DSBGK Method to Incorporate the CLL Reflection Model and to Simulate Gas Mixtures

TL;DR

This paper extends the DSBGK simulation method to incorporate the CLL reflection model for polished surfaces and adapts it to efficiently simulate gas mixtures with high density contrasts, relevant for space shuttle applications.

Contribution

The authors develop a DSBGK algorithm implementing the CLL reflection model and extend it to simulate gas mixtures with high density contrasts efficiently.

Findings

Successfully implemented CLL reflection model in DSBGK simulations.

Extended DSBGK to handle gas mixtures with high density contrasts.

Achieved lower memory usage compared to DSMC for similar simulations.

Abstract

Molecular reflections on usual wall surfaces can be statistically described by the Maxwell diffuse reflection model, which has been successfully applied in the DSBGK simulations. We develop the DSBGK algorithm to implement the Cercignani-Lampis-Lord (CLL) reflection model, which is widely applied to polished surfaces and used particularly in modeling space shuttles to predict the heat and force loads exerted by the high-speed flows around the surfaces. We also extend the DSBGK method to simulate gas mixtures and high contrast of number densities of different components can be handled at a cost of memory usage much lower than that needed by the DSMC simulations because the average numbers of simulated molecules of different components per cell can be equal in the DSBGK simulations.