A high-order hybridizable discontinuous galerkin method for gas kinetic equation

The high-order hybridizable discontinuous Galerkin method is used to find the steady-state solution of the linearized Shakhov kinetic model equations on two-dimensional triangular meshes. The perturbed velocity distribution function and its traces are approximated in the piece- wise polynomial space on the triangular meshes and the mesh skeletons, respectively. By employing a numerical flux that is derived from the first- order upwind scheme and imposing its continuity on the mesh skeletons, global systems for unknown traces are obtained with a few coupled degrees of freedom. The steady-state solution is reached through an implicit iterative scheme. Verification is carried out for a two-dimensional thermal conduction problem. Results show that the higher-order solver is more efficient than the lower-order one. The proposed scheme is ready to extended to simulate the full Boltzmann collision operator.