Microwave-assisted plasma ignition system (MAPIS) for a spark ignition engine

Abstract

In this study, effects of microwave ejection on flame kernel formation and development were investigated in a constant volume combustion chamber (CVCC). A magnetron (700W, 2.45 GHz) from conventional microwave oven was utilized as a source. The magnetron was installed in a transmission system composed of waveguide, 3-stub tuner, mixer unit, and coaxial cable. For the ignitor, non-resistor spark plug was utilized. From the result, the microwave assisted plasma ignition system (MAPIS) enhanced the flame speed up to 20% with lean mixture. The lean limit also extended compared to conventional spark ignition case. The enhancement on ignition was decreased with higher ambient pressure and equivalence ratio, however, the benefits were remained with higher microwave input energy.