Forced Heat and Mass Transfer From a Slightly Deformed Sphere at Small but Finite Peclet Numbers in Stokes Flow

The fundamental problem of heat and mass transfer from a slightly deformed sphere at low but finite Peclet numbers in Stokes flow is solved by a combined regular and singular perturbation method. The deformed sphere is assumed to be axisymmetric and its shape is described by a power series in a small parameter; the correction to the Nusselt number due to the deformation of the sphere is obtained through a regular perturbation with respect to this parameter. On the contrary, the correction to the Nusselt number due to the small Peclet number is derived by applying a singular perturbation method. The analytical solution is derived for the averaged Nusselt number in terms of the Peclet number and the deformation parameter.