Análise Térmica do Desempenho de Aletas com Propriedades Variáveis

Abstract

Fins are devices designed to enhance heat transfer, increasing the efficiency of thermal exchange between a solid and its surrounding medium. Given their broad applicability in engineering and related fields, it is essential to understand the thermal behavior of these structures in order to optimize their performance under various operating conditions. In this context, the present work aimed to perform a thermal analysis of the performance of a semi-spherical fin (a geometry that has been little explored in the literature) considering internal heat generation, convection, conduction, and radiation, as well as temperature-dependent properties. The influence of the main dimensionless model parameters on temperature and efficiency profiles was analyzed. To simulate the temperature profiles, a combination of the Finite Difference Method and Newton’s Method was proposed. The results obtained were compared with those found using the Collocation Method. As expected, as the number of discretization points increases, the sum of the absolute error decreases. However, numerical saturation is observed; that is, for a number of points greater than 250, there is no significant gain in accuracy, only an increase in computational cost. Regarding the sensitivity analysis, the results highlighted the importance of each type of energy contribution, with particular emphasis on thermal radiation, as this mechanism can significantly affect both temperature profiles and fin efficiency. It was observed that radiationrelated parameters enhance heat dissipation, but at high values, they may reduce efficiency. In contrast, for parameters related to internal heat generation, it was found that at high levels, the fin efficiency tends to reach its maximum value.