Computational study on effect of enclosure shapes on melting characteristics of phase change material around a heated cylinder

Abstract

This work investigates the melting and heat transfer characteristics from an isothermally heated circular cylinder placed inside twelve differentially shaped enclosures filled with the lauric acid (PCM). Extensive results are reported on streamlines, temperature contours, and rate of melting to delineate the influence of enclosure shape on the melting performance of thermal energy storage (TES) unit. The study is conducted at two different surface temperatures of the heated cylinder, namely, 333.15 K and 343.15 K. The time required to reach the fully melt condition largely depends on the amount of PCM above the heated cylinder and the interaction between the thermal boundary layers at the adiabatic wall and the cylinder surface. Among all shapes considered, the inverted semi-circular enclosure yields the fastest melting. Simple modifications in the geometrical shape of the enclosure are seen to significantly reduce the melting time (by ∼ four times) required to reach the fully melt condition thereby expediting the energy storage process. Thus, such elementary geometrical changes in the TES systems can hugely benefit by reducing the energy losses and yield larger industrial margins. At the end, limited results are also included for the complete melting-solidification cycle for the utilization of the results in a broader spectrum.

Keywords

• Phase change material
• Differently-shaped enclosures
• Circular cylinder
• Buoyancy-induced melting