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Experimental Investigation of Cyclic Variability on Combustion and Emissions of a High-Speed SI Engine
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 14, 2015 by SAE International in United States
Annotation ability available
Cyclic combustion variability (CCV) is an undesirable characteristic of spark ignition (SI) engines, and originates from variations in gas motion and turbulence, as well as from differences in mixture composition and homogeneity in each cycle. In this work, the cycle to cycle variability on combustion and emissions is experimentally investigated on a high-speed, port fuel injected, spark ignition engine. Fast response analyzers were placed at the exhaust manifold, directly downstream of the exhaust valve of one cylinder, for the determination of the cycle-resolved carbon monoxide (CO) and nitric oxide (NO) emissions. A piezoelectric transducer, integrated in the spark-plug, was also used for cylinder pressure measurement. The impact of engine operating parameters, namely engine speed, load, equivalence ratio and ignition timing on combustion and emissions variability, was evaluated. The variations in mixture stoichiometry were found to have a strong effect on engine combustion variability. Rich cyclic mixture compositions exhibit lower coefficient of variation (COV) for the indicated mean effective pressure (IMEP) and NO emissions (COVNO) compared with lean mixtures. The mean value of CO emission was found to be mainly affected by stoichiometry while COVCO is affected by lambda fluctuations. At higher engine loads, maximum cylinder pressure and IMEP are increased, while COVIMEP decreased. Furthermore, ignition timing was found to strongly affect combustion and NO emissions, as it is related with early flame kernel development and thereby with flame propagation. Maximum braking torque (MBT) operation exhibits maximum IMEP and minimum COVIMEP. Compared to MBT operating conditions, advanced ignition timing leads to higher maximum cylinder pressure, higher NO and COVNO, while retarded ignition timings lead to lower maximum cylinder pressure, lower NO concentration and higher NO variability (COVNO).
CitationKarvountzis-Kontakiotis, A., Ntziachristos, L., Samaras, Z., Dimaratos, A. et al., "Experimental Investigation of Cyclic Variability on Combustion and Emissions of a High-Speed SI Engine," SAE Technical Paper 2015-01-0742, 2015, https://doi.org/10.4271/2015-01-0742.
- Matekunas, F., “Modes and Measures of Cyclic Combustion Variability,” SAE Technical Paper 830337, 1983, doi:10.4271/830337.
- Daw, C., Finney, C., Green, J., Kennel, M. et al., “A Simple Model for Cyclic Variations in a Spark-Ignition Engine,” SAE Technical Paper 962086, 1996, doi:10.4271/962086.
- Roberts, J., Jones, J., and Landsborough, K., “Cylinder Pressure Variations as a Stochastic Process,” SAE Technical Paper 970059, 1997, doi:10.4271/970059.
- Ozdor, N., Dulger, M., and Sher, E., “Cyclic Variability in Spark Ignition Engines A Literature Survey,” SAE Technical Paper 940987, 1994, doi:10.4271/940987.
- Young, M., “Cyclic Dispersion - Some Quantitative Cause-and- Effect Relationships,” SAE Technical Paper 800459, 1980, doi:10.4271/800459.
- Ball, J. K., Raine, R. R., and Stone, C. R., “Combustion analysis and cycle-by-cycle variations in spark ignition engine combustion Part 2: a new parameter for completeness of combustion and its use in modelling cycle-by-cycle variations in combustion,” Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, vol. 212, pp. 507-523, 1998, doi:10.1243/0954407981526145.
- Ozdor, N., Dulger, M., and Sher, E., “An Experimental Study of the Cyclic Variability in Spark Ignition Engines,” SAE Technical Paper 960611, 1996, doi:10.4271/960611.
- Grünefeld, G., Beushausen, V., Andresen, P., and Hentschel, W., “A Major Origin of Cyclic Energy Conversion Variations in SI Engines: Cycle-by-Cycle Variations of the Equivalence Ratio and Residual Gas of the Initial Charge,” SAE Technical Paper 941880, 1994, doi:10.4271/941880.
- Li, C., Duan, Q., Maroteaux, F., and Murat, M., “Time-Resolved Measurement of Fuel Transient Behaviour and Cycle to Cycle Variation of Local Fuel/Air Equivalence Ratio in Gasoline Engines,” SAE Technical Paper 940989, 1994, doi:10.4271/940989.
- Mehrani, P. and Watson, H., “Exploring the Geometric Effects of Turbulence on Cyclic Variability,” SAE Technical Paper 2010-01-0540, 2010, doi:10.4271/2010-01-0540.
- Mehrani, P. and Watson, H., “Modeling the Effects of Mixture Composition on Cyclic Variability,” SAE Technical Paper 2007-01-0672, 2007, doi:10.4271/2007-01-0672.
- Johansson, B., “Cycle to Cycle Variations in S.I. Engines - The Effects of Fluid Flow and Gas Composition in the Vicinity of the Spark Plug on Early Combustion,” SAE Technical Paper 962084, 1996, doi:10.4271/962084.
- Stone, R., Introduction to Internal Combustion Engines, Palgrave Macmillan, United Kingdom, 2012.
- Hill, P. G., “Cyclic variations and turbulence structure in spark-ignition engines,” Combust. Flame, vol. 72, pp. 73-89, 1988, doi:10.1016/0010-2180(88)90098-3.
- Aleiferis, P. G., Taylor, A. M. K. P., Ishii, K., and Urata, Y., “The nature of early flame development in a lean-burn stratified-charge spark-ignition engine,” Combust. Flame, vol. 136, pp. 283-302, 2004, doi:10.1016/j.combustflame.2003.08.011.
- Aleiferis, P., Taylor, A., Whitelaw, J., Ishii, K. et al., “Cyclic Variations of Initial Flame Kernel Growth in a Honda VTEC-E Lean-Burn Spark-Ignition Engine,” SAE Technical Paper 2000-01-1207, 2000, doi:10.4271/2000-01-1207.
- Brehob, D. and Newman, C., “Monte Carlo Simulation of Cycle by Cycle Variability,” SAE Technical Paper 922165, 1992, doi:10.4271/922165.
- Ball, J. K., Stone, C. R., and Collings, N., “Cycle-by-cycle modelling of NO formation and comparison with experimental data,” Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, vol. 213, pp. 175-189, 1999, doi:10.1243/0954407991526784.
- Watson, H., Goldsworthy, L., and Milkins, E., “Cycle by Cycle Variations of HC, CO, and NOX,” SAE Technical Paper 760753, 1976, doi:10.4271/760753.
- Karvountzis-Kontakiotis, A. and Ntziachristos, L., “A detailed chemical mechanism to predict NO cycle-to-cycle variation in homogeneous engine combustion,” E-COSM'12 - IFAC Workshop on Engine and Powertrain Control, Simulation and Modeling, vol. 3, pp. 408-415, 2012, doi:10.3182/20121023-3-FR-4025.00046.
- Karvountzis-Kontakiotis, A. and Ntziachristos, L., “Investigation of Cycle-to-Cycle Variability of NO in Homogeneous Combustion,” Oil & Gas Science and Technology, 2014, doi:10.2516/ogst/2013199.
- Peckham, M., Finch, A., and Campbell, B., “Analysis of Transient HC, CO, NOx and CO2 Emissions from a GDI Engine using Fast Response Gas Analyzers,” SAE Int. J. Engines 4(1):1513-1522, 2011, doi:10.4271/2011-01-1227.
- Rakopoulos, C., Dimaratos, A., Giakoumis, E., and Peckham, M., “Experimental Assessment of Turbocharged Diesel Engine Transient Emissions during Acceleration, Load Change and Starting,” SAE Technical Paper 2010-01-1287, 2010, doi:10.4271/2010-01-1287.
- Davis, P. and Peckham, M., “Measurement of Cycle-by-Cycle AFR using a Fast Response NDIR Analyzer for Cold Start Fuelling Calibration Applications,” SAE Technical Paper 2006-01-1515, 2006, doi:10.4271/2006-01-1515.
- Davis, P. and Peckham, M., “Cycle-by-Cycle Gasoline Engine Cold Start Measurement of Residual Gas and AFR Using a Fast Response CO&CO2 Analyzer,” SAE Technical Paper 2008-01-1649, 2008, doi:10.4271/2008-01-1649.
- Baltisberger, S. and Ruhm, K., “Fast NO Measuring Device for Internal Combustion Engines,” SAE Technical Paper 940962, 1994, doi:10.4271/940962.
- Heywood, J., Internal Combustion Engine Fundamentals, McGraw-Hill, New York, 1988.
- Egnell, R., “Combustion Diagnostics by Means of Multizone Heat Release Analysis and NO Calculation,” SAE Technical Paper 981424, 1998, doi:10.4271/981424.
- Ceviz, M. A. and Kaymaz, İ., “Temperature and air-fuel ratio dependent specific heat ratio functions for lean burned and unburned mixture,” Energy Conversion and Management, vol. 46, pp. 2387-2404, 2004, doi:10.1016/j.enconman.2004.12.009.
- Han, S., Chung, Y., Kwon, Y., and Lee, S., “Empirical Formula for Instantaneous Heat Transfer Coefficient in Spark Ignition Engine,” SAE Technical Paper 972995, 1997, doi:10.4271/972995.
- Brettschneider, J., “Extension of the Equation for Calculation of the Air-Fuel Equivalence Ratio,” SAE Technical Paper 972989, 1997, doi:10.4271/972989.
- Ball, J., Bowe, M., Stone, C., and Collings, N., “Validation of a Cyclic NO Formation Model with Fast NO Measurements,” SAE Technical Paper 2001-01-1010, 2001, doi:10.4271/2001-01-1010.
- Reavell, K., Collings, N., Peckham, M., and Hands, T., “Simultaneous Fast Response NO and HC Measurements from a Spark Ignition Engine,” SAE Technical Paper 971610, 1997, doi:10.4271/971610.
- Alger, T., Gingrich, J., Mangold, B., and Roberts, C., “A Continuous Discharge Ignition System for EGR Limit Extension in SI Engines,” SAE Int. J. Engines 4(1):677-692, 2011, doi:10.4271/2011-01-0661.
- Chen, W., Madison, D., Dice, P., Naber, J. et al., “Impact of Ignition Energy Phasing and Spark Gap on Combustion in a Homogenous Direct Injection Gasoline SI Engine Near the EGR Limit,” SAE Technical Paper 2013-01-1630, 2013, doi:10.4271/2013-01-1630.
- Heywood, J., Higgins, J., Watts, P., and Tabaczynski, R., “Development and Use of a Cycle Simulation to Predict SI Engine Efficiency and NOx Emissions,” SAE Technical Paper 790291, 1979, doi:10.4271/790291.