Lattice Boltzmann simulations of apparent slip in hydrophobic microchannels

作     者：Harting, J. Kunert, C. Herrmann, H. J. 

作者机构：Univ Stuttgart Inst Computat Phys D-70569 Stuttgart Germany 

出 版 物：《EUROPHYSICS LETTERS》 (欧洲物理学快报)

年 卷 期：2006年第75卷第2期

页      面：328-334页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

主　　题：FLUID-SOLID INTERFACE BOUNDARY-CONDITION MOLECULAR-DYNAMICS SURFACES FLOWS LIQUIDS EQUATION MODEL 

摘      要：Various experiments have found a boundaryslip in hydrophobic microchannel flows, but a consistent understanding of the results is still lacking. While Molecular Dynamics ( MD) simulations cannot reach the low shear rates and large system sizes of the experiments, it is often impossible to resolve the needed details with macroscopic approaches. We model the interaction between hydrophobic channel walls and a fluid by means of a multi-phase lattice Boltzmann model. Our mesoscopic approach overcomes the limitations of MD simulations and can reach the small flow velocities of known experiments. We reproduce results from experiments at small Knudsen numbers and other simulations, namelyan increase of slip with increasing liquid-solid interactions, the slip being independent of the. ow velocity, and a decreasing slip with increasing bulk pressure. Within our model we develop a semi-analytic approximation of the dependence of the slip on the pressure.