Hydro-acoustic optimization of propellers: A review of design methods
Applied Ocean Research,
Год журнала:
2024,
Номер
151, С. 104158 - 104158
Опубликована: Авг. 17, 2024
In
recent
years,
the
escalation
of
anthropogenic
noise
within
marine
environments
has
become
a
pressing
ecological
concern.
Despite
proliferation
guidelines
aimed
at
mitigating
this
issue,
their
adoption
remains
non-compulsory.
The
International
Maritime
Organization
(IMO)
advocates
for
reduction
through
refinement
propeller
design
and
heightened
research
to
curtail
acoustic
emissions,
ensuring
that
such
measures
do
not
compromise
propulsive
efficiency.
This
review
delves
into
array
strategies
devised
attenuate
pollution.
It
scrutinizes
methodologies
employed
evaluate
hydroacoustic
attributes
propellers,
including
experimental
computational
approaches.
Furthermore,
it
summarizes
techniques
in
multiobjective
optimization
which
involves
balancing
maximization
efficiency
against
minimization
emission.
findings
highlight
necessity
comprehensive,
interdisciplinary
approach
encompassing
cavitation
experiments
advanced
numerical
simulations.
field
optimization,
traditional
reliance
on
genetic
algorithms
is
giving
way
neural
networks
surrogate
models
derived
from
fluid
dynamics
data,
particularly
when
addressing
complex,
nonlinear
phenomena
as
hydro-acoustics
cavitation.
Язык: Английский
Fast and accurate prediction of flow in multi-row cascade based on combined neural networks
Physics of Fluids,
Год журнала:
2025,
Номер
37(1)
Опубликована: Янв. 1, 2025
This
paper
proposes
a
fast
and
accurate
method
for
predicting
multi-row
cascade
flow
based
on
framework
of
combined
neural
networks.
The
primary
idea
this
is
to
decompose
the
whole-annulus
into
different
types
sub-regions,
prediction
surrogate
models
networks
are
constructed
these
sub-regions
in
rectangular
computational
domain
by
applying
coordinate
transformation
technique.
each
sub-region
then
combined,
continuity
at
interfaces
among
used
iteratively
compute
cascade.
main
advantages
proposed
include
reduced
dataset
generation
cost
network
training
through
spatial
decomposition,
as
well
ability
achieve
combining
sub-regions.
test
case
two-dimensional
stator-rotor
interaction
indicates
that
time
developed
approximately
5%
required
numerical
simulation,
with
over
99%
nodes
field
exhibiting
normalized
absolute
error
less
than
0.05.
approach
can
be
further
extended
three-dimensional
multi-stage
turbomachinery.
Язык: Английский
On energy conversion mechanism of a marine submerged waterjet
Physics of Fluids,
Год журнала:
2025,
Номер
37(3)
Опубликована: Март 1, 2025
The
submerged
waterjet
(SWJ)
is
a
novel
marine
propulsor
for
surface
ships,
which
shows
remarkable
energy
performances
in
mixed-use
profile.
Less
research
has
been
done
to
reveal
the
mechanisms
of
its
distinguished
and
propulsion
performances.
Based
on
flux
balance
theory,
this
paper
proposes
method
analysis
conversion
process
SWJ
system,
where
link
established
between
performance
quantitative
evolution
components
occurring
both
internal
external
flows
through
control
volume
system.
detailed
investigation
indicates
that
various
interactions,
among
rotor,
stator
duct,
exhibit
different
impacts
enhancing
overall
duct
majorly
changes
working
environment
rotor
from
flow
operation
ones.
After
adding
shaft
power
increases
sharply,
due
increased
pressure
distribution
domain.
Afterward,
system
can
experience
stronger
work
into
axial
kinetic
flux,
enables
have
greater
potential
generate
larger
thrust.
As
post-stator,
it
improves
open
water
efficiency
dominantly
enhancement
hydraulic
efficiency.
In
detail,
positive
impact
post-stator
mainly
achieved
by
increasing
proportion
promoting
transversal
ones
pump
inner
For
around
downstream
also
plays
significant
role
improving
hub
vortex
as
well
stability
tip
leakage
vortex.
A
more
stable
field
one
important
prerequisites
reducing
vibration
noise
Another
enhance
generating
additional
thrust
guide
vanes
reduce
drag
at
same
time.
Язык: Английский
Comparative study of tonal noise prediction methods for stator-rotor interaction
Ocean Engineering,
Год журнала:
2025,
Номер
335, С. 121706 - 121706
Опубликована: Июнь 3, 2025
Язык: Английский
Flow characteristics analysis of an ultrathin forward-curved multi-blade centrifugal fan
Engineering Applications of Computational Fluid Mechanics,
Год журнала:
2024,
Номер
19(1)
Опубликована: Дек. 12, 2024
The
ultrathin
centrifugal
fan,
widely
utilised
in
compact
electronic
devices
such
as
laptops,
is
characterised
by
numerous
forward-curved
blades
that
generate
high
static
pressure
and
flow
rates.
Despite
its
widespread
application,
the
dynamics
of
fans
remain
insufficiently
explored.
In
large-scale
turbomachinery,
boundary
layer
thickness
typically
negligible,
with
separation
being
primary
contributor
to
losses.
However,
loss
mechanisms
are
not
yet
well
understood.
This
study
addresses
these
gaps
investigating
entropy
production
associated
various
processes,
decomposing
generation
into
components
related
molecular
viscosity
eddy
viscosity.
Large
Eddy
Simulation
(LES)
employed
analyze
turbulent
characteristics
fans.
findings
indicate
thickness,
constituting
approximately
10%
volute
height,
substantial.
Viscous
dissipation
within
generates
2.85×10−4W/K
entropy,
whereas
contributes
1.16×10−5W/K,
underscoring
significant
impact
on
fan's
operational
efficiency.
To
further
investigate
turbulence
characteristics,
hot-wire
anemometry
measurements
were
conducted
obtain
energy
spectrum.
Moreover,
scale
fluctuations
derived
from
simulation
results
analyzed
frequency
domain,
revealing
low-frequency
linked
blade
surfaces,
while
high-frequency
shell.
insights
gained
this
field
analysis
can
inform
design
more
efficient
quieter
cooling
Язык: Английский
Entropy transport for quasi-one-dimensional flow
Physics of Fluids,
Год журнала:
2024,
Номер
36(7)
Опубликована: Июль 1, 2024
The
study
of
entropy
in
the
context
quasi-one-dimensional
flow
is
expanded
this
work.
Specifically,
a
new
transport
equation
derived
and
integrated
into
closed-form
algebraic
expression
for
change.
derivation
identifies
respective
components
change
valid
flows
with
an
arbitrary
combination
area
change,
heat
transfer,
friction.
irreversibility
identified
found
to
be
composed
frictional
dissipation,
irreversible
work
term
that
results
from
restriction
flows.
each
component
first
validated
using
several
canonical
(i.e.,
isentropic,
Fanno,
Rayleigh,
normal
shock).
A
unique
production
mechanism
producing
(e.g.,
Two
additional
cases,
sudden
expansion
contraction,
are
then
considered
show
sole
mechanism.
Finally,
simultaneous
friction
transfer
examined,
overall
decomposed
contributions
dissipation
terms.
In
all
net
newly
expressions
agrees
known
solutions
within
numerical
precision.
Язык: Английский