This content is not included in your SAE MOBILUS subscription, or you are not logged in.
LES Analysis of Cyclic Variability in a GDI Engine
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 01, 2014 by SAE International in United States
Annotation ability available
The paper critically discusses Large-Eddy Simulation (LES) potential to investigate cycle-to-cycle variability (CCV) in internal combustion engines. Particularly, the full load/peak power engine speed operation of a high-performance turbocharged GDI unit, for which ample cycle-to-cycle fluctuations were observed during experimental investigations at the engine test bed, is analyzed through a multi-cycle approach covering 25 subsequent engine cycles. In order to assess the applicability of LES within the research and development industrial practice, a modeling framework with a limited impact on the computational cost of the simulations is set up, with particular reference to the extent of the computational domain, the computational grid size, the choice of boundary conditions and numerical sub-models [1, 2, 3]. In order to evaluate the applicability of the adopted approach to the resolution of an adequate portion of the overall turbulent energy spectrum, different grid metrics are at first introduced, based on criteria available in literature [4, 5]. A qualitative comparison between CFD results and experimental evidence is then carried out in terms of both in-cylinder pressure envelope and coefficients of variation for any of indicated mean effective pressure, 10%, 50% and 90% of fuel burnt distributions among the investigated cycles. Particularly, a detailed analysis of the physical factors influencing the exhibited cycle-to-cycle variability is performed through the use of correlation coefficients, aiming at highlighting possible hierarchies between the many involved phenomena and the observed engine behavior. Finally, a phase-dependent Proper Orthogonal Decomposition (POD). Particularly, while POD applications available in literature mainly cover vector fields and flow structures [6, 7], in the present paper the analysis is extended to scalar fields describing the combustion process evolution and its cyclic variability, and results are critically analyzed and commented.
CitationFontanesi, S., Paltrinieri, S., and Cantore, G., "LES Analysis of Cyclic Variability in a GDI Engine," SAE Technical Paper 2014-01-1148, 2014, https://doi.org/10.4271/2014-01-1148.
- Fontanesi, S., Paltrinieri, S., d'Adamo, A., Duranti, S., “Investigation of boundary condition effects on the analysis of cycle-to-cycle variability of a turbocharged GDI engine”, International Conference on LES for Internal Combustion Engine Flows, 2012
- Fontanesi, S., Paltrinieri, S., Tiberi, A., and D'Adamo, A., “LES Multi-cycle Analysis of a High Performance GDI Engine,” SAE Technical Paper 2013-01-1080, 2013, doi:10.4271/2013-01-1080.
- Fontanesi, S., Paltrinieri, S., D'Adamo, A., Cantore, G. et al., “Knock Tendency Prediction in a High Performance Engine Using LES and Tabulated Chemistry” SAE Int. J. Fuels Lubr. 6(1):2013, doi:10.4271/2013-01-1082.
- Pope, S. B., “Ten questions concerning the large-eddy simulation of turbulent flows”, Phys New J., Vol. 6 (35) doi:10.1088/1367-2630/6/1/035.
- Brusiani, F. and Bianchi, G., “LES Simulation of ICE Non- Reactive Flows in Fixed Grids,” SAE Technical Paper 2008-01-0959, 2008, doi:10.4271/2008-01-0959.
- Liu, K. and Haworth, D., “Development and Assessment of POD for Analysis of Turbulent Flow in Piston Engines,” SAE Technical Paper 2011-01-0830, 2011, doi:10.4271/2011-01-0830.
- Chen, H., Reuss, D. L., Hung, D. L. S., Sick, V., “A practical guide for using proper orthogonal decomposition in engine research,” International Journal of Engine Research doi:10.1177/1468087412455748.
- Heywood, J. B., “Internal Combustion Engine Fundamentals,”, McGraw Hill
- 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.
- Fontanesi, S., D'Adamo, A., Paltrinieri, S., Cantore, G. et al., “Assessment of the Potential of Proper Orthogonal Decomposition for the Analysis of Combustion CCV and Knock Tendency in a High Performance Engine,” SAE Technical Paper 2013-24-0031, 2013, doi:10.4271/2013- 24-0031.
- Richard S., Colin O., Vermorel O., Benkenida A., Angelberger C., Veynante D. “Towards large eddy simulation of combustion in spark ignition engines” Proceedings of the Combustion Institute 31 (2007) 3059-3066.
- Pope, S. B. “Turbulent flows” Cambridge university press, 2000
- Bizon, K., Continillo, G., Leistner, K. C., Mancaruso, E, Vaglieco, B. M., “POD-based analysis of cycle-to-cycle variations in an optically accessible diesel engine,” Proceedings of the Combustion Institute 32 (2009) 2809-2816
- Fontanesi S., Giacopini M., “Multiphase CFD-CHT optimization of the cooling jacket and FEM analysis of the engine head of a V6 diesel engine”, Applied Thermal Engineering, Volume 52, Issue 2, 15 April 2013, Pages 293-303, ISSN 1359-4311, doi:10.1016/j.applthermaleng.2012.12.005.
- Fontanesi, S., Cicalese, G., and Tiberi, A., “Combined In- cylinder / CHT Analyses for the Accurate Estimation of the Thermal Flow Field of a High Performance Engine for Sport Car Applications,” SAE Technical Paper 2013-01-1088, 2013, doi:10.4271/2013-01-1088.
- Fontanesi S., Cicalese G., d'Adamo A., Cantore G., “A Methodology To Improve Knock Tendency Prediction In High Performance Engines”, Energy Procedia 00 (2013) 060-12261