AWWA ACE94268

A comparison is made between the formulation and computational performance of two different methods for modeling water quality in drinking water distribution systems. The time-driven method is Eulerian in nature and moves water between fixed-sized volume segments in pipes as time is advanced in uniform increments. The event-driven method is Lagrangian in nature. It follows the positions of variable-sized parcels of water through a pipe network and only updates conditions when a new parcel reaches a junction node. Both methods were encoded into an existing network simulation model and run on several actual distribution systems of varying size under equal accuracy tolerances. Results showed that predictions from both models were quite close and that they both were capable of describing observed water quality behavior. The event-driven method was better able to track sharp concentration fronts and had faster solution times when high accuracy was required. It did, however, require more memory usage.