Recommended Collision Integrals for Transport Property Computations Part II: Mars and Venus Entries

A review of the best-available data for calculating a complete set of binary collision integrals for the computation of the mixture transport properties (viscosity, thermal conductivity, ordinary and thermal diffusion) of 17-species weakly ionized CO 2 -N 2 mixtures is presented. The fidelity of the data varies considerably, but most of the atom-atom interactions are derived from ab initio methods that are estimated to be accurate to within 5%. The remaining important interactions between neutral species are estimated to be accurate to within about 30% over the temperature range of interest (300-20,000 K) to Mars and Venus reentry plasmas. Collision integrals for important ion-neutral interactions are computed using a modified Tang-Toennies potential and have an estimated accuracy of ±25%, whereas those between trace species are approximated via the polarization (Langevin) potential model. The accuracy and valid temperature range for electron-neutral interactions vary considerably due to scarcity of the required cross section data.