Natural convection of water -based nanofluids near the density maximum in an annulus
Natural convection of water -based nanofluids near the density maximum in an annulus
复制标题
环空中密度最大值附近水基纳米流体的自然对流
DOI：
10.1016/j.ijthermalsci.2020.106309
复制
发表时间：
2020-06-01
影响因子：
4.5
通讯作者：
Li, Ming-Hai
中科院分区：
文献类型：
--
作者：
Hu, Yu-Peng;Li, You-Rong;Li, Ming-Hai
本文提出了一系列关于水基纳米流体在环空中接近其密度最大值时的自然对流的数值模拟。纳米粒子的体积分数为0~0.08，纳米粒子直径为10~100 nm，环空半径比为0.1~0.8，密度反演参数为0~1。结果表明，存在密度反演现象的水基纳米流体的自然对流应考虑布朗运动。固体体积分数和半径比对流场和热场影响较大，而纳米颗粒直径影响较小。添加纳米粒子可以减弱甚至克服密度反转现象对传热性能的负面影响，有可能使其高于普通流体的传热性能。此外，含有金属或金属氧化物纳米粒子的纳米流体的传热性能优于含有非金属化合物纳米粒子的纳米流体。
This paper presents a series of numerical simulations on natural convection of a water-based nanofluid near its density maximum in an annulus. The volume fraction of the nanoparticles ranged from 0 to 0.08, the nanoparticle diameter from 10 nm to 100 nm, the radius ratio of the annulus from 0.1 to 0.8, and the density inversion parameter from 0 to 1. The results indicate that Brownian motion should be considered in natural convection of water-based nanofluid with the density inversion phenomenon. Both the solid volume fraction and the radius ratio affect greatly the flow and thermal fields, while the nanoparticle diameter has a little impact. Adding nanoparticles can weaken or even overcome the negative effect of the density inversion phenomenon on the heat transfer performance, possibly making it higher than that of the common fluid. Additionally, the heat transfer performance of the nanofluid with metal or metal oxide nanoparticles is better than that of the nanofluid with non-metallic compound nanoparticles.