COMPUTATIONAL MODELING OF A VORTEX CSO STRUCTURE

Vortex combined sewer overflow (CSO) structures with a peripheral spil l weir are sometimes used within UK sewerage systems for the preventio n of flooding and the retention of pollutants within the sewer system. The velocity distribution within such a CSO chamber has been simulate d using the 3D mathematical model FLUENT. Similarly the particle track ing routine of FLUENT has been utilised to predict the trajectory and final destination (treatment or spill) or individual particles with kn own size and terminal velocity which were introduced within the inflow to the chamber. From this data it has been possible to predict the so lids separation retention efficiency for these particles and the resul ts have been compared with previously published experimental data. Som e agreement was observed between the two sets of results. The paper is concluded by a discussion concerning the capability and limitations o f the FLUENT model to predict the hydraulic and pollutant retention pe rformance of a Vortex CSO chamber.