This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Tracer LIF Visualisation Studies of Piston-Top Fuel Films in a Wall-Guided, Low-NOx Diesel Engine
Technical Paper
2008-01-2474
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Tracer laser induced fluorescence (LIF) imaging of piston-top fuel films has been performed within the combustion chamber of an optically-accessible, single cylinder Diesel engine. The first objective of the study was to adapt the tracer LIF technique so as to perform in-cylinder imaging of the fuel films under reacting (i.e. combustion) conditions. The results obtained in a wall-guided, combustion chamber operating under highly dilute, Diesel low temperature combustion (LTC) conditions reveal the significant presence of late-cycle piston-top fuel films. Furthermore, it is believed that these fuel films contribute to engine-out hydrocarbon (HC) emissions via a mechanism of flash boiling.
An attempt was also made to evaluate the role of fuel volatility on fuel film lifetimes. This was achieved by using a 50/50 fuel mixture of two single component fuels whose boiling points correspond to moderately high and low volatility components of standard Diesel fuel. Several fuel tracers were considered such as 5-nonanone, tetramethyl-p-phenylendiamine (TMPD) and naphthalene. Finally, the tracer naphthalene with a boiling point of 218°C, coupled with dodecane (boiling point 216°C) was used to represent the higher volatility component of Diesel fuel. An attempt to trace the lower volatility fuel components using the tracer TMPD (boiling point 260°C) proved unsuccessful due to excessive oxygen-induced quenching of the TMPD fluorescence signal. However, experiments performed with the single component fuel n-tetradecane (boiling point 253°C) revealed significant ‘natural fluorescence’, probably due to the presence of trace impurities within the fuel. These characteristics were exploited so as to allow qualitative studies of the evolution of the lower volatility component of Diesel fuels. The results presented here reveal that late cycle piston-top fuel films are preferentially due to the presence of the lower volatility (i.e. heavier) components of the fuel whilst the LIF signal corresponding to the higher volatility tracer/fuel combination is detected until about mid-way through the expansion stroke clearly suggesting that these lighter components undergo faster evaporation.
On a broader note, the present study highlights the problems/challenges of performing tracer-LIF studies of Diesel-type fuels due to an apparent lack of appropriate high boiling point fuel tracers.
Recommended Content
Authors
Citation
Kashdan, J., "Tracer LIF Visualisation Studies of Piston-Top Fuel Films in a Wall-Guided, Low-NOx Diesel Engine," SAE Technical Paper 2008-01-2474, 2008, https://doi.org/10.4271/2008-01-2474.Also In
References
- Christensen, M. Johansson, B. Hultqvist, A. 2001 “The Effect of Piston Topland Geometry on Emissions of Unburned Hydrocarbons from a Homogeneous Charge Compression Ignition (HCCI) Engine” SAE technical paper, 2001-01-1893
- Aceves, S. M. Flowers, D. L. Espinoza-Loza, F. Martinez-Frias, J. Dibble, R. W. Christensen, M. Johansson, B. Hessel, R. P. 2002 “Piston-Liner Crevice Geometry Effect on HCCI Combustion by Multi-Zone Analysis” SAE technical paper, 2002-01-2869
- Heywood, J. B. “Internal Combustion Engine Fundamentals” McGraw-Hill New York 1988
- Iida, M. Hayashi, M. Foster, D. E. Martin, J. K. 2003 “Characteristics of Homogeneous Charge Compression Ignition (HCCI) Engine Operation for Variations in Compression Ratio, Speed and Intake Temperature while using n-Butane as a Fuel” Trans. ASME 125 472 478 April 2003
- Kashdan, J. T. Mendez, S. Bruneaux, G. 2007 “On the Origin of Unburned Hydrocarbon Emissions in a Wall Guided, Low NOx Diesel Combustion System” SAE technical paper, 2007-01-1836
- Kim, D. Ekoto, I. Colban, W. F. Miles, P. C. 2008 “In-Cylinder CO and UHC Imaging in a Light-Duty Diesel Engine during PPCI Low-Temperature Combustion” SAE technical paper, 2008-01-1602
- Musculus, M. P. B. Lachaux, T. Pickett, L. Idicheria, C. A. 2007 “End-of-Injection Over-mixing and Unburned Hydrocarbon Emissions in Low-Temperature-Combustion Diesel Engines” SAE technical paper, 2007-01-0907
- Le Coz, J-F. Catalano, C. Baritaud, T. 1994 “Application of Laser-Induced Fluorescence for Measuring the Thickness of Liquid Films on Transparent Wall” Proc. 7 th Int. Symp. on Appl. Laser Tech. to Fluid Mech. Lisbon 1994
- Drake, M. Fansler, T. Rosalik, M. 2002 “Quantitative High-Speed Imaging of Piston Fuel Films in Direct-Injection Engines using a Refractive-Index-Matching Technique” Proc. 15th ILASS 2002 Madison, WI
- Lin, M-T. Sick, V. 2004 “Is Toluene a Suitable Fuel Tracer for Fuel Film Measurements” SAE technical paper, 2004-01-1355
- Kashdan, J.T. Docquier, N. Bruneaux, G. 2004 “Mixture Preparation and Combustion via LIEF and LIF of Combustion Radicals in a Direct-Injection, HCCI Diesel Engine” SAE technical paper, 2004-01-2945
- Walter, B. Gatellier, B. 2002 “Development of the High Power NADI Concept Using Dual Mode Diesel Combustion to Achieve Zero NOx and Particulate Emissions” SAE technical paper, 2002-01-1744
- Kashdan, J. T. Papagni, J-F. 2005 “LIF Imaging of Auto-Ignition and Combustion in a Direct-Injection Diesel-Fuelled, HCCI Engine” SAE technical paper, 2005-01-3739
- Schulz, C. Gronki, J. Andersson, S. 2004 “Multi-Species Laser-Based Imaging Measurements in a Diesel Spray” SAE technical paper, 2004-01-1917
- Bruneaux, G. 2007 “Study of the Correlation Between Mixing and Auto-ignition Processes in High Pressure Diesel Jets” SAE technical paper, 2007-01-0650
- Vargaftik, N. B. Vinogradov, Y. K. Yargin, V. S. “Handbook of Physical Properties of Liquids and Gases: Pure Substances and Mixtures” 3rd Begell House 1996
- Gaydon, A. G. “The Spectroscopy of Flames” 2nd Chapman and Hall London 1974
- Docquier, N. “Influence of Fresh Charge Preparation and Composition on Auto-Ignition Delays and Combustion Development in an Optical HCCI Direct Injection Diesel Engine” SAE Paper 2003-01-3174
- Persson, F. Försth, M. Rosén, A. 2002 “A Survey of Model Fuel Mixtures Suitable for Exciplex-Spectroscopy for Liquid/Vapor Visualization” Proc. ILASS-Europe 2002 Zaragoza 9-11 Sept. 2002
- Schulz, C. Sick, V. 2005 “Tracer-LIF diagnostics: Quantitative measurement of fuel concentration, temperature and fuel/air ratio in practical combustion systems” Prog. in Energy & Comb. Sci. 31 2005 75 121
- Maly, R. R. Schaefer, V. Hass, H. Cahill, G. F. Rouveirolles, P. Röj, A. Wegener, R. Montagne, X. Di Pancrazio, A. Kashdan, J. 2007 “Optimum Diesel Fuel for Future Clean Diesel Engines” SAE technical paper, 2007-01-0035