Numerical simulation of equilibrium air plasma flow in the induction chamber of a high-power plasmatron

Multi-parameter study on the subsonic equilibrium air plasma flows in the cylindrical discharge channel of an induction RF-plasmatron IPG-3 with the maximum operating power of 1 MW is presented. Simulations are carried out by numerical solution of full Navier–Stokes equations coupled with a two-dimensional equation for high-frequency electric field; the discretization of the equations is performed on a staggered Cartesian mesh. An effective method for calculation of the transport coefficients for ionized multi-component air (including the plasma conductivity) in the temperature range 300–15000 K is applied, with the higher-order approximations by the Sonine polynomial in the Chapman–Enskog method. Simulation results are presented, including the flow fields, electric field, and thermodynamic parameters of the air plasma in the discharge channel of a high-power induction plasmatron. The results obtained reveal for the first time the structure and parameters of a plasma torch in a large-diameter (200 mm) discharge channel at powers up to 300 kW, providing the axial specific enthalpies at the channel outlet as high as 68 MJ/kg.