Multiscale hybrid simulation of fluid flow in nanochannels with wall roughness

The multiscale hybrid simulation of molecular dynamics and finite volume method is carried out to study the liquid Poiseuille flow through a nanochannel with wall roughness. The effects of roughness height, distribution and shape on the velocity in the whole channel and the slip length are investigated. The results show that the increase of the roughness height results in the reductions of the velocity values and the relative slip length near the rough wall. With the increases of the number of rough arrays and the atom numbers of different roughness shapes, the relative slip length will decrease, but it has little effects on the velocity values. In general, the roughness height is the most important parameter among the studied three affectors.