STRATIFIED CHARGE COMBUSTION AT A HIGH PRESSURE AND TEMPERATURE USING A CONSTANT-VOLUME COMBUSTION VESSEL. (DEVELOPMENT OF THE COMBUSTION SYSTEM AND EXPERIMENTS ON COMBUSTION).

A constant-volume combustion system has been developed to reproduce direct-injection stratified-charge combustion, which is regarded as a promising concept for lean combustion. A fully premixed mixture consisting of N//2, O//2 and H//2 was ignited to obtain a high pressure and temperature occurring at the top dead center in a real engine. The H//2 in the mixture is oxidized by a part of the O//2; thus, a N//2-H//2O-O//2 mixture can be prepared before the injection of iso-octane fuel. Velocities of the swirling air in the vessel were measured by hot-wire anemometry and combustion was analyzed from schlieren photographs and combustion pressures. The results show that a compromise should be achieved between burning velocity and NOx and HC emissions by adjusting the swirl level.