The present paper analyses the advantages and limitations of using numerical modelling to simulate hydraulic jumps at high Froude numbers. Two hydraulic jumps of the same Froude number (7.5) but different Reynolds numbers were simulated using Improved Delayed Detached Eddy Simulation. The free surface was captured using the Volume of Fluid multiphase model with a High-Resolution Interface-Capturing technique. Flow properties including velocity, total pressure and air concentration profiles were compared with experimental results at different streamwise locations. It was observed that while the simulations were able to accurately capture the velocity and pressure fields, the air concentration values were over predicted, although the air concentration distribution was successfully reproduced. Since the simulations capture the complete three-dimensional flow field, further analysis of different physical mechanisms contributing to air entrainment are also carried out. The turbulent kinetic energy and the vorticity field were examined to understand the air–water flow dynamics. The coherent structures responsible for air entrainment were identified using vortex identification techniques. The influence of these structures on the air-entrainment mechanisms is presented with pertinent discussions.

中文翻译：

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建模液压跳跃：IDDES与实验

本文分析了使用数值模型来模拟高弗劳德数下的水力跳跃的优点和局限性。使用改进的延迟分离涡流模拟对相同弗洛德数（7.5）但雷诺数不同的两个水力跳跃进行了模拟。使用具有高分辨率接口捕获技术的流体多相模型捕获自由表面。将包括速度，总压力和空气浓度曲线在内的流动特性与不同流向位置的实验结果进行了比较。可以观察到，尽管模拟能够准确地捕获速度场和压力场，但尽管成功地再现了空气浓度分布，但空气浓度值还是超出了预测值。由于模拟捕获了完整的三维流场，因此还对导致空气夹带的不同物理机制进行了进一步分析。检查了湍动能和涡度场以了解空气-水流动力学。使用涡流识别技术识别负责夹带空气的相干结构。通过相关讨论介绍了这些结构对引气机制的影响。