Application of an entrainment turbulent combustion model with validation based on the distribution of chemical species in an optical spark ignition engine

Internal combustion engines are still the energy conversion units of choice in transport and distributed energy generation. Due to the fuel mix, spark ignition (SI) engines represent a viable solution that features improved fuel flexibility with respect to their compression ignition counterparts. Therefore, manufacturers are continuously trying to increase their performance and reduce emissions through experimental and numerical investigations. A growing trend in engine improvement is the application of simulations on a wider scale in order to contain development costs. Combustion is the most complex part of the working cycle and for SI power units, modeling flame propagation represents an essential feature of predictive numerical investigations. Within this context, the present study was aimed at better understanding the mass transfer between unburned and reacting gas, as well as characteristic reaction time scales within the reaction zone. A 0D model with three zones was applied for different engine speed, load, air-fuel ratio and spark timing settings, chosen as representative for mid-road load automotive use. Combined in-cylinder pressure measurements and flame imaging were used for validating the essential concept of fresh charge entrainment and burn-up process. One major conclusion of the work was that there is a definite stratification of chemical species within the burned-reacting gas that can be well captured by the entrainment model. The fact that the calibration coefficients require different values for accurate prediction of the pressure traces during flame propagation, emphasizes the complexity of the combustion process, as well as the limitations of considering flames as laminar even at local scale. The study also identified the scale at which mass transfer takes place as an essential factor for correct turbulent combustion modeling.

[1]  Josef Kittler,et al.  On threshold selection using clustering criteria , 1985, IEEE Transactions on Systems, Man, and Cybernetics.

[2]  Gerardo Valentino,et al.  In - cylinder OH and CO2* detection in SI engine through UV natural emission spectroscopy , 2015 .

[3]  Gerardo Valentino,et al.  Combustion Process Analysis in a DISI Engine Fuelled with N-Butanol through UV-VIS Emission Spectroscopy , 2015 .

[4]  P. Aleiferis,et al.  Characterisation of flame development with ethanol, butanol, iso-octane, gasoline and methane in a direct-injection spark-ignition engine , 2013 .

[5]  Sebastian Verhelst,et al.  Multi-zone thermodynamic modelling of spark-ignition engine combustion -An overview , 2009 .

[6]  Shijin Shuai,et al.  Ultra-high speed imaging and OH-LIF study of DMF and MF combustion in a DISI optical engine , 2014 .

[7]  Jim R. Parker,et al.  Algorithms for image processing and computer vision , 1996 .

[8]  Fabio Bozza,et al.  Hierarchical 1D/3D Approach for the Development of a Turbulent Combustion Model Applied to a VVA Turbocharged Engine. Part I: Turbulence Model , 2014 .

[9]  P. Aleiferis,et al.  The nature of early flame development in a lean-burn stratified-charge spark-ignition engine , 2004 .

[10]  Adrian Irimescu.  Working Fluid Properties Variation During Combustion in Premixed Charge Hydrogen Engines , 2012 .

[11]  K. A. Subramanian,et al.  Experimental investigation and phenomenological model development of flame kernel growth rate in a gasoline fuelled spark ignition engine , 2015 .

[12]  Simona Silvia Merola,et al.  Spectroscopic Investigations and High Resolution Visualization of the Combustion Phenomena in a Boosted PFI SI Engine , 2009 .

[13]  Katsunori Ueda,et al.  MIXING CONTROL STRATEGY FOR ENGINE PERFORMANCE IMPROVEMENT IN A GASOLINE DIRECT-INJECTION ENGINE , 1998 .

[14]  Milan Sonka,et al.  Image Processing, Analysis and Machine Vision , 1993, Springer US.

[15]  Adrian Irimescu,et al.  Compression ratio and blow-by rates estimation based on motored pressure trace analysis for an optical spark ignition engine , 2013 .

[16]  Yuji Ikeda,et al.  Basic aspects of OH(A), CH(A), and C2(d) chemiluminescence in the reaction zone of laminar methane–air premixed flames , 2005 .

[17]  Anil K. Jain,et al.  Algorithms for Clustering Data , 1988 .

[18]  Kexin Liu,et al.  Turbulent flame and mass burning rate in a spark ignition engine , 2013 .

[19]  Denis Veynante,et al.  Simulation of CO and NO emissions in a SI engine using a 0D coherent flame model coupled with a tabulated chemistry approach , 2014 .

[20]  Lorenzo Galleani,et al.  In-cylinder pressure-based direct techniques and time frequency analysis for combustion diagnostics in IC engines , 2015 .

[21]  Yukiyasu Tanaka,et al.  A Study on Gasoline Engine Combustion by Observation of Intermediate Reactive Products during Combustion , 1979 .

[22]  M. Q. McQuay,et al.  Systematic measurements of OH chemiluminescence for fuel-lean, high-pressure, premixed, laminar flames , 2001 .

[23]  E. A. Aghdam,et al.  VALIDATION OF A BLOWBY MODEL USING EXPERIMENTAL RESULTS IN MOTORING CONDITION , 2010 .

[24]  Jihad Badra,et al.  A Simple Method to Predict Knock Using Toluene, N-Heptane and Iso-Octane Blends (TPRF) as Gasoline Surrogates , 2015 .

[25]  Hua Zhao,et al.  Turbulent flame boundary and structure detection in an optical DISI engine using tracer-based two-line PLIF technique , 2015 .

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

[27]  Frederick W. Williams,et al.  Chemiluminescence spectra from cool and blue flames: Electronically excited formaldehyde , 1973 .

[28]  B. Li,et al.  Analysis of in-cylinder H2O2 and HO2 distributions in an HCCI engine - Comparison of laser-diagnostic results with CFD and SRM simulations , 2015 .

[29]  C. Rakopoulos,et al.  CFD modeling and experimental study of combustion and nitric oxide emissions in hydrogen-fueled spark-ignition engine operating in a very wide range of EGR rates , 2012 .

[30]  George Kosmadakis,et al.  Computational fluid dynamics investigation of alternative nitric oxide emission mechanisms in a hydrogen-fueled spark-ignition engine , 2014 .

[31]  George Kosmadakis,et al.  Evaluation of a combustion model for the simulation of hydrogen spark-ignition engines using a CFD code , 2010 .

[32]  Gerardo Valentino,et al.  UV-visible Optical Characterization of the Early Combustion Stage in a DISI Engine Fuelled with Butanol-Gasoline Blend , 2013 .

[33]  Richard R. Steeper,et al.  Piston Wetting in an Optical DISI Engine: Fuel Films, Pool Fires, and Soot Generation , 2001 .

[34]  Gerardo Valentino,et al.  Development of a semi-empirical convective heat transfer correlation based on thermodynamic and optical measurements in a spark ignition engine , 2015 .

[35]  R. Reitz.  Directions in internal combustion engine research , 2013 .

[36]  G. Fontana,et al.  Experimental analysis of a spark-ignition engine using exhaust gas recycle at WOT operation , 2010 .

[37]  Gerardo Valentino,et al.  Evaluation of different methods for combined thermodynamic and optical analysis of combustion in spark ignition engines , 2014 .

[38]  Efthimios Zervas,et al.  Correlations between cycle-to-cycle variations and combustion parameters of a spark ignition engine , 2004 .

[39]  Fanhua Ma,et al.  A fractal-based quasi-dimensional combustion model for SI engines fuelled by hydrogen enriched compressed natural gas , 2012 .

[40]  P. G. Hill,et al.  The structure of small-scale turbulence and its effect on combustion in spark ignition engines , 1987 .

[41]  Sebastian Verhelst,et al.  Development and validation of a quasi-dimensional model for methanol and ethanol fueled SI engines , 2014 .

[42]  P. L. Curto-Risso,et al.  On cycle-to-cycle heat release variations in a simulated spark ignition heat engine , 2010, 1005.5410.

[43]  Andrew Lewis,et al.  Ultra Boost for Economy: Extending the Limits of Extreme Engine Downsizing , 2014 .

[44]  Paul J. Litke,et al.  Comparison of In-Cylinder Pressure Measurement Methods in a Small Spark Ignition Engine , 2014 .

[45]  Norbert Peters,et al.  Turbulent premixed combustion: A flamelet formulation and spectral analysis in theory and IC-engine experiments , 1992 .

[46]  Denis Veynante,et al.  Turbulent combustion modeling , 2002, VKI Lecture Series.

[47]  B. Thrush,et al.  Mechanism of chemiluminescent combination reactions involving oxygen atoms , 1962, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[48]  J. Keck,et al.  Turbulent flame propagation and combustion in spark ignition engines , 1983 .

[49]  Fabrice Foucher,et al.  Fractal approach to the evaluation of burning rates in the vicinity of the piston in a spark-ignition engine , 2005 .

[50]  Norbert Peters,et al.  Super-Knock Prediction Using a Refined Theory of Turbulence , 2013 .

[51]  G. T. Kalghatgi,et al.  WITHDRAWN: Developments in internal combustion engines and implications for combustion science and future transport fuels , 2014 .

[52]  Fred W. Bowditch,et al.  A New Tool for Combustion Research A Quartz Piston Engine , 1961 .

[53]  Joachim Demuynck,et al.  A correlation for the laminar burning velocity for use in hydrogen spark ignition engine simulation , 2011 .

[54]  Xue-Song Bai,et al.  Distributed reactions in highly turbulent premixed methane/air flames Part I. Flame structure characterization , 2015 .

[55]  R. M. Green,et al.  LIF and Flame-Emission Imaging of Liquid Fuel Films and Pool Fires in an SI Engine During a Simulated Cold Start , 1997 .

[56]  Gautam Kalghatgi,et al.  Pre-ignition and ‘super-knock’ in turbo-charged spark-ignition engines , 2012 .

[57]  Fokion N. Egolfopoulos,et al.  CO2* Chemiluminescence in Premixed Flames , 1995 .

[58]  Adrian Irimescu,et al.  COMPARISON OF COMBUSTION CHARACTERISTICS AND HEAT LOSS FOR GASOLINE AND METHANE FUELING OF A SPARK IGNITION ENGINE , 2013 .