CFD Modeling of a Storm-Water Hydrodynamic Separator

Abstract

Proliferation of manufactured unit operations to separate particulate matter (PM) transported in storm water has generated interest in modeling of such units beyond conventional “% removal” and “black-box” type evaluations. One such unit operation is a screened hydrodynamic separator (HS) combining settling and to a lesser extent inertial separation by means of an annular static screen. However, performance and mechanistic evaluations of HS units are challenged by loadings with wide PM particle size distributions (PSDs) at a range of flow rates. Wastewater-based methods such as total suspended solids (TSS) and auto samplers further challenge such evaluations. This study utilized computational fluid dynamics (CFD) to model PM separation by a HS coupled with measured PSDs, flow rates [1–125% of hydraulic capacity