方、矩形环管湍流直接数值模拟分析:Ⅱ.雷诺应力场与平均能量谱,对传统湍流本构关系的再认识

发布时间：2018-03-05 07:26

本文选题：壁湍流　切入点：雷诺应力　出处：《中国科学:物理学力学天文学》2017年08期 　论文类型：期刊论文

【摘要】：通过对直管道内充分发展湍流的直接数值模拟,建立方、矩形环管内充分发展湍流数据库,其中包括详细的湍流统计数据:(1)湍流平均流场,即平均流向速度与湍流驱动平均二次流(史称Prandtl第二类二次流);(2)湍流雷诺应力场;(3)湍流时均能量谱.本文给出了方、矩形环管内充分发展湍流雷诺应力场分布信息,对90°凸角域附近的Prandtl第二类二次流生成项结构进行了仔细剖析,特别诠释了凸角域二次流的生成机理.将方、矩形环管90°凹角附近的流场,包括平均流场(流向速度,平均二次流)和雷诺应力场中的湍动能,与现有的实验和直接数值模拟数据进行详细对比验证,展示了方、矩形环管内直接数值模拟结果的有效和合理性.基于对湍流雷诺应力场和能量谱特征的观察,本文提出了重新审视和认识传统湍流本构关系的必要性.对标量涡黏系数所隐含的各向同性物理涵义与假设给出严格数学证明,在此基础上,提出了以张量涡黏系数描述湍流各向异性运动特征的研究思路,给出了发展以描述各向异性湍流运动为目标的新型湍流本构关系.基于此关系进一步提出未来研究设想,即发展基于直接数值模拟结果的雷诺平均湍流封闭模型,以提高雷诺平均模拟的物理可靠性和准确度.
[Abstract]:By direct numerical simulation of fully developed turbulent flow in a straight pipe, a fully developed turbulence database in square and rectangular annular tubes is established, which includes detailed statistical data of turbulence: 1) turbulent mean flow field. That is, mean flow velocity and turbulent driven average secondary flow (formerly known as Prandtl second type second flow) turbulent Reynolds stress field / energy spectrum in turbulent flow. In this paper, the distribution information of turbulent Reynolds stress field in square and rectangular annular tube is given. The second generation term structure of Prandtl secondary flow near 90 掳convex angle region is analyzed in detail, and the mechanism of secondary flow generation in convex angle region is explained in particular. The flow field near 90 掳concave angle of square and rectangular ring tube, including the average flow field (flow velocity), is analyzed. Mean secondary flow) and turbulent kinetic energy in Reynolds stress field are compared in detail with available experimental and direct numerical simulation data. The validity and rationality of direct numerical simulation results in rectangular annular tubes. Based on the observation of Reynolds stress field and energy spectrum of turbulent flow, In this paper, the necessity of reexamining and understanding the traditional constitutive relation of turbulence is put forward. On the basis of the strict mathematical proof of the isotropic physical meaning and hypothesis implied by the eddy viscosity coefficient of scalar turbulence, In this paper, a new kind of turbulent constitutive relation, which is developed to describe anisotropic turbulent motion, is proposed. Based on the new constitutive relation, the future research ideas are put forward, based on which Zhang Liang's eddy viscosity coefficient is used to describe the characteristics of turbulent anisotropic motion. A Reynolds mean turbulence closure model based on direct numerical simulation is developed to improve the physical reliability and accuracy of the Reynolds mean simulation.
【作者单位】：复旦大学航空航天系;大连理工大学工程力学系工业装备结构分析国家重点实验室国际计算力学研究中心;
【基金】：国家自然科学基金(编号:91434112) 上海教育委员会数值仿真联合创新计划项目(编号:AR908.D1RW.002) 复旦大学航空航天系、上海千人计划启动项目(编号:EZH2126503) 大连理工大学和工业装备结构分析国家重点实验室(编号:S12202)资助项目
【分类号】：O357.5

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