Influence of scavenging port parameters on scavenging process in opposed-piston two-stroke diesel engine

To improve the scavenging efficiency of the opposed-piston two-stroke diesel engine, impact of geometry parameters on scavenging process was analyzed. A 1-D simulation model was established based on GT-Power to study influence of port height and circumferential utilization rate, meanwhile CFD model was also established based on AVL-FIRE to study influence of port radial obliquity. Results show that scavenging port opening area is the main factor influencing scavenging mass flow, the larger the opening area, the more the scavenging mass flow. Proper port radial obliquity can increase scavenging flow velocity; while undue port radial obliquity can also lead to flow resistance increase resulting in reducing scavenging efficiency. At the port radial obliquity 20 °CA, max. scavenging efficiency is achieved.