Modeling and Simulations of Flow Pattern and Chlorine Distribution in A Potable Water Service Reservoir of Singapore

摘要

The existing reported numerical studies of service reservoir are fairly limited to steady flow simulations with a fixed water level. To overcome the challenge of tracking water level variations for dynamic service condition, both multiphase analysis and dynamic mesh methods are implemented in this study for turn over service condition. The results of multiphase analysis verify that the sloshing effect is minimal. It is therefore valid to assume that the water-air interface would remain as a horizontal plane. The dynamic mesh method is then used to track the water level variations with reduced computational cost. The predicted chlorine concentration at the outlet matches well with that of on-site measurement. The second simulation case studies the flow and chlorine concentration distribution under a common service condition. It reveals short-circuiting pattern of the flow. The subsequent formation of dead zones implies poor lateral and moderate vertical mixings, which result in nonuniform chlorine concentration in the service reservoir.