Experimental and numerical investigation into the natural convection of TiO2-water nanofluid

This Master of Engineering investigation focuses on the natural convection of nanofluids in rectangular cavities. The governing equations applied to analyse the heat transfer and fluid flow occurring within the cavity are given and discussed. Special attention is given to the models that were develo...

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Main Author: Ottermann, Tanja Linda
Other Authors: Sharifpur, Mohsen
Language:en
Published: University of Pretoria 2017
Subjects:
Online Access:http://hdl.handle.net/2263/61323
Ottermann, TL 2016, Experimental and numerical investigation into the natural convection of TiO2-water nanofluid, MEng Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/61323>
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spelling ndltd-netd.ac.za-oai-union.ndltd.org-up-oai-repository.up.ac.za-2263-613232020-06-02T03:18:37Z Experimental and numerical investigation into the natural convection of TiO2-water nanofluid Ottermann, Tanja Linda Sharifpur, Mohsen u11011255@tuks.co.za Meyer, Josua P. UCTD Nanofluid Natural convection Titanium dioxide Volume fraction This Master of Engineering investigation focuses on the natural convection of nanofluids in rectangular cavities. The governing equations applied to analyse the heat transfer and fluid flow occurring within the cavity are given and discussed. Special attention is given to the models that were developed to predict the thermal conductivity and dynamic viscosity of such nanofluids. A review concerning past investigations into the field of natural convection of nanofluids in cavities is made. The investigation is divided into experimental works and computational fluid dynamics (CFD) numerical investigations. Through the literature review, it was discovered that many numerical models exist for the prediction of the thermophysical properties of nanofluids, specifically thermal conductivity and viscosity. Depending on the nanofluid and the application, different models can be used. The literature study also revealed that most previous works were done in the CFD field. Very few experimental studies have been performed. Numerical CFD investigations, however, need experimental results for validation purposes, leading to the conclusion that more experimental work is needed. The heat transfer capability and thermophysical properties of the nanofluid are investigated based on models found in literature. The investigation incudes measuring the heat transfer inside a cavity filled with a nanofluid and subjected to a temperature gradient. The experiment is performed for several volume fractions of particles. An optimum volume fraction of 0.005 is obtained. At this volume fraction the heat transfer enhancement reaches a maximum for the present investigation. The investigation is repeated as a numerical investigation using the commercially available CFD software ANSYS-FLUENT. The same case as used in the experimental investigation is modelled as a two-dimensional case and the results are compared. The same optimum volume fraction and maximum heat transfer is obtained with an insignificantly small difference between the two methods of investigation. This error can be attributed to the minor heat losses experienced from the experimental setup as in the CFD adiabatic walls considered. It is concluded that, through the inclusion of TiO2 particles in the base fluid (deionised water), the thermophysical properties and the heat transfer capability of the fluid are altered. For a volume fraction of 0.005 and heat transfer at a temperature difference of 50 °C, the heat transferred through the fluid in the cavity is increased by more than 8%. From the results, it is recommended that the investigation is repeated with TiO2 particles of a different size to determine the dependency of the heat transfer increase on the particle size. Various materials should also be tested to determine the effect that material type has on the heat transfer increase. Dissertation (MEng)--University of Pretoria, 2016. Mechanical and Aeronautical Engineering MEng Unrestricted 2017-07-13T13:28:56Z 2017-07-13T13:28:56Z 2017-04-26 2016 Dissertation http://hdl.handle.net/2263/61323 Ottermann, TL 2016, Experimental and numerical investigation into the natural convection of TiO2-water nanofluid, MEng Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/61323> A2017 11011255 en © 2017 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. University of Pretoria
collection NDLTD
language en
sources NDLTD
topic UCTD
Nanofluid
Natural convection
Titanium dioxide
Volume fraction
spellingShingle UCTD
Nanofluid
Natural convection
Titanium dioxide
Volume fraction
Ottermann, Tanja Linda
Experimental and numerical investigation into the natural convection of TiO2-water nanofluid
description This Master of Engineering investigation focuses on the natural convection of nanofluids in rectangular cavities. The governing equations applied to analyse the heat transfer and fluid flow occurring within the cavity are given and discussed. Special attention is given to the models that were developed to predict the thermal conductivity and dynamic viscosity of such nanofluids. A review concerning past investigations into the field of natural convection of nanofluids in cavities is made. The investigation is divided into experimental works and computational fluid dynamics (CFD) numerical investigations. Through the literature review, it was discovered that many numerical models exist for the prediction of the thermophysical properties of nanofluids, specifically thermal conductivity and viscosity. Depending on the nanofluid and the application, different models can be used. The literature study also revealed that most previous works were done in the CFD field. Very few experimental studies have been performed. Numerical CFD investigations, however, need experimental results for validation purposes, leading to the conclusion that more experimental work is needed. The heat transfer capability and thermophysical properties of the nanofluid are investigated based on models found in literature. The investigation incudes measuring the heat transfer inside a cavity filled with a nanofluid and subjected to a temperature gradient. The experiment is performed for several volume fractions of particles. An optimum volume fraction of 0.005 is obtained. At this volume fraction the heat transfer enhancement reaches a maximum for the present investigation. The investigation is repeated as a numerical investigation using the commercially available CFD software ANSYS-FLUENT. The same case as used in the experimental investigation is modelled as a two-dimensional case and the results are compared. The same optimum volume fraction and maximum heat transfer is obtained with an insignificantly small difference between the two methods of investigation. This error can be attributed to the minor heat losses experienced from the experimental setup as in the CFD adiabatic walls considered. It is concluded that, through the inclusion of TiO2 particles in the base fluid (deionised water), the thermophysical properties and the heat transfer capability of the fluid are altered. For a volume fraction of 0.005 and heat transfer at a temperature difference of 50 °C, the heat transferred through the fluid in the cavity is increased by more than 8%. From the results, it is recommended that the investigation is repeated with TiO2 particles of a different size to determine the dependency of the heat transfer increase on the particle size. Various materials should also be tested to determine the effect that material type has on the heat transfer increase. === Dissertation (MEng)--University of Pretoria, 2016. === Mechanical and Aeronautical Engineering === MEng === Unrestricted
author2 Sharifpur, Mohsen
author_facet Sharifpur, Mohsen
Ottermann, Tanja Linda
author Ottermann, Tanja Linda
author_sort Ottermann, Tanja Linda
title Experimental and numerical investigation into the natural convection of TiO2-water nanofluid
title_short Experimental and numerical investigation into the natural convection of TiO2-water nanofluid
title_full Experimental and numerical investigation into the natural convection of TiO2-water nanofluid
title_fullStr Experimental and numerical investigation into the natural convection of TiO2-water nanofluid
title_full_unstemmed Experimental and numerical investigation into the natural convection of TiO2-water nanofluid
title_sort experimental and numerical investigation into the natural convection of tio2-water nanofluid
publisher University of Pretoria
publishDate 2017
url http://hdl.handle.net/2263/61323
Ottermann, TL 2016, Experimental and numerical investigation into the natural convection of TiO2-water nanofluid, MEng Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/61323>
work_keys_str_mv AT ottermanntanjalinda experimentalandnumericalinvestigationintothenaturalconvectionoftio2waternanofluid
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