Open AccessInfluence of Rotational Speed of an Inducer on the Propagation Velocity of Super-synchronous Rotating Cavitation
Author(s) -
Sota Kondo,
Moena Kanamaru,
Shigeo Kawasaki,
Yuka Iga
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1909/1/012050
Subject(s) - rotational speed , cavitation , mechanics , physics , rotor (electric) , rotation (mathematics) , rocket (weapon) , specific speed , inducer , rotational temperature , vibration , angular velocity , acoustics , centrifugal pump , classical mechanics , engineering , aerospace engineering , chemistry , impeller , spectral line , mathematics , geometry , quantum mechanics , astronomy , biochemistry , gene
The phenomenon that a cavity rotates faster than the rotational speed of the pump in the direction of rotation is called super-synchronous rotating cavitation (super-S RC). It is known that super-S RC is often observed in rocket turbopumps, but that it is rare to be observed in industrial pumps. Therefore, we form a hypothesis that its occurrence is related to the rotational speed of pumps. In this study, experiments of an inducer were conducted at four rotational speed at Kakuda Space Center in the Japan Aerospace Exploration Agency. The pressure fluctuation and the rotor vibration were measured, and the propagation velocity ratio of super-S RC and the frequency of unsteady cavitation in the super–S RC were determined at each rotational speed. As a result, when the cavitation number is the same, the propagation velocity ratio is almost the same regardless of the rotational speed of the inducer. It means that the faster the rotational speed, the faster the unsteady cavitation oscillates in the inducer despite the condition of the same cavitation number. It indicates that rotating cavitation does not occur under a certain rotational speed because of the limitation of the frequency of unsteady cavitation, which is known in hydrofoil.