Control of water air content during transient cavitation tests of inducers

Guy Caignaert (1, 2) , Olivier Coutier-Delgosha (1) , Jean-Baptiste Leroux (3)

1 LML - Laboratoire de Mécanique de Lille - FRE 3723
2 ENSAM - École Nationale Supérieure d'Arts et Métiers
3 LBMS - Laboratoire brestois de mécanique et des systèmes

The control of water air content is often necessary during transient cavitation tests of inducers. But no method is really defined or imposed to control it quantitatively, especially during tests where a continuous decrease of available NPSH at pump inlet is used in order to analyze, for example, the occurrence of instabilities. The paper intends to show how a well-known in-duct hydro-acoustics intensimetry, using three pressure transducers can be used accurately for the instantaneous determination of waves celerity in ducts during such transient tests, with an appropriate treatment of the measured pressures. The instantaneous wave celerity can then be related to an instantaneous value of air content using a model. An application to cavitation tests of an inducer at various speeds of rotation and a given non-dimensional flow rate is proposed, analyzed and discussed.

Mots clés: waves celerity; unsteady cavitation tests; pumps

Domaines: Mécanique [physics]

Guy Caignaert, Olivier Coutier-Delgosha, Jean-Baptiste Leroux. Control of water air content during transient cavitation tests of inducers. 16th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, Apr 2016, Honolulu, United States. ⟨hal-01894416⟩