Sluice gate flow model considering section contraction, velocity uniformity, and energy loss

Abstract

The accurate prediction of sluice gate flow is critical for the management of irrigation and flood discharge, but existing models rely on certain assumptions that can compromise their results. This study develops a novel calculation model for sluice gate flow in both free and submerged conditions by examining the complete energy–momentum equations and taking into account factors such as section contraction, velocity uniformity, and energy loss. Numerical simulations were subsequently conducted to establish equations for the contraction coefficient, Coriolis, Boussinesq, and energy loss coefficient. Finally, a sluice gate flow experiment was conducted, and the results of this and previous experiments were used to compare the performance of the proposed model with that of simplified energy–momentum equation models as well as the Henry, Swamee, Simulation of Irrigation Canals, and Specification models. The results indicate that the smallest prediction error, measured at just 4.51 %, was demonstrated by the proposed model, which also exhibited the lowest sensitivity to the submergence degree. Therefore, this study advances the theoretical understanding of free and submerged flows and offers a valuable reference informing flow measurements during irrigation and flood discharge processes.