Enhanced thermal efficiency of PCM-integrated heat sinks: Insights into T-shaped fins and PCM–air Interface morphology

In this study, the melting process of a phase change material (PCM) within a heat sink featuring T-shaped aluminum fins enclosed by a rectangular aluminum casing is numerically investigated. The design includes an interior PCM region overlaid by an air layer, creating a dynamic air–PCM interface—a critical aspect influencing thermal performance. Using the volume of fluid (VOF) model, the air–PCM interface evolution is meticulously tracked, shedding light on its pivotal role in heat transfer mechanisms during the melting process. The focus of this work is the unexplored impact of T-shaped aluminum fin configurations on thermal characteristics. Two geometric parameters were examined: the aspect ratio of the horizontal to vertical lengths of the T-shaped fins and the bottom width–wall height ratio of the aluminum casing. Notably, a fin aspect ratio of 0.67 was found to effectively moderate the increase in system temperature, whereas a casing aspect ratio of 2.29 significantly delayed the increase in temperature. These results highlight the transformative influence of the air–PCM interface morphology in enhancing natural convection and thermal regulation. Properly optimized T-shaped fin structures not only improve heat transfer performance but also extend the temperature control duration, offering significant advantages for PCM-based heat sinks. The findings demonstrate the potential of this design in latent heat thermal energy storage systems requiring advanced thermal stability and efficiency.