Abstract
Lifting surfaces produce noise in operation, and porous materials have been shown to reduce this noise. Acoustic measurements were made on three arrangements of poroelastic material: full-chord impermeability, full-chord porosity, and “mixed” porosity. The results are compared to applicable published data. The noise reduction produced by the mixed porosity arrangement is found to be similar to the fully porous arrangement at low Reynolds numbers. The noise reduction produced by the mixed and fully porous foils shows significant differences at higher Reynolds numbers. A percolation-base physical model to explain elevated noise production at high frequencies is proposed.
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References
T. Brooks, D. Pope, M. Marcolini, Airfoil self-noise and prediction, NASA, vol. 1218, 1989
R. Amiet, Noise due to turbulent flow past a trailing edge. J. Sound Vib. 47(3), 387–393 (1976)
T. Bachmann, S. Klän, W. Baumgartner, M. Klaas, W. Schröder, H. Wagner, Morphometric characterisation of wing feathers of the barn owl Tyto alba pratincola and the pigeon Columba livia. Front. Zool. 4(1), 23 (2007)
E. Sarradj, C. Fritzsche, T. Geyer, Silent owl flight: bird flyover noise measurements. AIAA J. 49(4), 769–779 (2011)
T. Geyer, E. Sarradj, C. Fritzsche, Measurement of the noise generation at the trailing edge of porous airfoils. Exp. Fluids 48, 291–308 (2010)
R. Hayden, R. Chanaud, Method of reducing sound generation in fluid flow systems embodying foil structures and the like. U.S. Patent 3,779,338, 1973
C. Ellett, Noiseless propeller. U.S. Patent 2,340,417, 1 Feb 1944
A. Gupta, T. Maeder, Wind-turbine blade and method for reducing noise in wind turbine. U.S. Patent 7,901,189, 2011
P. Ho, P. Gliebe, Low noise permeable airfoil. U.S. Patent 6,139,259, 2000
D. Kump, N. Lauziere, Method of controlling the permeability of a porous material, and turbine blade formed thereby. U.S. Patent 3,402,914, 24 Sept 1968
P. Hartwich, Porous airfoil and process. U.S. Patent 5,167,387, 1 Dec 1992
R. Mineck, P. Hartwich, Effect of full-chord porosity on aerodynamic characteristics of the NACA 0012 airfoil, NASA, 1996
J. Jaworski, N. Peake, Aerodynamic noise from a poroelastic edge with implications for the silent flight of owls. J. Fluid Mech. 723, 456–479 (2013)
M. Herr, K. S. Rossignol, J. Delfs, M. Mößner, N. Lippitz, Specification of porous materials for low-noise trailing-edge applications, in 20th AIAA/CEAS Aeroacoustics Conference, Atlanta, GA, Paper 3041-2014
M. Herr, A noise reduction study on flow-permeable trailing-edges, Deutsches Zentrum für Luft-und Raumfahrt, Institute of Aerodynamics and Flow Technology, Braunschweig, 2007
T. Brooks, T. Hodgson, Trailing edge noise prediction from measured surface pressures. J. Sound Vib. 78, 69–117 (1981)
J. Katz, A. Plotkin, Low-Speed Aerodynamics (Cambridge University Press, Cambridge, 2001)
J. Williams, L. Hall, Aerodynamic sound generation by turbulent flow in the vicinity of a scattering half plane. J. Fluid Mech. 40(4), 657–670 (1970)
N. Curle, The influence of solid boundaries upon aerodynamic sound. Proc. R. Soc. A 231(1187), 505–514 (1955)
M. Potter, J. Foss, Fluid Mechanics (Great Lakes Press, Okemos, MI, 1982)
S. Hoerner, Fluid-Dynamic Drag (Self-Published, New York, 1965)
S. Yarusevych, P. Sullivan, J. Kawall, On vortex shedding from an airfoil in low-Reynolds-number flows. J. Fluid Mech. 632, 245–271 (2009)
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Hellum, A.M. (2018). Acoustics of a Mixed Porosity Felt Airfoil. In: Ruffa, A., Toni, B. (eds) Advanced Research in Naval Engineering. STEAM-H: Science, Technology, Engineering, Agriculture, Mathematics & Health. Springer, Cham. https://doi.org/10.1007/978-3-319-95117-1_2
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DOI: https://doi.org/10.1007/978-3-319-95117-1_2
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