Unsteady heat and/or mass transfer from a fluid sphere in creeping flow

The transient heat and/or mass transfer from a fluid sphere with internal c irculation into a flowing fluid are investigated. The temperature and/or co ncentration inside the sphere are considered uniform. Two cases are studied : the physical mass and/or heat transfer and the mass transfer accompanied by an isothermal, first-order irreversible chemical reaction in the continu ous phase. Steady, creeping flow is assumed around and inside the sphere. T he problem is solved by a finite difference method in the range of paramete rs, 10 less than or equal to Pe less than or equal to 1000, 0.01 less than or equal to H (Phi (h)) less than or equal to 100, 0.1 less than or equal t o Da less than or equal to 1000. The influence of distribution coefficient (H) or volume heat capacity ratio (Phi (h)) on the transfer late and therma l wake phenomenon is analysed. (C) 2001 Elsevier Science Ltd. All rights re served.