Analysis of Non-Iterative Methods and Proposal of a New One for Pressure-Driven Snapshot Simulations with EPANET

Abstract

This paper compares different recently proposed methods for pressure-driven snapshot simulations of water distribution networks using the EPANET software interface and proposes a new one. The proposed method is based on the insertion of a sequence of devices consisting of a General Purpose Valve (GPV), a fictitious junction, a reach with a check valve and a reservoir at each water demand node. The proposed method differs from other methods previously proposed in the literature – and similarly based on the insertion of sequences of devices consisting of a valve and a reservoir or emitter – in that it uses a GPV; more specifically, for this valve the user can fix the relationship between outflow discharge (or the flow delivered to users) and the available pressure head at the node, thus allowing for a flexible representation of the relationship between these two parameters, whereas with the other methods this relationship remains fixed, based on the structure of the sequence of devices used. Practical applications to three different real-life cases show the unreliability and limits, in terms of accuracy, of some of the methods previously proposed in the literature. They also show, by contrast, the validity of the new method, which has proven to be reliable and accurate, as well as flexible, since it enables any relationship to be defined between the delivered flow and available head.