the shock standoff distance on spheres in hypervelocity flows have been made. Test flows of
air at 8.7 and 9.7 km/s were generated in the X2 expansion tunnel fitted with a Mach 10
nozzle. High-speed video images were analysed with a least-squares shape-fitting
algorithm. Assuming a spherical shock shape near the nose enabled increased resolution
measurements beyond the native pixel size. Normalised shock standoff distances, Δ Δ/DD …