Effect of swirl inflow on flow pattern and pressure fluctuation onto a single-elbow pipe in Japan Sodium-cooled Fast Reactor

Yamano, Hidemasa   ; Sago, Hiromi*; Hirota, Kazuo*; Hayakawa, Satoshi*; Xu, Y.*; Tanaka, Masaaki  ; Sakai, Takaaki

As part of the development of a flow-induced vibration evaluation methodology for the primary cooling piping in Japan Sodium-cooled Fast Reactor, important factors were discussed in evaluating the flow-induced vibration for the hot-leg piping. To investigate a complex flow near the inlet of the hot-leg piping, a reactor scale numerical analysis was carried out for the reactor upper plenum flow, which was simulated in a 1/10-scale reactor upper plenum experiment. Based on this analysis, experimental conditions on swirl inflow and deflected inflow that were identified as important factors were determined for flow-induced vibration experiments simulating only the hot-leg piping. In this study, the effect of the swirl inflow on flow pattern and pressure fluctuation onto the pipe wall was investigated in a 1/3-scale hot-leg pipe experiment. The experiment has indicated less significant for the pressure fluctuations, while the flow separation region was slightly influenced by the swirl flow. Computational fluid dynamics simulation results also appear in this paper, focusing on its applicability to the hot-leg piping experiments.