Transient magneto-hydrodynamic modeling of inductively coupled plasma discharges

Inductively coupled plasma (ICP) generated by high power inductive discharges offers a large volume of contamination-free plasma for a considerable amount of time for various applications as it does not require electrodes to generate the plasma. However, many literatures involving experimental as well as computational work report complex 3D structures with undulating plasma-cold gas interfaces making the ICP unstable in the torch as well as the jet region which often leads to unsatisfactory application results.

The present work focuses on the computational study of magneto-hydrodynamic instabilities in ICP wind tunnels due to transient electro-magnetic fields and three-dimensional effects(created by non-axisymmetric coil configurations) in order to quantify its stability criteria. The MHD governing equations consists of a set of Navier-Stokes equations which are solved in a cell-centered finite volume flow solver and Maxwell equations which are solved in a mixed finite-element electromagnetic solver. Both sets of equations are coupled via Lorentz forces and Joule heating terms in the momentum and energy equations respectively.

The coupled multi-physics framework can perform simulations for 2D axi-symmetric as well as 3D ICP configurations. Preliminary results are obtained for a steady state 2D-axisymmetric plasma torch configuration. The results have been validated via code-to-code validation with another ICP solver CoolFluid. The future work will focus on performing three-dimensional transient ICP simulations to study the effects of transient electromagnetic field and actual coil configuration on the plasma flowfield.