This paper presents an analysis of several equations used to model laser-induced incandescence (LII) of soot. The analysis
focuses on sub-models of the change in particle enthalpy during sublimation, conduction, and oxidation. Assuming that pressure
is constant, expressing the conductive cooling rate in terms of enthalpy instead of energy, thereby accounting for expansion
work, increases the signal decay rate and has an effect comparable to increasing the thermal accommodation coefficient from
0.30 to 0.38. Accounting for oxidative heating decreases the signal decay rate and has an effect comparable to decreasing
the accommodation coefficient from 0.30 to 0.25. As an estimate of magnitude of these effects, primary particle sizes inferred
from signal decay rates measured at low fluences may be over-predicted by as much as 17% if oxidation is neglected in the
model at O
2 partial pressures of ∼0.2 bar, under-predicted by 24% if expansion work is neglected, and under-predicted by only 9% if both
are neglected. This paper also provides updated parameterizations for average enthalpies of formation, molecular weights,
and total pressures of sublimed carbon clusters for use in LII models.
PACS 65.80.+n - 78.20.Nv - 42.62.-b - 44.05.+e