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Joint acoustic and wall-pressure measurements on a model A-pillar vortex

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Abstract

This study investigates the noise generation and radiation of a three-dimensional A-pillar vortex, which is a three-dimensional unsteady structure found on most automotive models. A small model is used to generate the vortex and is tested in an anechoic wind tunnel. The flow is validated against the literature using wall-pressure measurements: the maxima in the fluctuating pressure coefficient are found under the vortical structure. A 31-channel acoustic beamforming array is deployed to identify the noise sources on this model in 2 perpendicular planes. The A-pillar is identified to be the main noise mechanism over a wide range of frequency (between 1 and 8 kHz), with a monopolar radiation in a plane perpendicular to the flow. Some coherence between the fluctuating wall-pressure and the far-field radiation is found around 1 kHz, but only for wall-pressure sensors located in the area outside of the vortical structure, where the fluctuating pressure coefficient is low. An additional experiment with an external noise source is conducted and confirms that the wall-pressure fluctuations convected by the vortex structure mask the acoustic pressure fluctuations which result in a low coherence level in the area where the fluctuating pressure coefficient is the highest. This experiment shows that wall-pressure measurements need to be associated to microphone array measurements to carry out a thorough experimental aeroacoustic study of a complex 3D system such as the A-pillar vortex.

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References

  • Ahmed SR, Ramm G, Faltin G (1984) Some salient features of the time-averaged ground vehicle wake. SAE Trans 93(2):473–503

    Google Scholar 

  • Alam F, Watkins S, Zimmer G (2003) Mean and time-varying flow measurements on the surface of a family of idealised road vehicles. Exp Thermal Fluid Sci 27:639–654

    Article  Google Scholar 

  • Aljure DE, Lehmkuhl O, Rodriguez I, Oliva A (2014) Flow and turbulent structures around simplified car models. Comput Fluids 96:122–135

    Article  Google Scholar 

  • Aljure DE, Calafell J, Baez A, Oliva A (2018) Flow over a realistic car model: wall modeled large eddy simulations assessment. J Wind Eng Ind Aerodyn 174:225–240

    Article  Google Scholar 

  • Arguillat B, Ricot D, Bailly C, Robert G (2010) Measured wavenumber: frequency spectrum associated with acoustic and aerodynamic wall pressure fluctuations. J Acoust Soc Am 128(4):1647–1655

    Article  Google Scholar 

  • Brooks TF, Humphreys WM (1999) Effect of directional array size on the measurement of airframe noise components. In: 5th AIAA Aeroacoustics Conference, Bellevue, Washington

  • Brooks T, Humphreys W (2003) Flap-edge aeroacoustic measurements and predictions. J Sound Vibration 261:31–74

    Article  Google Scholar 

  • Cheng SY, Tsubokura M, Nakashima T, Okada Y, Nouzawa T (2012) Numerical quantification of aerodynamic damping on pitching of vehicle-inspired bluff body. J Fluids Struct 30:188–204

    Article  Google Scholar 

  • Chiariotti P, Martarelli M, Castellini P (2019) Acoustic beamforming for noise source localization: reviews, methodology and applications. Mech Syst Signal Process 120:422–448

    Article  Google Scholar 

  • Conan B, Anthoine J, Planquart P (2011) Experimental aerodynamic study of a car-type bluff body. Exp Fluids 50:1273–1284

    Article  Google Scholar 

  • Cooper KR (1993) Bluff-body aerodynamics as applied to vehicles. J Wind Eng Ind Aerodyn 49:1–22

    Article  Google Scholar 

  • Debert S, Pachebat M, Valeau V, Gervais Y (2011) Ensemble-empirical-mode-decomposition method for instantaneous spatial-multi-scale decomposition of wall-pressure fluctuations under a turbulent flow. Exp Fluids 50:339–350

    Article  Google Scholar 

  • Fischer J (2014) Identification de sources aéroacoustiques au voisinage de corps non profilés par formation de voies fréquentielle et temporelle. PhD thesis, University of Poitiers

  • Fischer J, Valeau V, Brizzi LE (2016) Beamforming of aeroacoustic sources in the time domain: an investigation of the intermittency of the noise radiated by a forward-facing step. J Sound Vibration 383:464–485

    Article  Google Scholar 

  • Fritschi L (2011) Burden of disease from environmental noise, quantification of healthy life years lost in Europe. World Health Organization, Regional Office for Europe

  • Fuller J, Best M, Garret N, Passmore M (2013) The importance of unsteady aerodynamics to road vehicle dynamics. J Wind Eng Ind Aerodyn 117:1–10

    Article  Google Scholar 

  • Haruna S, Nouzawa T, Kamimoto I (1990) An experimental analysis and estimation of aerodynamic noise using a production vehicle. In: SAE technical paper series No. 900316, Detroit, Michigan

  • Hoarau C (2006) Mesures multipoints pression-vitesse pour l’analyse de l’aérodynamique d’écoulements décollés instationnaires - application aux véhicules terrestres, PhD thesis, University of Poitiers

  • Hoarau C, Borée J, Laumonier J, Gervais Y (2008) Unsteady wall pressure field of a model A-pillar conical vortex. Int J Heat Fluid Flow 29:812–819

    Article  Google Scholar 

  • Howe MS (2003) Theory of vortex sound. Cambridge University Press, Cambridge

    MATH  Google Scholar 

  • Hucho WH (1998) Aerodynamics of road vehicles : from fluid mechanics to vehicle engineering, 4th edn. Society of Automotive Engineers, U.S

    Google Scholar 

  • Islam A, Gaylard A, Thornber B (2017) A detailed statistical study of unsteady wake dynamics from automotive bluff bodies. J Wind Eng Ind Aerodyn 171:161–177

    Article  Google Scholar 

  • Jacob MC, Jérôme Boudet J, Casalino D, Michard M (2005) A rod-airfoil experiment as benchmark for broadband noise modeling. Theor Comput Fluid Dyn 19:171–196

    Article  Google Scholar 

  • Kleber A (2001) Simulation of air flow around an opel astra vehicle with fluent, Journal articles by FLUENT software users, JA132

  • Largeau JP (2004) Analyse expérimentale de la dynamique et du rayonnement acoustique d’un écoulement de marche montante. PhD thesis, University of Poitiers

  • Lehugeur B, Gilliéron P, Kourta A (2010) Experimental investigation on longitudinal vortex control over a dihedral bluff body. Exp Fluids 48:33–48

    Article  Google Scholar 

  • Levy B, Brancher P (2013) Topology and dynamics of the A-pillar vortex. Phys Fluids 25:1–15

    Article  Google Scholar 

  • Levy B, Brancher P, Giovannini A (2008) Experimental characterization of the velocity and wall pressure fields of an A-pillar vortex. In: 14th AIAA/CEAS Aeroacoustics Conference, Vancouver, Canada

  • Merino-Martínez R, Sijtsma P, Snellen M, Ahlefeldt T, Antoni J, Bahr CJ, Blacodon D, Ernst D, Finez A, Funke S, Geyer TF, Haxter S, Herold G, Huang X, Humphreys WM, Leclère Q, Malgoezar A, Michel U, Padois T, Pereira A, Picard C, Sarradj E, Siller H, Simons DG, Spehr C (2019) A review of acoustic imaging methods using phased microphone arrays. CEAS Aeronaut J 10:197–230

    Article  Google Scholar 

  • Moraes L, Sicot C, Paille F, Borée J (2012) Passive control of flow in a A-pillar region in the presence of uniform or turbulent upstream flow. In: Proceedings of ASME, Rio Grande, Puerto Rico

  • Mueller TJ (2002) Aeroacoustic measurements. Editor: T.J. Springer

  • Murad N, Naser J, Alam F, Watkins S (2013) Computational fluid dynamics study of vehicle A-pillar aero-acoustics. Appl Acoust 74:882–896

    Article  Google Scholar 

  • Oppenheim AV, Schafer RW, Buck JR (1999) Discrete-time signal processing. Prentice-hall Signal Processing Series

  • Padois T, Prax C, Valeau V (2013) Numerical validation of shear flow corrections for beamforming source localisation in open wind-tunnels. Appl Acoust 74:591–601

    Article  Google Scholar 

  • Priede T (1971) Origins of automotive vehicle noise. J Sound Vib 15(1):61–73

    Article  Google Scholar 

  • Rakotoarisoa I, Fischer J, Valeau V, Marx D, Prax C, Brizzi LE (2014a) Time-domain delay-and-sum beamforming for time-reversal detection of intermittent acoustic sources in flows. J Acoust Soc Am 136(5):2675–2686

    Article  Google Scholar 

  • Rakotoarisoa I, Fischer J, Marx D, Valeau V, Prax C, Brizzi LE, Nana C (2014b) Detection of non-stationary aeroacoustic sources by time-domain imaging methods. In: 20th AIAA/CEAS Aeroacoustics Conference, Atlanta, GA

  • Rossitto G, Sicot C, Ferrand V, Borée J, Harambat F (2016) Influence of afterbody rounding on the pressure distribution over a fastback vehicle. Exp Fluids 57(43):1–12

    Google Scholar 

  • Ruiz T, Sicot C, Brizzi L, Laumonier J, Borée J, Gervais Y (2009) Unsteady near-wake of a flat disk normal to the wall. Exp Fluids 47(4):637–653

    Article  Google Scholar 

  • Sarradj E (2012) Three-dimensional acoustic source mapping with different beamforming steering vector formulations. Advances in Acoustics and Vibration 2012

  • Shojaefard MH, Goudarzi K, Fotouhi H (2009) Numerical study of airflow around vehicle a-pillar region and wind noise generation prediction. Am J Appl Sci 6(2):276–284

    Article  Google Scholar 

  • Sijtsma P (2007) CLEAN based on spatial source coherence. Int J Aeroacoust 6(4):357–374

    Article  Google Scholar 

  • Watanabe M (1978) The effect of body shapes on wind noise. SAE Technical Paper 780266

  • Watkins S (2010) Vehicle noise and vibration refinement. Editor: Xu Wang. Woodhead Publishing

Download references

Acknowledgements

The authors wish to thank Laurent Philippon, Pascal Biais, Philippe Szeger and Jean-Christophe Vergez for their technical support to this work.

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Authors and Affiliations

  1. School of Mechanical and Manufacturing Engineering, UNSW Sydney High Street, Sydney, NSW, 2052, Australia

    Jeoffrey Fischer

  2. Institut PPRIME UPR 3346, CNRS-Université de Poitiers-ENSMA, B17 - 6, rue Marcel Doré, 86022, Poitiers Cedex, France

    Vincent Valeau, Laurent-Emmanuel Brizzi & Janick Laumonier

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  1. Jeoffrey Fischer
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  2. Vincent Valeau
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  3. Laurent-Emmanuel Brizzi
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  4. Janick Laumonier
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Correspondence to Jeoffrey Fischer.

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Fischer, J., Valeau, V., Brizzi, LE. et al. Joint acoustic and wall-pressure measurements on a model A-pillar vortex. Exp Fluids 61, 54 (2020). https://doi.org/10.1007/s00348-020-2880-5

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  • DOI: https://doi.org/10.1007/s00348-020-2880-5

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