The cavitation is ubiquitous in the water delivery system of high hydraulic head navigation locks. This paper studies the choked cavitation characteristics of the gap flows in the valve lintel of the navigation locks and analyzes the critical self-aeration conditions. The cavitation gap flow in the valve lintel is experimentally and numerically investigated. A visualized 1:1 full-scale slicing model is designed, with a high-speed camera, the details of the cavitation flow is captured without the reduced scale effect. Moreover, the numerical simulations are conducted to reveal the flow structures in the gap. The experimental results show that the flow pattern of the gap flow in the valve lintel could be separated into four models, namely, the incipient (1) the developing, (2), the intensive, (3), and the choked (4) cavitation models. The numerical simulation results are consistent with the experimental data. The choked cavitation conditions are crucial to the gap flow in the valve lintel. When the choked cavitation occurs, the gap is entirely occupied by two cavitation cloud sheets. The gap pressure then decreases sharply to the saturated water vapor pressure at the operating temperature. This water vapor pressure is the ultimate negative pressure in the gap that remains unchanged with the continuous decrease of the downstream pressure. The volumetric flow rate reaches a peak, then remains constant, with the further decrease of the pressure ratio or the cavitation number. At the choking point, the volumetric flow rate is proportional to the root mean square of the difference between the upstream pressure (absolute pressure) and the saturated pressure of the water. Moreover, the pressure ratio is linearly correlated with the downstream cavitation number with a slope of (1 + Ϛ_c).

在高液压头导航锁的输水系统中普遍存在气蚀现象。本文研究了导航锁的气门缝中的间隙流的窒息气蚀特性，并分析了临界自充气条件。实验和数值研究了气门中的气穴间隙流。设计了一个可视化的1：1满刻度切片模型，并使用高速相机拍摄了空化流的细节，而没有减小的刻度效果。此外，进行了数值模拟以揭示间隙中的流动结构。实验结果表明，气门缝中间隙流的流动模式可以分为四个模型，即初始阶段（1）发展阶段（2），集中阶段（3）和阻塞阶段（4）。空化模型。数值模拟结果与实验数据吻合。气穴堵塞的条件对于气门中的间隙流动至关重要。当发生阻塞的气蚀时，间隙完全被两个气蚀云片占据。然后，间隙压力在工作温度下急剧下降至饱和水蒸气压力。该水蒸气压力是间隙中的最终负压，其随着下游压力的持续降低而保持不变。随着压力比或空化数的进一步减小，体积流量达到峰值，然后保持恒定。在阻塞点，体积流量与上游压力（绝对压力）和水的饱和压力之差的均方根成比例。此外，Ϛ _Ç）。