IOP Conference Series Earth and Environmental Science,
Год журнала:
2024,
Номер
1411(1), С. 012034 - 012034
Опубликована: Ноя. 1, 2024
Abstract
Centrifugal
pumps
as
turbines
(PATs),
economically
feasible
and
energy-saving
technologies,
are
commonly
used
in
energy-intensive
industrial
operations.
The
entropy
production
theory
was
applied
to
study
a
forward-curved
blade
PAT
by
experimental
numerical
simulation
techniques.
findings
demonstrate
that
the
hydraulic
efficiency
reaches
75.65%
at
design
flow
rate.
impeller
volute
where
majority
of
energy
loss
occurs.
In
low-flow
condition,
shear
force
significant
velocity
gradient
primary
causes
condition.
high-flow
shock
is
greater,
increasing
turbulent
power.
There
very
little
correlation
between
rate
draft
tube,
mainly
from
incoming
state
viscosity
effect
tube
wall.
This
helps
understand
conversion
mechanism
PAT,
which
has
reference
value
for
efficient
economical
operation
PAT.
Energies,
Год журнала:
2025,
Номер
18(7), С. 1642 - 1642
Опубликована: Март 25, 2025
In
order
to
study
the
influence
of
split
blades
on
turbine
force
characteristics
and
fluid–structure
coupling
pumps,
this
paper
selected
IS
80-50-315
centrifugal
pump,
used
as
a
reverse-acting
hydraulic
turbine,
research
object,
optimized
original
pump-acting
impeller,
adopted
different
combinations
long
short
blades.
Based
SIMPLE
algorithm
RNG
k–ε
turbulence
model,
complete
three-dimensional
unsteady
numerical
simulation
was
conducted
internal
flow
field
pump-turbine.
The
results
show
that
reduce
radial
axial
forces.
deformation
patterns
rotor
components
in
two
pump
types
models
were
similar,
with
gradually
decreasing
from
inlet
outlet
impeller.
equivalent
stress
distribution
law
has
also
been
found
be
maximum
occurring
at
connection
between
front
rear
cover
plates
minimum
area
impeller
shaft
diameter
shaft.
blade
model
smaller
than
those
model.
Background:Fontan
completion
is
the
last
stage
of
univentricular
repair,
which
drains
inferior
vena
cava
against
gravity
to
a
higher-pressure
pulmonary
arterial
circulation.
The
passivity
and
anti-gravity
nature
this
circulation
render
failing
Fontan,
not
an
uncommon
encounter,
twenty
years
ago,
Rodefeld
colleagues,
decided
explore
feasibility
vascular
pumps
support
passive
Fontan
circulation,
since
then,
trials
are
still
ongoing,
we
aimed
through
review
wrap
up
results
these
trials.
Methods:A
literature
has
been
conducted,
identify
any
in
vivo
or
vitro
trial
assist
device.
Several
outcome
parameters
determined
whether
will
be
included
review,
including,
flow
rate
pump
if
applicable,
number
compressions
per
minute
compression
device
used,
resultant
rate,
superior
pressures,
associated
with
each
setting
respective
device,
evidence
hemolysis
clotting
within
circuit.
Results:A
total
ten
have
included,
23
different
settings.
Three
designs
identified,
out
two
fall
design,
namely
connecting
chamber
intravascular
designs;
only
one
explored
possible
use
commonest
design
encountered
in-vivo
was
(67%).
No
reports
significant
thrombosis
were
found.
An
increasing
beyond
5L/min
negative
upstream
pressure
SVC,
while
did
display
limitation.
Conclusion:Univentricular
heart
patients
relatively
small
population,
very
extensive
needs,
despite
trials,
no
study
yet
concluded
optimal
settings
for
In
identified
that
remains
most
practical
due
its
easy
mode
insertion,
it
faced
limitation
risk
resistance.
There
long
way
conclude
as
other
such
devices
fully
studied.
CFD letters,
Год журнала:
2024,
Номер
17(3), С. 148 - 166
Опубликована: Окт. 22, 2024
As
global
power
demand
increases,
hydropower
plants
often
must
operate
beyond
their
optimal
efficiency
to
meet
grid
requirements,
leading
unstable,
high-swirling
flows
under
various
load
conditions
that
can
significantly
shorten
the
lifespan
of
turbine
components.
This
paper
presents
an
in-depth
computational
study
on
performance
and
dynamics
a
pump-turbine
operating
80%
partial
load,
focusing
formation
impact
vortex
ropes.
Large
Eddy
Simulation
(LES)
was
utilized
model
turbulent
flow,
revealing
complex
patterns
significant
pressure
fluctuations.
A
pronounced
straight
rope
identified
in
draft
tube,
maintaining
its
trajectory
core
size
consistently,
profoundly
affecting
flow
characteristics.
Pressure
fluctuations
were
observed
at
cross-sectional
planes,
with
peaks
troughs
primarily
near
runner,
indicating
areas
prone
instability.
The
standard
deviation
ranged
from
4.51
5.26
along
tube
wall
4.27
4.97
axial
center,
highlighting
unsteady
flow.
Moreover,
frequency
corresponding
highest
amplitude
coefficient
spectrographs
remained
consistent
approximately
9.93
9.95,
emphasizing
persistent
influence
dynamics.
These
affected
generation,
which
29.1
kW,
accounting
for
about
3%
total
generated
power,
underscoring
critical
operational
stability
pump-turbines
off-design
conditions.
provides
essential
insights
vital
enhancing
design
strategies
these
turbines,
ensuring
more
efficient
reliable
energy
production
face
increasing
demands.
