Study on pressure pulsation characteristics of a variable-speed circulating model pump

As the core hydrodynamic component of the circulation flow system, the circulating pump relies on variable speed regulation to reconsidered simulate different ocean conditions in the functional areas of the circulation flow system. Therefore, the study of unsteady pressure pulsation characteristics of the circulating pump under variable speed regulation is a crucial theoretical foundation for achieving system development goals. To address this issue, this study combines experimental measurements with numerical simulations to conduct a comprehensive investigation into the pressure pulsation characteristics within a circulating model pump under different rotational speeds. Continuous wavelet transform (CWT) is used to compare and analyze the pressure pulsation signals at various measurement points within the pump at different speeds. Based on the root mean square (RMS) values of pressure pulsation, the energy within the pump is quantitatively analyzed, and the relationship between pressure pulsation and flow characteristics is explored in conjunction with the evolution of vortex structures. The research results show that the pulsation energy at different speeds is mainly concentrated in the 0 ∼ 7 f BPF range, and the pressure pulsation energy varies similarly with the change of speed, reaching a maximum at the impeller outlet. With increasing rotational speed, the pressure pulsation energy corresponding to the blade passing frequency at each section tends to shift towards higher frequencies, and the energy gradually becomes concentrated near the impeller and inlet regions. The evolution period of the guide vane wake vortex is approximately 1/3 T at different speeds, which is the main hydraulic excitation source affecting the stability of the pump outflow.