Due to their economical and structural aspects, ogee-crested spillways can be constructed and operated in a wide variety of situations. In this study, a three-dimensional physical model (1:50 scale) was planned and constructed to investigate the impact of converging training walls of the ogee spillways with a curve axis on flow characteristics such as the discharge coefficient, free surface profile, flow depth and pressure on the spillway. For this purpose, the spillway was constructed, tested and verified in both the symmetrical and asymmetrical convergence of training walls ranging from 0° to 120°. Observations from flow depth and piezometric pressure along the spillway in various convergence angles indicate that as θ increases, the flow depth and piezometric pressure increase at the bottom and the toe of the spillway model. Also, in convergence angles of 60° and 90° tested in both symmetric and asymmetric states, the angles with lower L_ch/L have larger flow depth and piezometric pressure. The results of the experiments indicated that in the converging ogee spillway, by increasing the total upstream head, the discharge coefficient shows increment for each of the convergence angles (θ’s) and eventually the downstream flow changes its condition to either supercritical or critical stages. It must be considered that the discharge coefficient is independent of symmetric or asymmetric situations. On the other hand, at the submergence stage for the spillway, the difference in the discharge coefficient can be due to tailwater submergence occurring in some convergence angles. Also, the flow depth and the piezometric pressure on the bottom and the toe of the spillway increased more in the symmetrical convergence angles in comparison with the asymmetrical convergence angles. Also, by decreasing the downstream channel width to the crest length (L_ch/L), the flow depth and piezometric pressure increase subsequently. Results approved that the 60° convergence is the most economic convergence angle due to its capability in passing the largest flow discharge in the maximum head. The reason for this choice is that the crest length of this angle is 33% lesser than that of 120° convergence.

中文翻译：

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调查ogee溢洪道汇聚的训练墙对水力性能的影响

由于其经济和结构方面的原因，可以在多种情况下建造和运营全石膏顶溢洪道。在这项研究中，计划并构建了一个三维物理模型（比例为1:50），以研究带有曲线轴的ogee溢洪道的汇聚训练壁对流量特性（如流量系数，自由表面轮廓，流量）的影响溢洪道的深度和压力。为此，溢洪道是在0°至120°的训练墙的对称和非对称会聚中进行构造，测试和验证的。沿溢流口不同深度的流量深度和压强压力的观测表明，其为θ增加，溢流模型的底部和脚趾的水深和压强增加。同样，在对称和非对称状态下测试的60°和90°会聚角中，L _ch / L较低的角都具有较大的流量深度和测压压力。实验结果表明，在收敛的溢洪道中，通过增加上游总扬程，流量系数显示出每个收敛角（θ然后最终的下游流将其状态更改为超临界或临界阶段。必须考虑到放电系数与对称或不对称情况无关。另一方面，在溢洪道的淹没阶段，排放系数的差异可能是由于在某些收敛角度发生的尾水淹没所致。而且，与非对称收敛角相比，在对称收敛角处，溢洪道的底部和趾部上的流动深度和压强压力增加更多。此外，通过将下游通道宽度减小到波峰长度（L _ch / L），流量深度和测压压力随之增加。结果证明60°会聚是最经济的会聚角，因为它能够通过最大扬程中的最大流量。做出此选择的原因是该角度的波峰长度比120°会聚的波峰长度小33％。