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At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Large-scale wind-tunnel investigation of the noise characteristics of a semispan wing equipped with an externally blown jet flap

A wind tunnel investigation was made of the noise characteristics of a 4.42 m(14.5 foot) semispan, externally-blown jet flap model. The model was equipped with a single 76.2 cm(30 inch) diameter, ducted fan with a 1.03 pressure ratio. The effects of flap size, fan vertical location, and forward speed on the noise characteristics were studied. The data from the investigation is presented in the form of tabulated one-third octave band frequency spectrums and perceived noise levels for each test condition.

Falarski, M. D.↗
NASA NTRS1974

A Flight Investigation of the STOL Characteristics of an Augmented Jet Flap STOL Research Aircraft

The flight test program objectives are: (1) To determine the in-flight aerodynamic, performance, and handling qualities of a jet STOL aircraft incorporating the augmented jet flap concept; (2) to compare the results obtained in flight with characteristics predicted from wind tunnel and simulator test results; (3) to contribute to the development of criteria for design and operation of jet STOL transport aircraft; and (4) to provide a jet STOL transport aircraft for STOL systems research and development. Results obtained during the first 8 months of proof-of-concept flight testing of the aircraft in STOL configurations are reported. Included are a brief description of the aircraft, fan-jet engines, and systems; a discussion of the aerodynamic, stability and control, and STOL performance; and pilot opinion of the handling qualities and operational characteristics.

Quigley, H. C.↗
NASA NTRS1974

Low-speed aerodynamics of the upper-surface blown jet flap

Review of the results of recent wind-tunnel investigations conducted to provide fundamental aerodynamic information on the upper-surface blown jet-flap concept incorporating high-bypass-ratio turbofan engines. The results of the investigations have shown the concept to have aerodynamic performance generally comparable to that of other externally blown high-lift systems. Some of the more critical problem areas associated with this concept are covered, and solutions which have been found for these problems are discussed.

Johnson, J. L., Jr.↗
NASA NTRS1975

Wind tunnel investigation of a twin engine straight wing upper surface blown jet flap configuration

An investigation was conducted in a full scale wind tunnel to determine the performance and aerodynamic characteristics of a twin engine, straight wing, upper surface blown jet flap configuration. The model had two simulated high bypass ratio turbofan engines with rectangular nozzles exhausting onto the upper surface of the wing at the 35 percent chord station. The model was tested with an aspect ratio 8.2 wing and with the wingtips removed to give an aspect ratio of 6.0.

Phelps, A. E., III↗
NASA NTRS1973

March 1971 wind tunnel tests of the Dorand DH 2011 jet flap rotor, volume 1

The results of wind tunnel tests, second series of tests performed in the NASA Ames 40 x 80 foot wind tunnel, of the DH 2011 jet-flap rotor are presented and analyzed. The tests have been focused on multicyclic effects and the capability of this rotor to reduce the vibratory loads and stresses in the blades. The reductions of the vibrations and stresses at tip speed ratio of 0.4 have attained 50%. The theory shows further reductions possible, reaching 80%. The results show that the performance characteristics after the modifications introduced since 1965 remained unchanged. The domain of investigation has been enlarged to include the tip speed ratios of 0.6 and 0.7. To analyze the complex aeroelastic phenomena a new analytical technique has been utilized to represent the mathematical model of the rotor. This technique, based on transfer matrices and transfer functions, appears very simple and it is believed that this analysis is applicable to many kinds of investigations involving large numbers of variables.

Kretz, M.↗
NASA NTRS1977

Static and wind-on tests of an upper-surface-blown jet-flap nozzle arrangement for use on the Quiet Clean Short-haul Experimental Engine (QCSEE)

The internal aerodynamic performance, the static turning characteristics, and the forward-speed characteristics of two 1/12-scale upper surface-blown jet-flap exhaust-nozzle arrangements designed for use on the Quiet Clean Short-Haul Experimental Engine (QCSEE) were investigated. The nozzles were equipped with interchangeable area-control side doors in the aft sidewalls of the nozzle so that the effective nozzle area could be varied over a wide range. A simulated wing was used to evaluate installation losses for the nozzles. A smoothly curved flap was attached to the trailing edge of the simulated wing to allow an evaluation of the static turning characteristics of the nozzle arrangement. Forward-speed effects on the jet turning characteristics of the QCSEE nozzles were evaluated by mounting a single engine on a semispan wing designed to be representative of a four-engine STOL transport configuration.

Phelps, A. E., III↗
NASA NTRS1973

Wind tunnel investigation of effects of variations in Reynolds number and leading-edge treatment on the aerodynamic characteristics of an externally blown jet-flap configuration

An investigation has been conducted in a full-scale tunnel to determine the effects of variations in Reynolds number and leading-edge treatment on the aerodynamic characteristics of an externally blown jet-flap transport configuration. The model had a double-slotted trailing-edge flap and was powered by four high-bypass-ratio turbofan engines. Tests were performed by using each of three leading-edge devices (a 30-percent-chord flap and 15- and 25-percent-chord slats) at Reynolds numbers from 0.47 x one million to 1.36 x one million thrust coefficients up to 3.5. The use of a 25-percent-chord slat was found to be more effective than a 15-percent-chord slat or a 30-percent-chord flap in extending the stall angle of attack and in minimizing the loss of lift after the stall. The large slat was also effective in reducing the rolling moments that occurred when the engine-out wing stalled first.

Parlett, L. P.↗
NASA NTRS1973

Wind tunnel investigation of an upper surface blown jet-flap powered-lift configuration

An investigation has been conducted in the Langley full-scale tunnel to determine the performance and static stability and control characteristics of a four-engine, upper surface blown jet-flap powered-lift configuration with a swept wing. The investigation included test performed over a range of angle of attack (-4 deg to 36 deg), angle of sideslip (-5 deg to 5 deg), and thrust coefficients (0 to 4.32) for both symmetric and engine-out power conditions and for horizontal and vertical tails both on and off. In addition to the four-engine tests, a few tests were made with the outboard engines removed to simulate a twin-engine powered-lift transport configuration.

Phelps, A. E., III↗
NASA NTRS1974

Aerodynamics of jet flap and rotating cylinder flap STOL concepts

The aerodynamic effectiveness of various propulsive lift concepts to provide for the low speed performance and control required for short takeoff and landing aircraft is discussed. The importance of the interrelationship between the propulsion system and aerodynamic components of the aircraft is stressed. The relative effectiveness of different lift concepts was evaluated through static and wind tunnel tests of various aerodynamic models and propulsion components, simulations of aircraft, and in some cases, flight testing of research aircraft incorporating the concepts under study. Results of large scale tests of lift augmentation devices are presented. The results of flight tests of STOL research aircraft with augmented jet flaps and rotating cylinder flaps are presented to show the steeper approach flight paths at low forward speeds.

Cook, W. L.↗
NASA NTRS1974

Pressure distribution of a twin-engine upper-surface blown jet-flap model

An investigation has been made to determine the chordwise and spanwise pressure distributions of a small-scale upper-surface blown jet-augmented flap STOL model. The model was powered by two simulated high-bypass-ratio turbofan engines mounted ahead of and above an unswept-untapered wing in a nacelle having a rectangular nozzle. The results of the investigation are presented as tabulated and plotted chordwise pressure distribution coefficients for nine spanwise stations.

Smith, C. C., Jr.↗
NASA NTRS1971

Aerodynamic characteristics of a large scale model with a swept wing and augmented jet flap

Data of tests of a large-scale swept augmentor wing model in the 40- by 80-foot wind tunnel are presented. The data includes longitudinal characteristics with and without a horizontal tail as well as results of preliminary investigation of lateral-directional characteristics. The augmentor flap deflection was varied from 0 deg to 70.6 deg at isentropic jet thrust coefficients of 0 to 1.47. The tests were made at a Reynolds number from 2.43 to 4.1 times one million.

Falarski, M. D.↗
NASA NTRS1976

Wind-tunnel investigation of aerodynamic performance, steady amd vibratory loads, surface temperatures, and acoustic characteristics of a large-scale twin-engine upper-surface blown jet-flap configuration

Static and wind-on tests were conducted to determine the aerodynamic characteristics of and the effects of jet impingement on the wing of a large scale upper surface blown configuration powered with an actual turbine engine. The wing and flaps were instrumented with experimental dual-sensing transducer units consisting of a fluctuating pressure gage, a vibratory accelerometer, and a surface mounted alumel thermocouple. Noise directivity and spectral content measurements were obtained for various flap configurations and various engine thrust settings to provide baseline noise data for other upper surface blown configurations.

Source record↗
NASA NTRS1983

Experimental wing and canard jet-flap aerodynamics

The effects of upper surface blowing on the aerodynamics of a 1/2-span wing/body/canard configuration are shown. The results expand a data base that is limited at high subsonic Mach numbers (M = 0.6-0.9), data that are needed if computational techniques are to be developed for the complex flowfields generated by jet blowing. At lift coefficients greater than about 1.0, the thrust removed drag coefficient was lower with jet blowing than without jet blowing. This favorable effect increased with increasing jet blowing coefficient, and, for a fixed coefficient, simultaneous wing/canard jet blowing was slightly more effective than blowing either surface alone.

Smeltzer, D. B.↗
NASA NTRS1972

Longitudinal aerodynamic characteristics of a large scale model with a swept wing and augmented jet flap in ground effect

The investigation of the in-ground-effect, longitudinal aerodynamic characteristics of a large scale swept augmentor wing model is presented, using 40 x 80 ft wind tunnel. The investigation was conducted at three ground heights; h/c equals 2.01, 1.61, and 1.34. The induced effect of underwing nacelles, was studied with two powered nacelle configurations. One configuration used four JT-15D turbofans while the other used two J-85 turbojet engines. Two conical nozzles on each J-85 were used to deflect the thrust at angles from 0 to 120 deg. Tests were also performed without nacelles to allow comparison with previous data from ground effect.

Falarski, M. D.↗
NASA NTRS1974

Preliminary static tests of a simulated upper-surface blown jet-flap configuration utilizing a full-size turbofan engine

The investigation was conducted to evaluate the static turning performance and the pressure and temperature environment of an upper-surface-blown wing and flap utilizing a small turbofan engine. The tests involved modifications of the engine primary nozzle designed to alleviate high temperature problems on the wing and flaps and yet provide acceptable static turning performance over the desired range of flap deflections and thrust conditions.

Shivers, J. P.↗
NASA NTRS1975

Static tests of a simulated upper surface blown jet-flap configuration utilizing a full-size turbofan engine

The investigation utilizing a small turbofan engine was conducted to evaluate static turning performance and pressure and temperature environment of an upper surface blown wing and flap segment. The tests involved modifications of the engine primary nozzle to alleviate high-temperature problems on the wing and flaps without adversely affecting static turning performance over the desired range of flap deflection and thrust condition.

Shivers, J. P.↗
NASA NTRS1976

Ground simulation and tunnel blockage for a jet-flapped, basic STOL model tested to very high lift coefficients

Ground effects experiments and large/small-tunnel interference studies were carried out on a model with a 20-inch (50.8 cm) span wing. The wing, which includes a highly deflected knee-blown flap can be fitted with unflapped tips and slats. A low-mounted tailplane can be fitted to the aft fuselage. Three-component balance meaurements, made with a fixed ground equipped with a single boundary-layer blowing slot, were compared with datum, moving-ground results. Good comparisons were obtained up to model blowing momentum coefficients of approximately two, after which the particular floor blowing settings used proved insufficient to prevent floor separation in the vicinity of the model. Skin friction measurements, taken routinely along the floor centerline, proved invaluable during the analysis of results, and their use is recommended as input to determination of floor BLC setting. A careful investigation was made of pitching moments, including tail-on, close-to-ground cases, with favorable results. Drag proved the most sensitive to the change from a moving to the boundary-layer controlled ground.

Hackett, J. E.↗