Comparisons between Monte Carlo methods and Navier-Stokes equations for re-entry flows

Abstract

A detailed comparison is made between Navier-Stokes and direct stimulation Monte Carlo calculations for flows near the continuum limit to assess the accuracy of the continuum equations in this regime. Meaningful comparisons require the use of similar physical models. This necessitates the inclusion of a separate rotational energy equation and use of slip boundary conditions. Inclusion of slip boundary conditions resulted in improved agreement between surface properties. Moreover, good agreement was obtained for the various temperatures in the nonequilibrium portion of the flowfield that does not contain the shock region. Departures are noted in the shock region and in regions where thermal diffusion effects are important. 21 refs.