New equation for estimation of radial gate discharge

The flow discharge under a radial gate is a function of the geometric and hydraulic parameters upstream water depth, downstream water depth, gate opening, gate radius and trunnion pin height. A new equation for estimating radial gate discharge for movable trunnion pin height radial gates was developed based on comprehensive experimental testing with three such gates in a large laboratory flume (60×1×1 m). Data from previous field studies of 29 radial gates in the Doroodzan dam irrigation network were also used to derive new equations as functions of the above-mentioned parameters under free and submerged flow conditions. Dimensional analysis and non-linear regression were used to derive the water flow discharge relationships. These equations were validated using data of radial gates in the Doroodzan network and were also compared with several previously suggested equations for radial gates. Statistical results show good agreement between the proposed equations and field and laboratory data and they are hence recommended for use in practical applications.