Three-dimensional Instability of the Flow Induced around an Oscillating Cylinder in a Density Stratified Fluid at Rest

静止密度分层流体中振荡圆柱体周围流动的三维不稳定性

• 批准号: 06640528
• 负责人: TATSUNO Masakazu
• 金额: $ 1.34万
• 依托单位: KYUSYU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640528/
• 关键词: Stratified Fluid; Oscillating Motion; Non-linearlity; Secondary Flow; Three-dimensional Instability

The structures of the flow induced by a vertical circular cylinder performing transverse oscillations in a linearly stratified fluid at rest are investigated. The density gradient inhibits the onset of the three-dimensional instability. The instability appears as regularly spaced streaked flows along the cylinder axis. Each streaked flow is shed being oscillated along the cylinder surface. Regularly spaced streaked flows arrange themselves alternately along the cylinder axis as the oscillating motion of a streaked flow is 180ﾟ out of phase with adjacent streaked flows.When the non-dimensional amplitude or frequencies are increased beyond critical values, the streaked flows generated alternately along the cylinder axis do not oscillate along the cylinder surface but extend straight in the direction of cylinder oscillation in the same manner as in the homogeneous fluid.

本文研究了垂直圆柱在静止线性分层流体中作横向振荡时所引起的流动结构。密度梯度抑制了三维不稳定性的发生。不稳定性表现为沿着圆柱轴的规则间隔的条纹流。每一条条纹流都是沿圆柱表面沿着振荡而脱落的。当条纹流的振荡运动与相邻条纹流的相位相差180 °时，规则间隔的条纹流沿圆柱轴线交替地沿着排列。当无量纲振幅或频率增加到超过临界值时，沿圆筒轴线交替沿着产生的条纹流不沿圆筒表面沿着振荡，而是以相同的方式沿圆筒振荡的方向直线延伸如在均匀流体中。

项目成果

辰野正和: "密度成層流中における振動二次流れ" 第26回流体力学講演会講演集. 225-228 (1994)

Masakazu Tatsuno：“密度分层流中的振荡二次流”第 26 届流体力学会议论文集 225-228 (1994)。

M.Tatsuno: "Secondary flow around an oscillating cylinder in a stratified fluid" Proc.26th Fluid Dynamics Conference, Fukuoka. 225-228 (1994)

M.Tatsuno：“分层流体中振荡圆柱体周围的二次流动”，第 26 届流体动力学会议，福冈。