NUMERICAL-ANALYSIS OF THE DIFFUSION PROCESS OF INTAKE MIXTURE IN DUAL-INTAKE VALVE ENGINES

The diffusion process of the intake mixture (homogeneous mixture of ai r 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 -epsilon turbulence model. The following has been found: When the fuel is supplied into only one intake port in one engine in which a tumbli ng vortex is generated, the intake mixture is localized mainly in half of the combustion chamber and the fuel concentration is stratified. I n another engine in which a swirl is generated by holding one intake v alve closed, a relatively homogeneous mixture or an axially stratified mixture is formed in the combustion chamber, depending on whether fue l supply is early or late.