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Sleeman, W. C., Jr.

Publications and source records attributed to Sleeman, W. C., Jr..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Wing surface-jet interaction characteristics of an upper-surface blown model with rectangular exhaust nozzles and a radius flap

The wing surface jet interaction characteristics of an upper surface blown transport configuration were investigated in the Langley V/STOL tunnel. Velocity profiles at the inboard engine center line were measured for several chordwise locations, and chordwise pressure distributions on the flap were obtained. The model represented a four engine arrangement having relatively high aspect ratio rectangular spread, exhaust nozzles and a simple trailing edge radius flap.

Bloom, A. M.↗
NASA NTRS1976

Low-speed wind-tunnel investigation of the longitudinal stability characteristics of a model equipped with a variable-speed wing, 23 May 1949

The longitudinal stability characteristics of a complete model equipped with a variable sweep wings at angles of sweepback of 45 deg, 30 deg, 15 deg, and 0 deg investigated. Various wing modifications and an extern 1 flap arrangement designed to minimize the shift in neutral point accompanying the change in sweep angle were studied. The results indicate that stability at the stall was obtained at a sweep angle of 15 deg without recourse to stall control devices. The basic neutral point movement accompanying the change in sweep angle from 45 deg to 15 deg amounted to 56 percent of the mean aerodynamic chord (at zero sweep angle) and the most effective modification investigated only reduced this change to 47 percent of the chord. It appears, therefore, that for designs in which the fuselage is the major load carrying element some relative movement between the wing and center of gravity will be required to assure satisfactory stability at all sweep angles.

Donlan, C. J.↗
NASA NTRS1976

Upper-surface-blowing flow-turning performance

Jet exhaust flow-turning characteristics were determined for systematic variations in upper-surface blowing exhaust nozzles and trailing-edge flap configuration variables from experimental wind-off (static) flow studies. For conditions with parallel flow exhausting from the nozzle, jet height (as indicated by nozzle exit height) and flap radius were found to be the most important parameters relating to flow turning. Nonparallel flow from the nozzle, as obtained from an internal roof angle and/or side spread angle, had a large favorable effect on flow turning. Comparisons made between static turning results and wind tunnel aerodynamic studies of identical configurations indicated that static flow-turning results can be indicative of wind-on powered lift performance for both good and poor nozzle-flap combinations but, for marginal designs, can lead to overly optimistic assessment of powered lift potential.

Sleeman, W. C., Jr.↗
NASA NTRS1975

Low speed wind tunnel investigation of a four-engine upper surface blown model having swept wing and rectangular and D-shaped exhaust nozzles

A low speed investigation was conducted in the Langley V/STOL tunnel to determine the power-on static-turning and powered-lift aerodynamic performance of a four engine upper surface blown transport configuration. Initial tests with a D-shaped exhaust nozzle showed relatively poor flow-turning capability, and the D-nozzles were replaced by rectangular nozzles with a width-height ratio of 6.0. The high lift system consisted of a leading edge slat and two different trailing-edge-flap configurations. A double slotted flap with the gaps sealed was investigated and a simple radius flap was also tested. A maximum lift coefficient of approximately 9.3 was obtained for the model with the rectangular exhaust nozzles with both the double slotted flap deflected 50 deg and the radius flap deflected 90 deg.

Sleeman, W. C., Jr.↗
NASA NTRS1974

Low-speed aerodynamic characteristics of a transport configuration having a 42 deg swept supercritical airfoil wing and three tail height positions

A low speed investigation was conducted in the Langley V/STOL tunnel to define the static stability characteristics of an advanced high subsonic speed transport aircraft model in the cruise configuration (no high lift system). The wing of the model had 42 deg sweep of the quarter chord line, an aspect ratio of 6.78, and supercritical airfoil sections. Three different horizontal tail configurations (high, mid, and low) were investigated on the complete model and for the model with the wing removed in order to assess effects of the wing flow field on the tail contributions to both longitudinal and lateral stability characteristics. All the model configurations investigated were tested over an angle of attack range from approximately -5 to 23 deg. Some model configurations were also tested over an angle of attack range from about 11 to 38 deg in order to explore the aerodynamic characteristics in the deep stall region.

Fournier, P. G.↗
NASA NTRS1973

Effects of wing height on low-speed aerodynamic characteristics of a model having a 42 deg swept wing, a supercritical airfoil, double-slotted flaps, and a low tail

A low speed investigation was conducted in the Langley V/STOL tunnel to determine the static longitudinal lateral stability characteristics of a general research model with the wing in a high position and a low position on the fuselage. The model had a wing with a quarter chord sweep of 42 deg, an aspect ratio of 6.78, a supercritical airfoil, and a high lift system which consisted of a leading edge slat and a double slotted flap. Various slat and flap deflections represented clean, take off, and landing configurations. A 45 deg swept horizontal tail located slightly below the fuselage center line was investigated with both the low and high wing configurations.

Fournier, P. G.↗
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 NTRS1972

Flexible wings for transportation.

The possible uses of flexible wings for transportation of passengers and cargo from point to point on earth are discussed along with emergency applications of flexible wings in connection with conventional aircraft. Topics considered include gliding and soaring as a sport, towing of flexible-wing gliders for cargo delivery, powered flight with small aircraft having folding flexible wings, aerial dropping of personnel and cargo on flexible wings instead of parachutes, landing and recovery of rocket payloads by means of flexible wings, and use of flexible wings with ejection seats and as an emergency landing system for conventional aircraft.

Rogallo, F. M.↗
NASA NTRS1963

PARAWING AERODYNAMICS

Application of the tension structure concept for flexible wings to be used in spacecraft recovery and landing, emphasizing para-wing aerodynamics

FLEXIBLE WING↗