General Hydrodynamic Model for Sewer/Channel Network Systems

A general hydrodynamic numerical model for sewer/channel networks is presented. The Priessmann Slot assumption is adopted to extend open channel flow equations to closed conduits under surcharged conditions. The “superlink” algorithm with a staggered grid, implicit scheme is developed to improve the stability and speed of the computation. The SUPERLINK computer model was established without omission of any terms in the St. Venant equations under both subcritical and supercritical flow conditions. The model reduces the order of the sparse matrix equation so that a considerable savings in computational effort is achieved. The numerical experiments show that the model is robust and reliable, and produces consistent results under different grid setups. The application to a large looped sewer network shows a reasonable agreement with field measurement. A comparison between the results from the SUPERLINK and the SWMM EXTRAN model demonstrates that while maintaining the computational stability and accuracy, the computation can be sped up using the SUPERLINK algorithm for the sewer network system, which experienced a wide variety of hydrodynamic conditions.