摘要
本文分析了现有高溢流坝堰顶形状的不足之处,建议堰顶上游用椭圆曲线与上游堰面相切,堰顶下游用同一的指数曲线。运用二维数值模型优化研究了椭圆曲线的长、短半轴,提出一种新的溢流堰顶形状,称为南研型堰顶。最后,在水槽中对S=1/3、2/3及1的堰顶进行了验证试验,计算和试验的流量系数、堰顶压强水头基本一致,从而证明南研型堰顶形状可作为上游面倾斜的高溢流坝堰顶设计的依据。
In this paper unfavourable factors of existing spillway crest shapes for high overflow dams are analyzed. It is suggested that spillway crest shapes should be elliptic curve in the upstream of crest tangential to dam face and the same exponential curve in the downstream of crest. The one-half long and short axes of ellipse are optimally studied by 2-D numerical model and the new spillway crest shapes are designated as spillway crest of NHRI type. Further, the experiments are made in the flume for spillway crest of S=1/3, 2/3, 1. The discharge coefficients and crest pressure water heads of calculation and experiment are basically equal. From this, it is proved that EHRI type spillway crest shapes will be helpful to improve the hydraulic design of spillway dams with sloping upstream faces.
基金
水利水电科学基金项目
