Critical submergence for side circular intake in an open channel flow

Formation of an air-entraining vortex in the vicinity of an intake structure is considered to be a major problem of the intake. These vortices are not acceptable as they decrease the efficiency of the intake structures. Adequate submergence above the intake can effectively halt the formation of such vortices. The present study deals with the analytical and experimental works carried out on a horizontal side circular intake with and without bellmouth transitions in an open channel flow. The parameters affecting the critical submergence of intakes have been identified and relevant parameters have been used to develop relationships for the critical submergence of the side circular intakes. The accuracy of the proposed relationships is well within the acceptable limit. The results of the present study can be utilized by field engineers and practitioners for the rational design of side intakes used for diverting flow without the formation of air-entraining vortices.