Analysis of the Soot Particle Size Distribution in a Laminar Premixed Flame: A Hybrid Stochastic/Fixed-Sectional Approach
Résumé
The numerical simulation of the soot particle size distribution in flames is addressed by
solving the balance equations for total number density and the probability density function
of particle sizes, leading to a hybrid stochastic/fixed-sectional method for solving soot
population balance equation. Well established models are introduced in these equations for
the chemistry of PAH in ethylene combustion, for particle nucleation, growth, agglomeration
and oxidation. These closures are combined with a stochastic approach, which drives
the evolution of a fixed number of computational particles used to solve for the particle
size distribution with a control of agglomeration and numerical roundoff error through a
fixed sectional discretisation. A laminar sooting flame is simulated to compare the results
against measurements and previous numerical simulations, confirming the validity of the
novel approach in terms of accuracy and CPU efficiency. The relation between the mobility
diameter, measured in the experiments, and the equivalent sphere diameter, introduced
in the modeling, is discussed under this novel numerical framework. The influence of the
fractal particle shape on the simulated particle size distribution is explored. Finally, Particle
Size Distributions obtained from the hybrid method are compared to the ones obtained
with a representative fixed-sectional method.
Origine : Fichiers produits par l'(les) auteur(s)