• Magnetohydrodynamics (MHD);
  • Two-dimensional axisymmetric model;
  • direct-coupled model (DCM);
  • process torch;
  • Radio-frequency (RF);
  • magnetic potential and fluid flow


The paper aims to clarify the modelling results concerning the heat transfer and fluid flow in a radio-frequency plasma torch with argon at atmospheric pressure. Fluid numerical simulation requires the coupling of magnetohydrodynamics (MHD) and thermal phenomena. This model combines Navier–Stokes equations with the Maxwell's equations for compressible fluid and electromagnetic phenomena successively. A numerical formulation based on the finite element method is used. In this study, fluid flow and temperature equations are simultaneously solved (direct method, instead of using the indirect method) using a finite elements method (FEM) for optically thin argon plasmas under the assumptions of local thermodynamic equilibrium (LTE) and laminar flow. Appropriate boundary conditions are given, and nonlinear parameters such as the thermal and electrical conductivity of the gas and input power used in the simulation are detailed. We have found that the source of power is located on the torch wall in this type of inductive discharge. The center can be heated by conduction and convection via electromagnetic phenomena (power loss and Lorentz force). (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)