In this paper, we present a stochastic particle algorithm for the simulation of flows of wall-confined gases with diffuse reflection boundary conditions. Based on the theoretical observation that the change in location of the particles consists of a deterministic part and a Wiener process if the time scale is much larger than the relaxation time, a new estimate for the first hitting time at the boundary is obtained. This estimate facilitates the construction of an algorithm with large time steps for wall-confined flows. Numerical simulations verify that the proposed algorithm reproduces the correct boundary behaviour. (C) 2015 Elsevier B.V. All rights reserved.
Jun Zhang was funded partly by the Engineering and Physical Sciences Council (EPSRC) of the UK under grant EP/I011927/1 and partly by the National Natural Science Foundation of China (Grant Nos. 11002147 and 11372325). Simulation results were obtained using the ARCHIE-WeSt High Performance Computer (www.archie-west.ac.uk), under EPSRC grant EP/K000586/1.
[Onskog, Thomas] Stockholm Univ, Dept Math, SE-10691 Stockholm, Sweden; [Zhang, Jun] Univ Strathclyde, Dept Mech & Aerosp Engn, James Weir Fluids Lab, Glasgow G1 1XJ, Lanark, Scotland; [Zhang, Jun] Chinese Acad Sci, Inst Mech, State Key Lab High Temp Gas Dynam, Beijing 100190, Peoples R China