Calculation of transport properties of krypton plasma in thermodynamic nonequilibrium

To study the plasma flow and heat transfer process, it is necessary to understand the two-temperature thermodynamics and transport properties of krypton plasma over wide temperature and pressure range. Therefore, assuming chemical equilibrium and using a method of equilibrium constants with a 2T modified Saha law, we calculated the composition of krypton plasma, and calculated transport coefficients by using Chapman-Enskog method which was expanded to higher approximation. Moreover, we computed the variations of viscosity, thermal conductivity, and electrical conductivity of krypton plasma as a function of temperature, pressure and different degree of temperature non-equilibrium. In the computation, the electron temperature ranges from 300 K to 30 000 K, the ratio of electron temperature (T_e) to the heavy particle temperature (T_h) ranges from 1 to 4, and the pressure ranges within 0.01p₀~10p₀ (p₀=101.325 kPa, standard atmospheric pressures). It is shown that the pressure and non-equilibrium parameter (θ=T_e/T_h) significantly affect the values of viscosity, thermal conductivity, and electrical conductivity. With the reduction of pressure and increased degree of thermodynamic nonequilibrium, the viscosity of krypton plasmas decreases. The degree of thermodynamic nonequilibrium significantly affects the peak value of thermal conductivity. In a high-temperature region, the electron translation thermal conductivity is dominant and increases with the increase of pressure, meanwhile, the electrical conductivity also increases with the increase of pressure. The variation of electrical conductivity with pressure is opposite in low-temperature region. Under the condition of local thermodynamic equilibrium, the calculated transport properties of krypton plasma agree well with previously reported data.