Scholarlink

<p>This study presents a numerical investigation of hydromagnetic natural convection and entropy generation in a non-Darcy porous enclosure filled with Fe<sub>3</sub>O<sub>4</sub>–Al<sub>2</sub>O<sub>3</sub>/water hybrid nanofluid in the presence of thermal radiation and localized heat source/sink regions. The dimensionless governing equations are solved using a hybrid finite volume method–marker-and-cell (FVM–MAC) computational framework. The effects of Rayleigh number (Ra = 10<sup>3</sup>–10<sup>6</sup>), Hartmann number (Ha = 0–50), Darcy number (Da = 10⁻<sup>5</sup>–10⁻<sup>1</sup>), radiation parameter (Rd = 0–5), heat generation/absorption parameter, and nanoparticle volume fraction on flow structure, heat transfer, and entropy generation are systematically examined. The results show that increasing the Rayleigh number significantly intensifies buoyancy-driven circulation and enhances convective heat transfer, with the average Nusselt number increasing by approximately 68% between Ra = 10<sup>3</sup> and 10<sup>6</sup>. In contrast, increasing the Hartmann number from Ha = 0 to 50 suppresses fluid circulation due to Lorentz force damping, reducing the local Nusselt number by nearly 40%. Higher Darcy numbers enhance porous medium permeability and strengthen convection, while lower Darcy numbers shift the transport mechanism toward conduction-dominated heat transfer. Thermal radiation substantially improves thermal diffusion and increases wall heat transfer rates, whereas internal heat generation weakens temperature gradients and reduces the Nusselt number. Entropy generation analysis indicates that hybrid nanoparticle loading intensifies thermodynamic irreversibility, with total entropy generation increasing by approximately 41% as the nanoparticle volume fraction rises from 1 to 5%. The present study demonstrates that magnetic field regulation, porous medium permeability, and hybrid nanoparticle doping strongly influence thermal transport and entropy production in porous enclosures. The findings provide useful guidance for the thermal optimization of energy systems, electronic cooling technologies, and magnetically controlled thermal management devices.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

MHD natural convection and entropy generation of Fe3O4–Al2O3/water hybrid nanofluid in a non-Darcy porous cavity using an FVM–MAC method

  • 期刊论文

  • 发表日期：

    2026年7月24日

查看全文
  • K. Venkatadri,
  • V. Ramachandra Prasad,
  • Perepi Rajarajeswari,
  • O. Anwar Bég,
  • R. Kodandan,
  • V. Jalaja

摘要

This study presents a numerical investigation of hydromagnetic natural convection and entropy generation in a non-Darcy porous enclosure filled with Fe3O4–Al2O3/water hybrid nanofluid in the presence of thermal radiation and localized heat source/sink regions. The dimensionless governing equations are solved using a hybrid finite volume method–marker-and-cell (FVM–MAC) computational framework. The effects of Rayleigh number (Ra = 103–106), Hartmann number (Ha = 0–50), Darcy number (Da = 10⁻5–10⁻1), radiation parameter (Rd = 0–5), heat generation/absorption parameter, and nanoparticle volume fraction on flow structure, heat transfer, and entropy generation are systematically examined. The results show that increasing the Rayleigh number significantly intensifies buoyancy-driven circulation and enhances convective heat transfer, with the average Nusselt number increasing by approximately 68% between Ra = 103 and 106. In contrast, increasing the Hartmann number from Ha = 0 to 50 suppresses fluid circulation due to Lorentz force damping, reducing the local Nusselt number by nearly 40%. Higher Darcy numbers enhance porous medium permeability and strengthen convection, while lower Darcy numbers shift the transport mechanism toward conduction-dominated heat transfer. Thermal radiation substantially improves thermal diffusion and increases wall heat transfer rates, whereas internal heat generation weakens temperature gradients and reduces the Nusselt number. Entropy generation analysis indicates that hybrid nanoparticle loading intensifies thermodynamic irreversibility, with total entropy generation increasing by approximately 41% as the nanoparticle volume fraction rises from 1 to 5%. The present study demonstrates that magnetic field regulation, porous medium permeability, and hybrid nanoparticle doping strongly influence thermal transport and entropy production in porous enclosures. The findings provide useful guidance for the thermal optimization of energy systems, electronic cooling technologies, and magnetically controlled thermal management devices.