Percolation and Reynolds Flow in Elastic Contacts of Isotropic and Anisotropic, Randomly Rough Surfaces

Abstract

In this work, we numerically study the elastic contact between isotropic and anisotropic, rigid, randomly rough surfaces and linearly elastic counterfaces as well as the subsequent Reynolds fow through the gap between the two contacting solids. We fnd the percolation threshold to depend on the fuid fow direction when the Peklenik number indicates anisotropy unless the system size clearly exceeds the roll-of wave length parallel to the easy fow direction. A critical contact area near 0.415 is confrmed. Heuristically corrected efective-medium treatments satisfactorily provide Reynolds fuid fow conductances, e.g., for isotropic roughness, we identify accurate closed-form expressions, which only depend on the mean gap and the relative contact area.