A New Reduced Chemical Kinetic Model of N-Heptane Combustion for HCCI Engine Simulations

The paper presented a new reduced chemical kinetic model for the Homogeneous Charge Compression Ignition(HCCI)combustion when using n-heptane as the fuel,This model consists of 44 species and 72 reactions.The reduced model includes four sub-models,in which the sub-model for low temperature reaction was established by determining particular aldehydes and small hydrocarbons in the Li-model,the sub-model for large molecules decomposing directly to small molecules was developed for linking the low-temperature reaction to the high-temperature reaction,the sub-model for high-temperature reaction was given through some modifications to Griffiths-model such as eliminating several reactions and adding two oxidization reactions of CO and CH_3O,the sub-model for NO_x formation from the Golovitchev reduced kinetic model was introduced into the reduced model.This reduced model could simulate the cool-flame and hot-flame combustion process of n-heptane as well as NO_x formation in HCCI engines,and the calculation results also agreed well with those from the detailed model.The computational time by using the reduced model is 1/1 000 to that using the detailed model.HCCI engine simulations using chemical reaction with CFD are attainable by using this reduced model.