Abstract In the present study, a large eddy simulation was conducted to simulate the three-dimensional cavitation turbulence flow inside a Helmholtz oscillator under a high Reynolds number. Numerical results show reasonable agreement with available experimental observations and data. Under the validated solution strategy, the cavitation flow is visualized in a straightforward manner and indicates the primary shedding and secondary shedding induced by the shear layer and collision wall. The evolution and the interactions between cavitation and vortices are well captured and discussed in detail. The results show that flow inside the chamber can be divided into three stages, the boundaries of which are where the vortex reaches the wall surface and where a stable vortex ring is formed on the collision wall. The cavity length has an important influence on frequency, indicating that axial constraints have a greater effect on frequency than radial constraints do. A coherent structure is used to reveal the influence of vortex-wall interactions, and the structure shows that there is a close relationship between the vortex-cavitation interaction and the flow mechanism. Our work provides insight into the internal flow of the Helmholtz oscillator and represents further efforts to demonstrate the mechanism of the oscillation jet.

中文翻译：

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亥姆霍兹振荡器内部自激振荡的大涡模拟

摘要 在本研究中，进行了大涡模拟以模拟高雷诺数下亥姆霍兹振荡器内部的三维空化湍流。数值结果与可用的实验观察和数据显示出合理的一致性。在经过验证的求解策略下，空化流以直接的方式可视化，并指示由剪切层和碰撞壁引起的一次脱落和二次脱落。空化和涡流之间的演变和相互作用被很好地捕捉和详细讨论。结果表明，腔室内部的流动可分为三个阶段，其边界是涡流到达壁面的位置和在碰撞壁上形成稳定涡环的位置。腔长对频率有重要影响，说明轴向约束比径向约束对频率的影响更大。一个相干结构被用来揭示涡-壁相互作用的影响，该结构表明涡-空化相互作用与流动机制之间存在密切的关系。我们的工作提供了对亥姆霍兹振荡器内部流动的洞察，并代表了证明振荡射流机制的进一步努力。