Heat or mass transfer from a sphere in Stokes flow at low Péclet number

We consider the low Péclet number, Pe ≪ 1 , asymptotic solution for steady-state heat or mass transfer from a sphere immersed in Stokes flow with a Robin boundary condition on its surface, representing Newton cooling or a first-order chemical reaction. The application of Van Dyke’s rule up to terms of O ( Pe 3 ) shows that the O ( Pe 3 log Pe ) terms in the expression for the average Nusselt/Sherwood number are twice those previously derived in the literature. Inclusion of the O ( Pe 3 ) terms is shown to increase the range of validity of the expansion.