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 α_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.

中文翻译：

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纳米颗粒形状对气泡周围纳米流体热毛细管对流传热和传质的影响

为了揭示纳米颗粒形状对纳米流体成核沸腾过程中传热的影响，进行了围绕气泡的纳米流体热毛细管对流的三维数值研究。在这项研究中使用了五种不同形状的纳米颗粒，并通过两相混合物模型模拟了纳米流体的流动。球形纳米颗粒与纳米流体的热毛细管对流强度最大，其次是叶片，砖块，圆柱和血小板形状。具有合适形状和相对较高体积分数的非球形纳米颗粒有利于传热增强，并且包含纳米流体的叶片状纳米颗粒具有最大的传热增强，其次是血小板，圆柱体和叶片形状。特别是作为α_p  = 0.05与球形纳米颗粒相比，带有叶片，血小板，圆柱和叶片形纳米颗粒的纳米流体的平均Nusselt数分别增加了22.8％，11.7％，7.7％和2.8％。此外，总的熵产生随着纳米颗粒球形度的增加而增加。