Flow of elastic and viscoelastic spheres in tubes

The flow of deformable particles suspended in a viscous fluid through rigid tubes was considered for: (1) the steady motion of closely-fitting elastic incompressible spheres through cylindrical tubes and (2) unsteady flow of closely-fitting incompressible viscoelastic spheres through taper tubes. This study was originally motivated by an interest in the flow of white cells in narrow capillary blood vessels. However, the theory may be applicable also in some other systems involving particle-fluid interactions, such as the motion of red blood cells in narrow capillaries and transport of encapsulated matter in pipelines. In such cases, the present model may serve as a qualitative guide to the nature of results to be expected.