Dimensionless approach for the design of flushing gates in sewer channels

The various hydraulic and environmental problems related to the accumulation of solids have recently drawn increasingly attention to deposits in the management of sewer systems. Among the mechanical and hydraulic devices used for deposit removal, hydraulic flushing gates have proved to be a cost-effective solution and have been adopted in several sewer networks. This paper reports the results of an investigation on the scouring performance of flushing waves produced by hydraulic flushing gates. A numerical model based on the De Saint Venant–Exner equations in dimensionless form was validated by using data derived from laboratory experiments and was then utilized in this investigation. Simulations were carried out considering various values of the dimensionless parameters involved in the analysis, in order to obtain indications for the design and positioning of flushing devices in sewer channels. The problem of optimal flushing frequency was also investigated.