Abstract: A process for running an internal combustion engine is disclosed. The process comprises running the engine in communication with ambient air and with a fuel that is, at the compression ratio of the engine, capable of undergoing combustion in air containing a sufficient amount of oxygen for combustion and of undergoing spontaneous explosion in the absence of sufficient oxygen in said air for combustion.

Abstract: A turbojet combustor and method for controlling nitric oxide emissions is provided by employing successive combustion zones wherein after combustion of an initial portion of the fuel in a primary combustion zone, the combustion products of the primary zone are combined with the remaining portion of fuel and additional plenum air and burned in a secondary combustion zone under conditions that result in low nitric oxide emissions. Low nitric oxide emissions are achieved by a novel turbojet combustor arrangement which provides flame stability by allowing stable combustion, which usually result in large emissions of nitric oxide in a primary combustion zone, to be accompanied by low nitric oxide emissions resulting from controlled fuel-lean combustion, ignited by the emission products from the primary zone, in a secondary combustion zone at a lower combustion temperature resulting in low emissions of nitric oxide.