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).
ABSTRACT
Corrugated
pipe
is
used
in
many
engineering
applications
because
of
its
high
performance
compared
with
smooth
pipe.
This
research
involved
numerical
simulations
and
experimental
testing
a
circular
tube
modified
flow
path
to
improve
the
heat
transfer
exchangers.
The
focus
was
on
enhancing
mixing
creating
vortex
flows
within
increase
exchange
efficiency.
impact
seven
design
factors,
including
ring
diameters
(RD)
pitch
between
pitches
(RP),
thermal–hydraulic
investigated.
Water
as
working
fluid
regime
ranges
from
4000
15,000,
indicating
turbulent
flow.
A
constant
flux
25,500
W/m
2
applied,
water
enters
system
at
temperature
298
K
(25°C).
properties
are
assumed
remain
throughout
conditions,
such
steady
state
(the
conditions
do
not
change
time),
incompressible
density
remains
constant),
no‐slip
condition
velocity
surface
any
solid
boundary
zero).
tubes
consistently
outperformed
due
increased
separation.
Both
increasing
Reynolds
number
decreasing
factors
led
formation
patterns.
In
RD
configurations,
Nusselt
saw
an
average
improvement
approximately
45.6%,
while
friction
factor
19%
57%.
RP
configurations
demonstrated
broader
range
enhancements,
reaching
up
35%,
increases
ranging
15%
42%.
Rings
can
significantly
enhance
tubes.
However,
best
configuration
depends
specific
application.
highest
performance,
resulting
1.38
evaluation
factor,
obtained
using
1
mm
20
mm.
simulated
data
showed
excellent
agreement,
maximum
discrepancy
less
than
11%
for
both
dimpled
Case Studies in Thermal Engineering,
Год журнала:
2024,
Номер
57, С. 104287 - 104287
Опубликована: Март 24, 2024
To
maximize
the
efficiency
of
freezing,
combinations
using
nanoparticles
and
fins
have
been
utilized
in
current
work.
Incorporating
nanofluids
into
solidification
processes
provides
a
refined
efficient
approach
to
transitioning
materials
from
liquid
solid
state.
Triangular
container
involving
has
implemented.
The
shape
fraction
were
varied
this
research.
derived
equations
solved
via
finite
element
method
associated
code
validated
based
on
prior
article.
reduction
freezing
time
was
presumed
as
main
goal
research
resource
utilization
various
industries.
As
greater
amount
nano-powders
is
utilized,
conduction
becomes
stronger
rate
improves
about
27%.
Also,
altering
particles
applying
powders
with
bigger
m
can
lead
by
7%.
Case Studies in Thermal Engineering,
Год журнала:
2024,
Номер
55, С. 104165 - 104165
Опубликована: Фев. 22, 2024
The
present
study
investigates
the
enhancement
of
PVT
system
efficiency
through
application
magnetic
force.
Dust
deposition
affects
glass
layer
PV,
altering
magnitude
heat
sources.
addition
a
thermoelectric
layer,
attached
to
silicon
using
EVA,
allows
for
increased
electrical
output.
A
rhombus-shaped
duct
is
filled
with
homogeneous
mixture
H2O
and
Fe3O4
nanomaterial
serving
as
ferrofluid.
dust
over
results
in
decline
useful
by
approximately
10.11%,
leading
25.36%
productivity.
imposition
MHD
increases
thermal
performance
8.9%,
can
be
enhanced
1.8%.
dispersion
nanoparticles
contributes
cooler
this
positive
impact
being
three
times
greater
absence
MHD.
Additionally,
an
increase
inlet
velocity
8.22%
improvement
performance.
Heat Transfer,
Год журнала:
2024,
Номер
54(1), С. 420 - 459
Опубликована: Сен. 13, 2024
Abstract
Enhanced
pipe
surfaces
offer
greater
heat
transfer
enhancement
due
to
increased
turbulence
levels,
leading
improved
exchange
performance.
This
study
combines
numerical
simulations
and
experimental
work
identify
the
best
geometric
design
of
enhanced
tubes
for
thermal–hydraulic
performance,
flow
structure,
pressure
drop,
are
validated
with
data.
Water
is
a
working
fluid
Reynolds
numbers
ranging
from
4000
15,000,
q
=
25,500
W/m
2
,
an
inlet
temperature
298
K
constant
property,
steady
state,
no‐slip
condition.
The
three‐dimensional
incompressible
turbulent
in
concavity
dimpled
shape‐enhanced
numerically
studied.
research
found
that
pipes
concave
shape
most
effectively.
overall
significantly
influenced
by
dimples,
their
arrangement
rings,
size
these
number
rings.
However,
cylindrical
dimples
does
not
seem
impact
much.
increase
performance
was
9.8%–61%
dimple
rings
2ring
performed
compared
smooth
8.21%–38.49%
at
effect
ring
as
grouping,
also
diameters
5%–38%
7%–39%
numbers.
evaluation
factor
(PEF)
assesses
considering
both
drop
penalty
transfer.
optimal
configuration
achieving
highest
(PEF
1.295)
rate
(
Re
)
involves
single
2‐mm
diameter,
spaced
10‐mm
apart,
containing
four
dimples.
Furthermore,
discussing
different
parameters
thermal
hydraulic
performances
obtain
increasing
gives
better
guide
engineering
thermohydraulic
exchangers.
Journal of Thermal Analysis and Calorimetry,
Год журнала:
2024,
Номер
149(11), С. 5595 - 5609
Опубликована: Май 27, 2024
Abstract
In
pursuit
of
advancing
the
efficiency
cold
energy
storage,
a
uniquely
designed
curved
container
has
been
employed,
filled
with
water-nanoparticle
mixtureQ.
The
is
equipped
fins,
strategically
leveraging
enhanced
conduction
facilitated
by
presence
nanoparticles.
simulation
intricate
unsteady
phenomena
in
this
study
conducted
using
finite
element
technique,
providing
robust
analytical
framework.
incorporation
an
adaptive
grid
ensures
refined
resolution,
particularly
vicinity
ice
front
region.
nanoparticle
fraction
(
ϕ
)
emerges
as
pivotal
factor
directly
influencing
rate
solidifying.
dispersion
nano-powders
leads
to
noteworthy
reduction
completion
time,
demonstrating
substantial
33.21%
improvement.
diameter
(dp)
introduces
diverse
effects
on
solidification
process,
primarily
due
its
significant
influence
conductivity
nanomaterial.
An
in-depth
exploration
impact
dp
reveals
compelling
insights.
As
increases
from
smallest
size
40
nm,
there
commendable
15.12%
required
freezing
time.
However,
subsequent
increment
beyond
threshold
results
notable
36.56%
increase
findings
presented
here
not
only
contribute
fundamental
understanding
processes
but
also
hold
practical
implications
for
design
and
optimization
storage
systems.
Numerical Heat Transfer Part B Fundamentals,
Год журнала:
2024,
Номер
unknown, С. 1 - 16
Опубликована: Май 6, 2024
The
thermal
analysis
of
two-phase
models
that
deal
with
the
fluid
and
dusty
phases
has
been
considered.
This
study
instigates
flow
a
non-miscible,
hybrid
nanofluid
over
stretching
cylinder
Darcy–Forchheimer
permeability
in
presence
radiation.
mathematical
model
is
based
on
single-phase
model,
which
features
modified
thermophysical
characteristics.
innovative
explores
how
important
it
to
enhance
concentration
dust
particles
dynamics.
Hybrid
nanoparticles
are
substituted
for
conventional
case
accelerate
heat
transfer
rate
fluid.
Therefore,
this
study,
magnetohydrodynamic
nanofluids
non-Newtonian
fluids
suspensions
have
examined.
appropriate
dimensionless
variables
used
convert
governing
periodic
into
non-dimensional
form.
finite-difference-based
bvp5c
algorithm
through
Matlab
numerical
set
obtained
ordinary
differential
equations.
graphs
explored
influences
relatable
factors
profiles
mass,
heat,
velocity
transfers.
It
observed
intensifying
values
Eckert
number
(Ec)
Biot
(Bi),
temperature
both
increased
at
significant
level,
decreased
increasing
intensity
magnetic
field.
computational
results
velocity,
core
temperature,
dispersion
aspects.
Furthermore,
exhibit
declining
behavior
as
result
impact
porosity,
mass
concentration,
magnetism
stream.
Moreover,
noticed
phase
θp(η)
θ(η)
intensified
high
field
missile
nozzles,
nuclear
power
plants
aerospace
gaseous-core
rocket
systems,
radiation
considered
evaluating
heating
significance.
