Influence of surface characteristics on scattering behavior in Couette flow with heat transfer

Abstract

The Couette flow with heat transfer between two parallel walls for a rarefied argon (Ar) gas is considered to investigate the scattering behavior of the reflected gas molecule at a solid wall surface. Two types of the surface state are taken: a smooth platinum (Pt) surface and the platinum surface which physically adsorbs water (H2O) molecules. The analysis is based on the molecular dynamics (MD) method for the interaction of gas molecules with the wall surface together with the direct simulation Monte-Carlo (DSMC) method for the motion of gas molecule. The accommodation coefficients of momentum and energy are obtained. The flow velocity and temperature distributions between the two walls, and the velocity distribution function of the reflected molecule are also examined. It is found that the speed ratio and the temperature differences between two walls lead to variations of the accommodation coefficients.