Relaxation of an alkali-metal halide aerosol in a shock wave

Abstract

The interaction of a shock wave with an alkali-metal halide aerosol has been studied over a temperature range of 900–3600 K. The particle velocity relaxation and evaporation of aerosols of known size distribution were monitored with a light transmission technique.

Times for complete velocity relaxation were found to be comparable with total evaporation times. At temperatures above 1550 K, the total evaporation times were independent of the gas temperatures. At temperatures below 1550 K, an activation phenomenon was observed in the evaporation times.

Results were analysed using theoretical expressions for particle drag, heat transfer and particle evaporation. Expressions for the transition region in Knudsen number gave the best agreement with experiment.