Study on flow induced vibration evaluation for a large scale JSFR piping, 2; Vibration analysis in 1/3 scale hot-leg piping experiments under swirl inflow conditions

大型JSFR配管の流力振動評価に関する研究,2; 旋回状流入条件下でのホットレグ配管1/3縮尺試験における振動解析

馬場 丈雄*; 廣田 和生*; 佐郷 ひろみ*; 山野 秀将   ; 相澤 康介 ; Xu, Y.*

Baba, Takeo*; Hirota, Kazuo*; Sago, Hiromi*; Yamano, Hidemasa; Aizawa, Kosuke; Xu, Y.*

A two-loop primary cooling system for a Japanese large-scale sodium-cooled fast reactor requires increased coolant velocity and large piping diameter, raising a flow-induced-vibration issue. This study is intended to grasp flow-induced vibration characteristics using 1/3-scale elbow test sections and verify a vibration analysis tool. The parameter range of swirl flow velocity ratio was set at 5%-15%. The random force distributions along the pipe and their correlation length were measured with pressure sensors. The influence of the pressure fluctuation due to swirl flow was found to be negligible. The power spectrum densities of pressure fluctuations and correlation lengths were classified to evaluate flow-induced random vibration response. The vibration analysis method is based on the measured power spectrum densities and correlation lengths of turbulent-flow induced forces. The analysis results showed good agreement with the flow-induced-vibration test results.