Nihon Kikai Gakkai ronbunshu (Aug 2015)

One-dimensional multidomain analysis of rotating cavitation

  • Takashi SHIMURA,
  • Satoshi KAWASAKI,
  • Masaharu UCHIUMI

DOI
https://doi.org/10.1299/transjsme.15-00125
Journal volume & issue
Vol. 81, no. 829
pp. 15-00125 – 15-00125

Abstract

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A method to analyze pump dynamic characteristics by cavitation compliance, mass-flow gain factor and dynamic gain was evolved to analyze rotating cavitation, using one-dimensional multi-domain system analysis software. This analysis method was used to analyze one-dimensional phenomena such as surge phenomenon in the past. For example, POGO, which is an auto-oscillation where the thrust oscillation of rocket propulsion system including turbopumps is coupled with the natural frequency of the rocket structure, has been analyzed using this method. In the present study, cavitation compliance and mass-flow gain factor were divided and distributed in each flow path of an inducer and tried to evaluate the possibility of analyzing rotating phenomena such as rotating cavitation by this one-dimensional analysis method. Whirl motion of the rotor assembly was accounted for by variable flow area orifices which connect the next flow path. The areas of the orifices are changed harmonically and the oscillation phase of each orifice is given according to the number of the blades. The variation of leakage flow rate through the tip clearances of each blade is simulated by the motion of the variable flow area orifices. With the evolved analysis model, effects of various parameters on the eigenvalues of the system were investigated. Analysis results showed that there existed rotating phenomena and agreed with inducer test results qualitatively.

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