Energy & Fuels, Vol.32, No.9, 9949-9960, 2018
A Simplified Mechanistic Model of Three-Component Surrogate Fuels for RP-3 Aviation Kerosene
In this study, a detailed chemical reaction kinetic model of a three-component surrogate fuel (73% n-dodecane, 14.7% 1,3,5-3-trimethylcyclohexane, and 12.3% n-propylbenzene) for RP-3 aviation kerosene was simplified, and a simplified mechanism for this fuel was obtained and validated. The detailed chemical reaction kinetic model included 257 components and 874 elementary reactions. In the first step, a mechanism consisting of 109 components and 423 elementary reactions was constructed from the detailed model using a directed relation graph (DRG). The second step, based on the first, was to construct an 84-component, 271-elementary-reaction mechanism using a DRG based on error propagation (DRGEP) and computational singular perturbation (CSP). In the third step, path analysis was applied to analyze the combustion paths under atmospheric pressure and high-temperature conditions; the results were compared with those of the detailed mechanism and the simplified mechanism of the second step to remove unimportant reaction paths or to supplement important paths that were reduced in the first two steps. In the final step, a simplified mechanism of the three-component surrogate fuel suitable for high temperature and atmospheric pressure was obtained, which involved 59 components and 158 elementary reactions. Test data of the ignition delay time and the laminar flame velocity of RP-3 kerosene were used to verify the simplified mechanism for the three-component surrogate fuel. The results showed that the numerical results for the proposed simplified mechanism were consistent with the test data. Finally, to verify the engineering practicality of the simplified mechanism proposed in this study, taking a Bunsen burner as the physical model, a premixed pre-evaporation combustion flame was numerically simulated by using the simplified mechanism for the three-component surrogate fuel. The numerical calculation results of the simplified mechanism were consistent with the test data, and the computation time was within the acceptable range of the engineering application. Therefore, the simplified mechanism for the three-component surrogate fuel can be used for numerical simulation of engineering combustion with kerosene fuel.