Physics of Fluids,
Journal Year:
2023,
Volume and Issue:
35(3)
Published: Feb. 25, 2023
Proper
orthogonal
decomposition
(POD)
enables
complex
flow
fields
to
be
decomposed
into
linear
modes
according
their
energy,
allowing
the
key
features
of
extracted.
However,
traditional
POD
requires
high-quality
inputs,
namely,
high-resolution
spatiotemporal
data.
To
alleviate
dependence
on
quality
and
quantity
data,
this
paper
presents
a
method
that
is
strengthened
by
physics-informed
neural
network
(PINN)
with
an
overlapping
domain
strategy.
The
loss
function
convergence
are
considered
simultaneously
determine
PINN-POD
model.
proposed
framework
applied
past
two-dimensional
circular
cylinder
at
Reynolds
numbers
ranging
from
100
10
000
achieves
accurate
robust
extraction
structures
spatially
sparse
observation
spatial
dominant
frequency
can
also
extracted
under
high-level
noise.
These
results
demonstrate
reliable
tool
for
extracting
data
fields,
potentially
shedding
light
data-driven
discovery
hidden
fluid
dynamics.
Physics of Fluids,
Journal Year:
2023,
Volume and Issue:
35(3)
Published: Feb. 16, 2023
In
this
research,
the
cavitating
flow
around
a
NACA0015
(National
Advisory
Committee
for
Aeronautics)
hydrofoil
obtained
by
large-eddy
simulation
method
is
analyzed
using
proper
orthogonal
decomposition
(POD)
theory.
Various
fundamental
mechanisms
have
been
investigated
thoroughly,
including
reentrant
jet
behavior,
pressure
gradient
mechanism,
vortex
dynamics,
and
dynamic
properties
of
hydrofoil.
The
influence
temporal/spatial
evolution
revealed.
POD
indicates
that
first
four
dominant
modes
occupy
97.4%
entire
energy.
Based
on
force
field
extracted
from
single
modes,
it
found
lift-and-drag
characteristics
in
are
determined
specific
spatial
distribution
mode
structures.
addition,
coupling
velocity
pulsations
fluctuations
carried
out
to
obtain
modal
field,
which
reveals
has
close
connection
with
cavity
evolution.
Furthermore,
reconstructed
17
160
low-order
without
impact
small-scale
structures
noise
can
clearly
capture
aspects
field.
Journal of Fluids Engineering,
Journal Year:
2024,
Volume and Issue:
146(6)
Published: Feb. 22, 2024
Abstract
To
simulate
the
microscale
bubble
distribution
and
its
effect
on
high-frequency
cavitation
noise,
we
present
a
two-way
transition
coupling
Euler–Lagrange
model.
The
model
accounts
for
both
cavity
fission
environmental
nucleation
as
sources
of
bubbles,
which
are
limited
in
traditional
mesh-based
Euler
models.
We
evaluate
with
experimental
data
truncated
NACA0009
hydrofoil
well
measured
size
distributions,
showing
satisfactory
results
velocity
distribution,
patterns,
power
law
scalings
size.
Based
an
acoustic
analogy,
find
that
produces
sound
waves
smaller
wavelengths
higher
frequencies
than
model,
mainly
attributed
to
two
factors:
(1)
bubbles
high
natural
frequency
(2)
intense
multiple
collapse/rebound
behavior.
This
is
promising
predicting
full-spectrum
noise.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(1)
Published: Jan. 1, 2025
This
study
employs
the
two-dimensional
proper
orthogonal
decomposition
approach
to
analyze
pressure,
vapor
fraction,
and
streamwise
velocity
flowfields
of
partial
cavity
oscillation.
The
interrelations
among
mode,
energy
ratio,
temporal
coefficient,
flowfield
reconstruction
are
thoroughly
examined,
thereby
augmenting
comprehension
cavitating
flow
mechanism
bubble
dynamics.
It
is
found
that
first
modes
contain
56.31%,
36.37%,
31.81%
energy,
respectively;
decrease
in
ratio
results
variation
its
coefficient
close
sinusoidal
configurations.
Moreover,
mode
varies
closely
related
flowfield-relevant
variable.
significantly
different,
but
all
have
two
highlighted
structures
self-variable
system.
strong
nonlinearity
high
dimensionality
cavitation
render
precise
using
a
limited
number
exceedingly
challenging.
data
approximate
original
snapshot
more
when
field
reconstructed
with
greater
modes.
Although
location
relatively
root
mean
square
error
different
nine
used
for
reconstruction,
order
magnitude
less
than
system,
discrepancy
fixed,
equal
1.
