This
work
presents
numerical
investigations
of
flow-induced
rotation
three
different
polygonal
prisms,
including
triangular,
square,
and
pentagonal
ones.
Taking
into
account
the
torsional
stiffness
damping,
response
is
examined
in
a
reduced
velocity
range
Ur
=
3–15
at
Re
100.
Four
distinct
oscillating
regimes
associated
vortex
shedding
modes
are
identified:
2S
mode
bifurcated-steady
regime
(3
≤
<
5
10
15
for
triangular
prism,
7
11
square
prism),
4S
bifurcated-unsteady
(12
6S
non-bifurcated
(5
quasi-static
8
whole
prism).
Moreover,
competitions
between
pressure-induced
torque
shear-induced
vary
these
four
regimes.
Specifically,
dominant
component
By
contrast,
two
kinds
torques
owning
nearly
equal
proportions
possess
same
opposite
sign
regimes,
respectively.
The
root-mean-squared
rotary
angle
(θrms)
depends
on
cross-sectional
shape
velocity.
θrms
prism
suddenly
drops
to
level
freely
rotating
case
before
rising
stages.
starts
rotate
violently
when
it
enters
regime.
For
vortex-induced
vibration-like
observed.
Due
general
largest
group,
followed
by
sequence.
Ocean Engineering,
Год журнала:
2023,
Номер
272, С. 113617 - 113617
Опубликована: Фев. 16, 2023
This
paper
reviews
research
in
ocean
engineering
over
the
last
50+
years
with
aim
to
(I)
understand
technological
challenges
and
evolution
field,
(II)
investigate
whether
studies
meet
present
global
demands,
(III)
explore
new
scientific/engineering
tools
that
may
suggest
pragmatic
solutions
problems,
(IV)
identify
management
gaps,
way
forward.
Six
major
divisions
are
identified,
namely
Ocean
Hydrodynamics,
Risk
Assessment
Safety,
Climate
Geophysics:
Data
Models,
Control
Automation
Ocean,
(V)
Structural
Engineering
Manufacturing
for
(VI)
Renewable
Energy.
As
much
as
practically
possible
sub-divisions
of
field
also
identified.
It
is
highlighted
topics
dealing
renewable
energy,
control
path
tracking
ships,
well
computational
modelling
wave-induced
motions
growing.
Updating
forecasting
energy
resources,
developing
methods
wave
generation,
introducing
novel
optimised
converters
potential
opportunities.
Ongoing
follow
needs
environmentally
friendly
energies,
though
engineering-based
often
tend
overlook
longer-term
influence
climate
change.
Development
exploitation
focus
on
continuum
mechanics
problems
remain
relevant.
Notwithstanding
this,
machine
learning
attracting
attention
researchers.
Analysis
COVID-19
transmission
onboard
rarely
conducted,
3D
printing-based
still
need
more
from
Ocean Engineering,
Год журнала:
2023,
Номер
285, С. 115389 - 115389
Опубликована: Июль 22, 2023
Recent
studies
of
passive
and
active
flow
control
devices
for
suppressing
vortex-induced
vibration
(VIV)
circular
cylinders
are
reviewed
extensively.
The
include
splitter
plates,
rods,
helical
strakes,
porous
layers
rough
surfaces,
the
jet
flow,
rotating
cylinder,
rods.
A
plate
with
a
certain
length
can
suppress
VIV
but
very
long
cause
galloping.
One
or
two
rods
located
downstream
separation
points
VIV.
suppression
using
three
to
eight
were
also
studied
increasing
rod
number
improve
effectiveness.
Porous
sufficient
porosity
thickness
achieve
nearly
full
generally
have
better
effect
than
surfaces.
Helical
strakes
well
when
its
pitch
ratio
is
greater
10
height
0.2
times
cylinder
diameter.
If
external
energy
used,
suppression.
Rotating
in
one
direction
but,
another
direction,
enhance
Some
important
conclusions
highlighted
section
4
this
paper.
Experimental
studies
dealing
with
the
wake
of
isolated
stationary
bluff
bodies
are
reviewed.
After
briefly
recalling
pioneering
works
in
this
domain,
paper
focuses
on
recent
research
conducted
latest
experimental
methods
and
techniques.
The
review
encompasses
a
range
topics,
including
effects
body
geometry
(non-circular
cross
sections
non-uniformity
spanwise
direction),
steady
unsteady
(periodic
non-periodic)
inflow
conditions,
surface
proximity
(rigid
wall,
confinement,
water
free
surface)
non-Newtonian
fluids.
Focus
is
brought
to
flow
physics
wakes,
especially
complex
three-dimensional
oscillatory
behaviors
induced
by
periodic
vortex
shedding
phenomenon.
aims
offer
critical
systematic
new
knowledge
findings
subject
area,
as
well
most
frequently
adopted
also
helps
identifying
gaps
literature
that
need
be
addressed
future
investigations.
In
this
paper,
we
conducted
a
selective
review
on
the
recent
progress
in
physics
insight
and
modeling
of
flexible
cylinder
flow-induced
vibrations
(FIVs).
FIVs
circular
cylinders
include
vortex-induced
(VIVs)
wake-induced
(WIVs),
they
have
been
center
fluid-structure
interaction
(FSI)
research
past
several
decades
due
to
rich
engineering
significance.
First,
summarized
new
understanding
structural
response,
hydrodynamics,
impact
key
properties
for
both
isolated
multiple
cylinders.
The
complex
FSI
phenomena
observed
experiments
numerical
simulations
are
explained
carefully
via
analysis
vortical
wake
topology.
Following
up
with
critical
future
questions
address,
discussed
advancement
artificial
intelligent
machine
learning
(AI/ML)
techniques
improving
FIVs.
Though
early
stages,
AL/ML
shown
success,
including
auto-identification
VIV
features,
physics-informed
neural
network
solving
inverse
problems,
Gaussian
process
regression
automatic
adaptive
experiments,
multi-fidelity
prediction
accuracy
quantifying
uncertainties.
These
preliminary
yet
promising
results
demonstrated
opportunities
challenges
today's
big
data
era.
Ocean Engineering,
Год журнала:
2022,
Номер
261, С. 111611 - 111611
Опубликована: Авг. 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.
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.
