Some Features of Supersonic and Hypersonic Flow About Blunted Cones

Abstract

For a family of cones of various semiapex angles blunted by spherical caps, shock shapes and surface pressure distributions have been obtained from both the Belotserkovskii method and experiment. These results are used to study convergence to conical flow. Conditions leading to both overexpansion and underexpansion on the surface with respect to the asymptotic conical pressures are described as well as conditions leading to bow shock inflection points. Conditions also exist for which a second shock may occur, or for which the sonic line cannot touch the body surface. The implications of these conditions for various blunt-body methods are discussed. For cones blunted in such a manner as to keep the flow entirely supersonic, the flow field is found to exhibit certain similarities with that for genuine blunting. This is related to the fact that the surface entropy layer for blunt bodies can be most influential, in determining surface pressure, in the interior of the flow field rather than near the surface.