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This paper investigates the influence of pressure pulsation and flow-induced noise using a two-way dual-purpose pump. The pressure pulsation signal is obtained from the Detached Eddy Simulation (DES) turbulent model calculation as the fan sound source, and the noise sound field distribution in the impeller is calculated. The numerical results show that the external characteristics and pressure pulsation obtained from the simulation correlate well with the experimental values. Under different working conditions, the pressure pulsation decreases with the increase in the flow rate; no evident dominant frequency occurs in the frequency spectrum at a low flow rate, and many spurious frequencies occur. The primary frequency in the runner chamber is the leaf frequency, and that in the nonblade area is the rotating frequency. The sound field distribution of the flow-induced noise has dipole characteristics, and its directivity distribution and sound pressure radiation level can reflect the pressure pulsation characteristics. It is primarily affected by the blade frequency, and the distribution with the flow rate is consistent with the pressure pulsation. Avoiding a low flow and operating in a reasonable flow area can effectively reduce pressure pulsation and flow-induced noise and ensure the stability of unit operation. [ABSTRACT FROM AUTHOR]

In daily operation, the flow state in the runner chamber of an axial flow pump is extremely complex, and the pressure pulsation caused by the vibration of the unit and the hydraulic excitation is also extremely complex. The pressure pulsation will also greatly damage the flow components of the unit. In this paper, a pressure pulsation test and research on an axial flow pump in a pumping station are conducted. The research results indicate that the pressure pulsation at the inlet of the runner and the inlet of the front guide vane are basically consistent with the numerical simulation results under the rated operating conditions, and the external characteristic curves are basically consistent. When running in the forward direction, the pressure pulsation at the inlet of the runner periodically changes, and the main frequency is the rotational frequency. In the reverse operation, the main frequency of the pressure pulsation at the outlet of the runner is the rotational frequency, and the main frequency of the pressure pulsation at the outlet of the movable guide vane is the pilot frequency; the pressure coefficient changes under different flow conditions. The distribution trends are consistent and decrease with the increase in flow rate; the velocity streamlines are evenly distributed near the design flow rate but are sparse and uneven under low flow conditions. Deviation from the design flow rate should be avoided during normal operation of the unit conditions to ensure safe and stable operation. [ABSTRACT FROM AUTHOR]

When an axial-flow pump is running, there is a very complex flow inside the runner. Based on the two-way fluid–structure coupling method, this paper simulated the forward and reverse operating conditions of an axial-flow pump and calculated the dynamic stress distribution on the blade surface. The stress load spectrum was loaded onto the blade, and fatigue characteristic analysis was carried out to obtain the fatigue life and damage of the blade. This research shows the following: under different working conditions, the dynamic stress is concentrated at the root of the blade, and its amplitude decreases with the increase in the flow rate; at the same time, the change in stress with time shows a periodic change law. Under the working conditions of the turbine, the main frequency is the rotational frequency, and the secondary frequency is composed of multipliers of the rotational frequency, which is obviously affected by the number of blades; the fatigue damage and stress distribution are consistent, and the damage is the most serious at the stress concentration point. The research results of this paper can provide theoretical guidance for the structural design and safe operation of axial-flow pumps. [ABSTRACT FROM AUTHOR]