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Quantitative Measurements of Residual and Fresh Charge Mixing in a Modern SI Engine Using Spontaneous Raman Scattering
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 01, 1999 by SAE International in United States
Annotation ability available
Line-imaging of Raman scattered light is used to simultaneously measure the mole fractions of CO2, H2O, N2, O2, and fuel (premixed C3H8) in a modern 4-valve spark-ignition engine operating at idle. The measurement volume consists of 16 adjacent sub-volumes, each 0.27 mm in diameter × 0.91 mm long, giving a total measurement length of 14.56 mm. Measurements are made 3 mm under the centrally-located spark plug, offset 3 mm from the spark plug center towards the exhaust valves. Data are taken in 15 crank angle degree increments starting from top center before the intake stroke (-360 CAD) through top center of the compression stroke (0 CAD). Ensemble-averaged measurements obtained over 200 cycles provide data on the mean level of mixing between fresh charge and combustion residuals, and sets of 500 single-shot, cycle-resolved measurements provide statistics of charge composition fluctuations in the vicinity of the spark plug and permit resolution of mixing scales through analysis of the spatial covariance.
Single-shot data are analyzed over the middle 12 locations (∼11 mm length), where signal levels are high and noise interference is minimal. The statistical cycle-to-cycle variance in the residual mole fraction is observed to be highest at points where the mean spatial and temporal gradients in residual are large as determined from the cycle-averaged data. At time of spark (-15 CAD), however, rms fluctuations in the residual are less than 1%. Analysis of the spatial covariance functions permits assessment of the noise contribution to the measured mole fractions. These spatial correlations also indicate that there are large mixing length scales (∼ a centimeter or more) early in the intake stroke and at bottom center (-180 CAD). The mixing scales decay as the piston compresses the charge, to 2-4 millimeters at time of spark. Thus, the data presented indicate that, at idle, mixing between fresh charge and residuals is not complete at time of spark, though the level of fluctuation in gas composition is small.
CitationHinze, P. and Miles, P., "Quantitative Measurements of Residual and Fresh Charge Mixing in a Modern SI Engine Using Spontaneous Raman Scattering," SAE Technical Paper 1999-01-1106, 1999, https://doi.org/10.4271/1999-01-1106.
In-Cylinder Velocity Measurements, Combustion, and Flow Diagnostics
Number: SP-1446 ; Published: 1999-03-01
Number: SP-1446 ; Published: 1999-03-01
- Young, M.B., “Cyclic Dispersion in the Homogeneous-Charge Spark-Ignition Engine-A Literature Survey,” SAE Paper 810020, 1981.
- Ozdor, N., Dulger, M., and Sher, E., “Cyclic Variability in Spark Ignition Engines-A Literature Survey,” SAE Paper 940987, 1994.
- Alkidas, A., “The Effects of Fuel Preparation on Hydrocarbon Emissions of a S.I. Engine Operating Under Steady-State Conditions,” SAE Paper 941959, 1994.
- Carabateas, N. E., Taylor, A. M. K. P., Whitelaw, J. H., Ishii, K., Yoshida, K., and Matsuki, M., “The Effect of Injector and Intake Port Design on In-Cylinder Fuel Droplet Distribution, Airflow and Lean-Burn Performance for a Honda VTEC-E Engine,” SAE Paper 961923, 1996.
- Sztenderowicz, M.L. and Heywood, J.B., “Mixture Nonuniformity Effects on S.I. Engine Combustion Variability,’ SAE Paper 902142, 1990.
- Hinze, P.C. and Cheng, W.C., “Assessing the Factors Affecting SI Engine Cycle-to-Cycle Variations at Idle,” The 27th Symposium (International) on Combustion, The Combustion Institute, 1998.
- Matsuoka, S., Yamaguchi, T., and Umemura, Y., “Factors Influencing the Cyclic Variations of Combustion of Spark-Ignition Engine,” SAE Paper 710586, 1971.
- Yamada, T., Inoue, T., Yoshimatsu, A., Hiramatsu, T., and Konishi, M., “In-Cylinder Gas Motion of Multivalve Engine-Three Dimensional Numerical Simulation,” SAE Paper 860465, 1986.
- Ahmadi-Befrui, B., Brandstätter, W., Kratochwill, H., and Troger, C., “The Influence of Inlet Port Design on the In-Cylinder Charge Mixing,” SAE Paper 890842, 1989.
- Duclos, J. M., Bruneaux, G., and Baritaud, T. A., “3D Modeling of Combustion and Pollutants in a 4-valve SI Engine; Effect of Fuel and Residuals Distribution and Spark Location,” SAE Paper 961964, 1996.
- Bauer, W., Heywood, J.B., Avanessian, O., and Chu, D., “Flow Characteristics in Intake Port of Spark-Ignition Engine Investigated by CFD and Transient Gas Temperature Measurement,” SAE Paper 961997, 1996.
- Kosaka, H. and Kamimoto, T., “Quantitative Measurement of Fuel Vapor Concentration in an Unsteady Evaporating Spray via a 2-D Mie-Scattering Imaging Technique,” SAE Paper 932653, 1993.
- Espey, C., Dec, J.E., Litzinger, T.A., and Santavicca, D.A., “Quantitative 2-D Fuel Vapor Concentration Imaging in a Firing D.I. Diesel Engine Using Planar Laser-Induced Rayleigh Scattering,” SAE Paper 940682, 1994.
- Nakada, T., Itoh, T., and Takagi, Y., “CARS Measurement of the Unburned Gas Temperature Under Knocking and Non-Knocking Operation and Residual Mass Fraction Variation in a Spark Ignition Engine,” JSAE 928454, 1992.
- Lebel, M. and Cottereau, M.J., “Study of the Effect of Residual Gas Fraction on Combustion in a S.I. Engine Using Simultaneous CARS Measurements of Temperature and CO2 Concentration,” SAE Paper 922388, 1992.
- Baritaud, T. A. and Heinze, T. A., “Gasoline distribution measurements with PLIF in a SI engine,” SAE Paper 922355, 1992.
- Johansson, B., Neij, H., Alden, M., and Juhlin, G., “Investigations of the Influence of Mixture Preparation on Cyclic Variations in a SI-engine, Using Laser Induced Fluorescence,” SAE Paper 950108, 1995.
- Zhao, F., Taketomi, M., Nishida, K., and Hiroyasu, H., “PLIF Measurements of the Cyclic Variation of Mixture Concentration in a SI Engine,” SAE Paper 940988, 1994.
- Deschamps, B. and Baritaud, T., “Visualization of Gasoline and Exhaust Gases Distribution in a 4-valve SI Engine; Effects of Stratification on Combustion and Pollutants,” SAE Paper 961928, 1996.
- Grünefeld, G., Beushausen, V., Andersen, 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 Paper 941880, 1994.
- Grünefeld, G., Knapp, M., Beushausen, V., Andresen, P., Hentschel, W., and Manz, P., “In-Cylinder Measurements and Analysis on Fundamental Cold Start and Warm-Up Phenomena of SI Engines,” SAE Paper 952394, 1995.
- Miles, P., and Dilligan, M., “Quantitative In-Cylinder Fluid Composition Measurements Using Broadband Spontaneous Raman Scattering,” SAE Paper 960828, 1996.
- Knapp, M., Beushausen, V., Hentschel, W., Manz, P., Grünefeld, G., and Andresen, P., “In-Cylinder Mixture Formation Analysis with Spontaneous Raman Scattering Applied to a Mass Production SI Engine,” SAE Paper 970827, 1997.
- Miles, P. C. and Hinze, P. C., “Characterization of the Mixing of Fresh Charge with Combustion Residuals Using Laser Raman Scattering with Broadband Detection,” SAE Paper 981428, 1998.
- Miles, P., “Raman Line-Imaging for Spatially- and Temporally-Resolved Mole Fraction Measurements in Internal Combustion Engines,” Applied Optics, 1998, in press.
- Eckbreth, A.C., Laser Diagnostics for Combustion Temperature and Species, Abacus Press, 1988.
- Demtröder, W., Laser Spectroscopy, Springer,1996.