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Advanced SCR Flow Modeling with a Validated Large Eddy Simulation
Technical Paper
2015-01-1046
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
One promising application in the emission control is the Selective Catalytic Reduction (SCR) system for the reduction of nitric oxides from exhaust emissions. Previous works at the institute have highlighted the importance of accurate CFD turbulence modeling with respect to the turbulent mixing of ammonia vapor [1]. With the help of Laser Doppler Anemometry (LDA) measurements it was confirmed that RANS approaches are capable of predicting the velocity field adequately. In contrast, the turbulence level was underestimated for all RANS approaches [2].
Based on this work the paper at hand presents CFD results using Large Eddy Simulation (LES). The sensitivity of the solution with respect to spatial and temporal resolution as well as the boundary conditions is demonstrated. In accordance with the Kolmogorov theory grid sizes ranging from 3.2 to 20 million cells were investigated using LES methodology. The representation of the velocity field was found to be accurate independent of the mesh size. The simulation results are compared with the measured spatial velocity vectors and Reynolds stress tensors. In general, all LES calculations are in good agreement with the measured Turbulent Kinetic Energy (TKE) data. The prediction of the TKE was improved significantly compared to the RANS calculations. The applicability of the LES methodology is shown for cold and hot operating conditions.
Therefore it can be concluded that it is a promising approach to improve the accuracy of the scalar mixing process. Further work will concentrate on the implementation and validation of the liquid phase dynamics.
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Zöchbauer, M., Smith, H., and Lauer, T., "Advanced SCR Flow Modeling with a Validated Large Eddy Simulation," SAE Technical Paper 2015-01-1046, 2015, https://doi.org/10.4271/2015-01-1046.Also In
References
- Fischer , S. , Bitto , R. , Lauer , T. , Krenn , C. et al. Impact of the Turbulence Model and Numerical Approach on the Prediction of the Ammonia Homogenization in an Automotive SCR System SAE Int. J. Engines 5 3 1443 1458 2012 10.4271/2012-01-1291
- Zöchbauer , M. , Fischer , S. , Lauer , T. , Siegmann-Hegerfeld , T. et al. Validation of Turbulence Models for an Automotive SCR System with Laser Doppler Anemometry Measurements SAE Technical Paper 2013-01-1579 2013 10.4271/2013-01-1579
- Abu-Ramadan , E. , Saha , K. , and Li , X. Modeling of the Injection and Decomposition Processes of Urea-Water-Solution Spray in Automotive SCR Systems SAE Technical Paper 2011-01-1317 2011 10.4271/2011-01-1317
- Zheng , G. , Wang , F. , Zhang , S. , Zhang , J. et al. Development of Compact SCR Systems with Closely Coupled Injector Configurations SAE Technical Paper 2014-01-1546 2014 10.4271/2014-01-1546
- El-Tahry , S.H A Comparison of Three Turbulence Models in Engine-Like Geometries International Symposium on Diagnostics and Modelling of Combustion in Reciprocating Engines 203 213 Commodia 1985
- Tominaga , Y. and Stathopoulos , T. Turbulent Schmidtnumbers for CFD analysis with various types of flowfield Atmospheric Environment 41 8091 8099 2007
- Ström , H. , Lundström , A. and Andersson , B. Choice of urea-spray models in CFD simulations of urea-SCR systems Chemical Engineering Journal 150 69 82 2009
- Fischer , S. and Lauer , T. Urea Injection in Diesel applications: Multiphase multicomponent modeling using STAR-CD STAR European Conference London 2010 http://www.cd-adapco.com/pdfs/presentations/eu10/IFA.pdf
- Pope , S.B Turbulent Flows - Models and Physics Cambridge University Press Cambridge 2000 978-0-521-59886-6
- CD-adapco User Guide STAR-CCM+ Version 9.02 2014
- Fröhlich , J. Large Eddy Simulation turbulenter Strömungen Springer Berlin 2006 978
- Fontanesi , S. , Paltrinieri , S. , and Cantore , G. LES Analysis of Cyclic Variability in a GDI Engine SAE Technical Paper 2014-01-1148 2014 10.4271/2014-01-1148
- Hinze , J.O Turbulence McGraw-Hill 1959
- Ferzinger , J. , Peric , M. Computational Methods for Fluid Dynamics Springer London 3rd 2002 3540420746
- Lecheler , S. Numerische Strömungsberechnung Vieweg +Teubner Wiesbaden 2009
- Jasak , H. Error Analysis and Estimation for the Finite Volume Method with Applications to Fluid Flows PHD Thesis Imperial College London 1996
- Andersson , B. , Andersson , R. , Hakansson , L. , Mortensen , M. , Sudiyo , R. , van Wachem , B. Computational Fluid Dynamics for Engineers Cambridge University Press 2011
- VDI-Gesellschaft Verfahrenstechnik und Chemieingenieurwesen VDI-Wärmeatlas Springer 2006
- Tennekes , H. , Lumley , J. A first Course in Turbulence MIT Press 1972
- Vienna Scientific Cluster Der Vienna Scietific Cluster - HighPerformance Computing in Österreich www.vsc.ac.at Oct. 2014
- Lumley , J.L , and Newman , G. The return to isotropy of homogeneous turbulence Journal of Fluid Mechanics 82 161 178 1977
- Radenkovic , D.R , Burazer , J.M , Novkovic , D.M Anisotropy Analysis of Turbulent Swirl Flow FME Transactions 2014 42 19 25 2014
- Jovicic , N. , Breuer , M. , Jovanovic , J. Anisotropy-Invariant Mapping of Turbulence in a Flow Past an Unswept Airfoil at High Angle of Attack Journal of Fluids Engineering 128 559 567 2006
- Ivanova , E. Numerical simulation of turbulent mixing in complex flows Ph.D. thesis Stuttgart University, Institut für Verbrennungstechnik 2012
- Tominaga , Y. , Stathopoulos , T. CFD modeling of pollution dispersion in a street canyon: Comparison between LES and RANS Journal of Wind Engineering and Industrial Aerodynamics 99 340 348 2011
- Schlichting , H. and Gersten , K. Boundary-Layer Theory MacGraw-Hill 2000
- Smith , H. , Zöchbauer , M. , and Lauer , T. Advanced Spray Impingement Modelling for an Improved Prediction Accuracy of the Ammonia Homogenisation in SCR systems SAE Technical Paper 2015-01-1054 2015 10.4271/2015-01-1054