TY - JOUR
T1 - Determining fractal properties of soot aggregates and primary particle size distribution in counterflow flames up to 10 atm
AU - Amin, Hafiz M.F.
AU - Bennett, Anthony
AU - Roberts, William L.
PY - 2019
Y1 - 2019
N2 - Experimental investigations of soot morphology are performed in counterflow flames of N2-diluted ethylene and air, up to 10 atm. A thermophoretic sampling device is attached to a pressure vessel containing a counterflow burner where flames with an ethylene mole fraction
of 0.3 are stabilized at 3, 5, and 6 atm. To allow measurements at
higher pressures, the fuel mole fraction is lowered to 0.2 to reduce the
soot loading and flames are studied at 5, 7, and 10 atm. Thermophoretic
sampling of the soot zone is performed using TEM grids. The sampling
process causes minimal flame disturbances. Soot collected on TEM grids
is analyzed under transmission electron microscope
(TEM). Primary particle size distributions are inferred at each
pressure by manually analyzing the primary particles from TEM images.
Fractal properties of soot at each pressure are also obtained by
analyzing the TEM images at comparatively low magnifications. Mean
primary particle diameter increases from 17.5 to 47.1 nm as the pressure
is increased from 3 to 10 atm, whereas the fractal dimension
and prefactor do not change with pressure up to 10 atm. For the flames
studied here, fractal dimension lies between 1.61 and 1.67 whereas
fractal prefactor varies between 1.68 and 1.86 without following any
apparent trend with pressure.
AB - Experimental investigations of soot morphology are performed in counterflow flames of N2-diluted ethylene and air, up to 10 atm. A thermophoretic sampling device is attached to a pressure vessel containing a counterflow burner where flames with an ethylene mole fraction
of 0.3 are stabilized at 3, 5, and 6 atm. To allow measurements at
higher pressures, the fuel mole fraction is lowered to 0.2 to reduce the
soot loading and flames are studied at 5, 7, and 10 atm. Thermophoretic
sampling of the soot zone is performed using TEM grids. The sampling
process causes minimal flame disturbances. Soot collected on TEM grids
is analyzed under transmission electron microscope
(TEM). Primary particle size distributions are inferred at each
pressure by manually analyzing the primary particles from TEM images.
Fractal properties of soot at each pressure are also obtained by
analyzing the TEM images at comparatively low magnifications. Mean
primary particle diameter increases from 17.5 to 47.1 nm as the pressure
is increased from 3 to 10 atm, whereas the fractal dimension
and prefactor do not change with pressure up to 10 atm. For the flames
studied here, fractal dimension lies between 1.61 and 1.67 whereas
fractal prefactor varies between 1.68 and 1.86 without following any
apparent trend with pressure.
UR - http://www.scopus.com/inward/record.url?scp=85053073836&partnerID=8YFLogxK
U2 - 10.1016/j.proci.2018.07.057
DO - 10.1016/j.proci.2018.07.057
M3 - Article
AN - SCOPUS:85053073836
SN - 1540-7489
VL - 37
SP - 1161
EP - 1168
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
IS - 1
ER -