通过掺气坎掺气试验,对小底坡明流泄洪洞的掺气坎下空腔回水问题进行了试验研究。结果表明:掺气坎后空腔回水的形成与空腔末端射流冲击角有密切关系。在试验条件下,约当θ>9°时,空腔回水开始出现。该冲击角实际上是各种水力、体型要素的综合反映。 Through the aeration aeration test, the problem of the backwater in the cavity under the aeration tank of the Mingliu flow discharge tunnel in Xiaodao Pole was studied. The results show that the formation of backwater in cavities with cavitation can be closely related to the jet impact angle at the end of cavities. Under the experimental conditions, cavity backwater begins to appear when θ> 9 °. The impact angle is actually a comprehensive reflection of various hydraulic and body elements.