Computation of state to state transport coefficients using ab initio potential energy surfaces for the O + O_2 system

摘要

This work presents the quantification of transport coefficients in a state-based framework for non-equilibrium flows encountered in hypersonic re-entry applications. Vibra-tional state-to-state (StS) collisional properties, namely the potentials, scattering angles, transport cross-sections and collision integrals are computed for the O + O_2 system based on the recent set of nine potential energy surfaces (PESs) proposed by Varga et al. The collision integrals are then compared with those obtained from the single Varandas and Pais PES. Averaged collision integrals, based on all nine Varga et al. surfaces are then used to compute state-based transport coefficients - viscosity and thermal conductivity. A chemically frozen, non-equilibrium relaxation, and chemical equilibrium conditions are chosen to study the influence of vibrational state of O_2 on transport properties. The vibra-tional excitation of the molecule was found to affect the viscosity and thermal conductivity in all three cases considered.