Atomization Characteristics of Two-Stream Injector for 4-Valve Engines

A fuel injector adapter which can divide the fuel spray into two streams and produce fine fuel atomization is being developed to improve fuel economy and transient performance in four-valve gasoline engines. The adapter has the shape of a pair of spectacles and is attached to the orifice outlet of the injector. The optimum shape of the adaptor is investigated by 3-D viscous flow analysis by FEM and experiment. A 17% improvement in transient performance over the conventional Hitachi injector is confirmed by engine tests in a passenger car.