Transient Analysis and Optimization of Annular Elliptical Fins with Mixed Boundary Condition

Fins increase the rate of heat dissipation to surrounding atmosphere. Different geometries of the fins show different heat transfer rate. This paper gives comparative heat transfer synopsis between circular annular fins and elliptical annular fins in transient state. Heat dissipation for elliptical fins with different aspect ratios have been modelled and simulated. Energy balance for the fin is done taking into consideration all three modes i.e., conduction, convection and radiation. Transient analysis for 200sec is done for both circular and elliptical annular fins. Results show that elliptical fins give high temperature gradient with time when compared to former. As the aspect ratio of the elliptical fins increases the slope of temperature gradient with respect to dimensionless time i.e., Fourier number goes on decreasing. The temperature gradient for elliptical annular fin with aspect ratio 0.1 and a circular annular fin whose aspect ratio is 1 are observed to be same during mathematical modelling. Effectiveness of elliptical annular fins with varying aspect ratio was plotted with Fourier number. When compared to circular annular fins later one show high effectiveness enhancement with decrease in aspect ratio. Efficiency of the fins with different aspect ratio were compared and observed that the maximum efficiency value for lower aspect ratios is high