Influence of the Navier boundary wall slip on flow patterns in micro-scale cavity

Abstract

For the behaviors of micro-fluidics in cavity micro-flow, a CFD numerical simulation is adopted to investigate the slip effects on cavity micro-flow. In addition, a new slip model based on the concept of boundary layer thickness was derived theoretically and tested. It's found that boundary wall with the Navier slip condition will change the pattern of cavity micro-flow. In the case of pressure driven cavity micro-flow, the slip wall boundary condition will restrain the growth and development of vortex in the cavity. On the lid-shear-driven cavity micro-flow, slip wall boundary condition could change the position and shape of vortex separation line under cavity, yet a stronger degree slip will promote the morphological changes of vortex. Meanwhile the new slip model is more applicable to step-wall boundary condition, which will reveal the process of slip occurrence.