In-cylinder studies of split injection in a single cylinder optical diesel engine

Abstract

In order to meet the ever more stringent emission standards, significant efforts have been devoted to the research and development of cleaner IC engines. Diesel combustion and the formation of pollutants are directly influenced by spatial and temporal distribution of the fuel injected. This study investigates the effect of dwell timing on the in-cylinder combustion process and emissions through the application of 70%/30% split injection strategy in a single cylinder HSDI optical diesel engine. The fuel injection process was illuminated by a high repetition copper vapour laser and recorded synchronously by a high speed video camera. The combustion temperature and soot distribution during the combustion process were measured by a recently developed high speed two-colour system at the authors laboratory. The results indicated that this injection mode has the potential to improve fuel economy and engine performance while substantially reducing the combustion noise, provided that the injection timings are appropriately selected.