Forced convection heat and mass transfer from a slender particle

We utilize slender body theory along with a reciprocal theorem to predict the convective enhancement in heat and mass transfer from an axisymmetric particle in a Stokes flow that approaches a uniform stream at large distances. The particle can be oriented at an arbitrary angle to the flow. The Péclet number, Pe, based on the particle length is considered to be O(1), in which case the effect of convection is not small on this scale. Specifically, we calculate the ratio Nu(Pe)/Nu(0) through O(1/ln(1/∊)), where Nu is the Nusselt number (i.e., the normalized heat flux from the particle) and ∊ is the (small) ratio of the characteristic thickness to length of the particle. At fixed Pe, the maximum value of Nu occurs for a body whose axis of symmetry is perpendicular to the imposed flow; the minimum value occurs when the axis of symmetry is aligned with the flow.