Detailed modeling of soot formation in laminar premixed ethylene flames at a pressure of 10 bar

Abstract

Detailed modeling of soot particle nucleation, growth and oxidation in laminar premixed ethylene-air flames at a pressure of 10 bar is presented. The employed kinetic model of soot formation, developed and tested earlier for subatmospheric and atmospheric flames, can quantitatively describe the experimental soot volume fraction profiles collected in a number of ehtylene flames at high pressures. The kinetic model consists of initial aromatic ring formation from nonaromatic species, planar polycyclic aromatic hydrocarbon (PAH) growth through the hydrogen-abstraction-acetylene-addition reaction mechanism, particle nucleation through coalescence of PAHs, particle growth by coagulation and surface reactions of the forming clusters and particles, and particle oxidation. Analysis of the computational results obtained at 10 bar and additional tests performed for a 1-bar flame suggest that the influence of pressure on soot production arises mainly from the larger concentration of acetylene, which affects both the soot surface growth and the nucleation of soot particles.