Aerospace,
Journal Year:
2024,
Volume and Issue:
11(12), P. 1032 - 1032
Published: Dec. 17, 2024
Non-equilibrium
condensation
involves
intricate
physics,
making
it
crucial
to
thoroughly
investigate
the
factors
that
influence
it.
Understanding
these
is
essential
for
optimizing
system
performance
and
minimizing
negative
effects
associated
with
non-equilibrium
condensation.
This
study
focused
on
examining
impact
of
various
operational
conditions
in
a
saturated
mode
within
supersonic
nozzle.
The
operation
under
investigation
involved
pressures
25
kPa,
50
75
100
kPa.
Each
saturation
state
was
examined
assess
its
effect
parameters,
such
as
temperature,
pressure,
liquid
mass
fraction,
droplet
radius,
nucleation
rate,
Mach
number,
count.
A
consistent
pattern
emerged
across
all
samples.
As
gas
accelerated
through
converging
section
nozzle,
both
pressure
temperature
gradually
decreased.
However,
upon
reaching
throat
entering
divergent
section,
phenomenon
known
shock
occurred.
wave
caused
sudden
significant
spike
temperature.
Following
shock,
parameters
resumed
their
downward
trend
along
remaining
length
Interestingly,
increasing
initial
led
less
intense
shock.
Additionally,
raising
at
nozzle
inlet
resulted
larger
droplets
higher
concentration
flow.
By
quadrupling
from
substantial
106.9%
increase
radius
9.65%
fraction
were
observed
outlet.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(2)
Published: Feb. 1, 2025
To
enhance
industrial
equipment,
it
is
crucial
to
have
a
thorough
understanding
of
the
occurring
phenomena
within
it.
Nonequilibrium
condensation
one
such
phenomenon
that
requires
comprehensive
investigation
and
study,
as
commonly
observed
in
equipment.
The
present
study
investigates
homogeneous
(HMC),
homogeneous–heterogeneous
(HMTC),
heterogeneous
(HTC)
through
implementation
liquid
droplet
injection
technique.
Two
contrasting
modeling
approaches
are
employed
for
analysis
HMTC.
In
Model
A,
discrete
simulation
performed
nucleating
injected
droplets,
with
each
group
modeled
independently.
B,
simplified
approach
employed,
where
radii
droplets
averaged
represent
combined
population.
results
demonstrate
HMC,
HMTC,
HTC
significantly
influence
flow
structure.
vapor
molecules
converging
nozzle
section
HMTC
elevated
pressure,
mass
fraction
(LMF),
temperature,
alongside
decrease
Mach
number
supersaturation
ratio.
scenario,
A
exhibits
higher
values
shock
intensity,
nucleation
rate,
number,
LMF,
two-phase
heat
compared
B.
When
comparing
outlet
average
LMF
difference
approximately
8%
Sample
1
6%
2.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(3)
Published: March 1, 2025
Non-equilibrium
condensation
(NQC)
is
a
critical
process
within
supersonic
nozzle,
leading
to
thermodynamic
losses
and
significant
alterations
in
the
flow
structure.
The
release
of
latent
heat
during
NQC
results
increased
pressure,
temperature,
reduction
Mach
number.
This
study
investigates
influence
different
input
vapor
types—superheated,
saturated,
supercooled—on
structure
two-phase
regimes
nozzle.
A
compressible
model
employed
simulate
behavior.
Results
reveal
that
type
has
profound
impact
on
pattern.
Supercooled
associated
with
gradual
pressure
increase
converging
section,
whereas
saturated
superheated
vapors
exhibit
abrupt
surges
at
throat
diverging
section.
Furthermore,
supercooled
demonstrates
higher
mass
fraction
liquid
larger
droplet
radii
compared
vapors.
Saturated
exhibits
highest
rate,
while
experiences
loss.
Superheated
vapor,
other
hand,
entropy
production.
Compared
10-degree
1.33%
decrease
9.06%
loss,
reductions
frictional
thermal
production
by
3.61%
2.56%,
respectively.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(2)
Published: Feb. 1, 2025
The
development
of
energy-efficient
and
clean
supercritical
water
gasification
product
(SCWGP)
separation
technology
has
become
one
the
bottlenecks
in
advancing
technology.
This
study
suggests
utilizing
a
supersonic
nozzle
to
condense
separate
H2
CO2
from
SCWGP.
flow
condensation
model
are
established
for
bicubic
parametric
nozzle,
effects
various
operating
conditions
on
SCWGP
analyzed.
liquid
phase
mass
fraction
at
outlet
is
significantly
influenced
by
inlet
pressure
temperature.
approximate
relationship
between
variations
0.065
per
MPa,
while
temperature
approximately
–0.013
K.
latent
heat
released
during
process
significant
impact
distribution
within
nozzle.
Inlet
parameters
have
notable
effect
peak
values
positions
nucleation
droplet
growth
rates.
condensed
primarily
concentrated
near
center
outlet.
efficiency
strongly
molar
gas
mixture,
small
amount
N2
mixed
little
performance.
Chemical Product and Process Modeling,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 18, 2025
Abstract
Non-equilibrium
condensation
(NEC)
is
a
prevalent
phenomenon
in
various
industrial
equipment,
and
it
can
substantially
affect
their
operational
efficiency
overall
performance.
Droplet
nucleation
growth
one
of
the
important
aspects
NEC
needs
to
be
investigated
studied,
whatever
affects
these
parameters.
On
other
hand,
has
considerable
impact
on
flow
pattern
shock
causes
sudden
change
This
study
been
conducted
with
aim
investigating
inlet
pressure
(IP)
two-phase
The
values
90
kPa,
95
99.98
105
110
kPa
are
considered
as
nozzle
IP
for
this
investigation,
its
parameters
pressure,
temperature,
speed,
density,
droplet
radius,
liquid
mass
fraction
(LMF),
rate,
Number
drops
condensed
rate.
According
results,
increases,
occurs
earlier
LMF
increases.
As
increases
from
amount
by
about
5.7
%,
more
produced
nozzle.
provides
good
understanding
NEC.
Chemical Product and Process Modeling,
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 8, 2025
Abstract
The
escalating
global
concern
over
climate
change
and
the
urgent
need
for
sustainable
solutions
have
propelled
renewable
energy
technologies
into
spotlight.
Among
these,
refrigeration
cycles
emerged
as
a
promising
research
area,
offering
environmentally
friendly
alternatives
to
traditional
systems.
Ejector
(ERCs),
particularly
those
employing
water
working
fluid,
garnered
significant
attention
due
their
inherent
advantages.
To
further
optimize
performance
of
ERCs,
comprehensive
understanding
underlying
flow
phenomena
impact
on
system
efficiency
is
crucial.
primary
objective
explore
secondary
superheating
ejector’s
characteristics.
A
parametric
study
conducted
by
varying
degree
from
0
K
30
while
maintaining
constant
pressures
1,200
Pa
1,800
Pa.
results
revealed
that
overall
pattern
remained
relatively
unaffected
increase
in
superheating,
exergy
destruction
were
significantly
impacted.
noteworthy
observation
inverse
relationship
between
entrainment
ratio.
As
increases,
ratio
exhibits
corresponding
decrease.
For
instance,
30-degree
superheat
resulted
2.8
%
3.9
reduction
at
Pa,
respectively.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(3)
Published: March 1, 2025
In
various
engineering
applications,
the
phase
change
from
steam
to
water
droplet
during
rapid
expansion
under
supersonic
flow
conditions
is
inevitable.
The
occurrence
of
condensation
waves
due
latent
heat
released
and
aerodynamic
shocks
reduces
equipment
performance.
Given
complexities
two-phase
flow,
researchers
have
always
been
interested
in
developing
an
accurate
numerical
method
that
can
be
used
different
regimes
while
reducing
computation
costs.
This
research
has
developed
a
two-dimensional
code
using
simple
low-dissipation
advection
upstream
splitting
(SLAU)
high-resolution
(HR-SLAU)
complex
geometry
turbine
blades
convergent–divergent
nozzles.
performance
these
two
schemes
was
examined
Eulerian–Lagrangian
model
boundary
conditions.
governing
equations
are
investigated
Eulerian
model,
which
incorporates
SLAU
HR-SLAU
schemes,
for
determining
wet
parameters
solved
by
Lagrangian
approach
predict
liquid
mass
grid
cell.
Comparative
experimental
data,
regarding
simplicity
absence
any
tuning
flow-dependent
variable,
determination
position
intensity
improved
considerably,
radius
prediction
significantly
enhanced.
Notably,
scheme,
dissipation
component
pressure
flux
according
cell-interface
orientation
angle
characteristics
locally
controlled
coefficient
modeling
flows,
leads
fewer
errors.
