The impact of different fin configurations and design parameters on the performance of a finned PCM heat sink

This work builds on our recent research on finned phase change material (PCM) heat sinks, where we proposed a novel Gallium based PCM heat sink concept that counter-intuitively incorporated fins detached from the hot sink base instead of being fully attached to it. The detached and fully attached fin configurations studied utilized the same overall fin size and material resources. The attached fin approach offered less outer fin surface area exposed to the ambient surroundings and less PCM capacity compared with the detached fin approach. However, the attached fin approach facilitated a more direct path for the heat dissipation into the ambient surroundings via the fin body. As an extension of the previous work, the present work explores finned heat sinks that combine the advantages of the above two approaches. First, we present results for two limiting baseline cases of the two finning categories: attached fins with lower outer fin surface area and less PCM and detached fins with a larger exposed fin area and more PCM. Next, we study a heat sink case with attached fins tall enough to have a total outer fin surface area equivalent to the outer surface area of the detached fins case but with less PCM content. Subsequently, we consider cases of fully attached fins with the same total outer fin area and the same total PCM capacity as the detached fins baseline case. Here, we achieve the same PCM content in the sink while still having fully attached fins simply by increasing the overall heat sink size to accommodate additional PCM. This is done in two ways: (1) by expanding the heat sink size in the horizontal direction (i.e., increasing the heat sink width) at constant heat sink height, and (2) by expanding the heat sink height at constant heat sink width. In this work, we propose the best way to utilize the resources in terms of used PCM and used fin content in the heat sink space to achieve the ultimate goal of attaining lowest peak temperatures.