脉动波对纳米颗粒运动及强化传热的作用机制

项目名称： 脉动波对纳米颗粒运动及强化传热的作用机制

项目编号： No.51476146

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 能源与动力工程

项目作者： 郑友取

作者单位： 浙江科技学院

项目金额： 65万元

中文摘要： 本项目通过高速摄影、Micro-PIV和热成像等实验手段以及格子波尔兹曼数值模拟方法，深入探索脉动波对纳米流体中纳米颗粒的响应频率、脉动振幅和纳米颗粒浓度分布均方差的作用机制；详细研究脉动波强化纳米流体两相传热的规律，区分其强化传热途径以及各个途径的贡献度，进而构建脉动波作用下纳米流体有效导热系数、有效黏度与纳米颗粒运动规律的传递函数，揭示脉动波作用下纳米流体强化传热的内在物理机理。此外，基于多组分格子玻尔兹曼方法，充分考虑纳米流体基液和纳米颗粒之间的各种相互作用力，同时结合大涡模拟方法，详细模拟实验室尺度的计算区域内的纳米流体在脉动波作用下的两相流动和传热特性，探索湍流效应对数值模拟结果的影响程度，修正脉动波作用下纳米流体两相流动和传热的大涡模型。研究结果为深入了解脉动波强化纳米流体传热提供经验公式和理论模型，对纳米流体的开发应用具有重要的指导意义。

中文关键词： 纳米流体；脉动波；强化传热；两相流；格子玻尔兹曼方法

英文摘要： The influence mechanisms of pulsating waves on nanoparticle response frequency and pulsating amplitude inside nanofluid as well as on the mean square deviation of nanoparticle distribution are studied in a deep-going way through experiments with high-speed photography, micro-PIV and thermal imaging technologies, and through numerical simulations based on lattice Boltzmann method (LBM). In addition, the two phase heat transfer enhancement of nanofluid under pulsating waves is investigated in detail with special efforts to distinguish different pathways of heat transfer enhancement, and to quantify the contributions of each pathways. Then, the transfer functions correlate either the effective thermal conductivity or the effective viscosity of nanofluid and the nanoparticle movements are developed.As a result,the underlying physical mechanisms for the heat transfer enhancement of nanofluid by pulating waves are revealed through the analysis of above transfer functions. On the other hand, multicomponent Lattic Boltzmann Method (LBM) is employed to simulate nanofluid flow and heat transfer inside a laboratory scale of computational zone. Various types of forces between the carrier liquid and nanoparticles are taken into consideration, and large eddy simulation method is combined into the LBM model.The effect of turbulence on the heat transfer results of nanofluid flow is explored, and the large eddy simulation model is improved for the problem nanofluid flow and heat transfer under pulsating waves. The results obtained in this project provide empirical formulas and theoretical models for nanofluid heat transfer enchancement by pulsating waves, which is important and very useful in the design and the applications of nanofluid.

英文关键词： nanofluid;pulsating waves;heat transfer enhancement;two phase flow;lattice Boltzmann method