A new type axial diffuser is devised and the unsteady, three-dimensional and turbulent flow field in a plastic well pump with this diffuser is simulated based on a CFD method to exploit the internal pressure pulsation phenomenon in the diffuser. The pulsation characteristics of pressure at the first and second stage impeller outlets as well as inside the first and second stage diffuses are obtained under the duty flow rate conditions; meanwhile, the frequency fluctuation of pressure is analyzed by fast Fourier transform. Compared with a bowl diffuser, the hydraulic performance of the axial diffuser is slightly poorer, but much better than a radial diffuser. The maximum pressure pulsation occurs at the interface between the impeller and the axial diffuser, and the magnitude of the pulsation declines when the fluid passes the diffuser. From the inlet to the outlet, the amplitude of pressure pulsation in the axial diffuser is significantly reduced, indicating an excellent pressure recovery capability. In addition, the amplitude of pressure pulsation in the second stage diffuser is lower than that in the first stage. The dominant frequency at various monitoring points is equal to the blade passing frequency or is an integer multiple of the frequency. There are some differences in the frequency domain distribution from the first stage diffuser to the second stage one.
XU Yuan-Hui,ZHANG Qi-Hua,SHI Wei-Dong et al. Design of new type diffuser of plastic well pump and pulsation characteristics of internal pressure[J]. Journal of Drainage and Irrigation Machinery Engin, 2016, 34(1): 18-25.
WANG Yuqin, WANG Youmin. Adaptive internal model speed controller design for the permanent magnet liner synchronous motor [J]. Journal of Anhui University of Technology and Science, 2010, 25(1): 28-30.(in Chinese)
ZOBEIRI A, KUENY J L, FARHAT M, et al. Pump-turbine rotor-stator interactions in generating model: pressure fluctuation in distributor channel[C]//Proceedings of the 23rd IAHR Symposium on Hydraulic Machinery and Systems, 2006:17-31.
ZHU Rongsheng, SU Baowen, YANG Ailing, et al. Numerical investigation of unsteady pressure fluctuation in centrifugal pump [J]. Transactions of the Chinese society for agricultural machinery,2010, 41(11):44-47.(in Chinese)
YUAN Shouqi, XUE Fei, YUAN Jianping, et al. Experimental study on impact of pressure fluctuation on flow-noise in centrifugal pump [J]. Drainage and irrigation machinery, 2009, 27(5):287-290.(in Chinese)
JIANG Wei, LI Guojun, ZHANG Xinsheng. Efeect of oblique angle of balde trailing edge on pressure fluction in centrifugal pump [J]. Journal of drainage and irrigation machinery engineering, 2013, 31(5):369-372.(in Chinese)
ARNDT N, ACOSTA A J, BRENNEN C E, et al. Rotor-stator interaction in diffuser pump[J]. Journal of turbomachinery, 1989, 111(3): 213-221.
ARNDT N, ACOSTA A J, BRENNEN C E, et al. Experimental investigation of rotor-stator interaction in a centrifugal pump with several vaned diffusers [J]. Journal of turbomachinery, 1990, 112(1): 982-108.
TSUKAMOTO H, UNO M, HAMAFUKU H, et al. Pressure fluctuation downstream of a diffuser pump impeller[C]//Proceedings of the the 2nd Joint ASME/JSME Fluids Engineering Conference, Forum of Unsteady Flow, 1995: 133-138.
GONZALEZ J, SANTOLARIA C, BLANCO E, et al. Unsteady flow structure on a centrifugal pump: Experimental and numerical approaches[C]//Proceedings of the ASME 2002 Joint US-European Fluids Engineering Division Conference, 2002, 257(2B): 761-768.
IINO T, KASAI K. An Analysis of unsteady flow induced by interaction between a centrifugal impelle and a vaned diffuser[J]. Trans.Jpn. Soc. Mech. Eng. 1985, 51(471): 154-159.
DONG R, CHU S, KATZ J. Quantitative-visualization of the flow with in the volute of a centrifugal pump. Part B: Results [J]. ASME J. Fluids Eng, 1992, 114(3): 396-403.
AKIN O, ROCKWELL D. Flow structure in a radial flow pumping system using high-image-density particle image velocimetry[J]. ASME J. Fluids Eng, 1994,116(4): 538-544.
UBALDI M, ZUNINO P, BARIGOZZI G, et al. An experi-mental investigation of stator induced unsteadiness on centrifugal impeller out flow[J]. ASME J. Turbomach, 1996, 118:41-54.
WANG H, TSUKAMOTO H. Fundamental analysis on rotor-stator interaction in a diffuser pump by vertex method [J]. ASME J. Fluids Eng, 2001, 123:737-747.
WANG H, TSUKAMOTO H. Experimental and numerical study of unsteady flow in a diffuser pump at off-design conditions [J]. ASME J. Fluids Eng, 2003, 125: 767-778.
ZHOU Ling, SHI Weidong, LU Weigang, et al. Numerical simulation and experiment on deep-well centrifugal pump [J]. Transactions of the Chinese society for agricultural machinery, 2011, 42(3): 69-73.(in Chinese)