Flow-induced vibration of core barrel of small modular reactor: Fluctuating pressure

Flow-induced vibration of the reactor internals involves complicated interactions between the fluids and structures, which is a key issue for the security of a nuclear power plant. A series of studies have been carried out to investigate the flow-induced vibration of a new designed small modular reactor. One of the important researches in these studies is to obtain the fluctuating pressure acting on the core barrel. In this paper, the fluctuating pressure acting on the core barrel was measured by the test, which can be used to normalize the pressure spectral density and calculate the correlation length of the turbulent flow field. The envelope and mean normalized pressure spectral densities versus the reduced frequency of the core barrel were obtained. The envelope normalized pressure spectral density can be used in the design analysis of flow-induced vibration, while the mean pressure spectral density can be used in the prediction analysis. Moreover, the influences of the flow rate on the correlation length were discussed.