Turbid density current venting through reservoir outlets

Abstract

The planning and design of an outlet operation by releasing a turbid density current from a reservoir requires accurate prediction of outflow concentration for sluicing sediment through outlet structures. This study investigates outflow concentration and venting efficiency through reservoir outlets in a reservoir sluicing operation related to turbid density current. A 3D numerical model is employed to simulate a venting operation for a turbid density current in typhoon-induced flood events. A simple and efficient formula derived from theoretical analysis with experimental data is proposed for estimating outflow concentration and venting efficiency. By adopting the proposed formula to avoid time-consuming calculation using the 3D numerical model, the estimated outflow concentration and venting efficiency through reservoir outlets have shown good agreement with the measured and simulated results in typhoon flood events. This demonstrates that the formula provides an efficient approach for engineering practice in real-time reservoir venting operations.