Étude de l'écoulement de plasma supersonique et du déséquilibre autour d'une sphère.

Abstract

This thesis studies the flow of supersonic argon plasma over a sphere for application in the thermal spray field. A numerical model was developed to include the non-equilibrium state. The mass, momentum, energy and species conservation equations are solved taking into account the possible non-equilibrium state of the plasma. The transport variables are calculated with Hirschfelder et al.'s method based on the plasma's kinetics. Details on the numerical method used by the solver are given. The numerical model is validated including the physics of the flow, the chemical kinetics and the properties on which is based the plasma model. Supersonic plasma flows over a sphere are analyzed for different pressures, temperatures and Mach numbers to identify the influential factors on the drag coefficient and the chemical state of the plasma.