G070044 Visualization of In-cylinder Flow of a Gasoline HCCI Engine Using Blowdown Supercharging System by PIV Method

Abstract

The objective of this research is to investigate the effect of the EGR guide employed to generate a strong in-cylinder thermal stratification on the recharged EGR gas flow into the cylinder in the gasoline HCCI engine equipped with the blowdown supercharging (BDSC) system. The recharged EGR gas flow was visualized using an optical access engine. A steady gas flow from the exhaust port into the cylinder was visualized via PIV method. The effect of the pressure difference between the exhaust port and the cylinder and the geometry of the EGR guide on the recharged gas flow were investigated. The results indicate that the flow field pattern is largely affected by the EGR guide height, and that an increase in the EGR guide height is effective to generate a strong in-cylinder thermal stratification.