AVL's research work on advanced combustion systems for four-stroke gasoline engines has revealed a strong influence of charge motion and mixture preparation on engine performance, especially exhaust emissions and fuel economy.
This paper presents the effects of mixture preparation and charge motion revealed in studies of AVL High Compression Fast Burn (HCFB) combustion systems. Major combustion parameters were investigated and optimized. Control of charge stratification emerged as one of the key elements of advanced combustion systems for both two-valve and four-valve engine configurations. Consequently, measures for charge stratification control are also presented.