Feedback Mechanism of Combinated Vibration Phenomenon of Fluid-Structure and Its Control

流固复合振动现象的反馈机制及其控制

基本信息

批准号：
10650156
负责人：
SAKAMOTO Hiroshi
金额：
$ 2.18万
依托单位：
Kitami Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

The objective of this study to investigate the feedback mechanism of combined vibration phenomenon of fluid-structure and its control. The rectangular prism with various ratio of depth having a fundamental structure configuration is adopted. The response characteristics of rotary oscillation of the rectangular prism are investigated on the free and forced vibration test. The suppression of the flow-induced vibrations is established by a T-shape plate and a splitter plate attached to the upstream and downstream of rectangular prism. The main results can be summarized as follows.(1) The fluctuating pressure on side surface of the prism except near the trailing edge is generated by impinging leading-edge vortex shed periodically from the leading edge of the prism.(2) Flow-induced vibrations of a prism with B/H=3 is induced by impinging leading-edge vortex and wake vortices. The T-shape plate suppresses the generation of impinging leading-edge vortex and the splitter plate suppresses the g … More eneration of the wake vortices.(3) The fluctuating moment of the prism with splitter plate is almost same to the plain prism. However, the fluctuating moment of the prism with T-shape plate greatly decreases in comparison with the plain prism. Therefore, it is recognized that flow-induced vibrations of the prism are strongly dependent on the impinging leading-edge vortices rather than the wake vortices.(4) The work done by fluctuating moment of the plain prism and the prism with splitter plate becomes a positive within forced oscillation frequency Sv<1.0 and flow-induced vibration diverges. On the other hand, the work of the prism with T-shape plate becomes almost zero value in the range of Sv=0 to 0.06. And the vibration converges because the work is negative in the range to Sv=0.23.(5) From the free-vibration test for the plain rectangular prism with impinging leading-edge vortices, it is found that there exists three types of flow-induced vibration, I.e., low-speed torsion flutter, vortex excitation and high-speed torsion flutter.(6) The vortex excitation is suppressed when the splitter plate is attached at the downstream of a prism. The low-speed and the high-speed torsion flutter and the vortex excitation are suppressed when the T-shape plate is attached at the upstream side. Therefore, suppression of the flow-induced vibrations of the prism is done with the most effectiveness when the impinging leading-edge vortices are suppressed with the T-shape plate. Less

流体结构对照的合并vinomenon的斗式机制，其具有基本的倾斜度的深度比例。形状板和下游的记录棱镜的下游 - 通过撞击前缘和唤醒涡流的振动会抑制Gentge涡流，而分离器E抑制了G的GTRISC T形板的棱镜大大降低了普通的ISM。另一方面，福利频率<1.0和流动诱导的振动在SV = 0到0.06的范围内几乎为零）从撞击领先的计划的自由振动测试中，它发现了三种类型的流动性病毒，即 - 速度扭曲，涡流激发和高速扭动当棱镜下游的附着在低速扭动和涡流时，激发会被抑制T形平台E抑制了最有效的前沿涡旋中的涡流。