The complexity of the formation mechanism of ventilated cavities makes it difficult to be explored experimentally. In this study, the formation mechanism of cavity regimes around a gas jet cavitator were first numerically predicted using the partially averaged Navier–Stokes (PANS) and homogeneous free surface models. The numerical framework was validated by comparing the numerical predictions with available experimental data. The numerical results showed that the cavity evolves across four different regimes with increasing ventilation rate, that is, bubbly flow, stable cavity, unstable cavity, and jet cavity. Moreover, the gas jet length in the front of the nozzle continues to increase, and the vortex structure in the cavity transitions from a streamwise vortex to a vortex filament. Furthermore, the correlation between the adverse pressure gradients and the characteristics of the cavity was analyzed, and the results demonstrated that the adverse pressure gradient leads to stagnation of the gas jet and cavity closure.

通风腔形成机理的复杂性使得很难通过实验进行探索。在这项研究中，首先使用部分平均的Navier-Stokes（PANS）和均质的自由表面模型来数值预测气体喷射空化器周围的空穴状态的形成机理。通过将数值预测与可用的实验数据进行比较来验证数值框架。数值结果表明，随着通气率的增加，气泡在四种不同的状态下演化，即气泡流动，稳定腔，不稳定腔和射流腔。此外，在喷嘴前部的气体喷射长度继续增加，并且腔中的涡旋结构从沿流的涡旋过渡到涡旋丝。此外，