高海拔地区台阶式溢洪道水力特性研究

为了探究高海拔地区台阶式溢洪道水力特性,对坝顶位于海拔 2 586.0 m,斜坡角度 θ=32° 的某大坝台阶式溢洪道进行了模型试验。通过改变来流流量,研究了 3 种不同工况下溢洪道台阶竖直面及水平面时均压强、水面线、流速、脉动压强等水力特性。结果表明:在 3 种试验工况下,台阶式溢洪道不仅具有较高消能率,而且不会发生空化空蚀破坏;溢洪道竖直面及水平面压力沿程为跳跃式分布;水深及流速在台阶溢洪道上达到某一值后,基本稳定。该结果可为高海拔地区的台阶式溢洪道优化设计提供参考依据。

Hydraulic Characteristics of a Stepped Spillway at High Altitude

To explore the hydraulic characteristics of stepped spillway at high altitude,we conducted model test on the stepped spillway of a dam with slope θ=32°and dam crest at elevation 2586.0 m.By changing the incoming flow rate,we compared the hydraulic characteristics (time-averaged pressure in vertical and horizontal planes,wa-ter surface profile,flow velocity,and fluctuation pressure)in different conditions.Results prove that in all the three conditions,the stepped spillway has high energy dissipation efficiency and no cavitation.Pressure on step ver-tical plane and horizontal plane distributes in a bouncing manner along the spillway,and the height of water surface and the flow velocity will keep stable after reaching a certain value.