Interaction of two spherical particles rotating in a micropolar fluid

The steady-state axisymmetric flow of an incompressible micropolar fluid past two spherical particles is considered. The spherical particles are in general of different sizes and are rotating with different angular velocities about the line connecting their centers. Under the Stokes flow approximation, a general solution is constructed using superposition of the basic solutions in two moving spherical coordinate systems based on the centers of the particles. A collocation technique is used to satisfy the boundary conditions on the surfaces of the particles. Numerical results for the normalized couples acting on each particle are obtained with rapid convergence for various values of the employed parameters.