Effects of Nanoparticle Shapes on Heat and Mass Transfer of Nanofluid Thermocapillary Convection around a Gas Bubble
Effects of Nanoparticle Shapes on Heat and Mass Transfer of Nanofluid Thermocapillary Convection around a Gas Bubble
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DOI：
10.1007/s12217-019-09757-z
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发表时间：
2019-12-02
影响因子：
1.8
通讯作者：
Wang, Yang
中科院分区：
文献类型：
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作者：
Jiang, Yanni;Zhou, Xiaoming;Wang, Yang
为了揭示纳米颗粒形状对纳米流体泡核沸腾过程中传热的影响，对气泡周围的纳米流体热毛细管对流进行了三维数值研究。本研究使用了五种不同形状的纳米粒子，并通过两相混合模型模拟纳米流体流动。球形纳米流体的热毛细管对流强度最大，其次分别是叶片形、砖形、圆柱体和片状纳米流体。具有合适形状和相对较高体积分数的非球形纳米粒子有利于传热强化，含有叶片状纳米粒子的纳米流体的传热强化效果最大，其次分别是片状、圆柱状和叶片状。特别地，当α(p)=0.05时，具有叶片状、片状、圆柱状和叶片状纳米颗粒的纳米流体的平均努塞尔数相对于具有球形纳米颗粒的纳米流体的平均努塞尔数分别增加了22.8%、11.7%、7.7%和2.8%。此外，总熵产生随着纳米粒子球形度的增加而增加。
In order to reveal the influence of nanoparticle shape on heat transfer in nanofluid nucleate boiling process, a three-dimensional numerical investigation of nanofluid thermocapillary convection around a gas bubble is conducted. Five different shaped nanoparticles are used in this study and the nanofluid flow is simulated by two-phase mixture model. The thermocapillary convection intensity of nanofluid with spherical nanoparticles is the largest, which is followed by blade, brick, cylinder and platelet shapes, respectively. Non-spherical nanoparticles with a suitable shape and relatively high volume fraction are beneficial for heat transfer enhancement, and nanofluid containing blade shaped nanoparticles has the largest heat transfer enhancement, which is followed by platelet, cylinder and blade shapes respectively. In particular, as alpha(p) = 0.05 the average Nusselt number of nanofluid with blade, platelet, cylinder and blade shaped nanoparticles are increased by 22.8%, 11.7%, 7.7% and 2.8% relative to that of with spherical nanoparticle respectively. Moreover, the total entropy generation increases with nanoparticle sphericity increasing.