Numerical simulation of the argon-hydrogen plasma flow in the channel of RF inductively coupled plasma torch

The results of numerical simulation of plasma flow in the channel of technological radio frequency (RF) plasma torch with three coils and frequency at 3 MHz are presented. The mixture of argon with hydrogen is considered as the working gas at a variation of hydrogen volume fraction α from 0 to 10%. The distributions of electromagnetic fields and gas-dynamic parameters of the plasma flow are calculated. It is shown that when the amplitude of discharge current exceeds the critical value J_cr (depends on α), the regime of plasma flow transforms from the potential to vortical regime, in which a toroidal vortex is formed before or in the inductor zone. The dependence of the values of the critical current J_cr on the volume concentration of hydrogen α is established. The influences of volume fraction α and discharge current J_coil on the intensities and the position of the vortex center are determined.