Proceedings of the 4th IASME / WSEAS International Conference on ENERGY & ENVIRONMENT (EE'09)

In recent years, the type of combustion occurred within engine cylinder plays an important role determiningthe performance and emissions. In the present study, the computational investigation was performed in order tocompare characteristics of homogeneous and stratified combustion in a compressed natural gas direct injection engine.The numerical simulation was performed for single cylinder of the 1.6-liter engine running at wide open throttle at2000 rpm and 4000 rpm, accounting for medium and high loads for light-duty vehicle. The results of ComputationalFluid Dynamic (CFD) shows that calculated data of homogeneous combustion are in good agreement with theexperiment data obtained from previous work single-cylinder engine. Parametric studies are then conducted to addresseffect of some parameters on engine performance. Important parameters analysed include cylinder pressure, enginepower, mass fraction burned, CO, CO2 and NO emissions. It is found that homogeneous combustion has an advantagein producing more performance compared to the stratified condition with drawback on higher emissions level, whilestratified combustion has ability in reducing the exhaust emissions with less performance