Computation of the drag force on a rough sphere close to a wall
  We consider the effect of surface roughness on solid-solid contact in a Stokes flow. Various models for the roughness are considered, and a unified methodology is given to derive the corresponding asymptotics of the drag force. In this way, we recover and clarify the various expressions that can be found in the litterature. 
David G\'erard-Varet (IMJ), Matthieu Hillairet (CEREMADE)
math.AP physics.class-ph