Hypersonic Lee Surface Flow Phenomena over a Space Shuttle

Abstract

Leeward surface pressure and heat-transfer, flow separation, flowfield, and oil flow patterns of a space shuttle model are investigated experimentally at 0° <«<40° and a freestream Mach number of 6. The freestream Reynolds numbers were varied between 1.64 x 10 7 and 1.31 x 10 8 with different stagnation pressures. Results of experiment indicate two distinct types of flow separation and surface heating, depending on the angle of attack. Large axial components of velocity are also calculated in the separated flow region. Turbulent boundarylayer theory with a separation shape factor of 1.9 agrees with the heat-transfer measurements for a> 0°. Inviscid supersonic flow theory over an equivalent body geometry also agrees approximately with the profile measurements of the flowfield on the leeward plane of symmetry. Nomenclaturetransfer rate R^ -freestream unit Reynolds number per meter R ooL -freestream .Reynolds number based on model length T -temperature V = flow velocity X, Y, Z, = body axes a. = angle of attack 6 C = cone half-angle Subscripts P -conditions at peak heating s -separation / = total stagnation conditions t 2 = local stagnation conditions behind a normal shock w = conditions at the wall w 0 -laminar stagnation conditions oo = freestream conditions Ooo = freestream stagnation conditions I. IntroductionA complete description of the leeward surface heating xmof a space shuttle orbiter requires an understanding of 3-dimensional flow separation, vortices lifting off the surface, and effect of the freestream conditions on the flowfield. Initial research on lee-surface heating and flow separation over delta wing and several conceptual space shuttles has been done. '~6 Effects of the freestream Mach number, Reynolds number, and angle of attack were also discussed. Results of this previous work have shown that coiled-vortex sheets on the lee surface induce a downward flow of high energy air toward the centerline, which then turns outward, drawing low energy fluid from the center area. Two heating peaks, due to the existence of vortex system and boundary-layer transition of the reattachment flow, also were found. Wang 7 has shown

Staging of Two-Stage-to-Orbit Aerospace Plane

“…11,12) At staging with a slight angle of attack, the aerospace plane shows a configuration in which the space-side surface is 'windward' and the ground-side surface is 'leeward.' Pressure on the ground-side surface becomes lower than that on the spaceside surface.…”