Experimental and Numerical Investigation of Flow Hydraulics and Pipe Geometry on Leakage Behaviour of Laboratory Water Network Distribution Systems
Keywords:water distribution network, water leakage, solenoid valve, computational fluid dynamics (CFD), Matlab
As the leakage behaviour of water distribution network is considered a critical and life-threatening issue, so this behaviour of water distribution network systems has been investigated experimentally and numerically, based on the effects of different positions and flow rates of the leakage outlets, and taking into consideration the flow hydraulics and pipe geometry. A laboratory model of the actual water distribution network studied was constructed. The laboratory water distribution network model is horizontal and has 16 loops with a total length of 30m in different diameters. The leakage position in the laboratory water distribution network was altered between main, sub-main, and branch pipelines with different flow rates. The characteristics of the ideal laboratory water distribution network with no-leakage were first studied; and the water distribution network system parameters were calculated theoretically using the Hardy-Cross method with seven iterations. The studied water distribution network system was simulated using computational fluid dynamics technique, Ansys. Fluent 18.2. The aim was to modify the old water distribution network by sensing the pressure values using dispersed pressure sensors. Also, from the pressure map of the laboratory water distribution network, the leakage position, if any, could be located. Depending on the sensed pressure, the control circuit was programmed to close the corresponding solenoid valves. The leakage flow rates were 0.1, 0.25, and 0.4 L/s; and changed between the main and sub-main pipes. The maximum pressure drop was around 500pa at the node directly preceding the leakage point at leakage flow rate 0.4 L/s. The performance of the used solenoid valve was simulated using the Matlab-Simulink technique. The simulation results showed the response to stepdown control signal was over-damped with steady state error of 2% and settling time of 0.6 s.