Subgrid scale modeling of cavitation inception*

Unresolved pressure fluctuations at the subgrid scale (SGS) level of any LES/RANS computation restrict the prediction of cavitation inception as SGS low pressures are ignored. Statistical relations of the SGS turbulence, the pressure fluctuations, and cavitating behavior of nuclei in such turbulence are used to build up a model of cavitation inception in the SGS. The fluctuating pressure history of Lagrangian nuclei of different sizes is used to solve the Rayleigh-Plesset equation to simulate the dynamics of bubbles. The evolution of the bubbles is analyzed, and a cavitation criterion is used to determine inception. Cavitation event statistics are built and tabulated for a range of SGS Reynolds numbers (????_??), nuclei size, TKE dissipation rate, and mean pressure. The table is used to estimate the cavitation event rate in each cell of the CFD solution. Two cases of homogeneous isotropic turbulence (HIT) at ????_??=240 and 324 have been studied where the pressure statistics predicted by the SGS model with LES are validated against DNS. A high ????_?? HIT flow is simulated using LES and cavitation events are compared against experimental data. The inception model successfully predicts the inception pressure and the cavitation rates in the flow.