MHD and radiative convection in a fin-assisted NEPCM-filled enclosure under thermal and particle concentration gradients: Implications for energy storage and cooling
Shafqat Hussain, J. Prakash, Bander Almutairi, Katta Ramesh
Abstract
This study investigates heat transfer dynamics in a square enclosure under the influence of a periodic magnetic field and thermal radiation, incorporating two thin fins attached to the horizontal walls at specific distances from the vertical walls. The system is modeled for steady, laminar, incompressible, and Newtonian flow conditions, utilizing a working fluid composed of nano-encapsulated phase change materials (NEPCMs) with a nonadecane core and polyurethane shell. Numerical simulations are conducted using the Galerkin-based finite element method (FEM). Prior to simulations, the developed FEM code is validated against available experimental and numerical data to ensure accuracy. Key findings show that higher Rayleigh numbers improve convective heat transfer and temperature uniformity, while buoyancy ratio and fin positioning notably affect flow and concentration patterns. Specifically, increasing the Hartmann number from 0 to 100 resulted in approximately 39% and 46% decreases in the average Nusselt and Sherwood numbers at higher buoyancy ratio, respectively, indicating that a stronger magnetic field significantly suppressed both heat and mass transfer. At higher buoyancy ratio, increasing the Lewis number from 1 to 10 caused a 54% decrease in the average Nusselt number and nearly a 96% increase in the average Sherwood number, with negligible impact on fluid motion. Furthermore, increasing the fin distance from 0.1 to 0.9 at high Rayleigh number leads to an increase in the average Nusselt number by about 74% and a decrease in the average Sherwood number by 14%. These insights advance understanding of heat transfer in NEPCM-based systems, with applications in advanced cooling and energy storage.