Optimization of next generation high flow gasoline direct injection

Engine downsizing, using turbocharging in combination with a reduced number of cylinders, increases power density and leads to high injector flow rate requirements. High flow rates, combined with the trend towards increased system pressures, present a particular development challenge for the injector hardware. This paper describes the approach followed to develop a competitive next generation high flow GDi injector. The higher pressure capable injector has been optimized in particular from the magnetic circuit and the flow path point of views. Increased magnetic forces are required to operate under high pressure conditions and reduced internal pressure drops enable optimal performance under high flow conditions. In addition, hydraulic flow passages and interfaces have to be optimized to achieve the required injector dynamics. Finally, the injector nozzle needs particular attention to achieve optimal flow and spray performance in order to enable ultimate combustion efficiency across the pressure range.