DETERMINATION OF CRITICAL SUBMERGENCE DEPTH AT HORIZONTAL INTAKES UNDER ASYMMETRIC FLOW CONDITIONS

The purpose of the present study is to investigate the hydraulic conditions of air-entraining vortices under asymmetrical flow conditions and derive a general expression to determine the critical submergence depth required for the formation of these vortices at horizontal intake pipes. A series of experiments were conducted in a model composed of a concrete reservoir and intake pipe which was mounted horizontally to the reservoir. Three pipes of different diameters were tested with adjustable plexiglass side walls to investigate the effect of side-wall clearances on the critical submergence depth. Based on the experimental results obtained from a wide range of side-wall clearances and discharges, empirical equations for the critical submergence depth were derived and compared with Gordon's (1970) relationship.