Abstract
PCI (Premixed Compression Ignition) combustion is a potential breakthrough technique to simultaneously reduce NOx and particulate matter in engine exhaust emissions. In addition, it is advantageous for fuel consumption by igniting around a top dead center. Moreover, dual mode combustion concept that combined conventional diesel combustion and PCI combustion was proposed as a practical use means. Noise reduction and sound quality improvement technique when the combustion mode is switched depending on the engine operating condition in dual mode combustion concept were developed as a step toward the practical use of PCI combustion.
