Theree-dimensional dynamical structure of turbulence vortices Visualization and dynamics

湍流涡旋三维动力学结构可视化与动力学

• 批准号: 11837022
• 负责人: KIDA Shigeo
• 金额: $ 2.18万
• 依托单位: National Institute for Fusion Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11837022/
• 关键词: Turbulence; Coherent Vortex; Low-Pressure Vortex; Material Line; Material Surface; Rotational Shear Flow; Convection Vortex; Dipole Magnetic Field; 浮遊線; 乱流拡散; 熱対流渦; らせん渦層; ダイナモ; 可視化; 管状渦; 旋回流; 二重らせん構造; 渦の反平行接近; 渦のつなぎ替え

The structure and dynamics of coherent vortices in neutral and electrically conducting fluids are investigated by numerical simulation and visual analysis. We have found the following interesting results. [1] The stretching rates of material lines and surfaces in turbulence have been estimated accurately, and the place where the stretching is taking place most strongly is identified. [2] The method of low-pressure vortex analysis is applied to an isotropic turbulence. The Reynolds number dependence of various physical characteristics such as the size of cross-section, circulation, volume of tubular swirling vortices, as well as the spatial distribution suggests that concentrated vortices play a dynamically important role even at larger Reynolds numbers. An automatic tracking scheme of tubular vortices is developed, with which the life of each vortex can be analyzed more easily. [3] The life cycle (formation, development and breakdown) of straight coherent tubular vortices in a rotating shear turbulence of vanishing absolute vorticity is clarified by visualization and term-by-term analysis of the equations of motion. [4] In an axial magnetic dipole fields driven by thermal motion in a rotating spherical shell a typical dynamical cycle (generation and growth of thermal vortices, intensification of magnetic field, breakdown of vortices followed by diminution of magnetic field) is observed.

项目成果

柳瀬眞一郎: "回転一様剪断乱流中の基本渦構造"京都大学数理解析研究所講究録. (印刷中).

Shinichiro Yanase：“旋转均匀剪切湍流中的基本涡流结构”京都大学数学科学研究所 Kokyuroku（正在出版）。

S. Goto and S. Kida: "Nonuniform stretched weight In line statistics turbulence"Proc. Turbulence and shear flow phenomena. 2. 263-268 (2001)

S. Goto 和 S. Kida：“非均匀拉伸重量在线统计湍流”Proc。

田中満: "回転剪断乱流の絶対過度ゼロ状態"京都大学数理解析研究所講究録. 1121. 157-164 (2000)

田中满：“旋转剪切湍流的绝对零瞬态”京都大学数学科学研究所Kokyuroku。1121.157-164（2000）。

C.Das: "Overall Self-Similar Decay of Two-Dimensional Turbulence"J.Phys.Soc.Japan. 70. 966-976 (2001)

C.Das：“二维湍流的整体自相似衰变”J.Phys.Soc.Japan。

H.Miura: "Identification and analysis of vortex structures in a weakly compressible isotropic turbulence"Proc.1st Intern.Symp.on Advanced Fluid Information. 641-646 (2001)

H.Miura：“弱可压缩各向同性湍流中涡旋结构的识别和分析”Proc.1st Intern.Symp.on Advanced Fluid Information。