Experimental and Numerical Investigation on Mixture Formation in a HDDI Diesel Engine With Different Combustion Chamber Geometries Università di Modena

Format:

Conference/Event

Author/Creator:

Fontanesi, Fontanesi, author.

Contributor:

Alfuso, S.

Auriemma, M.

Gagliardi, V.

Malaguti, S.

Montanaro, A.

Conference Name:

7th International Conference on Engines for Automobile (2005-09-11 : Naples, Italy)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Naples, ITALY Consiglio Nazionale delle Ricerche 2005

Summary:

One of the most important phases in the development ofdirect-injected diesel engines is the optimization of the fuelspray evolution within the combustion chamber, since it stronglyinfluences both the engine performance and the pollutant emissions.Aim of the present paper is to provide information about mixtureformation within the combustion chamber of a heavy-duty directinjection (HDDI) diesel engine for marine applications. Sprayevolution, in terms of tip penetration, is at first investigatedunder quiescent conditions, both experimentally and numerically,injecting the fuel in a vessel under ambient temperature andcontrolled gas back-pressure. Results of penetration and images ofthe spray from the optically accessible high-pressure vessel areused to investigate the capabilities of some state-of-the-art spraymodels within the STAR-CD software in correctly capturing sprayshape and propagation.The experimental investigation is carried out using a mechanicalinjection pump equipping a heavy-duty, eight-cylinder engine. Onlyone of its plungers is activated, and the fuel is dischargedthrough a seven-hole nozzle, 0.40 mm in diameter, mounted on amechanical injector. Tests are carried out at two different loadfuel amounts, representing 50%, and 100% respectively, and resultsare used as database for the CFD setup. CFD analyses of the intakeand compression strokes are at first performed in order to comparetwo different combustion chambers and different jet orientationswith respect to the combustion chamber cavities, running the engineunder motored conditions and injecting 50% load fuel amount. Boththe two tested pistons show two-stage deep valve pockets hollowedunder the valve seats projections, but some relevant differencesexist in the piston outer region and in the squish area.Subsequently, full CFD analyses of the intake, compression andcombustion processes are performed for the two different combustionchambers and the previously optimized jet orientation, operatingthe engine at full load, maximum revving speed. Numericalpredictions are used to assess the influence of both combustionchamber shapes on the mixture formation effectiveness and theengine-out emissions

Notes:

Vendor supplied data

Publisher Number:

2005-24-055

Access Restriction:

Restricted for use by site license