Investigation of the Ignition Process of Pilot Injections Using 3D CFD
State of the art high-pressure fuel injectors offer the ability to inject multiple times per cycle, and can reach very low fuel amounts per injection event. This behaviour allows the application of pilot injections in diesel engine applications or dual fuel engines. In both diesel and dual fuel engines, the amount of pilot fuel affects the engine efficiency. The understanding of the underlying ignition mechanism of the pilot fuel is required to optimize injection parameters and the engines’ fuel consumption. The present work focuses on the differences of ignition mechanisms between long and short injections. The investigation has been performed numerically, using 3D CFD with a well-proven combustion model. The setup used contained a well characterized single orifice injector, injecting into a high temperature, pressurized environment with the composition of oxygen (15%) and nitrogen.