Sooting tendencies of diesel and jet fuel surrogate components

摘要

A necessary but challenging endeavor in combustion is developing diesel and jet fuel surrogates that mimic essential target fuel characteristics such as their sooting tendency and volatility. This is in part due to the scarcity of experimental sooting data for potential surrogate compounds in the appropriate high molecular weight range. To address this, in this work we provide quantitative sooting data for 12 diesel surrogate compounds, 13 jet fuel surrogate compounds, 2 reference diesel fuels, 1 aviation jet fuel, and 4 surrogate diesel fuels synthesized by blending surrogate compounds. Specifically, we have measured spatially resolved two-dimensional soot volume fraction distributions when these compounds are doped separately into the fuel stream of a methane/air coflowing flame (dopant mass fraction 0.5%). Color-ratio pyrometry was used to measure soot temperature and soot volume fraction (f_v) distributions. Yield sooting indices (YSI) were determined from the 2d f_v distributions as a quantitative measure of sooting tendency for all surrogate compounds and fuels. The sooting tendencies ranged from YSI = 7 (for n-decane) to YSI = 471 (for 1-methylnapthalene) on a scale where n-hexane and benzene have YSI values 0 and 100 respectively. The sooting tendencies of the diesel surrogate fuels were found to be very similar to the sooting tendency of the two reference diesel fuels. These data are expected to be useful in the formulation of surrogates with greater fidelity to the volatility and sooting characteristics of real fuels, and in validation of numerical soot models involving such surrogates.