接立面转弯隧洞的侧式出水口水力特性

Hydraulic Characteristics at Side Outlet of Tunnel Elbow

对于接立面转弯隧洞的侧式出水口,立面转弯隧洞的转弯段将直接影响侧式出水口的水力特性。若立面转弯隧洞参数设计不合理,极易导致侧式出水口内部发生流动分离。选取RSM紊流模型,针对接立面转弯隧洞的侧式出水口进行数值模拟,探究立面转弯隧洞曲率半径R、弯道后直隧洞长度L及转弯角度α等参数对出水口水力特性的影响规律,并对隧洞内流动过程进行了讨论。增加立面转弯隧洞曲率半径R和弯道后直隧洞长度L能显著改善出水口的水力指标。当曲率半径R≥12 D(D为隧洞直径)、弯道后直隧洞长度L≥16 D时,侧式出水口内部无明显流动分离,拦污栅断面流速分布均匀且无反向流速区。研究成果将对抽水蓄能电站侧式进/出水口的设计提供指导。

The turning section of tunnel elbow directly impacts the hydraulic characteristics at the side outlet.Improper design of elbow parameters easily causes flow separation within the side outlet.Numerical simulations on the side outlet connected to tunnel elbow were conducted using the RSM turbulent flow model to investigate the effects of parameters such as the radius(R)of curvatureof the elbow,the length(L)of straight tunnel downstream the bend,and the turning angle(α)on outlet hydraulics and also to examine the flow dynamics within the tunnel.Results demonstrate that increasing the radius(R)and length(L)significantly enhances the outlet’s hydraulic performance.Specifically,when R≥12 D(where D is the tunnel diameter)and L≥16D,flow separation inside the side outlet diminishes.The flow velocity distribution across the barrier section becomes uniform,eliminating backflow zones.These findings offer valuable insights for designing side inlets/outlets in pumped storage power plants.