Numerical Analysis of the Diffusion Process of Intake Mixture in Dual-Intake Valve Engines

The diffusion process of intake mixture (homogeneous mixture of air and gaseous fuel) in the cylinders of dual-intake valve S. I. engines has been analyzed numerically using the GTT and CIP methods and the κ-ε turbulence model. The following have been found : In one engine in which a tumbling vortex is generated. the mixture is localized mainly in half of the combustion chamber : namely, it is stratified when the fuel is supplied into only, one intake port. In another engine in which a swirl is generated by holding one intake valve closed, a relatively homogeneous mixture or an axially-stratified mixture is generated in the chamber depending on early or late fuel supply.