Quantification of the Head-Outflow Relationship for Pressure-Driven Analysis in Water Distribution Networks

Pressure-driven analysis (PDA) has been applied as a general analysis technique because it can simulate a real water supply network based on reasonable theoretical assumptions. However, to provide reliable PDA results, it is necessary to determine a head-outflow relationship (HOR) expression that enables the calculation of the available outflow at each node at certain pressure intervals. In this study, experiment-based HOR quantification methods for PDA were proposed and the characteristics of HOR were first confirmed under various experimental conditions. To identify the hydraulic behaviors of WDNs (water distribution networks) for situations that are practically infeasible and cannot be reproduced, a WDN model was fabricated. Normal and abnormal conditions that cannot be immediately measured were configured to identify the relationship between the head and outflow under individual conditions via the WDN model. The goodness-of-fit of the various HORs were identified using the data from each node. Appropriate parameter values were defined and PDA uncertainty was confirmed. Finally, the HORs obtained through the experiments were selected instead of assumed HORs. Therefore, this study not only improves the reliability of PDA results, but also provides workers with an improved understanding of the correlation between heads and outflows at WDNs.