Pressure Flow-Based Algorithms for Pressure-Driven Analysis of Water Distribution Networks

In recent years, pressure-driven analyses of water distribution systems using pressure-flow relationships (PFRs) were shown to be more computationally efficient than those based on flow-pressure relationships (FPRs), such as the widely used Wagner equation and various spline approximations. Using a PFR enhances the convergence properties of the Newton-Raphson method used by most water distribution network (WDN) solvers. This paper derives a new way of incorporating a PFR into the classical Todini and Pilati global gradient algorithm (GGA). The convergence properties of the resulting solution algorithm are compared with those from two other existing PFR algorithms, EPANET 2.2 and the active-set method (ASM), as well as from a conventional flow-pressure-based algorithm on a number of different networks of varying size.