SOUND-WAVE PROPAGATION IN A RAREFIED-GAS

The problem of sound wave propagation in a rarefied gas is studied by the use of the linearized BGK model and diffuse reflection boundary conditions. The relevant integrodifferental equation and boundary conditions for the half-space are converted to a system of linear integral equations, which is then solved by a straightforward numerical differencing technique. The present results are in better agreement with the experimental results of Meyer and Sessler and Greenspan than the BGK model results of Sirovich and Thurber and Buckner and Ferziger who, respectively, use analytical continuation and an approximate boundary condition. © 1979 American Institute of Physics.