Boundary Layer Growth on a Spinning Sphere

The method of matched asymptotic expansions is employed forinvestigating the growth of the boundary layer on a sphere whichis impulsively started from rest in an incompressible viscousfluid of infinite extent. The sphere is supposed to move alongthe direction of a diameter with constant linear velocity andat the same time to rotate about this diameter with constantangular velocity. It is assumed that the Reynolds number islarge and the time of investigation is short. It is shown thatthe solution of the problem contains terms which are absentfrom the solution based on the boundary layer approximation.These additional terms depend on the Reynolds number, and delayflow separation.