Thermal Evaluation of Heat Sinks as Heat Exchangers

André Issao Sato¹; Carlos Alberto Carrasco Altemani¹

¹ UNICAMP

doi:10.20906/CPS/COB-2015-2039

Resumo

The thermal evaluation of heat sinks is traditionally performed by a convective resistance model in which the cold fluid flow temperature increase through the heat sink is not considered. One alternative that takes this effect into account is to model heat sinks as heat exchangers. In this model, heat sinks are treated as heat exchangers with an infinite thermal capacity of a hot fluid at a temperature equal to that of the heat sink base. For any airflow rate of the cold fluid, the thermal capacity ratio of this heat exchanger is equal to zero. In the present work a numerical investigation was performed to evaluate the average convective heat transfer coefficient for airflow through parallel plates heat sinks with top inlet and side exit. The purpose was to obtain a general correlation for the average Nusselt number in the fins channels of distinct heat sinks as a function of the airflow Reynolds number and dimensionless geometric parameters of the heat sinks. Some results obtained from this work were compared with correlations for the average Nusselt number from the literature and also with experimental data for heat sinks from the literature.

Palavras-chave: heat sink; heat exchanger; impingement flow; plate-fin