Journal of Aerosol Science,
Journal Year:
2024,
Volume and Issue:
179, P. 106385 - 106385
Published: April 21, 2024
Determining
the
soot
volume
fraction
(fv)
in
combustion
environments
requires
detailed
knowledge
of
optical
properties
particles,
and
particular
their
absorption
function
E(m).
This
study
addresses
a
fundamental
lack
information
on
2-4
nm
particles.
Recent
works
based
modeling
photoelectron
emission
yields
UV-vis-NIR-absorption
measurements
found
sharp
decrease
E(m)
with
particle
size
vis-NIR
spectral
region,
which
is
inconsistent
situ
detection
particles
near-infrared
region
by
laser-induced
incandescence
(LII)
or
sensitive
methods
like
cavity
ring-down
extinction
(CRDE).
The
objective
this
twofold:
first,
an
original
method
for
determination
including
proposed.
Then,
dynamic
two
widespread
diagnostics,
LII
CRDE,
are
compared
over
three
orders
magnitude
fv
atmospheric
premixed
ethylene/air
flames
different
flow
rates
C/O.
absolute
value
its
variation
derived
from
analysis,
does
not
require
complex
modeling.
analysis
comparison
between
experimental
calculated
LII/LIImax
signals
low
fluence
regime,
LIImax
being
plateau
curve,
reached
at
larger
than
1
J/cm2
smallest
to
vary
0.15
C/O
up
0.36
richest
flames.
Concerning
dynamics
excellent
agreement
above
threshold
(C/O)limit,
while
exhibits
stronger
below
(C/O)limit.
discrepancy
attributed
dependence
negligible
but
increases
when
decreases
distribution
(PSD),
measured
scanning
mobility
sizing,
reveals
monomodal
bimodal
PSDs
having
diameter
range
2.3-7.5
depending
flame
conditions.
It
suggested
that
contained
first
PSD
mode,
dominant
range,
could
be
affected
significant
second
mode.
Energies,
Journal Year:
2024,
Volume and Issue:
17(16), P. 3866 - 3866
Published: Aug. 6, 2024
In
studying
the
effects
of
oxygen
concentration
and
molecular
structure
on
morphologies
soot
particles
produced
by
hydrocarbon
fuels,
ethylene
ethane
were
chosen
as
experimental
fuels.
With
a
Gülde
laminar
coaxial
diffusion
flame
device,
particle
device
was
used
to
sample
at
different
concentrations
(21%,
24%,
26%,
28%,
31%)
heights
above
burner
(HABs
=
10
mm,
20
30
40
50
mm).
High-resolution
transmission
electron
microscopy
(HRTEM)
scrutinize
analyze
varying
concentrations.
The
findings
suggest
that
same
concentration,
produces
brighter
taller
flames.
an
increase
in
flames
gradually
decrease
height
become
brighter.
HAB,
average
primary
diameter
(Dp)
increases
initially
then
decreases,
fractal
dimension
(Df)
increases,
aggregates
transition
from
strips
chains
clusters.
At
(HAB
mm),
Dp
Df
carbon
layer
torsion
resistance
(Tf)
spacing
(Ds)
increase,
changes
parallel
arrangement
curved
form
denser
network
aggregations.
Fuel,
Journal Year:
2023,
Volume and Issue:
361, P. 130613 - 130613
Published: Dec. 21, 2023
It
is
shown
that
signals
from
both
laser-induced
incandescence
(LII)
of
soot
and
fluorescence
(LIF)
polycyclic
aromatic
hydrocarbons
(PAHs)
decrease
with
hydrogen
addition
(in
volume
fractions
3%,
6%
9%
respect
to
the
fuel
mixture)
ethylene–air
inverse
diffusion
flames
(IDFs).
The
structure
IDF
suppresses
oxidation
effect
under
these
conditions
has
been
studied.
Experiments
were
performed
using
a
frequency-doubled,
pulsed
dye
laser
perform
planar
LIF
PAH,
fibre
LII.
In
relative
terms,
LII
signal
decreases
more
sharply
than
PAH
signal.
This
would
be
consistent
dependence
inception
on
concentration
as
well
suppression
growth
via
reduced
perhaps
other
precursors
such
acetylene.
Similar
trends
in
are
observed
at
range
heights
above
burner,
despite
measurement
locations
encompassing
wide
absolute
levels.
As
comparison,
influence
adding
methane
same
was
also
studied
found
suppress
but
far
lesser
extent
case
hydrogen.
