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ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Modeling Spark Ignition and Partially Premixed Flame Propagation in DISI Engines

Get access (open in a dialog) DOI: 10.1615/IHTC12.5050
6 pages

Resumo

A new model for spark ignition and partially premixed flame propagation in direct injection spark ignition (DISI) engines is developed and implemented into an enhanced KIVA-3V code. Based on the general idea of the discrete particle ignition kernel model by Fan et al. (1999) the ignition kernel developing after spark onset is represented by Lagrangian marker particles. However, in this new model the propagation of the premixed flame front of the so-called triple flame is estimated by marker particles as well, even after the end of the spark timing. Moreover, the effect of the supplied spark energy on the flame kernel development and the interaction of the turbulent flow field with the self-sustained flame front is modeled in detail. The diffusion part of combustion that can take place behind the premixed flame front in case lean and rich residuals mix because of turbulence is described by a an adjusted version of the characteristic time scale combustion model known from diesel engine modeling. The different submodels for flame kernel development, premixed flame front propagation and diffusion combustion are validated separately by comparison to experimental data. The results show that the model is capable of describing a partially premixed triple flame structure and that there is a generally good agreement with experimental data. The model is then applied to calculate combustion in a small DISC (direct injection stratified charge) two-stroke engine. Again, good accordance with experimental data can be achieved.