Backflow vortex behaviours in contra-rotating axial flow pump at low flow rates

D. Zhang, T. Tsuneda, Y. Katayama, S. Watanabe, S. I. Tsuda, A. Furukawa

Research output: Contribution to journalConference articlepeer-review

1 Citation (Scopus)


Backflow usually exists at the inlet of rotors of many turbomachines at low flow rates. In counter-rotating rotors applied for the axial flow pump, such vortical structures are also able to form. In our previous researches, some broad-banded pressure fluctuations in low frequency range have been observed between front and rear rotors, but we have not yet been able to explain what causes such phenomenon. In this study, in order to find out the causes of low frequency components at low flow rates, unsteady numerical simulations for the whole front and rear rotors are conducted, and casing pressure is experimentally measured at the inlet and outlet of front rotor and the inlet of rear rotor. It is found that vortical structures exist between front and rear rotors at below 40% of design flow rate. These vortices seem to be the result of shear layer instability at the impingement location of the exiting flow from front rotor to the backflow of rear rotor. The behaviours of these backflow vortices and their interaction with front rotor contribute the low frequency components in pressure fluctuations observed at low flow rates.

Original languageEnglish
Article number012036
JournalIOP Conference Series: Earth and Environmental Science
Issue number1
Publication statusPublished - Jul 30 2018
Event2017 AWG-IAHR Symposium on Hydraulic Machinery and Systems - Beijing, China
Duration: Nov 16 2017Nov 19 2017

All Science Journal Classification (ASJC) codes

  • Environmental Science(all)
  • Earth and Planetary Sciences(all)


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