Flow-induced
vibration
(FIV)
is
an
important
phenomenon
that
frequently
occurs
in
practical
scenarios,
such
as
chemical
towers,
chimneys,
risers,
and
offshore
structures.
Employing
effective
methods
to
control
FIV
crucial
for
ensuring
the
safety
long-term
operation
of
engineering
Due
limitations
current
passive
techniques
adequately
suppressing
wake-induced
galloping
(WIG)
tandem
cylinders,
seven
different
types
helical
strakes
with
varying
heights
G,
pitches
P,
cross-sectional
shapes
(square
“S”,
involute
“I”,
D-shaped
“D”)
were
designed.
Experimental
conducted
a
wind
tunnel
investigate
dynamic
responses
cylinders
(m*ξ=0.09)
at
spacings,
resulting
three
modes.
The
amplitude,
frequency,
three-dimensional
computational
fluid
dynamics
(CFD)
simulations
performed
analyze
configurations
strakes.
It
was
discovered
can
effectively
suppress
multi-frequency
instability
bare
cylinders.
For
speeds
U
<
6m/s,
"S"
strake
achieved
suppression
efficiency
up
665%.
Moreover,
larger
pitch
led
less
flow
interference
on
spanwise
height,
significant
effects.
Furthermore,
it
observed
has
stronger
influence
boundary
layer
formation
compared
"D"
strake.
This
results
weaker
shedding
vortices
separation
point
due
absence
negative
pressure
gradient
shear
layer,
thus
revealing
mechanisms
cross-sections
cylinder
dynamics.
Physics of Fluids,
Journal Year:
2023,
Volume and Issue:
35(8)
Published: Aug. 1, 2023
A
circular
cylinder
attached
by
a
rigid
splitter
plate
of
different
lengths
was
tested
to
examine
its
effects
on
the
control
flow-induced
vibration.
Tests
were
carried
out
in
closed-loop
water
channel.
diameter
D
=
20
mm
and
mass
ratio
m*
≈
50
installed
oscillate
transverse
direction.
wide
range
length
considered,
i.e.,
L/D
0–3.5,
at
reduced
velocity
Ur
1–25
Reynolds
number
Re
800–11
000.
Numerical
simulations
also
conducted
reveal
flow
structures
associated
with
vibration
modes
observed
experiment.
It
is
found
that,
as
increases
from
0
0.25,
peak
value
oscillation
amplitude
appears
higher
velocities.
When
continues
rise,
galloping-type
oscillations
occur
0.5
0.75.
The
transition
stage
has
been
1.0.
Oscillation
then
significantly
suppressed
when
larger
than
1.5.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(1)
Published: Jan. 1, 2025
This
experimental
study
investigates
a
flexible
circular
cylinder's
flow-induced
vibrations
(FIV)
with
an
attached
splitter
plate.
The
system's
dynamic
response
was
analyzed
for
three
plate
widths:
1D,
2D,
and
3D,
where
D
is
the
diameter,
compared
to
bare
cylinder.
At
low
reduced
velocities,
cylinder
exhibited
oscillations
in
its
first
two
bending
modes,
presence
of
resulted
up
70%
reduction
oscillation
amplitudes.
higher
amplitude
1D
remained
below
that
In
contrast,
amplitudes
increased
monotonically
2D
3D
plates,
reaching
four
times
cylinder,
respectively.
Multi-frequency
were
observed
wider
plates.
Flow
field
analysis,
incorporating
both
quantitative
qualitative
methods,
along
proper
orthogonal
decomposition
flow
field,
identified
distinct
FIV
types:
experienced
galloping
type
widths
vortex-induced
vibration
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(3)
Published: March 1, 2025
Flow
control
of
cylinders
aimed
at
drag
reduction
or
vibration
suppression
has
been
widely
studied.
Sweeping
jet
is
a
novel
flow
method
that
applied
to
airfoil
and
other
bluff
bodies.
This
paper
numerically
investigates
the
effects
sweeping
jets
on
cylinder
Reynolds
number
5
×
104
using
large
Eddy
simulation.
Various
parameters
such
as
angle,
momentum
coefficient,
arrangement
configuration
fluidic
oscillators
are
examined
for
their
influence
effectiveness.
The
results
demonstrate
significantly
reduce
cylinder's
drag,
mitigate
lift
fluctuations,
suppress
vortex
shedding,
extend
length
recirculation
region.
optimal
angle
70°,
coefficient
3.4
10−3,
reaches
maximum
47%,
while
standard
deviation
decreases
by
92.2%.
As
increases,
factor
(defined
ratio
reduced
baseline
drag)
rises.
However,
when
exceeds
10-3,
rate
significantly,
accompanied
changes
in
wake
pattern.
Besides,
density
also
plays
crucial
role
Furthermore,
interaction
between
incoming
examined.
upstream
separation
point
exchange
with
boundary
layer,
enhancing
stability
suppressing
separation.
closer
point,
more
effective
suppression.
