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Geometric optimization for the maximum heat transfer density rate from cylinders rotating in natural convection
Dissertation (MEng)--University of Pretoria, 2012.
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University of Pretoria
2013
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| _version_ | 1867613473843707904 |
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| access_status_str | Open Access |
| author2 | Bello-Ochende, Tunde |
| author_browse | Bello-Ochende, Tunde |
| author_facet | Bello-Ochende, Tunde |
| collection | Thesis |
| dc_rights_str_mv | © 2012 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MEng)--University of Pretoria, 2012. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/25840 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:36:42.914Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/25840 Geometric optimization for the maximum heat transfer density rate from cylinders rotating in natural convection Bello-Ochende, Tunde page.lg@gmail.com Meyer, Josua P. Page, L.G. (Logan Garrick) Rotating cylinders Optimal packing Mathematical optimization Natural convection Multi scale Counter-rotation Heat transfer density rate UCTD Dissertation (MEng)--University of Pretoria, 2012. In this study we investigates the thermal behavior of an assembly of consecutive cylinders in a counter-rotating configuration cooled by natural convection with the objective of maximizing the heat transfer density rate (heat transfer rate per unit volume). A numerical model was used to solve the governing equations that describe the temperature and flow fields and an optimization algorithm was used to find the optimal structure for flow configurations with two or more degrees of freedom. The geometric structure of the consecutive cylinders was optimized for each flow regime (Rayleigh number) and cylinder rotation speed for one and two degrees of freedom. Smaller cylinders were placed at the entrance to the assembly, in the wedge-shaped flow regions occupied by fluid that had not yet been used for heat transfer, to create additional length scales to the flow configuration. It was found that the optimized spacing decreases and the heat transfer density rate increases as the Rayleigh number increases, for the optimized structure. It was also found that the optimized spacing decreases and the maximum heat transfer density rate increases, as the cylinder rotation speed was increased for the single scale configuration at each Rayleigh number. Results further showed that there was an increase in the heat transfer density rate of the rotating cylinders over stationary cylinders for a single scale configuration. For a multi scale configuration it was found that there was almost no effect of cylinder rotation on the maximum heat transfer density rate, when compared to stationary cylinders, at each Rayleigh number; with the exception of high cylinder rotation speeds, which serve to suppress the heat transfer density rate. It was, however, found that the optimized spacing decreases as the cylinder rotation speed was increased at each Rayleigh number. Results further showed that the maximum heat transfer density rate for a multi scale configuration (with stationary cylinders) was higher than a single scale configuration (with rotating cylinders) with an exception at very low Rayleigh numbers. Mechanical and Aeronautical Engineering unrestricted 2013-09-07T00:52:04Z 2012-10-01 2013-09-07T00:52:04Z 2012-09-06 2012-10-01 2012-06-25 Dissertation Page, LG 2012, Geometric optimization for the maximum heat transfer density rate from cylinders rotating in natural convection, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/25840 > C12/9/13/ag http://hdl.handle.net/2263/25840 http://upetd.up.ac.za/thesis/available/etd-06252012-144413/ © 2012 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | Rotating cylinders Optimal packing Mathematical optimization Natural convection Multi scale Counter-rotation Heat transfer density rate UCTD Geometric optimization for the maximum heat transfer density rate from cylinders rotating in natural convection |
| title | Geometric optimization for the maximum heat transfer density rate from cylinders rotating in natural convection |
| title_full | Geometric optimization for the maximum heat transfer density rate from cylinders rotating in natural convection |
| title_fullStr | Geometric optimization for the maximum heat transfer density rate from cylinders rotating in natural convection |
| title_full_unstemmed | Geometric optimization for the maximum heat transfer density rate from cylinders rotating in natural convection |
| title_short | Geometric optimization for the maximum heat transfer density rate from cylinders rotating in natural convection |
| title_sort | geometric optimization for the maximum heat transfer density rate from cylinders rotating in natural convection |
| topic | Rotating cylinders Optimal packing Mathematical optimization Natural convection Multi scale Counter-rotation Heat transfer density rate UCTD |
| url | http://hdl.handle.net/2263/25840 http://upetd.up.ac.za/thesis/available/etd-06252012-144413/ |