Dust particles in high speed flows: Calculations of small particle reentry hydrodynamics

Numerical hydrodynamic calculations are used to model the dispersion of dust injected into a supersonic flow by the explosive disruption of a reentry vehicle. The particles constitute an initial dustball that expands into the existing velocity field after the detonation. Dust grains subsequently form a plume along the vehicle path. Particles in the bow, shock heat to the vaporization temperature because of drag and radiative heating, but particles in the dustball are shielded and consequently suffer only a small amount of vaporization. About 20% of the initial dust mass is vaporized. Application of the results to dust grains entrained in the air blast of a near surface nuclear explosion is briefly considered.