Numerical investigation of air vent technique to the outflow discharge characteristic of siphon spillways

Abstract

    This paper represents the numerical investigation of discharge characteristics of siphon spillways in application to simulate the outflow of reservoirs. Siphon spillways have simple structures and large outflow discharges, but it is difficult to control their outflow discharges. The air vent technique is applied to control the air quantities controlled inside the siphon, then it can control the desired outflow discharges and avoid the flood disaster at the spillway downstream. The simulations show that the more air quantities controlled
inside siphons are, the less outflow discharges are. Depending on the water head, the outflow discharges vary in the range between the outflow discharges of the no air case and of the full air case