Pressures, forces, moments and shock shapes for a geometrically matched sphere-cone and hyperboloid at Mach 20.3 in helium

An investigation was conducted to compare measured and predicted pressure distributions, forces and moments, and shock shapes on a geometrically matched sphere-cone and hyperboloid. A hyperboloid with a nose radius of 0.5276 in. and an asymptotic angle of 39.9871 deg was matched to a sphere-cone with a nose radius of 0.750 in. and a cone half-angle of 45 deg. Experimental results in helium at a free-stream Mach number of 20.3 and a free-stream unit Reynolds number of 6.83 x 10 to the 6th power per foot were combined with predicted results from a theoretical method to compare the two shapes. Comparisons of experimental results showed small differences in the two shapes, but the prediction method provided better results for the hyperboloid than for the sphere-cone.