Sensitivity Analysis of Hydraulic Parameters on Contaminant Intrusion in Transient Conditions

Water quality degrades due to the complex physical, chemical and biological processes passing through the transmission lines. 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. The purpose of this study is to determine the effect of hydraulic parameters on the duration of negative pressure and the magnitude of negative pressure and subsequently the volume of contaminant intrusion in a reservoir-pipe-valve system with leakage. 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 senarios.The results are provided in a number of graphs which quantify the influence of each system parameter. The results indicate that the volume of contaminant intrusion is mostly dominated by the amount of negative pressure at leak. The amount of intrusion is investigated via several case studies..The reservoir pressure head, fluid velocity inside the pipe, the wave speed, the pipe diameter, the leak diameter and the leakage location are respectively the effective hydraulic parameters on contaminant intrusion. Investigation of the interaction of these factors in the volume of contaminant intrusion can be considered as a subject for future research.