掺气减蚀设施不仅能有效地减缓空蚀和磨蚀的发生,而且具有一定的消能作用.结合某水电站溢洪道的模型试验研究,分析了溢洪道掺气减蚀工程措施的消能效果,并首次定量地计算了消能率.试验和计算结果表明,在高水头、大单宽流量溢洪道中每道掺气挑坎的消能水头为2～5 m,随着级数的增加消能水头逐渐增加.试验还表明,在满足掺气要求和水流流态平稳的条件下,尽可能多设置掺气设施不仅不会增加工程量,还可以降低泄槽因高速水流冲刷破坏的风险,而且有利于下游消能防冲设计的优化.%Air entrainment facilities can not only effectively reduce the occurrence of cavitation and abrasion, but also has a certain role on energy dissipation. Combining with the experimental research of a spillway model, the energy dissipation of the aerator in the spillway is analyzed and the energy dissipation rate is firstly quantified. The results show that the head will decrease about 2-5 m after flowing through an aerator in a spillway with high water head and large unit discharge, and the head decrease will be increased with the increase of the number of aerators. The experimental study also shows that, under the conditions of meeting the requirements of aeration and keeping flow stable, setting the aerators as much as possible will not increase the construction quantity, but it can reduce the risk of chute damage due to high-speed flow and is beneficial to the optimization of downstream energy dissipation and erosion control designs.
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