Assessment of Electric Arc Models used in Recent Spark Ignition Models

Recent comprehensive spark ignition models for CFD simulation of automotive gasoline engines take into account the behaviour of an electric arc under local flows at the spark plug. Inherent assumptions of these models are discussed, in particular, the assumption that the arc passively follows the flow. Simulation results are compared to test bed results. A relative velocity between arc and flow is identified and based on physical grounds a modification of the arc modelling is presented. The influence of pressure and electrode gap is discussed with emphasis of possible applications of such models for large stationary gas engines.