横向射流湍流拟序结构对强化传热的作用机理

项目名称： 横向射流湍流拟序结构对强化传热的作用机理

项目编号： No.51476145

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： 李国能

作者单位： 浙江科技学院

项目金额： 83万元

中文摘要： 提高换热器的换热效率是一项重要的低碳能源技术,需要不断寻求新的强化传热技术和方法。本项目着眼于研究横向射流湍流拟序结构对强化传热的作用机理，通过高速摄影、三维PIV和热成像等实验测量技术，揭示横向射流湍流拟序结构的扩展和脉动规律，探索湍流拟序结构对换热体强化传热的影响因素，构建横向射流湍流拟序结构对强化传热作用的传递函数，探明横向射流湍流拟序结构影响传热的途径和关键参数。在实验研究的基础上，将格子-玻尔兹曼方法和大涡模拟方法相结合，修改大涡模拟方法中滤波函数的参数以获得适合当前研究问题的湍流黏度，系统描述在横向射流湍流拟序结构作用下换热体边界层的流动结构变化、涡系演化特征和传热特性，进一步探究横向射流湍流拟序结构对强化传热的规律和内在作用机制。研究结果将为深入了解横向射流湍流拟序结构对强化传热的作用机理提供经验公式和理论模型，同时对换热器的开发应用具有重要意义。

中文关键词： 横向射流；拟序结构；强化传热；传递函数；格子-玻尔兹曼方法

英文摘要： Improving the heat transfer efficiency of the heat exchangers is an important low-carbon energy technology, and new methods to enhance the heat transfer are obviously needed. This project focuses on the influence mechanism of the heat transfer enhancement by the turbulent coherent structures in the system of jet in cross-flow.The regular patterns of the spreading and the pulsating process of the turbulent coherent structures, as well as the influences of the turbulent coherent structures on the heat transfer enhancement, are studied through high-speed photography, 3D-PIV and thermal imaging technologies. The transfer function correlates the turbulent coherent structures in the system of jet in cross-flow and the heat transfer enhancement is obtained. The pathways of the heat transfer enhacement and the critical parameters are revealed. On the other hand and based on the experimental studies, a program combining the lattice Boltizmann method and the large eddy simulation method is developed. The parameters of the filter function in the large eddy simulation method are optimized to obtain a compatible turbulence viscosity for the present investigations. The motion of the flow sturctures inside the boundary layer, the evolution of the vortices and the corresponding heat transfer process are described and analyzed in detail. The influence mechanism of the heat transfer enhancement by the turbutlent coherent structures in the system of jet in cross-flow is revealed. This project provides depth understanding of the influence mechanism of the heat transfer enhancement by the turbulent coherent structure, and provides empirical formulas and the theoretical models. The results obtained in this project are important and very useful in the design and the applications of high efficient heat exchangers.

英文关键词： jet in cross-flow;coherent structures;heat transfer enhancement;transfer function;lattice Boltzmann method