Accession Number : AD0687491

Title :   GAP EFFECTS OF A SHARP EDGED DELTA WING AT SUPERSONIC SPEEDS,

Corporate Author : ARA INC WEST COVINA CALIF

Personal Author(s) : Mazelsky,Bernard ; Chao,Chia-Chun ; Shen,Cheng-Chung

Report Date : FEB 1969

Pagination or Media Count : 58

Abstract : Sonic boom measurements were conducted to evaluate the effects of a leading slat with various degrees of camber and gap size between the slat and the main wing on a 70 deg swept delta wing at supersonic speeds. The model was sized for sonic boom measurements in a wind tunnel. In addition to these measurements, the model was instrumented with several pressure taps for indicating the flow through the gap. As a separate wind tunnel entry, force measurements were also taken to indicate the effect of the cambered slat on the pitch stability and lift-drag ratio. Due to the small size of the model required to measure the sonic boom, the gap configuration was such that the airflow was normal to the wing surface. For optimum lift and drag performance, the gap should be designed such that the flow from the upper surface should be tangential to the upper surface. A second model has been constructed to evaluate the lift-drag problem separately by increasing the size of the model such that the proper gap configurations can be fabricated. Regardless of the non-optimization of the gaps, the following results were established by this phase of the program. (1) The effect of camber results in an increase in (L/D)max. (2) The effect of Reynolds Number on (L/D)max is negligible when the gap is closed. However, for a very small gap, a slight increase in (L/D)max occurs with increasing Reynolds Number. (3) For the case of zero and 11 deg camber, the reduction of overpressure due to the gap is approximately 5%. For the case of the 7 deg camber, no reduction was apparent. (Author)

Descriptors :   (*WING SLOTS, SONIC BOOM), (*SONIC BOOM, DELTA WINGS), (*DELTA WINGS, SUPERSONIC CHARACTERISTICS), LEADING EDGES, MODEL TESTS, LIFT, DRAG, CAMBER, REYNOLDS NUMBER, PRESSURE, SHOCK WAVES, PITCH(MOTION), SWEPTBACK WINGS, ANGLE OF ATTACK

Subject Categories : Aerodynamics
      Aircraft
      Acoustics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE