Effects of wall conditions on flow field in a circular micro-channel

Effects of a gas-surface interaction model, the Cercignani-Lampise-Lord model, on primary fluid properties in a circular micro-channel are investigated in this paper. The tangential momentum accommodation coefficient (TMAC) has a significant influence on the flow field in the micro-channel. However, the variation of the flow field with the normal momentum accommodation coefficient is not as significant as that with the TMAC. The fundamental mechanism behind the change of flow field is revealed. Moreover, it is found that the effect of the wall roughness on the flow field is much greater than that of the wall material. When the wall roughness varies, the mass flux of the ring section region between the half radius and the radius changes a lot while the rest remains unchanged. However, the heat flux over the cross section remains almost unchanged with the variation of the wall material when the wall is rough.