J0550205 Drag exerted on a spherical particle immersed in a rarefied gas flow

Abstract

A slow uniform flow of a rarefied gas past a sphere is considered. Its steady behavior is investigated on the basis of the Boltzmann equation and the diffuse reflection boundary condition by a systematic asymptotic analysis for small Mach numbers, in the case where the Knudsen number is of the order of unity. The sets of the linearized Boltzmann equation and its boundary conditions describing the behavior of the gas in the vicinity of the sphere are derived up to the second order of the Mach number. Based on the derived systems, an expression for the drag is obtained, which extends the existing linear formula to the weakly nonlinear case.