The Discussion Of Slip Phenomenon And Drag Reduction In Rough Micro-channels

Micro-flow has become the forefront and hot topics of science and engineering fieldsand has been extensively studied in recent years. Although many researchers have studiedthe influence of rough surface on micro-fluid, the results were different, some evencontradictory. So it is necessary to study the mechanism of it in theory, and then explorehow to improve the surface morphology to make an efficient drag reduction inmicro-channels.In this paper, a theoretical study was conducted on this issue supported by thefollowing conclusions:(1) No-slip boundary condition is no longer applicable in the roughsurer-hydrophobic micro-channels, and the rough topography will make the slipphenomenon occur;(2) when the slip boundary condition is introduced, the relation ofDarcy friction and Reynold number will change, and the Poiseuille number of themicro-channels is no longer a constant related to the shape of micro-channels. At the sametime the quantity and pressure drop within the micro-channels will also change, so themicrostructure of the rough surface has played a drag reduction effect on the fluid flow inmicro-channels.