高水头泄水建筑物掺气坎体型研究

对具有高水头、大单宽流量的泄洪建筑物，工程中通常采用强迫掺气减蚀措施防止壁面发生空蚀破坏。本文主要通过物理模型试验研究方法，对高水头龙抬头明流泄洪洞反弧段下游底板和侧墙掺气减蚀进行了研究，提出了一种底部突跌凸型坎和侧墙加贴角联合掺气的新型掺气坎，解决了洞顶余幅、底空腔内回水和突缩引起掺气坎后形成水翅之间的问题。采用这种新型的掺气坎体型后，底空腔内没有回水，同时消除了反弧段后侧墙出现的清水区；侧空腔畅通并直接和底空腔相连，对侧墙和底板都起到了很好的保护。该体型对类似工程的设计及修复具有一定参考价值。

Experimental study on aerator type of hydraulic structures with high water head

Forced aeration device is usually introduced to prevent cavitation damage of hydraulic structures with high head and large-unit-discharge in engineering. In this paper based on model experiment, protecting cavitation damage by aeration measure was studied on soleplates and side-walls of the anti-arc bottom of the dragon-raise-head spillway tunnel. A new-style aerator with lateral deflector on the side-walls and vertical dropping on the soleplate for spillway tunnel was put forward through model test. The problem was solved that between residual area of tunnel, backwater in the bottom cavity and water-wing caused by lateral deflector on the side-walls. This original aerator eliminates un-airflow zone on the side-walls and backwater disappears in the bottom cavity. Lateral cavity formed by lateral deflector is unblocked. Simultaneity lateral cavity and bottom cavity are linked each other,which prevent cavitation damage of sidewalls and soleplates. This aerator is of reference value to design and repair of the similar projects.