Technical Paper
Experimental Investigation of Spray and Combustion Characteristics by Direct Needle-Driven Diesel Injector in a CRDi Engine
2015-03-10
2015-01-0004
In common rail diesel fuel injector system, currently there are two kinds of servo-hydraulic type piezo-driven injector; 3-way and bypass-circuit type, in order to amplify the extension of the piezo stack. The pilot valve driven by piezo stack can control the flow of fuel at a pressure chamber, which is accurately regulated by 3-way or bypass-circuit mechanism. Even though fuel injection events are triggered electrically, the main actuation forces to move injector needle inside nozzle are hydraulic force which is the key object aimed to eliminate in this study. In this study, two experiments were carried out using a constant volume chamber and a single cylinder CR direct-injection diesel engine. The driving force for air-fuel mixing process in diesel diffusion combustion is the energy contained within the spray.
