TY - JOUR
T1 - An accurate treatment of diffuse reflection boundary conditions for a stochastic particle Fokker-Planck algorithm with large time steps
AU - Önskog, Thomas
AU - Zhang, Jun
PY - 2015/12/15
Y1 - 2015/12/15
N2 - 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.
AB - 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.
KW - boundary conditions
KW - first hitting time
KW - Fokker-Planck equation
KW - Langevin simulation
KW - rarified gas flows
KW - stochastic differential equations
UR - http://www.scopus.com/inward/record.url?scp=84941242089&partnerID=8YFLogxK
UR - http://www.sciencedirect.com/science/article/pii/S0378437115006123
U2 - 10.1016/j.physa.2015.07.003
DO - 10.1016/j.physa.2015.07.003
M3 - Article
AN - SCOPUS:84941242089
SN - 0378-4371
VL - 440
SP - 139
EP - 146
JO - Physica A: Statistical Mechanics and its Applications
JF - Physica A: Statistical Mechanics and its Applications
ER -