Multi-dimensional simulation of scavenging process in two-stroke gasoline engine and optimal design of scavenging system

Multi-dimensional simulation of the scavenging process in a two-stroke engine was used to optimize the scavenging process. Based on the simulation of the scavenging process in the HS-510 prototype engine, a loop flow and a swirl are found in the cylinder. The loop flow near the cylinder wall is strong and helpful to make the exhaust gas out of the cylinder. But the loop flow in the middle of cylinder is too weak to scavenge the exhaust gas. And the swirl reduces the scavenging efficiency. Computational results show that the scavenging efficiency in the prototype is lower than that of ideal scavenging process. A new modified engine with the scavenging system composed of five scavenging ports was designed to improve the scavenging efficiency. The computational results show that there is no swirl in the cylinder. The computational and experimental results also show that the scavenging efficiency of the new engine is improved and the engine power is improved by 11%.