On the heat transfer from a permeable sphere in stokes flow

The heat transfer from a permeable sphere in a uniform, low Reynolds number flow is examined. In our analysis we consider the case when conduction is the dominant heat transfer mechanism in the exterior fluid, i.e. small Péclet number, and the case when convection is dominant, i.e. large Péclet number. Thermal boundary conditions at the surface of the permeable sphere are discussed. At small Péclet numbers the heat transfer rate from a permeable sphere is found to differ at leading-order from that found for an impermeable sphere, whereas, for large Péclet numbers permeability has only a weak or second-order effect on the heat transfer rate.