Physics of Fluids,
Journal Year:
2024,
Volume and Issue:
36(10)
Published: Oct. 1, 2024
Micro
vortex
generators
(mVGs)
control
cavitation
by
altering
the
boundary
layer
flow
structure.
This
study
employs
wall-adapting
local
eddy-viscosity
large
eddy
simulation
(WALE-LES)
turbulence
model
combined
with
Zwart–Gerber–Belamri
to
conduct
transient
numerical
simulations
on
National
Advisory
Committee
for
Aeronautics
0015
baseline
hydrofoil
and
equipped
mVGs
under
various
numbers.
The
proper
orthogonal
decomposition
method
experiments
verify
accuracy
consistency
of
these
regarding
cavity
scale.
elucidates
mechanisms
which
suppress
cloud
at
low
numbers
induce
high
Results
indicate
that
maintain
sheet
characteristics
numbers,
reducing
wall
pressure
fluctuations
enhancing
stability.
During
inception,
mVG-induced
leads
early
formation.
In
phase,
modal
energy
distribution
is
more
dispersed,
while
in
inception
concentrated
significant
dominant
modes.
Moreover,
counter-rotating
vortices
generated
mitigate
separation,
enhance
leading-edge
attachment
stability,
reduce
high-frequency
vibrations
caused
bubble
shedding.
significantly
advances
understanding
accurately
simulating
revealing
across
different
stages
using
WALE-LES
model.
findings
demonstrate
can
effectively
stabilize
structures
instabilities
overall
performance.
These
insights
will
have
a
impact
design
hydrofoils
development
strategies.
Physics of Fluids,
Journal Year:
2023,
Volume and Issue:
35(12)
Published: Dec. 1, 2023
In
this
paper,
the
noise
characteristics
of
tip
leakage
vortex
cavitation
(TLVC)
inception
are
numerically
investigated
using
a
previously
developed
hybrid
Eulerian–Lagrangian
model
[Wang
et
al.,
“Numerical
investigation
how
gap
size
influences
method,”
Phys.
Fluids
35,
012113
(2023).]
and
porous
Ffowcs-Williams
Hawkings
analogy
method.
A
significantly
affects
far-field
noise,
which
is
louder
for
large
gaps
than
small
gaps,
high-frequency
band
low-
medium-frequency
bands.
Wavelet
theoretical
analyses
show
that
main
broadband
source
multiple
collapses
cavitating
bubbles
intensity
positively
related
to
maximum
bubble
radius.
The
radius
depends
on
unsteady
pressure
evolution
at
TLV
center,
where
mean
mainly
influenced
by
velocity
fluctuation
results
from
boundary
layer
roll-up.
This
paper
reveals
hydroacoustic
mechanism
TLVC
inception,
can
provide
insight
into
reduction
techniques.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(2)
Published: Feb. 1, 2025
This
study
develops
a
hybrid
multiscale
Euler–Lagrange
model
to
investigate
the
unsteady
characteristics
of
cloud
cavitation
around
hydrofoil
under
different
water
qualities.
A
homogeneous
mixture
is
implemented
for
macroscopic
cavity
simulations,
tracking
vapor–liquid
interfaces.
In
Lagrangian
framework,
dynamics
and
motion
nuclei
bubbles
are
resolved.
By
incorporating
more
physically
accurate
conversion
criteria
couple
two
frameworks,
modified
ensure
consistency
with
assumption
that
inception
arises
from
expansion
nuclei.
Numerical
results,
obtained
size
distributions
populations,
align
well
experimental
data,
validating
capability
account
effects
quality.
They
also
offer
detailed
insights
into
influence
flows
on
microscale
bubble
behavior,
particularly
highlighting
significant
role
reentry
jets
in
generation
motion.
The
results
underscore
critical
interplay
between
small-scale
flows.
addition,
statistical
analysis
distribution
microbubbles
reveals
law
consistent
observations.
provides
robust
framework
investigating
comprehensive
quality
flows,
offering
promising
avenue
future
research
this
domain.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(2)
Published: Feb. 1, 2025
The
present
study
employs
a
two-way
coupled
multi-scale
method
to
simulate
and
analyze
the
cloud
cavitation
flow
around
hydrofoil,
based
on
which
distribution
of
erosion
risk
hydrofoil
is
evaluated.
numerical
results
demonstrate
that
can
capture
not
only
overall
evolution
characteristics
but
also
generation,
growth,
collapse
small-scale
bubbles.
Throughout
majority
cycle,
scale
Lagrange
bubbles
roughly
follows
logarithmic
Gaussian
distribution.
However,
it
shows
double-peak
characteristic
as
result
bubble
production
from
both
sheet
cavity
shedding
cloud.
local
risk,
closely
aligned
with
experimental
findings,
assessed
greatest
near
closure
line
cavity,
due
breakdown
vapor
structures
during
development
reentrant
jet.
During
highest
when
forms
decreases
moves
downstream.
analysis
reveals
number
alone
insufficient
for
characterizing
its
erosive
effects.
For
given
number,
mean
diameter
increases
inflow
velocity.
Furthermore,
total
impact
energy
power-law
dependence
Scientific Reports,
Journal Year:
2025,
Volume and Issue:
15(1)
Published: Feb. 5, 2025
Cavitation
is
a
technical
challenge
for
high-speed
underwater
vehicles,
such
as
nuclear
submarines
and
robots,
et
al.
The
cavitation
phenomena
of
hydrofoils
are
typically
studied
through
water
tunnel
experiments
or
numerical
simulations,
which
yield
extensive
images.
To
conveniently
extract
features
from
the
massive
images,
feature
extraction
method
hydrofoil
was
proposed
in
this
work
based
on
deep
learning
image
semantic
segmentation
techniques.
This
employed
to
investigate
mechanism
transition
process
sheet
cloud
hydrofoils.
accuracy
generalization
ability
have
been
validated.
results
indicate
that,
addition
accurately
obtaining
length
automatically,
can
also
derive
more
sensitive
indicators
area
position
changes
regions.
heightened
sensitivity
invaluable
precisely
pinpointing
sheet-like
cavitation,
thereby
aiding
effective
analysis
development
attached
cavitation.
In
summary,
our
not
only
streamlines
images
but
enhances
understanding
mechanisms
by
providing
additional
data
analysis.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(2)
Published: Feb. 1, 2025
Freestream
nuclei,
also
referred
to
as
water
quality,
are
known
significantly
affect
cavitation
inception.
However,
their
effects
on
fully
developed
and
the
corresponding
noise
characteristics
remain
inadequately
understood.
In
this
study,
a
multiscale
hydroacoustic
model
based
Euler–Lagrangian
framework
is
used
investigate
impact
of
quality
monopole
sheet
tip-leakage
vortex
(TLV)
cavitating
flow.
Cavitating
flows
over
National
Advisory
Committee
for
Aeronautics
0009
hydrofoil
under
varying
qualities
simulated,
results
compared
with
those
from
conventional
Eulerian
experimental
observations.
The
findings
indicate
that
sound
pressure
radiated
by
exhibits
same
baseline
signature
across
different
qualities,
but
more
intense
peaks
observed
in
nuclei-depleted
For
TLV
cavitation,
higher
acoustic
predicted
“weak”
water,
while
lower
extreme
loud
events
“strong”
consistent
cavity
evolution
shows
strong
pulses
generated
result
collapse
rebound
cavity.
Additionally,
smaller
arises
absence
tip-separation
intermittency
stronger
pulse
originates
complete
cavity,
phenomenon
not
weak
water.
both
types,
frequency-domain
analysis
reveals
amplified
high-frequency
range
degassed,
likely
linked
dynamic
behavior
local
cavities.
