Estimation of Discharge For Free Flow Under Sluice and Radial Gates

Estimation of the flow discharge under sluice and radial gates is an essential problem in many water engineering works. The results obtained from previous studies showed a lot of controversy and therefore need further research on this subject. In this investigation, the energy equation was used and the concept of increasing the pressure head created by water surface profile under the gates was considered. A semi theoretical equation was obtained for the estimation of the contraction coefficient (Cc) of flow under the sluice gates. This method decreased the mean absolute error of Cc less than 3%. To estimate the free flow discharge under radial gates, an analogy approach between sluice gates and radial gates has been presented. Semi-experimental equations, for both gates, were obtained by using some known data of other investigators. Field and laboratory data of many researchers were also used for the verification of the presented method. Results of this investigation showed that the presented equations are perfectly suitable for both sluice and radial gates.