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Performance and mechanism of sinusoidal leading edge serrations for the reduction of turbulence–aerofoil interaction noise

Published online by Cambridge University Press:  04 April 2017

P. Chaitanya Open the ORCID record for P. Chaitanya [Opens in a new window] ,
P. Joseph ,
S. Narayanan ,
C. Vanderwel Open the ORCID record for C. Vanderwel [Opens in a new window] ,
J. Turner ,
J. W. Kim  and
B. Ganapathisubramani
P. Chaitanya*
Affiliation:
University of Southampton, Southampton SO17 1BJ, UK
P. Joseph
Affiliation:
University of Southampton, Southampton SO17 1BJ, UK
S. Narayanan
Affiliation:
University of Southampton, Southampton SO17 1BJ, UK
C. Vanderwel
Affiliation:
University of Southampton, Southampton SO17 1BJ, UK
J. Turner
Affiliation:
University of Southampton, Southampton SO17 1BJ, UK
J. W. Kim
Affiliation:
University of Southampton, Southampton SO17 1BJ, UK
B. Ganapathisubramani
Affiliation:
University of Southampton, Southampton SO17 1BJ, UK
*
†Email address for correspondence: [email protected]
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Abstract

This paper presents the results of a detailed experimental investigation into the effectiveness of sinusoidal leading edge serrations on aerofoils for the reduction of the noise generated by the interaction with turbulent flow. A detailed parametric study is performed to investigate the sensitivity of the noise reductions to the serration amplitude and wavelength. The study is primarily performed on flat plates in an idealized turbulent flow, which we demonstrate captures the same behaviour as when identical serrations are introduced onto three-dimensional aerofoils. The influence on the noise reduction of the turbulence integral length scale is also studied. An optimum serration wavelength is identified whereby maximum noise reductions are obtained, corresponding to when the transverse integral length scale is approximately one-fourth the serration wavelength. This paper proves that, at the optimum serration wavelength, adjacent valley sources are excited incoherently. One of the most important findings of this paper is that, at the optimum serration wavelength, the sound power radiation from the serrated aerofoil varies inversely proportional to the Strouhal number $St_{h}=fh/U$, where $f$, $h$ and $U$ are frequency, serration amplitude and flow speed, respectively. A simple model is proposed to explain this behaviour. Noise reductions are observed to generally increase with increasing frequency until the frequency at which aerofoil self-noise dominates the interaction noise. Leading edge serrations are also shown to reduce aerofoil self-noise. The mechanism for this phenomenon is explored through particle image velocimetry measurements. Finally, the lift and drag of the serrated aerofoil are obtained through direct measurement and compared against the straight edge baseline aerofoil. It is shown that aerodynamic performance is not substantially degraded by the introduction of the leading edge serrations on the aerofoil.

JFM classification

Acoustics: Acoustics Acoustics: Aeroacoustics Acoustics: Noise control
Type
Papers
Information
Journal of Fluid Mechanics , Volume 818 , 10 May 2017 , pp. 435 - 464
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Copyright
© 2017 Cambridge University Press 

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Footnotes

‡

Present address: Indian Institute of Technology (ISM), Dhanbad, Jharkhand 826004, India

References

Bachmann, T., Kln, S., Baumgartner, W., Klaas, M., Schrder, W. & Wagner, H. 2007 Morphometric characterisation of wing feathers of the barn owl tyto alba pratincola and the pigeon columba livia. Front. Zoology 4 (1), 23.CrossRefGoogle ScholarPubMed
Blake, W. K. 1970 Turbulent boundary-layer wall-pressure fluctuations on smooth and rough walls. J. Fluid Mech. 44 (04), 637–660.Google Scholar
Brooks, T. F., Pope, D. S. & Marcolini, M. A. 1989 Airfoil Self-Noise and Prediction, vol. 1218. National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Division.Google Scholar
Chaitanya, P., Gill, J., Narayanan, S., Joseph, P., Vanderwel, C., Zhang, X. & Ganapathisubramani, B.2015a Aerofoil geometry effects on turbulence interaction noise. AIAA Paper 2015-2830.Google Scholar
Chaitanya, P., Narayanan, S., Joseph, P., Vanderwel, C., Turner, J., Kim, J. W. & Ganapathisubramani, B.2015b Broadband noise reduction through leading edge serrations on realistic aerofoils. AIAA Paper 2015-2202.Google Scholar
Chong, T. P., Joseph, P. F. & Davies, P. O. A. L. 2008 A parametric study of passive flow control for a short, high area ratio 90° curved diffuser. Trans. ASME J. Fluids Engng 130 (11), 111104.Google Scholar
Chong, T. P., Vathylakis, A., McEwen, A., Kemsley, F., Muhammad, C. & Siddiqi, S.2015 Aeroacoustic and aerodynamics performance of an aerofoil subjected to sinusoidal leading edges. AIAA Paper 2015-2200.Google Scholar
Clair, V., Polacsek, C., Garrec, T. L., Reboul, G., Gruber, M. & Joseph, P. 2013 Experimental and numerical investigation of turbulence-airfoil noise reduction using wavy edges. AIAA J. 51 (11), 2695–2713.Google Scholar
Collins, F. G. 1981 Boundary layer control on wings using sound and leading edge serrations. AIAA J. 19 (2), 129–130.Google Scholar
Devenport, W. J., Staubs, J. K. & Glegg, S. A. L. 2010 Sound radiation from real airfoils in turbulence. J. Sound Vib. 329, 3470–3483.Google Scholar
Evers, I. & Peake, N. 2002 On sound generation by the interaction between turbulence and a cascade of airfoils with non-uniform mean flow. J. Fluid Mech. 463, 25–52.CrossRefGoogle Scholar
Favier, J., Pinelli, A. & Piomelli, U. 2012 Control of the separated flow around an airfoil using a wavy leading edge inspired by humpback whale flippers. C. R. Méc. 340 (1–2), 107–114.Google Scholar
Fish, F. E. & Lauder, G. V. 2006 Passive and active flow control by swimming fishes and mammals. Annu. Rev. Fluid Mech. 38, 193–224.Google Scholar
Fish, F. E., Weber, P. W., Murray, M. M. & Howle, L. E. 2011 The tubercles on humpback whales flippers: application of bio-inspired technology. Integr. Compar. Biol. 51 (1), 203–213.CrossRefGoogle ScholarPubMed
Gershfeld, J. 2004 Leading edge noise from thick foils in turbulent flows. J. Acoust. Soc. Am. 116, 1416–1426.Google Scholar
Gill, J., Zhang, X. & Joseph, P. 2013 Symmetric airofils geometry effects on leading edge noise. J. Acoust. Soc. Am. 34 (4), 2669–2680.Google Scholar
Gruber, M.2012 Airfoil noise reduction by edge treatments. PhD thesis, University of Southampton, ISVR.Google Scholar
Gruber, M., Joseph, P. & Azarpeyvand, M.2013 An experimental investigation of novel trailing edge geometries on airfoil trailing edge noise reduction. AIAA Paper 2013-2011.Google Scholar
Haeri, S., Kim, J. W., Narayanan, S. & Joseph, P.2014 3D calculations of aerofoil–turbulence interaction noise and the effect of wavy leading edges. AIAA Paper 2014-2325.Google Scholar
Hansen, K. L., Kelso, R. M. & Dally, B. B. 2011 Performance variations of leading-edge tubercles for distinct airfoil profiles. AIAA J. 49 (1), 185–194.Google Scholar
Hersh, A. S., Soderman, P. T. & Hayden, R. E. 1974 Investigation of acoustic effets of leading edge serrations on airfoils. J. Aircraft 11 (4), 197–202.Google Scholar
Johari, H., Henoch, C., Custodio, D. & Levshin, A. 2007 Effects of leading-edge protuberances on airfoil performance. AIAA J. 45 (11), 2634–2642.Google Scholar
Kim, J. W., Haeri, S. & Joseph, P. F. 2016 On the reduction of aerofoil–turbulence interaction noise associated with wavy leading edges. J. Fluid Mech. 792, 526–552.Google Scholar
Lau, A. S. H., Haeri, S. & Kim, J. W. 2013 The effect of wavy leading edges on aerofoil–gust interaction noise. J. Sound Vib. 332, 6234–6253.CrossRefGoogle Scholar
Lysak, P. D., Capone, D. E. & Jonson, M. L. 2013 Prediction of high frequency gust response with airofoil thickness effects. J. Fluids Struct. 39, 258–274.Google Scholar
Lyu, B., Azarpeyvand, M. & Sinayoko, S.2016 Noise prediction for serrated leading-edges. AIAA Paper 2016-2740.Google Scholar
Miklosovic, D. S., Murray, M. M. & Howle, L. E. 2007 Experimental evaluation of sinusoidal leading edges. J. Aircraft 44 (4), 1404–1408.CrossRefGoogle Scholar
Miklosovic, D. S., Murray, M. M., Howle, L. E. & Fish, F. E. 2004 Leading-edge tubercles delay stall on humpback whale (megaptera novaeangliae) flippers. Phys. Fluids 16 (5), L39.CrossRefGoogle Scholar
Moriarty, P. J., Guidati, G. & Migliore, P.2005 Prediction of turbulent inflow and trailing-edge noise for wind turbines. AIAA Paper 2005-2881.Google Scholar
Narayanan, S., Chaitanya, P., Haeri, S., Joseph, P., Kim, J. W. & Polacsek, C. 2015 Airfoil noise reductions through leading edge serrations. Phys. Fluids 27, 025109.Google Scholar
Narayanan, S., Joseph, P., Haeri, S., Kim, J. W., Chaitanya, P. & Polacsek, C.2014 Noise reduction studies from the leading edge of serrated flat plates. AIAA Paper 2014-2320.Google Scholar
Roger, M. 2010 Analytical modeling of the potential-interaction noise of a rotor due to a downstream rod. In 13th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, pp. 516–522.Google Scholar
Roger, M., Schram, C., Santana, C. & De, L.2013 Reduction of airfoil turbulence-impingement noise by means of leading-edge serrations and/or porous materials. AIAA Paper 2013-2108.Google Scholar
Rostamzadeh, N., Kelso, R. M., Dally, B. B. & Hansen, K. L. 2013 The effect of undulating leading-edge modifications on NACA 0021 airfoil characteristics. Phys. Fluids 25, 117101.Google Scholar
Skillen, A., Revell, A., Pinelli, A., Piomelli, U. & Favier, J. 2014 Flow over a wing with leading-edge undulations. AIAA J. 53 (2), 464–472.Google Scholar
Soderman, P. T.1972 Aerodynamic effects of leading-edge serrations on a two-dimensional airfoil. NASA Tech. Rep. TM X-2643.Google Scholar
Stalnov, O., Chaitanya, P. & Joseph, P.2015 Prediction of broadband trailing-edge noise based on blake model and amiet theory. AIAA Paper 2015-2526.Google Scholar
Stanway, M. J.2008 Hydrodynamic effects of leading-edge tubercles on control surfaces and in flapping foil propulsion. PhD thesis, Massachusetts Institute of Technology, Cambridge, MA.Google Scholar
Van Nierop, E., Alben, S. & Brenner, M. 2008 How bumps on whale flippers delay stall: an aerodynamic model. Phys. Rev. Lett. 100 (5), 1–4.Google Scholar
Yoon, H. S., Hung, P. A., Jung, J. H. & Kim, M. C. 2011 Effect of the wavy leading edge on hydrodynamic characteristics for flow around low aspect ratio wing. Comput. Fluids 49, 276–289.Google Scholar
Zhang, M. M., Wang, G. F. & Xu, J. Z. 2013 Aerodynamic control of low-Reynolds-number airfoil with leading-edge protuberances. AIAA J. 51 (8), 1960–1971.Google Scholar