“…where U and V are the velocity components in non-dimensional form, given by (U, V) = ({K /ll')(u, »), In the case of the Darcy flow, on the surface of the sphere we need not impose a condition on the tangential velocity [21]. However, in the case of a point heat source in an infinite medium, the origin, being the seat of the point source, is a singular point for the flow field and hence the singularity in P at the origin must be a minimum [6].…”