Abstract
In this study, Spray and Combustion Characteristics of Diesel Fuel in the Medium Speed Engines (High ambient pressure and larger nozzle hole diameter compared to Automotive Engines) were clarified. To simulate the ambient density and ambient temperature conditions of the actual engine, optical accessible Rapid Compression Expansion Machine (RCEM) was used. As a result, increasing ambient density and nozzle hole diameter increases spray cone angle. Increase of Spray cone angle shortens ignition delay and ignites upstream of spray. From these results, spray and combustion characteristics on medium speed engines were clarified, which were different from automotive engines.
