Study of new prototype pintle injectors for diesel engine application

A new prototype common rail injector featuring a complete new nozzle design concept was exhaustively characterized both from the hydraulic and spray formation point of view. A commercial injection rate meter together with a spray momentum test rig were used to determine the flow characteristics at the nozzle exit. A novel high pressure and high temperature chamber (up to 15 MPa and 1000 K) was used to determine liquid length and vapor penetration. Using these tools, three different pintle nozzle designs, with specific features in the outlet section, were studied. The test matrix included a sweep of injection pressure up to 2000 bar and a sweep of ambient temperature up to 950 K. The results obtained show that pintle nozzles offer great potential in terms of fuel mass flux controlled by variable nozzle geometry. Effects in the hydraulic measurements and spray images due to the variable geometry were observed and characterized.