Entropy generation of electromagnetohydrodynamic (EMHD) flow in a curved rectangular microchannel
Entropy generation of electromagnetohydrodynamic (EMHD) flow in a curved rectangular microchannel
复制标题
弯曲矩形微通道中电磁流体动力 (EMHD) 流的熵产生
DOI：
10.1016/j.ijheatmasstransfer.2018.06.147
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发表时间：
2018-12-01
影响因子：
5.2
通讯作者：
Tan, Wenchang
中科院分区：
文献类型：
--
作者：
Liu, Yongbo;Jian, Yongjun;Tan, Wenchang
本研究对牛顿流体通过弯曲矩形微通道的电磁流体动力 (EMHD) 流进行了熵产生分析。在热充分发展的假设和壁面热通量恒定的条件下，解析和数值导出速度和温度的分布，用于计算熵产生率。将速度的解析解与数值解和实验解进行了对比，并且一致性非常好。结果表明，流量和温度取决于电场强度（S）、磁场强度（Ha）、矩形截面纵横比（α）、曲率比（δ）、佩克莱数（Pe）和粘性耗散（Br）。然后在适当的无量纲参数下研究熵产生率。结果表明，局部熵产生从管壁向微通道中心线呈递减趋势。此外，熵产生率随着S和Br的增加而增加，但随着Pe和α的增加而减少。最后，当Ha较小时，熵产生率随着Ha的增加而增加，随着Ha的进一步增加，熵产生率达到恒定。目前的努力可用于设计高效的热微设备。 (C) 2018 Elsevier Ltd. 保留所有权利。
The entropy generation analysis of electromagnetohydrodynamic (EMHD) flow of Newtonian fluids through a curved rectangular microchannel is performed in this study. Under the assumption of thermally fully developed and the condition of constant wall heat flux, the distributions of velocity and temperature are derived analytically and numerically, which are utilized to compute the entropy generation rate. Analytical solutions of the velocity are contrasted with the numerical and experimental solutions and the agreements are excellent. The results show that the flow and the temperature depend on the strength of the electric field (S), magnetic field (Ha), aspect ratio of the rectangular cross section (alpha), curvature ratio (delta), peclet number (Pe) and viscous dissipation (Br). Then the entropy generation rates are investigated under the appropriate nondimensional parameters. The results show that the local entropy generation has a decreasing trend from the wall towards the centerline of the microchannel. Moreover, the entropy generation rate increases with the increase of S and Br but decreases with Pe and alpha. Finally, the entropy generation rate increases with the increase of Ha when Ha is small, and reaches a constant as further increase of Ha. The present endeavor can be utilized to design the efficient thermal micro-equipment. (C) 2018 Elsevier Ltd. All rights reserved.