This study deveroped an innovative microwaye plasma combustion system to improve fuel economy and achieve higher efficiency for spark ignition (SI) engines. Microwave plasma technology was combined with an active ignition system, which generates plasma by applying a high-frequency voltage to the standard spark discharge. A standard ignition coil was used. The high-frequency voltage was research of plasma-assisted combustion hasCopyright @ 2012 by the Japan Society of Mechanical Engineers

We aimed at the development of the powerfu1 ignition system (active ignition) that achieves highly effective combustion.In order to achieve the stabilization of the initial combustion, we had been studying the generation of active species mass, yolumetric ignitien and a long pulse duration discharge. In this study, we developed the ignition system without a large-scale structural change from a conventional engine. The active ignition system consists ofa primary coil (ignition coil) ofstandard spark discharge, and a secondary coil ofhigh frequency supply. Plasrna is generable by emphasizing sparks with high frequency voltage. By applying a high frequency voltage, the spark discharge can increase the speed and the number ofcollisions, Plasma and free radicals are produced by this phenomenon, In order to compare the effect ofigriition, the constant volume combustion chamber that can give a flow was used and took a high-speed video using Schlieren photography. In this study, we report that the improyement ofcombustion in the engine by using a new ignition system applied HF electric field.