Al/ oil nanofluids inside annular tube: an experimental study on convective heat transfer and pressure drop
Al/ oil nanofluids inside annular tube: an experimental study on convective heat transfer and pressure drop
复制标题
环形管内铝/油纳米流体：对流传热和压降的实验研究
DOI：
10.1007/s00231-017-2199-9
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发表时间：
2018
影响因子：
2.2
通讯作者：
Reza Jafarimoghaddam
中科院分区：
文献类型：
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作者：
A. Jafarimoghaddam;S. Aberoumand;K. Javaherdeh;A. A. Arani;Reza Jafarimoghaddam
本文对Al/ Oil纳米流体的制备稳定性、热物性、传热性能和摩擦因数进行了实验研究。电爆丝是目前最可靠的一步制备纳米流体的方法之一。以环形管为试验段，外管受到约204 W的均匀热流边界条件。所用的纳米流体以0.011%、0.044%和0.171%的三种不同体积浓度制备。研究了雷诺数、普朗特数、粘度、导热系数、密度、比热、对流换热系数、努塞尔数和摩擦因数等参数对传热过程的影响。该实验是在相对较低的雷诺数小于160，并在流体动力学充分发展的制度。结果表明，随着体积浓度和工作温度的升高，导热系数、密度和粘度增大，比热降低。更重要的是，它被观察到的对流换热系数和努塞尔数提高了28.6%和16.4%，分别为最高的体积浓度。最后，摩擦因数（这起着重要作用的泵送功率）被发现增加约18%的体积分数为0.171%。
In this work, an experimental study on nanofluid preparation stability, thermo-physical properties, heat transfer performance and friction factor of Al/ Oil nanofluids has been carried out. Electrical Explosion Wire (E.E.W) which is one of the most reliable one-step techniques for nanofluids preparation has been used. An annular tube has been considered as the test section in which the outer tube was subject to a uniform heat flux boundary condition of about 204 W. The utilized nanofluids were prepared in three different volume concentrations of 0.011%, 0.044% and 0.171%. A wide range of parameters such as Reynolds number Prandtl number, viscosity, thermal conductivity, density, specific heat, convective heat transfer coefficient, Nusselt number and the friction factor have been studied. The experiment was conducted in relatively low Reynolds numbers of less than 160 and within a hydrodynamically fully-developed regime. According to the results, thermal conductivity, density and viscosity increased depending on the volume concentrations and working temperatures while the specific heat declined. More importantly, it was observed that convective heat transfer coefficient and Nusselt number enhanced by 28.6% and 16.4%, respectively, for the highest volume concentration. Finally, the friction factor (which plays an important role in the pumping power) was found to be increased around 18% in the volume fraction of 0.171%.