Abstract
Numerical simulations of RF argon-oxygen and argon-nitrogen thermal plasmas under atmospheric pressure were performed. Two-dimensional continuity, momentum, energy and species equations were solved simultaneously with the electromagnetic equations by using the SIMPLER algorithm. Dissociation and recombination rates of oxygen or nitrogen in the plasmas were taken into account in the numerical model. Distributions of the plasma enthalpy and concentration were measured with a water-cooled probe. The numerical results were in good agreement with the experimental ones.
The argon-oxygen plasma has a strong recirculating eddy. O2 is dissociated completely downstream from the eddy except near the tube wall. In the argon-nitrogen plasma, the mass fraction of N2 is significant even in the high-temperature region.