The Shock Shape And Shock Detachment Distance For Spheres And Flat Faced Bodies In Low Density Hypervelocity Argon Flow

An experimental investigation was made to determine the pressure distribution, shock shape, and shock detachment distance for spheres and the latter two characteristics for flatfaced bodies in a heated argon flow. The modified Newtonian approximation for the pressure distribution, which is strictly an empirical relationship, gives good results when applied to the first 60 degrees of a hemisphere under conditions where the body boundary layer and the shock layer merge. The natural flow visualization produced as a result of the high total temperature and consequent excitation of the argon enabled this study to be made. Photographs taken of the shocks generated by a series of spheres and flat-faced bodies were analyzed with a photo-densitometer to determine the shock shape and shock detachment distance. The blast analogy predicts a difference in the shape of shocks in argon and air at high Mach numbers and Reynolds numbers. An empirical relationship proposed by Love was used to calculate the shock shape in air for Mach numbers corresponding to those of the present investigation. (Author).