Effects of boundary slip and apparent viscosity on the stability of microchannel flow

The effects of boundary slip, apparent viscosity and their combined modification on the mean velocity and stability of plane microchannel flow are investigated. Two kinds of microchannel are considered in this approach. One is the channel wall made of the same material. The other is the channel wall made of different materials. The boundary slip is determined by Navier slip condition. Apparent viscosity is considered by a model, where the effects of channel wall on liquid viscosity are assumed as a function of the distance from channel wall. Numerical results show that the boundary slip always stabilizes the flow and the apparent viscosity destabilizes the flow. It also shows that the effects of boundary slip are reduced sharply by considering the apparent viscosity modification. It means that the interaction between the close-wall molecules of liquid and solid wall is strong enough to resist boundary slip.