Cavity shedding mechanisms, such as those due to re-entrant jets (RJ) and condensation shocks (CS), are important but challenging topics in cavitating flows. This study investigates unsteady cavity shedding around a NACA66 hydrofoil using a self-defined compressible cavitation solver based on OpenFOAM with a dynamic cubic nonlinear subgrid-scale model. The predictions give satisfactory agreement with experimental data for the quantitative pressure evolution and the cavity shedding behavior induced by the re-entrant jet and the pressure wave. Moreover, the numerical data provides deeper insight into the pressure wave characteristics (e.g. propagation speed, wave intensity, shock Mach number, etc.) during cavity contraction. Multi-perspective analyses demonstrate that the pressure wave is a condensation shock which is responsible for the attached cavity abruptly disappearing. Additionally, the different influences of the re-entrant jet and the condensation shock on the local flow patterns are compared in detail in terms of the duration, average motion velocity, cavity behavior, formation mechanism and pressure intensity. The results show the condensation shock is characterized by fast propagation speed, short duration and high pressure pulse, which differs from the re-entrant jet features. This research provides an improved understanding of the cavity shedding mechanism around a cavitating hydrofoil and demonstrates the effectiveness of the current compressible cavitation solver.

空腔脱落机制，例如由重入射流 (RJ) 和冷凝冲击 (CS) 引起的脱落机制，是空化流中重要但具有挑战性的主题。本研究使用基于 OpenFOAM 的自定义可压缩空化求解器和动态三次非线性亚网格模型研究 NACA66 水翼周围的非定常空腔脱落。预测与实验数据的定量压力演化和由折返射流和压力波引起的空腔脱落行为令人满意地一致。此外，数值数据提供了对腔收缩期间压力波特性（例如传播速度、波强度、冲击马赫数等）的更深入了解。多视角分析表明，压力波是一种凝结激波，是导致附着空腔突然消失的原因。此外，从持续时间、平均运动速度、腔行为、形成机制和压力强度等方面详细比较了折返射流和凝结激波对局部流动模式的不同影响。结果表明，凝结激波与折返射流不同，具有传播速度快、持续时间短、压力脉冲高等特点。这项研究提供了对空化水翼周围空腔脱落机制的更好理解，并证明了当前可压缩空化求解器的有效性。从持续时间、平均运动速度、腔行为、形成机制和压力强度等方面详细比较了折返射流和凝结激波对局部流动模式的不同影响。结果表明，凝结激波与折返射流不同，具有传播速度快、持续时间短、压力脉冲高等特点。这项研究提供了对空化水翼周围空腔脱落机制的更好理解，并证明了当前可压缩空化求解器的有效性。从持续时间、平均运动速度、腔行为、形成机制和压力强度等方面详细比较了折返射流和凝结激波对局部流动模式的不同影响。结果表明，凝结激波与折返射流不同，具有传播速度快、持续时间短、压力脉冲高等特点。这项研究提供了对空化水翼周围空腔脱落机制的更好理解，并证明了当前可压缩空化求解器的有效性。结果表明，凝结激波与折返射流不同，具有传播速度快、持续时间短、压力脉冲高等特点。这项研究提供了对空化水翼周围空腔脱落机制的更好理解，并证明了当前可压缩空化求解器的有效性。结果表明，凝结激波与折返射流不同，具有传播速度快、持续时间短、压力脉冲高等特点。这项研究提供了对空化水翼周围空腔脱落机制的更好理解，并证明了当前可压缩空化求解器的有效性。