TY - JOUR
T1 - Morphology of soot sampled from N2-diluted methane/air counterflow flames at elevated pressures via TEM imaging
AU - Amin, Hafiz M.F.
AU - Bennett, Anthony
AU - Roberts, William L.
PY - 2020/6/30
Y1 - 2020/6/30
N2 - An experimental work is carried out to investigate the influence of
pressure on morphological parameters of soot in counterflow flames of N2-diluted methane and air. Flames are stabilized at 3, 5, 7 and 10 atm in a pressure vessel and a global strain rate of 30 s−1
is maintained at all pressures by adjusting the inlet mass flux. The
mole fraction of methane is maintained at 0.7. The entire soot zone of
the counterflow flames are sampled using a thermophoretic sampling
device attached to the pressure vessel. Our sampling method minimizes
the flow disturbances to a level that they are visually negligible
during the sampling process. Collected samples are analyzed under a
transmission electron microscope and information about mean primary
particle diameter, fractal dimension (Df), fractal prefactor (kf)
and aggregate size distribution is inferred at different pressures. To
investigate the effects of carbon flux on primary particle size, fuel
mole fraction is decreased to 0.5 and primary particle size is
investigated at 5, 7 and 10 atm. Mean primary particle size increases by
70% when pressure is changed from 5 to 10 atm and remains independent
of fuel mole fractions. Geometric mean and geometric width of aggregate
size distributions also increase by increasing the pressure. Fractal
properties of soot aggregates are found to be insensitive to the
pressure. Fractal dimension varies between 1.56 and 1.65 while fractal
prefactor values range between 1.96 and 2.1.
AB - An experimental work is carried out to investigate the influence of
pressure on morphological parameters of soot in counterflow flames of N2-diluted methane and air. Flames are stabilized at 3, 5, 7 and 10 atm in a pressure vessel and a global strain rate of 30 s−1
is maintained at all pressures by adjusting the inlet mass flux. The
mole fraction of methane is maintained at 0.7. The entire soot zone of
the counterflow flames are sampled using a thermophoretic sampling
device attached to the pressure vessel. Our sampling method minimizes
the flow disturbances to a level that they are visually negligible
during the sampling process. Collected samples are analyzed under a
transmission electron microscope and information about mean primary
particle diameter, fractal dimension (Df), fractal prefactor (kf)
and aggregate size distribution is inferred at different pressures. To
investigate the effects of carbon flux on primary particle size, fuel
mole fraction is decreased to 0.5 and primary particle size is
investigated at 5, 7 and 10 atm. Mean primary particle size increases by
70% when pressure is changed from 5 to 10 atm and remains independent
of fuel mole fractions. Geometric mean and geometric width of aggregate
size distributions also increase by increasing the pressure. Fractal
properties of soot aggregates are found to be insensitive to the
pressure. Fractal dimension varies between 1.56 and 1.65 while fractal
prefactor values range between 1.96 and 2.1.
UR - http://www.scopus.com/inward/record.url?scp=85081010205&partnerID=8YFLogxK
U2 - 10.1016/j.combustflame.2020.02.017
DO - 10.1016/j.combustflame.2020.02.017
M3 - Article
AN - SCOPUS:85081010205
SN - 0010-2180
VL - 216
SP - 92
EP - 99
JO - Combustion and Flame
JF - Combustion and Flame
ER -