Numerical calculation of axial-flow pump's pressure fluctuation and model test analysis

To study the significance of internal pressure pulsation characteristics between prototype and model pump devices, monitoring of computational fluid dynamics and dynamic measurement of a model were carried out under different working conditions and measuring points. The results of computational fluid dynamics calculation and model test are as follows. First, the positions of main frequency and subfrequency are almost the same, whereas the amplitude has a slight deviation. Second, the amplitude of inlet impeller is larger, and the main frequency is three times of rotating frequency. Third, the inlet speaker has mainly low pulsation, which is almost distributed in blade frequency and 1/3 times of rotating frequency. Moreover, the pressure pulsation of symmetrical points in each condition has a good symmetry. As the flow rate decreases, both the mixing and blade frequency amplitudes in the inlet speaker and impeller first decrease and then increase. The minimum mixing amplitude appears in the design condition of 253 L/s, whereas the blade frequencies are 203 and 253 L/s. The numerical calculation results are almost the same as those of prototype and model devices. Therefore, numerical calculations and experimental studies on pressure pulsation can guide the design and stable operation of similar pump stations.