Physics of Fluids,
Journal Year:
2023,
Volume and Issue:
35(11)
Published: Nov. 1, 2023
Vortex-Induced
Vibration
(VIV)
of
multiple
cylinders
has
received
increasing
attention
in
the
ocean
engineering
field
recent
years.
In
this
paper,
a
two-dimensional
numerical
model
for
studying
VIV
is
developed.
Based
on
fixed
Cartesian
grid
with
local
mesh
refinement
adopted,
immersed
boundary
method
utilized
to
account
existence
cylinders.
Two-degree-of-freedom
single
circular
cylinder
simulated
validate
model,
and
then
four
circular-cylinder
group
square
arrangement.
The
mass
ratio
m*
=
2.0,
spacing
L/D
5.0,
where
L
central
displacement
two
adjacent
D
diameter
Reynolds
number
ranging
from
45
210
considered,
variation
which
achieved
by
changing
inflow
velocity.
corresponding
reduced
velocity
varies
3
14.
influences
vibrating
frequencies,
response
amplitudes,
X–Y
trajectories,
vorticity
distribution,
hydrodynamic
coefficients
are
analyzed
detail.
A
critical
105
observed,
at
trajectories
distribution
change
their
patterns.
Ocean Engineering,
Journal Year:
2022,
Volume and Issue:
261, P. 111611 - 111611
Published: Aug. 13, 2022
The
application
of
unsteady
incompressible
flow
phenomenon
over
the
bluff
bodies
has
received
attention
many
researchers
due
to
rich
and
complex
physics
underpinning
these
flows,
thus
requiring
special
in
their
modelling
numerical
simulations.
wake
that
forms
at
leeside
body
is
particular
interest.
Reynolds
number
geometry
are
turn
two
prominent
parameters
govern
formation
subsequent
behaviour
this
wake.
This
paper
reviews
formations
for
different
cylindrical
cross-sections
such
as
circular,
elliptical,
helically
twisted
symmetric
wavy,
asymmetric
harbor
seal
vibrissae
cylinders.
Alongside
geometrical
shape,
impacts
rotational
rate,
aspect
ratio,
angle
attack,
gap
ratio
between
cylinder
bottom
wall
on
hydrodynamic
coefficients,
Strouhal
number,
recirculation
length
suppression
vortex
shedding
investigated.
In
addition,
variation
coefficients
shapes
compared.
Finally,
concluding
remarks
drawn
based
recent
advances
understanding
features
predictions
with
CFD
methods.
Physics of Fluids,
Journal Year:
2022,
Volume and Issue:
34(5)
Published: May 1, 2022
A
novel
data-driven
nonlinear
reduced-order
modeling
framework
is
proposed
for
unsteady
fluid–structure
interactions
(FSIs).
In
the
framework,
a
convolutional
variational
autoencoder
model
developed
to
determine
coordinate
transformation
from
high-dimensional
physical
field
into
reduced
space.
This
enables
efficient
extraction
of
low-dimensional
manifolds
flow
FSIs.
The
sparse
identification
dynamics
(SINDy)
algorithm
then
used
identify
dynamical
governing
equations
space
and
vibration
responses.
To
investigate
validate
effectiveness
predicting
fields
in
FSI
problems,
two-dimensional
laminar
vortex
shedding
fixed
cylinder
considered.
Furthermore,
applied
three-dimensional
vortex-induced
flexible
cylinder.
Using
SINDy
analyze
responses,
are
found
be
correlated
with
wake
patterns,
revealing
underlying
mechanism.
present
work
significant
step
toward
establishment
machine
learning-based
models
complex
phenomena,
discovery
physics,
real-time
control.
Physics of Fluids,
Journal Year:
2022,
Volume and Issue:
34(11)
Published: Oct. 22, 2022
While
it
is
known
that
rigid
splitter
plates
play
significant
roles
in
flow
control,
the
exact
of
them
flow-induced
vibration
(FIV)
have
not
been
systematically
investigated.
This
has
motivated
present
work
to
experimentally
investigate
FIV
a
cylinder
equipped
with
an
upstream
plate
(USP),
downstream
(DSP),
and
symmetrically
arranged
water
tunnel
Reynolds
number
1100–7700.
The
length
range
L*
=
0–3.6
(L*=L/D,
L
length,
D
diameter).
response
characteristics,
vortex
evolution,
fluid
force,
pressure
fields
are
thoroughly
analyzed.
Both
USP
DSP
can
succeed
oscillation
mitigation
drag
reduction.
However,
dramatic
galloping
observed
for
0.4–3.2.
low-pressure
region
forms
near
beneficial
trigger
galloping.
For
USP,
only
vortex-induced
found,
transition
branches
corresponds
variation
frequency
phase
jumps
total
transverse
force
force.
mode
from
2S
2P
disappears
long
length.
Flow
visualization
reveals
induced
by
alters
shedding.
Furthermore,
high-pressure
tip
yielding
obstructive
suppresses
growth
oscillation.
With
combination
DSP,
weak
excited
narrow
1.0–1.8,
linear
increase
also
broken
due
existence
USP.
Physics of Fluids,
Journal Year:
2022,
Volume and Issue:
34(8)
Published: July 22, 2022
A
frequency
capture
phenomenon
in
which
the
dominant
response
of
downstream
cylinder
is
same
as
that
upstream
despite
differences
their
physical
characteristics
was
recently
experimentally
identified.
The
mechanism
this
investigated
by
flow
around
two
cylinders
with
unequal
diameters
undergoing
flow-induced
vibrations
(FIV)
using
open-source
code
OpenFOAM.
Two
FIV
systems,
a
large
stationary/vibrating
and
vibrating
cylinder,
are
used
for
simulation.
free
to
vibrate
both
in-line
cross-flow
directions.
forgetting
factor
least
squares
algorithm
applied
time-varying
excitation
analysis.
Simulation
results
show
has
larger
amplitude
contains
multi-frequency
components
than
vortex-induced
vibration
an
isolated
making
its
trajectory
more
complicated.
Simulations
confirm
induced
action
shedding
vortex
on
cylinder.
energy
transfers
from
vorticity
structure
when
occurs.
comprises
significant
component
Physics of Fluids,
Journal Year:
2023,
Volume and Issue:
35(4)
Published: April 1, 2023
This
study
focuses
on
the
aerodynamic
nonlinearity
and
flow
field
phenomenology
of
structure-motion-induced
dynamics
in
fluid–structure
interactions
(FSI),
which
is
essential
for
response
prediction.
Through
dynamic-meshing
large-eddy
simulations
with
near-wall
resolution,
nonlinear
damping
still
wind
has
been
isolated
by
forced
vibration,
its
phenomenological
characteristics
physical
mechanisms
have
analyzed.
The
results
show
that
can
account
up
to
30%
total
damping,
cannot
be
ignored
also
reveals
three-dimensional
vorticity
vary
nonlinearly
structure
motion,
leading
hysteresis
effect
between
forces
displacement.
Furthermore,
in-depth
analysis
discloses
eight
types
coherent
substructures,
including
Stick,
Phone,
Bowknot,
Crutch,
Droplet,
Bat,
Horn,
Flag
are
solely
induced
structural
motion.
Insights
into
these
substructures'
formation,
evolvement,
dissipation,
superposable
magnitude
disclosed.
research
offers
a
new
perspective
understanding
nature
FSI,
serving
as
reference
various
FSI
applications,
bridges,
high-building
design,
other
related
fields.
Journal of Fluid Mechanics,
Journal Year:
2024,
Volume and Issue:
978
Published: Jan. 5, 2024
We
present
a
systematic
study
to
investigate
the
fluid–structure
interaction
(FSI)
of
subaqueous
spherical
pendulums
with
several
solid-to-fluid
mass
ratios
$m^*\in
[1.14,
14.95]$
and
corresponding
Reynolds
numbers
up
$\textit
{Re}\sim
10^4$
.
A
digital
object
tracking
(DOT)
method
was
employed
track
oscillating
pendulum
spheres
whereas
time-resolved
3-D
particle
velocimetry
(tr-3D-PTV)
used
measure
flow
field
around
spheres.
The
data
obtained
from
coupling
two
measuring
techniques
provide
novel
insights
into
dynamics
sphere
oscillations,
instantaneous
pressure
fluctuations
related
vortex
shedding
way
they
are
influenced
by
wake
interactions.
Namely,
we
show
that
during
downward
motion
spheres,
rings
shed
off
which,
in
turn,
induce
short-lived
propulsion
and,
subsequently,
distinct
deceleration.
Further,
measured
improve
an
existing
basic
model
motion,
which
has
significant
discrepancies
for
period
peak
amplitude
predictions.
did
this
incorporating
vortex-induced
drag
term
equation.
Finally,
improved
equations
shown
be
capable
predicting
high
accuracy,
investigated
range
$m^*$
thus
extends
current
understanding
fluid
dynamic
mechanisms
such
as
added
mass,
nonlinear
drag,
dynamics.
Journal of Fluid Mechanics,
Journal Year:
2025,
Volume and Issue:
1007
Published: March 24, 2025
We
study
the
response
of
a
flexible
prism
with
square
cross-section
placed
in
cross-flow
through
series
experiments
conducted
at
increasing
flow
velocities.
show
that
as
reduced
velocity
(a
dimensionless
also
depends
on
natural
frequency
structure)
is
increased,
undergoes
vortex-induced
vibration
(VIV)
its
first
mode,
which
then
transitions
to
VIV
second
mode
and
third
mode.
In
these
ranges,
shedding
synchronised
oscillation
frequency,
oscillations
are
mainly
transverse
(cross-flow
–
CF)
direction.
As
we
keep
velocity,
observe
linear
increase
amplitude
torsional
prism,
resembling
galloping.
This
causes
an
amplitudes
CF
inline
(IL)
while
structural
still
excited
A
transition
fourth
observed
higher
velocities,
reduces
IL
amplitudes,
reach
plateau.
After
this
plateau
reached
oscillations,
galloping
response,
results
large-amplitude
both
directions.
The
velocities
accompanied
by
oscillations.
Mathematics,
Journal Year:
2025,
Volume and Issue:
13(9), P. 1387 - 1387
Published: April 24, 2025
This
paper
introduces
an
efficient
and
automated
computational
framework
integrating
Python
scripting
with
Abaqus
finite
element
analysis
(FEA)
to
investigate
the
structural
behavior
of
long
free-spanning
submarine
pipelines
equipped
buoyancy
modules.
A
comprehensive
parametric
study
was
conducted,
involving
1260
pipeline
models,
successfully
performed
a
wide
range
parameters,
including
length
(lp=
100,
200,
300
m),
radius
(rp=
0.3,
0.4,
0.5
thickness,
type
fluid,
support,
load
ratio
(LR=
0.2,
0.6,
0.8,
1),
number
modules
(n=
0,
1,
2,
3,
5,
7,
9)
its
(lb=1/10·lp).
The
included
verification
process,
providing
presented
framework.
results
demonstrate
excellent
agreement
analytical
numerical
solutions,
validating
accuracy
robustness
proposed
indicates
that
deformation
natural
frequency
are
highly
sensitive
variations
in
arrangements,
geometry,
conditions,
whereas
normalized
mode
shapes
remain
largely
unaffected.
Practical
implications
include
ability
rapidly
optimize
module
placements,
reducing
resonance
risks
from
vortex-induced
vibrations
(VIVs),
thus
enhancing
preliminary
design
efficiency
safety.
developed
approach
advances
existing
methods
by
significantly
complexity
enabling
extensive
analyses,
making
it
valuable
tool
for
designing
stable,
cost-effective
offshore
systems.
