Numerical study of the relationship between apparent slip length and contact angle by Lattice Boltzmann Method

The apparent slip between solid wall and liquid is studied by using the Lattice Boltzmann Method (LBM) and the Shan-Chen multiphase model in this paper. With a no-slip bounce-back scheme applied to the interface, flow regimes under different wall wettabilities are investigated. Because of the wall wettability, liquid apparent slip is observed. Slip lengths for different wall wettabilities are found to collapse nearly onto a single curve as a function of the static contact angle, and thereby a relationship between apparent slip length and contact angle is suggested. Our results also show that the wall wettability leads to the formation of a low-density layer between solid wall and liquid, which produced apparent slip in the micro-scale.