ABSTRACT
In
the
current
work,
study
examines
flow
patterns
and
heat
transfer
capabilities
of
tubes
with
various
spherical
dimple
configurations.
A
numerical
analysis,
supported
by
experimental
validation
on
a
reference
model,
was
conducted
circular
tube
an
alternating
path.
The
primary
goal
to
enhance
thermal
performance
inducing
mixing
vortex
flows.
impact
three
design
factors
thermal–hydraulic
investigated,
pipe
diameter
(DPD),
group
number
(DGN),
dimples
(NODs).
Dimpled
consistently
outperformed
smooth
in
due
increased
separation.
Both
increasing
Reynolds
decreasing
led
formation
patterns.
evaluation
factor
(PEF)
varied
across
different
For
DPD,
PEF
ranged
from
1.14
1.33;
for
DGN,
it
1.15
1.28;
NOD,
0.95
1.21,
all
within
range
4000–15,000.
At
6000,
configurations
NOD
terms
Nusselt
number.
improvements
25.7%
30.8%,
friction
21%
67%.
DGN
exhibited
wider
enhancement
25%
49.6%,
increase
37%
72%.
also
demonstrated
consistent
improvements,
increases
ranging
27.35%
31%
42%
74%.
Spherical
can
significantly
tubes,
so
best
configuration
depends
specific
application,
highest
performance,
1.33
PEF,
achieved
2
mm
(DPD
=
mm)
density
four
per
unit
area
(NOD
4).
Case Studies in Thermal Engineering,
Год журнала:
2024,
Номер
61, С. 104899 - 104899
Опубликована: Авг. 2, 2024
The
article
presents
a
comprehensive
simulation
study
on
cold
storage
porous
containers,
employing
the
Galerkin
method
to
analyze
their
thermal
behavior.
A
key
focus
of
investigation
is
incorporation
both
radiation
and
conduction
modes
within
mathematical
model,
acknowledging
significant
roles
in
freezing
process.
To
enhance
rate,
hybrid
nanoparticles
are
introduced
into
H2O,
aiming
speed
up
solidification.
Notably,
integrates
adaptive
grid
techniques
achieve
higher
modeling
accuracy,
with
verification
processes
confirming
high
level
agreement
between
results
experimental
data.
This
research
also
underscores
potential
for
improved
energy
efficiency
systems,
contributing
sustainability
natural
resources
by
reducing
consumption
enhancing
overall
systems.
Through
meticulous
examination,
explores
impacts
various
factors
freezing,
including
fraction
nano-powders
(ϕ),
porosity
(γ),
factor
(Rd).
Remarkably,
introduction
media
causes
substantial
increment
resulting
an
improvement
approximately
91.19
%.
Moreover,
inclusion
term
model
significantly
reduces
completion
time
30.85
%,
underscoring
importance
considering
effects
such
Additionally,
dispersing
water,
decrement
around
7.21
approach
highlights
optimizing
use
applications,
thereby
promoting
conservation
sustainable
management
resources.
Case Studies in Thermal Engineering,
Год журнала:
2024,
Номер
60, С. 104779 - 104779
Опубликована: Июль 1, 2024
This
article
thoroughly
examined
the
impact
of
Lorentz
and
buoyancy
forces
on
movement
nanomaterials
within
a
sealed
container.
The
magnetic
field
was
aligned
with
x-axis,
while
gravity
acted
along
y-axis.
container
featured
heated
inner
surface
curved
outer
kept
at
lower
temperature,
permeable
domain
allowing
fluid
flow.
Using
various
shapes
found
to
enhance
heat
transfer
effectively.
investigation
provides
valuable
insights
into
optimizing
in
practical
applications
by
utilizing
interaction
between
forces.
analysis
applied
Darcy's
formulation
account
for
media
simplified
equations
using
stream
function
concept.
numerical
code
underwent
rigorous
verification
ensure
its
accuracy
reliability.
Introducing
nanoparticles
significantly
increased
Nusselt
number
(Nu),
indicating
an
approximate
41.42
%
improvement
efficiency.
Additionally,
raising
parameter
"m"
resulted
11.76
increase
Nu.
However,
increasing
Ha
led
46.72
reduce
Nu,
reflecting
reduced
In
contrast,
boosting
Rayleigh
(Ra)
substantially
enhancing
efficiency
about
59.78
%.
Case Studies in Thermal Engineering,
Год журнала:
2024,
Номер
57, С. 104296 - 104296
Опубликована: Март 23, 2024
This
study
conducts
a
simulation
of
the
freezing
through
container
featuring
finned
sinusoidal
geometry.
The
application
Galerkin
method
effectively
captures
intricate
dynamics
unsteady
processes,
showcasing
significant
enhancement
by
introducing
nanoparticles
to
augment
system's
thermal
conductivity—an
essential
element
for
optimizing
conduction
efficiency.
numerical
approach
underscores
importance
employing
an
adaptive
grid
in
scenarios,
tailoring
based
on
solid
front's
position
due
heightened
scalar
gradients.
Various
powder
diameters
(dp)
and
fractions
(ϕ)
are
systematically
investigated,
elucidating
their
distinct
impacts
process
duration.
Results
reveal
that
initial
increase
dp
causes
decrement
period
19.93%,
followed
subsequent
rise
49.06%,
specifically
scenarios
with
0.04
nanoparticle
concentration.
incorporation
yields
noteworthy
41.13%
decrease
solidification
time
when
optimal
sizes
utilized.
In
contrast,
without
additives
is
278.95s,
reduced
164.19s
introduction
optimally
sized
powders.
Case Studies in Thermal Engineering,
Год журнала:
2024,
Номер
56, С. 104232 - 104232
Опубликована: Март 11, 2024
A
novel
machine-learning
model
for
micro
and
mini-channel
friction
factor
prediction
is
presented
in
this
article.
In
recent
years,
periodic
array
offset
strip
fins
mini
channels
have
gained
attention
due
to
their
compactness
aid
heat
transfer
chemical
processing
electronic
cooling
devices.
The
research
uses
fin
length-to-height
ratios
below
one,
Reynolds
numbers
between
one
six
hundred
contain
2765
geometrically
dimensioned.
factor,
the
most
significant
barrier
channel
use,
must
be
accurately
estimated
design
efficient
systems.
Krylov
subspace
method
implemented
using
finite
element
FEniCS
software.
Additionally,
three
machine
learning
algorithms,
Catboost,
XGboost,
Random
Forest
regressors,
are
predict
steady
flow
through
with
arrays,
corresponding
performance
analysed.
stacking
ensemble
proposed
enhance
precision
of
forecasts.
results
demonstrate
that
outperforms
empirical
correlations
predicting
values
specific
evaluation
metrics
an
absolute
error
0.403%,
indicating
represents
complexity
data.
