IOP Conference Series Earth and Environmental Science,
Journal Year:
2022,
Volume and Issue:
1079(1), P. 012025 - 012025
Published: Sept. 1, 2022
Abstract
The
powerplants
in
the
Himalayan
region
are
generally
subjected
to
hydro-abrasive
erosion.
deterioration
of
components
due
erosion
causes
reduction
performance,
changes
fluid
flow
pattern
and
even
breakdown
turbine.
In
present
work,
Bhilangana-III
powerplant
Francis
turbine
is
considered
a
reference
for
numerical
investigation
using
computational
dynamics
(CFD)
tool.
study
presented
an
evaluation
high
head
different
operating
conditions
sediment
concentrations.
modified
Grant
Tabakoff
model
used
rate
calculation.
To
investigate
effect
various
conditions,
conducted
at
part
load,
best
efficiency
point
(BEP)
load.
Also,
examine
impact
suspended
on
components,
solid
concentration
varies
from
500,
1200,
2000,
3000
4000
ppm.
observed
similar
all
stay
vane,
guide
vane
runner,
but
density
different.
higher
full
load
than
BEP
condition.
vanes
runner
highly
susceptible
absolute
velocity
relative
respectively.
variation
qualitatively
in-line
with
on-field
It
also
found
that
increase
almost
linear
more
90%
79%
Physics of Fluids,
Journal Year:
2023,
Volume and Issue:
35(3)
Published: Feb. 18, 2023
Cavitating
vortex
rope
at
part
load
(PL)
condition
lower
values
of
the
Thoma
number
(σ)
induces
severe
pressure
fluctuation
and
efficiency
reduction
in
a
Francis
turbine,
which
ultimately
hinders
continuous
energy
production.
Installation
fins
draft
tube
(DT)
can
mitigate
these
instabilities
safeguard
turbine
operation
with
maintenance
costs.
The
effect
on
hydraulic
performance
internal
flow
physics
PL
variation
σ
is
examined
present
numerical
investigation.
For
two
extreme
opposite
σ,
characteristics
are
predicted
accurately
for
without
by
conducting
transient
simulations
using
ANSYS-CFX.
findings
structured
unstructured
grid
points
validated
experimental
results.
turbine's
remains
constant
higher
numbers,
as
value
decreases,
declines.
cavitation
formation
inside
DT
mitigated
significantly
minimum
while
maximum
value,
bubble
generation
restricted.
Compared
to
fin
case,
swirl
intensity
minimized
remarkably
(68%)
presence
lowest
σ.
rate
manifested
fins,
about
60%
than
fins.
At
pulsations
induced
reduced
43%
finned
tube.
Therefore,
stable
production
maximized
installation
both
numbers.
Physics of Fluids,
Journal Year:
2024,
Volume and Issue:
36(3)
Published: March 1, 2024
Efficiency
and
grid
stability
can
be
improved
by
variable
speed
operation
using
doubly
fed
induction
machine
technology
for
pumped
storage
plants
experiencing
significant
head
variations.
With
the
higher
penetration
of
intermittent
renewable
energy
sources,
viz.,
solar
wind,
may
stabilized
operating
reversible
pump-turbines
(RPTs)
in
off-design
conditions.
In
a
turbine
mode,
RPT
is
more
susceptible
to
fatigue
vibrations
when
at
as
result
hydraulic
instability
generated
rotor–stator
interaction
(RSI);
therefore,
its
performance
becomes
even
critical.
The
powerhouse
structural
components,
including
floors
columns,
could
experience
intense
because
this
instability.
Therefore,
it
essential
investigate
RSI
RPTs
head.
These
investigations
present
results
numerical
analysis
associated
pressure
fluctuations
high-head
scaled
model
was
used,
simulations
were
executed
utilizing
shear
stress
transport
k-ω
turbulence
model.
performed
best
efficiency
point
conditions
having
optimized
rotational
speed.
show
that
main
source
all
RSI,
where
dominant
frequencies
are
blade
passing
frequency
(9fn)
harmonics.
It
also
found
lowers
RPT.
Energies,
Journal Year:
2023,
Volume and Issue:
16(13), P. 5131 - 5131
Published: July 3, 2023
This
review
addresses
the
current
state
of
research
into
active
control
and
suppression
vortex
rope
in
hydroturbines
under
off-design
operating
conditions.
Only
methods
that
can
be
“switched
on”
when
required
conditions
are
considered
this
work.
The
focuses
on
air
addition
flow,
as
well
various
auxiliary
fluid
jets.
It
includes
all
best
practices
for
numerical
experimental
studies.
inferred
from
a
modern
flow
system
should
comprehensive,
designed
specific
hydroturbine
geometry,
obtain
feedback
flow.
Injecting
~2%
impeller
fairing
cone
appears
optimal
suppressing
pressure
pulsations
without
significant
efficiency
loss.
cost
injection
is
rarely
estimated,
but
use
an
automatic
venting
minimize
overheads
potentially
improve
efficiencies
at
low
gas
contents.
Fluid
jets
ranging
3%
to
12%
main
rate
efficiently
suppress
pulsations,
their
high
energy
requirements
limit
use.
Azimuthal
perturbation
promising
it
does
not
require
loss,
practical
implementation
remains
challenging
one
needs
accurately
know
dynamics
capable
real-time
manipulation
Physics of Fluids,
Journal Year:
2023,
Volume and Issue:
35(6)
Published: June 1, 2023
The
part
load
operation
of
a
Francis
turbine
generally
develops
rotating
vortex
rope
(RVR)
in
the
draft
tube,
generating
flow
instabilities
and
pressure
pulsations.
present
work
reports
axial
water
injection
method
to
mitigate
RVR
its
associated
pulsations
tube.
runner
cone
is
modified
install
nozzle
three
different
designs
for
jet
injection.
Water
injected
axially
at
rate
0.5%
2%
main
flow.
Spectral
analysis
performed
assess
amplitude
dominating
frequency
affected
by
Spectrogram
spatial
harmonic
decomposition
show
reduction
synchronous
asynchronous
pulsation
amplitudes.
recovery
tube
also
improved.
spectral
shows
that
1%
1.25%
most
effective.
above
causes
near
bend
as
bounces
back
after
striking
elbow.
A
sharp
decrease
Strouhal
observed
efficiency
improved
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(2)
Published: Feb. 1, 2025
Hydropower
is
a
clean,
renewable,
and
highly
efficient
energy
source
accounts
for
about
16%
of
global
electricity
production.
Apart
from
baseload
generation,
hydraulic
turbines
are
more
often
subjected
to
less
off-design
operating
conditions
handle
the
fluctuating
demands
stabilize
power
grid.
These
sub-optimal
operations
result
in
flow
instabilities
such
as
vortex
breakdown
inter-blade
vortices,
which
reduce
overall
efficiency
produce
severe
pressure
pulsations.
This
review
summarizes
various
forms
theories
developed
explain
phenomena.
The
impact
these
on
turbine
operation
discussed.
Mathematical
models
describe
swirling
flows
downstream
Francis
runner
also
presented.
Parameters
that
influence
characteristics
outlined.
concludes
with
discussion
methods
alleviate
adverse
effects
turbines.
