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Wind tunnel tests of swept wing jet transport aircraft model with four pod mounted engines under wing and external flow, jet augmented double slotted flap
The local flow field approaching an installed nozzle may vary from isolated test conditions, thereby affecting exhausting nozzle performance. An installation of general interest is a podded engine mounted near the aft lower surface of the wing. The effect of this installation on the performance of an auxiliary inlet ejector nozzle was investigated over a Mach number range of 0.7 to 1.3 by using a modified F-106B aircraft. Both floating and fixed-open door configurations were examined. The ejector nozzle trailing-edge flaps were simulated in the closed position with rigid structure which provided a boattail angle of 15 deg. Primary nozzle area was varied as exhaust gas temperature was varied between 982.2 and 2003.3 K.
Hydrodynamic journal bearing stability tests were conducted with 1.5 in. diameter, 1.5 in. long fixed geometry bearings in water at 80 F with zero load. Five fixed geometry bearings were rated in order of diminishing stability as follows: (1) three-tilted-lobe bearing (offset factor of 1.0), (2) herringbone-groove bearing, (3) one-segment, three-pod, shrouded Rayleigh-step bearing, (4) three-tilted-lobe journal with axial grooves (offset factor of 1.0) mated with a plain bearing, and (5) three-centrally-lobed bearing with axial grooves (offset factor of 0.5). The various parameters that affect the stability of each bearing configuration were investigated.
The results are presented from experimental aerodynamic investigations conducted on a 0.6-percent scale model of the MSC-040 space shuttle orbiter in a 14 inch trisonic wind tunnel. The purpose of the test program was to define the stability, control, and performance characteristics of the baseline MSC-040A orbiter configuration with proposed alternate wing pods, with several vertical tail configurations with and without flared rudders, and with upper wing surface flap deflections. Force and moment data and model base and balance cavity pressure data were obtained for a Mach range of 0.60 through 4.96 and dynamic pressure range of 465 through 1580 psf. Model attitude was varied from 0 to +34 degrees angle of attack at zero sideslip and -4 to +10 degrees angle of sideslip at 0, 10, 20, and 24 degrees angle of attack.
Tests were conducted in the NASA Langley continuous flow, variable density and Mach 20 helium tunnels. The orbiter was tested alone and with various side and tandem mounted tanks. Test conditions spanned a Reynolds number range which resulted in both laminar and turbulent flows. Experimental studies also examined the heat transfer problems associated with integration of the auxiliary propulsion system into the orbiter. Tests in the hypersonic shock tunnel investigated heating to cavities and heating from single and multiple hydrogen-oxygen plumes while tests, run as part of the configuration evaluation, examined the heating to wing pods.
Results are presented of a wind tunnel test on the directional stability of space shuttle booster configurations. The test was conducted at the 14-inch trisonic tunnel starting 6 December 1971 and continued through 11 December 1971 for a total of 66 occupancy hours. Configurations tested included a cylindrical body with two axisymmetrical noses, one with and without canopy, one delta wing, located in two positions, five vertical tails (including a V tail), two having split rudders, ventral fins, two sets of chines, three airbreathing engine pods, and rocket engine shrouds. The model scale was 0.003366.
The application of advanced technology to the design of an integrated secondary power system for future near-sonic long-range transports was investigated. The study showed that the highest payoff is achieved by utilizing secondary power equipment that contributes to minimum cruise drag. This is best accomplished by the use of the dedicated auxiliary power unit concept (inflight APU) as the prime power source for an airplane with a body-mounted engine or by the use of the internal engine generator concept (electrical power extraction from the propulsion engine) for an airplane with a wing-pod-mounted engine.
An experimental program was performed in which the individual performance of multiple VTOL model lift fans was measured. The model tested consisted of three 5.5 in. diameter tip-turbine driven model VTOL lift fans mounted chordwise in a two-dimensional wing to simulate a pod-type array. The performance data provided significant insight into possible thrust variations and losses caused by the presence of cover doors, adjacent fuselage panels, and adjacent fans. The effect of a partial loss of drive air supply (simulated gas generator failure) on fan performance was also investigated. The results of the tests demonstrated that lift fan installation variables and hardware can have a significant effect on the thrust of the individual fans.
Laser beam is emitted from pod on side of aircraft. Some scattered light returns to aircraft, but at shifted frequency caused by Doppler effect from local air speeds. Current work focuses on extending range, including investigations of effects of particle density, focusing, back scatter efficiency, absorption, and other factors.
A nozzle installation of general interest is a podded engine mounted near the aft lower surface of the wing. The effect of this installation on the performance of an auxiliary-inlet ejector nozzle with a clamshell flow diverter was investigated over a Mach number range of 0.6 to 1.3 by using a modified F-106B aircraft. The clamshell flow diverter was tested in a 17 deg position with double-hinged synchronized floating doors. The ejector nozzle trailing-edge flaps were simulated in the closed position with a rigid structure which provided a boattail angle of 10 deg. Primary nozzle area was varied as exhaust gas temperature was varied between 975 and 1561 K. With the nozzle in a subsonic cruise position, the nozzle gross thrust coefficient was 0.918 at a flight Mach number of 0.9.
Results are presented for a wind tunnel investigation of three single VTOL lift fan stages designed for the same overall total pressure ratio at different rotor tip speeds. The stages were tested in a model lift fan installed in a wing pod. The three stages had essentially the same aerodynamic performance along the operating line. However, differences in stage thrust characteristics were obtained when a variation in back pressure was imposed on the stages by cross-flow effects and thrust-vectoring louvers.
The advanced technology requirements for an advanced high speed commercial tranport engine are presented. The results of the phase 1 study effort cover the following areas: (1) statement of an airline's major objectives for future transport engines, (2) airline's method of evaluating engine proposals, (3) description of an optimum engine for a long range subsonic commercial transport including installation and critical design features, (4) discussion of engine performance problems and experience with performance degradation, (5) trends in engine and pod prices with increasing technology and objectives for the future, (6) discussion of the research objectives for composites, reversers, advanced components, engine control systems, and devices to reduce the impact of engine stall, and (7) discussion of the airline objectives for noise and pollution reduction.
An investigation of the static longitudinal aerodynamic characteristics of a semispan STOL jet transport wing-body with an upper-surface blown jet flap for lift augmentation was conducted in a low-speed wind tunnel having a 12-ft octagonal test section. The semispan swept wing had an aspect ratio of 3.92 (7.84 for the full span) and had two simulated turbofan engines mounted ahead of and above the wing in a siamese pod equipped with an exhaust deflector. The purpose of the deflector was to spread the engine exhaust into a jet sheet attached to the upper surface of the wing so that it would turn downward over the flap and provide lift augmentation. The wing also had optional boundary-layer control provided by air blowing through a thin slot over a full-span plain trailing-edge flap.
Preliminary results are presented for a reverberant-field noise investigation of three fan stages designed for the same overall total pressure ratio of 1.21 at different rotor tip speeds (750, 900, and 1050 ft/sec). The stages were tested statically in a 15-inch-diameter model lift fan installed in a wing pod located in the test section of a wind tunnel. Although the fan stages produced essentially the same design pressure ratio, marked differences were observed in the variation of fan noise with fan operating speed. At design speed, the forward-radiated sound power level was approximately the same for the 750 ft/sec and 900 ft/sec stages. For the 1050 ft/sec stage, the design-speed forward-radiated power level was about 7 db higher due to the generation of multiple pure tone noise.
Takeoff and landing performance characteristics and field length requirements were determined analytically for a jet STOL transport configuration with full-span, externally blown, tripleslotted flaps. The configuration had a high wing, high T-tail, and four pod-mounted high-bypass-ratio turbofan engines located under and forward of the wing. One takeoff and three approach and landing flap settings were evaluated. The effects of wing loading, thrust-to-weight ratio, weight, ambient temperature, altitude on takeoff and landing field length requirements are discussed.
Noise data measurements from a large scale lift fan transport model aircraft were made in the 40- by 80-foot wind tunnel. The model had two lift fans in deep inlets in the forward fuselage and two lift-cruise fans in pods on the aft fuselage. The noise data measurements are presented as listings and plots of sounds pressure level versus 1/3-octave center frequency.
The location and appendages of a lift fan on a V/STOL aircraft are expected to have a measurable effect on fan performance. To study such installation effects, an experimental program was performed in which the individual performance of multiple VTOL model lift fans was measured. The model tested consisted of three 13.97-cm diameter tip-turbine driven model VTOL lift fans mounted chordwise in a two-dimensional wing to simulate a pod-type array. The performance data provided significant insight into possible thrust variations and losses caused by the presence of cover doors, adjacent fuselage panels, and adjacent fans. The effect of a partial loss of drive air supply on fan performance was also investigated.
Static stability and control effectiveness characteristics of two 0.004 scale models of the vehicle 3 configuration are reported. The components investigated consisted of a single aft body, vertical/rudder, OMS pods with two interchangeable wings, four interchangeable forward bodies, four trimmers, and a spoiler. The test was conducted in 14 x 14 inch trisonic wind tunnel over a Mach number range from 0.6 to 4.96. Angles of attack from 0 to 60 degrees and angles of sideslip from -10 to 10 degrees at 0, 10, 20,30, and 40 degrees angle of attack were tested. Elevon, body flap, and speed brake deflection composed the parametric considerations. No grit was placed on the models during the test. The tabulated source data and incremental data figures are presented.