Particle trajectories, heating, and breakup in hypersonic shock layers

Abstract

An analysis is made of the motion of small, spherical, noninteracting solid or liquid particles through hypersonic flowfields over spheres and cones. It is shown that the motion of the particles depends only on the density ratio across the shock and a dimensionless ballistic parameter. Approximate solutions to the particle equations of motion are obtained in closed form in terms of these parameters for two flow configurations, a sharpcone and the stagnation region of a sphere. A technique is derived for the determination of the aerodynamic heating and melting (or vaporization) of the particles as they traverse the shock layer. Results for the particle mass loss as a result of heating are presented for the stagnation region, the more severe heating environment. Existing correlations of experimental data on the breakup of drops due to aerodynamic forces are used to predict the extent of raindrop breakup in the shock layer.