PERFORMANCE ANALYSIS OF ECCENTRIC ANNULAR FINS WITH A VARIABLE BASE TEMPERATURE

Abstract

The paper presents a numerical technique for the determination of the performance of eccentric annular fins with a variable base temperature. The differential equation for heat conduction in the fin has been written in a bipolar coordinate, which facilitates proper imposition of the boundary conditions. The control volume based finite difference method has been adopted to obtain the temperature distribution in the fin. Accuracy of the numerical result has been checked against that obtained from a semianalytical technique for the limiting condition of constant base temperature. Efficiencies of eccentric annular fins have been computed for different parametric variations. It has further been shown that for a nonuniform base temperature distribution, eccentric annular fins may dissipate more heat compared to a concentric fin of the same volume and there exists an optimum value of eccentricity that maximizes the rate of heat transfer. Therefore a saving in fin material may be achieved using eccentric annular fins if there exists a variation of base temperature.