Flow condition identification and discharge calibration for submerged radial gates

Abstract

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.

Keywords:

• Discharge coefficient
• discharge measurement
• flow condition
• hydraulic jump
• radial gate
• submerged flow

Additional information

Funding

This work was partly supported by the National Key Research and Development Program of China [grant number: 2017YFC0405103], IWHR Research & Development Support Program [grant number: HY0145B642017], and State Key Laboratory of SRWCRB Support Program of China [grant number: SKL2018TS07].