Coupling of the Wang Chang–Uhlenbeck equations with the multispecies Euler system

After having recalled the basic properties of the Wang Chang–Uhlenbeck equations, we describe a class of relaxation schemes to solve the multispecies Euler system closed with a non-classical state equation, system which is the fluid limit of these kinetic equations. Then, we show how to couple the resolution of the Wang Chang–Uhlenbeck equations with the resolution of this Euler system by using a particular relaxation scheme – namely, a kinetic scheme – which allows to define a natural boundary condition at the kinetic–fluid interface and by using a Marshak condition to take into account the effect of the Knudsen layer in the fluid domain through an asymptotic matching. Finally, we show applications in the field of the Atomic Vapor Laser Isotopic Separation (AVLIS).