Stratification of In-cylinder Mixture Distributions by Tuned Port Injection in a 4-valve SI Gas Engine

In order to realize the stratification of mixture within a port injection gas engine, an experimental engine having two intake ports (i. e. swirl and straight port) per cylinder was prepared and investigations were made to see the effect of injection position on in-cylinder fuel distribution. To understand the flow within the engine, CFD calculation and PIV measurement were carried out and the effects were examined. Also firing tests and the measurement of in-cylinder fuel distribution by LIF method were conducted with the various injection positions to verify the predictions. As a result, it was found that the performance of the engine was affected by the injection position and proper charge stratification was realized by injection into a certain area of the intake port.