74 ENGINE SCAVENGING OPTIMIZATION

Automotive pollutant emissions have been drastically restricted during the last ten years. These emission standards are now concerning small two-stroke engine. In order to reach future emission standard, it is essential to improve the scavenging flow, and especially the trapping efficiency of the engines. It is also interesting to have a tool for predicting the scavenging performances of an engine before the firing engine situation, which takes place late in the time scale of a development. A special test bench has been developed by D2T Group to visualize and quantify the scavenging process. It was also modelled with CFD tools, and a good correlation was observed between calculations and experimentations. This shows a good potential to reduce time and money spent in an engine development.