Numerical simulation of cavitation flow in axial flow pump and induced pressure fluctuation

作者：Zhang Desheng^*; Pan Dazhi; Shi Weidong; Zhang Guangjian

来源：Journal of Huazhong University of Science and Technology (Natural Science Edition), 2014, 42(1): 34-38.

DOI：10.13245/j.hust.140108

• Axial flow pump
• Blade passing frequency
• Cavitation conditions
• Harmonic frequency
• Net positive suction heads
• Net positive-suction head required
• Pressure fluctuation
• Unsteady cavitation

Performance curves and unsteady cavitation pressure fluctuation in the axial flow pump were simulated and analyzed based on modified SST k-ω turbulence model and cavitation model. Numerical results show that predictive error values of head, efficiency and hr (net positive suction head required) in design condition are 3.41%, 4.10% and 6.32% respectively, compared to the experimental results. Cavitation bubbles are distributed in 10%~30% areas of chord in suction side, which increases from hub to tip gradually. The dominant frequency of pressure fluctuation at impeller outlet in cavitation condition is the blade passing frequency (BPF), and the harmonic frequency is the times of BPF. The amplitude of the fluctuation near tip, which is affected by the serious cavitation bubbles, is about 4 times of that near hub in hr condition. However, the difference between them reduces gradually in the guide vane outlet. The amplitude of pressure fluctuation near tip is only about 40% of that near hub. The cavitation tends to be serious as h (net positive suction head) decreases, and the amplitude of pressure fluctuation increases significantly. The amplitudes at impeller inlet in different cavitation conditions vary little because of the less cavitation effect on the impeller upstream flow field.

• 出版日期2014