New numerical strategy to evaluate the collision integral of the Boltzmann equation

A new scheme for the calculation of the collision integral of the nonlinear Boltzmann kinetic equation is presented, based on a piecewise constant discrete approximation of the distribution function in phase space and corresponding precalculated collision rate coefficients. The computing effort required for evaluation of the fivefold collision integral is significantly reduced by the use of precalculated rate coefficients. The method was combined with the conservative splitting method to solve the Boltzmann equation for a number of test cases to examine the performance of this method and demonstrate its efficiency. 10 refs., 6 figs.