Author(s): Valentina Marsili, Alvisi Stefano, Francipane Antonio, Silvia Meniconi, Bruno Brunone
Keywords: Hydraulic transients; Unsteady flow; Water distribution systems; Field data;
Abstract: Water distribution networks are traditionally modelled, designed and managed assuming steady flow conditions considering at most Extended Period Simulation (EPS) approach. However, water distribution systems are actually subject to unsteady flow phenomena. The resulting pressure oscillations can potentially cause structural damage to the systems as well as water quality problems due to the intrusion of contaminants or untreated water. Consequently, it is crucial to conduct a reliable evaluation of the unsteady flow phenomena in order to assure the pipe system integrity and security. However, examples of experimental analyses of the dynamic behaviour of a real water distribution network are very limited to date and mainly focused on the impact of important operations such as valves or pumps manoeuvres.
This paper shows the results of the monitoring and analysis of the dynamic behaviour of a real water distribution network, Gorino Ferrarese (FE, Italy), under ordinary operational conditions. Both pressure and flow were monitored for two days. The dynamic behaviour of the system is thus characterized by an analysis of the pressure fluctuations in the measurement sections. The analysis highlights that all the system is characterized by some predominant low frequencies, related to the network geometry and characteristics. On the other hand, very short pressure oscillations were observed at the measurement sections: they differ according to both the location of the measurement sections – characterized by different density of user connections – and the time of day. These high-frequency pressure signal components can be related to the system management and user demand.