Cycle Resolved In-Cylinder Measurements and SOI Optimization of a DISI Engine in Transient Operation

Abstract

The topic of this master’s thesis are cycle and crank angle resolved measurements in a 6 cylinder direct injection spark ignition gasoline engine. The engine is operated in transient mode. This thesis focuses on optical fiber spark plug and ion current measurements. Also pictures of a high speed camera were analyzed. Additionally cylinder pressure and temperatures as well as particulate matter, HC, NO, CO and CO2 emissions were measured. The intention of this research was to gather better knowledge of the combustion process during transient operation and its effects on exhaust emissions. Variations of start of injection, rail pressure, engine load and engine speed were conducted. In the end of this thesis possible use of the gained knowledge is demonstrated. The injection timing was optimized based on signals from the optical fiber spark plug. The goal was the reduction of particle emissions and a smooth combustion process.