Two-dimensional fin performance: Bi (top surface) >= Bi (bottom surface)

Abstract

The purpose of this work is to present an analysis of the performance and optimization of longitudinal rectangular fins, when the heat transfer coefficients at the top (h(+)) and bottom surface (h(-)), which are expressed in terms of their respective Biot numbers, may be unequal. It is shown that, with the introduction of an equivalent semi-thickness, w(eq), and Biot number based on the average heat transfer coefficient, (h) over bar = (h(+) + h(-))/2, the problem is reduced to the standard fin problem with equal heat transfer coefficients at the lateral surfaces, with insulated or non-insulated tip that was analyzed in [1]. (C) 2004 Elsevier Science Ltd.