Numerical analysis of the Taylor-Vortex flow of a slightly rarefied gas

The axisymmetric Taylor-vortex flow of a rarefied gas between two coaxial circular cylinders, a rotating inner cylinder and a resting outer one, is investigated numerically for small Knudsen numbers on the basis of the compressible Navier-Stokes (CNS) equations and their appropriate slip boundary conditions. The accuracy of the result as an approximate solution to the Boltzmann equation is confirmed by comparing it with the result obtained by the direct simulation Monte Carlo (DSMC) method for Knudsen numbers of the order of 10−2. The flow field for smaller Knudsen numbers (of the order of 10−3) exhibits a boundary-layer like structure near the cylinders. It is shown that, compared with the cylindrical Couette flow, the velocity slip in the circumferential direction is enhanced in the Taylor-vortex flow.