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Hirota, Kazuo*; Ishitani, Yoshihide*; Nishida, Keigo*; Sago, Hiromi*; Xu, Y.*; Yamano, Hidemasa; Nakanishi, Shigeyuki; Kotake, Shoji
Proceedings of 6th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-6) (USB Flash Drive), 8 Pages, 2008/11
CFD simulation using the Reynolds stress model was performed to evaluate turbulence-induced forces on the piping. The turbulence energy with the CFD simulation was compared with pressure fluctuation distributions obtained by the test with a 1/3 scale elbow simulating the JSFR hot-leg piping. The profile of turbulence energy was good agreement with that of the pressure fluctuation. The magnitude of pressure fluctuation can also be estimated from calculated turbulence energy multiplied by a certain coefficient. In the vibration analysis, the power spectrum density (PSD) of the pressure fluctuation was derived from the measured normalized PSD multiplied by the coefficient. The vibration analysis method was proposed based on the PSDs derived by the above procedure and correlation lengths. The analysis results of vibration response showed good agreement with the flow-induced-vibration test results, thereby it can be said that the vibration analysis method developed in this study is valid.
Hirota, Kazuo*; Ishitani, Yoshihide*; Nakamura, Tomomichi*; Shiraishi, Tadashi*; Sago, Hiromi*; Yamano, Hidemasa; Kotake, Shoji
Proceedings of 9th International Conference on Flow-induced Vibrations (FIV 2008), 6 Pages, 2008/00
The present study is intended to grasp flow-induced vibration characteristics in the piping by newly taken experimental data as well as to verify a vibration analysis tool with its data. It was found that a flow velocity-dependent periodic phenomenon with maximum random vibration force appears in the downstream region of the elbow. The Strouhal number of dominant pressure fluctuations in the downstream of elbow is estimated to be around 0.45. In addition, the validity of the analytical tool was confirmed by comparing between analysis and experiment.
Sago, Hiromi*; Hirota, Kazuo*; Ishitani, Yoshihide*; Yamano, Hidemasa; Kotake, Shoji
no journal, ,
A flow-induced vibration test has been performed with a 1/3 scale steel pipe simulating a actual FBR piping in order to establish a flow-induced-vibration evaluation method of a hot-leg piping in FBR. This test has measured a random vibration response and natural frequency of piping for the verification of the flow-induced-vibration evaluation method.
Hirota, Kazuo*; Ishitani, Yoshihide*; Uda, Nobuki*; Sago, Hiromi*; Yamano, Hidemasa; Kotake, Shoji
no journal, ,
A random vibration response has been calculated using correlation lengths and pressure-fluctuation power spectrum desities, which correspond to the input of a flow-induced-vibration analysis, obtained by a 1/3 scale water test simulating a FBR hot-leg piping.