Model for Flow Resistance of a Rare Gas Accounting for Surface Roughness

摘要

The contribution of surface roughness is included in the flow resistance of rare gas flow channels. The statistical properties of the surface are taken into account in the model applying an approximation for the normal distribution function. The model assumes that the flow channel height varies statistically. Both transverse and longitudinal roughness in wide rectangular ducts are discussed. Simple models are given in terms of an effective viscosity that accounts for the gas rarefaction and surface roughness. They can be applied, e.g., in simulating squeezed-film damping problems where accounting for surface roughness is needed.