Analysis of Reversed Trapezoidal Fins using a 2-D Analytical Method

Hyung Suk Kang

doi:10.13189/ujme.2015.030505

Abstract

This paper presents a two-dimensional analysis of reversed trapezoidal fins with variable fin base thickness. Heat loss from the reversed trapezoidal fin is presented as a function of the fin shape factor, fin base thickness, and fin base height. The relationship between the fin tip length and the convection characteristic number, as well as that between the fin tip length and the fin base height for equal amounts of heat loss are analyzed. In addition, the relationship between the fin base thickness and the fin shape factor for equal amounts of heat loss is presented. One of the results shows that the heat loss decreases linearly with the increase in the fin shape factor.

Highlights

Extended surfaces or fins are well known to be simple and effective means of increasing heat dissipation in many engineering and industrial applications, such as the cooling of combustion engines, electronic equipments, and many kinds of heat exchangers
As the fin base height increases from 0.2 to 0.4, the fin temperature along the fin centerline increases for all three values of Le
The shape of the fin becomes rectangular for ξ =1 and it becomes a reversed trapezoidal fin for which the fin tip height is twice the fin base height in the case of ξ =0

Summary

Introduction

Extended surfaces or fins are well known to be simple and effective means of increasing heat dissipation in many engineering and industrial applications, such as the cooling of combustion engines, electronic equipments, and many kinds of heat exchangers. Moitsheki et al [6] considered a model describing the temperature profile in a longitudinal fin with rectangular, concave, triangular and convex parabolic profiles by using optimal homotopy analysis method while Huang and Chung [7] determined the optimum shapes of partially wet annular fins adhered to a bare tube based on the desired fin efficiency and fin volume with the conjugate gradient method. In all these studies, fin base temperature is given as a constant for the fin base boundary condition. The thermal resistance from the inside wall to the fin base is changed due to a variation in the fin base thickness, and the thermal energy source is varied with a variation in the fin base height

A 2-D Analytic Method

Results and Discussions

Conclusions