Ignition and Combustion Enhancement by Thermal Plasma

Abstract

Research of a plasma jet (PJ) torch igniter is reviewed as a typical ignition system using thermal (equilibrium) plasma. Advantages of the PJ torch are high temperature and its role as a source of active species such as radicals (O,H,N,..), NOx (NO and NO₂), and fuel fragments (CH, CH₂, ….) which drastically accelerate chemical reactions. The effect of existence of a small amount of such active species in a combustible mixture was numerically investigated by calculation of ignition delay times with full chemical kinetics. Moreover, experimental results of ignition tests by the PJ torch in a supersonic airflow conducted by the author was also introduced.