Fluid flow in a spiral microfluidic duct

dc.contributor.authorHarding, B.
dc.contributor.authorStokes, Y.
dc.date.issued2018
dc.descriptionPublished online 30 April 2018
dc.description.abstractWe consider the steady, pressure driven flow of a viscous fluid through a microfluidic device having the geometry of a planar spiral duct with a slowly varying curvature and height smaller than width. For this problem, it is convenient to express the Navier–Stokes equations in terms of a non-orthogonal coordinate system. Then, after applying appropriate scalings, the leading order equations admit a relatively simple solution in the central region of the duct cross section. First-order corrections with respect to the duct curvature and aspect ratio parameters are also obtained for this region. Additional correction terms are needed to ensure that no slip and no penetration conditions are satisfied on the side walls. Our solutions allow for a top wall shape that varies with respect to the radial coordinate which allows us to study the flow in a variety of cross-sectional shapes, including trapezoidal-shaped ducts that have been studied experimentally. At leading order, the flow is found to depend on the local height and slope of the top wall within the central region. The solutions are compared with numerical approximations of a classical Dean flow and are found to be in good agreement for a small duct aspect ratio and a slowly varying and small curvature. We conclude that the slowly varying curvature typical of spiral microfluidic devices has a negligible impact on the flow in the sense that locally the flow does not differ significantly from the classical Dean flow through a duct having the same curvature.
dc.description.statementofresponsibilityBrendan Harding and Yvonne Stokes
dc.identifier.citationPhysics of Fluids, 2018; 30(4):042007-1-042007-19
dc.identifier.doi10.1063/1.5026334
dc.identifier.issn1070-6631
dc.identifier.issn1089-7666
dc.identifier.orcidHarding, B. [0000-0002-6755-9998]
dc.identifier.orcidStokes, Y. [0000-0003-0027-6077]
dc.identifier.urihttp://hdl.handle.net/2440/112421
dc.language.isoen
dc.publisherAmerican Institute of Physics
dc.relation.granthttp://purl.org/au-research/grants/arc/DP160102021
dc.rightsCopyright the authors. Published by AIP Publishing.
dc.source.urihttps://doi.org/10.1063/1.5026334
dc.titleFluid flow in a spiral microfluidic duct
dc.typeJournal article
pubs.publication-statusPublished

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