety Icing Study

    NASA Technical Reports Server (NTRS)

    Jones, Sharon Monica; Reveley, Mary S.; Evans, Joni K.; Barrientos, Francesca A.

    2008-01-01

    NASA's Integrated Resilient Aircraft Control (IRAC) Project is one of four projects within the agency s Aviation Safety Program (AvSafe) in the Aeronautics Research Mission Directorate (ARMD). The IRAC Project, which was redesigned in the first half of 2007, conducts research to advance the state of the art in aircraft control design tools and techniques. A "Key Decision Point" was established for fiscal year 2007 with the following expected outcomes: document the most currently available statistical/prognostic data associated with icing for subsonic transport, summarize reports by subject matter experts in icing research on current knowledge of icing effects on control parameters and establish future requirements for icing research for subsonic transports including the appropriate alignment. This study contains: (1) statistical analyses of accident and incident data conducted by NASA researchers for this "Key Decision Point", (2) an examination of icing in other recent statistically based studies, (3) a summary of aviation safety priority lists that have been developed by various subject-matter experts, including the significance of aircraft icing research in these lists and (4) suggested future requirements for NASA icing research. The review of several studies by subject-matter experts was summarized into four high-priority icing research areas. Based on the Integrated Resilient Aircraft Control (IRAC) Project goals and objectives, the IRAC project was encouraged to conduct work in all of the high-priority icing research areas that were identified, with the exception of the developing of methods to sense and document actual icing conditions.

  11. Aircraft Lightning Electromagnetic Environment Measurement

    NASA Technical Reports Server (NTRS)

    Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.

    2011-01-01

    This paper outlines a NASA project plan for demonstrating a prototype lightning strike measurement system that is suitable for installation onto research aircraft that already operate in thunderstorms. This work builds upon past data from the NASA F106, FAA CV-580, and Transall C-180 flight projects, SAE ARP5412, and the European ILDAS Program. The primary focus is to capture airframe current waveforms during attachment, but may also consider pre and post-attachment current, electric field, and radiated field phenomena. New sensor technologies are being developed for this system, including a fiber-optic Faraday polarization sensor that measures lightning current waveforms from DC to over several Megahertz, and has dynamic range covering hundreds-of-volts to tens-of-thousands-of-volts. A study of the electromagnetic emission spectrum of lightning (including radio wave, microwave, optical, X-Rays and Gamma-Rays), and a compilation of aircraft transfer-function data (including composite aircraft) are included, to aid in the development of other new lightning environment sensors, their placement on-board research aircraft, and triggering of the onboard instrumentation system. The instrumentation system will leverage recent advances in high-speed, high dynamic range, deep memory data acquisition equipment, and fiber-optic interconnect.

  12. An advanced pitch change mechanism incorporating a hybrid traction drive

    NASA Technical Reports Server (NTRS)

    Steinetz, B. M.; Loewenthal, S. H.; Sargisson, D. F.; White, G.

    1984-01-01

    A design of a propeller pitch control mechanism is described that meets the demanding requirements of a high-power, advanced turboprop. In this application, blade twisting moment torque can be comparable to that of the main reduction gearbox output: precise pitch control, reliability and compactness are all at a premium. A key element in the design is a compact, high-ratio hybrid traction drive which offers low torque ripple and high torsional stiffness. The traction drive couples a high speed electric motor/alternator unit to a ball screw that actuates the blade control links. The technical merits of this arrangement and the performance characteristics of the traction drive are discussed.

  13. Unmanned aircraft systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unmanned platforms have become increasingly more common in recent years for acquiring remotely sensed data. These aircraft are referred to as Unmanned Airborne Vehicles (UAV), Remotely Piloted Aircraft (RPA), Remotely Piloted Vehicles (RPV), or Unmanned Aircraft Systems (UAS), the official term used...

  14. Jet aircraft emissions during cruise: Present and future

    NASA Technical Reports Server (NTRS)

    Grobman, J. S.

    1975-01-01

    Forecasts of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are compared to cruise emission for present day aircraft. The forecasts are based on: (1) knowledge of emission characteristics of combustors and augmentors; (2) combustion research in emission reduction technology, and (3) trends in projected engine designs for advanced subsonic or supersonic commercial aircraft. Recent progress that was made in the evolution of emissions reduction technology is discussed.

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

    NASA Technical Reports Server (NTRS)

    Gray, D. E.

    1976-01-01

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

  16. Energy absorption studied to reduce aircraft crash forces

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The NASA/FAA aircraft safety reseach programs for general aviation aircraft are discussed. Energy absorption of aircraft subflooring and redesign of interior flooring are being studied. The testing of energy absorbing configurations is described. The three NASA advanced concepts performed at neary the maximum possible amount of energy absorption, and one of two minimum modifications concepts performed well. Planned full scale tests are described. Airplane seat concepts are being considered.

  17. Smart aircraft fastener evaluation (SAFE) system: a condition-based corrosion detection system for aging aircraft

    NASA Astrophysics Data System (ADS)

    Schoess, Jeffrey N.; Seifert, Greg; Paul, Clare A.

    1996-05-01

    The smart aircraft fastener evaluation (SAFE) system is an advanced structural health monitoring effort to detect and characterize corrosion in hidden and inaccessible locations of aircraft structures. Hidden corrosion is the number one logistics problem for the U.S. Air Force, with an estimated maintenance cost of $700M per year in 1990 dollars. The SAFE system incorporates a solid-state electrochemical microsensor and smart sensor electronics in the body of a Hi-Lok aircraft fastener to process and autonomously report corrosion status to aircraft maintenance personnel. The long-term payoff for using SAFE technology will be in predictive maintenance for aging aircraft and rotorcraft systems, fugitive emissions applications such as control valves, chemical pipeline vessels, and industrial boilers. Predictive maintenance capability, service, and repair will replace the current practice of scheduled maintenance to substantially reduce operational costs. A summary of the SAFE concept, laboratory test results, and future field test plans is presented.

  18. Survival analysis of aging aircraft

    NASA Astrophysics Data System (ADS)

    Benavides, Samuel

    This study pushes systems engineering of aging aircraft beyond the boundaries of empirical and deterministic modeling by making a sharp break with the traditional laboratory-derived corrosion prediction algorithms that have shrouded real-world failures of aircraft structure. At the heart of this problem is the aeronautical industry's inability to be forthcoming in an accurate model that predicts corrosion failures in aircraft in spite of advances in corrosion algorithms or improvements in simulation and modeling. The struggle to develop accurate corrosion probabilistic models stems from a multitude of real-world interacting variables that synergistically influence corrosion in convoluted and complex ways. This dissertation, in essence, offers a statistical framework for the analysis of structural airframe corrosion failure by utilizing real-world data while considering the effects of interacting corrosion variables. This study injects realism into corrosion failures of aging aircraft systems by accomplishing four major goals related to the conceptual and methodological framework of corrosion modeling. First, this work connects corrosion modeling from the traditional, laboratory derived algorithms to corrosion failures in actual operating aircraft. This work augments physics-based modeling by examining the many confounding and interacting variables, such as environmental, geographical and operational, that impact failure of airframe structure. Examined through the lens of censored failure data from aircraft flying in a maritime environment, this study enhances the understanding between the triad of the theoretical, laboratory and real-world corrosion. Secondly, this study explores the importation and successful application of an advanced biomedical statistical tool---survival analysis---to model censored corrosion failure data. This well-grounded statistical methodology is inverted from a methodology that analyzes survival to one that examines failures. Third, this

  19. Aircraft landing gear systems

    NASA Technical Reports Server (NTRS)

    Tanner, John A. (Editor)

    1990-01-01

    Topics presented include the laboratory simulation of landing gear pitch-plane dynamics, a summary of recent aircraft/ground vehicle friction measurement tests, some recent aircraft tire thermal studies, and an evaluation of critical speeds in high-speed aircraft. Also presented are a review of NASA antiskid braking research, titanium matrix composite landing gear development, the current methods and perspective of aircraft flotation analysis, the flow rate and trajectory of water spray produced by an aircraft tire, and spin-up studies of the Space Shuttle Orbiter main gear tire.

  20. Lightweight diesel aircraft engines for general aviation

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  1. The drive for Aircraft Energy Efficiency

    NASA Technical Reports Server (NTRS)

    James, R. L., Jr.; Maddalon, D. V.

    1984-01-01

    NASA's Aircraft Energy Efficiency (ACEE) program, which began in 1976, has mounted a development effort in four major transport aircraft technology fields: laminar flow systems, advanced aerodynamics, flight controls, and composite structures. ACEE has explored two basic methods for achieving drag-reducing boundary layer laminarization: the use of suction through the wing structure (via slots or perforations) to remove boundary layer turbulence, and the encouragement of natural laminar flow maintenance through refined design practices. Wind tunnel tests have been conducted for wide bodied aircraft equipped with high aspect ratio supercritical wings and winglets. Maneuver load control and pitch-active stability augmentation control systems reduce fuel consumption by reducing the drag associated with high aircraft stability margins. Composite structures yield lighter airframes that in turn call for smaller wing and empennage areas, reducing induced drag for a given payload. In combination, all four areas of development are expected to yield a fuel consumption reduction of 40 percent.

  2. Low Reynolds number, long endurance aircraft design

    SciTech Connect

    Foch, R.J.; Ailinger, K.G. )

    1992-02-01

    Airplanes are typically designed to maximize range at the highest practical cruising speed. However, several missions require extended duration rather than range, and favor the slowest possible cruise speed. Such missions include surveillance, radio relay, and ship's electronic decoy. These missions are ideally suited for advanced technology unmanned aircraft, either remotely piloted or autonomous. Feasibility studies have been conducted and flight demonstrator prototypes of such unique aircraft have been under steady research and development at the Naval Research Laboratory since 1978. This paper discusses the design aspects and tradeoffs unique to small, slow speed long endurance unmanned aircraft operating at wing chord Reynolds numbers between 150,000 and 500,000. Additionally, many of these low Reynolds number-driven design features have applicability to high altitude, long endurance aircraft. 6 refs.

  3. Aircraft Cabin Turbulence Warning Experiment

    NASA Technical Reports Server (NTRS)

    Bogue, Rodney K.; Larcher, Kenneth

    2006-01-01

    New turbulence prediction technology offers the potential for advance warning of impending turbulence encounters, thereby allowing necessary cabin preparation time prior to the encounter. The amount of time required for passengers and flight attendants to be securely seated (that is, seated with seat belts fastened) currently is not known. To determine secured seating-based warning times, a consortium of aircraft safety organizations have conducted an experiment involving a series of timed secured seating trials. This demonstrative experiment, conducted on October 1, 2, and 3, 2002, used a full-scale B-747 wide-body aircraft simulator, human passenger subjects, and supporting staff from six airlines. Active line-qualified flight attendants from three airlines participated in the trials. Definitive results have been obtained to provide secured seating-based warning times for the developers of turbulence warning technology

  4. Trends in aircraft noise control

    NASA Technical Reports Server (NTRS)

    Hubbard, H. H.; Conrad, E. W.

    1975-01-01

    Flight vehicles are characterized according to their manner of operation and type of propulsion system; and their associated sources of noise are identified. Available noise reduction technology as it relates to engine cycle design and to powerplant component design is summarized. Such components as exhaust jets, fans, propellers, rotors, blown flaps, and reciprocating-engine exhausts are discussed, along with their noise reduction potentials. Significant aircraft noise reductions are noted to have been accomplished by the application of available technology in support of noise certification rules. Further noise reductions to meet more stringent future noise regulations will require substantial additional technology developments. Improved analytical prediction methods, and well-controlled validation experiments supported by advanced-design aeroacoustic facilities, are required as a basis for an effective integrated systems approach to aircraft noise control.

  5. Trends in transport aircraft avionics

    NASA Technical Reports Server (NTRS)

    Berkstresser, B. K.

    1973-01-01

    A survey of avionics onboard present commercial transport aircraft was conducted to identify trends in avionics systems characteristics and to determine the impact of technology advances on equipment weight, cost, reliability, and maintainability. Transport aircraft avionics systems are described under the headings of communication, navigation, flight control, and instrumentation. The equipment included in each section is described functionally. However, since more detailed descriptions of the equipment can be found in other sources, the description is limited and emphasis is put on configuration requirements. Since airborne avionics systems must interface with ground facilities, certain ground facilities are described as they relate to the airborne systems, with special emphasis on air traffic control and all-weather landing capability.

  6. Small transport aircraft technology

    NASA Technical Reports Server (NTRS)

    Williams, L. J.

    1983-01-01

    Information on commuter airline trends and aircraft developments is provided to upgrade the preliminary findings of a NASA-formed small transport aircraft technology (STAT) team, established to determine whether the agency's research and development programs could help commuter aircraft manufacturers solve technical problems related to passenger acceptance and use of 19- to 50-passenger aircraft. The results and conclusions of the full set of completed STAT studies are presented. These studies were performed by five airplane manufacturers, five engine manufacturers, and two propeller manufacturers. Those portions of NASA's overall aeronautics research and development programs which are applicable to commuter aircraft design are summarized. Areas of technology that might beneficially be expanded or initiated to aid the US commuter aircraft manufacturers in the evolution of improved aircraft for the market are suggested.

  7. Compilation of energy efficient concepts in advanced aircraft design and operations. Volume I. Technical report. Final report, 10 March-5 November 1980

    SciTech Connect

    Clyman, M.; Einhorn, S.J.; Shultz, R.S.

    1980-11-05

    This final report (contained in two volumes) presents the results of research into published literature. The search addressed the technologies necessary to support next generation (IOC 1990+) air vehicle design and operation concepts that will reduce the requirement for natural petroleum-derived energy. The Advanced Concepts Evaluation (ACE) Data Base consists of 599 unique abstracts listed as 948 entries. The ACE Data Base is arranged into eleven areas of RandD effort, each subdivided into Navy and non-Navy funded programs. Volume I includes introduction, Data Bases searched, research methodology for creation of the ACE Data Base, summary of search results, conclusions and recommendations. This volume contains an appendix of search strategies utilized.

  8. The cetaceopteryx: A global range military transport aircraft

    NASA Technical Reports Server (NTRS)

    Brivkalns, Chad; English, Nicole; Kazemi, Tahmineh; Kopel, Kim; Kroger, Seth; Ortega, ED

    1993-01-01

    This paper presents a design of a military transport aircraft capable of carrying 800,000 lbs of payload from any point in the United States to any other point in the world. Such massive airlift requires aggressive use of advanced technology and a unique configuration. The Cetaceopteyx features a joined wing, canard and six turbofan engines. The aircraft has a cost 1.07 billion (1993) dollars each. This paper presents in detail the mission description, preliminary sizing, aircraft configuration, wing design, fuselage design, empennage design, propulsion system, landing gear design, structures, drag, stability and control, systems layout, and cost analysis of the aircraft.

  9. Aeroacoustics of advanced propellers

    NASA Technical Reports Server (NTRS)

    Groeneweg, John F.

    1990-01-01

    The aeroacoustics of advanced, high speed propellers (propfans) are reviewed from the perspective of NASA research conducted in support of the Advanced Turboprop Program. Aerodynamic and acoustic components of prediction methods for near and far field noise are summarized for both single and counterrotation propellers in uninstalled and configurations. Experimental results from tests at both takeoff/approach and cruise conditions are reviewed with emphasis on: (1) single and counterrotation model tests in the NASA Lewis 9 by 15 (low speed) and 8 by 6 (high speed) wind tunnels, and (2) full scale flight tests of a 9 ft (2.74 m) diameter single rotation wing mounted tractor and a 11.7 ft (3.57 m) diameter counterrotation aft mounted pusher propeller. Comparisons of model data projected to flight with full scale flight data show good agreement validating the scale model wind tunnel approach. Likewise, comparisons of measured and predicted noise level show excellent agreement for both single and counterrotation propellers. Progress in describing angle of attack and installation effects is also summarized. Finally, the aeroacoustic issues associated with ducted propellers (very high bypass fans) are discussed.

  10. Flow prediction for propfan engine installation effects on transport aircraft at transonic speeds

    NASA Technical Reports Server (NTRS)

    Samant, S. S.; Yu, N. J.

    1986-01-01

    An Euler-based method for aerodynamic analysis of turboprop transport aircraft at transonic speeds has been developed. In this method, inviscid Euler equations are solved over surface-fitted grids constructed about aircraft configurations. Propeller effects are simulated by specifying sources of momentum and energy on an actuator disc located in place of the propeller. A stripwise boundary layer procedure is included to account for the viscous effects. A preliminary version of an approach to embed the exhaust plume within the global Euler solution has also been developed for more accurate treatment of the exhaust flow. The resulting system of programs is capable of handling wing-body-nacelle-propeller configurations. The propeller disks may be tractors or pushers and may represent single or counterrotation propellers. Results from analyses of three test cases of interest (a wing alone, a wing-body-nacelle model, and a wing-nacelle-endplate model) are presented. A user's manual for executing the system of computer programs with formats of various input files, sample job decks, and sample input files is provided in appendices.

  11. 77 FR 6669 - Airworthiness Directives; Honeywell International Inc. TPE331-10 and TPE331-11 Series Turboprop...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-09

    ... to the specified products. That NPRM published in the Federal Register on August 9, 2011 (76 FR 48749... Executive Order 12866, (2) Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR.... FOR FURTHER INFORMATION CONTACT: Joseph Costa, Aerospace Engineer, Los Angeles Aircraft...

  12. Developing and utilizing an Euler computational method for predicting the airframe/propulsion effects for an aft-mounted turboprop transport. Volume 2: User guide

    NASA Technical Reports Server (NTRS)

    Chen, H. C.; Neback, H. E.; Kao, T. J.; Yu, N. Y.; Kusunose, K.

    1991-01-01

    This manual explains how to use an Euler based computational method for predicting the airframe/propulsion integration effects for an aft-mounted turboprop transport. The propeller power effects are simulated by the actuator disk concept. This method consists of global flow field analysis and the embedded flow solution for predicting the detailed flow characteristics in the local vicinity of an aft-mounted propfan engine. The computational procedure includes the use of several computer programs performing four main functions: grid generation, Euler solution, grid embedding, and streamline tracing. This user's guide provides information for these programs, including input data preparations with sample input decks, output descriptions, and sample Unix scripts for program execution in the UNICOS environment.

  13. Raptors and aircraft

    USGS Publications Warehouse

    Smith, D.G.; Ellis, D.H.; Johnson, T.H.; Glinski, Richard L.; Pendleton, Beth Giron; Moss, Mary Beth; LeFranc, Maurice N.=; Millsap, Brian A.; Hoffman, Stephen W.

    1988-01-01

    Less than 5% of all bird strikes of aircraft are by raptor species, but damage to airframe structure or jet engine dysfunction are likely consequences. Beneficial aircraft-raptor interactions include the use of raptor species to frighten unwanted birds from airport areas and the use of aircraft to census raptor species. Many interactions, however, modify the raptor?s immediate behavior and some may decrease reproduction of sensitive species. Raptors may respond to aircraft stimuli by exhibiting alarm, increased heart rate, flushing or fleeing and occasionally by directly attacking intruding aircraft. To date, most studies reveal that raptor responses to aircraft are brief and do not limit reproduction; however, additional study is needed.

  14. Lightning effects on aircraft

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Direct and indirect effects of lightning on aircraft were examined in relation to aircraft design. Specific trends in design leading to more frequent lightning strikes were individually investigated. These trends included the increasing use of miniaturized, solid state components in aircraft electronics and electric power systems. A second trend studied was the increasing use of reinforced plastics and other nonconducting materials in place of aluminum skins, a practice that reduces the electromagnetic shielding furnished by a conductive skin.

  15. Characteristics of the advanced supersonic technology AST-105-1 configured for transpacific range with Pratt and Whitney aircraft variable stream control engines

    NASA Technical Reports Server (NTRS)

    Baber, H. T., Jr.

    1979-01-01

    Credence to systems weights and assurance that the noise study AST concept can be balanced were studied. Current titanium structural technology is assumed. A duct-burning turbofan variable stream control engine (VSCE), with noise reduction potential through use of a coannular nozzle was used. With 273 passengers, range of the AST-105-1 for a cruise Mach number of 2.62 is essentially transpacific. Lift-to-drag ratio is slightly higher than for previous AST configurations. It is trimmable over a center-of-gravity range of 4.7m (15.5 ft). Inherent high positive effective dihedral, typical of arrow-wing configurations in high-lift approach, would limit AST-105-1 to operating in crosswinds of 11.6 m/sec (22.4 kt), or less, with 75 percent of available lateral control. Normal power takeoff with cutback results in noise in excess of Federal Aviation Regulation Part 36 but less than for conventional procedure takeoff. Results of advanced (noncertificated) programmed throttle takeoff and approach procedures, not yet optimized, indicate that such can be an important additional method noise reduction.

  16. Cyberinfrastructure for Aircraft Mission Support

    NASA Technical Reports Server (NTRS)

    Freudinger, Lawrence C.

    2010-01-01

    Forth last several years NASA's Airborne Science Program has been developing and using infrastructure and applications that enable researchers to interact with each other and with airborne instruments via network communications. Use of these tools has increased near realtime situational awareness during field operations, resulting it productivity improvements, improved decision making, and the collection of better data. Advances in pre-mission planning and post-mission access have also emerged. Integrating these capabilities with other tools to evolve coherent service-oriented enterprise architecture for aircraft flight and test operations is the subject of ongoing efforts.

  17. Aircraft fire safety research

    NASA Technical Reports Server (NTRS)

    Botteri, Benito P.

    1987-01-01

    During the past 15 years, very significant progress has been made toward enhancing aircraft fire safety in both normal and hostile (combat) operational environments. Most of the major aspects of the aircraft fire safety problem are touched upon here. The technology of aircraft fire protection, although not directly applicable in all cases to spacecraft fire scenarios, nevertheless does provide a solid foundation to build upon. This is particularly true of the extensive research and testing pertaining to aircraft interior fire safety and to onboard inert gas generation systems, both of which are still active areas of investigation.

  18. Hypersonic aircraft design

    NASA Technical Reports Server (NTRS)

    Alkamhawi, Hani; Greiner, Tom; Fuerst, Gerry; Luich, Shawn; Stonebraker, Bob; Wray, Todd

    1990-01-01

    A hypersonic aircraft is designed which uses scramjets to accelerate from Mach 6 to Mach 10 and sustain that speed for two minutes. Different propulsion systems were considered and it was decided that the aircraft would use one full scale turbofan-ramjet. Two solid rocket boosters were added to save fuel and help the aircraft pass through the transonic region. After considering aerodynamics, aircraft design, stability and control, cooling systems, mission profile, and landing systems, a conventional aircraft configuration was chosen over that of a waverider. The conventional design was chosen due to its landing characteristics and the relative expense compared to the waverider. Fuel requirements and the integration of the engine systems and their inlets are also taken into consideration in the final design. A hypersonic aircraft was designed which uses scramjets to accelerate from Mach 6 to Mach 10 and sustain that speed for two minutes. Different propulsion systems were considered and a full scale turbofan-ramjet was chosen. Two solid rocket boosters were added to save fuel and help the aircraft pass through the transonic reqion. After the aerodynamics, aircraft design, stability and control, cooling systems, mission profile, landing systems, and their physical interactions were considered, a conventional aircraft configuration was chosen over that of a waverider. The conventional design was chosen due to its landing characteristics and the relative expense compared to the waverider. Fuel requirements and the integration of the engine systems and their inlets were also considered in the designing process.

  19. Weather data dissemination to aircraft

    NASA Technical Reports Server (NTRS)

    Mcfarland, Richard H.; Parker, Craig B.

    1990-01-01

    Documentation exists that shows weather to be responsible for approximately 40 percent of all general aviation accidents with fatalities. Weather data products available on the ground are becoming more sophisticated and greater in number. Although many of these data are critical to aircraft safety, they currently must be transmitted verbally to the aircraft. This process is labor intensive and provides a low rate of information transfer. Consequently, the pilot is often forced to make life-critical decisions based on incomplete and outdated information. Automated transmission of weather data from the ground to the aircraft can provide the aircrew with accurate data in near-real time. The current National Airspace System Plan calls for such an uplink capability to be provided by the Mode S Beacon System data link. Although this system has a very advanced data link capability, it will not be capable of providing adequate weather data to all airspace users in its planned configuration. This paper delineates some of the important weather data uplink system requirements, and describes a system which is capable of meeting these requirements. The proposed system utilizes a run-length coding technique for image data compression and a hybrid phase and amplitude modulation technique for the transmission of both voice and weather data on existing aeronautical Very High Frequency (VHF) voice communication channels.

  20. Q-FANSTM for general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Worobel, R.; Mayo, M. G.

    1973-01-01

    Continued growth of general aviation over the next 10 to 15 years is dependent on continuing improvement in aircraft safety, utility, performance and cost. Moreover, these advanced aircraft will need to conform to expected government regulations controlling propulsion system emissions and noise levels. An attractive compact low noise propulsor concept, the Q-FANTM when matched to piston, rotary combustion, or gas turbine engines opens up the exciting prospect of new, cleaner airframe designs for the next generation of general aviation aircraft which will provide these improvements and meet the expected noise and pollution restriction of the 1980 time period. New Q-FAN methodology which was derived to predict Q-FAN noise, weight and cost is presented. Based on this methodology Q-FAN propulsion system performance, weight, noise, and cost trends are discussed. Then the impact of this propulsion system type on the complete aircraft is investigated for several representative aircraft size categories. Finally, example conceptual designs for Q-FAN/engine integration and aircraft installations are presented.