Effect of high Hartmann number on thermal performance of SWCNT-Fe3O4 hybrid nanoenhanced PCM in magnetized minichannel

Abstract

Numerical investigations are conducted to investigate the impact of the magnetic field on the molten phase formation and thermal performance of phase change material (PCM) incorporated with hybrid nanoparticles within a three-dimensional vertical channel subjected to differential heating. The PCM, lauric acid, is dispersed using nanoparticle pairings consisting of iron oxide combined with aluminum oxide, titanium dioxide, and single-wall carbon nanotubes. This study focuses on examining the melting characteristics under turbulent conditions, specifically at high Rayleigh (Ra) and Hartmann number (Ha) within the specified range of 106≤Ra≤1010 and 0≤Ha≤1500. The enthalpy-porosity method is being considered for evaluating the phase change characteristics with an in-house code. For Ha of 1500, the melting process influenced by thermal convection was effectively suppressed, leading to significant delays in the melting rates. The melting time and molten fraction of the PCM exhibit a decreasing trend in response to the applied magnetic field, which results in an 82.14% reduction in the heat transfer rate. The SWCNT-Fe3O4 nanoparticle pairs demonstrated superior thermal performance, as the melting fraction and convective heat transfer were increased by 84.03% and 43.83%, respectively. The thermal performance exhibits a decreasing relationship with the Hartmann number, resulting in a 23.87% reduction in the heat transfer of nanoenhanced lauric acid. The accuracy of the present mathematical model is confirmed through validation against experimental benchmark data.

Keywords

• Lauric acid
• Thermal energy storage
• Hartmann number
• Magnetic field
• Hybrid nanoparticles