Boundary lubrication: Dynamics of squeeze-out

Abstract

The dynamics of the expulsion of the lubrication fluid confined between two surfaces was analyzed using two-dimensional Navier-Stokes equation combined with kinetic Monte Carlo simulations. Instabilities observed in the boundery line of the expelled film produced a rough boundary for all length scales above a critical value and a smooth boundary for shorter lengths. The pressure gradient in the contact area was shown as the reason behind the squeezing out of all but a few trapped islands of liquid.