Anomalous heat transfer enhancement by slip due to nanofluids in circular concentric pipes
Anomalous heat transfer enhancement by slip due to nanofluids in circular concentric pipes
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DOI：
10.1016/j.ijheatmasstransfer.2015.02.015
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发表时间：
2015-06
影响因子：
5.2
通讯作者：
M. Turkyilmazoglu
中科院分区：
文献类型：
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作者：
M. Turkyilmazoglu
本文研究了纳米流体在同心圆管内的对流换热，研究了表面部分速度滑移对纳米流体对流换热的影响以及由此产生的异常强化换热现象。采用单相纳米流体模型，考虑外壁加热、内壁绝热和内壁加热、外壁绝热的热边界条件，得到了充分发展的精确层流流场和温度场。所提出的速度和温度场的封闭形式的解决方案，以及努塞尔数推导能够解释不同的纳米流体和他们的贡献，异常水平的增强传热率，这是最近的文献的主要兴趣的滑移效应。结果清楚地表明，在实验和数值解中观察到的纳米流体流动发生在圆形同心形状的异常传热增强主要是由于速度滑移机制。
Convective heat transfer of nanofluids in circular concentric pipes under the influence of partial velocity slips on the surfaces and the resulting anomalous heat transfer enhancement are investigated in the present paper. Single phase nanofluid model is employed to get fully developed exact laminar flow and temperature fields accounting for the thermal boundary conditions of both the heated outer wall with the inner wall insulated and the heated inner wall with the outer wall insulated. The presented closed-form solutions of velocity and temperature fields as well as the Nusselt number derivation are able to explain the slip effects on different nanofluids and their contribution to anomaly level of enhancement in the rate of heat transfer, which is the main interest of the recent literature. Results clearly indicate that the anomalous heat transfer enhancement as observed in the experiments and numerical solutions of nanofluid flows occurring in the circular concentric shapes is mainly due to the velocity slip mechanism.