An extended Navier-Stokes formulation for gas flows in the Knudsen layer near a wall

Gas flows in the Knudsen layer adjacent to a solid wall cannot be described by the classical Navier-Stokes constitution in general, and high-order models such as the Burnett and super-Burnett models encounter many difficulties in practical applications. In the present work we propose an extended Navier-Stokes constitution in which the effect of the collisions between the gas molecules and bounded walls is incorporated. With this model, it is found that the flow behaviors in the Knudsen layer can be effectively captured.