This study describes tests with a fast clocked multispark ignition system intended to improve the stability of inflammation during charge stratification. The advantage of this ignition system is the capability it provides to adjust the number of sparks, the duration of single sparks and the intensity of the primary current. The basic engine test parameters were first set in an optically accessible pressure chamber under conditions approximating an engine. Two strategies were examined to analyze their effect on inflammation in stratified charge mode.
On the one hand, the multispark ignition (MSI) system allows implementing an intermittent spark sequence in the spark gap between the spark plug electrodes. On the other hand, precisely timed pulsing of spark energy into the plasma channel during charge motion can generate a very large deflection of the ignition spark. Both ignition strategies were analyzed in an indicated single cylinder engine's combustion chamber at different operating points to determine the respective tolerance limits of the engine operation and inflammation process.
The results demonstrate that the multispark ignition system may be employed to extend the range of ignition without misfire by a factor of up to five in stratified charge mode. Furthermore, electrical quantities were measured to compare the ignition energy of a multispark ignition system and a conventional ignition system.
In addition, the potentials for using the ignition voltage analysis as a method of measurement to determine local air/fuel ratios at the spark plug are highlighted. Being refined in this project, this method of measurement is based on the analysis of the disruptive voltage in different modes of operation and the thermodynamic conditions derived from the ignition point.
