Accurate prediction of the discharge through radial gates is difficult. Existing calibration methods typically provide sufficient accuracy for free flows and submerged flows with jet Froude number at vena contracta larger than 1.7. However, their predictions are poor for submerged flows with jet Froude number less than 1.7. Based on the analysis of experimental data collected by the US Bureau of Reclamation, an empirical indicator was proposed to predict the approximate range of jet Froude number for submerged flows. Accordingly, submerged flows were subdivided into partially submerged flows with fully developed hydraulic jump, and totally submerged flows with undular or no jump. A new discharge calibration method, referred to as the identification method, was developed for the three distinct flow conditions. Verification of the proposed method indicated the discharge prediction accuracies were significantly improved for totally submerged flows.

通过径向浇口准确预测放电是困难的。现有的校准方法通常为自由流动和淹没流动提供足够的精度，在腔静脉收缩处射流弗洛德数大于1.7。然而，对于射流弗洛德数小于1.7的淹没流，他们的预测很差。在对美国填海局收集的实验数据进行分析的基础上，提出了一种经验指标来预测淹没流的射流弗洛德数的近似范围。因此，淹没流被细分为具有充分发展的水力跃变的部分淹没流，以及完全呈波浪形或无跃迁的完全淹没流。针对三种不同的流动条件，开发了一种新的排放校准方法，称为识别方法。