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Numerical Analysis of the Role of Initial Combustion on Reduction of NO and Soot from DI Diesel Engines
ISSN: 0148-7191, e-ISSN: 2688-3627
Published June 19, 2000 by SAE International in United States
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Multidimensional simulation has been carried out to be clear the role of initial combustion in D.I. diesel engines on reduction of NO and soot emissions by reduction of initial injection rate or pilot injection. The multidimensional engine simulation code, FREC-3D(CI), which was developed by IKEGAMI group in Kyoto Univ. at 1988, was modified and was used in this study. The combustion submodel in this code was updated including ignition submodel that was formulated by a one-step global chemical mechanism to simulate measured ignition delay and initial combustion, sufficiently. In-cylinder NO and soot formation models were introduced by present authors. NO and soot were predicted by Zeldovich mechanism and Morel's soot formation and oxidation formulations, respectively. In result, computations demonstrated good agreement between measured and predicted trends of in-cylinder pressure, and rate of heat release, and showed a trade-off relationship between NO and soot emissions at pilot injection with high pressure injection. NO and soot emissions is greatly influenced by a dwell period between pilot and main injections. This is due to that local distributions of temperature and oxygen fraction are changed by a dwell period. Computations also showed that high turbulence kinetic energy in combustion chamber is sustained at the late combustion stage after fuel injection in the case of a higher initial injection rate or a injection without pilot injection, so that the soot oxidation process is promoted at the late combustion stage. And the reason why soot density increases in the case of the pilot injection or the reduced initial injection rate, which is a experimental result in previous study by one of the authors, was clarified by computed results.
CitationYamane, K. and Shimamoto, Y., "Numerical Analysis of the Role of Initial Combustion on Reduction of NO and Soot from DI Diesel Engines," SAE Technical Paper 2000-01-2035, 2000, https://doi.org/10.4271/2000-01-2035.
- Shundoh, S. et al., NOx Reduction from Diesel Combustion Using Pilot Injection with High Pressure Fuel Injection, SAE Paper No.920461, (1992).
- Patterson, M. A. et al., Modeling the Effects of Fuel Injection Characteristics on Diesel Engine Soot and NOx Emissions, SAE Paper No.940523, (1994).
- Pierpont, D. A. et al., Reducing Particulate and NOx Using Multiple Injections and EGR in a D.I. Diesel, SAE Paper No.950217, (1995).
- Ikegami, M., Nakatani, K., Tanaka, S. and Yamane, K., Fuel Injection Rate Shaping and Its Effects on Exhaust Emissions in a Direct-Injection Diesel Engine Using Spool Acceleration Type Injection System, SAE Paper No.970347, SP-1219, (1997), 163-174.
- Shioji, M. and Ikegami, M., A Stochastic Approach for Modeling Diesel Combustion, Proc. in Conference on Mechanism of Nonuniform Combustion, (1990.9), 165-174.
- Ikegami, M., et al., Three-Dimensional Simulation of the Diesel Combustion Process, JSME Int.Journal, Series-II, Vol.31, No.1, (1988), 158-165.
- Nakatani, K., Shioji, M. and Ikegami, M., Stochastic Model for Mixture Formation and Initial Burning of a Diesel Spray, The 14th Internal Combustion Engine Symposium, Japan, (in Japanese) , (1997.8), 61-66.
- Livengood, J.C. and Wu, P.C., Correlation of Autoignition Phenomena in Internal Combustion Engines and Rapid Compression Machines, Proc. 5th Symp. (Int.) on Combust. (1955), 347-356.
- Morel, T. et al., Heat Radiation in D.I. Diesel Engine, SAE Paper, No.860445, (1986).
- Ikegami, M., Yamane, K., Takeuchi, K. and Neichi, T., A High-Pressure Diesel Fuel Injection System Using Spool Acceleration and Oil-Hammering, SAE Trans., Vol. 102, Sec. 3, No.930599, (1993), 743-745.