The extended finite element method for rigid particles in Stokes flow

A new method For the simulation of particulate flows, based on the extended finite element method (X-FEM), is described. In this method, the particle surfaces need not conform to the finite element boundaries, so that moving particles can be simulated without remeshing. The near field form of the fl uid now about each particle is built into the finite element basis using a partition of unity enrichment, allowing the simple enforcement of boundary conditions and improved accuracy over other methods on a coarse mesh. We pr esent a weak form of the equations of motion useful for the simulation of f reely moving particles, and solve example problems for particles with presc ribed and unknown velocities. Copyright (C) 2001 John Wiley & Sons, Ltd.