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Acoustic theory of the many-bladed contra-rotating propeller: physics of the wake interaction noise critical sources

Published online by Cambridge University Press:  07 October 2019

A. B. Parry*
Affiliation:
30 Ypres Road, Allestree, Derby DE22 2LZ, UK
M. J. Kingan
Affiliation:
Department of Mechanical Engineering, University of Auckland, Auckland 1010, New Zealand
*
Email address for correspondence: anthony.parry.pig@gmail.com

Abstract

In the theory of interaction noise from contra-rotating propellers with many blades, the usual far-field radiation formulae can be re-cast as a double integral, over a source surface, which can be evaluated asymptotically solely in terms of the contributions from critical points. The paper shows that these critical points have a particularly interesting physical meaning. They relate to locations on an event line, running between hub and tip, that represent the locus of the wake–blade interactions at a fixed point in time. The event line rotates at the speed of the spinning interaction tone but does not coincide with the radial variation in either the wake location or the rear blade leading edge. At the precise critical locations on the event line, it is shown that the Mach number of the event line is unity in the direction of the observer (the sonic condition) and the tangent to the event line – at a fixed time – is normal to a line drawn between it and the observer (the normal-edge condition). The zero-mode case is also considered, for which we show that, even though the event line rotates at infinite speed, there can still exist locations that satisfy the sonic and normal-edge conditions. The paper also discusses the physical meaning of the lower-order boundary solutions from the hub and tip.

Type
JFM Rapids
Copyright
© 2019 Cambridge University Press 

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References

Adamczyk, J. J. 1974 Passage of a swept airfoil through an oblique gust. J. Aircraft 11, 281287.Google Scholar
Amiet, R. K. 1988 Thickness noise of a propeller and its relation to blade sweep. J. Fluid Mech. 192, 535560.Google Scholar
Brandvik, T., Hall, C. E. & Parry, A. B. 2012 Angle-of-attack effects on counter-rotating propellers at takeoff. In ASME Turbo Expo 2012, Copenhagen, Denmark, 11–15 June, ASME paper GT2012-69901.Google Scholar
Chapman, C. J. 1992 Time-domain asymptotics and the method of stationary phase. Proc. R. Soc. Lond. A 437, 2540.Google Scholar
Crighton, D. G. & Parry, A. B. 1991 Asymptotic theory of propeller noise II: Supersonic single-rotation propeller. AIAA J. 29, 20312037.Google Scholar
Crighton, D. G. & Parry, A. B. 1992 Higher approximations in the asymptotic theory of propeller noise. AIAA J. 30, 30233039.Google Scholar
Ekoule, C. E., Kingan, M. J., McAlpine, A. M., Sohoni, N. & Parry, A. B. 2015 Use of a hybrid CFD/analytical method for the prediction of advanced open rotor tone noise. In 21st AIAA/CEAS Aeroacoustics Conference, Dallas, TX, 22–26 June, AIAA Paper 2015-2357.Google Scholar
Ekoule, C. E., McAlpine, A. M., Parry, A. B., Kingan, M. J. & Sohoni, N. 2017 Development of a hybrid method for the prediction of advanced open rotor tone noise. In 23rd AIAA/CEAS Aeroacoustics Conference, Denver, CO, 5–9 June, AIAA Paper 2017-3870.Google Scholar
Envia, E. 1994 Asymptotic theory of supersonic propeller noise. AIAA J. 32 (2), 239246.Google Scholar
Envia, E. 2015 Aeroacoustic analysis of a high-speed open rotor. Intl J. Aeroacoust. 14 (3–4), 569606.Google Scholar
Evers, I. & Peake, N. 2000 Noise generation by high-frequency gusts interacting with an airfoil in transonic flow. J. Fluid Mech. 411, 91130.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, 2552.Google Scholar
Glegg, S. A. L. 1999 The response of a swept blade row to a three-dimensional gust. J. Sound Vib. 227 (1), 2964.Google Scholar
Graham, J. M. R. 1970 Lifting surface theory for the problem of an arbitrarily yawed sinusoidal gust incident on a thin aerofoil in incompressible flow. Aeronaut. Q. 21, 182198.Google Scholar
Hanson, D. B. 1980 Helicoidal surface theory for harmonic noise of propellers in the far field. AIAA J. 18, 12131220.Google Scholar
Hanson, D. B. 1985 Noise of counter-rotation propellers. J. Aircraft 22, 609617.Google Scholar
Kingan, M. J. & Parry, A. B. 2019 Acoustic theory of the many-bladed contra-rotating propeller: analysis of the effects of blade sweep on wake interaction noise. J. Fluid Mech. 868, 385427.Google Scholar
Myers, M. R. & Kerschen, E. J. 1995 Influence of incidence angle on sound generation by airfoils interacting with high-frequency gusts. J. Fluid Mech. 292, 271304.Google Scholar
Myers, M. R. & Kerschen, E. J. 1997 Influence of camber on sound generation by aerfoils interacting with high-frequency gusts. J. Fluid Mech. 353, 221259.Google Scholar
Parry, A. B.1988 Theoretical prediction of counter-rotating propeller noise. PhD thesis, University of Leeds.Google Scholar
Parry, A. B. 1995 The effect of blade sweep on the reduction and enhancement of supersonic propeller noise. J. Fluid Mech. 293, 181206.Google Scholar
Parry, A. B. & Crighton, D. G. 1989a Asymptotic theory of propeller noise. I. Subsonic single-rotation propeller. AIAA J. 27, 11841190.Google Scholar
Parry, A. B. & Crighton, D. G. 1989b Prediction of counter-rotation propeller noise. In 12th Aeroacoustics Conference, San Antonio, TX, Apr 10–12, AIAA Paper 89-1141.Google Scholar
Peake, N. & Boyd, W. K. 1993 Approximate method for the prediction of propeller noise near-field effects. J. Aircraft 30 (5), 603610.Google Scholar
Peake, N. & Crighton, D. G. 1991a An asymptotic theory of near-field propeller acoustics. J. Fluid Mech. 232, 285301.Google Scholar
Peake, N. & Crighton, D. G. 1991b Lighthill quadrupole radiation in supersonic propeller acoustics. J. Fluid Mech. 223, 363382.Google Scholar
Peake, N. & Kerschen, E. J. 1997 Influence of mean loading on noise generated by the interaction of gusts with a flat-plate cascade: upstream radiation. J. Fluid Mech. 347, 315346.Google Scholar
Prentice, P. R. 1994a Time-domain asymptotics. I. General theory for double integrals. Proc. R. Soc. Lond. A 446, 341360.Google Scholar
Prentice, P. R. 1994b Time-domain asymptotics. II. Application to propeller acoustics. Proc. R. Soc. Lond. A 446, 361380.Google Scholar
Saravanamuttoo, H. I. H., Rogers, G. F. C., Cohen, H., Straznicky, P. V. & Nix, A. V. 2017 Gas Turbine Theory, 7th edn. Pearson.Google Scholar
Tyler, J. M. & Sofrin, T. G. 1962 Axial flow compressor noise studies. SAE Trans. 70, 309332.Google Scholar