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Efficient Post-Processing Method for Identification of Local Hotspots in 3D CFD Simulations
Technical Paper
2022-37-0005
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Knocking is one of today’s main limitations in the ongoing efforts to increase efficiency and reduce emissions of spark-ignition engines. Especially for synthetic fuels or any alternative fuel type in general with a much steeper increase of the knock frequency at the KLSA, such as hydrogen, precise knock prediction is crucial to exploit their full potential. This paper therefore proposes a post-processing tool enabling further investigations to continuously gain better understanding of the knocking phenomenon. In this context, evaluation of local auto-ignitions preceding knock is crucial to improve knowledge about the stochastic occurrence of knock but also identify critical engine design to further optimize the geometry. In contrast to 0D simulations, 3D CFD simulations provide the possibility to investigate local parameters in the cylinder during the combustion. Measurement of auto-ignition yields challenges regarding the small time frame of the phenomenon and the required optical access to the combustion chamber. However, manual identification of auto-igniting hotspots within 3D CFD simulations is extremely time-consuming and not reasonable if a multitude of engine cycles or operating conditions have to be evaluated. This paper, therefore, introduces a post-processing method that allows automated identification of auto-igniting areas named hotspots. The method is developed based on LES data of 100 engine cycles at a single operating point and uses a geometrical comparison of the propagating flame front at different times to distinguish cells of a hotspot from the spark-ignited flame front. Two calibration parameters allow tuning of the method to make it applicable for various engines. The results show reliable identification of auto-igniting hotspots. The proposed method consequently provides an efficient tool for the investigation of local parameters related to auto-ignition that helps to improve understanding of the knocking phenomenon and consequently improves the engine development process.
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Fajt, N., Bargende, M., Kulzer, A., and Grill, M., "Efficient Post-Processing Method for Identification of Local Hotspots in 3D CFD Simulations," SAE Technical Paper 2022-37-0005, 2022, https://doi.org/10.4271/2022-37-0005.Also In
References
- Schießl , R. , Schubert , A. , and Maas , U. Temperature Fluctuations in the Unburned Mixture: Indirect Visualization Based on LIF and Numerical Simulations SAE Technical Paper 2006-01-3338 2006 10.4271/2006-01-3338
- Kleinschmidt , W. Selbstzündung im Klopfgrenzbereich von Serienmotoren Klopfregelung für Ottomotoren II 2006 1 21 978-3816926740
- Fandakov , A. , Grill , M. , Bargende , M. Kulzer , A.C.
- Hess , M. , Grill , M. , Bargende , M. , and Kulzer , A. Knock Model Covering Thermodynamic and Chemical Influences on the Two-Stage Auto-Ignition of Gasoline Fuels SAE Technical Paper 2021-01-0381 2021 10.4271/2021-01-0381
- Grill , M. , Billinger , T. , and Bargende , M. Quasi-Dimensional Modeling of Spark Ignition Engine Combustion with Variable Valve Train SAE Technical Paper 2006-01-1107 2006 10.4271/2006-01-1107
- Grill , M. and Bargende , M. The Development of an Highly Modular Designed Zero-Dimensional Engine Process Calculation Code SAE Int. J. Engines 3 1 2010 1 11 10.4271/2010-01-0149
- Netzer , C. 2019
- Netzer , C. , Seidel , L. , Pasternak , M. , Lehtiniemi , H. et al. Three-Dimensional Computational Fluid Dynamics Engine Knock Prediction and Evaluation Based on Detailed Chemistry and Detonation Theory International Journal of Engine Research 19 1 2018 33 44 10.1177/1468087417740271
- Bradley , D. , Morley , C. , Gu , X.J. , and Emerson , D.R. Amplified Pressure Waves During Autoignition: Relevance to CAI Engines SAE Technical Paper 2002-01-2868 2002 10.4271/2002-01-2868
- Robert , A. , Richard , S. , Colin , O. , and Poinsot , T. LES Study of Deflagration to Detonation Mechanisms in a Downsized Spark Ignition Engine Combustion and Flame 162 2015 2788 2807 10.1016/j.combustflame.2015.04.010
- Worret , R. , Bernhardt , S. , Schwarz , F. , and Spicher , U. Application of Different Cylinder Pressure Based Knock Detection Methods in Spark Ignition Engines SAE Technical Paper 2002-01-1668 2002 10.4271/2002-01-1668
- Douaud , A. and Eyzat , P. Four-Octane-Number Method for Predicting the Anti-Knock Behavior of Fuels and Engines SAE Technical Paper 780080 1978 10.4271/780080
- Livengood , J.C. and Wu , P.C. Correlation of Autoignition Phenomena in Internal Combustion Engines and Rapid Compression Machines Symposium (International) on Combustion 5 1 1955 347 356 10.1016/S0082-0784(55)80047-1
- Liang , L. , Reitz , R. , Iyer , C. , and Yi , J. Modeling Knock in Spark-Ignition Engines Using a G-equation Combustion Model Incorporating Detailed Chemical Kinetics SAE Technical Paper 2007-01-0165 2007 10.4271/2007-01-0165
- Linse , D. , Kleemann , A. , and Hasse , C. Probability Density Function Approach Coupled with Detailed Chemical Kinetics for the Prediction of Knock in Turbocharged Direct Injection Spark Ignition Engines Combust Flame 161 4 2014 997 1014 10.1016/j.combustflame.2013.10.025
- Pomraning , E. , Richards , K. , and Senecal , P. Modeling Turbulent Combustion Using a RANS Model, Detailed Chemistry, and Adaptive Mesh Refinement SAE Technical Paper 2014-01-1116 2014 10.4271/2014-01-1116
- Wang , Z. , Wang , Y. , and Reitz , R.D. Pressure Oscillation and Chemical Kinetics Coupling during Knock Processes in Gasoline Engine Combustion Energy & Fuels 26 12 2012 7107 7119 10.1021/ef301472g
- Blomberg , M. , Fajt , N. , and Leyens , L. 2022
- Blomberg , M. , Hess , M. , Hesse , R. , and Morsch , P. 2021