الفهرس 
LITERATURE SURVEYOnly 14 pages are availabe for public view
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Abstract
Vortex breakdown In swirling flows IS characterized by an abrupt
change in the structure of the nominally axisymmetric core. The main
objective of the present thesis is to give the results of theoretical
investigations of axisymmetric vortex breakdown, therefore, been solved
partial differential equations, which describe the phenomenon.
For this purpose, the finite difference scheme is proposed and
investigated theoretically as well as numerically by solving the equations
describing the axisymmetric vortex breakdown which called Navier-Stokes
equations.
Steady solutions of the Navier-Stokes equations, in terms of velocity
and pressure, for breakdown are obtained numerically using the ”Artificial
Compressibility” technique combined with an ”Alternating Direction
Implicit” finite-difference scheme. Axisymmetry is assumed and boundary
conditions are carefully applied at the boundaries of a large finite region in an
axial plane while resolution near the axis is maintained by a coordinate
transformation.
Comparing the theoretical results, which are obtained for the same
Reynolds numbers based on the free-stream axial velocity and a characteristic
core radius, with [Hafez et al 1986] show that a slight difference of 4% and
this should be considered within the descent agreement in the comparisons of
theory.
Significantly, on one hand, this work shows that the axial velocity near
the axis (w axis) decreases with axial length (z) and then back again to
increase. Also, it is found that with increasing the value of specified circumferential velocity (V) increasing in the rate of decrease In aXIS
velocity is happened near the axis as a result of the phenomenon.
On the other hand, the swirl velocity (tz) decreases with increasing in
(2). Moreover, it’s noticed that the rate of decrease is small at the small
circumferential velocity (V).
The results agreed with the practical results of others have been
offering some curves to clarify this.