PARTICLE DRAG FORCE IN A PERIODIC CHANNEL: WALL EFFECTS

This paper presents a computation of the drag force of a particle suspended in a periodic micropore channel, aimed at delineating the effects of the pore walls on the Stokes force. We treat the case of a spherical particle suspended in a newtonian fluid-filled tube whose diameter varies periodically, translating along the axis of the tube. The numerical computations, based on the integral equation formulation and coupling the traction and the velocity fields, are performed with a boundary-element method. An adaptive method is introduced to deal with the weak and strong singular integrals appearing in the mathematical formulation. These results allow to obtain an ordinary differential equation of the particle motion for arbitrary particle size.