scholarly journals A study on leakage-flow-induced vibrations. 4th report. Fluid-dynamic forces and moments acting on walls of a narrow passage when one of them is vibrating in coupled translational and rotational modes.

1989 ◽  
Vol 55 (511) ◽  
pp. 618-626 ◽  
Author(s):  
Fumio INADA ◽  
Shinji HAYAMA
Keyword(s):  
Fluid Dynamic ◽  
Leakage Flow ◽  
Dynamic Forces ◽  
Narrow Passage ◽  
Flow Induced Vibrations

A Parameter Study of Leakage-Flow-Induced Vibrations

2009 ◽  
Author(s):  
Fumio Inada
Keyword(s):  
Fluid Dynamic ◽  
Parameter Study ◽  
Single Degree Of Freedom ◽  
One Dimensional ◽  
Translational Vibration ◽  
Dynamic Damping ◽  
Narrow Passage ◽  
Rotational Vibration ◽  
Flow Induced Vibrations ◽  
The Stability

The stability of thin plate able to execute translational or rotational vibration in a one dimensional narrow passage is studied, and critical flow rates are obtained theoretically. The effect of pivot point of rotational system is considered. In the case of single-degree-of-freedom rotational system, the pivot position greatly influences stability. Instability can occur when the passage is divergent in the case of translational vibration. When the pivot of rotational vibration is at the entrance of the passage, the region of negative fluid-dynamic damping can become very small, and flutter can hardly occur. When the pivot is at the slightly behind the center of the passage, the instability region can become large, and even if the passage shape is convergent, instability can occur.

Study on Mechanism for Unstable Vibrations of an Axisymmetric Body in a Cavitating Leakage Flow

2002 ◽  
Author(s):  
Masaaki Arai
Keyword(s):  
Cross Sections ◽  
Fluid Dynamic ◽  
Axisymmetric Body ◽  
The Self ◽  
Leakage Flow ◽  
Cavitation Bubbles ◽  
Dynamic Damping ◽  
Dynamic Forces ◽  
The One ◽  
Theoretical Results

An axisymmetric body in a cavitating narrow annular parallel passage attains the self-excited vibrations when the apparent passage formed by the cavitation bubbles becomes certain conditions. This paper presents experimental and analytical studies on the mechanism for such unstable vibrations. In order to examine the apparent passage, the cross-sections of the leakage flow containing the cavitation are observed in the one-dimensional leakage model. When the self-excited vibrations occur, the cavitation bubbles disappear in the vicinity of the exit. Relating these apparent passages to the annular passage, the fluid-dynamic forces acting on an axisymmetric body are investigated theoretically. The theoretical results show that the fluid-dynamic damping is negative when the unstable vibrations occur experimentally.

Sign in / Sign up

Export Citation Format

Share Document