Spelling suggestions: "subject:"[een] NEWTONIAN"" "subject:"[enn] NEWTONIAN""
11 |
High Reynolds number flow in a collapsible channelGuneratne, Julie Clare January 1999 (has links)
No description available.
|
12 |
Numerical spectral solution of elliptic partial differential equations using domain decomposition techniquesMalek, Alaeddin January 1991 (has links)
No description available.
|
13 |
The quantum politics metaphor in international relations : revising American NewtonianismAkrivoulis, Dimitrios Efthymiou January 2002 (has links)
No description available.
|
14 |
Lie group analysis of equations arising in non-Newtonian fluidsMamboundou, Hermane Mambili 08 April 2009 (has links)
It is known now that the Navier-Stokes equations cannot describe the behaviour of fluids having
high molecular weights. Due to the variety of such fluids it is very difficult to suggest
a single constitutive equation which can describe the properties of all non-Newtonian fluids.
Therefore many models of non-Newtonian fluids have been proposed.
The flow of non-Newtonian fluids offer special challenges to the engineers, modellers, mathematicians,
numerical simulists, computer scientists and physicists alike. In general the equations
of non-Newtonian fluids are of higher order and much more complicated than the Newtonian
fluids. The adherence boundary conditions are insufficient and one requires additional
conditions for a unique solution. Also the flow characteristics of non-Newtonian fluids are
quite different from those of the Newtonian fluids. Therefore, in practical applications, one
cannot replace the behaviour of non-Newtonian fluids with Newtonian fluids and it is necessary
to examine the flow behaviour of non-Newtonian fluids in order to obtain a thorough
understanding and improve the utilization in various manufactures.
Although the non-Newtonian behaviour of many fluids has been recognized for a long time,
the science of rheology is, in many respects, still in its infancy, and new phenomena are
constantly being discovered and new theories proposed. Analysis of fluid flow operations
is typically performed by examining local conservation relations, conservation of mass, momentum
and energy. This analysis gives rise to highly non-linear relationships given in terms
of differential equations, which are solved using special non-linear techniques.
Advancements in computational techniques are making easier the derivation of solutions to
linear problems. However, it is still difficult to solve non-linear problems analytically. Engineers,
chemists, physicists, and mathematicians are actively developing non-linear analytical
techniques, and one such method which is known for systematically searching for exact solutions
of differential equations is the Lie symmetry approach for differential equations.
Lie theory of differential equations originated in the 1870s and was introduced by the Norwegian
mathematician Marius Sophus Lie (1842 - 1899). However it was the Russian scientist
Ovsyannikov by his work of 1958 who awakened interest in modern group analysis. Today,
the Lie group approach to differential equations is widely applied in various fields of
mathematics, mechanics, and theoretical physics and many results published in these area
demonstrates that Lie’s theory is an efficient tool for solving intricate problems formulated in
terms of differential equations.
The conditional symmetry approach or what is called the non-classical symmetry approach
is an extension of the Lie approach. It was proposed by Bluman and Cole 1969. Many equations
arising in applications have a paucity of Lie symmetries but have conditional symmetries.
Thus this method is powerful in obtaining exact solutions of such equations. Numerical
methods for the solutions of non-linear differential equations are important and nowadays
there several software packages to obtain such solutions. Some of the common ones are included
in Maple, Mathematica and Matlab.
This thesis is divided into six chapters and an introduction and conclusion. The first chapter
deals with basic concepts of fluids dynamics and an introduction to symmetry approaches to
differential equations. In Chapter 2 we investigate the influence of a time-dependentmagnetic
field on the flow of an incompressible third grade fluid bounded by a rigid plate. Chapter 3
describes the modelling of a fourth grade flow caused by a rigid plate moving in its own
plane. The resulting fifth order partial differential equation is reduced using symmetries and
conditional symmetries. In Chapter 4 we present a Lie group analysis of the third oder PDE
obtained by investigating the unsteady flow of third grade fluid using the modified Darcy’s
law. Chapter 5 looks at the magnetohydrodynamic (MHD) flow of a Sisko fluid over a moving
plate. The flow of a fourth grade fluid in a porous medium is analyzed in Chapter 6. The
flow is induced by a moving plate. Several graphs are included in the ensuing discussions.
Chapters 2 to 6 have been published or submitted for publication. Details are given in the
references at the end of the thesis.
|
15 |
Investigation of Stokes' second problem for non-Newtonian fluidsRikhotso, Deals Shaun 12 June 2014 (has links)
The motion of an incompressible fluid caused by the oscillation of a plane at plate of in nite length is termed Stokes' second problem. We assume zero velocity normal to the plate and thus simpli ed Navier-Stokes equations.
For the unsteady Stokes' second problem, solutions may be obtained by
using Laplace transforms, perturbation techniques, homotopy, di erential
transform method or Adomian decomposition method. Stokes' second problem
is discussed for second-grade and Oldroyd-B non-Newtonian fluids. This dissertation summarizes previously published work.
|
16 |
An experimental study of combined forced and free convective heat transfer to non-Newtonian fluids in the thermal entry region of a horizontal pipeKim, Yong Jin, 1956- 27 April 1990 (has links)
Graduation date: 1990
|
17 |
A theoretical analysis of non-Newtonian flow in wire-coating diesAstfalk, Gregory, 1948- January 1976 (has links)
No description available.
|
18 |
Phenomonological behaviour of particles in Newtonian and non-Newtonian liquids.Bartram, Eric. January 1973 (has links)
No description available.
|
19 |
Swimming in slimePachmann, Sydney 11 1900 (has links)
The purpose of this thesis is to study the problem of a low Reynolds number
swimmer that is in very close proximity to a wall or solid boundary in a non-
Newtonian fluid. We assume that it moves by propagating waves down its length
in one direction, creating a thrust and therefore propelling it in the opposite
direction. We model the swimmer as an infinite, inextensible waving sheet.
We consider two main cases of this swimming sheet problem. In the first
case, the type of wave being propagated down the length of the swimmer is
specified. We compare the swimming speeds of viscoelastic shear thinning,
shear thickening and Newtonian fluids for a fixed propagating wave speed. We
then compare the swimming speeds of these same fluids for a fixed rate of work
per wavelength. In the latter situation, we find that a shear thinning fluid
always yields the fastest swimming speed regardless of the amplitude of the
propagating waves. We conclude that a shear thinning fluid is optimal for the
swimmer. Analytical results are obtained for various limiting cases. Next, we
consider the problem with a Bingham fluid. Yield surfaces and flow profiles are
obtained.
In the second case, the forcing along the length of the swimmer is specified,
but the shape of the swimmer is unknown. First, we solve this problem for a
Newtonian fluid. Large amplitude forcing yields a swimmer shape that has a
plateau region following by a large spike region. It is found that there exists
an optimal forcing that will yield a maximum swimming speed. Next, we solve
the problem for moderate forcing amplitudes for viscoelastic shear thickening
and shear thinning fluids. For a given forcing, it is found that a shear thinning
fluid yields the fastest swimming speed when compared to a shear thickening
fluid and a Newtonian fluid. The difference in swimming speeds decreases as
the bending stiffness of the swimmer increases.
|
20 |
Rheological characterization of high density polyethylene with processing aids in capillary flow and its implications in a non-isothermal annular flow processNguyen, Khanh Phuong 08 1900 (has links)
No description available.
|
Page generated in 0.0415 seconds