High Fidelity Computational Fluid Dynamics for Mixing in Water Distribution Systems

Abstract

Network simulation models for water distribution systems typically assume the mixing at pipe intersections is complete and instantaneous. More accurate characterizations of chemical or biological agent transport may be required to efficiently identify, control and mitigate the spread of harmful agents and to protect critical components within the network. Recent experimental data have shown that mixing is incomplete at pipe junctions (pipe crosses and tees). Numerical simulations of these experiments have been performed using simplified turbulence methods. In the present study, simulations of mixing in pipe junctions are performed using the high-fidelity Large Eddy Simulation (LES) approach to fully resolve the mixing behavior. Simulation results show unsteady mixing behavior at the fluid interface due to shear layer instabilities. These high-fidelity results will be used to develop a lower fidelity model for mixing at pipe junctions. This paper was presented at the 8th Annual Water Distribution Systems Analysis Symposium which was held with the generous support of Awwa Research Foundation (AwwaRF).