Hydraulic physical scale modeling of a complex sewage system

Large urban sewage systems are usually provided with complex hydraulic structures, characterized by geometrical particularities. Consequently, considering the extreme turbulent state of the water currents and their free surface shape, the flow associated to such structures is very diverse and unique. Under these circumstances, in order to analyze the intricate involved phenomena, the only feasible approach is the physical scale modeling. Starting from the base principles, the paper reveals the efforts developed by the authors in order to model at reduced scale what really happens in some of the key elements that are part of the sewage system of the Bucharest municipality. Beside a better understanding of the hydraulic phenomena that are taking place, the final goal of these studies was to conceive a technical solution for improving the flow in both dry and rainy conditions.