Improvement of Mixture Formation in a Uniflow-Scavenged Two-Stroke Engine

After a brief introduction on the importance of mixture formation in diesel engines and the contribution of uniflow scavenging to it, the physical properties of rotary flow induced by uniflow scavenging are considered. The velocity and acceleration fields of rotational and potential flows, which form part of the rotary flow, are determined.

The well-known feature of rotary flow is the separation of particles, which has a negative effect on mixture formation. The mathematical solution to this problem being very complicated, the experimental method of using the scavenging model has been choosen.

The theoretical considerations and the experimental results obtained have yielded sufficient information to determine the guidelines for designing improved fuel injection nozzles. Engine tests have contributed to finding nozzles with a suitable hole configuration for better engine performance.