Abstract
It is necessary to modify port shapes for wall guided gasoline direct injection engine to make stratify mixture distribution. Modification of port shapes affects in-cylinder flow and combustion characteristics. In this study, using PIV method, flow characteristics of a port injection engine, which has two straight ports, shape and direct injection engine, which has a helical and a straight port, compared. Moreover, according to experimental results flow and combustion were calculated for another engine rotation speed. As a result, at medium speed range for DI engine, volumetric efficiency was deteriorated and combustion rate was improved due to increase turbulence intensity.
