Fuel Spray Pattern Control Using L-Step Nozzle for Swirl-Type Injector

We propose a spray pattern control method for swirl-type injectors in direct injection (DI) gasoline engines. An L-cut orifice nozzle (L-Step nozzle) that produces a horseshoe spray pattern is used to create a rich and lean concentration region. To further control the distribution of fuel, the relationship between the nozzle geometry and the spray pattern is investigated. The mechanism for a horseshoe spray formation is hypothesized and verified through experiment. The spray shape and fuel distribution is found to be controllable by configuring the L-cut step-walls. Furthermore, it is discovered that independent control of rich and lean region distribution is possible by arranging the step-wall position and height.