Arfaie, A, Burns, AD, Dorrell, RM et al. (3 more authors) (2014) Optimised mixing and flow resistance during shear flow over a rib roughened boundary. International Communications in Heat and Mass Transfer, 58. 54 - 62. ISSN 0735-1933
Abstract
A series of numerical investigations has been performed to study the effect of lower boundary roughness on turbulent flow in a two-dimensional channel. The roughness spacing to height ratio, w/k, has been investigated over the range 0.12 to 402 by varying the horizontal rib spacing. The square roughness elements each have a cross-sectional area of (0.05 H)2, where H is the full channel height. The Reynolds number, Reτ is fixed based on the value of the imposed pressure gradient, dp/dx, and is in the range 6.3 × 103 − 4.5 × 104. A Reynolds Averaged Navier–Stokes (RANS) based turbulence modelling approach is adopted using a commercial CFD code, ANSYS-CFX 14.0. Measurements of eddy viscosity and friction factor have been made over this range to establish the optimum spacings to produce maximum turbulence enhancement, mixing and resistance to flow. These occur when w/k is approximately 7. It is found that this value is only weakly dependent on Reynolds number, and the decay rate of turbulence enhancement as a function of w/k ratio beyond this optimum spacing is slow. The implications for heat transfer design optimisation and particle transport are considered.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2014, Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in International Communications in Heat and Mass Transfer. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in International Communications in Heat and Mass Transfer, 58, 2014, 10.1016/j.icheatmasstransfer.2014.08.005 |
Keywords: | Turbulent flow; Roughness; CFD |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 24 Sep 2014 10:35 |
Last Modified: | 21 Jan 2018 18:12 |
Published Version: | http://dx.doi.org/10.1016/j.icheatmasstransfer.201... |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.icheatmasstransfer.2014.08.005 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:80601 |