Published: 1975
Total Pages: 31
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A free-flying instrumented model was tested in a hypersonic facility at M = 5.30, 6.34 and 9.94 and Re = 300,000 to 1,200,000 ft. Aerodynamic lift, total drag and base drag coefficients were obtained together with detailed base pressure distribution measurements at angles of attack from 0 to 60 deg. The measured lift and drag coefficients showed good agreement with the modified Newtonian theory. The centerline base pressure/free-stream static pressure, psia distribution was nearly independent of the angle of attack from -10 to -30 deg but increased rapidly for all test conditions beyond alpha = -30 deg. For similar conditions at angle of attack and Reynolds number, an increase in Mach number resulted in an increase of the base pressure ratio. The measurements indicated a highly complex base flow region, and tentative explanation of the observed results was offered.