Experimental Characterization of Flat-Spray Injector in Gasoline Direct Injection Engines

We propose a flat spray pattern to improve conventional stratified-charge combustion systems in a direct-injection (DI) gasoline engine. Swirl-type DI fuel injectors with a V-groove cut orifice nozzle (V-groove nozzle) and a rectangular-groove cut orifice nozzle (U-groove nozzle) are newly designed. We examine experimentally the characteristics of newly designed injector nozzles under various ambient pressure and fuel pressure conditions. The fuel spray characteristics were tested inside an experimental pressure chamber. The resulting spray patterns were illuminated by YAG-laser sheet and recorded by CCD cameras. The atomization of fuel-spray in the V-groove and U-groove nozzle was also investigated. These experiments showed that the V-groove and the U-groove nozzles generate a well-atomized flat fuel-spray pattern that can be controlled by the orifice-depth and it is robust under ambient pressure variations.