Empreintes dues à l'implosion de bulles isolées : Etude paramétrique expérimentale

Impressions due to the implosion of isolated bubbles: experimental parametric study

¹ EDF, DER, Châtou
² ENSTA, Palaiseau

Abstract

With the aim of gaining a better understanding of the significance of various parameters on the cavitation erosion mechanism, an experimental study has been conducted on the marking of polished materials subjected to the collapse of a vapour bubble engendered by a discharger inside a pressurizable vessel. The parameters studied are: the pressure inside the vessel P, the distance relating to the centre of a (d/R_max < 1.5) sample bubble, the material (99.99 % aluminium and 316 L stainless steel). Several conclusions can from now on be drawn: * The implosion of a bubble can engender many holes, which demontrates that the collapse in the form of a torus plays a determining part. * The maximum marking is obtained for a d/R value of less than 1.1. * For a given material, there exists a maximum permissible pressure below which no implosion is marked of about 0.07 MPa for aluminium and 0.15 MPa for steel.