Modelling forward vortex flow in a microwave plasma

In this paper, 3D, turbulent fluid models of a CO₂, forward vortex, microwave plasma are presented. The high temperature (3000–7000 K), heterogeneous plasma is modelled as a turbulent heated gas. In the turbulence (RANS) models the heat source is based on experimental observations, and the gas is described as a single species representing the plasma mixture. The model is validated using experimentally measured temperature values from literature, and works well for the investigated pressures, except for downstream values and the maximum temperature for 100 mbar. Agreement of the model with experiment is best in the plasma region, and depends on the shape of the heat source and the choice of turbulent Prandtl number. It is shown that the preferential model is the k–ω RANS model. We conclude that the k–ω model with a gas composition represented by a single species can provide sufficiently accurate temperature profiles for in silico engineering of high temperature CO₂ plasma reactors.