Titarev

The paper contains a review of the recent developments of a three-dimensional computational code "Nesvetay-3D" for modelling rarefied gas flows. The code solves the Boltzmann kinetic equation with various model collision integrals using an implicit finite-volume scheme of Godunov type.  Arbitraryunstructured spatial meshes can be used so that flows over arbitrary geometrical shapes can be computed, including those of. Large-scale computations can be run on hundreds of CPU cores using MPI. Performance and robustness of the numerical scheme and computer code are demonstrated on a number of examples, including gas flows into vacuum through micropipes and external flows over re-entry craftsat high altitude.