This paper numerically investigates the heat transfer performance of thermally developing non-Darcy forced convection in a fluid-saturated porous medium tube under asymmetric entrance temperature boundary conditions. The Brinkman flow model and the local thermal non-equilibrium (LTNE) model are employed to establish the mathematical model of the studied problem to predict the forced convective heat transfer. Then, the mathematical model is numerically solved using COMSOL Multiphysics. Consequently, the fluid velocity field, the solid temperature field, the fluid temperature field and the Nusselt number are obtained. Moreover, the dependences of the Nusselt number on some key parameters are analyzed in detail. The results show that the distribution characteristics of the Nusselt number are strongly dependent on the form of the entrance temperature function. Meanwhile, it is found that the Nusselt number increases first and then tends to approach an asymptotic value with the increase in the Darcy number and the Biot number. The Nusselt number monotonously increases with increasing the Péclet number. On the contrary, the Nusselt number decreases first and then tends to be an asymptotic value owing to the increase in the thermal conductivity ratio and the viscosity ratio. This study is of benefit to provide in-depth insights into the non-Darcy forced convective heat transfer in porous tubes with asymmetric inlet temperature under LTNE condition.

中文翻译：

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LTNE条件下入口温度不对称多孔圆管热发展非达西强迫对流数值研究

本文数值研究了非对称入口温度边界条件下流体饱和多孔介质管中热发展非达西强制对流的传热性能。采用Brinkman 流动模型和局部热非平衡(LTNE) 模型建立所研究问题的数学模型来预测强制对流传热。然后，使用 COMSOL Multiphysics 对数学模型进行数值求解。从而得到流体速度场、固体温度场、流体温度场和努塞尔数。此外，详细分析了努塞尔数对一些关键参数的依赖性。结果表明，努塞尔数的分布特征强烈依赖于入口温度函数的形式。同时发现，随着达西数和毕奥数的增加，努塞尔数先增加后趋于渐近值。Nusselt 数随着 Péclet 数的增加而单调增加。相反，由于热导率和粘度比的增加，努塞尔数先减小后趋于渐近值。这项研究有助于深入了解 LTNE 条件下入口温度不对称的多孔管中的非达西强制对流传热。发现随着达西数和毕奥数的增加，努塞尔数先增加后趋于渐近值。Nusselt 数随着 Péclet 数的增加而单调增加。相反，由于热导率和粘度比的增加，努塞尔数先减小后趋于渐近值。这项研究有助于深入了解 LTNE 条件下入口温度不对称的多孔管中的非达西强制对流传热。发现随着达西数和毕奥数的增加，努塞尔数先增加后趋于渐近值。Nusselt 数随着 Péclet 数的增加而单调增加。相反，由于热导率和粘度比的增加，努塞尔数先减小后趋于渐近值。这项研究有助于深入了解 LTNE 条件下入口温度不对称的多孔管中的非达西强制对流传热。由于热导率和粘度比的增加，努塞尔数先减小后趋于渐近值。这项研究有助于深入了解 LTNE 条件下入口温度不对称的多孔管中的非达西强制对流传热。由于热导率和粘度比的增加，努塞尔数先减小后趋于渐近值。这项研究有助于深入了解 LTNE 条件下入口温度不对称的多孔管中的非达西强制对流传热。