This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Numerical and Experimental Analysis of Mixture Formation and Performance in a Direct Injection CNG Engine
Technical Paper
2012-01-0401
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
This paper presents the results of part of the research activity carried out by the Politecnico di Torino and AVL List GmbH as part of the European Community InGAS Collaborative Project. The work was aimed at developing a combustion system for a mono-fuel turbocharged CNG engine, with specific focus on performance, fuel economy and emissions.
A numerical and experimental analysis of the jet development and mixture formation in an optically accessible, single cylinder engine is presented in the paper. The experimental investigations were performed at the AVL laboratories by means of the planar laser-induced fluorescence technique, and revealed a cycle-to-cycle jet shape variability that depended, amongst others, on the injector characteristics and in-cylinder backpressure. Moreover, the mixing mechanism had to be optimized over a wide range of operating conditions, under both stratified lean and homogeneous stoichiometric modes. For this reason the experimental activity was supported by the numerical simulations of CNG injection, jet formation and air-fuel mixing, in order to have a deep insight into the injected gas behavior.
Simulations were carried out at the Politecnico di Torino, within the Star-CD environment, and involved the combustion chamber, the intake port and the exhaust port, in order to account for the actual flow field at the start of injection. Fuel injection was simulated by means of the ‘virtual injector’ approach, which was developed and validated at the Politecnico di Torino. Laser-Induced Fluorescence images were used to validate the numerical results. The model was then applied to a variety of test cases, involving part load and full load operating points.
Combustion system optimization was also carried out by means of an experimental investigation, which was performed by AVL on the performance and emissions of a multi-cylinder engine. The single-cylinder and the multi-cylinder engine are both based on a Mercedes-Benz four-cylinder in-line engine and feature a pent-roof combustion chamber, a bowl in piston and a centrally mounted poppet valve injector.
The numerical and the planar laser-induced fluorescence results obtained on the transparent engine revealed a close dependence of the mixture formation process on the injection timing and injector characteristics, and resulted in rather good agreement with the multi-cylinder engine performance and emission results. In fact, an unsatisfactory mixing degree detected in the former engine corresponded to higher HC emissions and cycle-to-cycle variations of combustion-related quantities in the multi-cylinder engine.
Recommended Content
Authors
Topic
Citation
Baratta, M., Rapetto, N., Spessa, E., Fuerhapter, A. et al., "Numerical and Experimental Analysis of Mixture Formation and Performance in a Direct Injection CNG Engine," SAE Technical Paper 2012-01-0401, 2012, https://doi.org/10.4271/2012-01-0401.Also In
References
- Cho, H.M. He, B.Q. “Spark Ignition Natural Gas Engines - a Review” Energy Conv. and Management 48 608 618 2007
- Korakianitis, T. Namasivayam, A.M. Crookes, R.J. “Natural-gas fueled spark-ignition (SI) and compression-ignition (CI) engine performance and emissions” Progress in Energy and Combustion Science 37 89 112 2011
- Borges, L. Hollnagel, C. Muraro, W. “Development of a Mercedes-Benz Natural Gas Engine M 366 LAG, with a Lean Burn Combustion System,” SAE Technical Paper 962378 1996 10.4271/962378
- Kato, K. Igarashi, K. Masuda, M. Otsubo, K. et al. “Development of Engine for Natural Gas Vehicle,” SAE Technical Paper 1999-01-0574 1999 10.4271/1999-01-0574
- Sobiesiak, A. Zhang, S. “The First and Second Law Analysis of Spark Ignition Engine Fuelled with Compressed Natural Gas,” SAE Technical Paper 2003-01-3091 2003 10.4271/2003-01-3091
- InGAS Annex I “Description of Work”, amendment 3 July 2010
- Baratta, M. Catania, A.E. Pesce, F.C. “CNG Injector Nozzle Design and Flow Prediction” ASME Internal Combustion Engine Division 2010 Fall Technical Conference September 12 15 2010 San Antonio, Texas, USA
- Blotevogel, T. Egermann, J. Goldlücke, J. Leipertz, A. et al. “Developing Planar Laser-Induced Fluorescence for the Investigation of the Mixture Formation Process in Hydrogen Engines,” SAE Technical Paper 2004-01-1408 2004 10.4271/2004-01-1408
- Haslacher, R. Eichlseder, H. Heindl, R. Kirchweger, W. “Optical Instrumentation and 3D CFD Simulation as Development Tools for innovative CNG Combustion Processes” Thermodynamics and Thermal Machines Institute, Technical University of Graz Austria 2007
- Haslacher, R. Kirchweger, W. Eichlseder, H. “Laser-Optical Methods for Diagnostics of NG Combustion Processes with Internal Mixture Formation (in German) 8 th Symposium on Engine Combustion - Current Problems and Modern Approaches Munich, Germany March 15 16 2007
- Star-CD v4.12 Methodology Manual Computational Dynamics Ltd 2009
- Es-ICE v2.16 User Guide Comput. Dynamics Ltd. 2009
- Baratta, M. Catania, A.E. Pesce, F.C. “Multidimensional Modeling of Natural Gas Jet and Mixture Formation in DI SI Engines - Development and Validation of a Virtual Injector Model” ASME Trans., Journal of Fluids Engineering 133 041304 1/14 2011
- Baratta, M. Catania, A.E. Pesce, F.C. “Computational and Experimental Analysis of Direct CNG Injection and Mixture Formation in a SI Research Engine” ASME Internal Combustion Engine Division 2010 Fall Technical Conference September 12 15 2010 San Antonio, Texas, USA
- Scarcelli, R. Wallner, T. Matthias, N. Salazar, V. et al. “Numerical and Optical Evolution of Gaseous Jets in Direct Injection Hydrogen Engines,” SAE Technical Paper 2011-01-0675 2011 10.4271/2011-01-0675
- Baratta, M. Rapetto, N “Fluid-Dynamic and Numerical Aspects in the Simulation of Direct CNG Injection in Spark-Ignition Engines”
- Baratta, M. Catania, A. Spessa, E. Herrmann, L. et al. “Multi-Dimensional Modeling of Direct Natural-Gas Injection and Mixture Formation in a Stratified-Charge SI Engine with Centrally Mounted Injector,” SAE Int. J. Engines 1 1 607 626 2009 10.4271/2008-01-0975
- Eckbreth, A.C. “Laser Diagnostics for Combustion Temperature and Species” 2nd Gordon and Breach Publishers 1996
- Zhao, H. Laddomatos, N. “Optical Diagnostics for In-Cylinder Mixture Formation Measurements in IC Engines” Progr. Energy Combust. Sci. 24 297 336 1998
- Reboux, J. Puechberty, D. Dionnet, F. “A New Approach of Planar Laser Induced Fluorescence Applied to Fuel/Air Ratio Measurement in the Compression Stroke of an Optical S.I. Engine,” SAE Technical Paper 941988 1994 10.4271/941988
- Reboux, J. Puechberty, D. Dionnet, F. “Study of Mixture Inhomogeneities and Combustion Development in a S.I. Engine Using a New Approach of Laser Induced Fluorescence (FARLIF),” SAE Technical Paper 961205 1996 10.4271/961205
- Hishinuma, H. Urushihara, T. Kakuho, A. Itoh, T. “Development of a Technique for Quantifying In-Cylinder A/F Ratio Distribution Using LIF Image Processing” JSAE Review 17 255 259 1996
- Tomita, E. Hamamoto, Y. Yoshiyama, S. Toda, H. “Measurement of Fuel Concentration Distribution of Transient Hydrogen Jet and its Flame Using Planar Laser Induced Fluorescence Method” JSAE Review 19 329 335 1998
- Zhao, F. Taketomi, M. Nishida, K. Hiroyasu, H. “PLIF Measurements of the Cyclic Variation of Mixture Concentration in a SI Engine,” SAE Technical Paper 940988 1994 10.4271/940988
- McGee, J. Alger, T. Blobaum, E. Wooldridge, S. “Evaluation of a Direct-Injected Stratified Charge Combustion System Using Tracer PLIF,” SAE Technical Paper 2004-01-0548 2004 10.4271/2004-01-0548
- Kim, G.H. Kirkpatrick, A. Mitchell, C “Computational Modeling of Natural Gas Injection in a Large Bore Engine” ASME Trans., Journal of Engineering for Gas Turbines and Power 126 656 664 2004