Journal of Physics Conference Series,
Journal Year:
2024,
Volume and Issue:
2854(1), P. 012008 - 012008
Published: Oct. 1, 2024
Abstract
Large-scale
tubular
pumps
are
widely
used
in
the
fields
such
as
low-head
agricultural
irrigation,
water
diversion
project
and
urban
drainage.
For
this
pump
type,
rotation
axis
is
perpendicular
to
gravity
direction,
resulting
operation
instability
risks
induced
by
constant
static
pressure
difference.
However,
due
large
size
of
prototype
difficulty
field
tests,
there
currently
a
lack
on-site
monitoring
data,
which
makes
it
difficult
truly
understand
actual
large-scale
provide
engineering
experience
with
direct
guidance
for
similar
projects.
To
fill
research
gap,
paper
takes
largest
shaft-well
China
an
example,
carried
out.
On
one
hand,
distribution
characteristics
stability
indexes
fluctuations,
vibrations
shaft
swings
quantified,
proved
that
performance
cannot
be
estimated
only
hydraulic
model
experiments.
other
potential
addressed
phenomenon
polarization
oscillation,
low-speed-induced
dry
friction
bearing
shells,
cantilever-induced
bending
deformation
reflected,
should
paid
more
attention
future
development.
These
results
can
valuable
safe
stable
tubulars.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(3)
Published: March 1, 2025
A
kind
of
flow
distortion
is
found
in
the
design
and
application
so-called
tubular-flow
fish-friendly
pump,
which
possesses
a
highly
twisted
blade
leading
edge
for
reducing
fish
damage.
It
named
as
hub
vortex
(LEHV)
has
closer
relationship
with
instability
energy
loss
compared
to
well-known
tip
leakage
(TLV).
Numerical
experimental
investigations
are
implemented
typical
terms
evolution
LEHV
size
strength,
well
vortex-induced
low
pressure
loss.
The
divided
into
four
stages,
namely
inception,
radial
development,
alternation
rotation
direction,
detachment.
dynamics
exhibit
distinct
periodicity
varying
intensity
position
due
fluctuation
rotating
pump.
Further
results
on
reveal
that
volume
near
much
larger
than
under
multiple
conditions,
indicating
cavitation
inception
more
likely
occur
hub,
seems
different
from
common
sense
appears
initially
at
tip.
Moreover,
it
plays
significant
role
causing
TLV
wake
formed
by
interaction
between
causes
considerable
impeller
exit.
This
study
will
provide
scientific
guidance
optimization
strategies
pump
improve
hydraulic
performance
stability.
Energy Science & Engineering,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 21, 2025
ABSTRACT
The
investigation
into
the
internal
flow
characteristics
of
bulb
tubular
pump
device
has
important
practical
significance
for
improving
both
optimal
design
and
operation
stability.
This
paper
uses
different
RANS/LES
turbulence
models
to
conduct
numerical
simulation
research
on
model
device,
specifically
focusing
differences
in
under
small
stall
condition
0.5
Q
des
1.0
.
macroscopic
energy
are
verified
through
experiment
tests,
revealing
that
DDES
provides
better
predicted
hydraulic
performance
conditions.
difference
low
conditions
is
mainly
due
degrees
turbulent
field
analysis,
while
analysis
degree
high‐efficiency
rate
with
uniform
remains
similar.
vortex
identification
method
Omega
used
visualize
structure
time‐averaged
field,
uncovering
large‐scale
structures
conditions,
blending
offering
superior
resolution
structures.
Furthermore,
deduces
calculation
pulsation
entropy
production
based
SST
formula.
A
comprehensive
local
power
loss
main
flow‐passing
components—impeller,
diffuser,
bulb—reveals
blades
wall
surfaces
contributors
increase
losses.
comparison
shows
more
accurate
predictions
visualizing
characteristics.
Physics of Fluids,
Journal Year:
2023,
Volume and Issue:
35(10)
Published: Oct. 1, 2023
The
energy
performance
and
efficiency
of
Pelton
turbine
units
is
the
focus
attention
in
engineering.
countertorque
bucket
during
operation
will
affect
above
indicators
unit.
However,
there
still
a
lack
systematic
research
on
generation
mechanism
control
strategies.
Numerical
simulation
experimental
were
conducted
turbine.
It
was
found
that
generated
initial
contact
stage
between
jet
suction
surface
bucket.
At
this
time,
acts
tip
bucket,
generating
force
opposite
direction
bucket's
rotation,
resulting
countertorque.
A
geometric
optimization
method
proposed,
which
suppresses
by
controlling
inclination
angle
As
decreases,
countertorque,
pressure,
circumferential
force,
entropy
production
rate
are
effectively
controlled.
Compared
to
original
scheme,
optimal
scheme
reduces
maximum
49.33%
improves
unit
0.57%.
Journal of Physics Conference Series,
Journal Year:
2024,
Volume and Issue:
2707(1), P. 012022 - 012022
Published: Feb. 1, 2024
Abstract
The
guide-vane
cone
diffusion
is
a
typical
structural
difference
between
an
axial-flow
pump
and
tubular
pump,
which
shown
as
low
diffusivity
high
respectively,
but
it
still
unclear
how
this
affects
the
vortex
characteristics
in
stator
corner
separation
flows.
In
paper,
comparative
study
of
flows
was
conducted,
effects
on
vortical
structures
were
clarified.
Firstly,
for
apparent
features,
compared
with
diffusivity,
horn-like
has
features
smaller
scale,
weaker
swirling
strength,
shorter
evolution
cycle
lower
pressure
fluctuations.
Secondly,
dynamics
mechanism,
can
cause
additional
energy
recovery,
leads
to
higher
adverse
gradients,
so
easier
induce
shroud
backflow
near
suction
surface.
coupled
flow
field
main
flow,
namely
hub
backflow,
streamwise
periodic
oscillation
function
gradient
ω
S
·▽(▽
p/ρ
)
found,
induces
unique
vortex-street-like
distributions
deformational
vorticity
rigid
R
.
This
physical
effect
causes
mutual
competition
opposite
side.
It
originating
from
that
greatly
suppresses
development
pump.
