Effect of Particle Loading on DC Plasma Jet Profile During Low Pressure Plasma Deposition

Abstract

ABSTRACTIn modelization of plasma jet profiles and calculating individual particle trajectories and the local temperature profile of the injected particles it has generally been assumed that the particles injected into the plasma plume constitute a dilute system. The latter allows one to decouple the jet profile calculations from the particle trajectory and temperature calculations. However, in practice, low pressure plasma deposition is carried out under high loading conditions to minimize thermal energy losses. In addition, the plasma experiences local cooling and deceleration due to the high loading of the injected particles. The effect of powder injection rates (10 kg/hr -30 kg/hr) on the plasma and the particles was studied and numerically modeled. An axisymmertrical parabolic supersonic flow model with compressibility corrected k-… turbulence formulation was developed and used in this study to describe the jet flow. The exchange of energy and momentum between the injected particles and the plasma flow was treated by considering the source term of the governing equations. The effect of particle loading on the resulting jet profiles, particle trajectories and temperature profiles are presented and discussed.