Forced vibration analysis of a spinning Timoshenko beam under axial loads by means of the 3-dimensional Green’s functions
International Journal of Solids and Structures,
Год журнала:
2025,
Номер
unknown, С. 113324 - 113324
Опубликована: Март 1, 2025
Язык: Английский
Sampled-data fuzzy modeling and control for offshore structures subject to parametric perturbations and wave loads
Ocean Engineering,
Год журнала:
2025,
Номер
326, С. 120908 - 120908
Опубликована: Март 12, 2025
Язык: Английский
Passive control of rotational response of a square cylinder with small circular rods
Physics of Fluids,
Год журнала:
2025,
Номер
37(4)
Опубликована: Апрель 1, 2025
This
work
proposed
a
passive
method
by
arranging
several
small
circular
rods
to
control
the
rotational
dynamics
of
square
cylinder.
Two-dimensional
numerical
investigations
were
conducted
at
low
Reynolds
number
120
and
in
wide
reduced
velocity
range
Ur
=
2–20.
Effects
rod
arrangement
as
well
gap
distance
between
cylinder
examined.
For
single
cylinder,
critical
6.5
is
identified.
Rotary
angles
remain
near
zero
2–6,
while
sharp
rise
occurs
6.5,
reaching
peak
38.05°
8,
after
which
it
slightly
declines.
The
frequencies
follow
two
different
growth
rates
before
velocity.
When
eight
are
evenly
arranged
around
rotary
structure
do
not
exceed
5°
90%
reductions
achieved
compared
with
showing
most
effective
suppression.
However,
associated
drag
coefficients
significantly
increased
due
projected
area
in-line
direction
frequent
separation
reattachment
behaviors.
Optimal
when
placed
windward
leeward
position,
helpful
reduce
local
high
pressure
recover
base
pressure,
respectively.
Bifurcation,
characterized
non-zero
time-averaged
angle,
appears
side-by-side
position.
After
bifurcation,
these
stay
below
causing
an
asymmetrical
configuration
thus
flow
distributions.
A
recommended
half
length
edge
under
across
entire
range,
indicating
perfectly
excellent
rotation
At
this
configuration,
no
vortex
shedding
field
stable
symmetry.
Язык: Английский
Role of cross-flow vibrations in the flow-induced rotations of an elastically mounted cylinder-plate system
Physics of Fluids,
Год журнала:
2024,
Номер
36(6)
Опубликована: Июнь 1, 2024
Vibration
and
rotation
represent
two
common
fluid–structure-interaction
phenomena,
which
can
occur
independently
or
concurrently.
While
extensive
research
has
been
conducted
on
individual
vibration/rotation
cases,
there
is
relatively
limited
literature
coupled
cases.
However,
it
crucial
to
recognize
that
responses,
such
as
those
observed
in
falling
leaves,
are
more
prevalent
both
natural
occurrences
engineering
scenarios.
Hence,
this
study
aims
investigate
the
influence
of
cross-flow
vibrations
flow-induced
rotations
an
elastically
mounted
cylinder-plate
system.
A
broad
range
rotational
reduced
velocities,
spanning
Uθ
=
2–18,
examined
across
four
distinct
vibrational
namely
Uy
5,
8,
12,
18.
Numerical
results
indicated
a
bifurcation
phenomenon,
wherein
deflects
non-zero
equilibrium
position,
occurs
at
high
values
Uy.
Four
response
modes
have
identified:
vibration-dominated,
rotation-dominated,
augmentation
(VIV-like),
(galloping-like)
mode.
These
exert
significant
phase
angles
between
rotary
angle
displacement
well
vortex
shedding
modes.
In
rotation-dominated
region,
VIV-like
galloping-like
exhibit
continuous
decreasing
trend,
consistent
level
180°
90°,
respectively.
Transitions
vibration
responses
result
sharp
increases
angles.
The
wake
flow
mode
demonstrates
2S
(two
single
vortices),
while
vibration-dominated
characterized
by
predominant
2T
triplets
vortices).
large
amplitudes
lead
increase
numbers
vortices,
presenting
2S,
2S*,
2P
pairs
vortices)
2P,
P
+
S
(one
pair
one
2P+S
where
2S*
consists
each
exhibiting
tendency
split
into
smaller
vortices
they
migrate
downward.
mechanism
behind
notable
amplification
rotation/vibration
elucidated.
Apart
from
pressure
difference
induced
shedding,
additional
driving
force
resulting
relative
motion
transverse
direction
contributes
total
torsional
force,
thereby
leading
responses.
Furthermore,
streamlined
profile
accounts
for
escalation
amplitudes.
Язык: Английский
Coupled response of flow-induced vibration and flow-induced rotation of a circular cylinder with a triangular fairing
Physics of Fluids,
Год журнала:
2024,
Номер
36(7)
Опубликована: Июль 1, 2024
In
this
paper,
a
numerical
simulation
investigation
is
carried
out
on
the
coupled
response
of
flow-induced
vibration
(FIV)
and
rotation
(FIR)
circular
cylinder
attached
with
triangular
fairing
at
low
Reynolds
number
Re
=
100.
The
primary
focus
impact
FIR
FIV.
response,
hydrodynamic
coefficient,
vortex
shedding
mode,
flow
field
characteristics
are
examined
for
fairings
within
vibrational
reduced
velocity
Ur
range
3–16
shape
angle
α
45°,
60°,
90°.
results
reveal
that
Ur,
all
three
considered
have
good
suppression
effect
Nevertheless,
galloping
emerges
as
increases
when
45°
60°.
contrast,
90°
presents
wider
lock-in
region.
rotatable
2-degree
freedom
(2-DoF)
has
better
performance
in
reduction
amplitude
coefficients.
2S
(two
single
vortices)
mode
mainly
occurs
vortex-induced
(VIV)
region,
while
2S–8S
(from
two
to
eight
vortices),
2P
pairs
2T
triplets
P
+
T
(a
pair
vortices
triple
modes
emerge
branch.
Moreover,
four
wake
structures
identified
according
variation
recirculation
region
migration
boundary
layer
separation
point.
Finally,
regions
drag,
lift,
highlighted
compared
bare
cylinder.
Язык: Английский