Articles, Conference and Workshop Papers Collection
http://www.suaire.sua.ac.tz/handle/123456789/83
Mon, 29 May 2023 11:53:46 GMT2023-05-29T11:53:46ZEffects of navier slip and wall permeability on entropy generation in unsteady generalized couette flow of nanofluids with convective cooling
http://www.suaire.sua.ac.tz/handle/123456789/5102
Effects of navier slip and wall permeability on entropy generation in unsteady generalized couette flow of nanofluids with convective cooling
Mwizu, Michael H; Makinde, Oluwole D.; Nkansah-Gyekye, Yaw
Present work investigates the effects of generalized Couette flow with
convective cooling, Navier slip and permeable walls on entropy generation in an
unsteady of water based nanofluids containing Copper (Cu) and Alumina (Al 2 O 3 ) as
nanoparticles. Both first and second laws of thermodynamics are applied to analyse
the problem. The nonlinear governing equations of momentum and energy are
solved numerically using a semi discretization finite difference method together with
Runge-Kutta Fehlberg integration scheme. Graphical results on the effects of
different parameter variations on velocity, temperature, skin friction, Nusselt
number, entropy generation rate, and Bejan number are presented and discussed.
Article
Thu, 01 Jan 2015 00:00:00 GMThttp://www.suaire.sua.ac.tz/handle/123456789/51022015-01-01T00:00:00ZOn Vladimirov’s approximation for ideal in homogeneous MHD
http://www.suaire.sua.ac.tz/handle/123456789/5094
On Vladimirov’s approximation for ideal in homogeneous MHD
Callebaut, D. K.; Karugila, G. K.; Khater, A. H.
Vladimirov and Vladimirov and Moffat have considered configurations in ideal magnetohydrodynamics, i.e.
inviscid and perfectly conducting. The matter is considered as incompressible. However, the density is allowed
to vary slowly. They base the following approximation on this slow variation: they omit the mass density in
front of the total derivative of the velocity in the equation of motion. Normally the mass density should appear
in front of Du. This is a tremendous simplification which allows them to obtain various interesting results
concerning the stability of the configurations. However, in such a kind of approximation the results might be
only crude. However, in many applications the results are OK, because crucial in those papers is the vanishing
of ∇ρ × ∇φ. Often both gradients are parallel and the results obtained by Vladimirovs approximation are
nevertheless valid, e.g. in the application to inhomogeneous gas clouds and protostars. Moreover for small
density gradients and/or nearly parallel gradients the approximation is fair. We even suggest an approximation
which may be more correct and avoids the term ∇ρ × ∇φ. Hence for linear perturbations and stability analyses
the results may turn out to be acceptable. However, for nonlinear stability a more extended analysis is required.
Journal article
Mon, 01 Aug 2005 00:00:00 GMThttp://www.suaire.sua.ac.tz/handle/123456789/50942005-08-01T00:00:00ZEffect of E × B drifts in convective zone
http://www.suaire.sua.ac.tz/handle/123456789/5066
Effect of E × B drifts in convective zone
Callebaut, Dirk K.; Karugila, Geoffrey K.; Makarov, Valentin I.
The E × B drift allows plasma to move through the magnetic field lines and may
contribute to various motions inside the Sun (e.g. to explain the adverse gradient of differential rotation in the equatorial zone), at its surface and in the corona. Here we treat an example: using a given azimuthal angular frequency ω(r, θ), rather arbitrary, and the corresponding exact solution for B, we obtain E and the drift velocity. The latter is comparable with the original velocity, but has components in all directions
Journal article
Thu, 01 Jan 2004 00:00:00 GMThttp://www.suaire.sua.ac.tz/handle/123456789/50662004-01-01T00:00:00ZInvestigation of effect of rock storage system parameters on thermal cooling performance
http://www.suaire.sua.ac.tz/handle/123456789/5058
Investigation of effect of rock storage system parameters on thermal cooling performance
Matofali, Alex Xavery; Massawe, Estomih S.
We investigate the effects of key parameters of the rock bed system on thermal cooling performance of the system
after a fixed time of operation. The method of solving the mathematical model uses a semi-discretization finite difference
approximation for discretizing space in solid problem domain. A finite element approximation is used in the fluid problem
domain. Graphical results on the effects of parameter variation on damping and time delay on the peaking of the outlet air
temperature through the bed are presented and discussed.
Journal article
Fri, 15 Jan 2016 00:00:00 GMThttp://www.suaire.sua.ac.tz/handle/123456789/50582016-01-15T00:00:00Z