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Results for “WING FLAPS, SLOTTED - FULL-SPAN”

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

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At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Noise reduction tests of large-scale-model externally blown flap using trailing-edge blowing and partial flap slot covering

Noise data were obtained with a large-scale cold-flow model of a two-flap, under-the-wing, externally blown flap proposed for use on future STOL aircraft. The noise suppression effectiveness of locating a slot conical nozzle at the trailing edge of the second flap and of applying partial covers to the slots between the wing and flaps was evaluated. Overall-sound-pressure-level reductions of 5 db occurred below the wing in the flyover plane. Existing models of several noise sources were applied to the test results. The resulting analytical relation compares favorably with the test data. The noise source mechanisms were analyzed and are discussed.

Mckinzie, D. J., Jr.↗
NASA NTRS1972

Low-speed aerodynamic characteristics of a model having a 42 deg swept low wing with a supercritical airfoil, double-slotted flaps, and a T-tail

A low speed wind tunnel test was conducted in the Langley V/STOL tunnel to determine the static longitudinal and lateral stability characteristics of a general research model which simulated an advance configuration for a commercial transport airplane with a T tail. The model had a 42 deg swept, aspect ratio 6.78 wing with a supercritical airfoil and a high lift system which consisted of a leading edge slat and a double slotted flap. Various slat and flap deflection combinations represented clean, take off, and landing configurations. Effects on the longitudinal and lateral aerodynamic characteristics were determined for two flow through, simulated engine nacelles located on the sides of the fuselage near the rear of the model.

Fournier, P. G.↗
NASA NTRS1973

Wind tunnel investigation of a large-scale 25 deg swept-wing jet transport model with an external blowing triple-slotted flap

An investigation has been conducted to determine the aerodynamic characteristics of a large-scale subsonic jet transport model with an externally blown triple-slotted flap. The lift of the model was augmented by the turbofan engine exhaust impingement on the flap surface. The model had a 25 deg swept wing of aspect ratio 7.28 and four turbofan engines. The model was tested with two flap extents. One extended from 0.11 to 1.00 of the wing semispan, and the other extended from 0.11 to 0.75 of the wing semispan with a single-slotted aileron from 0.75 to 1.00 of the wing semispan. The results were obtained for several flap deflections with and without the horizontal tail at gross thrust coefficients from 0 to 4.0. Longitudinal and lateral data are presented with three and four engines operating.

Aoyagi, K.↗
NASA NTRS1947

Effect of Slot-Entry Skirt Extensions on Aerodynamic Characteristics of a Wing Section of the XB-36 Airplane Equipped with a Double Slotted Flap

An investigation was made in the Langley two-dimensional low-turbulence tunnel on a wing section for the XB-36 airplane equipped with a double slotted flap to determine the effect on lift and drag of various slot-entry skirt extension. A skirt extension of 0.787 deg. was found to provide the best combination of high maximum lift with flap deflected and law drag with flap retracted. The data showed that the maximum lift at intermediate (20 deg. to 45 deg.) flap deflections was lowered considerably by the slot-entry extension; but at high flap deflections the effect was small. An increase in Reynolds number from 2.4 million to 6.0 million increased the maximum.lift coefficient at a flap deflection of 55 deg. from 3.12 to 3.30 and from 1.18 to 1.40 for the flap retracted condition, but did not greatly affect the maximum lift coefficient for intermediate flap deflections. The flap and fore flap load data indicated that the maximum lift coefficients at high flap deflections are limited by a breakdown in the flow over the .flaps.

Cahill, Jones F.↗
NASA NTRS1972

Wind tunnel investigation of a large scale 35 deg swept wing jet transport model with an external blowing triple slotted flap

An investigation was conducted to determine the aerodynamic characteristics of a large-scale subsonic jet transport model with an externally jet-augmented flap system that would augment lift and provide direct-lift control. The model had a 35 deg swept wing of aspect ratio 7.82 and two side-by-side engines mounted on a single pylon under each wing close to the fuselage. The lift of the flap system was augmented by jet engine exhaust impingement on the triple-slotted flap surfaces. The rearmost flap provided direct lift control. Results were obtained for several combinations of flap deflections at gross thrust coefficients from 0 to 2.0. Three-component longitudinal data are presented with four engines operating. Limited longitudinal and lateral data are presented for asymmetric and symmetric thrust conditions with three engines operating. For the same overall flap deflection, lift coefficient and maximum lift coefficient were improved 13 and 7 percent compared to coefficients obtained with a double-slotted flap configuration. A maximum lift coefficient of 6.3 was obtained at a gross thrust coefficient of 2.0. At the same flap deflection lateral and directional trim moment requirements with an engine inoperative were reduced 55 and 33 percent, respectively, compared to those with the engines located farther outboard on the wing. Trim moment requirements in pitch were also reduced significantly. However, pitching-moment instability occurred and increased with gross thrust coefficient.

Aoyagi, K.↗
NASA NTRS1996

High-Lift Systems on Commercial Subsonic Airliners

The early breed of slow commercial airliners did not require high-lift systems because their wing loadings were low and their speed ratios between cruise and low speed (takeoff and landing) were about 2:1. However, even in those days the benefit of high-lift devices was recognized. Simple trailing-edge flaps were in use, not so much to reduce landing speeds, but to provide better glide-slope control without sideslipping the airplane and to improve pilot vision over the nose by reducing attitude during low-speed flight. As commercial-airplane cruise speeds increased with the development of more powerful engines, wing loadings increased and a real need for high-lift devices emerged to keep takeoff and landing speeds within reasonable limits. The high-lift devices of that era were generally trailing-edge flaps. When jet engines matured sufficiently in military service and were introduced commercially, airplane speed capability had to be increased to best take advantage of jet engine characteristics. This speed increase was accomplished by introducing the wing sweep and by further increasing wing loading. Whereas increased wing loading called for higher lift coefficients at low speeds, wing sweep actually decreased wing lift at low speeds. Takeoff and landing speeds increased on early jet airplanes, and, as a consequence, runways worldwide had to be lengthened. There are economical limits to the length of runways; there are safety limits to takeoff and landing speeds; and there are speed limits for tires. So, in order to hold takeoff and landing speeds within reasonable limits, more powerful high-lift devices were required. Wing trailing-edge devices evolved from plain flaps to Fowler flaps with single, double, and even triple slots. Wing leading edges evolved from fixed leading edges to a simple Krueger flap, and from fixed, slotted leading edges to two- and three-position slats and variable-camber (VC) Krueger flaps. The complexity of high-lift systems probably peaked on the Boeing 747, which has a VC Krueger flap and triple-slotted, inboard and outboard trailing-edge flaps. Since then, the tendency in high-lift system development has been to achieve high levels of lift with simpler devices in order to reduce fleet acquisition and maintenance costs. The intent of this paper is to: (1) review available high-lift devices, their functions, and design criteria; (2) appraise high-lift systems presently in service on commercial air liners; (3) present personal study results on high-lift systems; (4) develop a weight and cost model for high-lift systems; and (5) discuss the development tendencies of future high-lift systems.

Rudolph, Peter K. C.↗