This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Spray and Self-Ignition Visualization in a DI Diesel Engine
Annotation ability available
Sector:
Language:
English
Abstract
In a DI Diesel engine with optical access, spray and self-ignition were visualized. The engine was designed to provide a large optical access, no spray impingement and thermodynamic conditions close to those of commercial engines. The spray from a single-hole injector and the combustion zone can be fully observed. Laser induced exciplex fluorescence is used to provide information on the spray structure as well as penetration. Luminous emission from the burnt gases served as a marker of the self-ignition sites. The flow field was characterized with laser anemometry.
Data from these three techniques were collected for a set of operating conditions involving changes of air temperature, pressure in the cylinder, injected quantity and engine speed. The effect of varying these parameters is discussed. At the beginning of spray penetration, the liquid and vapor advance at the same speed. Quite soon, the liquid phase stops its progression while the gas phase continues to progress. Self-ignition occurs in a region of high mean shear quite close to the nozzle, often close to the liquid phase tip. This was explained by the presence of coherent strucures in the liquid spray creating favorable self-ignition sites. This mechanism was confirmed by simultaneous self-ignition and liquid Mie scattering visualizations.
Recommended Content
Authors
Topic
Citation
Baritaud, T., Heinze, T., and Le Coz, J., "Spray and Self-Ignition Visualization in a DI Diesel Engine," SAE Technical Paper 940681, 1994, https://doi.org/10.4271/940681.Also In
References
- Baritaud T.A. “Combustion and Fluid Dynamic Measurements in a Spark Ignition Engine: Effects of Thermochemistry and Velocity Fields; Turbulent Flame Speeds” SAE Paper 892098 1989
- Baritaud, T.A. Trapy, J. Monreal, J. “Effects of Swirl and Combustion in a Spark-Ignited Engine” Laser Anemometry in Fluid Mechanics 1988
- Melton, L.A. Verdieck, J.F. “Vapor/Liquid Visualization for Fuel Sprays,” Comb. Sci. & Tech. 42 217 1985
- Bardsley, M.E.A. Felton, P.G. Bracco, F.V. “2-D Visualization of Liquid and Vapor Fuel in an I.C. Engine,” SAE Paper 880521
- Roosen, P. Knoche, K.F. ‘In-situ Measurements of Liquid and Evaporated Fuel in a Model Diesel Injection Spray,” 23rd Symp. Intl. on Comb. Orléans, France 1990
- Rotunno, A.A. Winter, M.A. Dobbs, G.M. Melton, L.A. “Direct Calibration Procedures for Exciplex-Based Vapor/Liquid Visulization of Fuel Sprays,” Comb. Scie. & Tech. 71 247 1990
- Yeh, C. Kamimoto, T. Kobori, S. Kosaka, H. “2-D Imaging of Fuel Vapor Concentration in a Diesel Spray via Exciplex-Based Fluorescence Technique” SAE Paper 932652 1993
- Felton, P.G. Bracco, F.V. Bardsley, M.E.A. “On the Quantitative Application of Exciplex Fluorescence to Engine Sprays” SAE Paper 930870 1993
- Roosen, P. Fiedler, E Megahed, M. Structure Investigation of Diesel Fuel, Sprays, Zwischenbericht zum EG-Project IDEAS Turbulenz, LTT Aachen 03 1990
- Gülder, O.L. Smallwood G.J. Snelling, D.R. “Diesel Spray Structure Investigation by Laser Diffraction and Sheet Illumination” SAE Paper 920577 1992
- Kamimoto, T. Yamane, Y. Kosaka, H. Kobayashi, H. “Numerical Simulation of Turbulent Mixing in a Transient Jet” SAE Paper 93657 1993
- Bracewell, R. The Fourier Transform and its Applications 2nd McGraw-Hill New York 1986
- Hodges, J.T. Baritaud, T.A. Heinze, T.A. “Planar Liquid and Gas Fuel and Droplet Size Visualization in a DI Diesel Engine” SAE Paper 910726 1991
- Edwards, C.F. Siebers, D.L. Hoskin, D.H. “A Study of the Autoignition Process of a Diesel Spray via High Speed Visualization” SAE Paper 92018 1992