The improvements of the solenoid injector and of the electronic control unit of the present common rail (CR) injection system allow the use of multiple sequential injections. Thanks to this feature this advanced common rail system is capable of performing up to five consecutive injections in one engine cycle, thus improving control of the combustion process. In particular, at some operating conditions, activation of a small injection after the main one allows soot produced in the previous stages of the combustion process to be oxidized without increasing nitrogen oxide emissions. This paper describes the experimental results obtained with the application of a prototype of this advanced common rail system both to a Fiat 1.9 JTD eight-valve four-cylinder engine and to a single-cylinder prototype having the same combustion system and large optical access, allowing investigation of the injection and combustion processes. Multidimensional modelling of the combustion process and pollutant formation was also employed to interpret the trends observed in the experiments.
ImarisioR.RossiG. M.Potential of future common rail DI diesel engines. In Proceedings of International Symposium on The Future of Diesel Engine Technology for Passenger Cars, Porto Cervo, Italy, 12-13 October 2000, Paper 20A2004.
2.
KollmannK.Development trends for diesel powered passenger cars. In Proceedings of International Symposium on The Future of Diesel Engine Technology for Passenger Cars, Porto Cervo, Italy, 12-13 October 2000, Paper 20A2003.
3.
ImarisioR.RiccoM.Rossi SebastianoG. M.Multiple injection, a cost effective solution for emission reduction of common rail DI diesel engines. In Proceedings of Aachener Kolloquium, Aachen, Germany, 4-6 October 2000
4.
HummelK.KriegerK.HansenN.Evolution of the Bosch common rail system for passenger cars. In Proceedings of International Symposium on The Future of Diesel Engine Technology for Passenger Cars, Porto Cervo, Italy, 12-13 October 2000, Paper 20A2012.
5.
MeissonnierG.BazinetV.Injection control in an advanced common rail injection system. In Proceedings of International Symposium on The Future of Diesel Engine Technology for Passenger Cars, Porto Cervo, Italy, 12-13 October 2000, Paper 20A2014.
BakenhusM.ReitzR. D.Two-color combustion visualization of single and split injection in a single-cylinder heavy-duty D.I. diesel engine using an endoscope-based imaging system. SAE Paper 1999-01-1112, 1999.
8.
HanZ.UludoganA.HampsonG. J.ReitzR. D.Mechanism of soot and NOx emission reduction using multiple-injection in a diesel engine. SAE Paper 960633, 1996.
9.
SchommersJ.DuvinageF.StotzM.PetersA.EllwangerS.KoyanagiK.GildenH.Potential of common rail injection system for passenger car DI diesel engine. SAE Paper 2000-01-0944, 2000.
10.
LisbonaM. G.OlmoL.RindoneG.Analysis of the effect of combustion bowl geometry of a DI diesel engine on efficiency and emissions. In Proceedings of Conference on Thermofluid Dynamic Processes in Diesel Engines, Valencia, Spain, 2000.
11.
BeatriceC.BertoliC.Del GiacomoN.MassoliP.MigliaccioM.na.Combustion behavior analysis in a transparent research engine equipped with a common rail diesel injection system. SAE Paper 2000-01-1825, 2000.
12.
BeatriceC.BelardiniP.BertoliC.LisbonaM. G.MigliaccioM.na.Combustion patterns in common rail d.i. engines inferred by experiments and C.F.D. computations. Combust. Sci. Technol., 2001, 162, 235–261.
13.
KoyanagiK.OingH.RennerG.MalyR.Optimizing common rail-injection by optical diagnostics in a transparent production type diesel engine. SAE Paper 1999-01-3646, 1999.
14.
HasseC.BarthsH.PetersN.Modelling the effect of split injections in diesel engines using representative interactive flamelets. SAE Paper 1999-01-3547, 1999.
15.
AmsdenA. A.KIVA-3V: A block structured KIVA program for engines with vertical or canted valves. LA-13313-MS, Los Alamos, 1997.
16.
HanZ.ReitzR. D.Turbulence modelling of internal combustion engines using RNG k-ε models. Combust. Sci. Technol., 1995, 106, 267.
17.
BelardiniP.BertoliC.CamerettiM. C.Numerical analysis of the influence of the jet breakup model formulation on diesel engine combustion computations. Atomization and Sprays Technol., 1998, 8(2), 123–154.
18.
ReitzR. D.Modelling atomisation processes in high-pressure vaporising sprays. Atomization and Sprays Technol., 1987, 3, 309–337.
19.
O'RourkeP. J.AmsdenA. A.The Tab method for numerical calculation of spray droplet break-up. SAE Paper 872089, 1987.
20.
BertoliC.MigliaccioM.na.A finite conductivity model for diesel spray evaporation. Int. J. Heat and Fluid Flow, 1999, 20(5), 552–561.
21.
HiroyasuH.NishidaK.Simplified three dimensional modelling of mixture formation and combustion in a D.I. diesel engine. SAE Paper 890269, 1989.
22.
HandenbergH. O.HaseF. W.An empirical formula for computing pressure rise delay of a fuel from its cetane number and from relevant parameters of D.I. diesel engines. SAE Paper 790493, 1979.
23.
BowmanC. T.Kinetics of pollutant formation and destruction in combustion. Prog. Energy Combust. Sci., 1975, 1, 33–45.
24.
BelardiniP.BertoliC.BeatriceC.D'AnnaA.Del GiacomoN.Application of a reduced kinetic model for soot formation and burnout in three-dimensional diesel combustion computations. In Twenty-Sixth International Symposium on Combustion, 1996, pp. 2517–2524 (The Combustion Institute, Pittsburgh, Pennsylvania).
25.
BelardiniP.BertoliC.Del GiacomoN.CamerettiM. C.A simple autoignition model for 3D diesel combustion computations. In IMechE Third International Conference on Computers in Reciprocating Engines and Gas Turbines, London, 1996, Publication 1996-1, Paper C499/047, pp. 305–315.
26.
BeatriceC.BertoliC.MincioneG.A common rail hydraulic simulation code for injection characteristics investigation: Implementation and preliminary results. In Proceedings of 16th Annual Conference on Liquid Atomization and Spray Systems (ILASS Europe 2000), Darmstadt, Germany, 2000, Paper I.5.
27.
KongS. C.SenecalP. K.ReitzR. D.Developments in spray modeling in diesel and direct-injection gasoline engines. Oil and Gas Sci. Technol.—Rev. IFP, 1999, 54(2), 197–204.
