Impact of shape of container on natural convection and melting inside enclosures used for passive cooling of electronic devices

TL;DR

This study numerically investigates how the shape of enclosures filled with phase change material affects natural convection and melting, revealing significant impacts on cooling efficiency for passive electronic device cooling.

Contribution

It introduces a numerical analysis comparing five different enclosure geometries with PCM, highlighting the influence of shape on cooling performance.

Findings

Geometry significantly affects maximum temperature difference.

Vertical shift of enclosure improves cooling efficiency.

Up to 40°C temperature difference observed between designs.

Abstract

The present paper numerically analyzes a passive cooling system using enclosures with different geometries filled with thermal conductivity-enhanced phase change material (PCM). A numerical code is developed using an unstructured finite-volume method and an enthalpy-porosity technique to solve for natural convection coupled to a solid-liquid phase change. Five geometries containing the same volume of PCM are compared while cooling the same surface. The unsteady evolution of the melting front and the velocity and temperature fields is detailed. Other indicators of cooling efficiency are monitored, including the maximum temperature reached at the cooled surface. The computational results show the high impact of varying geometry: a maximum temperature difference as high as 40^{\circ}C is observed between two of the enclosures. The best efficiency is obtained for an enclosure shifted vertically relative to the cooled surface. Other findings and recommendations are made for the design of PCM-filled enclosures.