Thesis (DTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2013 / The flow of reactive viscous fluids in porous media presents a theoretically challenging problem
and has a broad range of scientific, technological and engineering applications. Real life areas
where such flow systems are encountered include drying of food, geothermal energy extraction,
nuclear waste disposal, the flow of heat and fluid inside human organs, insulation of buildings,
groundwater movement, oil and gas production, astrophysical plasmas, magnetohydrodynamic
(MHD) pumps and generators, metal extraction and granulation of metals, aerospace and ship
propulsion and automobile exhaust systems. The reactions within such flow systems are
inherently exothermic. It is in this view that we carry out studies of thermal effects and thermal
stability criteria for unsteady flows of reactive variable viscosity non-Newtonian fluids through
saturated porous media. The study focuses on non-Newtonian fluids mainly because the
majority of industrial fluids exhibit non-Newtonian character. Particular focus will be on fluids of
the differential type exemplified by third grade fluid.
Both analytical and numerical techniques were employed to solve the nonlinear partial
differential equations that were derived from the conservation principles, namely the principles
of conservation of mass, momentum and energy balance. Graphical representations were
adopted in trying to explain the response of solutions to various flow parameter variations.
In chapter 1 we defined important terms and expressions, laid down a summary of important
applications, carried out literature survey, stated the statement of the problem, the aims and
objectives of the study as well as an outline of the envisaged research methodology. Chapter 2
focuses on the derivations of the fundamental equations that derive the flow system. These are
the continuity equation, the momentum equation and the energy equation.
In chapter 3 we computationally investigated the unsteady flow of a reactive temperature
dependent viscosity third grade fluid through a porous saturated medium with asymmetric
convective boundary conditions. The response of velocity and temperature fields to each of the
various flow parameters was analysed and interpreted. A transient increase in both the velocity
and temperature profiles with an increase in the reaction strength, viscous heating and fluid
viscosity parameter was observed. On the other hand, a transient decrease in the field
properties was observed with increase in non-Newtonian character and the porous medium
shape parameter. The reaction was noticed to blow-up if, depending on other flow parameters,
the reaction strength is not carefully controlled.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:cput/oai:localhost:20.500.11838/1306 |
| Date | January 2013 |
| Creators | Rundora, Lazarus |
| Publisher | Cape Peninsula University of Technology |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | http://creativecommons.org/licenses/by-nc-sa/3.0/za/ |
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