The Mixture Response of a Stratified Charge Gasoline Engine with Independent, Twin, Port-Fuel Injector Control Univ. of Brighton

Format:

Conference/Event

Author/Creator:

Begg, Begg, author.

Contributor:

Heikal, M. R.

Lourenco Cardosa, T.P.

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:

An experimental study of the mixture response performance ofnovel, port-fuel injection strategies upon combustion stability ina gasoline engine was undertaken at low engine load and speedconditions in the range of 1.0 bar to 1.8 bar GIMEP and 1000 rpm to1800 rpm. The aim was to improve the thermal efficiency of theengine, by extending the lean limit of combustion stability,through promotion of stable charge stratification. Theinvestigation was carried out using a modified 4-valvesingle-cylinder head, derived from a 4-cylinder, pent-roof,production, gasoline engine. The cylinder head was modified bydividing the intake tract into two, separate and isolated passages;each incorporating a production fuel injector. The fuel injectiontiming and duration were controlled independently for eachinjector. The performance effects of a single or multiple fuelinjection event on a single-sided injector were compared tosimultaneous and phased fuel injection for the pair of injectors,with both open valve or closed valve fuel injection timings. Amodel of the engine, implemented in the Ricardo WAVE software andrefined using in-cylinder pressure data, was used to support thefindings. The initial experimental results showed good agreementwith the model's prediction and baseline data obtained in aprevious study. Analysis of the experimental results for thealternative injection strategies showed that the engine could beoperated with far leaner mixtures at low speeds and loads.Combustion stability, defined for a single-cylinder engine as 10%CoVGIMEP, was improved for each engine condition tested. At1000 rpm and 1.0 bar GIMEP, the lean combustion limit was extendedfrom 14:1 air-to-fuel ratio (AFR) to 17.5:1. At 1500 rpm and 1.5bar GIMEP, the lean combustion limit was extended from 17.5:1 toapproximately 21:1 AFR. At 1800 rpm and 1.8 bar GIMEP, the leancombustion limit was improved from 21:1 AFR to 22:1. The improvedtolerance of the combustion system to charge dilution, due to theoptimized injection strategies, was evaluated for high levels oftrapped residuals. The relevance to conditions required forcontrolled auto-ignition combustion is discussed. Finally, theinfluence of the new strategies upon the rates of heat release andthe combustion duration were evaluated and compared tocycle-resolved measurements of the concentration of unburnthydrocarbons in the exhaust gases

Notes:

Vendor supplied data

Publisher Number:

2010-01-1458

Access Restriction:

Restricted for use by site license