The aerodynamic design and testing of a lifting swept wing-body configuration with shock free wing flow at M=1.20

A wing-body configuration has been designed, with the intention of giving economical cruise characteristics at low supersonic speeds. The design aim was to reduce the wave drag as far as possible by designing the wing and body in such a way that boundary layer separation and shocks on the wing are avoided, A wind tunnel model was made according to this design, consisting of a 55o swept warped wing mounted on an axially symmetric waisted body. The presentation of the wind tunnel test results has been confined to the design Mach number M = 1.20 and the design incidence α 2,5o. The experimental pressure distributions show good agreement with the theoretical pressure distributions except for a slight overexpansion on the wing uppersurfaoe near 30% of the chord and a compression on the wing lower surface. Due to these pressure deviations the measured wing lift is slightly higher than the calculated value. From the test results it appears that over the main part of the wing uppersurface the flow is supercritical. In spite of this the flow suggests no indication of the presence of shock waves. It can be concluded that the design aim of achieving a wing-body combination possessing good lift-drag charaoteristies at M = 1.20, has been fulfilled. Prepared for AGARD specialist meeting on transonic aerodynamics to be held in Paris 18-20 September I968.