Natural convection heat transfer and fluid flow in a thermal chimney with multiple horizontally-alighned cylinders

Ma, H., He, L., Yu, G. and Yu, Z. (2022) Natural convection heat transfer and fluid flow in a thermal chimney with multiple horizontally-alighned cylinders. International Journal of Heat and Mass Transfer, 183(Part C), 122239. (doi: 10.1016/j.ijheatmasstransfer.2021.122239)

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Abstract

To address the scarcity of natural convection research for the tube array with three or more columns of horizontally-aligned cylinders, this paper conducts RANS/URANS simulations for multiple cylinder columns in one or two rows, validated by particle-image velocimetry and heat transfer measurements. Parametric study with varying horizontal and vertical pitches is implemented by RANS with transition SST model. Key findings are then substantiated and examined by URANS. It is found that the horizontal pitch influences the balance between the chimney effect and the blockage effect, thus has an optimum with respect to the natural draft velocity. For all the vertical distances computed in the two-row thermal chimney model, the flow pattern stays in a plume-dominant mode at the large horizontal pitch and a chimney-dominant mode at the small horizontal pitch. Interestingly, at the intermediate horizontal pitch (pitch/diameter≈2.5), the flow pattern switches from plume-dominant to chimney-dominant over a minor increase of the vertical pitch (from 4.5 to 6 diameters), leading to significant augmentation in natural draft velocity and heat transfer on cylinder surfaces. This distinct thermo-flow behavior, identified for the first time to the authors’ knowledge, may be harnessed to improve the performance of passive heat exchangers.

Item Type:Articles
Additional Information:The authors would like to thank the financial support from EPSRC Global Challenges Research Fund (EP/P028829/1). The first author would also like to acknowledge funding from National Natural Science Foundation of China (52106050), Natural Science Foundation of Shanghai (Foundation of Shanghai (21ZR1431800) and Shanghai Science and Technology Commission Young Talent Sailing Program (20YF1419100).
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Yu, Dr Guopeng and Yu, Professor Zhibin
Creator Roles:
Yu, G.Validation, Data curation, Visualization
Yu, Z.Supervision, Project administration, Funding acquisition
Authors: Ma, H., He, L., Yu, G., and Yu, Z.
College/School:College of Science and Engineering > School of Engineering > Systems Power and Energy
Journal Name:International Journal of Heat and Mass Transfer
Publisher:Elsevier
ISSN:0017-9310
ISSN (Online):1879-2189
Published Online:22 November 2021
Copyright Holders:Copyright © 2021 Elsevier Ltd.
First Published:First published in International Journal of Heat and Mass Transfer 183(Part C): 122239
Publisher Policy:Reproduced in accordance with the publisher copyright policy

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
300663Geothermally Sourced Power and Freshwater Generation for Eastern AfricaZhibin YuEngineering and Physical Sciences Research Council (EPSRC)EP/P028829/1ENG - Systems Power & Energy