Heat transfer modulation in Phase Change Materials via fin insertion

TL;DR

This study uses numerical simulations to optimize fin geometries in PCM cells, significantly improving heat transfer and reducing melting time by analyzing effects of fin size, buoyancy, and heat properties.

Contribution

It provides a systematic analysis of how fin dimensions and physical parameters influence heat transfer in PCM cells, guiding design optimization.

Findings

Fin insertion enhances heat transfer and convection.

Optimized fin geometries reduce melting time.

Insights for manufacturing and operating conditions.

Abstract

We leverage a large set of numerical simulations to study optimized geometrical configurations for Phase Change Materials (PCMs) cells. We consider a PCM cell as a square enclosure with a solid substance that undergoes melting under the effect of a heat source from one side and under the effects of buoyancy forces. Moreover, an additional source fin with prescribed length $l$ and height $h$ protrudes into the cell perpendicularly from the heat source. The fin prompts enhanced heat transfer and convection within the PCM cell, thus shortening (in comparison to a finless cell) the melting time $t_m$ needed for all the PCM material to melt and transit from the solid to the liquid phase. This improvement is systematically studied as a function of the fin geometrical details ($l$, $h$), as well as the Rayleigh number $\operatorname{Ra}$ -- encoding the importance of buoyancy forces with respect to diffusion/dissipation effects -- and the Stefan number $\operatorname{St}$ -- encoding the importance of sensible heat with respect to latent heat. Overall, our systematic study in terms of the free parameters $l$, $h$, $\operatorname{Ra}$ and $\operatorname{St}$ offers inspiring insights to optimize the structure of a PCM cell during its manufacturing process and suggests optimal operating conditions for such geometrical configurations.