Reynolds number and geometry effects in laminar axisymmetric isothermal counterflows

Handle URI:
http://hdl.handle.net/10754/622692
Title:
Reynolds number and geometry effects in laminar axisymmetric isothermal counterflows
Authors:
Scribano, Gianfranco; Bisetti, Fabrizio ( 0000-0001-5162-7805 )
Abstract:
The counterflow configuration is a canonical stagnation flow, featuring two opposed impinging round jets and a mixing layer across the stagnation plane. Although counterflows are used extensively in the study of reactive mixtures and other applications where mixing of two streams is required, quantitative data on the scaling properties of the flow field are lacking. The aim of this work is to characterize the velocity and mixing fields in isothermal counterflows over a wide range of conditions. The study features both experimental data from particle image velocimetry and results from detailed axisymmetric simulations. The scaling laws for the nondimensional velocity and mixture fraction are obtained as a function of an appropriate Reynolds number and the ratio of the separation distance of the nozzles to their diameter. In the range of flow configurations investigated, the nondimensional fields are found to depend primarily on the separation ratio and, to a lesser extent, the Reynolds number. The marked dependence of the velocity field with respect to the separation ratio is linked to a high pressure region at the stagnation point. On the other hand, Reynolds number effects highlight the role played by the wall boundary layer on the interior of the nozzles, which becomes less important as the separation ratio decreases. The normalized strain rate and scalar dissipation rate at the stagnation plane are found to attain limiting values only for high values of the Reynolds number. These asymptotic values depend markedly on the separation ratio and differ significantly from the values produced by analytical models. The scaling of the mixing field does not show a limiting behavior as the separation ratio decreases to the smallest practical value considered.
KAUST Department:
Clean Combustion Research Center
Citation:
Scribano G, Bisetti F (2016) Reynolds number and geometry effects in laminar axisymmetric isothermal counterflows. Physics of Fluids 28: 123605. Available: http://dx.doi.org/10.1063/1.4972238.
Publisher:
AIP Publishing
Journal:
Physics of Fluids
Issue Date:
29-Dec-2016
DOI:
10.1063/1.4972238
Type:
Article
ISSN:
1070-6631; 1089-7666
Sponsors:
The research reported in this publication was supported by the King Abdullah University of Science and Technology (KAUST). Gianfranco Scribano performed part of this work while holding a postdoctoral appointment within the Clean Combustion Research Center at KAUST.
Additional Links:
http://aip.scitation.org/doi/10.1063/1.4972238
Appears in Collections:
Articles; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorScribano, Gianfrancoen
dc.contributor.authorBisetti, Fabrizioen
dc.date.accessioned2017-01-15T13:40:36Z-
dc.date.available2017-01-15T13:40:36Z-
dc.date.issued2016-12-29en
dc.identifier.citationScribano G, Bisetti F (2016) Reynolds number and geometry effects in laminar axisymmetric isothermal counterflows. Physics of Fluids 28: 123605. Available: http://dx.doi.org/10.1063/1.4972238.en
dc.identifier.issn1070-6631en
dc.identifier.issn1089-7666en
dc.identifier.doi10.1063/1.4972238en
dc.identifier.urihttp://hdl.handle.net/10754/622692-
dc.description.abstractThe counterflow configuration is a canonical stagnation flow, featuring two opposed impinging round jets and a mixing layer across the stagnation plane. Although counterflows are used extensively in the study of reactive mixtures and other applications where mixing of two streams is required, quantitative data on the scaling properties of the flow field are lacking. The aim of this work is to characterize the velocity and mixing fields in isothermal counterflows over a wide range of conditions. The study features both experimental data from particle image velocimetry and results from detailed axisymmetric simulations. The scaling laws for the nondimensional velocity and mixture fraction are obtained as a function of an appropriate Reynolds number and the ratio of the separation distance of the nozzles to their diameter. In the range of flow configurations investigated, the nondimensional fields are found to depend primarily on the separation ratio and, to a lesser extent, the Reynolds number. The marked dependence of the velocity field with respect to the separation ratio is linked to a high pressure region at the stagnation point. On the other hand, Reynolds number effects highlight the role played by the wall boundary layer on the interior of the nozzles, which becomes less important as the separation ratio decreases. The normalized strain rate and scalar dissipation rate at the stagnation plane are found to attain limiting values only for high values of the Reynolds number. These asymptotic values depend markedly on the separation ratio and differ significantly from the values produced by analytical models. The scaling of the mixing field does not show a limiting behavior as the separation ratio decreases to the smallest practical value considered.en
dc.description.sponsorshipThe research reported in this publication was supported by the King Abdullah University of Science and Technology (KAUST). Gianfranco Scribano performed part of this work while holding a postdoctoral appointment within the Clean Combustion Research Center at KAUST.en
dc.publisherAIP Publishingen
dc.relation.urlhttp://aip.scitation.org/doi/10.1063/1.4972238en
dc.rightsThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in Scribano, G. and Bisetti, F., 2016. Reynolds number and geometry effects in laminar axisymmetric isothermal counterflows. Physics of Fluids, 28(12), p.123605 and may be found at http://aip.scitation.org/doi/10.1063/1.4972238.en
dc.titleReynolds number and geometry effects in laminar axisymmetric isothermal counterflowsen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.identifier.journalPhysics of Fluidsen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Mechanical, Materials and Manufacturing Engineering, University of Nottingham Malaysia Campus, Jalan Broga, Semenyih, Selangor Darul Ehsan, 43500, Malaysiaen
dc.contributor.institutionDepartment of Aerospace Engineering and Engineering Mechanics, University of Texas at Austin, Austin, TX, 78712-1085, United Statesen
kaust.authorBisetti, Fabrizioen
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