Browse Publications Technical Papers 2002-01-1132

Study of the Benefits and Drawbacks of a Substantial Increase of Rail-Pressure in GDI-Injector Assemblies 2002-01-1132

In the present paper are examined the consequences of a substantial rise in the injection pressure for Gasoline Direct Injection (GDI) injector assemblies. The paper presents a comparative study of the spray behavior of two different injector nozzle layouts submitted to current 10 Mpa rail-pressure as well as to a 30 Mpa injection pressure. To evaluate the differences in the fundamental physical spray parameters are used several specially developed optical visualization techniques, which enable phase-Doppler, PIV, Laser-sheet and high-speed recordings of dense high pressure fuel sprays. A recently developed injector actuator and the necessary modifications to existing high-pressure pumps to reach a 30 MPa pressure level in the fuel system are presented. The change in basic spray parameters (time-resolved droplet distribution and spray momentum) caused by the rail-pressure rise is examined. Furthermore the impact on the combustion behavior is studied with a 3D-numerical simulation code NCF-3D as well as on a fired GDI-engine test bed. The paper concludes with a discussion of the degree of improvement, which can be expected for a GDI lean-burn system layout, when a 30 MPa rail-pressure is applied. Finally the production costs and complexity of new higher performance components are compared to the possible improvement their introduction can offer.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 17% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:

A Numerical Model for Flash Boiling of Gasoline-Ethanol Blends in Fuel Injector Nozzles


View Details


Air/Fuel Distribution Simulation in a Port Injected Gasoline Lean-burn Engine


View Details


Development of a Mechanical Pilot Injection Device for Automotive Diesel Engines


View Details