Abstract: An integrated lean burn stabilizer (ILBS) for initiating combustion in an internal combustion engine by generating and introducing active free radicals into a combustion chamber is provided. Engines equipped with the ILBS can achieve a fuel efficient clean combustion processes with a lean and/or diluted mixture otherwise incapable of auto ignition and provide a controlled start of combustion, in conjunction with early in-cylinder direct injection, late diesel-like in-cylinder direct injection, and mixed fuel functions allowing control of the composition and stratification of the mixture. Controlled aspects of the fuel mixture include the equivalent ratio and fuel reactivity combinations inside the main combustion chamber, thereby allowing the start of combustion and duration of combustion inside the main combustion chamber be optimized for maximum cycle efficiency and specific power output while minimizing emissions.

Abstract: In an internal combustion engine a fuel-air mixture having compression temperatures and pressures sufficiently low as not to support auto ignition, ignition is achieved by injecting igniting active radicals into the air-fuel mixture. In one embodiment the active radicals are provided by withdrawing a portion of the mixture, treating it to produce active radicals in the portion and returning the portion to the mixture. Treatment of the portion typically includes simultaneously injecting, mixing, and compression of a predetermined amount of pilot fuel within the portion.