Prediction of critical submergence for multiple intakes by analytical method

In this study, the critical submergence for a group of multiple (four) intakes sited with different positions in an incoming uniform flow was investigated both experimentally and theoretically. Prediction of the critical submergence was performed by using potential solution. The total stream function was obtained as the sum of the stream functions of the point sinks (intake flows) and uniform canal flow. The theoretical (analytical) expression for the critical submergence of multiple pipe intakes sited in an incoming uniform canal flow with no imposed circulation was found by potential flow solution for the first time in this study. In this method, the effects of the intakes in the group on the intake under critical condition were investigated. The critical intake acts as if it works as an isolated intake with a discharge equal to the sum of discharges of all effective intakes (including the critical intake itself) in the group. Experiments were conducted to test whether or not the potential solution is valid. Potential solution results and experimental data were compared and it was found that the difference between them is in the range of %0-30.