The present study focuses on the inception, the growth, and the potential unsteady dynamics of attached vapor cavities into laminar separation bubbles. A viscous silicon oil has been used in a Venturi geometry to explore the flow for Reynolds numbers ranging from $Re=800$ to $Re=2000$. Special care has been taken to extract the maximum amount of dissolved air. At the lowest Reynolds numbers the cavities are steady and grow regularly with decreasing ambient pressure. A transition takes place between $Re=1200$ and $Re=1400$ for which different dynamical regimes are identified: a steady regime for tiny cavities, a periodical regime of attached cavity shrinking characterized by a very small Strouhal number for cavities of intermediate sizes, the bursting of aperiodical cavitational vortices which further lower the pressure, and finally steady super-cavitating sheets observed at the lowest of pressures. The growth of the cavity with the decrease of the cavitation number also becomes steeper. This scenario is then well established and similar for Reynolds numbers between $Re=1400$ and $Re=2000$.

中文翻译：

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雷诺数很低时从部分到超级空化的附着空化的发展

本研究的重点是附着的蒸汽腔进入层状分离气泡的开始，增长以及潜在的非稳态动力学。文丘里几何图形中已使用粘性硅油来探索雷诺数范围为$\mathrm{[R}Ë=800$ 至 $\mathrm{[R}Ë=2000$。已采取特殊措施以提取最大量的溶解空气。在最低的雷诺数下，空腔稳定并随着环境压力的降低而规则地增长。过渡发生在$\mathrm{[R}Ë=1200$ 和 $\mathrm{[R}Ë=1400$为此确定了不同的动力状态：微小空腔的稳定状态，附壁空腔的周期性膨胀状态（特征是中等大小的空腔的Strouhal值非常小），非周期性空化涡旋的爆发进一步降低了压力，并最终保持稳定在最低压力下观察到的超空化片。随着空化数的减少，空腔的生长也变得更加陡峭。这样就很好地建立了这种情况，雷诺数在$\mathrm{[R}Ë=1400$ 和 $\mathrm{[R}Ë=2000$。