Numerical Study Of RCCI Combustion And Influence Factor Analysis Using Detailed Chemical Kinetics

Reactivity Controlled Compression Ignition(RCCI)combustion,a new type of low temperature combustion concept,has attracted worldwide attention due to its ultra-low pollutants and high thermal efficiency.RCCI combustion process and the influential factors of combustion has been studied in this thesis.To study fuel reactivity controlled combustion process,a quasi-dimensional multi-zone RCCI combustion model has been development,which allows to simulate the combustion process with detailed reaction mechanism.And the influence of gasoline to diesel ratio and diesel injection timing has been studied.To further consider the flow and the injection effect,a three-dimensional combustion model is used.The 3-dimenstional study is validated and calibrated with experimental data,the effects of gasoline to diesel ratio,inlet temperature,inlet pressure,diesel percentage of the first injection,and engine speed has been studied.The results show that the ratio of gasoline to diesel can significantly influence combustion process and stability.Boosting pressure can increase the engine output power,decrease the CO and unburned hydrocarbon(UHC)emission,while lead to an increase in NOx emission.An inlet heating enhances the peak pressure and NOx emission,while reducing the inlet temperature increases the soot emission.Increasing the amount of the first injected diesel can postpone ignition timing.Engine speed also plays an important role on the UHC emission associated with combustion incompletability.