纳米流体流动特性的多维模拟模型比较

Numerical Investigation Into the 3-D Simulation Models of Flow Characteristics in Nanofluids

纳米流体的流动特性是影响其强化换热的主要因素,流动特性的深入研究对纳米流体的强化传热机理将会起到重要的推动作用。只有准确描述纳米流体的流动特性,研究其换热过程才有意义。本文对纳米流体的三种不同计算模型进行了对比分析,并与实验相比较。结果表明:在数值模拟过程中,不能将纳米流体看成单一流体,必须考虑相间作用力,如果雷诺数比较低,布朗运动也不应该忽略。在计算精度上,单向流模型<Eulerian-Eulerian多相流模型<Euler-Lagrange多相流模型。

The main effect factors of the heat transfer enhancement in nanofluids are the flow characteristics. It plays quite an important role in deep investigation on the mechanism of heat transfer augmentation. Only by accurately describing the nanofluids flow characteristics, can it make sense for further exploration of the heat transfer process of nanofluids. This paper will make use of three different kinds of models to conduct researches on nanofluids. The results showed that the nanofluids can not be considered as one single-phase fluids and therefore the interactions between phases can not be neglected. The Brownian motion needs to be considered as well when the Reynolds number is very small. The results also revealed that the Euler-Lagrange multiphase model is the most precise and the single-phase model is the least precise, while the accuracy of the Eulerian-Eulerian multiphase model is in between.