Computational analysis of non-isothermal flow of non-Newtonian fluids

The dynamics of complex fluids under various conditions is a model problem in bio-fluidics and in process industries. We investigate a class of such fluids and flows under conditions of heat and/or mass transfer. Experiments have shown that under certain flow conditions, some complex fluids (e.g. wo...

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Main Author: Ireka, Ikenna Ebubechukwu
Other Authors: Chinyoka, Tirivanhu
Format: Doctoral Thesis
Language:English
Published: University of Cape Town 2015
Subjects:
Online Access:http://hdl.handle.net/11427/15590
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spelling ndltd-netd.ac.za-oai-union.ndltd.org-uct-oai-localhost-11427-155902020-07-22T05:07:46Z Computational analysis of non-isothermal flow of non-Newtonian fluids Ireka, Ikenna Ebubechukwu Chinyoka, Tirivanhu Mathematics and Applied Mathematics The dynamics of complex fluids under various conditions is a model problem in bio-fluidics and in process industries. We investigate a class of such fluids and flows under conditions of heat and/or mass transfer. Experiments have shown that under certain flow conditions, some complex fluids (e.g. worm-like micellar solutions and some polymeric fluids) exhibit flow instabilities such as the emergence of regions of different shear rates (shear bands) within the flow field. It has also been observed that the reacting mixture in reaction injection molding of polymeric foams undergoes self-expansion with evolution of heat due to exothermic chemical reaction. These experimental observations form the foundation of this thesis. We explore the heat and mass transfer effects in various relevant flow problems of complex fluids. In each case, we construct adequate mathematical models capable of describing the experimentally observed flow phenomena. The mathematical models are inherently intractable to analytical treatment, being nonlinear coupled systems of time dependent partial differential equations. We therefore develop computational solutions for the model problems. Depending on geometrical or mathematical complexity, finite difference or finite volume methods will be adopted. We present the results from our numerical simulations via graphical illustrations and validate them (qualitatively) against' similar' results in the literature; the quotes being necessary in keeping in mind the novelties introduced in our investigations which are otherwise absent in the existing literature. In the case where experimental data is available, we validate our numerical simulations against such experimental results. 2015-12-04T18:04:57Z 2015-12-04T18:04:57Z 2015 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/15590 eng application/pdf University of Cape Town Faculty of Science Department of Mathematics and Applied Mathematics
collection NDLTD
language English
format Doctoral Thesis
sources NDLTD
topic Mathematics and Applied Mathematics
spellingShingle Mathematics and Applied Mathematics
Ireka, Ikenna Ebubechukwu
Computational analysis of non-isothermal flow of non-Newtonian fluids
description The dynamics of complex fluids under various conditions is a model problem in bio-fluidics and in process industries. We investigate a class of such fluids and flows under conditions of heat and/or mass transfer. Experiments have shown that under certain flow conditions, some complex fluids (e.g. worm-like micellar solutions and some polymeric fluids) exhibit flow instabilities such as the emergence of regions of different shear rates (shear bands) within the flow field. It has also been observed that the reacting mixture in reaction injection molding of polymeric foams undergoes self-expansion with evolution of heat due to exothermic chemical reaction. These experimental observations form the foundation of this thesis. We explore the heat and mass transfer effects in various relevant flow problems of complex fluids. In each case, we construct adequate mathematical models capable of describing the experimentally observed flow phenomena. The mathematical models are inherently intractable to analytical treatment, being nonlinear coupled systems of time dependent partial differential equations. We therefore develop computational solutions for the model problems. Depending on geometrical or mathematical complexity, finite difference or finite volume methods will be adopted. We present the results from our numerical simulations via graphical illustrations and validate them (qualitatively) against' similar' results in the literature; the quotes being necessary in keeping in mind the novelties introduced in our investigations which are otherwise absent in the existing literature. In the case where experimental data is available, we validate our numerical simulations against such experimental results.
author2 Chinyoka, Tirivanhu
author_facet Chinyoka, Tirivanhu
Ireka, Ikenna Ebubechukwu
author Ireka, Ikenna Ebubechukwu
author_sort Ireka, Ikenna Ebubechukwu
title Computational analysis of non-isothermal flow of non-Newtonian fluids
title_short Computational analysis of non-isothermal flow of non-Newtonian fluids
title_full Computational analysis of non-isothermal flow of non-Newtonian fluids
title_fullStr Computational analysis of non-isothermal flow of non-Newtonian fluids
title_full_unstemmed Computational analysis of non-isothermal flow of non-Newtonian fluids
title_sort computational analysis of non-isothermal flow of non-newtonian fluids
publisher University of Cape Town
publishDate 2015
url http://hdl.handle.net/11427/15590
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