Interaction of Hydraulic Parameters Affecting The Rate of Contaminant Intrusion in Pipeline Due to Transient Condition

Contaminant intrusion in pipelines is an important mechanism, which may lead to deterioration of the drinking water quality. One of these widely attracted processes is contaminant intrusion due to a transient event. When the negative pressure wave of water hammer reaches a structural deteriorations such as a leakage, it can suddenly sucks pollution from the surrounding area of leakage to the main pipeflow which can in turn endanger public health.In this research, numerical and mathematical modeling of a reservoir-pipe-valve system with leakage has been used to investigate the effect of the interaction of hydraulic parameters on the volume of contamination introduced into the pipelines during the waterhammer. In this study, the Eulerian method of characteristics was used to model the transient flow. The total Volume of Contaminant Parcel (VCPt) from the leakage site taken from Lagrangian solution of the advection equation used as criterion to compare various transient scenarios. In order to provide a better understanding of this phenomenon, in 72 different situations, contaminant intrusion has been investigated. The average rate of contaminant intrusion in the the long viscoelastic pipe line to elastic pipe is equal to 7.2%. This ratio is 49.6% in the case of a short viscoelastic pipeline.The results indicate that the volume of contamination sucked in the viscoelastic pipe in different conditions is less than that of elastic pipe. The results clearly outperform the viscoelastic pipe in preventing contaminant intrusion.