This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Effect of Temperature Stratification on the Auto-ignition of Lean Ethanol/Air Mixture in HCCI engine
Technical Paper
2008-01-1669
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
It has been known from multi-zone simulations that HCCI combustion can be significantly affected by temperature stratification of the in-cylinder gas. With the same combustion timing (i.e. crank angles at 50% heat release, denoted as CA50), large temperature stratification tends to prolong the combustion duration and lower down the in-cylinder pressure-rise-rate. With low pressure-rise-rate HCCI engines can be operated at high load, therefore it is of practical importance to look into more details about how temperature stratification affects the auto-ignition process. It has been realized that multi-zone simulations can not account for the effects of spatial structures of the stratified temperature field, i.e. how the size of the hot and cold spots in the temperature field could affect the auto-ignition process. This question is investigated in the present work by large eddy simulation (LES) method which is capable of resolving the in-cylinder turbulence field in space and time. The initial temperature field for LES is presumed as the superimposition of a mean temperature and a sine-function fluctuating temperature. The engine runs on ethanol with a relative air/fuel ratio of 3.3. The LES results show that the initial shape of hot/cold spots is quickly modified by turbulence. A particular hot/cold spot size on the order of large eddy integral scale is found at which the combustion duration tends to be shorter. This reveals the fact that not only the magnitude of the temperature stratification but also the spatial structure of the stratification could affect the auto-ignition process.
Recommended Content
Authors
Citation
Yu, R., Joelsson, T., Bai, X., and Johansson, B., "Effect of Temperature Stratification on the Auto-ignition of Lean Ethanol/Air Mixture in HCCI engine," SAE Technical Paper 2008-01-1669, 2008, https://doi.org/10.4271/2008-01-1669.Also In
References
- Homogeneous Charge Compression Ignition (HCCI) 978-0-7680-1478-5
- Assanis Dennis N. Najt Paul M. Dec John E. Eng James A. Asmus Thomas N. Zhao Fuquan Homogeneous Charge Compression Ignition (HCCI) Engines 978-0-7680-1123-4
- Christensen, M. Johansson, B. “The effect of in-cylinder flow and turbulence on HCCI operation” SAE 2002-01-2864
- Christensen, M. Johansson, B. Hultqvist, A. “The effect of combustion chamber geometry on HCCI operation” SAE 2002-01-0425
- Vressner, A. Hultqvist, A. Johansson, B. “Study on Combustion Chamber Geometry Effects in an HCCI Engine using High-Speed Cycle-Resolved Chemiluminescence Imaging” SAE 2007-01-0217
- Seyfried, H. Olofsson, J. Sjöholm, J. Richter, M. Aldén M. Vressner, A. Hultqvist, B. Johansson, B. “High-Speed PLIF Imaging for Investigation of Turbulence on Heat Release Rates in HCCI Combustion” SAE 2007-01-0213
- Kong, S.C. Reitz, R.D. Christensen, M. Johansson, B. “Modeling the effect of geometry generated turbulence on HCCI engine combustion” SAE 2003-01-1088
- Aceves, S.M. Flowers, D.L. Martinez-Frias, J. Espinosa-Loza, F. Christensen, M. Johansson, B. Hessel, R.P. “Analysis of the effect of geometry generated turbulence on HCCI combustion by multi-zone modeling” SAE 2005-01-2134
- Yu, R. X. Bai, X. S Vressner, A. Hultqvist, A. Johansson, B. Olofsson, J. Seyfried, H. Sjöholm, J. Richter, M. Aldén, M. “Effect of Turbulence on HCCI Combustion” SAE 2007-01-0183
- Joelsson, T. Yu, R. X. Bai, X. S Vressner, A. Johansson, B. “Large eddy simulation and experiments of the auto-ignition process of lean ethanol/air mixture in HCCI engines” 2008
- Chen J.H. Hawkes E.R. Sankaran, R. Mason, S.D. Im. H.G. Combust. Flames 145 2006 128 144
- Sankaran R. Im H.G. Combust. Theory Modelling 9 3 2005 417 432
- Sjöberg M. Dec J.E. Cernansky N.P. Potential of thermal stratification and combustion retard for reducing pressure-rise rates in HCCI engines, based on multi-zone modeling and experiments SAE paper 2005-01-0113
- Aceves, S.M. Flowers, D.L. Espinosa-Loza, F. Martinez-Frias, J. Dibble, R.W. Christensen, M. Johansson, B. Hessel, R.P. “Piston-liner crevice geometry effect on HCCI combustion by multi-zone modeling” SAE 2002-01-2869
- Aceves, S.M. Flowers, D.L. Espinosa-Loza, F. Martinez-Frias Dec, J.E. Sjöberg, M. Dibble, R.W. Hessel, R.P. “Spatial analysis of the emission sources for HCCI combustion at low loads using a multi-zone model” SAE 2004-01-1910
- Yu, R. Bai, X.S. Lehtiniemi, H. Ahmed, S. S. Mauss, F. Richter, M. Aldén, M. Hildingsson, L. Johansson, B. Hultqvist, A. “Effect of Turbulence and Initial Temperature Inhomogeneity on Homogeneous Charge Compression Ignition Combustion” SAE 2006-01-3318
- Yu, R. Bai, X.S. Hildingsson, L. Hultqvist, A. Miles, P. “Numerical and experimental investigation of turbulent flows in a Diesel engine” SAE 06-01-3436
- Marinov, N. M “A Detailed Chemical Kinetic Model for High Temperature Ethanol Oxidation” Int. J. Chem. Kinet. 31 183 220 1999
- Seiser R. Humer S. Seshadri K. Pucher E. Experimental investigation of methanol and ethanol flames in nonuniform flows Proc. Combustion Inst. 31 1173 1180 2007
- Goodwin D.G. CANTERA: An open-source, object-oriented software suite for combustion http://www.nsf-combustion.umd.edu/pdf/goodwin_abstract.pdf 2007 12 10
- Lehtiniemi, H. Mauss, F. Balthasar, M. Magnusson, I. “Modeling diesel engine combustion with detailed chemistry using a progress variable approach” SAE 2005-01-3855
- Yu, R. Nogenmyr, K.-J. Bai, X.S. “LES of swirling turbulent methane/air flame” ECCOMAS thematic conference on computational combustion Lisbon June 21-24 2005
- Gullbrand, J. Bai, X. S. Fuchs, L. “High Order Cartesian Grid Method for Calculation of Incompressible Turbulent Flows” Int. J. of Numer. Methods in Fluids 36 687 709 2001
- Jeong, J. Hussain, F. “On the identification of a vortex” Journal of Fluid Mechanics 285 69 94 1995