Characteristics of water hammer induced by valve-valve systems

Characteristics of water hammer induced by valve-valve systems are studied numerically. Instead of the conventional reservoir-valve systems, valve-valve systems considered include two valves which close simultaneously and which close respectively with specific time delays. Under these settings, the pressure head and the fluid field of the flow are simulated and observed. The characteristics of wave front are discussed and analyzed with the fluid field. Finally, the pressure head history and average velocity history are given to indicate the effects of time delay of the closure of the entrance valve.