Modélisation de l'effet du nombre de germes sur la cavitation à bulles en paroi d'un profil et sur les pressions produites

Modelization of the effect of the amount of germs on the cavitation with bubbles on the wall of a profile and on the pressures produced

¹ ALSTHOM-ACB, Centre d'études & recherches de Grenoble
² Ecole nationale supérieure d'informatique & de mathématique appliquée (ENSIMAG), Grenoble

Abstract

For a profile exhibiting a cavitation with bubbles, these bubbles will be all the more numerous, smaller and thinner when the microbubbles in the upstream liquid are also numerous. In a certain number of simplified hypotheses, an evolution model with "N bubbles" based on the principle of apparent powers is described. This model makes it possible to assess the evolution of the bubbles' mean radius as well as the change of pressures. The results obtained are compared with tests conducted in the CERG 2 m³/s tunnel.