A rigorous model reduction for the anisotropic-scattering transport process

Abstract

The mesoscopic particle transport mechanics is bridged to the macroscopic fluid dynamics through the asymptotic theory. The construction of a concise model in the asymptotic regime is a major objective of kinetic theory. In this work, we propose a reduced-order model to bridge the particle transport mechanics and the macroscopic fluid dynamics in the highly scattered regime. A rigorous mathematical derivation and a concise physical interpretation are presented for an anisotropic-scattering transport process with arbitrary order of scattering kernel. The prediction of the theoretical model perfectly agrees with the numerical experiments. A clear picture of the diffusion physics is revealed for the neutral particle transport in the asymptotic optically thick regime.