The Influence of Surface Roughness on Scattering of Free-Molecular Flow by Solid Bodies

The results of theoretical and experimental studies on the interaction of free-molecular gas flow with the rough surface of a solid body are presented. An atomic force microscope was used to define the roughness of flat metal and glass plates, which were used for investigations in the VAT-103 vacuum set up at TsAGI. The roughness parameter allowing the data on the scattering of molecular flows on rough surfaces of various types to be compared was determined based on computations made by the Monte Carlo method. The experimental results on the interaction of molecular flows with models of varying degrees of roughness are presented.