Cylindrical Couette Flow of Rarefied Gas: Comparison between Navier-Stokes and DSMC Computations

The cylindrical Couette flow of a rarefied gas is studied in the case of two cylinders rotating with different velocities. Velocity, density and temperature profiles are investigated by the Direct Monte Carlo Simulation method and a numerical solution of the Navier-Stokes equations for compressible flow is found. We have obtained numerical results for gas velocity and temperature at the walls for different values of rotation velocities of the cylinders. The gas lags or outstrips in comparison with the walls or it has the elastic rigid body behavior. These results are important for applications in non-planar microfluidic problems. The results obtained by both methods are in a good agreement at the smaller Knudsen number Kn=0.02 and differs notably at the larger Kn=0.1.