Abstract

There is renewed interest in understanding the detailed structure and optical properties of soot because it is the second largest contributor (after CO2 ) to radiative forcing. In addition, the soot contribution exhibits by far the largest uncertainty of them. Furthermore, such understanding continues to be sought for accurate monitoring of soot emissions, carbon black synthesis and fire detection. Here, this understanding is advanced by discrete element modeling (DEM) of soot surface growth, agglomeration and oxidation along with rigorous comparison to experimental data at various combustion conditions from different laboratories. The DEM -derived agglomerates are coupled with the discrete dipole approximation (DDA) to account for soot morphology and maturity revealing the evolution of its light absorption and scattering during combustion in premixed flames. The DEM -DDA can be readily used for optimizing the selectivity of fire detectors and advancing soot optical diagnostics, as well as for a more accurate estimation of the climate impact of soot.