Knock in spark-ignition engines: End-gas temperature measurements using rotational CARS and detailed kinetic calculations of the autoignition process

Cycle-resolved end-gas temperatures were measured using dual-broadband rotational CARS in a single-cylinder spark-ignition engine. Simultaneous cylinder pressure measurements were used as an indicator for knock and as input data to numerical calculations. The chemical processes in the end-gas have been analysed with a detailed kinetic mechanism for mixtures of iso-octane and n-heptane at different Research Octane Numbers (RON'S). The end-gas is modelled as a homogeneous reactor that is compressed or expanded by the piston movement and the flame propagation in the cylinder. The calculated temperatures are in agreement with the temperatures evaluated from CARS measurements. It is found that calculations with different RON'S of the fuel lead to different levels of radical concentrations in the end-gas. The apperance of the first stage of the autoignition process is marginally influenced by the RON, while the ignition delay of the second stage is increased with increasing RON. © 1997 Society of Automotive Engineers, Inc. (Less)

[1]  Ingemar Denbratt,et al.  Comparison of Cylinder Pressure Based Knock Detection Methods , 1997 .

[2]  A. Leipertz,et al.  Experimental comparison of single-shot broadband vibrational and dual-broadband pure rotational coherent anti-Stokes Raman scattering in hot air. , 1996, Applied optics.

[3]  M. Nakano,et al.  Predictions of the Knock Onset and the Effects of Heat Release Pattern and Unburned Gas Temperature on Torque at Knock Limit in S.I. Engines , 1995 .

[4]  C. R. McDonald,et al.  Studies of Knock in a Spark Ignition Engine with “CARS” Temperature Measurements and Using Different Fuels , 1995 .

[5]  S. Kröll,et al.  A test of different rotational Raman linewidth models: Accuracy of rotational coherent anti-Stokes Raman scattering thermometry in nitrogen from 295 to 1850 K , 1993 .

[6]  Paulius V. Puzinauskas,et al.  Examination of Methods Used to Characterize Engine Knock , 1992 .

[7]  S. Kröll,et al.  Is rotational CARS an alternative to vibrational CARS for thermometry? , 1990 .

[8]  John B. Heywood,et al.  Characterization of Knock in a Spark-Ignition Engine , 1989 .

[9]  C. R. Ferguson,et al.  Unburned Gas Temperatures in an Internal Combustion Engine. I:Cars Temperature Measurements , 1987 .

[10]  M. Cottereau,et al.  Single-Shot Temperature Measurements by Cars in an I.C. Engine for Normal and Knocking Conditions , 1987 .

[11]  M. Aldén,et al.  Rotational CARS generation through a multiple four-color interaction. , 1986, Applied optics.

[12]  A. Eckbreth,et al.  Simultaneous rotational coherent anti-Stokes Raman spectroscopy and coherent Stokes Raman spectroscopy with arbitrary pump-Stokes spectral separation. , 1986, Optics letters.

[13]  W. Leppard,et al.  Individual-Cylinder Knock Occurence and Intensity in Multicylinder Engines , 1982 .

[14]  A. Eckbreth,et al.  Pressure-induced narrowing of the cars spectrum of N2☆ , 1980 .

[15]  Alan C. Eckbreth,et al.  BOXCARS: Crossed‐beam phase‐matched CARS generation in gases , 1978 .

[16]  D. Bradley,et al.  Heat release rates due to autoignition, and their relationship to knock intensity in spark ignition engines , 1996 .

[17]  F. Behrendt,et al.  Time-resolved investigation of hot spots in the end gas of an S. I. engine by means of 2-D double-pulse lif of formaldehyde , 1996 .

[18]  P. Gaffuri,et al.  Autoignition chemistry in a motored engine: An experimental and kinetic modeling study , 1996 .

[19]  A. Eckbreth.  Laser Diagnostics for Temperature and Species in Unsteady Combustion , 1996 .

[20]  M. Aldén,et al.  Oxygen concentration and temperature measurements in N2–O2 mixtures using rotational coherent anti-Stokes Raman spectroscopy , 1996 .

[21]  J. Warnatz,et al.  Detection of hot spots in the end gas of an internal combustion engine using two-dimensional lif of formaldehyde , 1994 .

[22]  R. R. Maly,et al.  State of the art and future needs in S.I. engine combustion , 1994 .

[23]  B. Johansson,et al.  Dual-broadband rotational cars measurements in an IC engine , 1994 .

[24]  G. Kalghatgi,et al.  Cars temperature measurements and the cyclic dispersion of knock in spark ignition engines , 1994 .

[25]  Charles K. Westbrook,et al.  Hydrocarbon ignition: Automatic generation of reaction mechanisms and applications to modeling of engine knock , 1992 .

[26]  Jürgen Warnatz,et al.  A detailed chemical kinetic reaction mechanism for the oxidation of iso-octane and n-heptane over an extended temperature range and its application to analysis of engine knock , 1989 .

[27]  A. Eckbreth.  Laser Diagnostics for Combustion Temperature and Species , 1988 .

[28]  John B. Heywood,et al.  Internal combustion engine fundamentals , 1988 .

[29]  Rowland S. Benson.  Chapter 6 – Heat Transfer in Engines , 1979 .

[30]  C. Walcutt,et al.  End-Gas Temperature-Pressure Histories and Their Relation To Knock , 1961 .