Laminar natural convection in internally finned horizontal annuli

An analysis is made of the laminar natural convection in two internally finned horizontal annuli. The governing equations were solved numerically by a control-volume-based finite difference method. Information about the flow patterns and temperature distributions is presented through velocity vectors, streamlines, and isotherm plots. The effects of Rayleigh number and fin height on the Nusselt numbers are presented for two selected fin orientations. Variations of the local Nusselt numbers along the inner cylinder are also presented. In the cases studied, orientations of the internal fins are found to have insignificant effects on the average Nusselt number.