Thermal Modeling and Analysis of Metal Foam Heat Sink with Thermal Equilibrium and Non-Equilibrium Models

摘要

In the present study, the thermal performance of metal foam heat sink was numerically investigated by adopting the local thermal non-equilibrium (LTNE) model and local thermal equilibrium (LTE) model. Temperature field distributions and temperature difference field distributions of solid and fluid phases were presented. Detailed thermal performance comparisons based on the LTE and LTNE models were evaluated by considering the effects of the relevant metal foam morphological and channel geometrical parameters. Results indicate that a distinct temperature difference exists between the solid and fluid phases when the LTNE effect is pronounced. The average Nusselt numbers predicted by both the LTE and LTNE models are approaching with the increase of porosity, pore density, Reynolds number, large thermal conductivity ratio, and large aspect ratio. This is attributed to the significant reduction of the interstitial convective thermal resistance between the solid and fluid phases, as a result, the LTE model can replace the LTNE model for thermal modeling in these conditions. In addition, the overall thermal performance assessment of metal foam heat sink is compared with the non-porous heat sink, and it shows that the thermal performance factor of metal foam heat sink is approximately two times of the non-porous heat sink.