Two-Temperature Thermodynamic and Transport Properties of Hydrogen Plasmas

The knowledge of two-temperature transport coefficients is of interest in the modelling of fluid flow and heat transfer processes in electric propulsion devices. Variations of species mole fraction, number density, specific enthalpy, specific heat at constant pressure, viscosity, electrical conductivity and thermal conductivity as a function of pressure, electron temperature and different degrees of temperature non-equilibrium are calculated for twotemperature hydrogen plasmas. To meet practical needs of modelling study of arcjet and MPD thrusters, pressure included in the calculation ranges from 0.0001 to 1 atmosphere, temperatures range from 300 K to 40000 K, and the ratio of electron temperature (Te) to the heavy species temperature (Th) ranges from 1 to 4. Results obtained for local thermodynamic equilibrium (LTE) under atmospheric pressure agree well with published results obtained for the same conditions. Nomenclature b = impact parameter between interaction of species i and j cp = specific heat at constant pressure Dij = ordinary diffusion coefficient of species i and j Dij = ambipolar diffusion coefficient of species i and j Dij = binary diffusion coefficient of species i and j e = specific internal energy Ea = dissociation potential of hydrogen molecule Es = ionization potential of hydrogen atom gij = degeneracy of ‘j’th electronic excited level of species i relative velocity between species i and j h = Planck constant hT = specific enthalpy i = species i j = species j k = thermal conductivity kB = Boltzmann constant ke,r = reactive thermal conductivity of electrons kh,r = reactive thermal conductivity of heavy species 1 Graduate Student, School of Astronautics, [email protected]. 2 Associate Professor, School of Astronautics, [email protected]. 3 Professor, Electric Propulsion and Plasma Dynamics Laboratory, [email protected].