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Development of a Numerical Methodology for the Assessment of Flow Noise in Complex Engine Exhaust Systems
Technical Paper
2021-01-1043
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Worldwide regulations concerning noise emissions of road vehicles are constantly demanding further reductions of acoustic emissions, which are considered a major environmental health concern in several countries. Among the different sources contributing to noise generation in vehicles equipped with internal combustion engines, exhaust flow noise is one of the most significant, being generated by turbulence development in the exhaust gases, and robust and reliable numerical methodologies for its prediction in early design phases are currently still needed. To this extent, Computational Aero-Acoustics (CAA) can be considered a valuable approach to characterize the physical mechanisms leading to flow noise generation and its propagation, and it could therefore be used to support exhaust system development prior to the execution of experimental testing campaigns.
This paper describes the development of a CAA methodology suitable for automotive applications that can be used to support the design of new exhaust system components in their early phases. In particular, the work focuses on the flow noise generated in a complex heavy-duty exhaust system, featuring three tailpipes located next to the ground. Firstly, the near-field acoustic field is obtained with a Direct Noise Computation (DNC) approach from an unsteady compressible 3D Computational Fluid Dynamics (3D-CFD) simulation, carried out by means of the commercially available 3D-CFD software STAR-CCM+. A Detached Eddy Simulation (DES) technique is implemented to reduce the high computational cost of the DNC approach and it has been initialized by a steady-state converged solution. The steady-state simulation has been also exploited to extract qualitative predictive indexes, as a preliminary characterization of the system in terms of mean flow and broadband noise generation.
Finally, predicted near-field noise levels are evaluated to obtain an assessment of engine exhaust system acoustic performance.
Authors
- Federico Millo - Politecnico di Torino
- Benedetta Peiretti Paradisi - Politecnico di Torino
- Renzo Arina - Politecnico di Torino
- Francesco Sapio - Politecnico di Torino
- Andrea Bianco - Powertech Engineering
- Antonio Benetti - CNH Industrial - Iveco - Medium Trucks
- Monica Moratti - CNH Industrial - Iveco - Medium Trucks
- Annalisa Reviglio - Cornaglia SpA
- Alessio Tarabocchia - Cornaglia SpA
- Andrea Bertoglio - Cornaglia SpA
Citation
Millo, F., Peiretti Paradisi, B., Arina, R., Sapio, F. et al., "Development of a Numerical Methodology for the Assessment of Flow Noise in Complex Engine Exhaust Systems," SAE Technical Paper 2021-01-1043, 2021, https://doi.org/10.4271/2021-01-1043.Also In
References
- Mishra , S. , Gummadi , N. , Bozzi , L. , Vaughn , N. et al. Computational Aeroacoustics of Mufflers for Exhaust Air Rush Prediction and Experimental Validation SAE Techical Paper 2017-01-1311 2017 https://doi.org/10.4271/2017-01-1311
- Schoder , S. and Kaltenbacher , M. Hybrid Aeroacoustic Computations: State of Art and New Achievements J. Theor. Comput. Acoust. 27 4 2019 10.1142/S2591728519500208
- Colonius , T. and Lele , S.K. Computational Aeroacoustics: Progress on Nonlinear Problems of Sound Generation Prog. Aerosp. Sci. 40 6 2004 345 416 10.1016/j.paerosci.2004.09.001
- Lighthill , M. On Sound Generated Aerodynamically I. General Theory Proc. R. Soc. London. Ser. A. Math. Phys. Sci. 211 1107 1952 564 587 10.1098/rspa.1952.0060
- Powell , R.E. , Hendriana , D. , Gutzeit , B. , Golsch , K. et al. Direct Aeroacoustic Simulation of Flow Impingement Noise in an Exhaust Opening SAE Techical Paper 2011-01-1517 2011 https://doi.org/10.4271/2011-01-1517
- Jäger , A. , Decker , F. , Hartmann , M. , Islam , M. , Lemke , T. , et al. Numerical and Experimental Investigations of the Noise Generated by a Flap in a Simplified HVAC Duct 14th AIAA/CEAS Aeroacoustics Conference 2008 10.2514/6.2008-2902
- Millo , F. , Sapio , F. , Peiretti Paradisi , B. , Arina , R. , et al. Computational Aeroacoustic Analysis of Noise Mitigation Potential of Complex Exhaust Systems 21. Internationales Stuttgarter Symposium Springer 2021 https://doi.org/10.1007/978-3-658-33466-6_36
- Bailly , C. and Juvé , D. A Stochastic Approach to Compute Subsonic Noise Using Linearized Euler’s Equations 5th AIAA/CEAS Aeroacoustics Conference and Exhibit 496 506 1999 10.2514/6.1999-1872
- Krug , C. and Benetti , A. 2018
- https://mdx.plm.automation.siemens.com/star-ccm-plus
- Spalart , P.R. , Jou , W.H. , Strelets , M.K. , and Allmaras , S.R. Comments on the Feasibility of LES for Wings and on a Hybrid RANS/LES Approach First AFOSR International Conference on DNS/LES Greyden Press 4 8 1997
- Shur , M.L. , Spalart , P.R. , and Strelets , M.K. Jet Noise Computation Based on Enhanced DES Formulations Accelerating the RANS-to-LES Transition in Free Shear Layers Int. J. Aeroacoustics 15 6-7 2016 595 613 10.1177/1475472X16659388
- Caraeni , M. , Alastairwest , W. , and Caraeni , D. Turbulent Jet Noise Simulation and Propagation Using a 3rd Order MUSCL/CD Scheme on Unstructured Grid and Ffowcs-Williams Hawkings Springer Proc. Phys. 185 2016 389 397 10.1007/978-3-319-30602-5_49
- Shih , T.H. , Liou , W.W. , Shabbir , A. , Yang , Z. et al. A New k-ϵ Eddy Viscosity Model for High Reynolds Number Turbulent Flows Comput. Fluids 24 3 1995 227 238 10.1016/0045-7930(94)00032-T
- Menter , F.R. and Kuntz , M. Adaptation of Eddy-Viscosity Turbulence Models to Unsteady Separated Flow Behind Vehicles The Aerodynamics of Heavy Vehicles: Trucks, Buses, and Trains. Lecture Notes in Applied and Computational Mechanics Springer 2004 339 352 10.1007/978-3-540-44419-0_30
- Wagner , C. , Hüttl , T. , and Sagaut , P. Large-Eddy Simulation for Acoustics Cambridge Univ. Press 2007 1 441 10.1017/CBO9780511546143
- Wiemeler , D. , Jauer , A. , and Brand , J.F. Flow Noise Level Prediction Methods of Exhaust System Tailpipe Noise SAE Techical Paper 2008-01-0404 2008 https://doi.org/10.4271/2008-01-0404
- West , A. and Caraeni , M. Jet Noise Prediction Using a Permeable FW-H Solver 21st AIAA/CEAS Aeroacoustics Conference 2016 10.2514/6.2015-2371
- Tennekes , H. and Lumley , J.L. A First Course in Turbulence The MIT Press 1972 10.7551/mitpress/3014.001.0001
- Proudman , I. The Generation of Noise by Isotropic Turbulence Proc. R. Soc. London. Ser. A. Math. Phys. Sci. 214 1116 1952 119 132 10.1098/rspa.1952.0154
- Curle , N. The Influence of Solid Boundaries Upon Aerodynamic Sound Proc. R. Soc. London. Ser. A. Math. Phys. Sci. 231 1187 1955 505 514 10.1098/rspa.1955.0191