Water distribution systems: Using linearized hydraulic equations within the framework of ranking-based optimization algorithms to improve their computational efficiency

With reference to water distribution system optimization problems in which the search algorithm is “guided” by a ranking of the possible solutions based on a system performance indicator, the authors propose replacing the standard hydraulic simulator with a simpler simulator based on linearized energy balance equations. This simulator enables each solution to be assigned a value of the performance indicator whose ranking closely approximates the ranking that would be obtained if the correct hydraulic simulator were used, while at the same time ensuring significant reductions in computational times. The results obtained in addressing two different problems applied to real water distribution systems, namely, identification of the optimal placement of flow meters in a DMA and multi-objective design of a water distribution system, show that using a linearized hydraulic simulator can lead rapidly to a near-optimal solution(s), which can then be better quantified using the correct hydraulic simulator.