Prédiction de l'apparition de la cavitation dans un inducteur placé en amont d'une roue centrifuge

Prediction on cavitation onset in an inducer placed in front of a centrifugal impeller

¹ Equipe Hydraulique de l'INSA de Lyon
² Equipe Turbomachines du LMFA, UMR-CNRS 5509 ECL/UCB, LYON I, Société METRAFLU

Abstract

During the last ten years, pump manufacturers are faced to achieve, during the design process, a better understanding of flow properties in order to obtain a wider range of flow rate and, for the case of hydraulic machines, to be able to control cavitation effects.

Inducers are usually placed in front of radial impellers to gain in flow rate capability with a given initial head. For low flow rates, cavitation is responsible for severe pressure and mass flow fluctuations at low frequencies that may cause damage for the machine itself and for its environment.

An attempt is done in order to predict the apparition of cavitation near the leading edge of an inducer for different flow rates by means of a theoretical calculation of the blade static pressure distribution using an Euler 3D approach. Results are compared with experimental investigations of cavitation onset by means of NPSH evalutation.