| Résumé | Ignition timing control is crucial for compression ignition (CI) engines. Modelling ignition phenomenon is essential for design and operation of CI engines. Accurate prediction of ignition phenomenon requires a robust ignition model. Therefore, detailed and semi-detailed chemical kinetics have been developed for various fuels, such as [1-3]. These kinds of kinetics models are able to reasonably predict ignition performance in engines. However, detailed or semi-detailed kinetics models usually include many species and reactions. The use of these kinds of detailed or semi-detailed models in the prediction of ignition and combustion process in engines is still too computationally expensive today. Therefore, reduced or simplified kinetics models that include limited number of species and are capable of reasonably describing ignition and combustion performance in engines are still important. Given the fact that simplified one- or two-step models usually cannot reasonably describe the main features of ignition process, especially for those fuels with two stage combustion processes, such as diesel fuels, reduced kinetic model is a more appropriate choice for the prediction of ignition process in practical applications. The so-called Shell ignition model developed in 1970s [4,5] is a reduced thermo-kinetic model that includes limited species and is capable of reasonably predicting ignition process in engines, provided that appropriate rate expressions are provided. This study focuses on the practical application of the Shell model to predict the ignition of various renewable fuels in homogeneous charge compression ignition (HCCI) engines. The rate expressions of the Shell model will be obtained by an optimization scheme based on the ignition delay data obtained from Ignition Quality Tester (IQT). |
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