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The Effects of Injection Timing and Diluent Addition on Late-Combustion Soot Burnout in a DI Diesel Engine Based on Simultaneous 2-D Imaging of OH and Soot
Technical Paper
2000-01-0238
ISSN: 0148-7191, e-ISSN: 2688-3627
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SAE 2000 World Congress
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English
Abstract
The effects of injection timing and diluent addition on the late-combustion soot burnout in a direct-injection (DI) diesel engine have been investigated using simultaneous planar imaging of the OH-radical and soot distributions. Measurements were made in an optically accessible DI diesel engine of the heavy-duty size class at a 1680 rpm, high-load operating condition. A dual-laser, dual-camera system was used to obtain the simultaneous “single-shot” images using planar laser-induced fluorescence (PLIF) and planar laser-induced incandescence (PLII) for the OH and soot, respectively. The two laser beams were combined into overlapping laser sheets before being directed into the combustion chamber, and the optical signal was separated into the two cameras by means of an edge filter.
These simultaneous images show the spatial relationship between the remaining hot reaction zones and the remaining soot in the bulk-gases (i.e. away from the combustion chamber walls) during the final stages of the combustion event. The PLII-soot images also provide an indication of the amount of unoxidized soot remaining in the bulk gases. Injection timing retard and N2 diluent addition (simulated EGR) were both found to produce substantial changes in the soot burnout at the conditions investigated. These conditions are representative of those that are typically more problematic for production engines in terms of the soot-NOX tradeoff. The images indicate that incomplete burnout in the bulk gases can result from both insufficient time to complete combustion and extinction of the combustion reactions associated with the remaining soot pockets. Bosch-smoke type engine-out soot measurements were also made, and changes in the engine-out soot with operating conditions were found to correlate with changes in the in-cylinder data. The results strongly suggest that changes in soot burnout in the bulk gases are a major contributor to the increased soot emissions typically observed when timing is retarded and/or diluent is added to reduce NOX in diesel engines at conditions similar to those investigated.
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Citation
Dec, J. and Kelly-Zion, P., "The Effects of Injection Timing and Diluent Addition on Late-Combustion Soot Burnout in a DI Diesel Engine Based on Simultaneous 2-D Imaging of OH and Soot," SAE Technical Paper 2000-01-0238, 2000, https://doi.org/10.4271/2000-01-0238.Also In
Combustion, Flow Diagnostics, and In-Cylinder Velocity Measurement
Number: SP-1529 ; Published: 2000-03-06
Number: SP-1529 ; Published: 2000-03-06
References
- Dec, J. E., and Kelly-Zion, P., “Simultaneous Planar Imaging of OH-Radical and Soot Distributions to Investigate the Late Stages of Diesel Combustion,” submitted to Combustion and Flame, 2000.
- Dec, J. E., “A Conceptual Model of DI Diesel Combustion Based on Laser-Sheet Imaging,” SAE Transactions, Vol. 106, Sec. 3, pp. 1319-1348, paper no. 970873, 1997.
- Heywood, J. B., Internal Combustion Engine Fundamentals, McGraw-Hill, New York, 1988.
- Espey, C. and Dec, J. E., “Diesel Engine Combustion Studies in a Newly Designed Optical-Access Engine Using High-Speed Visualization and 2-D Laser Imaging,” SAE Transactions, Vol. 102, Sec. 4, pp. 703-723, paper no. 930971, 1993.
- Rothrock, A. M. and Waldron, C. D. “Effect of Nozzle Design on Fuel Spray and Flame Formation in a High-Speed Compression-Ignition Engine,” N.A.C.A. report no. 561, 1936.
- Kittelson, D. B., Ambs, J. L., and Hadjkacem, H., “Particulate Emissions from Diesel Engines - Influence of In-Cylinder Surface,” SAE Transactions, Vol. 99, Sec. 3, paper no. 900645, 1990.
- zur Loye, A. O., Siebers, D. L., McKinley, T. L., Ng, H. K., and Primus, R. J., “Cycle-Resolved LDV Measurements in a Motored Diesel Engine and Comparison with k-e Model Predictions,” SAE Transactions, Vol. 98, Sec. 3, pp. 1142-1158, paper no. 890618, 1989.
- Dieke, G. H. and Crosswhite, H. M., “The Ultraviolet Bands of OH Fundamental Data,” J. Quant. Spectrosc. Radiat. Transfer, Vol. 2, pp. 97-199, 1962.
- Melton, L. A., “Soot Diagnostics Based on Laser Heating,” Applied Optics, Vol. 23, No. 13, pp. 2201-2208, 1984.
- Dec, J. E. and Coy, E. B, “OH Radical Imaging in a D.I. Diesel Engine and the Structure of the Early Diffusion Flame,” SAE Transactions, Vol. 105, Sec. 3, pp. 1127-1148, paper no. 960831, 1996.
- Dec, J.E. and Espey, C., “Ignition and Early Soot Formation in a D.I. Diesel Engine Using Multiple 2-D Imaging Diagnostics,” SAE Transactions, Vol. 104, Sec. 3, pp. 853-875, paper no. 950456, 1995.
- Espey, C., Dec, J. E., Litzinger, T. A. and Santavicca, D. A., “Planar Laser Rayleigh Scattering for Quantitative Vapor-Fuel Imaging in a Diesel Jet,” Combustion and Flame, Vol. 109, pp. 65-86, 1997.
- Espey, C. and Dec, J. E., “The Effect of TDC Temperature and Density on the Liquid-Phase Fuel Penetration in a D.I. Diesel Engine,” SAE Transactions, Vol. 104, Sec. 4, pp. 1400-1414, paper no. 952456, 1995.
- Dec, J.E. and Canaan, R. E., “PLIF Imaging of NO Formation in a DI Diesel Engine,” SAE paper no. 980147, SAE Transactions, in press, 1998.
- Flynn, P. F., Durrett, R. P., Hunter, G. L., zur Loye, A. O., Akinyemi, O. C., Dec, J. E., and Westbrook, C. K., “Diesel Combustion: An Integrated View Combining Laser Diagnostics, Chemical Kinetics, and Empirical Validation,” SAE paper no. 1999-01-0509, 1999.
- Personal communication with Durrett Russell, Cummins Engine Co., Columbus, IN.
- Naber, J. D. and Siebers, D. L., “Effects of Gas Density and Vaporization on Penetration and Dispersion of Diesel Sprays,” SAE Transactions, Vol. 105, Sec. 3, pp. 82-111, paper no. 960034, 1996.
- Siebers, D. L., “Scaling Liquid-Phase Fuel Penetration in Diesel Sprays Based on Mixing-Limited Vaporization,” SAE paper no. 1999-01-0528, 1999.
- Homan, H. S., “Conversion Factors among Smoke Measurements,” SAE Transactions, Vol. 94, Sec. 2, pp. 2.533-2.547, paper no. 850267, 1985.