Acceleration of microparticles in a gasdynamic facility with high expansion of flow

Abstract

In addition to being used for achieving the traditional objective (developing a high-velocity steady flow with uniform transverse distribution of parameters), high-enthalpy aerodynamic facilities may be employed as devices which accelerate microparticles for implementing modern technological processes (for example, treating the surfaces of solids). The acceleration of particles to high velocities is accompanied by a decrease in the density of carrier gas and its deep cooling. In this paper, a physicomathematical model of two-phase flow is constructed, which takes into account the strong temperature dependence of the thermal properties of material of the dispersed phase (thermal conductivity coefficient and specific heat capacity in accordance with the Debye theory), as well as the possibility flow past particles at arbitrary values of Knudsen number (from continuous to free-molecule mode of flow). Numerical investigation results are given for the values of parameters, which are characteristic of a typical high-velocity aerogasdynamic facility and dielectric microparticles accelerated in this facility. Considered by way of example are the cases of two materials with particles of different sizes.