Enhanced WDN Analysis: Representation of Actual Pipe Connections

The classical assumption of representing the total demand along a pipe as two lumped withdrawals at its terminal nodes is hitherto common. It is a simplification of the network topology which is useful in order to drastically reduce the number of nodes during network simulation. Conversely, this simplification does not preserve pipes' energy balance equation and, for this reason, it is a wrong approximation that could generate large head loss errors. This paper presents an extension of the Global Gradient Algorithm (GGA) which entails a modified GGA permitting the effective introduction of the lumped nodal demands, and without forfeiting a correct pipe head loss, by means of a pipe hydraulic resistance correction.