A study of laminar near wakes.

Abstract

The near wake of a 0.05 nose bluntness ratio, 10° half-angle sphere cone has been investigated. Direct measurements of static temperatures and densities were obtained between the body base and four base diameters downstream using the electron beam excitation technique. The results indicate that the near wake static temperatures are sensitive functions of both Reynolds number and model surface temperature, but not of Mach number. Wake static temperatures decrease with increasing Reynolds number. The temperatures also decrease with decreasing wall temperature. Nose bluntness effects on wake temperatures have been studied experimentally. For 0.05, 0.23, and 0.3 nose bluntness ratio 9° and 10° half-angle sphere cones, the maximum temperatures in the wakes increased with increasing nose bluntness ratio. Measurements of base pressure and heat transfer also have been obtained. The base pressure ratio (P^/Poo) increased with increasing bluntness, increasing Mach number, and decreasing Reynolds number. The base heat transfer when correlated in terms of base flow parameters was found to be insensitive to variations in Mach number and wall temperature. Also, it was only weakly dependent on Reynolds number.