Insights into the Effects of Mechanism Reduction on the Performance of n-Decane and Its Ability to Act as a Single-Component Surrogate for Jet Fuels

Abstract

In this study, a detailed chemical reaction mechanism of n-decane containing 1034 species and 4268 reactions has been reduced at three different reduction levels to study the effects of subsequent mechanism reductions on the performance of n-decane. The detailed and reduced mechanisms were then used to validate ignition delays, laminar flame speeds, flame species, and species in a jet-stirred reactor. The one-half reduced mechanism performed nearly the same as the detailed mechanism in most of the cases. The one-fourth and one-eighth reduced mechanisms performed fairly well as compared to the detailed mechanism in some cases. The differences were further elaborated by sensitivity analyses of ignition delays and laminar flame speeds at different conditions followed by reaction pathway analysis of the detailed and one-eighth reduced mechanisms. These analyses indicated the absence or presence of certain reaction classes in reduced mechanisms that shaped the particular behavior of the mechanisms. To evaluate the capability of n-decane as a single-component surrogate for jet fuels, the experimental data of real-life jet fuels were used to validate the ignition delays and laminar flame speeds using the reaction mechanisms. Among all of the tested fuels, the ignition delay of jet A was reproduced fairly well by the detailed mechanism followed by jet S8 and jet RP-3 fuels with a noticeable discrepancy in the negative temperature coefficient (NTC) region. The one-eight reduced mechanism performed well in the NTC region. The laminar flame speeds of jet A and jet S8 fuels were predicted quite well by the detailed mechanism with the one-fourth reduced mechanism performing well at fuel-lean conditions. This strengthened the capability of n-decane as a single-component surrogate for jet fuels.