Dynamics and Statistics of Worms around a Calumnar Vortex

周涡周围蠕虫的动力学和统计

• 批准号: 12640387
• 负责人: MIYAZAKI Takeshi
• 金额: $ 2.24万
• 依托单位: The University of Electro-Communications
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640387/
• 关键词: Turbulence; Ordered Vortex; Fine Eddies (Worms); Blocking Effect; Vortex Wave; Velocity Correlation; 乱流微細渦構造; 大振幅渦波; Blocking effect; エネルギーカスケード; 直接数値計算; RDT; スカラー輸送

The interaction between a columnar vortex and external turbulence is investigated numerically. A Lamb-Oseen vortex is immersed into initially isotropic homogeneous turbulence, which, itself, is produced numerically by a direct numerical simulation of decaying turbulence. The formation of inhomogeneous fine turbulent eddies around the columnar vortex and the vortex-core deformations are studied in detail, by visualizing the flow field. The initially random turbulent eddies (worms) are wrapped around the columnar vortex, and become like vortex rings (or sprirals). Statistical quantities, such as two-point-energy-spectrum and two-point-enstrophy spectrum, are evaluated by averaging 20 realizations and compared with the theoretical predictions by a. rapid distortion theory (RDT). The axial velocity correlation dominates near the vortex surface, whereas the radial velocity correlation becomes larger, where the worms are wrapped. If the columnar vortex is strong compared with the external turbulence, external velocity disturbances are blocked by the vortex and they cannot penetrate into the vortex core directly, whereas various types of vortex waves (Kelvin waves) are excited by the external pressure disturbances.

数值研究了柱状涡流与外部湍流之间的相互作用。羔羊 - 欧文涡流浸入最初的各向同性均匀湍流中，该湍流本身是通过直接对衰减湍流的数值模拟来数字产生的。通过可视化流场，详细研究了圆柱涡流周围和涡旋核变形周围的不均匀细性涡流涡流的形成。最初的随机湍流涡流（蠕虫）被包裹在柱状涡旋上，并变成涡旋环（或刺激）。通过平均20个实现来评估统计数量，例如两点 - 能量 - 光谱和两点超声谱，并与a的理论预测进行了比较。快速失真理论（RDT）。轴向速度相关性在涡流表面附近占主导地位，而径向速度相关变化更大，在蠕虫被包裹的地方。如果与外部湍流相比，柱状涡流强劲，则外部速度干扰会被涡流阻塞，并且无法直接渗透到涡旋芯中，而各种类型的涡流波（kelvin波）则被外部压力干扰激发。

项目成果

T. Miyazaki, H. Isshi, J.C.R. Hunt: "Statistics of Turbulence around a Columnar Vortex "Geometry and Statistics of Turbulence""Publishers. 217-222 (2001)

T.宫崎、H.一志、J.C.R.

T.Miyazaki,H.Ishio,J.C.R.Hunt: "Geometry and statistics of Turbulence"T.Kamke et al, Klumer. 398 (2001)

T.Miyazaki、H.Ishio、J.C.R.Hunt：“湍流的几何和统计”T.Kamke 等人，Klumer。

T.Miyazaki, H.Ishii, J.C.R.Hunt: "Geometry and Statistics of Turbalence"Kluner Acadenic Publishers. 398 (2001)

T.Miyazaki、H.Ishii、J.C.R.Hunt：《湍流的几何与统计》Kluner Acadenic 出版社。

T. Mikyazaki, Y. Furuichi, N. Takahashi: "Quasigeostrophic Ellipsoidal Vortex Model"J. Phys. Soc. Japan. 70(7). 1942-1953 (2001)

T. Mikyazaki，Y. Furuichi，N. Takahashi：“准地转椭圆体涡模型”J。

K.Yamamoto,N.Takahashi,T.Kambe: "Geometry and Statistics of Turbulence"T.Kambe et al, Klumer. 398 (2001)

K.Yamamoto，N.Takahashi，T.Kambe：“湍流的几何和统计”T.Kambe 等人，Klumer。