USING MONTE CARLO WEIGHT SCHEMES FOR WEAKLY IONIZED RAREFIED GAS FLOWS

The description of the procedures of the direct statistical Monte Carlo simulation of weakly ionized flows arising during the flow of returning spacecraft is presented. For ionization and recombination reactions, expressions are given for the model dependence of the probability of reactions on the velocities and energies of the reagents. The dissociative recombination algorithm is presented, the computational efficiency of which is achieved by bypassing the simulation of the interaction of electrons and heavy particles. An approach to the construction of a weight scheme for elastic collisions and chemical reactions is described, which significantly increases the computational efficiency of calculations. An example of using the described numerical models and procedures to study the weakly ionized flow near the return capsule in typical entry conditions of orbiting spacecraft is presented. The calculation results are compared with the data of measurements of plasma parameters in the flight experiment.