Study on the liquid jet and shock wave produced by a near-wall cavitation bubble containing a small amount of non-condensable gas

Abstract

The liquid jet and shock wave produced by a near-wall cavitation bubble are two major reasons resulting in material-wall damage. To better understand the destructive mechanism, the complete process of action of the multi-cycle cavitation bubble collapsing on the nearby wall with the effect of non-condensable gas under different stand-off distances was numerically investigated. For this purpose, a fully compressible solver is further developed with the implementation of a modified phase-change model. Validations were conducted by comparing the numerical results with the experimental data. Furthermore, the high-pressure zones on the wall induced by the shock wave and liquid jet are carefully analyzed. Numerical results reveal that the bubble behavior, shock wave propagation, and liquid jet types are highly associated with the stand-off distance. Finally, the potential material-wall damage is estimated by using the pressure impulse, and the relationship between the pressure impulse at the central point and the stand-off distance is quantitatively analyzed. It is found two pressure impulse peaks are at the central point.