Approximation of State Equations in Three-Temperature Model for Non-Stationary Flows of Heatconductive Gas

In the case of modeling of nonstationary flows of heat-conductive gas in three-temperature approximation the system of differential equations is completed by state equation for medium components. It is convenient to set them in the form of functions on density and temperature. The condition of thermodynamic equilibrium defines restrictions for these functions. The construction of state equations for partially ionized plasma is considered. Plasma is simulated by definition of function of ion charge in the form of exponential function of density and temperature.