Soot Quantification of Single-Hole Diesel Sprays by Means of Extinction Imaging

A radiation-based 2-color method (2C) and light extinction imaging (LEI) have been performed simultaneously to obtain twodimensional soot distribution information within a diesel spray flame. All the measurements were conducted in an optically accessible two-stroke engine equipped with a single-hole injector. The fuel used here is a blend of 30% Decane and 70% Hexadecane (in mass). According to previous research, operating conditions with three different flame soot amounts were investigated. The main purpose of this work is to evaluate the two soot diagnostics techniques, after proper conversion of soot-related values from both methods. All the KL extinction values are lower than the saturation limit. As expected, both techniques show sensitivity with the parametric variation. The soot amount increases with higher ambient gas temperature and lower injection pressure. However, the LEI technique presents more sensitivity to the soot quantity. Differences in the KL value on the spray axis between LEI and 2C increase with higher soot quantity.