Optimal Design for Shock Damper with Genetic Algorithm to Control Water Hammer Effects in Complex Water Distribution Systems

In this paper, the optimal design of a shock damper and its parameters along with the layout for controlling water hammer effects in water distribution systems (WDS) will be investigated. The shock damper and its governing equations are introduced, and then complex network (networks with loop and branching) analysis is performed during the occurrence of a water hammer. Because of the multiple design parameters for the shock damper and the complexity of WDS transient analysis, a standard optimization problem is defined with maximum safety as the objective function. The problem constraints are the network analysis equations in the event of a water hammer. Also, other constraints consist of the maximum and minimum range of the allowable head and values of the design parameters for the shock damper. To solve the problem, a genetic algorithm is used, and a flow chart of the problem-solving design with the genetic algorithm is also provided. To investigate the efficiency and the effect of the optimal design of the shock damper, two real water distribution networks are considered, which include a gravity network and a pumping network. To create a water hammer occurrence in the first network, the amount of discharge in one of the nodes is suddenly increased, while in the second network, one of the control valves is closed suddenly. These events lead to the occurrence of a significant water hammer in each system, resulting in both positive and negative waves and water column separation phenomena. The results show the high effectiveness of the optimal shock damper design in controlling the effects of transient flows in real water distribution systems, thereby increasing those systems' effectiveness.