Numerical study of nonlinear heat transfer in longitudinal fins

This work aims to quantify the effects of non-simplified situations on longitudinal fins efficiency. For this purpose a more realistic model, which has been developed here, is based on variable profile and temperature-dependent thermophysical properties in transient two-dimensional fin with internal non-uniform heat generation. An explicit exponential finite-difference method, conditionally stable, is extended in this study for the discretization of the governing equations. The numerical procedure consists in solving series of nodal temperature distribution according to the type of node, in order to reach the steady-state heat exchange. Then, the numerical simulation is used to present the sensitivity of some parameters on efficiency. Numerical results of interest are illustrated for a direct comparison with the traditional solutions. Extensive numerical experiments were conducted and showed that temperature-dependent heat transfer coefficient and generation lead to a significant reduction of fin-efficiency. The simultaneous effects of parameters for this non-linear problem are not negligible. (C) 2001 Editions scientifiques et medicales Elsevier SAS.