Evolution of tails of velocity distributions for gas mixtures in the front of a shock wave and influence of nonequilibrium on reaction $\rm H_2$ with $\rm O_2$

Translational nonequilibrium of gases in the front of a shock wave was studied, mainly the behaviour of tails of relative velocity distributions of pairs of molecules. The Monte Carlo method of unstationary statistical simulation with constant weighting factors was used. Increase of a number of model particles permitted to study evolution of tails of distributions of pairs of particles in the field of higher relative velocities. And qualitative new features of behaviour of tails of distribution of twocomponent gas were discovered. Results of modelling of mixtures He with small additives $\rm O_2$ and Xe have given additional arguments of possibility of influence of translational nonequilibrium on reaction $\rm H_2$ with $\rm O_2$.