In the realm of engines, I always thought of combustion as an exothermic reaction that could only be ignited by a source of heat. The heat of compression in the case of a diesel and obviously a spark in a Spark Ignition engine. I recently had the pleasure of viewing a personal presentation and demonstration of a new ignition system that, if I understood correctly, ignited air/fuel with free radicals produced through the creation of cold plasma instead of a spark. Among other claimed benefits, the one that caught my attention was the claim of a considerable faster charge burn rate.
I don't quite 100% understand "free radicals" and their role in combustion. Anyone have some insight on this? Shan?