Purpose

Thermo-magnetic convective flow analysis under the impact of thermal radiation for heat and entropy generation phenomena is an active research field for understanding the efficiency of thermodynamic systems in various engineering sectors. This study aims to examine the characteristics of convective heat transport and entropy generation within an inverted T-shaped porous enclosure saturated with a hybrid nanofluid under the influence of thermal radiation and magnetic field.

Design/methodology/approach

The mathematical model incorporates the Darcy-Forchheimer-Brinkmann model and considers thermal radiation in the energy balance equation. The complete mathematical model has been numerically simulated through the penalty finite element approach at varying values of flow parameters, such as Rayleigh number (Ra), Hartmann number (Ha), Darcy number (Da), radiation parameter (Rd) and porosity value (e). Furthermore, the graphical results for energy variation have been monitored through the energy-flux vector, whereas the entropy generation along with its individual components, namely, entropy generation due to heat transfer, fluid friction and magnetic field, are also presented. Furthermore, the results of the Bejan number for each component are also discussed in detail. Additionally, the concept of ecological coefficient of performance (ECOP) has also been included to analyse the thermal efficiency of the model.

Findings

The graphical analysis of results indicates that higher values of Ra, Da, e and Rd enhance the convective heat transport and entropy generation phenomena more rapidly. However, increasing Ha values have a detrimental effect due to the increasing impact of magnetic forces. Furthermore, the ECOP result suggests that the rising value of Da, e and Rd at smaller Ra show a maximum thermal efficiency of the mathematical model, which further declines as the Ra increases. Conversely, the thermal efficiency of the model improves with increasing Ha value, showing an opposite trend in ECOP.

Practical implications

Such complex porous enclosures have practical applications in engineering and science, including areas like solar power collectors, heat exchangers and electronic equipment. Furthermore, the present study of entropy generation would play a vital role in optimizing system performance, improving energy efficiency and promoting sustainable engineering practices during the natural convection process.

Originality/value

To the best of the authors’ knowledge, this study is the first ever attempted detailed investigation of heat transfer and entropy generation phenomena flow parameter ranges in an inverted T-shaped porous enclosure under a uniform magnetic field and thermal radiation.

中文翻译：

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热辐射下倒T形多孔外壳内热磁对流熵产生的数值模拟

目的

热辐射影响下的热和熵产生现象的热磁对流分析是了解各个工程领域热力学系统效率的活跃研究领域。本研究旨在研究在热辐射和磁场的影响下，充满混合纳米流体的倒T形多孔外壳内的对流热传输和熵产生的特性。

设计/方法论/途径

该数学模型结合了 Darcy-Forchheimer-Brinkmann 模型，并在能量平衡方程中考虑了热辐射。通过惩罚有限元方法在不同的流动参数值下对完整的数学模型进行了数值模拟，例如瑞利数（Ra）、哈特曼数（Ha）、达西数（Da）、辐射参数（Rd）和孔隙度值（e）。此外，通过能量通量矢量监测能量变化的图形结果，同时还呈现了熵的产生及其各个组成部分，即由于传热、流体摩擦和磁场而产生的熵。此外，还详细讨论了每个组件的 Bejan 数结果。此外，还引入了生态性能系数（ ECOP ）的概念来分析模型的热效率。

发现

结果的图形分析表明，Ra、Da、e和Rd的值越高，对流热传输和熵产生现象的增强就越快。然而，由于磁力影响的增加，增加 Ha 值会产生不利影响。此外，ECOP结果表明，当Ra较小时，Da、e和Rd的值上升，显示出数学模型的最大热效率，随着Ra的增加，热效率进一步下降。相反，模型的热效率随着 Ha 值的增加而提高，ECOP呈现相反的趋势。

实际影响

这种复杂的多孔外壳在工程和科学领域具有实际应用，包括太阳能集热器、热交换器和电子设备等领域。此外，目前对熵产生的研究将在自然对流过程中优化系统性能、提高能源效率和促进可持续工程实践方面发挥至关重要的作用。

原创性/价值

据作者所知，这项研究是首次尝试详细研究均匀磁场和热辐射下倒T形多孔外壳中的传热和熵产生现象的流动参数范围。