ID 414

The influence of nozzle hole manufacturing methods on spray characteristics of multi-hole gasoline fuel injectors

 

Abstract:

Fuel spray characteristics of multi-hole gasoline fuel injectors produced with different manufacturing methods, but with nominally identical nozzle geometries, were compared. Sprays from nozzles with holes produced with Electrical Discharge Machining (EDM) and laser machining were characterized under vaporizing conditions. Nozzle hole geometries were verified for both cases with micro x-ray tomography. Results of the investigation indicate that the hole manufacturing method, and resulting inlet edge characteristics, can have a dramatic impact on spray characteristics. Sharp inlet edges, associated with laser machining, promote an increase in individual spray plume angles and result in significant plume-to-plume interaction resulting in reduced air entrainment. Ultimately, this results in a collapsed spray structure with extended liquid phase persistence.