A comprehensive numerical analysis of heat transfer enhancement in NEPCM-water mixtures using oscillating fin and oriented magnetic fields
Mohammed Azeez Alomari, Ahmed M. Hassan, Abdalrahman Alajmi, Abdellatif M. Sadeq, Faris Alqurashi, Mujtaba A. Flayyih
Abstract
This study investigates heat transfer in a square cavity filled with nano-encapsulated phase change material (NEPCM) and water, featuring a flexible oscillating fin and subjected to an inclined magnetic field. Arbitrary Lagrangian-Eulerian (ALE) was used to solve the governing equations. The study includes verifying the effect of the following parameters: Rayleigh number from 10 3 to 10 5 , Hartmann number from 0 to 30, Stefan number from 0.1 to 0.9, NEPCM concentration from 0.01 to 0.04, fusion temperature from 0.1 to 0.9, oscillation amplitude from 0.05 to 0.15, magnetic field angle from 0 o to 90 o . The results showed that heat transfer enhanced by increasing Rayleigh number and NEPCM concentration, with Nusselt number increasing by 82.8 % as Rayleigh number rises from 10 4 to 10 5 . Conversely, increasing Hartmann number suppresses convection, reducing Nusselt by 17 % as Hartmann increases from 5 to 30. An optimal fusion temperature of θ f ≈ 0.5 maximizes heat transfer efficiency. The flexible fin's oscillation amplitude modestly improves heat transfer, while the magnetic field's inclination angle exhibits a non-linear effect with an optimal angle around 45°. These results offer guidance on how to best optimise NEPCM-based thermal management systems for a range of applications.