Journal of Engineering and Applied Science,
Год журнала:
2024,
Номер
71(1)
Опубликована: Дек. 1, 2024
Abstract
Nanofluids
in
microchannels
present
a
promising
solution
for
enhancing
heat
dissipation
across
various
engineering
applications.
This
study
provide
an
in-depth
analysis
of
nanofluid
role
improving
transfer
efficiency,
focusing
on
critical
factors
such
as
nanoparticle
concentration,
type,
and
size.
The
influence
microchannel
geometry—such
sinusoidal,
square,
circular
designs—and
the
addition
rib
structures
were
also
examined.
A
noticeable
increase
pressure
drop
was
observed
spectrum
investigations
beyond
concentration
threshold
1
vol.
%.
Diverging-converging
channels
demonstrated
potential
with
minimal
pumping
power.
Most
reviewed
papers
have
used
water
water-ethylene
glycol
mixtures
(65%
16%,
respectively),
along
prevalent
use
Al
2
O
3
nanoparticles
(37%),
underscoring
need
to
explore
alternative
base
fluids
combinations
achieve
optimal
performance.
focus
numerical
simulations
61%
75%
single-phase
flow
studies
highlights
expand
research
into
multiphase
phenomena.
Furthermore,
limited
exploration
shape
effects
reliance
simplistic
thermal
conductivity
models
point
toward
avenues
future
investigation
model
refinement.
Energies,
Год журнала:
2023,
Номер
16(23), С. 7885 - 7885
Опубликована: Дек. 2, 2023
Despite
numerous
studies
on
nanofluids
in
microchannel
heat
sinks
(MCHSs),
they
are
not
yet
commercialized
due
to
long-term
stability
issues
and
high
maintenance
costs.
Therefore,
this
study
explores
the
impact
of
nanoparticle
clustering
single-phase
convective
transfer
inside
microchannels
under
laminar
conditions.
Water
commercially
available
water-based
nanosuspensions,
including
Al2O3-water
(30–60
nm),
TiO2-water
(5–30
polystyrene-water
(50
circulated
through
silicon
MCHS
having
rectangular
channels
integrated
into
a
closed
flow
loop.
To
assess
situ
real-time
during
experiments,
Light
Extinction
Spectroscopy
(LES)
is
applied
as
non-intrusive
measurement
technique
without
any
fluid
sampling.
Our
findings
reveal
appearance
nanofluid
discoloration
with
no
measurable
increase
coefficient.
This
unexpected
change
attributed
interplay
abrasion,
erosion,
corrosion
phenomena,
likely
triggered
by
nanoparticles
within
microchannels—a
novel
insight
complex
dynamics
behavior
(an
De
Brouckere
mean
diameter
from
11
nm
107.3
over
2.5
h
period
for
TiO2
nanoparticles).
The
resulting
material
loss
could
be
mitigated
altering
material,
which
may
impede
enhancement
tested
Journal of Thermal Analysis and Calorimetry,
Год журнала:
2024,
Номер
149(12), С. 6433 - 6457
Опубликована: Май 30, 2024
Abstract
This
numerical
research
study
focuses
on
impacts
of
using
twisted
rib
geometry
the
hydrothermal
performance
and
entropy
generation
characteristics
biologically
synthesized
Ag/water
nanofluid
flowing
in
heat
sink
minichannels.
To
this
end,
twelve
different
geometries
(Case
1
to
12)
were
designed
where
double-row
ribs
at
bottom
top
portions
with
twist
angles
between
−
45°
+
45°.
elucidate
cooling
comprehensively,
four
Reynolds
numbers
(Re
=
500,
1000,
1500,
2000)
nanoparticle
concentrations
(
$$
\varphi
\hspace{0.17em}$$
φ
0%,
0.1%,
0.5%,
1%)
included
computations.
Results
revealed
that
significantly
smoothen
fluid
flow
reduces
pressure
drop
remarkably
depending
angles,
nevertheless,
it
deteriorates
performance.
In
Case
12,
convective
transfer
coefficient
by
up
15.8%
Re
2000
\varphi$$
=1%,
compared
base
case.
However,
pumping
power
requirement
is
decreased
43.9%
Nanoparticle
incorporation
contributes
enhancement
13.5%
lowest
Re.
Frictional
considerably
decreases
(up
31%)
when
are
utilized.
thermal
can
increase
36%,
due
ineffective
ribs.
work
be
regarded
as
a
first
field
concerning
effects
nanofluid-cooled
mini-channel
sinks.
Energies,
Год журнала:
2024,
Номер
17(21), С. 5486 - 5486
Опубликована: Ноя. 1, 2024
In
this
paper,
the
performance
of
aluminum-based
nanofluids
with
a
possible
application
in
pressurized
water
reactors
is
numerically
investigated.
A
605
mm
long
4-rod
array
square
(2
×
2)
subchannel
geometry
uniform
heat
flux
50
kW/m2
has
been
used
CFD
simulation.
This
analysis
carried
out
using
RNG
k-epsilon
turbulence
model
standard
wall
function
ANSYS
FLUENT
2022R1.
The
impact
various
flow
conditions
and
nanofluid
concentrations
examined.
effects
variable
velocities
on
have
studied
different
Reynolds
numbers
20,000,
40,000,
60,000,
80,000.
was
conducted
Al2O3/water
1%,
2%,
3%,
4%.
comparison
Nusselt
number
based
five
correlations
conducted,
deviations
from
each
correlation
were
then
presented.
homogeneous
single-phase
mixer
approach
adopted
to
characteristics.
result
shows
gradual
enhancement
transfer
coefficient
increasing
volume
numbers.
maximum
calculated
for
at
(ϕ
=
4%)
highest
(Re
80,000).
Compared
base
fluid,
enhanced
by
factor
1.09
4%
Al2O3.
minimal
error
3.62%
when
compared
Presser
deviation
found
Dittus–Boelter
(13.77%).
Overall,
findings
suggest
that
could
offer
capabilities
reactors.
Case Studies in Thermal Engineering,
Год журнала:
2024,
Номер
58, С. 104429 - 104429
Опубликована: Апрель 26, 2024
The
continuous
development
of
innovative
cooling
techniques
is
imperative
for
advancing
electronic
device
performance,
enhancing
efficiency,
and
prolonging
their
operational
reliability
in
an
ever-evolving
technological
landscape.
In
this
numerical
investigation,
the
hydrothermal
performance
entropy
generation
aspects
a
heat
sink
featuring
Tesla
valve-base
helical
channels
are
explored
using
two-phase
mixture
method.
chosen
transfer
fluid
water-silver
nanofluid
synthesized
through
biological
study
delved
into
impact
Reynolds
number
(
=500-2000)
concentration
=0-1%)
on
system's
functional
parameters,
results
subsequently
compared
with
data
associated
employing
plain
channels.
It
was
uncovered
that
elevating
diminishing
result
improved
central
processing
unit
(CPU)
cooling,
lowered
thermal
resistance,
reduction
temperature
differential
between
maximum
minimum
CPU
temperatures.
Meanwhile,
pumping
power
increases
higher
s
lower
s.
Furthermore,
it
discovered
overall
valve-type
channel
consistently
surpasses
channel.
peak
value
Performance
Evaluation
Criterion,
reaching
1.642,
Case
=500
&
=0%.
found
substituting
decrease
total
up
to
1500.
