Slip Flow over a Smooth Platinum Surface

The molecular dynamics method for the interaction of gas molecules with a solid wall together with the Monte-Carlo method for the motion of gas molecules are applied to analyze the behavior of a slightly rarefied gas between two walls. The walls consist of platinum molecules, and the gas is taken to be xenon or argon. The Couette flow and the thermal problem for which two walls have different temperatures are considered. The slip and jump coefficients, tangential momentum and energy accommodation coefficients are obtained at the wall whose temperature is 300 K. The tangential momentum accommodation coefficient of argon is as low as 0.19. The distribution functions of the reflected molecules are also obtained, and it is found that the Maxwell-type boundary condition describes well the distribution function of the reflected molecules.