الفهرس 
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Abstract
Ice formation phenomena and heat transfer around isothermally
cooled cylinders, which are lined in a cross flow .of cold water,
were experimentally and theoretically studied.
An experimental test rig was designed and constructed for this
study. Also, numerical analysis technique using Fluent software,
was used to determine the local heat transfer coefficient on the
surface of the ice.
During the experimental work, the free-stream water velocity
was changed from 0.03 to 0.08 mls and dimensionless cooling
temperature ratio (8 ) was varing from 4.6 to 7.7.
In the numerical analysis of the ice formation phenomena
Fluent program was used. Three parameters were studied, freestream
water velocity, dimensionless cooling temperature and
cylinder pitch. Free-stream water velocity was changed from 0.030.08
rn/s, cylinder pitch is varying from 60 mm, 80 mm, 100 mm
and 120mm and dimensionless cooling temperature ratio (8 ) is
varying from 3.3, 6.6, 10 and 13.3.
Three pattern of ice layer shapes around the cylinders were
observed:
a- Linked Ice layer shape, where all the cylinders are
completely linked with an ice-layer. For certain values of cylinder ~.
ABSTRACT
Ice formation phenomena and heat transfer around isothermally
cooled cylinders, which are lined in a cross flow .of cold water,
were experimentally and theoretically studied.
An experimental test rig was designed and constructed for this
study. Also, numerical analysis technique using Fluent software,
was used to determine the local heat transfer coefficient on the
surface of the ice.
During the experimental work, the free-stream water velocity
was changed from 0.03 to 0.08 mls and dimensionless cooling
temperature ratio (8 ) was varing from 4.6 to 7.7.
In the numerical analysis of the ice formation phenomena
Fluent program was used. Three parameters were studied, freestream
water velocity, dimensionless cooling temperature and
cylinder pitch. Free-stream water velocity was changed from 0.030.08
rn/s, cylinder pitch is varying from 60 mm, 80 mm, 100 mm
and 120mm and dimensionless cooling temperature ratio (8 ) is
varying from 3.3, 6.6, 10 and 13.3.
Three pattern of ice layer shapes around the cylinders were
observed:
a- Linked Ice layer shape, where all the cylinders are
completely linked with an ice-layer. For certain values of cylinder
IV
pitch and dimensionless cooling temperature, the .linked ice layer
occures at low values of Reynolds number. Mean while at a
certain values of cylinder pitch and Reynolds number linked
ice layer occurs at higher values of dimensionless cooling
temperature.
b- Transition Ice layer shape, where the ice layer is not
linked between some of the cylinders at the beginning of cylinder
row, while the. other cylinders are completely linked with ice layer.
c- Disconnected ice layer shape, where the ice is formed
individually around each cylinder. This usual occurs at higher
values of free stream water velocity i.e. higher values of Reynolds
number.
For the experimental and theoretical work, under the conditions
of linked ice layer, a general correlation between the local Nusselt
number, Nux, and the local Reynolds number (Rex, Red),
dimensionless cooling temperature ratio (9) and dimensionless
cylinder pitch (p*) expressed as follows:
Nux = 0.00045 Rexo.96Redo.69-0.sp* 0.7
The difference between the values of the correlation equations
from experimental and theoretical results and the general
correlation equation had been calculated. It was found that the
difference within ± 40 %.