title: Simple microfluidic stagnation point flow geometries.
abstract: A geometrically simple flow cell is proposed to generate different types of stagnation flows, using a separation flow and small variations of the geometric parameters. Flows with high local deformation rates can be changed from purely rotational, over simple shear flow, to extensional flow in a region surrounding a stagnation point. Computational fluid dynamic calculations are used to analyse how variations of the geometrical parameters affect the flow field. These numerical calculations are compared to the experimentally obtained streamlines of different designs, which have been determined by high speed confocal microscopy. As the flow type is dictated predominantly by the geometrical parameters, such simple separating flow devices may alleviate the requirements for flow control, while offering good stability for a wide variety of flow types.
authors.affiliation: Department of Chemical Engineering, KU Leuven , Celestijnenlaan 200F, Heverlee, Belgium.
authors.forename: Greet
authors.initials: G
authors.lastname: Dockx
authors.affiliation: Department of Chemical Engineering, KU Leuven , Celestijnenlaan 200F, Heverlee, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Verwijlen
authors.affiliation: Department of Chemistry, KU Leuven , Celestijnenlaan 200F, Heverlee, Belgium.
authors.forename: Wouter
authors.initials: W
authors.lastname: Sempels
authors.affiliation: Department of Materials, ETH Zürich , Vladimir-Prelog-Weg 5, HCI H 503, Zürich, Switzerland.
authors.forename: Mathias
authors.initials: M
authors.lastname: Nagel
authors.affiliation: Department of Chemical Engineering, KU Leuven , Celestijnenlaan 200F, Heverlee, Belgium.
authors.forename: Paula
authors.initials: P
authors.lastname: Moldenaers
authors.affiliation: Department of Chemistry, KU Leuven , Celestijnenlaan 200F, Heverlee, Belgium.
authors.forename: Johan
authors.initials: J
authors.lastname: Hofkens
authors.affiliation: Department of Materials, ETH Zürich , Vladimir-Prelog-Weg 5, HCI H 503, Zürich, Switzerland.
authors.forename: Jan
authors.initials: J
authors.lastname: Vermant