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.