Motion and heating of non-spherical particles in a plasma jet

Numerical simulation has been performed to study the motion and heating of non-spherical particles injected into a thermal plasma jet. The representative shapes of the non-spherical particles are taken to be oblate and prolate spheroids. It is shown that the increase in the drag force for an oblate spheroid compared with a sphere may appreciably affect the particle trajectories and thus affect the heating histories of injected particles. Although thermophoresis is often used to explain the phenomenon that particulate matter is hard to penetrate into a plasma flow, the present study shows that the thermophoretic force acting on a spheroidal particle is not important since it is notably less than the drag force.