| Autor: |
Tsuyoshi Hagiwara, Yasumi Kitajima, Koji Nishino, Masanobu Watanabe, Kazuyoshi Yonekura |
| Rok vydání: |
2009 |
| Předmět: |
|
| Zdroj: |
Volume 4: Fluid-Structure Interaction. |
| DOI: |
10.1115/pvp2009-77373 |
| Popis: |
The vibration response of a typical globe valve was measured to determine the characteristics of flow-induced vibration in a cavitating flow, varying valve opening rate from 20% to 40%, and flow rate from 0.2 m3 /min to 1.4 m3 /min or maximum flow rate of the test facility. Strain gauges were mounted on the valve shaft for these measurements. The upstream and downstream pressures of the globe valve were also measured to calculate the cavitation number or cavitation coefficient. Moreover, fluctuating pressures on the valve seat were measured simultaneously with strain signals to examine the correlation between the fluctuating fluid force and the vibration response. Cavitation occurred when the cavitation coefficient reached within the range from 0.42 to 0.47. On the other hand, the amplitude of the valve shaft in the drag direction increased drastically when the cavitation coefficient exceeded 0.8. The correlation between the fluctuating fluid force and the strain was investigated considering the sum of the measured pressures on the valve seat as fluctuating fluid force. A strong correlation between the fluctuating fluid force and the strain was obtained. The phase difference between fluctuating fluid force and the strain was about 40°. It was therefore concluded that the physical phenomenon was self-excited vibration coupled with a cavitating flow. This oscillation system is therefore considered as a negative damping system excited by the fluid force with time lag.Copyright © 2009 by ASME |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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