Numerical study of dissolved gas release induced by cavitation in a high speed channel flow

Cavitation often leads to performance degradation of hydraulic devices and, in some cases, to damage of the elements of their constructions (cavitation erosion). Liquids, that are used in technical devices, often contain dissolved gas. Such liquids are of particular interest because cavitation causes release of the dissolved gas into the cavities which can significantly change the flow structure. Mathematical models based on detailed description of all the underlying mechanisms still need development. The approach that was proposed and analyzed in the present study combines a simplified equilibrium model of liquid-vapor phase transition with a non-equilibrium diffusion model describing gas release process. The distributions of the hydrodynamic parameters and the gaseous phase fraction obtained show significant influence of the dissolved gas on evolution of cavitation structures. This is in qualitative agreement with experimental observations regarding the main features of cavitating flows and the behavior of the degassed air. It demonstrates robustness of the proposed simulation algorithm which means that its further development can be a promising way to create a universal model for reliable quantitative prediction of dissolved gas release.