Exact Non-Local Hydrodynamics Predict Rarefaction Effects

We combine the theory of slow spectral closure for linearized Boltzmann equations with Maxwell’s kinetic boundary conditions to derive non-local hydrodynamics with arbitrary accommodation. Focusing on shear-mode dynamics, we obtain explicit steady state solutions in terms of Fourier integrals and closed-form expressions for the mean flow and the stress. We demonstrate that the exact non-local fluid model correctly predicts several rarefaction effects with accommodation, including the Couette flow and thermal creep in a plane channel.