Computational Study of the Absorption and Scattering Properties of Soot.
Computational Study of the Absorption and Scattering
Properties of Soot.
Farias, T. L.; Carvalho, M. G.; Koylu, U. O.; Faeth, G.
Combustion Institute/Eastern States Section. Chemical
and Physical Processes in Combustion. Technical
Meeting, 1993. October 25-27, 1993, Princeton, NJ,
394-397 pp, 1993.
Sponsor:National Institute of Standards and Technology,
combustion; soot; absorption; scattering coefficient;
simulation; aggregates; soot aggregates
Soot is present within most nonpremixed
hydrocarbon-fueled flames, which affects their
structure, radiation and pollutant emission properties.
Thus, the absorption and scattering properties of soot
are of interest in order to estimate continuum radiation
from soot and to interpret nonintrusive optical
measurements of soot concentrations and structure. Soot
optical properties are challenging, however, dut to the
complexity of soot structure. For example, while soot
consists of small primary particles that individually
satisfy the small particle (Rayleigh) scattering
approximation, these particles form branched aggregates
that exhibit neither Rayleigh nor Mie scattering
behavior. Nevertheless, a potentially useful
approximate theory of soot optical properties (denoted
RDG-FA theory in the following) has been developed
recently, based on the Rayleigh-Debye-Gans (RDG)
scattering approximation while assuming that soot
aggregates are mass-fractal objects. Past theoretical
and experimental evaluations of RDG-GA theory, however,
have not been definitive due to computational and
experimental limitations. Thus, the objective of the
present investigation was to complete an additional
theoretical evaluation of RDG-FA theory for soot, based
on computations using more exact theory for populations
of mass-fractal aggregates having prescribed properties.