Thermodynamic and Transport Properties of Real Air Plasma in Wide Range of Temperature and Pressure

Air plasma has been widely applied in industrial manufacture. In this paper, both dry and humid air plasmas’ thermodynamic and transport properties are calculated in temperature 300-100000 K and pressure 0.1-100 atm. To build a more precise model of real air plasma, over 70 species are considered for composition. Two different methods, the Gibbs free energy minimization method and the mass action law method, are used to determinate the composition of the air plasma in a different temperature range. For the transport coefficients, the simplified Chapman-Enskog method developed by Devoto has been applied using the most recent collision integrals. It is found that the presence of CO₂ has almost no effect on the properties of air plasma. The influence of H₂O can be ignored except in low pressure air plasma, in which the saturated vapor pressure is relatively high. The results will serve as credible inputs for computational simulation of air plasma.