In this study, the hydraulic characteristics of circular bottom intake orifices were investigated in a hydraulic model. The structure diverts the river-flow to a hydroelectric power plant through circular orifices located at the bottom of the channel. In the model, a series of circular holes of various diameters and locations at the bottom of a channel in the form of single and multiple holes were tested for different flowrates and screen angles (θ) to determine the flow diverting capacity of them. Discharges passing through orifices at known locations (x) and diameters (d) and screen slopes (θ) were measured and recorded along with the related main channel flow rates and depths (h). Using the dimensional analysis approach, an expression for the flow rate diverted from the main channel was derived as a function of related parameters, and their variations with each other were presented graphically and empirical equations were determined. Referring to the graphs and empirical equations, one can determine the discharge capacity of single and multiple intake orifices, which is important to calculate the amount of flow to be diverted from the main channel within the ranges of the related parameters used in this study.

中文翻译：

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圆形底部进水口的水力学

在这项研究中，在水力模型中研究了圆形底部进水口的水力特性。该结构通过位于渠道底部的圆形孔口将河流分流到水力发电厂。在该模型中，以单孔和多孔形式在通道底部的一系列不同直径和位置的圆孔针对不同的流量和筛网角度（θ）进行测试，以确定它们的分流能力。通过已知位置 ( x ) 和直径 ( d ) 和筛管斜率 ( θ ) 的孔口的排放量与相关的主通道流速和深度 ( h ) 一起被测量和记录。）。使用量纲分析方法，从主通道分流的流量的表达式被推导出为相关参数的函数，并且它们之间的变化以图形方式呈现并确定了经验方程。参考图表和经验方程，可以确定单个和多个进气孔的排放量，这对于计算在本研究中使用的相关参数范围内从主通道分流的流量很重要。