기계식 가변밸브기구를 이용한 가솔린 압축착화엔진의 연비 개선에 관한 연구

CAI (Controlled Auto-Ignition) combustion experiments were conducted with a four-stroke, naturally aspirated, single-cylinder gasoline engine. To realize CAI combustion, internal residual gas fraction was controlled by adjusting intake and exhaust valve lift and valve under-lap using the mechanically variable valve device. Fuel was injected during the valve under-lap period using the direct injection system. For the representative 5 part-load points, the fuel consumption and NOx emission benefits were evaluated.