OpenMP + MPI parallel implementation of a numerical method for solving a kinetic equation

A two-level OpenMP + MPI parallel implementation is used to numerically solve a model kinetic equation for problems with complex three-dimensional geometry. The scalability and robustness of the method are demonstrated by computing the classical gas flow through a circular pipe of finite length and the flow past a reentry vehicle model. It is shown that the two-level model significantly speeds up the computations and improves the scalability of the method.