In this paper, we aim to develop a comprehensive ignition model for three dimensional (3D) computational fluid dynamics (CFD) combustion modeling in Spark-Ignited (SI) engines. In the proposed model we consider the following aspects separately to model the complex spark ignition process. An electrical circuit is solved for calculation of the energy transferred to the spark plasma channel. The spark itself is represented by computational particles for monitoring its motion and ignitability. Heat diffusion from the spark toward the surrounding mixture is calculated with a one dimensional (1D) model, resulting in the temperature obtained at the surface of the spark channel. Based on the calculated temperature and interpolated pressure and local mixture composition, an instantaneous ignition delay time is read from tabulated values for every particle representing the spark channel. The final ignitability criterion is defined by a precursor calculated with a zero dimensional (0D) model, which accounts for the history of changes in spark surface temperature and local mixture properties. As soon as the precursor reaches a threshold value for a given spark channel particle, a flame kernel is introduced at a position of the particle. Flame propagation is generally treated by the G-equation combustion model. Validation is performed by measuring the spark discharge process in high velocity flow field and single cylinder AVL research engines. We demonstrate that the proposed model can correctly reproduce the electrical circuit, spark channel dynamics and overall engine performance.

This content is only available via PDF.

Article PDF first page preview

Article PDF first page preview
You do not currently have access to this content.