EFFECTS OF CHANNEL SCALE ON SLIP LENGTH OF FLOW IN MICRO/NANO-CHANNELS

The concept of slip length, related to surface velocity and shear rate, is often used to analyze the slip surface property for flow in micro or nano-channels. In this study, a hybrid scheme that couples Molecular dynamics simulation (used near the solid boundary to include the surface effect) and a continuum solution (to study the fluid mechanics) is validated and used for the study of slip length behavior in the Couette flow problem. By varying the height of the channel across multiple length scales, we investigate the effect of channel scale on surface slip length. In addition, by changing the velocity of the moving-solid wall, the influence of shear rate on the slip length in a certain ranee of the channel height is studied. The results show that within a certain range of the channel heights, the slip length is size-dependant. This upper bound of the channel height can vary with the shear rate.