Modulation of turbulent flow by cavitation in fluid machinery can cause vibrations, noise, and erosion. In this study, we confirm the cavitation phenomenon and observe its characteristics to predict the flow and control it accordingly. We perform a direct numerical simulation of the turbulent Couette flow of water with vortex cavitation using a cavitation model to predict phase change based on pressure distribution. In this simulation, we investigate the characteristics of the local interaction between turbulence vortices and cavitation and the global modulation of the turbulent flow, i.e. mean velocity and wall friction coefficient. We observe that a cavity is generated where a low-pressure region is created in the centre of the turbulence vortex; the growth of the cavity weakens the vortex and reduces the intensity of the turbulence. Further, the vortex becomes stronger as the cavity contracts; this phenomenon occurs repeatedly in a turbulent flow field with vortex cavitation. In a turbulent flow field with vortex cavitation, mechanical oscillations can occur spontaneously. In addition, we found that the turbulence vortex weakened by cavitation regenerates around the cavity. The unsteady phenomenon of the turbulence vortex cavitation repeatedly grows and decays monotonically; however, it does not necessarily repeat these spatially in the same manner. The spatial characteristics of the turbulence structure are different from those observed in single-phase turbulent flow.

流体机械中的空化对湍流的调制会导致振动、噪音和侵蚀。在这项研究中，我们确认空化现象并观察其特征以预测流动并相应地控制它。我们使用空化模型对具有涡旋空化的湍流 Couette 水流进行直接数值模拟，以根据压力分布预测相变。在这个模拟中，我们研究了湍流涡和空化之间的局部相互作用的特征以及湍流的全局调制，即平均速度和壁面摩擦系数。我们观察到在湍流涡的中心产生低压区域的地方产生了一个空腔；空腔的增长削弱了涡流并降低了湍流的强度。进一步，随着空腔收缩，涡流变得更强；这种现象在涡旋空化的湍流场中反复发生。在涡旋空化的湍流流场中，机械振荡会自发发生。此外，我们发现空化减弱的湍流涡在空腔周围再生。湍流涡空化的非定常现象反复增长，单调衰减；但是，它不一定以相同的方式在空间上重复这些。湍流结构的空间特征与在单相湍流中观察到的不同。机械振荡可以自发发生。此外，我们发现空化减弱的湍流涡在空腔周围再生。湍流涡空化的非定常现象反复增长，单调衰减；但是，它不一定以相同的方式在空间上重复这些。湍流结构的空间特征与在单相湍流中观察到的不同。机械振荡可以自发发生。此外，我们发现空化减弱的湍流涡在空腔周围再生。湍流涡空化的非定常现象反复增长，单调衰减；但是，它不一定以相同的方式在空间上重复这些。湍流结构的空间特征与在单相湍流中观察到的不同。