Characteristics of Combustion in Lean Mixtures Initiated by an Imploding Detonation Plug

This paper describes the performance of an Imploding Detonation (ID) plug to ignite a lean methane-air mixture at high pressure and high temperature using a compact Rapid Compression Machine (RCM). The effects of the oxygen enrichment in the ID plug on the combustion characteristics in a combustion chamber were examined, varying oxygen fraction from 32 % to 40 %. The increase in oxygen fraction brought the increase in the burning velocity of the mixture in the ID plug, and thus the induction time of the imploding detonation was reduced. The increase in oxygen fraction also brought the increase in the momentum of the combustion jet that issued from the nozzle of the ID plug into the combustion chamber.