Sluice gates are common hydraulic structures for controlling and regulating flow in open channels. This study investigates five models’ performance in distinguishing conditions of flow regimes, estimating the discharge coefficient ($C_d$) and flow rate. Experiments were conducted for different gate openings, flow rates, upstream and downstream conditions. New equation forms and methods are proposed to determine $C_d$ for energy–momentum considering losses (EML) and HEC-RAS models. For distinguishing the flow regimes, results indicated a reasonable performance for energy–momentum (EM), EML, and Swamee’s models. For flow rate and discharge coefficient performance of EM, EML, and Henry’s models in free flow and for EM and EML in submerged flow were reasonable. The effects of physical scale on models were investigated. There were concerns about the generality and accuracy of Swamee’s model. Scaling effects were observed on loss factor k in EML. A new equation and method were proposed to calibrate k that improved the EML model’s accuracy. This study facilitates the application and analysis of the studied models for the design or calibration of sluice gates and where the flow in open channels needs to be controlled or measured using sluice gates such as irrigation channels or water delivery channels of small run-of-river hydropower plants.

中文翻译：

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闸门设计和校准：区分流动条件和估计排放系数和流量的简化模型

闸门是用于控制和调节明渠流量的常见水工结构。本研究调查了五种模型在区分流态条件、估计流量系数（$C_d$) 和流速。针对不同的浇口开口、流速、上游和下游条件进行了实验。提出了新的方程形式和方法来确定$C_d$考虑损失的能量动量（EML）和HEC-RAS模型。为了区分流态，结果表明能量-动量 (EM)、EML 和 Swamee 模型的性能合理。对于自由流动的 EM、EML 和 Henry 模型以及淹没流动中的 EM 和 EML 模型的流量和流量系数性能是合理的。研究了物理尺度对模型的影响。有人担心 Swamee 模型的普遍性和准确性。在 EML 中观察到对损耗因子 k 的缩放效应。提出了一种新的方程和方法来校准k，从而提高了EML模型的准确性。