Numerical simulation of DC air plasma torch modes and plasma jet instability for thermal spraying technology

The article is dedicated to nonstationary simulation of DC air plasma torch. The mathematical model for the analysis of plasma jet instability is developed. The proposed 2D axisymmetric model demonstrates the physical processes taking place inside and in the outer region of the plasma torch. The influence of the power source parameters and anode geometry on voltage and plasma jet fluctuation is described. Simplified mathematical model is developed in order to assess the effect of the flow behavior on heat transfer processes. The developed model can be used for the design of plasma torches and their operation modes. The results of mathematical model verification are based on experimental studies