Flow field prediction in full-scale Carrousel oxidation ditch by using computational fluid dynamics

摘要

In order to optimize the flow field in a full-scale Carrousel oxidation ditch with many sets ofndisc aerators operating simultaneously, an experimentally validated numerical tool, based onncomputational fluid dynamics (CFD), was proposed. A full-scale, closed-loop bioreactorn(Carrousel oxidation ditch) in Ping Dingshan Sewage Treatment Plant in Ping Dingshan City, anmedium-sized city in Henan Province of China, was evaluated using CFD. Moving wall modelnwas created to simulate many sets of disc aerators which created fluid motion in the ditch.nThe simulated results were acceptable compared with the experimental data and the followingnresults were obtained: (1) a new method called moving wall model could simulate the flownfield in Carrousel oxidation ditch with many sets of disc aerators operating simultaneously.nThe whole number of cells of grids decreased significantly, thus the calculation amountndecreased, and (2) CFD modeling generally characterized the flow pattern in the full-scale tank.n3D simulation could be a good supplement for improving the hydrodynamic performance innoxidation ditch designs.