A Quick Survey of the Most Vulnerable Areas of a Water Distribution Network Due to Transients Generated in a Service Line: A Lagrangian Model Based on Laboratory Tests

Abstract

This paper analyses the propagation and mechanisms of interaction of a pressure wave in a looped water distribution network by means of laboratory and numerical tests. Transients are generated by the complete and fast closure of a valve, simulating an end-user maneuver, located at the downstream end section of a service line. The adequate length of the service line allows capturing each single pressure wave inserted into the network. The executed tests and successive analysis by means of a Lagrangian model (LM) highlight the effect of the network topology and the location of the transient generation point but in a more expeditious way with respect to the use of a complete transient model. The most excited part of the system is the one in close proximity of the end-user and then the corresponding service line. Within the network, pressure waves accumulate in the areas with the smallest diameter pipes. By means of the refined LM—which is able to capture the pressure extreme values occurring in the first phases of the transient—the vulnerability maps of the network are provided. Such maps identify the nodes subjected to the most severe pressure waves in terms of both frequency and amplitude. The exposure level to transients of each node is synthesized by the value of the vulnerability index proposed in this paper.

Extending the Application of Connectivity Metrics for Characterizing the Dynamic Behavior of Water Distribution Networks

“…Some studies have shown that the response of the WDN to these forcing factors depends on its characteristics and, in particular, on the topological structure (i.e., network connectivity) (Meniconi et al., 2022a, 2022b) as well as the presence of elements such as dead ends (Meniconi et al., 2018, 2021) and on diameter and material of pipes (Ellis, 2008; Karney & McInnis, 1990; Starczewska et al., 2014). Thus, each WDN is characterized by a different transient response in the face of a forcing factor.…”

“…Recently, there has been evidence that users' activity (Marsili et al, 2021), that is, the opening and closing of domestic devices, can also result in the generation of pressure waves of small entity but occurring almost continuously over the day, producing deterioration that tends to worsen over time and increase failure rate (Rezaei et al, 2015). Some studies have shown that the response of the WDN to these forcing factors depends on its characteristics and, in particular, on the topological structure (i.e., network connectivity) (Meniconi et al, 2022a(Meniconi et al, , 2022b as well as the presence of elements such as dead ends (Meniconi et al, 2018(Meniconi et al, , 2021 and on diameter and material of pipes (Ellis, 2008;Karney & McInnis, 1990;Starczewska et al, 2014). Thus, each WDN is characterized by a different transient response in the face of a forcing factor.…”