Discussion of “Revisiting the Energy-Momentum Method for Rating Vertical Sluice Gates under Submerged Flow Conditions” by Oscar Castro-Orgaz, Luciano Mateos, and Subhasish Dey

Abstract

The respected authors introduced a rational analysis and modified the generalized energy-momentum (EM) method presented in the work of Castro-Orgaz et al. (2010) for the calibration of submerged sluice gates. Bijankhan et al. (2012) theoretically indicated that the proposed method of Castro-Orgaz et al. (2010) cannot be accurate enough in low submergence zones and reported that the method yielded nonphysical answers in some ranges of submerged sluice gate operations. Here, the discussers aim to: 1. Investigate the performance of the EM method of CastroOrgaz et al. (2010) for low submergence zones based on experimental data compiled by the discussers for both low and high submergence zones, which are scarce in the literature (Sepulveda et al. 2011); and 2. Verify the accuracy of the revised EM method in the original paper throughout the entire range of the submergence conditions based on the compiled data. A large-scale experimental flume was constructed in the University of Tehran to study different aspects of the sluice gate flow. It is a 6 m long, 1.179 m wide, and 1 m deep rectangular flume made of Plexiglas. The gate was installed 2 m downstream of the inlet section and a tailgate was installed at the downstream end of the flume to adjust the depth of the tailwater. The discharge was measured by using an electronic flow meter and a point gauge with an accuracy of 0.1 mm was used to measure the water depths. Adopting the notation of the original paper, the data were compiled within the nondimensional variable range presented in Table 1. Plotting the experimental data along with a submergence distinguishing condition curve identified the operating ranges of the current experimental data Fig. 1. In this regard, Eq. (1) was used to evaluate the distinguishing condition curve (Swamee 1992):