A computational analysis of heat transport irreversibility phenomenon in a magnetized porous channel
A computational analysis of heat transport irreversibility phenomenon in a magnetized porous channel
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DOI：
10.1108/hff-07-2020-0418
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发表时间：
2020-12-23
影响因子：
4.2
通讯作者：
Ramesh, K.
中科院分区：
文献类型：
--
作者：
Marzougui, Souad;Bouabid, M.;Ramesh, K.
目的研究平行平板的Dirichlet条件下的温度问题。本文采用Boussinesq近似下的广义Brinkman扩展Darcy模型，并利用COMSOL多物理场计算控制方程。设计/方法/途径在本研究中，应用热力学不可逆原理研究了通道内的非定常Poiquille-Rayleigh-Benard（PRB）混合对流结果表明，在均匀横向磁场的作用下，流体的哈特曼数（Ha），达西数（Da），Brinkman数（Br）和孔隙度（Br），以图形方式表示和讨论。温度和速度分布的数值结果，熵产生的变化和流线的等值线图，作为上述控制参数的函数。基于广义Brinkman-扩展Darcy公式，该公式允许在固体壁面上满足无滑移边界条件，发现所考虑的控制参数对流场和熵产有显著的影响。结果表明，流动趋于稳定的四个不同的区域，这强烈地依赖于哈特曼和达西数的变化。局部热力学不可逆性更局限于附近的活跃的顶部和底部的水平壁的通道时，增加Da和减少哈特曼数。还发现布林克曼数变化对熵产生有很大影响。原创性/价值在本工作中，我们正在研究横向施加的外部磁流体动力学对不可压缩、牛顿、粘性的非稳定层流PRB流的熵产生的影响。导电二元气体混合物流体在两个水平加热板的多孔通道中流动。得到了液体速度、温度分布、传热率和熵产率的数值解，并绘制成图形。
PurposeThe purpose of this paper is to evaluate the temperature, the Dirichlet conditions have been considered to the parallel horizontal plates. The model of generalized Brinkman-extended Darcy with the Boussinesq approximation is considered and the governing equations are computed by COMSOL multiphysics.Design/methodology/approachIn the current study, the thermodynamic irreversible principle is applied to study the unsteady Poiseuille-Rayleigh-Benard (PRB) mixed convection in a channel (aspect ratio A = 5), with the effect of a uniform transverse magnetic field.FindingsThe effects of various flow parameters on the fluid flow, Hartmann number (Ha), Darcy number (Da), Brinkman number (Br) and porosity (epsilon), are presented graphically and discussed. Numerical results for temperature and velocity profiles, entropy generation variations and contour maps of streamlines, are presented as functions of the governing parameter mentioned above. Basing on the generalized Brinkman-extended Darcy formulation, which allows the satisfaction of the no-slip boundary condition on a solid wall, it is found that the flow field and then entropy generation is notably influenced by the considering control parameters. The results demonstrate that the flow tends toward the steady-state with four various regimes, which strongly depends on the Hartman and Darcy numbers variations. Local thermodynamic irreversibilities are more confined near the active top and bottom horizontal walls of the channel when increasing the Da and decreasing the Hartmann number. Entropy generation is also found to be considerably affected by Brinkman number variation.Originality/valueIn the present work, we are presenting our investigations on the influence of a transverse applied external magnetohydrodynamic on entropy generation at the unsteady laminar PRB flow of an incompressible, Newtonian, viscous electrically conducting binary gas mixture fluid in porous channel of two horizontal heated plates. The numerical solutions for the liquid velocity, the temperature distribution and the rates of heat transport and entropy generation are obtained and are plotted graphically.