Study on Melting of Beeswax Dispersed with Ferro-Nanoparticles Inside a Square Annulus Cavity Under an External Magnetic Field

This paper describes the combined effect nanoparticles volume fraction and magnetic field on melting of Fe3O4–beeswax as nano-enhanced phase change material (NePCM). A differentially heated square annulus cavity is selected in this present computation. There are four sets of thermal boundary conditions which are considered based on temperature difference above the melting point of phase change material (PCM). Enthalpy porosity technique is adopted to study the melting process of PCM. The governing equations with suitable boundary conditions are solved by the finite volume method (FVM)-based commercial software package ANSYS Fluent. A user-defined function (UDF) is written separately for adding Lorentz force source term. The simulations are performed for different controlling parameters like temperature difference (10 ≤ ∆T ≤ 40), volume fraction of nanoparticles (0 ≤ ϕ ≤ 0.02), Hartmann number (0 ≤ Ha ≤ 40). The results are quantified in the form of melt fraction of the NePCM. Finally, it is evaluated that presence of nanoparticles augments melting process at lower temperature difference, but at higher temperature difference, a contradictory observation has been found. Additionally, it is also found that the presence of external magnetic field declines the melt fraction.