Experimental and kinetic modeling study of laminar premixed decalin flames

Abstract

Laminar premixed flames of decalin with equivalence ratios of 0.75, 1.0 and 1.8 were studied using synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). Dozens of flame species were identified and their mole fraction profiles were evaluated, including a series of free radicals. A detailed kinetic model of decalin combustion consisting of 538 species and 3218 reactions was developed and validated on the new flame data. The rate of production analysis at different equivalence ratios were performed to help understand the kinetics in the decompostion of decalin and the formation of some key intermediates. The H-atom abstraction reactions play an overwhelming role in the primary decomposition of decalin at flame conditions. Monocyclic aromatic hydrocarbons (MAHs) are mainly produced from the decomposition of decalin, while polycyclic aromatic hydrocarbons (PAHs) originate from mass growth process of PAH precursors. In addition, some oxygenated intermediates have important contributions to the formation of key MAHs and PAHs such as benzene (A1) and indene (C9H8). The direct production of PAH precursors in fuel decomposition process explains the higher sooting tendency of decalin than n-alkanes and benzene. Furthermore, the model was used to simulate literature data of decalin combustion, such as species profiles in jet stirred reactor oxidation of decalin and ignition delay times of decalin.