Low Reynolds number heat transfer from a sphere in a laminar flow of non-Newtonian fluids

An approximate solution of a steady-state problem of heat transfer from a sphere placed in a laminar stream of an non-Newtonian fluid is obtained for small Reynolds numbers. The problem is solved by the method of matched asymptotic expansions. Expansions for temperature and Nusselt number are obtained. The non-Newtonian parameters modify the terms of sigma-square R-squared in the expansion for Nusselt number. The results of the present work are for R greater than 1 in which Prandtl number is of order unity. It has been concluded that the Nusselt number for viscoelastic fluids may increase or decrease depending on their properties.