A new skeletal mechanism for diesel-n-butanol blends combustion in engine. (15th March 2020) - Li, Yuqiang
Abstract: A new skeletal mechanism consisting of 116 species and 433 reactions for diesel-n-butanol blends combustion in engine is proposed in this study. Starting from a detailed chemical kinetics considering high-temperature and low-temperature reaction pathways of n-butanol, a reduced reaction mechanism was built using directed relation graph with error propagation and sensitivity analysis (DRGEPSA), computational singular perturbation (CSP) and reaction pathway analysis (RPA) methods. Then, it was further combined with a reduced diesel surrogate fuel chemical reaction mechanism of n-heptane/toluene with the NOx and soot formation kinetics embedded. After optimizing the reaction rate constants of selected reactions in the coupled mechanism based on sensitivity analysis, the final n-heptane/toluene-n-butanol skeletal mechanism for diesel-n-butanol blend oxidation was generated and validated against ignition delay time, laminar flame speed and premixed flame species profiles, and a good prediction was presented. In addition, the current mechanism was coupled into the KIVA3V2-CANTERA to simulate the combustion and emissions characteristics of an engine fueled with B00, B20 and B40 (0 vol%, 20 vol% and 40 vol% n-butanol blended with diesel). It is indicated that the in-cylinder pressure, heat release rate and NOx and soot emission of diesel/n-butanol blend can be well reproduced by the newly developed skeletal mechanism with a reliable accuracy.