The present experimental study focuses on the characterization of complex mixing phenomena at pipe intersections within pressurized water distribution networks. To examine the complete mixing assumption at a cross junction, a series of experiments were conducted in the turbulent regime ͑R Ͼ 10,000͒. The experimental setup consists of a cross junction with various sensors, pumps, and a data acquisition system to accurately measure solute concentration. Selected experimental results are compared to computational fluid dynamics ͑CFD͒ results. In addition, the water quality model associated with a standard water distribution network simulator ͑EPANET͒ was reevaluated based on CFD and experimental data. Corrections based on experimental results are incorporated into EPANET ͑AZRED 1.0͒ for use in a case study. The study concludes that the complete mixing assumption can potentially create considerable errors in water quality modeling. Further, severe errors are likely to occur in systems with many cross type junctions due to bifurcation of the incoming flows.

No abstract

No abstract

Concerns about the security of water distribution systems have lead to increased interest in sensor placement in water distribution systems. Due to the cost of both placing and maintaining these sensors, the number of sensors used must be limited. These constraints make the sensor deployment locations crucial in a water monitoring system. Many studies, based on differing algorithms and objective functions, have sought to determine ways to optimize sensor location. These studies have largely relied on current water quality models that assume perfect mixing at pipe junctions. However, it has been shown that using a water quality model that accounts for imperfect mixing (AZRED) at pipe intersections produces outcomes that differ from those produced by studies that assume perfect mixing and, consequently produces a different scheme for optimal sensor placement. The current work uses a multiobjective approach that relies on the nondominated, sorted algorithm II. The study seeks, first, to contrast the use of the AZRED water-quality model to the use of water quality models that assume perfect mixing, and, second, to propose a more comprehensive approach to sensor placement. By using a simpler objective of optimizing for complete sensor coverage, the study will expand on pervious work that made this comparison. An example network is analyzed using both AZRED and EPANET, and the results are compared.