Numerical Heat Transfer Part A Applications,
Год журнала:
2022,
Номер
83(11), С. 1220 - 1238
Опубликована: Авг. 3, 2022
In
this
article,
a
nonlinear
LRN/DES
turbulence
model
is
proposed
by
introducing
Reynolds
stress
and
scale
resolution
simulation
methods
to
address
the
contradiction
between
computational
cost
accuracy
of
existing
models
in
wind
buffeting
noise
simulations.
After
verifying
feasibility
backward-facing
step
flow,
carried
out
based
on
simple
cavity
model.
By
comparing
with
several
commonly
used
experimental
results,
it
found
that
simulates
frequency
sound
pressure
level
most
accurately,
capture
flow
field
also
closest
result.
Mechanical Systems and Signal Processing,
Год журнала:
2023,
Номер
208, С. 110959 - 110959
Опубликована: Ноя. 27, 2023
This
work
examines
the
active
control
of
vehicle
buffeting
noise
using
a
dielectric
barrier
discharge
plasma
actuator
(DBD-PA).
First,
characteristics
cavity
under
different
inflow
wind
speeds
are
established
through
tunnel
test,
and
effectiveness
measurement
results
is
verified.
Various
types
layouts
designed
based
on
specific
combinations
parameters,
interval
optimization
algorithm
used
to
identify
layout
type
actuators
that
have
best
equalization
effect
speeds.
The
experimental
regarding
show
frequency
peak
value
sound
pressure
level
increase
with
increasing
speed.
overall
reverse
span-wise
DBD-PA
(SDBD-PA)
better
than
positive
layout.
Consequently,
effects
SDBD-PA
decrease
in
front,
rear,
oblique
directions.
A
DBD
vortex
generator
(DBD-VG)
has
no
when
it
arranged
front
but
certain
rear.
longer
DBD-VGs.
running
at
incoming
as
follows:
reverse-front-SDBD-PA
long-rear-DBD-VG
can
achieve
noise.
average
reduction
values
5.26
dB
4.42
dB,
respectively,
maximum
7.48
5.79
respectively.
Journal of low frequency noise, vibration and active control,
Год журнала:
2023,
Номер
42(4), С. 1718 - 1732
Опубликована: Июнь 21, 2023
The
aim
of
this
study
is
to
investigate
the
effectiveness
and
mechanism
wind
buffeting
noise
suppression
using
a
new
bionic
structure
inspired
by
quiet
flight
owls.
Firstly,
schemes
based
on
NACA0012
wing
with
two
sinusoidal
leading-edge
serrations
one
straight
curve
are
used
in
cavity
after
verifying
simulation.
Then,
results
three
compared
analyzed.
It
found
that
surface
ridges
can
suppress
effectively.
In
particular,
scheme
wavelength
λ
=
0.24
c
(chord
length
c)
significantly
reduce
resonance
energies
above
21
dB
over
wide
range
speeds.
Furthermore,
reveals
scheme,
only
negative
pressure
core
moves
opening
hits
trailing
edge,
which
reduces
fluctuation
cavity.
boundary
layer
thickness
(BLT)
also
fluctuates
span
under
influence
serration
ridge,
favorable
for
suppressing
noise.
However,
effect
not
solely
related
BLT
at
edge
but
influenced
minimum
point.
Therefore,
if
has
certain
intensity
span,
close
smooth
airfoil
significant.
River Research and Applications,
Год журнала:
2024,
Номер
40(3), С. 425 - 435
Опубликована: Янв. 29, 2024
Abstract
The
three‐dimensional
flow
velocities
within
the
typical
pool
chamber
of
rectangular
fishway
were
measured
in
a
vertical
slit
bottom‐hole
combination
by
hydraulic
model
test
using
an
acoustic
Doppler
velocimeter
(ADV).
This
was
aimed
to
analyze
effect
eddy
structures
on
fish
migration.
Based
this,
numerical
simulation
study
conducted
Reynolds
mean
(RNG
k‐ε
)
and
large
(LES).
Additionally,
omega
(
Ω
identification
method
used
identify
structure
dissect
characteristics
water
body
chamber.
findings
revealed
that
longitudinal
velocity
dominated
lower
bottom
layer
pond.
Moreover,
middle
upper
layers
more
turbulent
there
is
phenomenon
backflow
upstream,
at
orifice
divergent
jet
with
main
slightly
right
bank,
forming
two
vortices
opposite
directions
both
sides
orifice.
passage
mainly
displayed
vortex
structure,
which
can
effectively
slow
down
provide
resting
place
for
migratory
fish.
accurately
inside
field.
Lobe
pumps
are
used
in
many
different
sectors
because
of
their
versatility
and
effectiveness
for
managing
multiphase
flows.
In
this
study,
three-dimensional
unsteady
numerical
simulations
performed
to
evaluate
the
vortex
cavitation
phenomenon
these
pumps.
The
work
combines
dynamic
meshing
techniques,
advanced
recognition
methods,
a
full
model
provide
insight
into
genesis,
evolution,
influence
on
pump
performance.
results
study
demonstrate
that
under
high-speed
high-pressure
conditions,
flow
occurs
at
edge
rear
rotor
lobe
suction
chamber
pump,
resulting
production
cavitation.
Cavitation
is
most
strong
core
vortex,
while
degree
gradually
diminished.
gas
volume
fraction
reduces
from
0.135
0.0832,
makes
pressure
decrease
1.055
1.02
MP.
process
development,
removal
cyclic.
At
levels
cavitation,
pulsation
outlet
flow,
pressure,
radial
force
increases
with
increasing
Periodic
leads
periodic
changes
output
rate,
force,
axial
force.
