Analyse de l'instabilité de cavitation dans un inducteur par modélisation de l'écoulement instationnaire en grille d'aubes

Analysis of cavitation instabilities in an inducer by modelling unsteady flows in a blade cascade

¹ Laboratoire des Ecoulements Géophysiques et Industriels, LEGI, BP 53, 38041 Grenoble Cedex 9
² Actuellement: Ecole Nationale d'Ingénieurs de Saint-Etienne. LTDS

Auteur de correspondance : reboud@hmg.inpg.fr

Abstract

An analysis of cavitation instabilities in rocket-engines inducers is developed by the LEGI in collaboration with the CNES and Snecma-Moteurs DMF. It is based on the modelling of the unsteady cavitating flow in a 2D blade cascade. Computations taking into account the complete coupling between the different blade-to-blade channels are carried out. They lead, according to the operation point, either to a stable and symmetrical behaviour of the cavitation on the different blades, or to a non-symmetrical and unsteady behaviour, showing in the different channels different structures of cavitation, whose distribution is in rotation with respect to the rotor. In these last cases, a super-synchronous instability, which agrees with experimental observations in this type of machine, is obtained in the stator frame.