Heat and mass transfer of NEPCM in a wavy porous cavity with variable hot and high-concentration zones: A study using ISPH and XGBoost models

This study examines the heat and mass transfer characteristics within a wavy porous cavity filled with nano-enhanced phase change materials (NEPCM), employing the incompressible smoothed particle hydrodynamics (ISPH) and XGBoost models. Key parameters, including the Darcy number ($\mathrm{Da}$) ranging from ${10}^{-2}$ to ${10}^{-5}$, Rayleigh number ($\mathrm{Ra}$) from ${10}^3$ to ${10}^6$, fusion temperature (${\theta }_f$) from 0.05 to 0.9, and Soret and Dufour numbers ($\mathrm{Sr}$ and $\mathrm{Du}$) up to 0.6, were varied to analyze their impact on heat and mass transfer efficiency. Variable high-temperature and high-concentration zones, extending along the X-axis ($L_X$) from 0.5 to 1.5 and the Y-axis ($L_Y$) from 0.4 to 1.6, were found to play a significant role. Simulations reveal that expanding these zones strengthens the velocity field, with $L_X=1.5$ resulting in an approximate 35 % increase in flow speed, while smaller values reduce convective currents by up to 26 %. This expansion also enlarges temperature and concentration distributions within the cavity. However, a wider high-temperature and high-concentration region decreases the heat capacity ratio ($\mathrm{Cr}$), while enhancing concentration gradients by 25 %, underscoring NEPCM's potential for optimized thermal and mass transfer. These findings highlight the effectiveness of NEPCM and tailored wavy geometries in achieving superior thermal management and uniform distributions within cavities, with promising applications in advanced thermal systems. Future work will focus on experimental validation and varied geometrical configurations to further refine and expand the model's applicability.