Study on Flow Fluctuation Attenuation in the L-Shaped Pipe With Spring Vibrator

Abstract In view of the flow instability phenomenon that often occurs in passive residual heat removal system (PRHRS), the idea of using spring vibrator structure to attenuate flow and pressure fluctuations is proposed. Based on the finite element method, the fluid-solid coupling analysis is carried out in a typical L-shaped pipe which contains a spring vibrator structure. The results confirm the fluctuation attenuation effect of the spring vibrator structure. The simulation results shows that flow fluctuation amplitude at the outlet reduce, and the peak pressure which is the most threatening to thin-walled structures reduces. Based on the influence of relevant parameters on the attenuation coefficient, an optimized spring vibrator structure is obtained by changing the values of relevant parameters. Comparing the outlet flow fluctuation before and after the optimization of the spring vibrator structure, the flow fluctuation amplitude at the outlet is significantly reduced. The pressure fluctuation is greatly weakened compared with that before the optimization. The simulation results prove that the optimized spring vibrator has excellent fluctuation attenuation performance.