Thermodynamic and Transport Properties for Inductive Plasma Modeling

Abstract

A review is given of models for the thermodynamic and transport properties of inductive plasmas under conditions of local thermodyanimc equilibrium. The thermodynamic properties of individual species are computed using a statistical mechanics formulation based upon the rigid rotator and harmonic oscillator model. Complex cut-off criteria for the electronic levels and anharmonicity corrections are not needed for practical equilibrium calculations. An efficient iterative technique is proposed for the calculation of the equilibrium mixture thermodynamics properties. Through a Schur-complement approach the number of unknowns in the nonlinear system, which determines the equilibrium chemical composition, may be reduced to the number of basic elements. The method is demonstrated for equilibrium air computations. The plasma transport properties are computed with the method of Chapman and Enskog. Accurate formulas for the heavy particle and electron transport properties are discussed. Through a straightforward argument the result of Butler and Brokaw for the reactive thermal conductivity is shown to be valied for ionized equilibrium mixtures. Computed results for the thermodynamic and transport properties of air are compared with numerical and experimental results of other researchers