Wall Temperature Effects On The Zero Lift Viscous Drag Of Blunted Cones In Rarefied Supersonic Flow PDF Download

Drag coefficient data for hemispherically blunted 15 degree semi-angle cones were obtained experimentally for a Mach number of 5.8. The Reynolds number based on the model base diameter ranged from 550 to 3700 and the ratio of the wall temperature to the stagnation temperature varied from 0.07 to 0.94. The drag was found to increase linearly with increasing wall temperature with the bluntest cones being most sensitive to the change in wall temperature. The percentage drag increase over the experimental temperature range was at least 11%, and as much as 19%, for all models tested. At a constant wall temperature ratio the drag coefficient was linearly dependent on the 'hypersonic viscous parameter' with the value for the sharp cone being adequately predicted by second order boundary layer theory. With the wall temperature ratio and the hypersonic viscous parameter fixed the viscous drag coefficient for blunted cones was found to be relatively independent of the bluntness ratio. (Author).