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

Abstract

The diffusion process of the 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 k-ε turbulence model. The following has been found : When the fuel is supplied into only one intake port in one engine in which a tumbling vortex is generated, the intake mixture is localized mainly in half of the combustion chamber and the fuel concentration is stratified. 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 formed in the combustion chamber, depending on whether fuel supply is early or late.