Micro-tribology of flow-induced load on a surface asperity using Lattice Boltzmann method

In this paper flow around a single roughness, known as asperity, is examined using Lattice Boltzman Method. Elliptical asperity cross section is used for this study. Asperity of various aspect ratios, defined as width-over-thickness ratios are studied using two flow conditions. The flow conditions correspond to parallel (Poisuelle) flow and pressure-driven flow. Results show that negative gage pressure occurs under both flow conditions, in the first due to the flow vortices and in the latter due to emergence and growth of boundary layer. Asperity aspect ratio is shown to give rise to the pressure drop potentially leading to cavitation condition.