A Numerical Simulation of Soot Formation in Spray Flames

Abstract

A two-dimensional numerical simulation is applied to spray flames formed in a laminar counterflow, and soot formation behavior is studied in terms of equivalence ratio and radiation in detail. N-decane (C10H22) is used as a liquid spray fuel, and the droplet motion is calculated by the Lagrangian method. A one-step global reaction is employed for the combustion reaction model. A kinetically based soot model with flamelet model is employed to predict soot formation. Radiation is taken into account using the discrete ordinate method. The results show that the soot is formed in the spray diffusion flame region and its radiation emission increases with increasing the equivalence ratio of the droplet fuel. This trend is in good agreement with that of the luminous flame behavior observed in the experiment. The radiation is found to strongly affect the soot formation behavior. Without the radiation model, the soot volume fraction is fatally overpredicted.