Melting of NEPCM within a Cylindrical Tube: Numerical Study Using the Lattice Boltzmann Method

Abstract

This article presents a numerical investigation on melting of phase change material (PCM) enhanced by nanoparticles inside a cylindrical tube using the lattice Boltzmann method. Water (ice) and copper particles are chosen as the base fluid (PCM) and nanoparticles, respectively. Results show that the melting rate is the same for all regions of the cylinder for a low Rayleigh number, while it intensifies at the top half of the cylinder for a moderate Rayleigh number. Also, existence of strong unstable flow in the bottom portion of the cylinder at a Rayleigh number of 10⁶ causes the melting rate to keen after a definite time. Nanoparticles have no significant effect on the melting rate at the beginning of melting, where the conduction mode of heat transfer dominates between the hot wall and solid PCM, while full melting of PCM occurs earlier by the increase of solid concentration.