ABSTRACT: Ensemble averaging combined with multiple scattering ideas is applied to the
Stokes flow over a stochastic rough surface. The surface roughness is modeled by compact
protrusions on an underlying smooth surface. It is established that the effect of the
roughness on the flow far from the boundary may be represented by replacing the no-slip
condition on the exact boundary by a partial slip condition on the smooth surface. An
approximate analysis is presented for a sparse distribution of arbitrarily-shaped
protrusions and explicit numerical results are given for hemispheres. Analogous
conclusions for the two-dimensional case are obtained. It is shown that in certain cases a
traction force develops on the surface at an angle with the direction of the flow.
J. Fluid Mech. 316, 223-240, 1996
Andrea Prosperetti's Homepage | Publications