The Effects of Surface Roughness on the Gas Flow in Microchannels
Chen Bingyan,Yao Zhaohui,He Feng,Ding Yingtao
(Dept. of Engineering Mechanics, Tsinghua Univ., 100084, Beijing)

Abstract: Numerical simulations are conducted to investigate the effects of surface roughness on flow characteristics of gas through microchannels by introducing a surface roughness viscosity. Using the modified surface rough ness viscosity model, an excellent agreement between the numerical results and the experimental data is found. The computational results indicate that surface roughness has little influence on pressure, density and temperature of the flow field. But its effect on velocity of the flow field is pronounced. The velocity of the gas flow and the velocity gradient near the wall is decreased. Therefore the mass flow rate through the microchannels is also decreased. The effects of surface roughness on the gas flow in microchannels should not be neglected.
Keywords: surface roughness, microchannel, flow characteristics.