Modeling and Experimental Investigation of the Effect of the Shape of the Internal Plasma Channel in a Plasma Installation with and without an Insert on the Parameters of a Jet

Abstract—For the production of metal powders with given sizes, it is necessary to analyze the relationship between the parameters of a plasma jet and the shape of the parts making up the internal channel of a plasma head. The same is true of the plasma processes of deposition of functional coatings and surface modification. Predictive computer modeling is one of the possibilities for investigating this relationship. We developed a computer model to describe these processes. A computer experiment is verified by conducting a full-scale experiment. The purpose of this work is to determine the influence of an additional insert placed in the gap between a cathode and a swirler on the parameters of a plasma jet (velocity, temperature). For this purpose, the following three versions of a plasma head design are considered: a basic version without an insert, and two versions with inserts of various shapes. These three plasma head configurations are compared. Plasma jet velocity and temperature distributions are determined for each version. A finite element method is used as a tool for solving the problem. To increase the accuracy of the computer experiment, two software packages are used and their results were compared. The choice of the finite element method is justified by the production practice of using it as a convenient tool for computational fluid dynamics. The Euler and Navier–Stokes equations are used to solve the problem numerically. The element size of the finite element grid used to divide a computational domain in the computer model is substantiated. The use of an additional insert is shown not to affect the parameters of a plasma jet, but its use can increase the service life of the equipment. The data obtained are consistent with the results presented in the works described earlier in the literature. Based on the results of this work, we make recommendations on powder production, the deposition of functional coatings, and surface modification by the plasma method, which are useful for the consumers and manufacturers of plasma equipment.