Transport Properties for the Chemical Oxygen-Iodine Laser

Abstract

Transport models for computing the diffusivity, viscosity, and thermal conductivity of mixtures over a broad range of temperatures of interest to chemical oxygen-iodine lasers are presented. The individual species transport models are based on the corresponding states correlations for the rare gases and several non-or weakly polar polyatomic molecules developed by Mason, Kestin, and coworkers and extended by Paul to treat strongly polar molecules and the Thijsse expression for conductivity. New polynomial extensions for the molecular collision integrals to allow their computation for 0 < T * < -1 are developed. The potential and molecular parameters for the atomic and diatomic halogens are derived from viscosity data if available, estimated using the Tang-Toennies potential model and the Cambi potential parameter correlations, or obtained from the literature as appropriate.Results are compared to both experimental and theoretical data when available, and good agreement is obtained. Binary interaction potential parameters with which to compute the mixture viscosity and conductivity using the Chapman-Enskog theory are presented for 14 species. New approximate mixture rules that use only the pure species properties are also discussed. Parametric representations of the species viscosities and conductivities are provided for temperatures ranging from 50 to 1000 K. NomenclatureA * , B * , C * , E * = collision integral ratios, dimensionless a = effective rigid-core diameters,Å a 0 = Bohr radius, 0.529177Å C = internal contribution to the molar specific heat, erg/mol · K C P = molar specific heat at constant pressure, erg/mol · K C spn = empirical spin-polarization coefficient, dimensionless C V = molar specific heat at constant volume, erg/mol · K C 2n = long-range dispersion coefficients, erg · cm 2n C * 2n = reduced long-range dispersion coefficientsparametric fit coefficients D = binary mass or internal energy diffusion coefficient, cm 2 /s d = number of rotational degrees of freedom, dimensionless F, G, H = symmetric, positive definite matrix describing mixture transport properties f i j , f η , f λ = Kihara binary mass diffusion, viscosity, and conductivity correction factor, dimensionless g = quantum mechanical summation in the rotational exchange corrections, dimensionless h = Planck constant, h/2π , 1.054592 × 10 −27 erg · s I = rotational moment of inertia, g · cm 2 = number of molecular bond and nonbond electrons N E = effective number of electron oscillators N I , N O = number of inner and outer atomic electrons N S = number of species in the gas mixture N T = total number of atomic or molecular electrons P = gas pressure, torr R = universal gas constant, 8.31434 × 10 7 erg/particle · K R a = ath atom position relative to the molecular center of mass,Å r = intermolecular separation,Å r M = intermolecular equilibrium separation,Å r 2 = ratio of the internal to translational heat capacity, 2C int /5R, dimensionless s 2 = ratio of the rotational to translational heat capacity, 2C rot /5R, dimensionless T = gas ...