Influence of nozzle geometry on spray and combustion characteristics related to large two-stroke engine fuel injection systems

As emission regulations for large two-stroke marine Diesel engines increase as well, the manufacturers face similar problems small-sized engine builders. The fuel injection, spray formation and subsequent combustion process remain among main drivers emissions of direct-injection, compression-ignition internal engines. Since injection nozzle design differs significantly, not only in size but especially regarding their non-symmetricity eccentrical orifice arrangement, compared with four-stroke engines, bulk research available related to this topic is very limited. To further deepen understanding how in-nozzle cavitation flow during affects behaviour transparent geometries have been used link phenomena characteristics. A total six single-orifice nozzles based on original five-orifice injectors, without hydro-erosive grinding, experimentally investigated under realistic conditions using highspeed optical measurement techniques a unique constant-volume chamber that geometrically represents at top dead centre. morphology results reveal significant differences between non- ground geometries. While standard angled versions similar, its distinctive swirl pattern behaves differently, leading reliable start ignition extreme wide angle.