Active Control of Vortex Shedding Frequency by Side-Jets

侧射流涡旋脱落频率的主动控制

• 批准号: 07650189
• 负责人: ARAI Norio
• 金额: $ 0.83万
• 依托单位: Tokyo University of Agriculture and Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650189/
• 关键词: Vortex Shedding; Strouhal Number; Sympathetic Vibration; Lock-in; Side-Jets; 渦放出

When a bluff body is placed in a flow, the body generates a separated flow region behind the body. That causes the generation of a vortex, which is grown along the flow, and shed into the wake. If the eigen frequency of the body corresponds to the vortex shedding frequency, the lock-in (sympathetic vibration) is occured, that is caused large damages to the body. Therefore, if the vortex shedding frequency could be controlled, it would be very useful in engineering.It this investigation, the control method using side-jets without any other new construction was applied to investigate whether the vortex shedding frequency can be controlled or not. Here the side-jets were inhaled at the point where the separation shear layr was generated. With emphasis on the performance of side-jets on the control of the vortex shedding frequency, both numerical simulation and experiment were carried out.The results are summarized as follows :・In the case of uniform suction side-jets, the characteristic is shown that the vortex shedding frequency is changed immediately in some narrow range with the change of side-jets velocity.・Suction side-jets have more effective influence on both the flow field and the vortex shedding frequency than injection side-jets.

当钝体放置在流中时，该钝体在其后面产生一个分离的流区。这就产生了一个旋涡，它沿着气流生长，并进入尾流。如果机体的本征频率与旋涡脱落频率相对应，就会发生锁紧（交感振动），对机体造成较大的损伤。因此，如果能够控制旋涡脱落频率，在工程上将是非常有用的。本研究采用不采用其他新结构的侧喷流控制方法来研究旋涡脱落频率是否可以控制。在这里，侧喷流在分离剪切层产生的地方被吸入。重点研究了侧向射流对旋涡脱落频率的控制作用，并进行了数值模拟和实验研究。结果总结如下：·在均匀吸力侧射流的情况下，旋涡脱落频率随侧射流速度的变化在一定窄范围内立即发生变化。·吸力侧射流对流场和旋涡脱落频率的影响比喷射侧射流更有效。

项目成果

新井紀夫,Hong Jun-ho: "サイドジェットによる渦放出周波数の制御" 流体力学講演会. 28. 141-144 (1996)

Norio Arai, Hong Jun-ho：“通过侧射流控制涡流脱落频率”流体力学会议。28. 141-144 (1996)。

ARAI,Norio and Hong, Jun-ho: "Control of Vortex Shedding Frequency by Side-Jets" Proc.of 28th Fluid Dynamics Conf.141-144 (1996)

ARAI,Norio 和 Hong, Jun-ho：“通过侧射流控制涡旋脱落频率”Proc.of 28th Fluid Dynamics Conf.141-144 (1996)