title: Optimization and evaluation of radially interconnected versus bifurcating flow distributors using computational fluid dynamics modelling.
abstract: Two main groups of flow distributors, viz. "bifurcating distributors" (BF) and "radially interconnected distributors" (RI), as well as some hybrid distributors were investigated. Computational fluid dynamics was used to evaluate the performance of the distributors and to establish the design yielding the most uniform velocity field and the smallest variance for the bands emerging from the distributor. A minimum channel width of 100 μm was considered to allow the use of micro-milling techniques for chip fabrication. The main factors that influenced the values of band variances were identified. The performance of the distributors was found to correlate most strongly with the volume of the flow distributors. The separation bed should be positioned immediately after, but not against the flow distributor. It was concluded that BF distributors perform best in terms of band variance. The values of band variances for the BF distributor decreased with increasing angle between bifurcation branches and the lowest value of about 0.01 mm(2) was found for α=175°. Both BF and RI flow distributors were found to perform reasonably well when imperfections were present in the structure. However, severe blockages (exceeding 75% of the cross-sectional area and length) of channels in, especially, BF flow distributors may jeopardize their performance.
authors.affiliation: Analytical Chemistry Group, Van't Hoff Institute for Molecular Sciences, University of Amsterdam, PO Box 94157, 1090 GD Amsterdam, The Netherlands. Electronic address: e.davydova@uva.nl.
authors.forename: E
authors.initials: E
authors.lastname: Davydova
authors.affiliation: Vrije Universiteit Brussel (VUB), Department of Chemical Engineering, 1050 Brussels, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Deridder
authors.affiliation: Vrije Universiteit Brussel (VUB), Department of Chemical Engineering, 1050 Brussels, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Eeltink
authors.affiliation: Vrije Universiteit Brussel (VUB), Department of Chemical Engineering, 1050 Brussels, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: Desmet
authors.affiliation: Analytical Chemistry Group, Van't Hoff Institute for Molecular Sciences, University of Amsterdam, PO Box 94157, 1090 GD Amsterdam, The Netherlands.
authors.forename: P J
authors.initials: PJ
authors.lastname: Schoenmakers
mesh_terms: D057446:Hydrodynamics; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008962:Models, Theoretical
keywords: Chip-based separations; Computational fluid dynamics; Flow distributors; Microfluidics; Robust performance