Scaling limits for the Ruijgrok–Wu model of the Boltzmann equation



The Ruijgrok–Wu model of the kinetic theory of rarefied gases is investigated both in the fluid-dynamic and hydro-dynamic scalings. It is shown that the first limit equation is a first order quasilinear conservation law, whereas the limit equation in the diffusive scaling is the viscous Burgers equation. The main difficulties came from initial layers that we handle here. Copyright © 2001 John Wiley & Sons, Ltd.