常温水に対する多重プロセス型キャビテーションモデルの構築および検証（初生/崩壊および合体/分裂の導入）

抄録

In this study, we have constructed a new cavitation model for cold water by taking the main elementary processes in cavitation into account based on the moment method. Particularly, we have valued the modeling of inception/collapse and coalescence/break-up, which changes the number density of cavitation bubbles. The proposed model was implemented to a CCUP (Cubic interpolation propagation - Combined Unified Procedure) flow solver where compressibility of liquid-vapor two-phase flow can be incorporated, and the validation was performed in a specific condition around a hydrofoil of NACA0015. As a result, it was confirmed that the new model can reproduce the cavitation inception/collapse rate and coalescence/break-up rate around the hydrofoil, at least qualitatively. On the other hand, the present model could not reproduce a large-scale characteristic unsteady phenomenon such as “cloud cavity shedding”. One of the reasons is that the present cavitation model was constructed based on the bubble physics at low void fractions, which cannot be simply applied to the higher void fractions, and this defect should be improved in the near future.