On Simulation of the Inflammation Period in Spark Ignition Engines

ABSTRACT

A simulation model has been evolved which performs the duration of the inflammation period t_EP. The principal parameters of this model are environmental condition, air supply, mixture composition with including residual gas. and engine speed. Due to the intention of the model to be a design tool rather than a precise but complicated model for fundamental research the algorithms used are fast and according to physical properties. These algorithms have been fitted to experimental results obtained by a spark ignition engine. The prediction of t_EP at reference conditions has been formulated based on combination of mixture density at a particular crankangle and the ratio of integral length scale and turbulence intensity at ignition time. Deviation flame speed relations. The influence of engine speed has been assumed to result in changed turbulence intensity which influences t_EP. The in mixture composition from reference conditions has been performed by laminar performance of the model is good, on most conditions the difference between predicted and analyzed value of t_EP is better than 4 deg CA

Key Words:

• spark ignition engine
• energy conversion
• ignition delay inflammation period
• exhaust emission
• simulation model