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Assessment of surface roughness for a ‘silent’ aircraft

Part of: Sustainable Aerospace

Published online by Cambridge University Press:  27 January 2016

Y. Liu
Y. Liu*
Affiliation:
Department of Engineering, University of Cambridge, Cambridge, UK
*
[email protected]
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Abstract

Boundary-layer noise produced by rough surfaces is a potential contributor to airframe noise. In this paper, an attempt is made to assess the surface roughness noise for a conceptual Silent Aircraft design SAX-40 using a prediction model described in previous theoretical work (Liu and Dowling(12)). Estimates of three idealised test cases show that surface roughness could produce a relatively high noise level and enhance the trailing-edge noise somewhat. Roughness height and roughness density are two significant parameters which affect surface roughness noise, with roughness height having the more dominant effect. The distribution of roughness noise sources decreases in the streamwise direction on the SAX-40 surface. Two candidate rough surfaces are selected for SAX-40 to keep surface roughness noise at a negligible level and to meet an aggressive noise target.

Type
Research Article
Information
The Aeronautical Journal , Volume 117 , Issue 1189 , March 2013 , pp. 283 - 298
Copyright
Copyright © Royal Aeronautical Society 2013 

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Footnotes

p1

Currently at: Department of Mechanical Engineering Sciences, University of Surrey, Guildford, UK

References

1. The Cambridge-MIT Insititute. The ‘silent’ aircraft initiative, Website, 2006. http://silentaircraft.org.Google Scholar
2. Dowling, A.P. and Hynes, T.P. Towards a silent aircraft, Aeronaut J, 2006, 110, (1100), pp 487–494.Google Scholar
3. Dowling, A.P. The silent aircraft initiative — overview, 2007, AIAA Paper No 2007-0452.Google Scholar
4. Hileman, J.I., Reynolds, T.G., de la Rosa Blanco, E., Law, T.R. and Thomas, S.P. Development of approach procedures for silent aircraft, 2007, AIAA Paper No 2007-0451.Google Scholar
5. Hileman, J.I., Spakovszky, Z.S., Drela, M. and Sargeant, M.A. Airframe design for ‘silent aircraft’, 2007, AIAA Paper No 2007-0453.Google Scholar
6. Crighton, D.G. Airframe noise chapter, Aeroacoustics of Flight Vehicles: Theory and Practice, Vol 1: Noise Sources, 1994, Hubbard, H.H. (Ed), Acoustical Society of America, New York, USA.Google Scholar
7. Luers, J.K. Wing contamination: Threat to safe flight, Astronaut & Aeronaut, 1983, 21, (11), pp 54–59.Google Scholar
8. Howe, M.S. On the generation of sound by turbulent boundary layer flow over a rough wall, Proc R Soc London, 1984, A395, pp 247–263.Google Scholar
9. Howe, M.S. The influence of viscous surface stress on the production of sound by a turbulent boundary layer over a rough wall, J Sound Vib, 1986, 104, (1), pp 29–39.Google Scholar
10. Howe, M.S. The turbulent boundary-layer rough-wall pressure spectrum at acoustic and subconvective wavenumbers, Proc R Soc London, 1988, A415, pp 141–161.Google Scholar
11. Howe, M.S. Surface pressures and sound by turbulent flow over smooth and rough walls, J Acoust Soc Am, 1991, 90, (2), pp 1041–1047.Google Scholar
12. Liu, Y. and Dowling, A.P. Assessment of the contribution of surface roughness to airframe noise, AIAA J, 2007, 45, (4), pp 855–869.Google Scholar
13. Liu, Y., Dowling, A.P. and Shin, H.-C. Measurement and simulation of surface roughness noise using phased microphone arrays, J Sound Vib, 2008, 314, (1-2), pp 95–112.Google Scholar
14. Corcos, G.M. The structure of the turbulent pressure field in boundary-layer flows, J Fluid Mech, 1964, 18, (3), pp 353–378.Google Scholar
15. Efimtsov, B.M. Characteristics of the field of turbulent wall pressure fluctuations at large Reynolds numbers, Phys Acoust, 1982, 28, (4), pp 289–292.Google Scholar
16. Smol'yakov, A.V. and Tkachenko, V.M. Model of a field of pseudosonic turbulent wall pressures and experimental data, Phys Acoust, 1991, 37, (6), pp 627–631.Google Scholar
17. Chase, D.M. Modeling the wavevector-frequency spectrum of turbulent boundary layer wall pressure, J Sound Vib, 1980, 70, (1), pp 29–67.Google Scholar
18. Chase, D.M. The character of the turbulent wall pressure spectrum at subconvective wavenumbers and a suggested comprehensive model, J Sound Vib, 1987, 112, (1), pp 125–147.Google Scholar
19. Ahn, B. Modelling Unsteady Wall Pressures beneath Turbulent Boundary Layers, 2005, PhD thesis, Department of Engineering, University of Cambridge, Cambridge, UK.Google Scholar
20. Blake, W.K. Turbulent bounday-layer wall-pressure fluctuations on smooth and rough walls, J Fluid Mech, 1970, 44, (4), pp 637–660.Google Scholar
21. Dowling, A.P. and Ffowcs Williams, J.E. Sound and Sources of Sound, 1983, Ellis Horwood, Chichester, UK.Google Scholar
22. Mills, A.F. and Hang, X. On the skin friction coefficient for a fully rough flat plate, ASME J Fluids Eng, 1983, 105, pp 364–365.Google Scholar
23. Krogstad, P.A., Antonia, R.A. and Browne, L.W.B. Comparison between rough- and smooth-wall turbulent boundary layers, J Fluid Mech, 1992, 245, pp 599–617.Google Scholar
24. Schlichting, H. Boundary Layer Theory, McGraw-Hill, New York, 7th edition, 1979.Google Scholar
25. Howe, M.S. Acoustics of Fluid-Structure Interactions, 1998, Cambridge University Press, Cambridge, UK.Google Scholar
26. ESDU. The mean skin friction coefficient for a rough flat plate with a turbulent two-demensional boundary layer in compressible adiabatic flow, with application to wedges, cylinders and cones, 1973, Engineering Sciences Data Unit (ESDU) Aerodynamics Data, Item 2c-73016, ESDU International, London, UK.Google Scholar
27. Duncan, W.J., Thom, A.S. and Young, A.D. Mechanics of Fluids, 2nd Edition, 1970, Edward Arnold, London, UK.Google Scholar
28. Evans, P. An introduction to aircraft noise lateral attenuation, 1981, Engineering Sciences Data Unit (ESDU) Lateral Attenuation Manual, Item 81035, ESDU International, London, UK.Google Scholar
29. ESDU. Evaluation of the attenuation of sound by a uniform atmosphere, 1978, Engineering Sciences Data Unit (ESDU), Item 78002, ESDU International, London, UK.Google Scholar
30. ESDU. Estimation of lateral attenuation of air-to-ground jet or turbofan aircraft noise in one-third octave bands, 1982, Engineering Sciences Data Unit (ESDU), Item 82027, ESDU International, London, UK.Google Scholar