Study of melting of paraffin dispersed with copper nanoparticles in square cavity subjected to external magnetic field

Abstract

The addition of high thermal conductivity nanoparticles in a phase change material (PCM) is an effective way to improve the thermal performance of the latent heat energy storage system. The present work uses paraffin wax as a PCM, and copper (Cu) nanoparticles are added for thermal conductivity enhancement. The thermal performance of the PCM dispersed with Cu nanoparticles in a square cavity during the melting process is numerically investigated. The enthalpy porosity approach is used to capture the melting of the PCM in the enclosure. The effect of orientation of the heated wall of the square cavity and volume fraction of the Cu nanoparticles on the melting rate and energy storage capacity is evaluated. Subsequently, a uniform external magnetic field in the horizontal direction is imposed on the square cavity filled with nano-enhanced PCM. Further, a parametric study on the strength of the magnetic field based on Hartmann number is performed to analyze the heat transfer and fluid flow characteristics of the PCM during the melting process. The melting rate of PCM and the energy storage capacity of nano-enhanced PCM are found maximum at 2% and 0.5% concentration of Cu nanoparticles, respectively. Additionally, with the increase in the strength of the external magnetic field, a decline in the melting rate and energy storage capacity is observed.