Partially filled metal foam channels for improved thermal–hydraulic performance in forced convection: An experimental investigation

Abstract

In this paper, we report the findings from an experimental investigation aimed at assessing the potential for reducing pumping power penalty in channels partially filled with metal foams while maintaining thermal performance. The thermal–hydraulic performance parameter $J/F^{1/3}$, where $J$ is the Colburn-J factor and $F$ is the friction factor was used to compare the relative performance of foams at various values of blockage fractions ($B$), where $B$ is defined as the ratio of the height of the foam to the height of the channel. The metal foam samples considered were 10 PPI 6101-T6 Aluminum, with porosity of $\sim$ 94%–96%, and B of 1/6, 1/3, 2/3, 5/6, and 1. The Reynolds number (based on the channel hydraulic diameter and inlet velocity) was varied from 1000 to 15,000. A modification was made to all configurations with $B<1$ by attaching an aluminum plate on top, thereby creating a clear separation between the foam-free and the foam-filled flows. The results of our investigation indicate that the plated configurations outperformed their non-plated counterparts in almost all flow scenarios, with B $=$ 1/3 configuration yielding the most optimal performance. We also explored the impact of Pores Per Inch (PPI) for this specific case and found that lower PPI values are preferable. The experimental setup led to significant improvements: thermal–hydraulic efficiency was boosted by 14.5%, pressure drop was reduced by up to 40%, and minimal temperature rise was observed for the case of $B=5/6$. These outcomes highlight the impact of partial foam blockage on enhancing heat transfer and reducing pressure drop, making it a valuable approach for applications requiring efficient thermal management. The insights presented in this study should be of interest to the heat transfer community.