Singularities at rims in three-dimensional fluid flow

Asymptotic solutions are presented for Stokes flow near circular rims in three-dimensional geometries. Using nonstandard toroidal coordinates, asymptotic analytical expressions are derived for different corner angles. In comparison to the two-dimensional case, an extra critical corner angle value is derived, below which the swirling behaviour of a particle is absent. Illustrations of the motion of a particle near a rim in a three-dimensional fluid flow are given for different corner angles