Arc cathode coupling and boundary conditions on predicted plasma flow field in a DC plasma Torch
R. Zhukovskii, C. Chazelas, V. Rat, A Vardelle
University of Limoges (Limoges, France)
Abstract
A predictive model of a DC non-transferred plasma torch operation must account for the process parameters and torch geometry on the arc behavior and plasma jet flow fields. The coupling of the electromagnetic and heat transfer phenomena in the cathode and gas phase is generally based on current density and temperature profiles imposed on the cathode surface, although it is difficult to experimentally check these values. An alternative is to include the cathode in the computational domain and impose the current density ( I / S) on its rear surface S and solve coupled equations of electromagnetism and energy conservation in the solid and fluid parts.This work deals with a 3D time-dependent model of a non-transferred plasma torch operation and seeks to study the influence of the electromagnetic and thermal coupling between the arc and cathode on the development of the plasma jet at the cathode tip.