A general solution of unsteady Stokes equations is suggested and its completeness is proved. A simple method of solution for the problem of an arbitrary unsteady Stokes ow in the presence of a sphere is discussed. Some physical properties like drag and torque experienced by the sphere are given and compared with some earlier known results.

No abstract

No abstract

Stokes flow of a viscous, incompressible fluid inside a sphere with internal singularities, enclosed by a porous spherical shell, using Darcy's law for the flow in the porous region is discussed. The formulae for drag and torque are found by deriving the corresponding Faxen's laws. It is found that torque does not depend on the thickness of the spherical shell.Mathematics Subject Classification (1991). 76D07.

A general method to discuss the potential flow past two intersecting circles is presented. This is done by introducing two operators L and M, which generate a group G. A procedure called closure is introduced, which determines the order of the group and the angles of intersection of the two circles.