Flame structure transition and instability excitation by pilot fuel in a centrally staged combustor
Physics of Fluids,
Год журнала:
2025,
Номер
37(1)
Опубликована: Янв. 1, 2025
The
pilot
stage
plays
a
crucial
role
in
central-staged
combustion
technology.
This
study
aimed
to
investigate
the
impact
of
jet-type
on
flame
structure
and
instability
novel
strong
coupled
centrally
staged
swirl
gas
turbine
combustor,
using
both
experiments
large
eddy
simulations
(LES).
Nonlinear
dynamic
analyses
pressure,
including
phase
recurrence
plots,
were
performed
alongside
proper
orthogonal
decomposition
structures.
It
is
indicated
that
richer
worsens
system.
An
increase
equivalence
ratio
leads
enhanced
non-premixed
downstream
shift
heat
release
region.
transition
results
shape
from
an
attached
V-shaped
intermittent
lifting
U-shaped
flame.
surface
statistics
LES
strain
rate
progress
variable
gradient
lean
rich
conditions
compared.
Under
conditions,
demonstrates
increased
sensitivity
flow
field
fluctuations,
intensifying
vortex–flame
interactions.
interaction
causes
large-scale
stretching
even
extinction
flame,
exacerbating
observed
this
study.
These
insights
offer
deeper
understanding
multi-staged
central
systems.
Язык: Английский
The excitation and evolution characteristics thermoacoustic instability in syngas micromixed combustion
Physics of Fluids,
Год журнала:
2025,
Номер
37(2)
Опубликована: Фев. 1, 2025
This
paper
presents
an
experimental
study
of
thermoacoustic
oscillations
synthetic
gas
(syngas)
micromixed
combustion,
in
which
the
excitation
and
evolution
characteristics
were
obtained
as
a
function
flame
equivalence
ratio.
The
results
show
that
initiates
when
ratio
drops
below
0.80,
with
undergoing
mode
transferring
decreases.
When
is
0.70,
second-order
oscillation
begins
to
dominate.
At
0.50,
(640
Hz)
dominate
first-order
(320
Hz).
Flame
flashback
coexists
starting
at
0.5,
where
chemiluminescence
distribution
indicates
heat
release
rate
pulsation
maximal
burner
outlet,
other
radicals
vary
Low
promotes
generation
amino
group
radicals,
thereby
interfering
production
nitrogen
oxides.
shape
also
depends
on
initially
conical
flattens
innovation
this
lies
its
first
exploration
syngas
contributes
formulation
design
criteria
for
burners.
These
clarify
combustion
facilitates
prediction
control
or
oscillations.
Язык: Английский