溢流孔分流齿坎对水舌形状及水垫塘底板冲击压力的影响

为了研究分流齿坎对水舌形状和水垫塘底板冲击压力的影响，在七表孔八深孔的泄洪拱坝模型试验中，对采用大差动带分流齿的溢流表孔的水舌形状和水垫塘底板冲击压力进行对比性试验。测量了单孔泄洪时齿坎对水舌形状和落水区域的影响，并研究了表孔和深孔联合泄洪时不同分流齿坎设置方案对水舌空中碰撞效果及水垫塘底板承受的冲击压力的影响，推荐了合理的齿坎布置方式。试验结果表明，采用中间表孔设置齿坎和边侧表孔不设置齿坎的整体布置形式，可以提高碰撞消能效果，减小水垫塘底板承受的最大冲击压力。

Effect of dentated bucket on nappe shape and impact pressure acting on plunge pool floor

The effect of dentated bucket on nappe shape and impact pressure acting on plunge pool floor downstream of the arch dam is studied in model test. The flood discharging structures of the dam to be studied include 7 openings of spillways and 8 midlevel outlets. The hydraulic characteristics of the nappe affected by different shapes of dentated bucket during flood releasing of single spillway opening are studied. It is found that the dentated bucket is effective in increasing the trajectory length of nappe and is helpful in enhancing the spreading of the nappe so that the impact pressure can be mitigated. Furthermore study shows that the reasonable operation combination of spillways and midlevel outlets is effective in enhancing the interactive impact of nappes in air resulted in the improvement of energy dissipation. The arrangement of flood releasing structure with dentated bucket spillway openings located at the central position and non-dentated bucket openings located on both sides is in favor of improving the energy dissipation of the project.