Supersonic and Hypersonic Drag Coefficients for a Sphere

A comprehensive review of all relevant experimental data was completed, including recent for the drag coefficient a sphere in supersonic and hypersonic flows. The primary characterization parameter included relative Mach, Knudsen, Reynolds numbers based on velocity, diameter, other parameters. This showed that previously proposed nexus at number below 45 not strictly met, it instead weak transonic bump, which identified numerically first time with present simulations. New continuum-gas rarefied-gas simulations were conducted combined expanded dataset to improve quantitative description this region. results indicated quasi bridges rarefaction regime compressible flow regimes. then used develop new empirical models improved robustness accuracy as compared previous models. These are limited by critical associated boundary-layer transition sphere, found increase substantially Mach number.