Fractal and Projected Structure Properties of Soot Aggregates.
Fractal and Projected Structure Properties of Soot
Aggregates.
(1326 K)
Koylu, U. O.; Faeth, G. M.; Farias, T. L.; Carvalho, M.
G.
Combustion and Flame, Vol. 100, No. 4, 621-633, March
1995.
Sponsor:
Naval Research Laboratory, Washington, DC
Keywords:
soot; aggregates; fractal properties; fractals; fractal
properties; simulation; turbulent flames; laminar
flames; equations; soot aggregates
Abstract:
The structure of soot aggregates was investigated,
emphasizing the fractal properties as well as the
relationships between the properties of actual and
projected soot images. This information was developed
by considering numerically simulated soot aggregates
based on cluster-cluster aggregation as well as measured
soot aggregates based on thermophoretic sampling and
analysis by transmission electron microscopy (TEM) of
soot for a variety of fuels (acetylene, propylene,
ethylene, and propane) and both laminar and turbulent
diffusion flame conditions. It was found that soot
aggregate fractal properties are relatively independent
of fuel type and flame condition, yielding a fractal
dimension of 1.82 and a fractal prefactor of 8.5, with
experimental uncertainities (95% confidence) of 0.08 and
0.5, respectively. Relationships between the actual and
projected structure properties of soot, e.g., between
the number of primary particles and the projected area
and between the radius of gyration of an aggregate and
its projected image, also are relatively independent of
fuel type and flame condition.
