Multiple Injection in a Mixed Mode GDI Boosted Engine Istituto Motori CNR

Format:

Conference/Event

Author/Creator:

Costa, Costa, author.

Contributor:

Allocca, Luigi

Iorio, B.

Montanaro, Alessandro

Sorge, Ugo

Conference Name:

International Powertrains, Fuels & Lubricants Meeting (2010-05-05 : Rio De Janeiro, Brazil)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2010

Summary:

A numerical investigation is performed with the aim ofunderstanding the potential benefits of multiple injections in themixed mode boosting operation of a Gasoline Direct Injection (GDI)engine. The study is carried out by firstly characterizing a highpressure multi-hole injector from the experimental point of view inthe split injection operation. Measurements of the fuel injectionrate are made through an AVL Meter operating on the Boschprinciple. The injector is tested using gasoline in a double pulsestrategy. The injection pressure is varied between 5.0 and 25.0 MPawith the pulse durations calibrated for delivering a total mass upto 50 mg/str. The choice of the dwell time between two successiveinjection events is achieved by firstly defining the minimum timecompatible with the mechanical characteristics of both the injectorand the injector driver. While the GDI injector driver is able togenerate a proper trigger current without limitations on theduration of the time between consecutive injections, a currentcommand with a too low dwell time would make for the injected fuelto not be split in two separate events.The multidimensional modeling of the in-cylinder processes isrealized within the AVL FIRE code environment. Gasolineinjection is simulated by resorting to a properly developed modelthat uses measured injection mass flow rates and accounts for thedependence of the initial droplets size distribution upon injectionpressure. It is shown that high-speed high-load conditions do notbenefit of splitting injection, whereas two injection events areuseful for improving the quality of mixture stratification atmoderate-speed moderate-load conditions. The choice of the dwelltime between two successive injections is crucial

Notes:

Vendor supplied data

Publisher Number:

2010-01-1496

Access Restriction:

Restricted for use by site license