A Computational Fluid Dynamics Study of the Swirl Generation Analysisin Four-stroke Direct Injection Engine

摘要

In this study, the Computational Fluid Dynamics (CFD) simulation to investigate the effect of two piston crowns to the field inside the combustion chamber of a four-stroke direct injection automotive engine when at the motoring condition. The field flow into the chamber for air-fuel mixing to obtain the better swirl ratio, engine combustion, performance and efficiency when the swirl is appeared. So this analysis is important on this study of the effect of the piston shapes to the fluid flow and the air into the cylinder, The behaviors of fluid flow occurred inside combustion chamber is represented by two parameters which influences the air streams to the cylinder during intake stroke and improves the swirl of the air-fuel to produce better air-fuel mixing during the compression stroke. To investigate the effect of air-fuel swirl when change the intake valves conditions and the piston crown shapes. The numerical simulation analysis can be showed the swirl ratio when the air-fuel into the combustion chamber that the condition of the intake valves and the shapes of the piston crown in the combustion chamber by use the Computational Fluid Dynamics (CFD) mode.