title: Separation efficiency of a hydrodynamic separator using a 3D computational fluid dynamics multiscale approach.
abstract: The aim of this study is to investigate the use of computational fluid dynamics (CFD) to predict the solid separation efficiency of a hydrodynamic separator. The numerical difficulty concerns the discretization of the geometry to simulate both the global behavior and the local phenomena that occur near the screen. In this context, a CFD multiscale approach was used: a global model (at the scale of the device) is used to observe the hydrodynamic behavior within the device; a local model (portion of the screen) is used to determine the local phenomena that occur near the screen. The Eulerian-Lagrangian approach was used to model the particle trajectories in both models. The global model shows the influence of the particles' characteristics on the trapping efficiency. A high density favors the sedimentation. In contrast, particles with small densities (1,040 kg/m(3)) are steered by the hydrodynamic behavior and can potentially be trapped by the separator. The use of the local model allows us to observe the particle trajectories near the screen. A comparison between two types of screens (perforated plate vs expanded metal) highlights the turbulent effects created by the shape of the screen.
authors.affiliation: National School for Water and Environmental Engineering of Strasbourg (ENGEES), ICube (University of Strasbourg, CNRS, INSA of Strasbourg, ENGEES), Mechanics Department, Fluid Mechanics Team, ENGEES, 1 quai Koch, BP 61039, 67070 Strasbourg cedex, France E-mail: vivien.schmitt@engees.unistra.fr.
authors.forename: Vivien
authors.initials: V
authors.lastname: Schmitt
authors.affiliation: National School for Water and Environmental Engineering of Strasbourg (ENGEES), ICube (University of Strasbourg, CNRS, INSA of Strasbourg, ENGEES), Mechanics Department, Fluid Mechanics Team, ENGEES, 1 quai Koch, BP 61039, 67070 Strasbourg cedex, France E-mail: vivien.schmitt@engees.unistra.fr.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Dufresne
authors.affiliation: National School for Water and Environmental Engineering of Strasbourg (ENGEES), ICube (University of Strasbourg, CNRS, INSA of Strasbourg, ENGEES), Mechanics Department, Fluid Mechanics Team, ENGEES, 1 quai Koch, BP 61039, 67070 Strasbourg cedex, France E-mail: vivien.schmitt@engees.unistra.fr.
authors.forename: Jose
authors.initials: J
authors.lastname: Vazquez
authors.affiliation: National School for Water and Environmental Engineering of Strasbourg (ENGEES), ICube (University of Strasbourg, CNRS, INSA of Strasbourg, ENGEES), Mechanics Department, Fluid Mechanics Team, ENGEES, 1 quai Koch, BP 61039, 67070 Strasbourg cedex, France E-mail: vivien.schmitt@engees.unistra.fr.
authors.forename: Martin
authors.initials: M
authors.lastname: Fischer
authors.affiliation: Hydroconcept, ZA Trappes Elancourt, 46 avenue des frères Lumière, 78190 Trappes, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Morin
mesh_terms: D057446:Hydrodynamics; D014873:Water Pollutants / Q000302:isolation & purification*; D018508:Water Purification / Q000295:instrumentation*
chemical_list: D014873:Water Pollutants