Numerical prediction of interaction between turbulence structures and vortex cavitation

A novel numerical method to perform direct numerical simulations (DNS) of turbulent flow was established to predict the characteristics of compressible gas–liquid two-phase flow. A cavitation model was introduced to reproduce the phase change in the cavitation phenomena, and a DNS of wall turbulence of water with cavitation was performed. Vortex cavitation was observed in the wall turbulence. The growing cavity in the core of the vortex changed the vortex intensity. After vortex cavitation finished, the friction coefficient for the cavitating flow became lower than that of non-cavitating flow. The variation tendency of turbulent statistics corresponded to that of experimental measurements. For a small friction coefficient of the cavitating flow, the redistribution term in the streamwise component of the turbulent kinetic energy equation was reduced owing to the vortex cavitation. Consequently, it was proved that the occurrence of vortex cavitation modified the redistribution term, resulting in turbulence modification.