Abstract
A computational and experimental study has been carried out in order to understand comprehensively the effects of reentrant combustion chamber on in-cylinder air flow. First, the computational results from our refined KIVA-II code were compared between toroidal and reentrant bowls in term of swirl preservation inside the cavity. Then, to verify the calculation, an optically accessible DI engine was used to measure the flow fields inside the cavity by laser sheet and image processing technique. These measurements supported the results from calculation. Moreover, by visualizing the combustion process and measuring the flame motion in both chambers, the significant difference in flame motion was also observed. Therefore, the swirl preservation in the reentrant chamber was proved and can be concluded as one of the major factors that improve combustion and emissions.