DSMC Study of Pressure-Driven Slip Flow through Microchannel at Non-Uniform Wall Temperature

Abstract

ABSTRACTThe present study is to investigate the pressure-driven gas flow in microchannel at no-uniform wall temperature. DSMC is employed to generate the flow field details which are then used in analysis of the slip flow characteristics. The major concern is the influences of thermal creep effect on the pressure-driven slip flow. Thermal creep is resulted from tangential wall temperature gradient. In this work, two kinds of thermal boundary condition are considered. One is the linearly varied temperature (LVT) applied to both walls, the other is that has the bottom wall at a thermal condition combined LVT and adiabatic (AD) wall, i.e. LVT-AD-LVT condition. The present DSMC results reveal that the fluid slip is weakened (enhanced) in the case with a negative (positive) wall temperature gradient. Relatively, thermal creep effect on fluid slip over the adiabatic wall is more pronounced in the presence of negative wall temperature gradient. The mass flowrate is a strong function of the wall temperature gradient. However, there is only little difference between the mass flowrates predicted under the two kinds of thermal conditions studied in the present work.