New approach to modeling particle transport in CFD to determine optimal retention in stormwater sedimentation tanks

Overview & Synopsis

Stormwater sedimentation tanks are still the predominant method of treating stormwater runoff, although their performance does not meet increased demands. To minimize the discharge of pollutants, they should be optimized. Numerical flow simulations offer the possibility to calculate the retention of TSS (Total Suspended Solids) in the tanks to subsequently design optimization proposals. For this purpose, the particle trajectories are calculated in CFD (Computational Fluid Dynamics) using the Discrete Phase Model. Likewise, the retention of the particles is determined. However, the approaches described in the literature for this purpose overestimate the efficiencies. Therefore, a further developed approach for the calculation of particle transport in the tank is presented here. This approach allows a valid determination of the efficiencies for different tank configurations and different particle properties.