Turbulent Elementary Votrices and New Development in Theory, Predicition, and control of Turbulence

湍流初等涡流及湍流理论、预测和控制的新进展

• 批准号: 12125101
• 负责人: KIDA Shigeo
• 金额: $ 4.1万
• 依托单位: Kyoto University (2003)National Institute for Fusion Science (2000-2002)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12125101/
• 关键词: Turbulence; Elementary Vortex; Turbulence Theory; Turbulence Prediction; Turbulence Control

The elementary vortices are the smallest coherent structures in turbulence. Their physical characteristics and dynamical roles in turbulence have been clarified by the theory, the experiment, and the computer simulation in various kinds of turbulence realized in nature, laboratories, and computers. The elementary vortices exhibit common physical characteristics independent of the kinds of turbulence, that is, a tubular central vortex is surrounded by spiral vortex layers, the diameter and swirl velocity obey the Kolmogorov scaling laws but the length of the vortex extends to the large scales of turbulence, the vortices make groups and are localized in space, and many elementary vortices tend to approach in an anti-parallel manner and enhance the mixing ability. As engineering and practical applications, the large-eddy-simulation model based on the elementary vortices, the active feedback control of the wall turbulence by manipulating the elementary vortices have been developed, and the mechanisms of the enhancement of supersonic mixing combustion by introducing the longitudinal vortices and the generation of tornados as the large-scale coherent vortex have been clarified. Furthermore, the unstable periodic motions (spatio-temporal coherent structure as the skeleton of turbulence) accompanying regeneration of elementary vortices have been discovered in the Couette turbulence. The concept and the dynamics of turbulent elementary vortices established in the present research project shall be useful for the future turbulence research.

基本涡是湍流中最小的相干结构。它们在湍流中的物理特性和动力学作用已通过理论、实验和计算机模拟在自然界、实验室和计算机上实现的各种湍流中得到阐明。基本涡具有与湍流类型无关的共同物理特征，即中心涡为螺旋涡层所包围，涡的直径和速度服从Kolmogorov标度律，涡的长度向湍流大尺度延伸，涡在空间上成团并局部化，并且许多基本涡倾向于以反平行方式接近并增强混合能力。在工程应用方面，建立了基于基元涡的大涡模拟模型，通过控制基元涡实现壁面湍流的主动反馈控制，阐明了纵向涡的引入对超声速混合燃烧的强化作用和大尺度拟序涡产生龙卷风的机理。此外，在Couette湍流中还发现了伴随着基元涡再生的不稳定周期运动（时空相干结构是湍流的骨架）。本研究所建立的湍流基元涡的概念和动力学特性对今后的湍流研究具有一定的参考价值。

项目成果

M.K.Yoshioka: "Significance of non-rotationalwind stress in the seasonal variation of continental torque"Tellus. (in print). (2002)

M.K.Yoshioka：“非旋转风应力在大陆扭矩季节性变化中的意义”Tellus。

Asai,M.: "Instability and Breakdown of the Three-Dimensional High-Shear Layer Associated with a Near-Wall Low-Speed Streak"Laminar-Turbulent Transition. 269-274 (2000)

Asai,M.：“与近壁低速条纹相关的三维高剪切层的不稳定性和破坏”层流-湍流转变。

S.Yanase: "Laminar flows through a curved rectangular duct over a wide range of the aspect ratio"Fluid Dynamics Res.. 31. 151-183 (2002)

S.Yanase：“在宽宽比范围内流经弯曲矩形管道的层流”流体动力学研究 31. 151-183 (2002)

M.Asai: "The Instability and Breakdown of a Near-Wall Low-Speed Streak"J. Fluid Mech.. 455. 289-314 (2002)

M.Asai：“近壁低速条纹的不稳定性和崩溃”J。

浅井雅人: "壁面吸込みによる平板上境界層の再層流化と再遷移"日本機械学会論文集(B編). 68. 1016-1021 (2002)

Masato Asai：“由于壁吸力导致平板上边界层的重新层化和重新转变”日本机械工程师学会汇刊（ed.B）68.1016-1021（2002）。