Mass and heat transfer from fluid spheres at low Reynolds numbers

The transfer of heat and mass from a viscous sphere in a fluid of different viscosity is examined in this paper. A Stokesian velocity field is assumed to have been developed inside and around the sphere. The corresponding tra nsport equations are solved by a numerical method. Results are obtained for the case of mass transport from the sphere, which may also be applied to h eat transfer processes. It was observed that the mass transfer from a fluid sphere is in general higher than that from a solid sphere as a result of t he internal circulation. A working correlation for the Sherwood number in t erms of the Peclet number and the viscosity ratio has also been derived fro m the numerical results. (C) 2000 Elsevier Science S.A. All rights reserved .