Analysis of internal flow excitation characteristics of reactor coolant pump based on DMD

This paper presents a study on the internal flow characteristics of reactor coolant pumps using Dynamic Mode Decomposition (DMD) technology. As a core component of nuclear power plants, the internal flow characteristics of reactor coolant pumps play a crucial role in the performance and stability of the pumps. This paper initially introduces the application of DMD and Proper Orthogonal Decomposition (POD) methods in fluid mechanics, emphasizing the effectiveness of DMD in analyzing the dynamic characteristics of flow fields. A computational model of the reactor coolant pump was constructed, and numerical simulation of the internal flow field under non-uniform inflow conditions was conducted. The impact of the lower chamber of the steam generator on the pump's inlet conditions was evaluated. The numerical simulation results were analyzed using DMD technology, extracting flow characteristics and revealing the main flow modes and dynamic behaviors in the flow field. The results demonstrate that the DMD technology can accurately capture the time-dynamic characteristics within the flow field, providing crucial insights for optimizing performance and preventing faults in the reactor coolant pump.