Direct simulation methods for low-speed micro-channel flows

Large statistical scatter and effective pressure boundaryconditionsare two critical problems in the computation ofmicrochannel owswith thedirect simulationMonteCarlo (DSMC)method.To address these issues, an extension of theDSMC-IP (informationpreservation) coupledmethod is developed from the one-dimensionalcase to the twodimensional case for microchannel  ow. Simulation results in a microchannel  ow from DSMC, IP, and numerical and analytical solutions to the Navier–Stokes equations are compared. The DSMC-IP coupledmethod successfully reduces the large statistical scatter usually obtained with DSMC in such low-speed  ow systems. It also provides a suitable implementation of pressure boundary conditions.