Modeling of low-speed rarefied gas flows using a combined ES-BGK/DSMC approach

Modeling of low-speed gas flows at moderate Knudsen numbers, where conventional continuum CFD methods are inapplicable and kinetic methods are either inaccurate of prohibitively expensive, presents a significant challenge for computational modeling. In this work, an approach that combines a finite-volume solution of the ES-BGK model kinetic equation and the statistical DSMC method to accurately predict radiometric forces on a vane in large vacuum chamber filled with rarefied gas is presented. The approach in effect combines the accuracy of a statistical solution of the Boltzmann equation with the numerical efficiency of a deterministic solution of simplified model kinetic equations.