CONJUGATE NATURAL-CONVECTION HEAT-TRANSFER IN A VERTICAL ANNULUS WITH INTERNAL CIRCUMFERENTIAL FINS

A numerical investigation is carried out to study natural convection heat transfer in a vertical annular enclosure with circumferential fins mounted on the inner cylinder. Heat is generated within the inner solid cylinder, while the top, the bottom, and the outer walls are exposed to convection. The results show that, even though the presence of fins does not alter the main features of the flow in the large-scale recirculation zone, it reduces the mean temperature of the inner cylinder by a maximum of 9.6% at low Rayleigh numbers. Also, the number and length of fins have a pronounced effect on the mean temperature.