湍流自然对流新模型及其实验验证

项目名称： 湍流自然对流新模型及其实验验证

项目编号： No.51266004

项目类型： 地区科学基金项目

立项/批准年度： 2013

项目学科： 能源与动力工程

项目作者： 王烨

作者单位： 兰州交通大学

项目金额： 58万元

中文摘要： 湍流自然对流是新能源利用和传统工业等领域常见的物理现象，具有高温差大尺度等特点，从而Ra数很高。由于在实验室很难建立很高Ra数的湍流自然对流模型，所以用数值方法研究高Ra数湍流自然对流成为切实可行的方法，而工程计算中最常用的k-ε模型的数值研究结果与实验结果之间存在较大差异。为了获得精度较高、适应面广的湍流模型，本项目在分析常用模型缺陷基础上，用理论分析法构造一湍流普朗特数σt，并以它为核心建立求解湍流自然对流的新k-ε模型；用已发表的实验数据从流体属性和对流面曲率两方面对新模型进行考核和修正，使新模型在满足工程计算精度情况下达到较理想的普适度；再通过实验方法对模型所用σt的物理意义进行解释。项目研究结果是一适用于求解不同Pr数介质、不同对流表面曲率湍流自然对流问题的新模型，对进一步描述和认识湍流自然对流具有重要的科学意义和学术价值，而且作为一种研究工具具有广泛的应用前景和工程实用价值。

中文关键词： 自然对流；湍流；湍流模型；湍流普朗特数；

英文摘要： Turbulent natural convection, as a common physical phenomenon in the fields of new energy use and traditional industries, has been received considerable attention because it determines the efficiency of energy using. Moreover, the Rayleigh number is very large because in these cases the temperature difference is large and also the length scale. The studies of turbulent natural convection with large Rayleigh number are impossible to be carried out through experimental method because the cost of the test equipments is very high or there is no enough space in the laboratory to build the test equipments. In such circumstances, the numerical simulation becomes the most effective method to analyze the turbulent natural convection having large Rayleigh number. At present, the k-ε model is the most popular model to simulate the turbulent natural convection for engineering purposes. But the difference between the numerical results of the k-ε model and the experimental results are always very significant owing to many reasons. Thus, it is necessary to develop a new k-ε model to accurately capture the main characteristics of turbulent natural convection. After analyzing the shortcomings of the common k-ε model, this project uses the theoretical analysis method to transform the momentum equation and the energy equation of

英文关键词： natural convection；turbulence；turbulent model；turbulent Pandtl number；