Simulation of melting of a nano-enhanced phase change material (NePCM) in a square cavity with two heat source–sink pairs

Melting of a NePCM in a square cavity with different arrangements of two heat source–sink pairs flush-mounted on the vertical sidewalls is investigated numerically. The governing equations were solved on a non-uniform mesh using a pressure-based finite volume method with an enthalpy porosity technique to trace the solid–liquid interface. Four different cases are studied: Case I where the sources and sinks are separately placed on two vertical sidewalls; Case II where the sources and sinks are alternately placed on two vertical sidewalls; Case III where the sources are placed below the sinks on the vertical sidewalls; and Case IV where the sources are placed above the sinks on the vertical sidewalls. It was found that, Case II has the highest liquid fraction and Case IV possesses the lowest liquid fraction at the final stages of the melting process. In addition, the impacts of the nanoparticle loading are analyzed. In all the cases studied, the volumetric concentration of nanoparticles of 2% would result in the highest melting rate.