New Aspects on Spark Ignition

Fundamental investigations have been made on processes in common spark plugs useful for ignition of fuel-air-mixtures. Development of spark discharge from the early beginnings as well as the initiation of chemical reaction have been studied experimentally by using very high frequency measuring technique, radiation measurements, spectroscopic methods and interferometry by a nitrogen laser (∼300 ps). The measurements have been carried out in non-reacting gases (N₂, air) as well as in inflammable mixtures. A complete description will be given of the total process from the spark breakdown to the arc and glow-phase, resp., in the millisecondrange including temperature, local dimensions, energy distribution and radicals which can be formed.